JP2006170052A - Internal combustion engine control device and method of hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively operate an internal combustion engine in a hybrid vehicle even in a range where the efficiency in a hybrid vehicle is locally low. <P>SOLUTION: In a hybrid system 10, a torque calculation part 100b calculates torque of an engine 200 from torque reaction force of a motor generator MG1. A fuel consumption rate calculation part 100c calculates an instantaneous fuel consumption rate in the engine 200 on the basis of a fuel injection amount and engine rotational speed. A working line updating part 100d updates a working line by executing a working point learning process on the basis of the calculated fuel consumption rate. When the engine 200 has the locally low efficiency range on the working line, a working point setting part 100f sets therein as a working point either having higher efficiency of a working point corresponding to required output or two working points switched and controlled to maintain the required output. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technical field of an internal combustion engine control apparatus and method for a hybrid vehicle that controls an operation state of the internal combustion engine in a hybrid vehicle including an internal combustion engine and a motor generator as a power source.

  As this type of technology, there is a vehicle driving force control device (hereinafter referred to as “conventional technology”) disclosed in Patent Document 1. According to the prior art, in a hybrid vehicle, the engine operating state is controlled based on a preset optimum fuel consumption line, so that the fuel consumption rate is minimized according to the target engine speed. It is said that the engine torque can be obtained.

  For hybrid vehicles, we also propose a technology that obtains the operating point that is the optimum efficiency point from the engine characteristic map stored in advance for the drive power requirement value, and controls the throttle opening so that this operating point is maintained. (For example, refer to Patent Document 2).

  Further, in a hybrid vehicle, a technique for controlling the operation state of the internal combustion engine and the electric motor so as to minimize the fuel consumption rate of the engine in the entire operation region based on the power consumption and the storage state is proposed (for example, (See Patent Document 3).

  Furthermore, in a diesel engine, a technique for calculating an instantaneous fuel consumption rate from a fuel injection amount and a travel distance has been proposed (see, for example, Patent Document 4 or 5).

JP 2000-179371 A JP-A-10-98803 JP 2002-171604 A JP-A-8-334052 JP-A-8-334051

  The optimum fuel consumption line in an internal combustion engine varies depending on environmental conditions such as atmospheric pressure and humidity. However, since such changes are not taken into account in the conventional technology, even if the internal combustion engine is operated so as to minimize the fuel consumption rate based on the preset optimum fuel consumption line, the efficiency is relatively low. It may deteriorate and waste fuel.

  On the other hand, even if the optimal fuel consumption line is correct, if there is a point where the efficiency of the internal combustion engine is locally low among the points on the optimal fuel consumption line, operating the internal combustion engine at that point, Since the efficiency is originally a poor region, fuel may be wasted.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an internal combustion engine control apparatus and method for a hybrid vehicle that can efficiently operate the internal combustion engine in the hybrid vehicle.

  In order to solve the above-described problems, an internal combustion engine control apparatus for a hybrid vehicle according to the present invention is an internal combustion engine control apparatus for a hybrid vehicle that controls the internal combustion engine in a hybrid vehicle including a motor generator and an internal combustion engine as power sources. Then, based on the torque specifying means for specifying the torque of the internal combustion engine, the specified torque, the rotational speed of the internal combustion engine, and the fuel injection amount in the internal combustion engine, an instantaneous fuel consumption rate in the internal combustion engine is obtained. Based on the calculated fuel consumption rate calculating means and the calculated fuel consumption rate, the operation line set in advance on the coordinate plane having the torque and the rotation speed as the first axis and the second axis, respectively, is updated. Operating line updating means for performing, operating point setting means for setting the operating point of the internal combustion engine on the operating line, and setting the operating state of the internal combustion engine Control means for controlling according to the operating point, wherein the operating point setting means is a region where the point on the operating line to be set as the operating point is locally low on the operating line (I) a first setting process for setting the point to be set as the operating point, and (ii) a point to be set in a predetermined range including the point to be set on the operating line. On the other hand, the required output is maintained at the first operating point selected from the first region on the low output side and the second operating point selected from the second region on the high output side with respect to the point to be set. Among the second setting processes that are alternately set as the operating point, the process with the higher efficiency is performed.

  The motor generator according to the present invention converts electric energy supplied from a battery into mechanical energy to function as an electric motor, and generates electric power for supplying electric power to, for example, a battery by converting mechanical energy into electric energy. And function as a machine. Two types of motor generators may be installed in advance: a motor generator mainly used as an electric motor (motor) and a motor generator mainly used as a generator (generator). In the hybrid vehicle according to the present invention including such an internal combustion engine and a motor generator, so-called parallel control is suitably performed in which the motor generator can appropriately assist the power of the internal combustion engine.

  The “internal combustion engine” in the present invention is a general term for engines that convert combustion of fuel into motive power, but preferably refers to engines that use gasoline, diesel, LPG, or the like as fuel.

  An operating line is set in advance for the internal combustion engine. In the present invention, the operating point setting means sets the operating point of the internal combustion engine on the operating line, and the control means controls the operating state of the internal combustion engine to a state defined by the set operating point. Here, the “operation line” in the present invention is a line that defines the operation state of the internal combustion engine on a coordinate plane having the torque of the internal combustion engine and the rotational speed of the internal combustion engine as the first axis and the second axis, respectively. The line is defined by a plurality of operating points set in advance in association with the output value of the internal combustion engine, and preferably represents a line obtained by connecting the plurality of operating points. The individual operating points that define the operating line are preferably such that the fuel consumption rate (hereinafter referred to as “fuel consumption rate” as appropriate) is minimized at the output values of the internal combustion engines that are in a corresponding relationship, that is, the efficiency is maximum. Is set as a point representing the combination of torque and rotational speed (minimum operating point of fuel efficiency). Usually, the operating point setting means sets the operating point corresponding to the output required for the internal combustion engine as the operating point on this operating line (that is, preferably from a plurality of operating points).

  Here, in particular, the fuel efficiency minimum operating point slightly or clearly changes depending on, for example, atmospheric pressure, humidity, or fuel properties of the internal combustion engine. Accordingly, when the operation line is a fixed operation line set in advance as in the prior art, the internal combustion engine may be used at an operating point where the fuel consumption rate is not minimized.

  Therefore, according to the internal combustion engine control apparatus for a hybrid vehicle according to the present invention (hereinafter referred to as “internal combustion engine control apparatus” as appropriate), the operation line can be updated as described below. That is, according to the internal combustion engine control apparatus of the present invention, during the operation, the torque of the internal combustion engine is first specified by the torque specifying means. Further, the instantaneous fuel consumption rate of the internal combustion engine is calculated by the fuel consumption rate calculation means based on the specified torque, the rotational speed of the internal combustion engine, and the fuel injection amount of the internal combustion engine.

