JP2020055411A - Hybrid-vehicular control method and control apparatus - Google Patents

Abstract

To realize an improvement of fuel economy by suppressing extraneous fuel consumption while satisfying an acceleration response required by a driver during a series travel.SOLUTION: A control method is applied to a series hybrid vehicle that includes an engine 1, a motor-generator 2, a drive motor 3 and a battery 8, and switches between an engine-stop mode and an engine power-generating mode during a series travel. The method includes: obtaining vehicle-itself positional information and travel estimation information that estimates a travel mode ahead of the present position of the vehicle itself during a travel with the engine-stop mode; predicting required drive power required for the vehicle itself to travel from the present position along a travel-plan road on the basis of the vehicle-itself positional information and travel estimation information; and switching from the engine-stop mode to the engine power-generating mode in which to start the engine 1 for generating power with the motor-generator 2 in a case where the required drive power is predicted to be higher than a threshold, or maintaining the engine-stop mode in a case where the required drive power is predicted to be lower than the threshold.SELECTED DRAWING: Figure 6

Description

  The present disclosure relates to a control method and a control device for a series-running hybrid vehicle.

  Conventionally, by depressing the accelerator pedal while the engine is stopped, the engine is started when the vehicle speed reaches a predetermined value, and the engine speed of the series hybrid vehicle that generates power by setting the engine speed higher than the speed of the drive motor An apparatus is known (for example, see Patent Document 1).

JP 2012-144138 A

  However, in the conventional device, during high-speed running at a vehicle speed equal to or higher than a predetermined value, engine power generation is always maintained to satisfy the driver's acceleration response request. For this reason, there has been a problem that fuel efficiency has not been sufficiently obtained due to wasteful fuel consumption due to maintenance of engine power generation.

  The present disclosure has been made in view of the above problems, and has as its object to improve fuel economy by suppressing unnecessary fuel consumption while satisfying a driver's acceleration response requirement during series running.

To achieve the above object, the present disclosure mounts an engine, a power generation motor, a drive motor, and a battery, and switches between an engine stop mode and an engine power generation mode during series running. In this hybrid vehicle, the control method is as follows.
During traveling in the engine stop mode, the vehicle position information and traveling estimation information for estimating the traveling mode ahead from the current position of the vehicle are obtained.
Based on the vehicle position information and the travel estimation information, a required driving force required when the vehicle travels from the current location along the road to be traveled is predicted.
When the required driving force is predicted to be larger than the threshold value, the engine is switched from the engine stop mode to the engine power generation mode in which the engine is started and the electric power is generated by the power generation motor. maintain.

  For this reason, during series running, it is possible to achieve an improvement in fuel efficiency by suppressing unnecessary fuel consumption while satisfying the driver's acceleration response request.

FIG. 1 is an overall system diagram showing a drive system and a control system of a series hybrid vehicle to which a control method and a control device according to a first embodiment are applied. FIG. 3 is a control mode diagram showing each control mode executed when the vehicle speed is lower than a predetermined vehicle speed by an engine power generation / stop control unit of the vehicle control module according to the first embodiment. 4 is a flowchart illustrating a flow of a driver driving preference learning control process for each driving scene executed by a driver driving preference learning control unit of the vehicle control device of the first embodiment. It is a judgment item illustration diagram showing an example of each judgment item in the driving style used in the driver driving preference learning control, the driving environment (Navi information), and the driving situation near the own vehicle. FIG. 6 is a driving scene classification diagram showing a driving scene classification example based on a combination of driving environment determination items used in driver driving preference learning control. 4 is a flowchart illustrating a flow of an engine power generation / stop control process executed by an engine power generation / stop control unit of the vehicle control module according to the first embodiment. 9 is a time chart showing characteristics in a high vehicle speed engine power generation control of a comparative example. 3 is a time chart illustrating various characteristics in the engine power generation / stop control at a high vehicle speed according to the first embodiment. 5 is a time chart showing characteristics of an acceleration lag when the engine is started simultaneously with a driver acceleration request in the engine power generation / stop control at a high vehicle speed. 6 is a time chart showing various characteristics with no acceleration lag when starting the engine prior to a driver acceleration request based on prediction of a required driving force in engine power generation / stop control at a high vehicle speed.

  Hereinafter, embodiments for implementing a control method and a control device for a hybrid vehicle according to the present disclosure will be described based on a first embodiment illustrated in the drawings.

  The control method and control device of the first embodiment are applied to a series hybrid vehicle (an example of a hybrid vehicle) that runs in series using an engine as a power source for power generation and a drive motor as a drive source for traveling. Hereinafter, the configuration of the first embodiment is divided into “entire system configuration”, “detailed configuration of vehicle control module”, “driver driving preference learning control processing configuration for each driving scene”, and “engine power generation / stop control processing configuration”. explain.

[Overall system configuration]
FIG. 1 illustrates a drive system and a control system of a series hybrid vehicle to which the control method and the control device according to the first embodiment are applied. Hereinafter, the overall system configuration will be described with reference to FIG.

  As shown in FIG. 1, the drive system of the series hybrid vehicle includes an engine 1 (Eng), a generator motor 2 (MG1), a drive motor 3 (MG2), a gear box 4, and front drive shafts 5L and 5R. , Front wheels 6L and 6R (drive wheels). As components connected to the power generation motor 2 and the drive motor 3, a power generation motor / drive motor inverter 7 and a battery 8 are provided. In FIG. 1, 9L and 9R are rear wheels (driven wheels).

  The engine 1 is a horizontal engine that is arranged in a power unit room at the front of the vehicle and has a crankshaft direction in a vehicle width direction. The main body of the engine 1 is connected and fixed to a gear case side surface of the gear box 4.

  The generator motor 2 and the drive motor 3 are both permanent-magnet synchronous motors / generators using three-phase alternating current, are arranged in the power unit room at the front of the vehicle, and are mounted on the gear box side opposite to the engine fixed side of the gear box 4. It is connected and fixed side by side. The power generation motor 2 has both a power generation function of converting drive energy from the engine 1 into power generation energy and a starter motor function of the engine 1. The drive motor 3 has a drive function of driving the front wheels 6L, 6R with the power of at least one of the power generation motor 2 and the battery 8, a regenerative function of converting the rotational energy of the front wheels 6L, 6R into power generation energy and charging the battery 8. And

  The gear box 4 is configured by disposing a gear train 4a, a reduction gear train 4b, and a differential gear unit 4c in a gear case in which the engine 1, the power generation motor 2, and the drive motor 3 are connected and fixed. The gear train 4a drives and connects the engine 1 and the generator motor 2. The reduction gear train 4b drives and connects the drive motor 3 and the differential gear unit 4c. The differential gear unit 4c drives and connects the reduction gear train 4b and the front drive shafts 5L and 5R while allowing the front drive shafts 5L and 5R to be differential.

  The generator motor / drive motor inverter 7 is disposed in the power unit room at the front of the vehicle, is connected to the generator motor 2 and the drive motor 3 via three AC harnesses 10 and 11 respectively, and is connected to the battery 8. It is connected via two DC harnesses 12. The generator motor / drive motor inverter 7 converts three-phase AC to DC when power is generated by the generator motor 2 and converts DC from the battery 8 to three-phase AC when the engine is started by the generator motor 2. In addition, when driving by the drive motor 3, the DC from the battery 8 is converted into a three-phase AC, and during regeneration by the drive motor 3, the three-phase AC generated by the drive motor 3 is converted into DC, and the battery 8 is charged.

