Vehicle control devices

Abstract

The present invention relates to a vehicle control device. The vehicle includes an internal combustion engine and a rotating electrical machine connected to the internal combustion engine in a power-transmittable manner. When a torque reduction request is issued corresponding to the vehicle state, the vehicle control device can perform torque reduction by performing ignition delay control to delay the ignition timing of the internal combustion engine and regeneration control based on regeneration of the rotating electrical machine. When the actual torque of the rotating electrical machine under regeneration control is insufficient for the torque reduction request, the vehicle control device performs torque reduction by retarding the ignition timing of the internal combustion engine to the amount of the shortfall.

Description

Technical Field

[0001] The present invention relates to a control device for a vehicle. Background Art

[0002] Japanese Patent Application Laid-Open No. 2006-159929 discloses a control device for a vehicle equipped with an internal combustion engine and a rotating electrical machine. The device executes ignition retardation control, which retards the ignition timing of the internal combustion engine, and regeneration control, which utilizes the rotating electrical machine for regeneration, during torque-down control. The control also controls the torque distribution between the ignition retardation control and the regeneration control. In the configuration described in Japanese Patent Application Laid-Open No. 2006-159929, during torque-down control, the torque-down amount is preferentially allocated to the internal combustion engine, with the remaining amount allocated to the rotating electrical machine. Summary of the Invention

[0003] Torque-down control includes, for example, high-response torque-down control for vibration reduction control when switching from accelerator-off to accelerator-on. High-response torque-down control uses an internal combustion engine as the control target, and torque reduction is achieved by retarding the engine's ignition timing. Ignition timing control is highly responsive, enabling high-response control. However, torque-down control caused by ignition retardation degrades the thermal efficiency of the internal combustion engine, achieving torque reduction. Therefore, to improve fuel economy, the use of rotating electric machines in high-response torque-down control is a possibility.

[0004] However, rotating electric machines experience a response delay between the requested torque output and the actual torque output. Consequently, when using the rotating electric machine for regeneration during high-response torque-down control, coordination with the internal combustion engine is lost, preventing control according to the requested torque-down amount, potentially leading to shock.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle control device capable of suppressing the occurrence of shock during torque-down and improving fuel economy.

[0006] The present invention is a control device for a vehicle, wherein the vehicle comprises an internal combustion engine and a rotating electric machine connected to the internal combustion engine in a manner capable of dynamically transmitting power. When there is a torque reduction requirement corresponding to the vehicle state, torque reduction can be achieved by ignition delay control for delaying the ignition timing of the internal combustion engine and regeneration control based on the regeneration of the rotating electric machine. The control device of the vehicle is characterized in that when the actual torque of the rotating electric machine based on the regeneration control is insufficient relative to the torque reduction requirement, the insufficient torque is reduced by delaying the ignition timing of the internal combustion engine.

[0007] According to this configuration, the ignition timing is controlled based on the actual torque of the rotating electrical machine during torque down, thereby taking the response delay of the rotating electrical machine into account. This can suppress the occurrence of shock during torque down and improve fuel economy.

[0008] Alternatively, a guard value may be set for gradually changing the regenerative torque output from the rotating electrical machine through the regenerative control. The guard value is a value that changes according to the vehicle speed and is set such that the higher the vehicle speed, the greater the change in regenerative torque per unit time.

[0009] According to this configuration, by providing the gradual change guard value corresponding to the vehicle speed for the regenerative torque of the rotating electric machine, it is possible to prevent the occurrence of a shock caused by a response delay of the rotating electric machine during torque reduction.

[0010] In addition, the vehicle may also include a coupling device arranged in the power transmission path between the rotating motor and the drive wheel, and the protection value is a value that changes according to the coupling state of the coupling device, and is set in such a way that the change in regenerative torque per unit time is large when the coupling device is not in the coupling state.

[0011] According to this configuration, by providing the gradual change guard value corresponding to the engagement state of the engagement device for the regenerative torque of the rotating electrical machine, it is possible to prevent the occurrence of a shock caused by a response delay of the rotating electrical machine during torque reduction.

[0012] In addition, the vehicle may further include a torque converter arranged between the internal combustion engine and the automatic transmission, the engagement device may be a lockup clutch arranged in the torque converter, and the protection value may be set in such a manner that the regenerative torque change per unit time is large when the lockup clutch is not in a directly connected state.

[0013] According to this configuration, by providing the gradual change guard value corresponding to the engagement state of the lockup clutch for the regenerative torque of the rotating electric machine, it is possible to prevent the occurrence of a shock caused by a response delay of the rotating electric machine during torque reduction.

[0014] In the present invention, the ignition timing is controlled based on the actual torque of the rotating electrical machine during torque down, thereby taking the response delay of the rotating electrical machine into account. This can suppress the occurrence of shock during torque down and improve fuel economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like numerals represent like elements, and in which:

[0016] Figure 1It is an explanatory diagram showing a schematic configuration of a vehicle in the embodiment.

[0017] Figure 2 : is a flowchart showing the flow of torque-down control.

[0018] Figure 3 Graph showing the relationship between the gradient protection value and the vehicle speed.

[0019] Figure 4 This is a time chart for explaining changes in the vehicle state when the torque-down control in the first embodiment is executed.

[0020] Figure 5 This is a time chart for explaining changes in the vehicle state when the torque-down control in Comparative Example 1 is executed.

[0021] Figure 6 This is a time chart for explaining changes in the vehicle state when the torque-down control in the second embodiment is executed.

[0022] Figure 7 This is a time chart for explaining changes in the vehicle state when the torque-down control in Comparative Example 2 is executed.