  The “torque specifying means” in the present invention may have, for example, a mode in which the torque of the internal combustion engine is measured or detected directly or indirectly, and the measured or detected torque is simply used as an electrical signal. The torque may be obtained numerically, or the torque may be obtained from any physical quantity, electrical quantity, or chemical quantity that is directly or indirectly measured or detected and related to the torque or torque. It may have a mode of calculating numerically, and the mode may be freely determined as long as the torque of the internal combustion engine can be finally specified. When measuring or detecting the torque directly or indirectly, for example, a known contact type or non-contact type torque sensor may be used. In the case where the hybrid vehicle is configured to be able to detect the torque of the internal combustion engine in a form called a so-called torque reaction force by a motor generator provided in the hybrid vehicle, a torque sensor or the like is provided separately. It is not necessary and is extremely efficient.

  The “fuel consumption rate” in the present invention is an index value representing the fuel injection amount per unit electric energy (for example, the unit is kWh) in the internal combustion engine. Further, “efficiency (or simply efficiency) of the internal combustion engine” in the present invention is the reciprocal of this fuel consumption rate, and is an index value representing the amount of electric power per unit fuel injection amount. Therefore, “effective” means that the fuel consumption rate is relatively small.

  Note that the output (ie, electric power) of the internal combustion engine is proportional to the product of the torque and the rotational speed of the internal combustion engine. In addition, “instantaneous” means that the fuel consumption rate can be calculated at a predetermined time or a predetermined time that is fixed or variable under a predetermined condition, or at any arbitrary time. It is the meaning that represents.

  The operation line update means according to the present invention is configured to be able to update the operation line based on the instantaneous fuel consumption rate obtained in this way. That is, the operation line (operation point) that has been fixed in the past can be freely set. At this time, the operation line may be updated in any way as long as the calculated fuel consumption rate is reflected. For example, the operation line is updated so that the fuel consumption rate at the operating point that defines the operation line is small. Is preferable. Since the operating point defines an operating line, the operating line is updated by updating the operating point. However, similarly, the operating line may be updated based on the instantaneous fuel consumption rate, and as a result, the operating point may be updated.

  As described above, the internal combustion engine control apparatus according to the present invention can operate the internal combustion engine efficiently by making the operation line updatable.

  Note that “updating the operation line” described here is not limited to simply changing the operation line, but also includes storing the changed operation line as needed. By storing the changed operation line in this way, it is possible to easily maintain the operation line in an optimum shape at all times. In addition, the fuel consumption rate for each operating point, which is a criterion for updating the operating line, is also stored in an appropriate form. Note that the efficiency of the internal combustion engine is naturally stored by storing the fuel consumption rate. By storing information on the operation line in this way, each means according to the present invention can refer to the fuel consumption rate or efficiency at each operation point at any time.

  Further, the period for storing the change of the operation line is not limited at all. For example, if the hybrid vehicle is not used for a certain period of time, the stored content may be erased and the operating point may return to the initial value set in advance again. In this case, the next time the hybrid vehicle is driven, the operation line is updated according to the situation at that time. On the other hand, the operation line may always be actively updated in a manner adapted to the use environment, purpose of use, or use frequency of the hybrid vehicle. That is, as long as the fuel consumption can be considerably reduced (improves efficiency) compared to the case where no operation line update is performed, the operation line update may be temporary. It may be permanent.

  In order to control the output of the internal combustion engine to the required output, the internal combustion engine may be controlled to a state defined by the operating point corresponding to the output required on the operating line where the appropriate update is performed. In the hybrid vehicle according to the invention, the required output can be obtained even if the internal combustion engine is operated at an operating point other than the operating point corresponding to the required output. For example, when the internal combustion engine is operated at an operating point on the output side lower than the required output, the motor generator is caused to function as an electric motor, or a motor generator set to function mainly as an electric motor is driven to operate the internal combustion engine. It is possible to assist the engine output, and when the internal combustion engine is operated at an operating point higher than the required output, the motor generator functions as a generator or mainly functions as a generator. The motor generator set to do so may be driven so that a part of the surplus output of the internal combustion engine is used for charging the battery.

  However, the time during which one of the controls can be continuously executed is limited, regardless of whether the motor generator assists or charges, and preferably the battery is charged by appropriately switching between these two operating points. The required output is maintained while discharging. In this case, due to the energy loss caused by alternately switching between charging and discharging, the efficiency of the internal combustion engine will eventually be lower than operating the internal combustion engine at the operating point corresponding to the output required on the operating line. There are many. Therefore, from the viewpoint of operating the internal combustion engine efficiently, it is preferable to operate the internal combustion engine at an operating point corresponding to the required output.

  On the other hand, the efficiency of the internal combustion engine at each operating point that defines the operating line is not uniform. In most cases, the efficiency decreases on the high output side of the internal combustion engine, but there may be a region where the efficiency of the internal combustion engine is locally low on the operating line, for example. Such a region is obtained when a curve (a kind of operation line) corresponding to the operation line is drawn on the coordinate plane having the efficiency of the internal combustion engine and the output of the internal combustion engine as the first axis and the second axis, respectively. However, when the internal combustion engine is operated at an operating point existing in such a region, the internal combustion engine is originally inefficient, so the internal combustion engine does not necessarily operate efficiently. It may not always be possible.

  Therefore, particularly in the internal combustion engine control apparatus according to the present invention, when the operating point setting means has a point on the operating line to be set as the operating point on the operating line and the efficiency of the internal combustion engine is locally low, Such a problem is solved by performing an efficient process of the first setting process and the second setting process.

  The first setting process is a process of setting an operating point to be set as an operating point as it is, for example, a process of setting an operating point corresponding to a required output as an operating point.

  The second setting process is a process of repeatedly charging and discharging the battery described above. In this case, the first operating point is selected from the first region on the low output side across the operating point to be set, and the high output side is selected. A second operating point is selected from the second region, and these operating points are alternately set as operating points so that the output required for the internal combustion engine is maintained. At this time, the first and second operating points are selected within a predetermined range including the operating points to be set. In this predetermined range, the first and second operating points are selected so that the internal combustion engine can be operated more efficiently than the operating point corresponding to the required output while maintaining the required output. This is set in advance as a possible range. The predetermined range may be determined by a technique such as experimental, empirical, or simulation. The first and second operating points are preferably the most efficient points in each of the first and second regions.

The first and second regions and the first and second operating points are of course defined on the operating line, but as long as the mutual relationship is known, as described above, from the operating line. It may be defined by another derived curve (a kind of operation line). The comparison of the efficiency of the internal combustion engine between the first setting process and the second setting process stores the fuel consumption rate at each operating point. Can be done easily. For example, the efficiency of the internal combustion engine when the second setting process is performed includes the fuel consumption rate (efficiency) at the first operating point, the fuel consumption rate (efficiency) at the second operating point, and the battery that supplies power to the motor generator. It is calculated based on the charging / discharging efficiency and the switching cycle of the first and second operating points. The switching cycle is determined by the difference between the outputs of the first and second operating points with respect to the point to be set as the operating point. For example, if the first operating point is located at a position farther away from the second operating point than the second operating point with respect to the point to be set, the time for operating the internal combustion engine at the first operating point is the second operating point. This is shorter than the time for operating the internal combustion engine. Such a difference in output corresponds to a difference in axis component corresponding to the output of each operating point in the coordinate plane with the efficiency and output of the internal combustion engine as axes.

