JP3543566B2 - Control system for hybrid system vehicle - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a control device for a hybrid system vehicle combining an engine and a motor generator.
[0002]
[Prior art]
2. Description of the Related Art A hybrid vehicle combining an engine and an electric motor (motor generator) to improve exhaust emission has been conventionally known, for example, Japanese Patent Application Laid-Open No. 3-121928.
[0003]
This is a parallel hybrid system in which the engine and the electric motor are arranged in parallel. The vehicle runs by adding the driving force of the electric motor to the driving force of the engine under predetermined driving conditions, and generates electric power during coasting or deceleration. In order to improve the thermal efficiency and exhaust emission of the engine by regenerating energy as a machine, when driving an electric motor, the distribution of the driving torque between the engine and the electric motor is variably controlled to control the thermal efficiency of the engine. And the exhaust emission is controlled to be in the best condition.
[0004]
[Problems to be solved by the invention]
In such a conventional control device for a hybrid system vehicle, the response of the electric motor is not linearly controlled. That is, when controlling the electric motor to the target torque, if the command torque is rapidly increased, hunting may occur at a high torque as shown in FIG. Therefore, the torque is increased by making the change in the instruction torque gradual.
[0005]
However, in this case, if the amount of change in the instruction torque is kept constant, a good response of the electric motor is not always obtained, resulting in insufficient acceleration during acceleration. In addition, similarly, there is a problem of insufficient braking during regeneration and insufficient collection of regenerative electric energy.
[0006]
SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to improve the performance of a hybrid system vehicle by performing optimal control of an electric motor and an engine.
[0007]
[Means for Solving the Problems]
A first invention provides a motor generator connected to an engine, torque distribution means for setting a target torque value of the engine and the motor generator based on an operation state, and controlling an output of the engine based on the target torque value of the engine. On the other hand, in a control device for a hybrid system vehicle including a controller for controlling a motor generator based on a torque target value of the motor generator, the torque of the motor generator is determined according to the current torque value of the motor generator and the torque target value of the motor generator. A delay detecting means for setting a change amount of the command torque instructing the value to be the torque target value, and detecting a delay of an actual torque of the motor generator with respect to the command torque value of the motor generator; Change the amount of change in indicated torque Providing a command torque change amount changing means that.
[0009]
According to a second aspect of the present invention, a motor generator connected to the engine, torque distribution means for setting a target torque value of the engine and the motor generator based on an operation state, and controlling an output of the engine based on the target torque value of the engine. On the other hand, in a control device for a hybrid system vehicle including a controller for controlling a motor generator based on a torque target value of the motor generator, the torque of the motor generator is determined according to the current torque value of the motor generator and the torque target value of the motor generator. with value sets the amount of change in indicated torque to instruct so as to torque target value, providing a commanded torque change amount changing means for changing the change amount of the command torque in accordance with the coolant temperature of the engine.
[0010]
A third invention is a motor generator connected to an engine, torque distribution means for setting a target torque value of the engine and the motor generator based on an operation state, and controlling an output of the engine based on the target torque value of the engine. On the other hand, in a control device for a hybrid system vehicle including a controller for controlling a motor generator based on a torque target value of the motor generator, the torque of the motor generator is determined according to the current torque value of the motor generator and the torque target value of the motor generator. While setting the amount of change of the instructed torque instructing the value to be the torque target value, the torque distribution means relatively increases the engine torque target value during warm-up of the engine, and increases the torque target value of the motor generator. Make the value relatively small.
[0011]
【The invention's effect】
According to the first aspect, it is possible to obtain an optimum instruction torque to the torque target value of the motor generator, secure a high response of the motor generator during power running, and improve the starting and acceleration performance. In addition, good braking performance can be secured during deceleration, and energy regeneration performance can be improved.
[0013]
According to the second aspect , the response of the motor generator suitable for the engine can be obtained when the engine is warmed up, and the normal state of the engine can be maintained.