  As shown in FIG. 1, the control system of the series hybrid vehicle includes a vehicle control module 20 (VCM), an engine controller 21 (EC), a motor generator controller 22 (MGC), and a battery controller 23 (BC). Have. Further, a navigation control unit 24 (NAVICU) and a driving support control unit 25 (ADASCU) are provided. These control devices 20, 21, 22, 23, 24, 25 are connected by a CAN communication line 26 capable of exchanging information.

  The vehicle control module 20 has a function of appropriately managing the energy consumption of the entire series hybrid vehicle, and is an integrated control unit that controls operations of the engine 1, the power generation motor 2, and the drive motor 3. The vehicle control module 20 receives in-vehicle sensor information such as an accelerator opening sensor 27, a vehicle speed sensor 28, a front and rear G sensor 29, and a lateral G sensor 30. Information on the battery charge capacity (hereinafter referred to as “battery SOC”) is input from the battery controller 23 via the CAN communication line 26. In addition, necessary information is input from the navigation control unit 24 and the driving support control unit 25 via the CAN communication line 26. Then, operation / stop control of the engine 1 is performed by outputting a control command to the engine controller 21, and operation control of the power generation motor 2 and the drive motor 3 is performed by outputting a control command to the motor generator controller 22.

  The navigation control unit 24 automatically determines the current position of the vehicle during traveling, compares the current position with the stored map data, displays a route on the map on the screen of the display 31, and provides route guidance by voice or the like. It has a function to guide the driver to the destination. The navigation control unit 24 includes a display 31, a storage device 32, and a communication device 33. In addition, as the display 31, a monitor arranged at an instrument panel position in a vehicle cabin or a head-up display for displaying an image on a front window is used.

  The navigation control unit 24 receives a signal from the GPS satellite 34 and detects the absolute position (position specified by longitude and latitude) of the own vehicle on the earth. Then, referring to the map stored in the storage device 32, the current position, which is the position where the host vehicle is currently located, is specified, and the planned traveling route from the current position to the destination is set.

  The storage device 32 stores road environment information such as a radius of curvature of a road, a gradient, an intersection, a signal, a railroad crossing, a pedestrian crossing, a speed limit, a tollgate, and road attribute information (expressway, main road, general road, residential area, etc.). Including map information. Further, the storage device 32 also stores drive style data (accelerator operation, front / rear G, lateral G, etc.) of the own vehicle in the past traveling section.

  The communication device 33 performs wireless communication (telematics communication) with a data center 35 having traffic information and statistical traffic data via a communication network such as a wireless base station (not shown) and the Internet. This "communication" is bidirectional, and information can be transmitted from the navigation control unit 24 to the data center 35. Conversely, the information is received from the data center 35 and the state of the road to be traveled (congestion information and the like) is determined. It is possible to enter.

  The driving assistance control unit 25 is a driving assistance control device that performs a driving / braking / steering control function and reduces a driver's driving burden by automatic braking control, garage parking control, single-lane automatic driving control, and the like. is there.

  Information from an automatic driving switch 36, a vehicle-mounted camera 37, a rider / radar 38, and the like is input to the driving support control unit 25. The drive control function is exerted by controlling the drive force of the drive motor 3 via the CAN communication line 26. Among the braking control functions, the regenerative braking function is exerted by controlling the regenerative force by the drive motor 3 via the CAN communication line 26. The brake braking function is exerted by outputting a brake braking command to the brake actuator 39. The steering control function is exerted by outputting a steering control command to a steering actuator 40 provided in the steering system.

  When the driver turns on the automatic driving switch 36, the driving mode is switched from the manual driving mode to the single lane automatic driving mode.

  The in-vehicle camera 37 is mounted on the own vehicle and acquires image information around the own vehicle. For example, the around view monitor system is configured by combining a front recognition camera, a rear recognition camera, a right recognition camera, and a left recognition camera. The in-vehicle camera 37 includes an object on the own vehicle traveling road and an object outside the own vehicle traveling road (road structure, preceding vehicle, following vehicle, oncoming vehicle, surrounding vehicle, pedestrian, bicycle, two-wheeled vehicle), own vehicle traveling road (road white line) , Road boundaries, stop lines, pedestrian crossings) and road signs (speed limit) are detected.

  The rider / radar 38 is a distance measuring sensor mounted on the own vehicle, and detects the presence of an object around the own vehicle by receiving a reflected wave of the output wave, and also detects the distance to an object around the own vehicle. . For example, a laser radar, a millimeter wave radar, an ultrasonic radar, a laser range finder, or the like can be used. In this rider / radar 67, the position of an object on the own vehicle traveling road and an object outside the own vehicle traveling road (road structure, a preceding vehicle, a following vehicle, an oncoming vehicle, a surrounding vehicle, a pedestrian, a bicycle, a two-wheeled vehicle) and the like are determined. Detect distance.

[Detailed configuration of vehicle control module]
FIG. 2 shows each control mode executed by the engine power generation / stop control unit 20c of the vehicle control module 20 (controller) of the first embodiment when the vehicle speed is lower than a predetermined vehicle speed. Hereinafter, a detailed configuration of the vehicle control module 20 will be described with reference to FIGS. 1 and 2.

  During the series running, when the vehicle speed VSP is equal to or higher than the predetermined vehicle speed, the vehicle control module 20 executes the switching control between the “engine stop mode” and the “engine power generation mode” based on the prediction of the required driving force. Here, the “engine stop mode” is a control mode in which the engine 1 is stopped and power is supplied to the drive motor 3 from the battery 8. The “engine power generation mode” is a control mode in which the engine 1 is started and power is supplied to the drive motor 3 from the battery 8 and the power generation motor 2. When the vehicle speed VSP is lower than the predetermined vehicle speed, the switching control in the normal control mode shown in FIG. 2 is executed.

  As shown in FIG. 1, the vehicle control module 20 includes an information obtaining unit 20a, a required driving force prediction unit 20b, an engine power generation / stop control unit 20c, and a driver driving preference learning unit 20d.

  During traveling in the "engine stop mode", the information acquiring unit 20a acquires the vehicle position information and the traveling estimation information for estimating the traveling mode ahead from the current position of the vehicle.

  Here, in the first embodiment, the traveling environment information along the road to be traveled ahead of the current position of the own vehicle and the learning result of the driver's driving preference are obtained as the traveling estimation information.

  The required driving force prediction unit 20b predicts the required driving force required when the vehicle travels from the current location along the road to be traveled, based on the vehicle position information and the travel estimation information.

  Here, the required driving force is predicted by adding the learning result of the driver's driving preference to the magnitude of the change in the traveling load based on the traveling environment information when the vehicle travels from the current location along the road to be traveled. In other words, the required driving force is predicted by adding a driver request based on the driver's driving preference to the required driving force determined by the magnitude of the traveling load.

  When the required driving force is predicted to be larger than the threshold, the engine power generation / stop control unit 20c switches from the “engine stop mode” to the “engine power generation mode” in which the engine 1 is started and the power generation motor 2 generates power. On the other hand, if the required driving force is predicted to be smaller than the threshold, the “engine stop mode” is maintained.