  The shape of the operation line is always grasped by the operation point setting means when the operation line is updated or when the operation line is not updated. Therefore, the operating point setting means can easily determine in advance a point or a region on the operating line that can operate the internal combustion engine more efficiently when the second setting process is performed, which is extremely efficient. is there.

  As described above, the internal combustion engine control apparatus according to the present invention is a case where there is a locally inefficient region on the operation line because the instantaneous fuel consumption rate can be calculated and the operation line can be updated. However, the internal combustion engine can be operated efficiently.

  In one aspect of the internal combustion engine control apparatus for a hybrid vehicle according to the present invention, the predetermined range is defined based on charge / discharge characteristics of a battery that supplies power to the motor generator.

  According to this aspect, since the predetermined range for selecting the first and second operating points is defined based on the charge / discharge characteristics of the battery, the first and second operating points can be efficiently selected. It becomes possible.

  In another aspect of the internal combustion engine control apparatus for a hybrid vehicle according to the present invention, the operating point setting means uses the operating point with the highest efficiency in each of the first and second regions as the first and second operating points. select.

  According to this aspect, the operating point with the highest efficiency in each of the first and second regions is set as the first and second operating points. Therefore, the first setting process and the second setting process can be compared efficiently and effectively.

  In another aspect of the control apparatus for an internal combustion engine of a hybrid vehicle according to the present invention, the operating point setting means includes a period in which the speed of the hybrid vehicle is less than a predetermined speed and a period in which the output of the internal combustion engine is less than a predetermined output value. And prohibiting the second setting process.

  When the second setting process is performed, the rotational speed of the internal combustion engine changes periodically or randomly in order to repeatedly charge and discharge the battery. In this case, noise and vibration for the driver driving the hybrid vehicle are larger than when the internal combustion engine is operated only at the operating point corresponding to the required output. Furthermore, even if the driver intends to maintain the rotational speed by depressing a certain amount of the accelerator pedal, for example, the rotational speed frequently fluctuates, which may cause discomfort. Such a problem is remarkable when the hybrid vehicle is traveling at a low speed or when the internal combustion engine is operating at a low output.

  According to this aspect, since the second setting process is prohibited during a period in which the hybrid vehicle is traveling at a speed lower than the predetermined speed and a period in which the internal combustion engine is operating at a speed less than the predetermined output value, such a sense of incongruity is generated. Is prevented and comfort is improved.

  The predetermined speed and the predetermined output value may be set in advance according to the type and application of the hybrid vehicle, or may be configured to be selectable to some extent on the driver side. Further, these predetermined values may be given in advance values that can be considered appropriate through experimentation, experience, simulation, or the like.

  In order to solve the above-described problems, an internal combustion engine control apparatus for a hybrid vehicle according to the present invention is an internal combustion engine control apparatus for a hybrid vehicle that controls the internal combustion engine in a hybrid vehicle including a motor generator and an internal combustion engine as power sources. Then, based on the torque specifying means for specifying the torque of the internal combustion engine, the specified torque, the rotational speed of the internal combustion engine, and the fuel injection amount in the internal combustion engine, an instantaneous fuel consumption rate in the internal combustion engine is obtained. Based on the calculated fuel consumption rate calculating means and the calculated fuel consumption rate, the operation line set in advance on the coordinate plane having the torque and the rotation speed as the first axis and the second axis, respectively, is updated. Operating line updating means for performing, operating point setting means for setting the operating point of the internal combustion engine on the operating line, and setting the operating state of the internal combustion engine Control means for controlling according to the operating point, wherein the operating point setting means is a region where the point on the operating line to be set as the operating point is locally low on the operating line The first operation point selected from the first region on the low output side with respect to the point to be set in the predetermined range including the point to be set on the operation line and the point to be set. On the other hand, the second operating point selected from the second region on the high output side is alternately set as the operating point so that the required output is maintained.

  According to the internal combustion engine control device for another hybrid vehicle according to the present invention, the first setting process described above is not performed in a region where the efficiency of the internal combustion engine is locally bad on the operation line. That is, the above-described second setting process is positively performed in such a region. Therefore, it is possible to reduce the load necessary for comparing the efficiency.

  The internal combustion engine control device for another hybrid vehicle according to the present invention exclusively selects the second setting process or prohibits the first setting processing in the above-described hybrid vehicle internal combustion engine control device according to the present invention. It corresponds to the thing.

  In order to solve the above-described problems, an internal combustion engine control method for a hybrid vehicle according to the present invention is a hybrid vehicle internal combustion engine control method for controlling an internal combustion engine in a hybrid vehicle including a motor generator and an internal combustion engine as power sources. And determining the instantaneous fuel consumption rate in the internal combustion engine based on the specified torque, the rotational speed of the internal combustion engine, and the fuel injection amount in the internal combustion engine. Based on the calculated fuel consumption rate calculation step and the calculated fuel consumption rate, the operation line set in advance on the coordinate plane with the torque and the rotation speed as the first axis and the second axis, respectively, is updated. An operating line update step to be performed; an operating point setting step of setting an operating point of the internal combustion engine on the operating line; and an operating state of the internal combustion engine to be set A control step of controlling according to the operating point, wherein the operating point setting step is a region where the point on the operating line to be set as the operating point is locally low on the operating line (I) a first setting process for setting the point to be set as the operating point, and (ii) a point to be set in a predetermined range including the point to be set on the operating line. On the other hand, the required output is maintained at the first operating point selected from the first region on the low output side and the second operating point selected from the second region on the high output side with respect to the point to be set. Among the second setting processes that are alternately set as the operating point, the process with the higher efficiency is performed.

  According to the method for controlling an internal combustion engine of a hybrid vehicle according to the present invention, during the operation thereof, the internal combustion engine of the hybrid vehicle according to the present invention is performed by the respective steps for realizing the operation of the above-described internal combustion engine control device for the hybrid vehicle according to the present invention. It is possible to obtain the same effect as that of the control device.

  Such an operation and other advantages of the present invention will be clarified by embodiments described below.

Various preferred embodiments of the present invention will be described below with reference to the drawings.
<1: First Embodiment>
<1-1: Configuration of Embodiment>
<1-1-1: Configuration of hybrid system>
First, the configuration of the hybrid system 10 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram of the hybrid system 10.

  In FIG. 1, a hybrid system 10 includes a control device 100, an engine 200, a motor generator MG1, a motor generator MG2, a power split mechanism 300, an inverter 400, a battery 500, and a vehicle speed sensor 600, and is a system that controls the hybrid vehicle 20. is there.

  The control device 100 includes an operation state control unit 100a, a torque calculation unit 100b, a fuel consumption rate calculation unit 100c, an operation line update unit 100d, a storage unit 100e, and an operation point setting unit 100f, and controls the entire operation of the hybrid system 10. A control unit such as an ECU (Engine Controlling Unit), for example, and functions as an example of the “internal combustion engine control device for a hybrid vehicle” according to the present invention.