[0014]
According to the third aspect , the warm-up performance is improved.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
As shown in FIG. 1, an engine 10 transmits a driving force to a drive shaft 12, a differential 13 and a drive wheel 14 via an automatic transmission 11.
[0017]
A motor generator 15 arranged in parallel with the engine 10 is connected to a pulley 18 of the engine 10 via a pulley 16 and a belt 17, and the torque generated by the motor generator 15 is transmitted to the transmission 11 via the engine 10. When the vehicle is decelerating, the battery 19 is charged by regenerating energy from the drive shaft 12 via the engine 10 while the vehicle is decelerating.
[0018]
The motor generator 15 operates as starting means for cranking the engine 10 when the engine 10 is started. On the other hand, when predetermined operating conditions such as starting or accelerating the vehicle are satisfied, the torque of the motor generator 15 The start, acceleration, and the like are smoothly performed by adding a torque.
[0019]
Here, the torque distribution between the engine 10 and the motor generator 15 when the vehicle starts or accelerates is controlled by the control unit 20. The control unit 20 includes an accelerator opening sensor 30 for detecting an accelerator pedal opening (depressed amount) ACS for detecting a driving state of the vehicle, and a vehicle speed sensor for detecting a vehicle speed VSP from the rotation speed of the drive shaft 12 and the like. The signal from 31 is input. Further, a rotation speed sensor 32 for detecting the rotation speed of the engine 10, a torque sensor 33 for detecting the torque of the engine 10, a temperature sensor 34 for detecting a cooling water temperature (or oil temperature) of the engine 10, and a rotation of the motor generator 15. Signals from a rotational speed sensor 35 for detecting the number, a torque sensor 36 for detecting the torque of the motor generator 15, and the like are input.
[0020]
The control unit 20 determines a driving state from the detected vehicle speed VSP and the accelerator opening ACS, and if the vehicle is in a start or acceleration state, is a target value of torque to be output to the transmission 11 based on a predetermined map. After the output torque target value T * all is obtained based on the vehicle speed VSP using the accelerator opening ACS as a parameter, a motor torque target value T _M * (T which is a target value of the torque to be generated by the motor generator 15 from a predetermined map. _TARGET ). Similarly, an engine torque target value _TE *, which is a target value of torque to be generated by the engine 10, is determined from the output torque target value T * all from a predetermined map.
[0021]
Engine control unit 21 of the control unit 20, based on the engine torque target value T _E * performs fuel injection control and ignition timing of the engine 10 control, etc., the actual engine torque T _E by the engine 10 is applied to the transmission 11 Is controlled to match the engine torque target value _TE *.
[0022]
Further, the motor generator control unit 22 of the control unit 20 supplies the electric power of the battery 19 to the motor generator 15 by the inverter 23 based on the motor torque target value T _M *, and the motor generator 15 Is controlled so as to match the actual motor torque T _{M applied} to the motor torque target value T _M *.
[0023]
In this case, the motor generator control unit 22 controls a change amount t ₁ ( depending on a time constant) of the instruction torque to the motor torque target value T _M *, that is, the instruction torque for controlling the power supplied from the inverter 23 to the motor generator 15. Then, control is performed so that the motor torque T _M matches the target value T _M * with high response.
[0024]
Next, the control performed by the control unit 20 (motor generator control unit 22) will be described with reference to the flowchart of FIG. This flowchart is executed immediately after the calculation of the torque target values, and is executed, for example, every several milliseconds.
[0025]
First, in step 1, a motor torque target value T _M * (T _TARGET ) is read.
[0026]
In step 2, the current rotation speed N _NOW and the torque T _NOW of the motor generator 15 are read, and the displacement torque ΔT that is the difference between the motor torque target value T _TARGET and the current torque T _NOW is obtained. The time constant t ₁ of the designated torque is read from the designated torque map set as shown in FIG. 3 based on the rotation speed N _NOW and the torque T _NOW .