  If it is determined that the magnitude of the change in the traveling load is larger than the threshold during traveling while selecting the “engine stop mode”, the own vehicle is located at a position a predetermined distance before the acceleration event in which the variation in the traveling load becomes large. Determine if it has arrived. When the vehicle reaches a predetermined distance before the acceleration event, the engine 1 is started and switched to the “engine power generation mode” in which the power is generated by the power generation motor 2 irrespective of the learning result of the driver's driving preference.

  If the magnitude of the change in the traveling load is determined to be equal to or less than the threshold during traveling with the “engine stop mode” selected, inter-vehicle distance information between the own vehicle and the surrounding vehicles is obtained. When the preceding vehicle is present within a predetermined distance, if the driver's driving preference is that of passing the preceding vehicle, the driving mode is switched to the “engine power generation mode” in which the engine 1 is started and the power generation motor 2 generates electric power. If it is a car follower, the "engine stop mode" is maintained.

  During the series running in the “engine power generation mode”, the rotation speed of the engine 1 is set to a region where the power generation efficiency of the power generation motor 2 is high. When the battery SOC exceeds the upper limit capacity due to the series running in the “engine power generation mode”, the mode is switched from the “engine power generation mode” to the “engine stop mode”.

  The driver's driving preference learning unit 20d learns whether the driver's driving preference is front vehicle overtaking or front vehicle following.

  Here, the driver driving preference learning unit 20d divides the traveling scene of the vehicle into a plurality of traveling scenes by a combination of the traveling environment determination items. Then, when a front vehicle is present in front of the own vehicle, it learns whether the driver's driving preference is front vehicle overtaking or front vehicle following for each of the divided traveling scenes.

  Next, control modes that are switched when the vehicle speed VSP is lower than the predetermined vehicle speed will be described with reference to FIG. In FIG. 2, the black arrows indicate the flow of electric power, and the white arrows indicate the flow of engine power.

(a) Normal start / running (engine off)
At the time of normal start / run when the remaining amount of the battery SOC is sufficient, as shown in FIG. 2A, the engine 1 is stopped, and the drive motor 3 runs while consuming the charging power to the battery 8. Note that the engine 1 is started when the vehicle normally starts and runs, and when the heater is used.

(b) Normal start / running (engine ON)
At the time of normal start and running when the remaining amount of the battery SOC is small, as shown in FIG. 2B, while the power generated by running the engine 1 at a fuel-efficient rotation speed is charged in the battery 8, The vehicle travels with the drive motor 3 consuming the power of the battery 8 and the power of the generator motor 2.

(c) Sudden acceleration / uphill When sudden acceleration / uphill, electric power is supplied from both the generator motor 2 and the battery 8 to the drive motor 3. Thus, the drive motor 3 increases the output by supplying a large amount of electric power, thereby realizing a powerful running that increases the vehicle speed at a stretch at the time of sudden acceleration, and realizing an uphill running that overcomes a large running load at the time of uphill.

(d) During deceleration and descent During deceleration and descent, the load torque by the drive motor 3 is given to the front wheels 6L and 6R as deceleration torque. Then, the electric power regenerated by the drive motor 3 is charged in the battery 8. When the battery SOC has reached the upper limit or more, the engine 1 is cranked by the power generation motor 2 for discharging.

[Driver preference learning control processing configuration for each driving scene]
FIG. 3 shows a flow of the driver driving preference learning process for each driving scene executed by the driver driving preference learning unit 20d of the vehicle control module 20 of the first embodiment. Hereinafter, each step of FIG. 3 will be described with reference to FIGS. 4 and 5. It should be noted that the driver driving preference learning process for each driving scene is always executed while the vehicle is traveling by manual driving that can learn the driver driving preferences.

  In step S1, following the start by turning on the ignition switch or the determination of NO in S3, necessary information in the driver driving preference learning control is read, and the process proceeds to step S2. The necessary information in the driver driving preference learning control read in step S1 includes, for example, drive style information (accelerator opening, etc.), traveling environment information (road type, road gradient, curve, congestion, etc.) and information on the vicinity of the vehicle. It is traveling state information (inter-vehicle distance, relative vehicle speed, etc.).

  Here, FIG. 4 shows an example of each determination item in the drive style, the driving environment (Navi information), and the driving condition near the own vehicle used in the driver driving preference learning control. That is, the determination items of the drive style include the accelerator operation, the front and rear G, and the horizontal G. The determination items of the driving environment (Navi information) include a curve (distance), a curve (curvature), a gradient (gradient), a gradient (position), a tollgate (distance), an intersection (distance), a road type, GPS, and congestion information. (Average vehicle speed) and traffic signal information (distance). The determination items of the driving situation near the own vehicle include a distance from another vehicle, a vehicle speed of the other vehicle (position prediction / relative vehicle speed), and traffic signal information (color). As described above, the necessary information in the driver driving preference learning control is included in the determination items shown in FIG.

  In step S2, following S1, the driving scene X at that time is determined by a combination of the determination items of the driving environment, and the process proceeds to step S3.

  Here, FIG. 5 shows an example of the division of the driving scene by the combination of the driving environment judgment items used in the driver driving preference learning control. For example, if the classification of the driving scene is determined by a combination of the judgment items of the driving environment such as road type, road gradient, curve, and traffic congestion, the driving scene is a climbing road traveling scene on a highway on a straight road and there is no traffic congestion. Scene X is determined to be section A. When the vehicle is traveling on an uphill road on a curved road and there is no traffic congestion, the traveling scene X is determined as Category B. Further, when the vehicle is traveling on an uphill road on a curved road and there is traffic congestion, the traveling scene X is determined to be the category C.

In step S3, following S2, it is determined whether or not a preceding vehicle exists in front of the own vehicle and the inter-vehicle distance between the own vehicle and the preceding vehicle is equal to or less than a predetermined value. If YES (inter-vehicle distance ≦ predetermined value), the process proceeds to step S4, and if NO (no preceding vehicle or inter-vehicle distance> predetermined value), the process returns to step S1.
Here, the "predetermined value of the inter-vehicle distance" is set to, for example, the inter-vehicle distance corresponding to the vehicle speed when the vehicle follows the preceding vehicle in the automatic driving mode.

  In step S4, following the determination of YES in S3, it is determined whether the relative vehicle speed between the host vehicle and the preceding vehicle is equal to or higher than a predetermined vehicle speed, and whether the accelerator opening is equal to or higher than the predetermined opening. When YES (relative vehicle speed ≧ predetermined vehicle speed and accelerator opening degree ≧ predetermined opening), the process proceeds to step S6, and when NO (relative vehicle speed <predetermined vehicle speed or accelerator opening <predetermined opening), the process proceeds to step S5. move on.

  Here, the “predetermined vehicle speed of the relative vehicle speed” is set to be equivalent to the approaching vehicle speed at which the own vehicle approaches the preceding vehicle when overtaking the preceding vehicle. The “predetermined opening degree of the accelerator opening” is set to an opening degree that indicates the intention of the host vehicle to accelerate when the host vehicle passes the preceding vehicle.

  In step S5, following the determination of NO in S4, the number N of times of passing the front vehicle is reset to N = 0, and the process proceeds to step S8.