  The operation state control unit 100a is an example of the “control unit” according to the present invention configured to be able to control the operation states of the engine 200, the motor generator MG1, and the motor generator MG2.

  The torque calculation unit 100b is an example of the “torque specifying means” according to the present invention configured to be able to calculate the torque of the engine 200.

  The fuel consumption rate calculation unit 100c is an example of the “fuel consumption rate calculation unit” according to the present invention configured to be able to calculate the fuel consumption rate of the engine 200.

  The operation line update unit 100d is configured to be able to execute an operation point learning process as an example of “update of operation line” according to the present invention, according to the control program stored in the storage unit 100e. It is an example of “operation line update means”. The operating point learning process will be described later.

  The storage unit 100e is a storage medium having a non-volatile storage area configured with, for example, a ROM (Read Only Memory) and a volatile storage area configured with a RAM (Random Access Memory). In the storage unit 100e, various predetermined control programs, a control map described later, and the like are stored in the nonvolatile area. In the volatile area, a learning result when an operation point learning process described later is performed is appropriately stored.

  The operating point setting unit 100f is an example of the “operating point setting unit” according to the present invention configured to be able to set the operating point of the engine 200, and according to the operating point set by the operating point setting unit 100f, The operation state control unit 100 a can control the operation state of the engine 200.

  The engine 200 is a gasoline engine as an example of the “internal combustion engine” according to the present invention, and functions as a main power source of the hybrid vehicle 20. The detailed configuration of the engine 200 will be described later.

  Motor generator MG1 is an example of the “motor generator” according to the present invention, and is configured to function as a generator for charging battery 500 or as an electric motor for assisting the driving force of engine 200.

  Motor generator MG2 is another example of the “motor generator” according to the present invention, and is configured to function as an electric motor for assisting the output of engine 200 or as a generator for charging battery 500.

  The motor generator MG1 and the motor generator MG2 are configured as, for example, a synchronous motor generator, and include a rotor having a plurality of permanent magnets on the outer peripheral surface, and a stator wound with a three-phase coil that forms a rotating magnetic field. Prepare. However, other types of motor generators may be used.

  The power split mechanism 300 is a planetary gear mechanism including a sun gear, a planetary carrier, a pinion gear, and a ring gear (not shown). Among these gears, the rotation shaft of the sun gear on the inner periphery is connected to the motor generator MG1, and the rotation shaft of the ring gear on the outer periphery is connected to the motor generator MG2. The rotation shaft of the planetary carrier located between the sun gear and the ring gear is connected to the engine 200, and the rotation of the engine 200 is transmitted to the sun gear and the ring gear by the planetary carrier and further the pinion gear. Is configured to be divided into two systems. In the hybrid vehicle 20, the rotating shaft of the ring gear is connected to the transmission mechanism 21 in the hybrid vehicle 20, and the driving force is transmitted to the wheels 22 through the transmission mechanism 21.

  Inverter 400 converts DC power extracted from battery 500 into AC power and supplies it to motor generator MG1 and motor generator MG2, and also converts AC power generated by motor generator MG1 and motor generator MG2 into DC power. The battery 500 can be supplied.

  The battery 500 is a rechargeable storage battery configured to be able to function as a power source for driving the motor generator MG1 and the motor generator MG2. The battery 500 is provided with an SOC sensor 510 that detects the remaining capacity of the battery 500 and is electrically connected to the control device 100.

  The vehicle speed sensor 600 is a sensor that detects the speed of the hybrid vehicle 20 and is electrically connected to the control device 100.

<1-1-2: Detailed configuration of engine>
Next, with reference to FIG. 2, the detailed configuration of the engine 200 will be described together with its basic operation. FIG. 2 is a half sectional system diagram of the engine 200.

  In FIG. 2, the engine 200 causes the air-fuel mixture to explode in the cylinder 201 by the spark plug 202 and converts the reciprocating motion of the piston 203 generated according to the explosive force into the rotational motion of the crankshaft 205 via the connection rod 204. It is configured to be able to. Below, the principal part structure of the engine 200 is demonstrated.

  When the fuel is burned in the cylinder 201, the air sucked from the outside passes through the intake pipe 206 and is mixed with the fuel injected from the injector 207 to become the above-mentioned air-fuel mixture. Fuel (gasoline) is supplied to the injector 207 from the fuel tank 223 via the filter 224, and the injector 207 can inject the supplied fuel into the intake pipe 206 in accordance with control of the control device 100. It is configured to be possible. The fuel tank 223 is provided with a fuel sensor 225 for detecting the remaining amount of fuel.

  The communication state between the inside of the cylinder 201 and the intake pipe 206 is controlled by opening and closing the intake valve 208. The air-fuel mixture burned in the cylinder 201 becomes exhaust gas, passes through the exhaust valve 209 that opens and closes in conjunction with opening and closing of the intake valve 208, and is exhausted through the exhaust pipe 210.

  A cleaner 211 is disposed on the intake pipe 206 to purify air sucked from the outside. An air flow meter 212 is disposed on the downstream side (cylinder side) of the cleaner 211. The air flow meter 212 has a form called a hot wire type, and is configured to be able to directly measure the mass flow rate of the inhaled air. The intake pipe 206 is further provided with an intake air temperature sensor 213 for detecting the temperature of the intake air.

  A throttle valve 214 that adjusts the amount of intake air into the cylinder 201 is disposed downstream of the air flow meter 212 in the intake pipe 206. A throttle position sensor 215 is electrically connected to the throttle valve 214, and its opening degree can be detected. Further, an accelerator position sensor 216 that detects the amount of depression of the accelerator pedal 226 by the driver and a throttle valve motor 217 that drives the throttle valve 214 are also provided around the throttle valve 214.

  A crank position sensor 218 that detects the rotational position of the crankshaft 205 is provided in the vicinity of the crankshaft 205. The crank position sensor 218 is a sensor configured to be able to detect the position of the crankshaft 205, and the control unit 100 determines the position of the piston 203 and the rotational speed of the engine 200 based on the output signal of the crank position sensor 218. Etc. are configured to be able to obtain. The position of the piston 203 is used for controlling the ignition timing in the spark plug 202 described above. The ignition timing in the spark plug 202 is, for example, retarded or advanced with respect to a preset basic value associated with the position of the piston 203.

  Further, a knock sensor 219 capable of measuring the knock strength of the engine 200 is disposed in the cylinder block that accommodates the cylinder 201, and the cooling water of the engine 200 is placed in the water jacket in the cylinder block. A water temperature sensor 220 for detecting the temperature is provided.

  A three-way catalyst 222 is installed in the exhaust pipe 210. The three-way catalyst 222 is a catalyst capable of purifying CO (carbon monoxide), HC (hydrocarbon), and NOx (nitrogen oxide) discharged from the engine 200, respectively. An air-fuel ratio sensor 221 is disposed upstream of the three-way catalyst 222 in the exhaust pipe 210. The air-fuel ratio sensor 221 is configured to be able to detect the air-fuel ratio of the engine 200 from the exhaust gas discharged from the exhaust pipe 210.