[0027]
The instruction torque map forms a group (A, B,... X) for each predetermined range of the rotation speed N _NOW , the torque T _NOW , and the displacement torque ΔT, and a time constant t ₁ (a, b) of the instruction torque for each group. ,... X) are set, and the time constant t ₁ is set smaller on the X side of the group. Also, for each group, the maximum allowable the delay time reference of the actual torque and the command torque value when instructed torque target value in a predetermined range at the appropriate time constants t ₁ to the inverter 23 delay t ₂ and the minimum delay t ₃ is set. Note that each time constant t ₁ is set to a value that obtains the highest response of the motor generator 15 within a range that does not basically cause hunting.
[0028]
When the time constant t ₁ is read from the corresponding group of the indicated torque map, the motor torque target value T _M * is instructed to the inverter 23 at the time constant t _{1 in} step 3. That is, the command torque is increased by the time constant t ₁ , and the command torque is finally set to the motor torque target value T _M *. The command torque curve in this case is as shown in FIG. The command torque increases along the command torque curve.
[0029]
As a result, the torque of motor generator 15 increases to reach target value T _M * . At this time, in step 4, as shown in FIG. 5, the actual torque with respect to the indicated torque value of motor generator 15 (on the dotted line) is obtained. The delay time Δt of T _M is measured. This is a delay from the time when this is instructed to the time when the actual torque T _M becomes equal to the indicated torque value TH with respect to the instructed torque value TH when the torque target value in the predetermined range is instructed by the time constant t ₁ . The time Δt is measured. In this case, the actual torque T _M is checked and measured at a sampling period of several μsec.
[0030]
Then, in steps 5 to 7, Δt is compared with the maximum allowable delay t ₂ and the minimum delay t ₃ of the corresponding group in the indicated torque map from which the time constant t ₁ has been read.
[0031]
If Δt is t ₃ ≦ Δt ≦ t ₂ , the time constant t ₁ is appropriate, so the process proceeds to step 8 and the selection of the group of the indicated torque map is not changed.
[0032]
When Δt <t ₃ , the time constant t ₁ is too small, and the process proceeds to step 9 to reduce the rank of the group to be selected in the designated torque map.
[0033]
If Δt> t ₂ , the time constant t ₁ is too large, so the process proceeds to step 10 to increase the rank of the group to be selected in the indicated torque map.
[0034]
The ranks of these groups are changed at the time of the next torque instruction.
[0035]
Therefore, good and high response of motor generator 15 can be obtained.
[0036]
Then, the rotational speed N _E of the engine 10 at step 11, the torque T _E, and check the coolant temperature (or oil temperature) Temp, at step 12-15 that the rotational speed N _E, the torque T _E, indicated by the coolant temperature Temp The rank of the torque map group is determined.
[0037]
In this case, as shown in FIG. 6, the minimum temperature limit Temp (min), the standard temperature Temp (Normal), the maximum temperature limit Temp (max), etc. of the cooling water temperature Temp are set for each predetermined range of the rotation speed N _E and the torque T _E. When the set engine state map is provided and the cooling water temperature Temp is Temp> Temp (Normal), the rank of the indicated torque map group is not changed (steps 16 and 18), and when Temp <Temp (min). Then, the rank of the group to be selected in the instruction torque map is reduced (step 17).
[0038]
This rank change is performed at the time of the next torque instruction. At this time, instead of changing the rank, a correction value may be determined, and the time constant t ₁ of the corresponding group may be corrected at the next torque instruction.
[0039]
Therefore, when the engine 10 is warmed up, a response of the motor generator 15 suitable for the engine can be obtained.
[0040]
With this configuration, a high response of the motor generator 15 can be obtained during power running without causing hunting in the control, and the starting and acceleration performance is improved.
[0041]
In this case, since the time constant of the indicated torque is changed according to the delay of the actual torque with respect to the indicated torque value of motor generator 15, higher response of motor generator 15 can be obtained.
[0042]
In addition, when the engine 10 is warmed up, the response of the motor generator 15 suitable for the engine can be obtained, and the normal state of the engine 10 with little load fluctuation can be maintained.