In step S6, following the determination of YES in S4, it is determined whether or not the number of experiences N of passing the preceding vehicle has reached the continuous experience number threshold Nth. If YES (N ≧ Nth), the process proceeds to step S9, and if NO (N <Nth), the process proceeds to step S7.
Here, the “continuous experience count threshold value Nth” is set to, for example, a value of about several times as a continuous experience count value required for the driver to determine that the driver is a passing vehicle.

  In step S7, following the determination of NO in S6, the number N of times of passing the preceding vehicle is added by the equation of N = N + 1, and the process proceeds to step S8.

  In step S8, following S5 or S7, it is learned that the driver's driving preference is front vehicle follower, and the process proceeds to step S10.

  In step S9, following the determination of YES in step S6, it is learned that the driver's driving preference is that of the preceding vehicle, and the process proceeds to step S10.

In step S10, following learning in S8 that the vehicle is a front vehicle follower, or learning in S9 that the vehicle is a front vehicle overtaking, learning results (previous for each of the sections A, B,... Car followers, car overtakers) and save to the end.
Here, in the learning result storage for each of the sections A, B,... Of the traveling scene X, the number N of times of passing the preceding vehicle is also stored for each of the sections A, B,. The learning result of the driver's driving preference and the number of experiences N of passing the preceding vehicle in each of the categories A, B,... Are kept as they are even after the ignition switch is turned off.

[Engine power generation / stop control processing configuration]
FIG. 6 illustrates a flow of the engine power generation / stop control process executed by the engine power generation / stop control unit 20c of the vehicle control module 20 according to the first embodiment. Hereinafter, each step of FIG. 6 will be described. Note that the process of FIG. 6 is repeatedly executed at a predetermined control cycle.

  In step S21, following the start, it is determined whether the vehicle speed VSP is equal to or higher than a predetermined vehicle speed. If YES (vehicle speed VSP ≧ predetermined vehicle speed), the process proceeds to step S22, and if NO (vehicle speed VSP <predetermined vehicle speed), the process proceeds to step S31.

  Here, the "predetermined vehicle speed" is set to a vehicle speed (for example, about 80 km / h) in which the "engine power generation mode" was conventionally fixedly selected in preparation for an acceleration response request during series running.

  In step S22, following the determination of NO in S21, switching control in the normal control mode shown in FIG. 2 is executed, and the process proceeds to the end.

  In step S23, following the determination of YES in S21, it is determined whether or not the series running in the "engine stop mode". If YES (during series running in "engine stop mode"), proceed to step S24; if NO (during series running in "engine power generation mode"), go to step S33.

  Here, since the engine stop flag is set during the execution of the “engine stop mode”, it is determined whether or not the series running in the “engine stop mode” is performed by determining whether the engine stop flag is set. It depends on.

  In step S24, following the determination of YES in S23 or the determination of NO in S27, the current location information of the own vehicle is obtained, and the process proceeds to step S25.

  Here, the “current position information of the own vehicle” is obtained from the navigation control unit 24.

  In step S25, following S24, the driving environment information along the planned road ahead of the current position of the vehicle is obtained, and the process proceeds to step S26.

  Here, "acquisition of traveling environment information" refers to acquisition of destination information, acquisition of a road type, a road gradient, a curve, traffic congestion, and the like of a currently traveling road and a planned traveling road.

  In step S26, following S25, it is determined whether or not the magnitude of the change in the traveling load based on the traveling environment information when the vehicle travels from the current location along the road to be traveled is less than the threshold. If YES (the magnitude of the change in running load <threshold), the process proceeds to step S28; if NO (the size of the change in the running load ≧ threshold), the process proceeds to step S27.

  Here, the “threshold value” is set to the upper limit value of the magnitude of the change in the traveling load that is allowed to maintain the series traveling in the “engine stop mode”.

  In step S27, following the determination of NO in S26, it is determined whether or not the vehicle has arrived at a position a predetermined distance before the acceleration event in which the change in running load is large. If YES (reach the position a predetermined distance before the acceleration event), the process proceeds to step S31; if NO (the position does not reach the predetermined distance before the acceleration event), the process returns to step S24.

  Here, the “predetermined distance” may be obtained from the engine start time required from the start of the engine start to the transition to the engine independent operation and the vehicle speed of the own vehicle. Alternatively, a predetermined fixed time may be given by adding a margin time to the engine start time and the time based on the predetermined vehicle speed.

  In step S28, following the determination of YES in S26, inter-vehicle distance information between the host vehicle and a nearby vehicle is obtained, and the process proceeds to step S29.

  In step S29, following S28, a learning result of the driver's driving preference is obtained for each section of the driving scene, a driving force change amount is predicted based on the learning result of the driver's driving preference, and the process proceeds to step S30.

  Here, the prediction of the driving force change amount is such that when the preceding vehicle exists within a predetermined distance, the driving force change amount is predicted to be larger when the driver's driving preference is the front vehicle overtaking group than when the driver's driving preference is the front vehicle following group. I do. For example, when the vehicle is a front vehicle follower, the change width of the required driving force corresponding to the change of the traveling load is set as the driving force change amount. On the other hand, when the vehicle is a passing vehicle, the required driving force required to pass the vehicle is added to the required driving force change width corresponding to the change in the traveling load.

  In step S30, following S29, it is determined whether or not the predicted driving force change amount is equal to or smaller than a threshold value. If YES (driving force change amount ≦ threshold), the process proceeds to step S32, and if NO (driving force change amount> threshold), the process proceeds to step S31.

  Here, the “threshold value” is set to the upper limit value of the magnitude of the driving force change amount that is allowed to maintain the series running in the “engine stop mode”.

  In step S31, following the determination of YES in S27 or the determination of NO in S30, the mode is switched from the "engine stop mode" to the "engine power generation mode", and the process proceeds to step S34. Alternatively, following the determination of YES in S33, the “engine power generation mode” is maintained, and the process proceeds to step S34.

  In step S32, following the determination of YES in S30, the "engine stop mode" is maintained, and the process proceeds to step S34. Alternatively, following the determination of NO in S33, the mode is switched from the "engine power generation mode" to the "engine stop mode", and the process proceeds to step S34.

  In step S33, following the determination of NO in S23, it is determined whether other engine operating conditions are satisfied. If YES (other engine operating conditions are satisfied), the process proceeds to step S31, and if NO (other engine operating conditions are not satisfied), the process proceeds to step S32.

  Here, "satisfaction of other engine operating conditions" means when the battery SOC has not reached the upper threshold or when the operation of the vehicle air conditioner has started. “Other engine operating conditions are not satisfied” means that the SOC of the battery 8 increases due to the series running in the “engine power generation mode” and the battery SOC becomes equal to or higher than the upper threshold.

  In step S34, following S31 or S32, the vehicle runs in series according to the "engine stop mode" or "engine power generation mode" selected at that time, and proceeds to the end.

  Here, during the series running in the “engine power generation mode”, the rotation speed of the engine 1 is set to a region where the power generation efficiency of the power generation motor 2 is high.

  Next, the operation of the first embodiment is described as "background technology and problem", "problem solving means and problem solving operation", "driver learning preference learning operation for each driving scene", "engine power generation / stop control operation at high vehicle speed". ].

[Background technology and issues]
When the vehicle speed is equal to or higher than a predetermined vehicle speed (80 km / h) (during high-speed driving), it is necessary to keep the engine running for the following reasons even when power generation is not necessary due to the power balance.