<1-2: Operation of Embodiment>
<1-2-1: Basic operation of hybrid system>
In the hybrid system 10 of FIG. 1, the driving force distribution among the motor generator MG1 that mainly functions as a generator, the motor generator MG2 that mainly functions as an electric motor, and the engine 200 is an operation state control unit 100a and a power split mechanism 300. To control the traveling state of the hybrid vehicle 20. Below, operation | movement of the hybrid system 10 according to several situations is demonstrated.

<1-2-1: At start-up>
For example, when hybrid vehicle 20 is started, motor generator MG1 driven using the electric energy of battery 500 functions as an electric motor. With this power, the engine 200 is cranked and the engine 200 is started.

<1-2-1-2: When starting>
At the time of departure, two types of modes can be adopted depending on the storage state of the battery 500. The storage state of the battery 500 is grasped by the operation state control unit 100a based on the output signal of the SOC sensor 510. For example, during a normal start (that is, with a good SOC), it is not necessary to charge the battery 500 by the motor generator MG1, so the engine 200 is started only for warm-up, and the hybrid vehicle 20 The vehicle starts with the driving force of the generator MG2. On the other hand, when the state of charge is not good (that is, the SOC is lowered), motor generator MG1 functions as a generator by the power of engine 200, and battery 500 is charged.

<1-2-1-3: During light load driving>
For example, when the vehicle is traveling at a low speed or on a gentle hill, the efficiency of the engine 200 is relatively poor, so the engine 200 is stopped and the hybrid vehicle 20 travels only with the driving force of the motor generator MG2. At this time, if the SOC is lowered, engine 200 starts to drive motor generator MG1, and battery 500 is charged by motor generator MG1.

<1-2-1-4: During normal driving>
In an operating region where the efficiency of the engine 200 is relatively good, the hybrid vehicle 20 travels mainly by the power of the engine 200. At this time, the power of the engine 200 is divided into two systems by the power split mechanism 300, one is transmitted to the wheels 22 via the transmission mechanism 21, and the other is driven by the motor generator MG1 to generate power. Furthermore, motor generator MG2 is driven by the generated electric power, and the power of engine 200 is assisted by motor generator MG2. At this time, if the SOC is lowered, the output of engine 200 is increased, and a part of the electric power generated by motor generator MG1 is charged to battery 500.

<1-2-1-5: During braking>
When deceleration is performed, the motor generator MG2 is rotated by the power transmitted from the wheels 22 to operate as a generator. Thereby, the kinetic energy of the wheel 22 is converted into electric energy, and so-called “regeneration” is performed in which the battery 500 is charged.

<1-2-2: Basic Control Operation of Engine in Embodiment>
Next, a basic control operation of the engine 200 will be described.

  The operation state control unit 100a repeatedly calculates an engine request output, which is an output required for the engine 200, at a constant cycle. The operating state control unit 100a acquires the accelerator opening and the vehicle speed based on the output signals of the throttle position sensor 215 and the vehicle speed sensor 600, and refers to the map recorded in the non-volatile area of the storage unit 100e. The output shaft torque corresponding to the vehicle speed (torque to be output to the transmission mechanism 21) is obtained. Further, the operation state control unit 100a obtains the required power generation amount based on the output signal of the SOC sensor 510. The engine required output is obtained by correcting the output shaft torque with reference to the required power generation amount and the required amounts of various auxiliary machines (A / C, power steering, etc.). It should be noted that the calculation method of the engine required output may be as executed in a known hybrid vehicle, and the details thereof may be variously changed as necessary.

<1-2-3: Operating point learning process>
<1-2-3-1: Operation line and operation point>
Next, with reference to FIG. 3, an operation line and an operation point according to the operation point learning process of the present invention will be described. FIG. 3 is a schematic diagram of the control map 30.

  In FIG. 3, the control map 30 includes a torque Te of the engine 200 on the vertical axis (that is, an example of the “first axis” according to the present invention), and a horizontal axis (that is, an example of the “second axis” according to the present invention). Is a coordinate plane representing the rotational speed Ne of the engine 200, and is an example of the “coordinate plane” according to the present invention. The control map 30 is stored in advance in a non-volatile area in the storage unit 100e of the control device 100.

  On the control map 30, it is possible to represent the relationship between the engine torque Te and the engine speed Ne for various parameters. Among these, the equal output line Pi (i = 1, 2,..., 9) is a relationship line between the engine torque Te and the engine speed Ne when the output value of the engine 200 is constant. In the present embodiment, the output of the engine 200 corresponding to the equal output line Pi is referred to as “output Pi” as appropriate. In FIG. 3, only nine equal output lines are drawn for simplification of explanation, but in actuality, it can be set more finely.

  When the engine 200 is operated, an operating point is set by the operating point setting unit 100f. Normally, the operating point setting unit 100f sets the operating point set in advance on the iso-output line corresponding to the required output value obtained each time as the operating point of the engine 200. The operation state control unit 100a determines the operation state of the engine 200 so as to be a combination of the engine torque Te and the engine speed Ne represented by the set operation point. The operation line according to the present embodiment is defined as connecting these preset operation points.

  In FIG. 3, an operation line Q is an operation line set as an initial value, and is defined by an operation point Qi (i = 1, 2,..., 9) corresponding to the equal output line Pi. On each iso-output line, the operating point Qi is set in advance to the point where the fuel consumption rate is minimum (that is, the highest efficiency), and is optimal under standard environmental conditions at the time of factory shipment, for example. It has become.

  However, since the usage conditions of the hybrid vehicle 20 cannot be uniform, when the engine 200 is operated at the preset operating point as described above, the fuel consumption rate of the engine 200 is not necessarily the minimum. . This is because the distribution of the equal fuel consumption rate line S representing the region where the fuel consumption rates are equal on the control map 30 changes according to the environmental conditions and control conditions of the engine 200. As a result of the change in the distribution of the equal fuel consumption rate line S, for example, the operating point on each iso-output line Pi changes to the operating point Ri (i = 1, 2,..., 9). As a result, the operating line of engine 200 changes to operating line R.

  In order to cope with such a situation where the operating point at which the fuel consumption rate becomes the minimum changes according to various conditions, in the hybrid system 10 according to the present embodiment, the operating point learning process is performed by the operating line update unit 100d. Is done. By this operating point learning process, the hybrid system 10 can always operate the engine 200 efficiently.

<1-2-3-2: Overview of the operating point learning process>
The operating point learning process according to the present embodiment includes the following steps (1) to (3).

  (1) A step of changing the operating point of the engine 200 on the equal output line Pi.

  (2) A step of calculating a fuel consumption rate at each of the changed operating points.

  (3) A step of determining an operating point with the lowest fuel consumption rate (minimum operating rate of fuel consumption rate) and resetting (i.e., updating) the operating point on the iso-output line Pi.