[0043]
At the time of deceleration, the energy is regenerated from the motor generator 15 and the battery 19 is charged. In this case, the deceleration torque target value T _TARGET is obtained from the vehicle speed VSP or the like, and the current rotation speed N _NOW and torque T _{NOW of the} motor generator 15 are obtained. If, based on the deceleration torque target value T _tARGET displacement torque ΔT is a difference between the torque T _{the NOW,} reads the constant t ₁ when the command torque from the command torque map, the deceleration torque target value T at the time constant t _{1 TARGET} is instructed to the inverter 23. That is, during regeneration, the target value T _TARGET only decreases, so the sign of the displacement torque ΔT is taken and control is performed in the same manner as during power running. Therefore, as shown in FIG. 7, good braking performance can be obtained during deceleration, and energy regeneration performance is improved.
[0044]
FIG. 8 shows another embodiment of the present invention, in which the torque distribution between the engine 10 and the motor generator 15 is changed when the cooling water temperature (or oil temperature) of the engine 10 is lower than a predetermined value. In this case, based on the cooling water temperature, a predetermined value α determined by the cooling water temperature is added to the engine torque target value _TE * with respect to the normal state shown in FIG. Subtract from the target value T _M *.
[0045]
By doing so, warming up of the engine 10 can be promoted. During warm-up, the time constant t ₁ of the command torque of the motor generator 15 is increased as described above.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a first embodiment.
FIG. 2 is a flowchart showing control contents.
FIG. 3 is a diagram showing an example of a command torque map.
FIG. 4 is a characteristic diagram of a command torque curve.
FIG. 5 is a characteristic diagram showing a command torque and an actual delay.
FIG. 6 is a diagram showing an example of an engine state map.
FIG. 7 is a characteristic diagram showing brake performance and engine regeneration performance.
FIG. 8 is a characteristic diagram of torque distribution according to the second embodiment.
FIG. 9 is a characteristic diagram of torque distribution in a normal state.
FIG. 10 is a characteristic diagram showing hunting of control in a conventional example.
[Explanation of symbols]
Reference Signs List 10 engine 11 automatic transmission 12 drive shaft 13 differential device 14 drive wheel 15 motor generator 19 battery 20 control unit 21 engine control unit 22 motor generator control unit 23 inverter 30 accelerator opening sensor 31 vehicle speed sensor 32 rotation speed sensor 33 torque sensor 34 temperature sensor 35 rotation speed sensor 36 torque sensor

Claims (3)

A motor generator coupled to the engine, torque distribution means for setting a torque target value for the engine and the motor generator based on the operating state, and controlling the output of the engine based on the target torque value for the engine, And a controller for controlling the motor generator based on the target value.
In accordance with the current torque value of the motor generator and the torque target value of the motor generator, the amount of change of the command torque for instructing the torque value of the motor generator to become the torque target value is set , and
A delay detecting means for detecting a delay of an actual torque of the motor generator with respect to a command torque value of the motor generator, and a command torque change amount changing means for changing a change amount of the command torque based on the delay are provided. Control device for a hybrid system vehicle. A motor generator coupled to the engine, torque distribution means for setting a torque target value for the engine and the motor generator based on the operating state, and controlling the output of the engine based on the target torque value for the engine, And a controller for controlling the motor generator based on the target value.
In accordance with the current torque value of the motor generator and the torque target value of the motor generator, the amount of change of the command torque for instructing the torque value of the motor generator to become the torque target value is set, and
A control device for a hybrid system vehicle, comprising: a command torque change amount changing means for changing a change amount of the command torque according to a cooling water temperature of an engine . A motor generator coupled to the engine, torque distribution means for setting a torque target value for the engine and the motor generator based on the operating state, and controlling the output of the engine based on the target torque value for the engine, And a controller for controlling the motor generator based on the target value.
In accordance with the current torque value of the motor generator and the torque target value of the motor generator, the amount of change of the command torque for instructing the torque value of the motor generator to become the torque target value is set, and
The control device for a hybrid system vehicle, wherein the torque distribution unit relatively increases the target torque value of the engine during warm-up of the engine and relatively decreases the target torque value of the motor generator .

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