  Reason 1: It is necessary to keep the engine running to satisfy the acceleration response requirement. That is, if the engine is started after the request for acceleration and the driving force is output, an acceleration lag time occurs in which the driving force cannot be generated until the engine start is completed, and the acceleration response request cannot be satisfied.

  Reason 2: The predetermined vehicle speed is a vehicle speed at which the maximum torque requested by power supply from only the battery cannot be output.

  For this reason, maintaining the operation of the engine even when the running resistance can be driven only by the power supply from the battery and when power generation is not necessary in terms of the power balance also means that the engine is operated. Fuel efficiency is worse than without.

  Furthermore, if it is judged that the demand for acceleration is not high due to the driving environment or driver's preference, the engine response needlessly needs to be considered, but the engine will be wasted to meet any driving force demand. Is operated to deteriorate fuel efficiency. In addition, since power generation is not required in terms of power balance, power generation must be performed using a low output point having low power generation efficiency, such as low torque and low rotation, which further deteriorates fuel efficiency.

  That is, during high-speed running, as shown in FIG. 7, when the drive motor power MG2Power is constant, and when there is no acceleration response request, the generator motor power MG1Power is controlled by the engine power ENGPower so that the battery SOC maintains a high SOC. Was issued. However, the battery SOC has a high SOC, and does not require power generation in terms of power balance. For this reason, when driving at high speeds, use the engine power ENGPower (low output point) with low power generation efficiency such as low torque and low rotation so that the power generated by the power generator motor MG1Power is balanced with the power consumption by the drive motor power MG2Power. I have to generate electricity.

  As described above, in the background art, there is useless engine driving time for satisfying the acceleration response request. In particular, the power generation request decreases at a high SOC and a high vehicle speed, but the engine cannot be stopped due to an acceleration response request, which consumes extra fuel. In addition, since both the engine and the generator generate power at operating points where the power generation efficiency is low, there is a problem that fuel efficiency is further deteriorated.

[Problem solving means and problem solving action]
The present inventors have paid attention to the above problem, and provided an engine stop time under conditions where it is not necessary to consider the problem of the acceleration response while responding to the acceleration response request. In other words, as a means for solving the problem, during traveling in the "engine stop mode", the vehicle position information and traveling estimation information for estimating a traveling mode ahead from the current position of the vehicle are obtained. Based on the vehicle position information and the travel estimation information, a required driving force required when the vehicle travels from the current location along the road to be traveled is predicted. When the required driving force is predicted to be larger than the threshold value, the engine 1 is switched from the “engine stop mode” to the “engine power generation mode” in which the engine 1 is started and the power generation motor 2 generates power. When the required driving force is predicted to be smaller than the threshold value, a control method for maintaining the “engine stop mode” is employed.

  That is, if the required driving force is predicted to be smaller than the threshold during the series running, the "engine stop mode" is maintained, thereby suppressing unnecessary fuel consumption. If the required driving force is predicted to be larger than the threshold during the series running, by switching to the “engine power generation mode”, the maximum torque requested by the power supply from the power generation motor 2 and the battery 8 can be output.

  During high-speed running, as shown in FIG. 8, when the drive motor power MG2Power is constant and there is no acceleration response request, the generator motor power MG1Power (power generation amount) is output by the engine power ENGPower higher than that in FIG. Can be. In other words, power can be generated by using the engine power ENGPower (high output point) with high power generation efficiency such as high torque and high rotation. It should be noted that the battery SOC can be managed by setting the “engine stop mode” when the SOC becomes high, and conversely by setting the engine generation mode when the battery SOC becomes low.

  Further, when switching from the “engine stop mode” to the “engine power generation mode”, the acceleration response request can be satisfied by using the prediction information of the required driving force.

  That is, as shown in the accelerator opening characteristic and the engine speed characteristic in FIG. 9, it is assumed that the engine is started and the driving force is generated after an acceleration request is made by the accelerator depression operation. In this case, an acceleration lag time occurs in which the driving force cannot be generated until the engine start is completed (a front-back G characteristic surrounded by an arrow R in FIG. 9). That is, it is not possible to obtain a vehicle speed characteristic due to a rising vehicle speed that satisfies the acceleration response requirement.

  On the other hand, as shown in the accelerator opening characteristic and the engine speed characteristic in FIG. 10, by using the prediction information of the required driving force, it is possible to start the engine 1 and output the driving force before the acceleration is requested. it can. For this reason, it is possible to eliminate the occurrence of the acceleration lag time during which the driving force cannot be generated until the start of the engine is completed (the front-rear G characteristic surrounded by the arrow S in FIG. 10). That is, it is possible to obtain a vehicle speed characteristic based on the rise of the vehicle speed that satisfies the acceleration response request.

  For this reason, during series running, it is possible to achieve an improvement in fuel efficiency by suppressing unnecessary fuel consumption while satisfying the driver's acceleration response request. Then, during the series running in the “engine power generation mode”, the rotation speed of the engine 1 is set to a region where the power generation efficiency of the power generation motor 2 is high, and when the battery SOC of the battery 8 exceeds the upper limit capacity, the “engine power generation mode” starts. The mode is switched to "engine stop mode". Therefore, it is possible to further improve the fuel efficiency while managing the battery SOC of the battery 8.

[Learning of driver driving preferences for each driving scene]
Driver types vary widely. For example,
(a) A type that overtakes the preceding vehicle on an expressway but does not overtake a preceding vehicle on an ordinary road
(b) A type that does not overtake a preceding vehicle on a highway but overtakes a preceding vehicle on a general road
(c) Overtaking the preceding vehicle on both expressways and general roads
(d) There are types that do not overtake the preceding vehicle on both expressways and general roads.

  On the other hand, in the learning control of the driver's driving preference, the "running scene" and the "drive style with respect to the preceding vehicle" are linked by a combination of the judgment items of the driving environment. It is characterized in that the “pulling-out” of learning is increased by learning driver's driving preferences meticulously by this linking. Hereinafter, the learning operation of the driver's preference for each driving scene will be described based on the flowchart of FIG.

  First, in the flowchart of FIG. 3, the process proceeds from S1 to S2 to S3. At S1, necessary information for the driver driving preference learning control is read. In S2, the driving scene X at that time is determined by a combination of the driving environment determination items. In S3, it is determined whether or not the preceding vehicle exists in front of the own vehicle and the inter-vehicle distance between the own vehicle and the preceding vehicle is equal to or less than a predetermined value. In S3, when it is determined that there is no preceding vehicle ahead of the own vehicle, or when there is a preceding vehicle ahead of the own vehicle, but it is determined that the inter-vehicle distance between the own vehicle and the preceding vehicle exceeds a predetermined value. When it is done, the flow of going from S1 to S2 to S3 is repeated.

  However, when a preceding vehicle exists in front of the own vehicle in S3, and it is determined that the inter-vehicle distance between the own vehicle and the preceding vehicle is equal to or less than a predetermined value, the process proceeds from S3 to S4. In S4, it is determined whether the relative vehicle speed between the own vehicle and the preceding vehicle is equal to or higher than a predetermined vehicle speed, and whether the accelerator opening is equal to or higher than the predetermined opening.