  In the present embodiment, the operation state control unit 100a copies the control map 30 from the non-volatile area of the storage unit 100e to the volatile area, and controls the engine 200 using the copied control map 30. Yes. The operating point learning process is a process for appropriately rewriting the control map 30 on this volatile area. By performing the steps (1) to (3), the operating point when operating the engine 200 on one iso-output line Pi is updated to the fuel efficiency minimum operating point. Therefore, the engine 200 can continue to maintain a relatively efficient state or a most efficient state. In the present embodiment, once the operating point learning process is performed, the operating point update result is stored until the battery 500 is reset in the engine 200. However, the time range in which the operating point learning process is effective is not limited to the above. For example, in response to a driver's request or whenever the engine 200 is stopped, the operation line is reset and returned to an initial state (a state defined by the control map 30 stored in the non-volatile area of the storage unit 100e). May be.

<1-2-3-3: Details of the operating point learning process>
Next, the details of the operating point learning process according to the present embodiment will be described with reference to FIG. FIG. 4 is a flowchart of the operating point learning process.

  In FIG. 4, for example, during normal traveling of the hybrid vehicle 20, the operation line update unit 100 d sets the operation point of the engine 200 to be an operation point to be compared on the current equal output line Pi (step A <b> 11). . Specifically, the operating line update unit 100d controls the operating point setting unit 100f so that the operating point of the engine 200 is set to the operating point. In response to this, the control state of engine 200 is controlled by operation state control unit 100a to an operation state defined by the set operation point. Here, the “operating point to be compared” refers to one of the operating points to be compared with the fuel consumption rate for performing the operating point learning process. In step A11 that is first visited after the operation point learning process is started, the operation point set as the operation point on the iso-output line Pi at that time (that is, the updated value or the initial value Qi by the previous operation point learning process). ) Is set as the operating point.

  Next, the fuel consumption rate calculation unit 100c calculates the fuel consumption rate of the engine 200 at the set operating point (step A12). The fuel consumption rate is a fuel injection amount per unit power amount of the engine 200. Therefore, this is equivalent to the fuel injection amount of the injector 207 divided by the electric energy (kWh) calculated from the output value (kW) of the engine 200.

  The fuel injection amount is further varied with respect to the basic injection amount determined by the operating state control unit 100a based on the basic injection amount map stored in the nonvolatile region of the storage unit 100e from the rotation speed and load factor of the engine 200. Obtained as a result of correction. The fuel consumption rate calculation unit 100c acquires the fuel injection amount from the operation state control unit 100a.

  On the other hand, torque calculation unit 100b calculates the torque of engine 200 from the torque reaction force of engine 200 detected via motor generator MG1. The fuel consumption rate calculation unit 100c acquires the calculated torque, acquires the rotation speed of the engine 200 calculated based on the output value of the crank position sensor 218 from the operation state control unit 100a, and uses these values. The output of the engine 200 is calculated.

  The fuel consumption rate calculation unit 100c calculates the fuel consumption rate at the currently set operating point based on the fuel injection amount in the engine 200 and the output of the engine 200.

  When the fuel consumption rate is calculated for one operating point, the operation line update unit 100d determines whether or not the minimum fuel consumption rate operating point has been determined (step A13).

  This determination is made based on a determination criterion given in advance by experimentation, experience, simulation, or the like. For example, when the operating point is moved in a certain direction on the equal output line, the fuel consumption rate gradually decreases, and when the operating point gradually increases with a certain operating point as a boundary, the equal fuel consumption rate line S in FIG. Even if it says from this shape, you may consider the operating point concerned as a fuel consumption rate minimum operating point.

  Therefore, the determination according to step A13 should be determined from the context of the calculated value of the fuel consumption rate rather than clearly determining the magnitude relationship compared to some threshold value. The embodiments are different. However, in the process related to step A13 that is first visited after the start of the operating point learning process, there is no comparison target, so the conditional branch is “NO”.

  When the fuel efficiency minimum operating point is not fixed (step A13: NO), the operation line update unit 100d returns the process to step A11, and performs the processing from step A11 to step A13 until the fuel efficiency minimum operating point is determined. repeat.

  At this time, the operating points set in step A11 may be, for example, discrete operating points on the iso-output line, that is, operating points that are appropriately separated, or continuous, that is, operating points that are very close to each other. It may be. The method of changing these operating points may be given in advance, for example, experimentally, empirically, or by simulation, and the operating line update unit 100d learns the operating point each time. It may be determined in view of the progress of processing.

  As a result of repeating such a process, when the fuel efficiency minimum operation point is determined (step A13: YES), the operation line update unit 100d updates the operation point (step A14). At this time, in the control map 30 copied to the volatile area, the operating point on the iso-output line on which the operating point learning process has been performed is rewritten, and the operating line changes accordingly. When the operating point and the operating line are updated, update information is stored (step A15). The update information in the present embodiment refers to information representing the fuel consumption rate and efficiency for all operating points on the updated operating line. The update information is stored in the volatile area in the storage unit 100e in association with the output values of the engine 200 corresponding to these operating points. When the update information is stored, the operating point learning process ends.

  As described above, in the hybrid system 10, the operating line update unit 100d performs the operating point learning process so that the operating point of the engine 200 is set to the point where the fuel consumption rate is minimized even when the hybrid vehicle 20 is traveling. The engine 200 can be operated efficiently and easily.

<1-2-4: Setting of operating point>
When the operating point is set on the operating line, the operating point setting unit 100f sets the operating point corresponding to the engine required output as the operating point on the operating line represented in the control map 30. From the viewpoint of operating the engine 200 efficiently, in most cases, it is preferable to operate the engine 200 at an operating point corresponding to the required output. However, this may not occur depending on the characteristics of the engine 200, the application, or changes over time.

  Here, the efficiency of the engine 200 will be described with reference to FIG. FIG. 5 is a schematic diagram of the control map 31.

  In FIG. 5, the control map 31 is a coordinate plane in which the vertical axis represents the efficiency ηe of the engine 200 and the horizontal axis represents the output Pe of the engine 200. On the control map 31, a curve corresponding to the operation line represented on the control map 30 is drawn. In the present embodiment, the curve on the control map 31 is also referred to as an “operation line” as appropriate, and each point on the control map 31 (that is, the operation point) is paired with each operation point on the control map 30. It shall correspond to one. Therefore, the operating point indicated by one operating line is the operating point on the other operating line at the same time. The control map 31 is stored in a non-volatile area of the storage unit 100e, and, like the control map 30, is copied to a volatile area of the storage unit 100e and then updated along with the update of the operation line.

  In FIG. 5, a part of the operation line on the control map 31 is locally depressed (see “comparison target area” in the figure). When the operating point corresponding to the requested output (that is, the “operating point to be set” according to the present invention) exists in such a region where the efficiency has dropped, the other operating points are set so that the requested output is maintained. It may be possible to operate the engine 200 with higher efficiency by alternately switching and setting the operating point. The control map 31 can visually represent a region where such efficiency is locally low. However, in the control map 30, such a local change in efficiency appears as the shape of the operation line. Absent. However, since the engine efficiency for the operating point is stored in the storage unit 100e, such a region where the engine efficiency is locally low can be identified on the control map 30 as well.

  In the present embodiment, the operating point setting unit 100f is configured to be able to perform two types of processes, a first setting process and a second setting process, when setting an operating point. The first setting process is a process for setting the operating point to be set as an operating point as it is, and the second setting process is an operation in which other operating points are alternately switched so that the required output is maintained. Refers to processing set as a point.

  Here, the second setting process will be described with reference to FIG.

  Now, it is assumed that the operation point to be set is the operation point V1 existing in the comparison target region. In this case, within the battery input / output restriction range defined by the charge / discharge characteristics of the battery 500 with the operating point V1 as the center, the first region that is on the lower output side than the operating point V1 and the high output side. From the second region, the highest efficiency point is selected and set as the operating point. In FIG. 5, the operating point V2 from the first region and the operating point V3 from the second region are set as the operating points, respectively.

  The operating point setting unit 100f alternately switches the two operating points set in this way so that the requested output is maintained. However, the distance between the operating point V2 and the operating point V3 (that is, the difference in output) with respect to the operating point V1 to be set is different from each other, and therefore the ratio of the period set as the operating point is not necessarily 1: 1. In FIG. 5, since the operating point V2 is farther away, the period during which the operating point V2 is set as the operating point is shorter than that of the operating point V3. In this way, the second setting process is performed. The operation state control unit 100a controls the operation state of the engine 200 according to the operation point set in this way.

  In the present embodiment, the information on the operating point (for example, the operating point V2 and the operating point V3 in FIG. 5) for performing such a second setting process is either the second setting process or the first setting process. This information is stored in advance in the volatile area of the storage unit 100e together with information on whether the engine 200 can be operated more efficiently. More specifically, these pieces of information are stored when the operating point setting unit 100f performs a setting selection process described below.

  Here, the setting selection processing will be described with reference to FIG. FIG. 6 is a flowchart of the setting selection process.

  In FIG. 6, the operating point setting unit 100f determines whether or not a comparison target region exists on the operation line in the control map 31 existing in the volatile region of the storage unit 100e at the present time (step B11). The determination as to whether or not the region is a comparison target region may be performed based on a clear determination criterion such as a threshold value, and if the determination is made on the control map 31, the geometric feature (operation line Based on the shape). In the present embodiment, the efficiency of the engine 200 is embodied as an operation line of the control map 31 including the meaning of making the explanation easy to understand. However, all the engine efficiencies at the individual operation points are stored in the storage unit 100e. Therefore, the operating point setting unit 100f may perform these processes on the control map 30.

  When it is determined that there is no comparison target area (step B11: NO), the setting selection process ends. When it is determined that there is a comparison target area (step B11: YES), the operating point setting unit 100f determines whether the comparison target area is outside the prohibited area (step B12).

  The “prohibited area” in the present embodiment is an area where the second setting process is prohibited, and refers to an area where the output of the engine 200 is less than a predetermined value. The output threshold is determined in advance as a value that does not give the driver an uncomfortable feeling experimentally, empirically, or by simulation. If the comparison target area is a prohibited area (step B12: NO), the setting selection process ends. At this time, if a part of the comparison target area is outside the prohibited area, the process is continued for the part outside the prohibited area.

  When the comparison target area is outside the prohibited area (step B12: YES), the operating point for the first setting process (for example, the operating point V1 in FIG. 5) is selected from the comparison target area (step B13). When the operating point for the first setting process is selected, the operating points for the second setting process (for example, the operating point V2 and the operating point V3 in FIG. 5) are subsequently selected (step B14). As the operating point for the second setting process, the operating point with the highest efficiency of the engine 200 is selected from the first and second regions in FIG.

  When the operating point for the first setting process and the operating point for the second setting process are selected, the engine efficiency η1 when the first setting process is used and the engine efficiency η2 when the second setting process is performed Are respectively calculated and it is determined whether or not the engine efficiency η2 is larger than the engine efficiency η1 (step B15).

  Here, the engine efficiency η1 is the efficiency at the operating point V1 stored in the volatile area of the storage unit 100e. The engine efficiency η2 is calculated based on the efficiency at the operating point V2 and the operating point V3 stored in the volatile area of the storage unit 100e, the switching cycle of these operating points, and the charge / discharge efficiency of the battery 500. The charge / discharge efficiency is the ratio of the power that can be discharged to the charged power.

  As a result of the comparison, when the engine efficiency η1 is equal to or higher than the engine efficiency η2 (step B15: NO), the operating point setting unit 100f shifts the processing to step B17 without performing any processing. When the engine efficiency η2 is larger (step B15: YES), the operating point for the first setting process at the present time is stored in the storage unit 100e as the second setting process priority operating point (step B16). At this time, the operation point for the second setting process corresponding to the stored operation point for the first setting process is also stored together with various information such as the switching period in the second setting process.

  When the engine efficiency η1 is equal to or higher than the engine efficiency η2 or the second setting process priority operation point is stored, it is determined whether or not there is an operation point that has not been compared with the engine efficiency in the comparison target region (step B17). ). If there is an uncompared operating point (step B17: YES), the process returns to step B13 again, and the loop processing from step B13 to step B17 is repeated. The engine efficiency is compared for all the operating points in the comparison target area, and when there are no uncompared operating points in the comparison target area (step B17: NO), the setting selection process ends.

  The operating point setting unit 100f performs the setting selection process every time the operating line update unit 100d executes the operating point learning process or whenever the operating line is updated. However, the operating point setting unit 100f may perform these processes in anticipation of a relatively light processing load.

  The operating point setting unit 100f sets the operating point of the engine 200 based on the result of the setting selection process described above. Here, with reference to FIG. 7, the operating point setting process by the operating point setting unit 100f will be described. FIG. 7 is a flowchart of the operating point setting process.

  In FIG. 7, first, the operating point setting unit 100f acquires the current speed of the hybrid vehicle 20 from the output of the vehicle speed sensor 600, and determines whether or not the speed is less than a predetermined speed (step C11). . In the present embodiment, the operating point setting unit 100f does not perform the second setting process when the hybrid vehicle 20 is traveling at a low speed. This is to prevent the driver from feeling uncomfortable as in the engine low output region described above. Therefore, the predetermined speed is also experimentally, empirically, or Appropriate values are given by techniques such as simulation.

  When the vehicle speed is less than the predetermined speed (step C11: YES), the operating point setting unit 100f unconditionally executes the first setting process (step C14). On the other hand, if the vehicle speed is equal to or higher than the predetermined speed (step C11: NO), whether or not the operating point corresponding to the required output to the engine 200 (that is, the operating point to be set) is the second setting processing priority operating point. Is determined (step C12). Information regarding whether or not it is the second setting process priority operation point is stored in advance in the storage unit 100e by the setting selection process, and the operation point setting unit 100f refers to this stored content and quickly performs the determination. Is possible. In the setting selection process described above, if it is determined that the comparison target area does not exist or is present in the low output area of the engine 200, the processes related to step C11 and step C12 are skipped, Step C14 may be performed unconditionally. In this case, that is, the operating point is set in the same manner as the normal operating point is set.