  In the determined section of the driving scene X, the driver's driving preference is to follow the preceding vehicle, and the vehicle follows the preceding vehicle without moving the own vehicle close to the preceding vehicle and without depressing the accelerator. It is assumed that the driving preference is In this case, the process proceeds from S4 to S5 → S8 → S10 → End regardless of how many times the determined traveling scene X is divided. In S5, the number N of times of passing the preceding vehicle is set to N = 0. In S8, it is learned that the driver's driving preference is to follow the front vehicle. In S10, the classification of the running scene X at that time is stored as the learning result as "the front vehicle follower".

  In addition, it is assumed that a driver having a driving preference to follow the preceding vehicle performs an accelerator depressing operation so as to exceptionally bring the own vehicle closer to the preceding vehicle and overtake the preceding vehicle in the determined division of the traveling scene X. I do. In this case, the process proceeds from S4 to S6 → S7 → S8 → S10 → End. That is, if only the passing operation of the front vehicle is performed exceptionally, it is learned in S8 that the driver's driving preference is the front vehicle follower, and in S10, the classification of the running scene X at that time is set as the learning result It is saved as "car follower."

  On the other hand, in the determined category of the driving scene X, the driving preference of the driver is the overtaking front vehicle, and the driving preference is to bring the own vehicle close to the preceding vehicle and perform the accelerator depressing operation to overtake the preceding vehicle. And In this case, once the determined section of the traveling scene X is experienced once, the process proceeds from S4 to S6 → S7 → S8 → S10 → End. In S6, it is determined that the number N of times of passing the preceding vehicle has not reached the continuous experience number threshold Nth, and in S7, the number N of experiences of passing the preceding vehicle is set to N = 1. That is, when the number N of times of passing the front vehicle is only one, it is learned in S8 that the driver's driving preference is the front vehicle follower, and in S10, the classification of the running scene X at that time is set as a learning result. It is saved as "Front car follower."

  Thereafter, when the vehicle again encounters the same scene in the same section and experiences the second time, the process proceeds from S4 to S6 → S7 → S8 → S10 → End. In S6, it is determined that the number N of times of passing the preceding vehicle has not reached the continuous experience number threshold Nth, and in S7, the number of experiences N of passing the preceding vehicle is set to N = 2. That is, when the number N of times of passing vehicle passing experience is 2 and Nth ≧ 3 is set, it is learned in S8 that the driver's driving preference is the following vehicle driving preference, and in S10, the driving at that time is performed. In the section of scene X, the result of learning is stored as "front vehicle follower".

  Thereafter, when the number of experiences of encountering the traveling scene of the same section reaches a plurality of times, and it is determined in S6 that the number N of times of passing the front vehicle has reached the threshold Nth of the number of consecutive experiences, the process proceeds from S4 to S6 → S9 → S10. → Proceed to the end. In S10, following the learning in S9 that the vehicle is ahead of the front vehicle, the result of learning is stored in the section of the traveling scene X at that time as "Learning vehicle in front".

  As described above, in the driver driving preference learning control, the opportunity to select the “engine stop mode” is increased as much as possible based on the fact that the driver driving preference is that of following the front vehicle. However, if it is presumed that the front vehicle follower is uniformly based only on the road type, and if the driver's driving preference is that of the front vehicle, the driver may not be able to respond to the acceleration request depending on the driving scene. It was divided into a plurality according to the combination of the judgment items of the driving environment. Then, it is learned in detail whether the driver's driving preference is “front vehicle follower” or “front vehicle overtaker” for each section of the running scene.

[Control of engine power generation / stop at high vehicle speed]
The engine power generation / stop control at a high vehicle speed is characterized in that the driving environment information and the learning result of the driver's driving preference are reflected in the control. Hereinafter, the engine power generation / stop control operation at the time of high vehicle speed will be described based on the flowchart of FIG.

  When the vehicle speed VSP is lower than the predetermined vehicle speed, the flow of S21 → S22 → End is repeated in the flowchart of FIG. 6, and in S22, switching control in the normal control mode shown in FIG. 2 is executed.

  If the vehicle speed VSP is equal to or higher than the predetermined vehicle speed and the vehicle is running in the series in the “engine stop mode”, the process proceeds to S21 → S23 → S24 → S25 → S26 in the flowchart of FIG. In S24, the current location information of the own vehicle is obtained. In S25, traveling environment information along the road to be traveled ahead of the current position of the vehicle is obtained. In S26, it is determined whether or not the magnitude of the change in the traveling load based on the traveling environment information when the vehicle travels from the current location along the road to be traveled is less than the threshold.

  When it is determined in S26 that the magnitude of the change in running load ≧ the threshold value, the process proceeds from S26 to S27. In S27, following the determination of NO in S26, it is determined whether or not the vehicle has arrived at a position a predetermined distance before the acceleration event in which the change in running load becomes large. While the vehicle does not reach the position a predetermined distance before the acceleration event, the flow of the sequence of S24 → S25 → S26 → S27 is repeated. On the other hand, if it is determined in S27 that the vehicle has reached the position a predetermined distance before the acceleration event, the process proceeds from S27 to S31 → S34 → End. In S31, the engine 1 is started from the "engine stop mode" and switched to the "engine power generation mode" in which the power is generated by the power generation motor 2. In S34, the series running is performed in the “engine power generation mode” in which the rotation speed of the engine 1 is set to a region where the power generation efficiency of the power generation motor 2 is high.

  On the other hand, if it is determined in S26 that the magnitude of the change in the running load is smaller than the threshold value, the process proceeds from S26 to S28 → S29 → S30. In S28, the following distance information between the own vehicle and the surrounding vehicles is obtained. In S29, the learning result of the driver's driving preference is obtained for each section of the driving scene, and the driving force change amount is predicted based on the learning result of the driver's driving preference. In S30, it is determined whether the predicted driving force change amount is equal to or less than a threshold value.

  If it is determined in S30 that the driving force change amount ≦ the threshold value, the process proceeds from S30 to S32 → S34 → End. In S32, the "engine stop mode" is maintained. In S34, the vehicle runs in series by continuing the “engine stop mode”.

  On the other hand, if it is determined in S30 that the driving force change amount> the threshold value, the process proceeds from S30 to S31 → S34 → End. In S31, the engine 1 is started from the "engine stop mode" and switched to the "engine power generation mode" in which the power is generated by the power generation motor 2. In S34, the series running is performed in the “engine power generation mode” in which the rotation speed of the engine 1 is set to a region where the power generation efficiency of the power generation motor 2 is high.

  If the vehicle speed VSP is equal to or higher than the predetermined vehicle speed and the vehicle is running in the series in the “engine power generation mode”, the process proceeds to S21 → S23 → S33 in the flowchart of FIG. In S33, it is determined whether another engine operating condition is satisfied. When it is determined in S33 that other engine operating conditions are satisfied, for example, when the battery SOC has not reached the upper limit threshold, the process proceeds from S33 to S31 → S34 → End. In S31, the "engine power generation mode" is maintained. In S34, the series running is performed in the “engine power generation mode” in which the rotation speed of the engine 1 is set to a region where the power generation efficiency of the power generation motor 2 is high.

  On the other hand, when it is determined in S33 that other engine operating conditions are satisfied, for example, when the SOC of the battery 8 increases due to the series running in the “engine power generation mode” and the battery SOC becomes equal to or higher than the upper limit threshold, the process proceeds from S33 to S32 → S34 → proceed to the end. In S32, the mode is switched from the "engine power generation mode" to the "engine stop mode". In S34, the vehicle runs in series in the "engine stop mode".