  When the operating point to be set is not the second setting process priority operating point (step C12: NO), the operating point setting unit 100f sets the operating point according to the first setting process (step C14). On the other hand, when it is the second setting process priority operation point (step C12: YES), the operation point is set according to the second setting process (step C13). At this time, information on the operation point for the second setting process corresponding to the operation point to be set is acquired from the storage unit 100e, and based on this information, the two operation points are alternately set as the operation point at an appropriate cycle. Is set. When the operating point is set by the first setting process or the second setting process, the operating point setting process ends.

  As described above, according to the hybrid system 10 according to the present embodiment, the operation point setting unit 100f always performs the setting selection process and the operation point setting process based on the updated operation line. The engine 200 can be operated efficiently.

  In the setting selection process described above, the engine setting is not compared in the first setting process and the second setting process, and the second setting process is unconditionally performed on the operating point existing in the comparison target region. It may be broken. At this time, whether or not the comparison is necessary may be determined according to the degree of decrease in engine efficiency in the comparison target region. Further, when it is predicted experimentally, empirically, or by simulation or the like that the second setting process can operate the engine 200 more efficiently without performing such comparison, The necessity for comparison may be determined based on the prediction. In the case where comparison is not performed, for example, processing in which Step B13 and Step B15 are skipped in FIG. 6 is performed.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. Engine control devices and methods are also within the scope of the present invention.

1 is a block diagram of a hybrid system according to a first embodiment of the present invention. FIG. 2 is a half sectional system diagram of an engine in the hybrid system of FIG. 1. It is a schematic diagram of the control map in the hybrid system of FIG. It is a flowchart of the operating point learning process in the hybrid system of FIG. It is a schematic diagram of the other control map in the hybrid system of FIG. It is a flowchart of the setting selection process in the hybrid system of FIG. It is a flowchart of the operating point setting process in the hybrid system of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Hybrid system, 11 ... Hybrid system, 20 ... Hybrid vehicle, 21 ... Transmission mechanism, 22 ... Wheel, 30 ... Control map, 31 ... Control map, 100 ... Control apparatus, 200 ... Engine, MG1 ... Motor generator, MG2 ... Motor generator, 300 ... power split mechanism, 400 ... inverter, 500 ... battery, 510 ... SOC sensor, 600 ... vehicle speed sensor.

Claims (6)

In a hybrid vehicle including a motor generator and an internal combustion engine as a power source, an internal combustion engine control device for a hybrid vehicle that controls the internal combustion engine,
Torque specifying means for specifying the torque of the internal combustion engine;
Fuel consumption rate calculation means for calculating an instantaneous fuel consumption rate in the internal combustion engine based on the identified torque, the rotational speed of the internal combustion engine, and a fuel injection amount in the internal combustion engine;
Based on the calculated fuel consumption rate, an operation line update unit that updates a preset operation line on a coordinate plane having the torque and the rotation speed as the first axis and the second axis, respectively;
Operating point setting means for setting an operating point of the internal combustion engine on the operating line;
Control means for controlling the operating state of the internal combustion engine according to the set operating point,
The operating point setting means, when the point on the operating line to be set as the operating point exists in a region where the efficiency of the internal combustion engine is locally low on the operating line, (i) the point to be set And (ii) a first setting selected from a first region on the low output side with respect to the point to be set in a predetermined range including the point to be set on the operation line. A second setting process for alternately setting the second operation point selected from the second region on the high output side with respect to the operation point and the point to be set as the operation point so that the required output is maintained; Of these, the processing having the higher efficiency is performed. An internal combustion engine control device for a hybrid vehicle. The internal combustion engine control device for a hybrid vehicle according to claim 1, wherein the predetermined range is defined based on a charge / discharge characteristic of a battery that supplies power to the motor generator. The hybrid vehicle according to claim 1, wherein the operation point setting unit selects an operation point having the highest efficiency in each of the first and second regions as the first and second operation points. The internal combustion engine control device. The operating point setting means prohibits the second setting process during a period when the speed of the hybrid vehicle is less than a predetermined speed and a period when the output of the internal combustion engine is less than a predetermined output value. The internal combustion engine control device for a hybrid vehicle according to any one of claims 1 to 3. In a hybrid vehicle including a motor generator and an internal combustion engine as a power source, an internal combustion engine control device for a hybrid vehicle that controls the internal combustion engine,
Torque specifying means for specifying the torque of the internal combustion engine;
Fuel consumption rate calculation means for calculating an instantaneous fuel consumption rate in the internal combustion engine based on the identified torque, the rotational speed of the internal combustion engine, and a fuel injection amount in the internal combustion engine;
Based on the calculated fuel consumption rate, an operation line update unit that updates a preset operation line on a coordinate plane having the torque and the rotation speed as the first axis and the second axis, respectively;
Operating point setting means for setting an operating point of the internal combustion engine on the operating line;
Control means for controlling the operating state of the internal combustion engine according to the set operating point,
The operating point setting means should set the operating point on the operating line when the point on the operating line to be set as the operating point exists in a region where the efficiency of the internal combustion engine is locally low on the operating line. A first operating point selected from a first region that is on the low output side relative to the point to be set in a predetermined range including a point, and a second selected from a second region that is on the high output side relative to the point to be set An internal combustion engine control apparatus for a hybrid vehicle, wherein an operating point is alternately set as the operating point so that the required output is maintained. In a hybrid vehicle including a motor generator and an internal combustion engine as a power source, an internal combustion engine control method for a hybrid vehicle for controlling the internal combustion engine,
A torque specifying step for specifying the torque of the internal combustion engine;
A fuel consumption rate calculating step of calculating an instantaneous fuel consumption rate in the internal combustion engine based on the identified torque, the rotational speed of the internal combustion engine, and a fuel injection amount in the internal combustion engine;
Based on the calculated fuel consumption rate, an operation line update step for updating a preset operation line on a coordinate plane having the torque and the rotation speed as the first axis and the second axis, respectively;
An operating point setting step of setting an operating point of the internal combustion engine on the operating line;
A control step of controlling the operating state of the internal combustion engine according to the set operating point,
In the operating point setting step, when the point on the operating line to be set as the operating point exists in a region where the efficiency of the internal combustion engine is locally low on the operating line, (i) the point to be set And (ii) a first setting selected from a first region on the low output side with respect to the point to be set in a predetermined range including the point to be set on the operation line. A second setting process for alternately setting the second operation point selected from the second region on the high output side with respect to the operation point and the point to be set as the operation point so that the required output is maintained; Of these, the process having the higher efficiency is performed. An internal combustion engine control method for a hybrid vehicle.

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