  As described above, the engine power generation / stop control at a high vehicle speed is performed by an acceleration event (such as an upward gradient) in which the magnitude of a change in the traveling load when the vehicle travels from the current location along the planned road is equal to or greater than the threshold. When the vehicle is present on the planned road, the mode selection based on the traveling environment information has priority. That is, when it is determined that the vehicle has reached the position a predetermined distance before the acceleration event, the engine 1 is started from the “engine stop mode” and switched to the “engine power generation mode” in which the power generation motor 2 generates power.

  When the magnitude of the change in the traveling load when the vehicle travels from the current location along the road to be traveled is less than the threshold value (e.g., a flat road or a downward slope), the "engine stop mode" is not necessarily maintained. The mode is selected by reflecting the learning result of the driver's driving preference. That is, the learning result of the driver's driving preference is obtained for each section of the driving scene, and the driving force change amount is predicted based on the learning result of the driver's driving preference. The "stop mode" is maintained. However, if it is determined that “driving force change amount> threshold”, the engine 1 is started from “engine stop mode” and switched to “engine power generation mode” in which power is generated by the power generation motor 2. As described above, when the learning result of the driver's driving preference is that of passing the front vehicle, an opportunity to select the “engine power generation mode” is given even though the magnitude of the change in the traveling load is less than the threshold value. .

  As described above, the control method and the control device of the series hybrid vehicle according to the first embodiment have the following effects.

(1) Equipped with engine 1, generator motor 2, drive motor 3 and battery 8,
A hybrid vehicle (series hybrid vehicle) that switches between an engine stop mode in which power is supplied to the drive motor 3 from the battery 8 and an engine power generation mode in which power is supplied to the drive motor 3 from the battery 8 and the power generation motor 2 during series running. In the control method,
During traveling in the engine stop mode, the vehicle obtains traveling position information and traveling estimation information (traveling environment information) for estimating a traveling mode ahead from the current position of the vehicle,
Based on the vehicle position information and the travel estimation information, a required driving force (a magnitude of a change in travel load) required when the vehicle travels along the planned road from the current location is predicted,
If the required driving force is predicted to be larger than the threshold value, the engine 1 is switched from the engine stop mode to the engine power generation mode in which the power is generated by the generator motor 2. If the required driving force is predicted to be smaller than the threshold value, the engine is stopped. The mode is maintained (FIG. 6).
Therefore, it is possible to provide a method of controlling a hybrid vehicle (series hybrid vehicle) that achieves improved fuel economy by suppressing wasteful fuel consumption while satisfying the driver's acceleration response requirement during series running.

(2) As traveling estimation information, obtain traveling environment information ahead of the current position of the vehicle,
The required driving force is predicted by the magnitude of the change in the traveling load based on the traveling environment information when the vehicle travels from the current location along the road to be traveled (FIG. 6).
Therefore, it is possible to predict the required driving force when the vehicle travels from the current position along the road to be traveled based on the magnitude of the change in the traveling load based on the traveling environment information ahead of the current position of the vehicle.

(3) Learn whether the driver's driving preference is front car overtaking or front car following.
Obtain the learning result of driver driving preferences as travel estimation information,
The required driving force is predicted by adding the learning result of the driver's driving preference to the magnitude of the change in the traveling load when the vehicle travels from the current location along the road to be traveled (FIG. 3).
For this reason, it is possible to add the prediction of the required driving force based on the learning result of the driver's driving preference to the prediction of the required driving force based on the magnitude of the change in the traveling load, and to select the mode between the engine stop mode and the engine power generation mode. Furthermore, by adding driver driving preferences to the driving environment information, it is possible to prepare for driver intervention during automatic driving. That is, by predicting a scene in which the driver is likely to intervene from the driver's driving preferences during automatic driving and driving the engine 1 in advance, an acceleration response can be ensured.

(4) During traveling with the engine stop mode selected, if it is determined that the magnitude of the traveling load change is larger than the threshold, the vehicle has reached a position a predetermined distance before the acceleration event in which the traveling load change becomes large. Judge whether or not
When the vehicle reaches a predetermined distance before the acceleration event, the engine 1 is started and switched to the engine power generation mode in which the power is generated by the power generation motor 2 irrespective of the learning result of the driver's driving preference (FIG. 6).
Therefore, if there is an acceleration event on the road to be traveled while the vehicle is running with the engine stop mode selected, the engine 1 is operated before the vehicle arrives at the acceleration event, thereby ensuring acceleration with no acceleration lag. can do.

(5) If the magnitude of the change in the traveling load is determined to be equal to or less than the threshold during traveling while selecting the engine stop mode, the information on the inter-vehicle distance between the own vehicle and the surrounding vehicles is obtained,
If the preceding vehicle is present within a predetermined distance, if the driver's driving preference is that of the preceding vehicle, the mode is switched to the engine power generation mode in which the engine 1 is started and the generator motor 2 is used to generate power. If there is, the engine stop mode is maintained (FIG. 6).
Therefore, even if the engine stop mode is selected if the determination is based on the magnitude of the change in the traveling load, the engine power generation mode is selected by adding the prediction of the driver required driving force based on the learning result of the driver's driving preference. can do.

(6) During series running in the engine power generation mode, the rotation speed of the engine 1 (engine rotation speed Ne) is set to a region where the power generation efficiency of the power generation motor 2 is high,
When the charge capacity (battery SOC) of the battery 8 exceeds the upper limit capacity, the mode is switched from the engine power generation mode to the engine stop mode (FIG. 8).
For this reason, during the series running in the engine power generation mode, the fuel consumption performance can be improved while managing the charge capacity (battery SOC) of the battery 8 as compared with the case where the power generation amount is not necessary in terms of power balance.

(7) During the series running, when the vehicle speed VSP is equal to or higher than the predetermined vehicle speed, switching control between the engine stop mode and the engine power generation mode based on the prediction of the required driving force is executed (FIG. 6).
Therefore, when the vehicle speed VSP, which had to keep the engine 1 running even when power generation is not necessary in the power balance, is equal to or higher than the predetermined vehicle speed, the fuel consumption is reduced by suppressing unnecessary fuel consumption while satisfying the driver's acceleration response request. Improved performance can be achieved.

(8) Equipped with engine 1, generator motor 2, drive motor 3 and battery 8,
A controller (vehicle control module 20) that switches between an engine stop mode in which power is supplied to the drive motor 3 from the battery 8 and an engine power generation mode in which power is supplied to the drive motor 3 from the battery 8 and the power generation motor 2 during series running. In the control device of the equipped hybrid vehicle (series hybrid vehicle),
The controller (vehicle control module 20)
While traveling in the engine stop mode, an information obtaining unit 20a that obtains own vehicle position information and travel estimation information for estimating a previous travel mode from the current position of the own vehicle,
A required driving force prediction unit 20b for predicting a required driving force required when the vehicle travels from the current location along the road to be traveled, based on the vehicle position information and the travel estimation information;
When the required driving force is predicted to be larger than the threshold value, the engine 1 is switched from the engine stop mode to the engine power generation mode in which the engine 1 is started to generate power by the power generation motor 2. When the required driving force is predicted to be smaller than the threshold value, the engine is stopped. And an engine power generation / stop control unit 20c that maintains the mode (FIG. 2).
Therefore, it is possible to provide a control device for a hybrid vehicle (series hybrid vehicle) that achieves improvement in fuel efficiency by suppressing unnecessary fuel consumption while satisfying a driver's acceleration response request during series running.

  The control method and the control device of the hybrid vehicle according to the present disclosure have been described based on the first embodiment. However, the specific configuration is not limited to the first embodiment, and changes and additions of the design are permitted without departing from the gist of the invention according to each claim of the claims.

  In the first embodiment, while traveling in the engine stop mode, the information acquisition unit 20a acquires the vehicle position information, the traveling environment information for estimating the traveling mode ahead of the current position of the vehicle, and the learning result information of the driver's driving preference. Examples have been given. However, the information obtaining unit may obtain the position information, the vehicle speed information, and the accelerator opening degree information of the preceding vehicle traveling a predetermined distance ahead of the own vehicle by inter-vehicle communication. It is possible to know the acceleration section and the deceleration section when traveling ahead. Further, the information obtaining unit may be configured to obtain the generated vehicle speed profile information when the vehicle speed profile is generated in advance in the automatic driving vehicle along the target traveling route. Further, the information acquisition unit may be an example of acquiring the traveling mode storage information in a case where the user has experience traveling on the same road in the past and the traveling mode at that time is stored. In short, the information is not limited to the traveling environment information and the learning result information of the driver's driving preference as long as the information can estimate the traveling mode ahead of the current position of the own vehicle.

  In the first embodiment, the required driving force prediction unit 20b is required when the vehicle travels from the current location along the road to be traveled based on the vehicle position information, the traveling environment information, and the learning result information of the driver's driving preference. An example has been shown in which the magnitude of the change in running load and the amount of change in driving force are predicted. However, the required driving force prediction unit may predict the required driving force itself, or may predict the amount of change in the accelerator opening. In short, as long as a value corresponding to the required driving force is predicted, it is not limited to the magnitude of the running load change or the driving force change amount.

  In the first embodiment, the example has been described in which, when the vehicle speed VSP is equal to or higher than the predetermined vehicle speed during the series running, the switching control between the engine stop mode and the engine power generation mode based on the prediction of the required driving force is executed. However, during the series running, the switching control between the engine stop mode and the engine power generation mode based on the prediction of the required driving force is not limited to the high vehicle speed region where the vehicle speed is equal to or higher than the predetermined vehicle speed, and may be executed in the entire vehicle speed region. .

  In the first embodiment, an example is described in which the control method and the control device according to the present disclosure are applied to a series hybrid vehicle that runs in series using an engine as a power source for power generation and a drive motor as a driving source for traveling. However, the control method and control device of the present disclosure can also be applied to a parallel hybrid vehicle having a series hybrid traveling mode.

Reference Signs List 1 engine 2 generator motor 3 drive motor 4 gear box 5L, 5R front drive shaft 6L, 6R front wheel (drive wheel)
7 generator motor / drive motor inverter 8 battery 20 vehicle control module (controller)
20a Information obtaining unit 20b Required driving force prediction unit 20c Engine power generation / stop control unit 20d Driver driving preference learning unit 21 Engine controller 22 Motor generator controller 23 Battery controller 24 Navigation control unit 25 Driving support control unit 26 CAN communication line

Claims (8)

Equipped with engine, generator motor, drive motor and battery,
An engine stop mode in which power is supplied to the drive motor from the battery during series running, and a control method for a hybrid vehicle that switches between an engine power generation mode in which power is supplied to the drive motor from the battery and the power generation motor,
During traveling in the engine stop mode, the vehicle obtains traveling estimation information for estimating a traveling mode ahead from the current position of the own vehicle position information and the own vehicle,
Based on the vehicle position information and the travel estimation information, predict the required driving force required when the vehicle travels along the planned road from the current location,
If the required driving force is predicted to be larger than the threshold, the engine is switched from the engine stop mode to the engine power generation mode in which the engine is started and the power generation motor generates power, and the required driving force is predicted to be smaller than the threshold. And maintaining the engine stop mode. The control method for a hybrid vehicle according to claim 1,
As the travel estimation information, obtain travel environment information ahead of the current location of the vehicle,
A method for controlling a hybrid vehicle, comprising: predicting the required driving force based on a magnitude of a change in a traveling load based on the traveling environment information when the own vehicle travels along a planned road from a current location. The control method for a hybrid vehicle according to claim 2,
Learn whether the driver's driving preference is front car overtaking or front car following,
As the travel estimation information, a learning result of the driver driving preference is obtained,
A hybrid vehicle control method comprising: predicting the required driving force by adding a learning result of the driver's driving preference to a magnitude of a change in a traveling load when the vehicle travels along a planned road from a current position. Method. The control method for a hybrid vehicle according to claim 3,
If the magnitude of the change in the traveling load is determined to be larger than the threshold during traveling with the engine stop mode selected, whether or not the vehicle has reached a position a predetermined distance before the acceleration event in which the variation in the traveling load is large. Judge
When the vehicle reaches a predetermined distance before the acceleration event, regardless of the learning result of the driver's driving preference, the engine is started and the mode is switched to the engine power generation mode in which power is generated by the power generation motor. The control method for a hybrid vehicle according to claim 4,
During traveling while selecting the engine stop mode, when it is determined that the magnitude of the traveling load change is equal to or less than the threshold, to obtain inter-vehicle distance information between the own vehicle and the surrounding vehicles,
When the preceding vehicle is present within a predetermined distance, if the driver's driving preference is that of passing the front vehicle, the driving mode is switched to the engine power generation mode in which the engine is started and the electric power is generated by the power generation motor. , Wherein the engine stop mode is maintained. A control method for a hybrid vehicle according to any one of claims 1 to 5,
During series running in the engine power generation mode, the number of revolutions of the engine is set in a region where the power generation efficiency of the power generation motor is high,
A control method for a hybrid vehicle, comprising: switching from the engine power generation mode to the engine stop mode when a charge capacity of the battery exceeds an upper limit capacity. A control method for a hybrid vehicle according to any one of claims 1 to 6,
A control method for a hybrid vehicle, comprising: performing switching control between the engine stop mode and the engine power generation mode based on a prediction of a required driving force when a vehicle speed is equal to or higher than a predetermined vehicle speed during series running. Equipped with engine, generator motor, drive motor and battery,
A control device for a hybrid vehicle including a controller that switches between an engine stop mode in which power is supplied to the drive motor from the battery during series running and an engine power generation mode in which power is supplied to the drive motor from the battery and the power generation motor. At
The controller is
While traveling in the engine stop mode, an information obtaining unit that obtains travel position estimation information for estimating a travel mode ahead of the vehicle from current position of the vehicle position information,
Based on the vehicle position information and the travel estimation information, a required driving force prediction unit that predicts a required driving force required when the vehicle travels from the current location along the planned road,
If the required driving force is predicted to be larger than the threshold, the engine is switched from the engine stop mode to the engine power generation mode in which the engine is started and the power generation motor generates power, and the required driving force is predicted to be smaller than the threshold. A control device for a hybrid vehicle, comprising: an engine power generation / stop control unit that maintains the engine stop mode.