[0023] Figure 8 This is a time chart for explaining changes in the vehicle state when the torque-down control in the third embodiment is executed.

[0024] Figure 9 This is a time chart for explaining changes in the vehicle state when the torque-down control in Comparative Example 3 is executed. DETAILED DESCRIPTION

[0025] Hereinafter, a vehicle control device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited to the embodiment described below.

[0026] Figure 1 This is an explanatory diagram showing the schematic configuration of a vehicle according to an embodiment. Vehicle 1 includes an engine 2, drive wheels 3, and a power transmission device 10 provided in a power transmission path between the engine 2 and the drive wheels 3. Power transmission device 10 includes a torque converter 11, an automatic transmission 12, a differential gear 13, and a drive shaft 14. Power output from engine 2 is sequentially transmitted to the torque converter 11, the automatic transmission 12, the differential gear 13, and the drive shaft 14, and then to the drive wheels 3.

[0027] The engine 2 is a power source for traveling and is a well-known internal combustion engine such as a gasoline engine or a diesel engine. The operation of the engine 2, such as fuel injection and ignition timing, is controlled by an electronic control unit 20. The detailed structure of the electronic control unit 20 will be described later.

[0028] The torque converter 11 is a fluid transmission device arranged in the power transmission path between the engine 2 and the automatic transmission 12. The torque converter 11 includes a pump impeller 11a as an input-side rotating element, a turbine 11b as an output-side rotating element, and a lock-up clutch LC as a direct-connection clutch that selectively connects the pump impeller 11a and the turbine 11b. The pump impeller 11a is connected to the crankshaft 2a of the engine 2. The turbine 11b is connected to the input shaft of the automatic transmission 12. The lock-up clutch LC is a friction engagement device that can be in an engaged state, a semi-engaged state, and a released state. When the lock-up clutch LC is in the engaged state, the friction engagement elements are fully engaged with each other, resulting in a direct-connection state in which the front cover, which is the input element on the engine 2 side, and the turbine shaft, which is the output element on the automatic transmission 12 side, are directly connected. In the direct-connection state, the pump impeller 11a and the turbine 11b rotate integrally.

[0029] The power transmission device 10 includes a mechanical oil pump connected to the pump impeller 11a of the torque converter 11. This mechanical oil pump is driven by the engine 2 and discharges hydraulic oil drawn from the oil pan. The hydraulic oil discharged from the mechanical oil pump is used to control the speed change of the automatic transmission 12 and to switch the operating state of the lockup clutch LC.

[0030] The automatic transmission 12 is a stepped automatic transmission that forms part of the power transmission path between the engine 2 and the drive wheels 3. For example, the automatic transmission 12 is a multi-speed planetary transmission in which multiple planetary gears are arranged on the same axis. Furthermore, the output gear, which serves as the output element of the automatic transmission 12, is connected to the differential gear 13 via a countershaft gear mechanism. In the vehicle 1, the automatic transmission 12, the countershaft gear mechanism, and the differential gear 13 are housed within a transaxle case mounted on the vehicle body.

[0031] The automatic transmission 12 is equipped with a plurality of engagement devices including clutches and brakes. The engagement devices are hydraulic friction engagement devices, and the torque capacity varies according to the hydraulic pressure output as the engagement pressure from a plurality of solenoid valves included in the hydraulic control circuit, thereby switching the respective operating states. In the automatic transmission 12, the rotating elements in the plurality of planetary gear devices are connected or released, or selectively fixed to each other by the engagement devices. Furthermore, the automatic transmission 12 is capable of selectively forming a plurality of gear stages with different gear ratios by selectively engaging any one of the engagement devices according to the driver's accelerator operation, vehicle speed, etc. by the electronic control unit 20. For example, in the automatic transmission 12, each gear stage (each gear stage) of the eight forward gear stages from the first speed gear stage to the eighth speed gear stage and the reverse gear stage is selectively formed.

[0032] Vehicle 1 also includes a motor 30 as a power source independent of engine 2. Motor 30 is an electric generator (MG) capable of functioning as both an electric motor and a generator. Motor 30 is a well-known rotating electrical machine. Furthermore, motor 30 is electrically connected to a battery via an inverter. The battery is a secondary battery such as a lithium-ion battery. Electricity generated by motor 30 can be stored in the battery. Furthermore, by supplying the electric power stored in the battery to motor 30, motor 30 can be driven.

[0033] Furthermore, the motor 30 is connected to the engine 2 via a transmission belt 40 for power transmission. The transmission belt 40 is looped around a pair of pulleys consisting of a first pulley provided on the crankshaft 2a of the engine 2 and a second pulley provided on the output shaft 31 of the motor 30. When the motor 30 functions as an electric motor, the output torque (motor torque) of the motor 30 is input to the crankshaft 2a of the engine 2 via the transmission belt 40. This allows the motor 30 to function as a starter when starting the engine 2 and as a hybrid motor to assist the engine 2 while the vehicle 1 is traveling. On the other hand, when the motor 30 functions as a generator, for example, the output torque (engine torque) of the engine 2 is input to the output shaft 31 of the motor 30 via the transmission belt 40. Thus, the motor 30 generates electricity (regeneration) based on the rotation of the output shaft 31. In other words, the motor 30 functions as an AC generator. This motor 30 is not limited to being powered by the engine 2; in situations such as deceleration regeneration during vehicle 1 driving, it can also perform regeneration by rotating the output shaft 31 due to external force from the drive wheels 3.

[0034] The vehicle 1 also includes an electronic control unit 20 as a controller for controlling the vehicle 1. The electronic control unit 20 is an ECU configured to include a microcomputer including, for example, a CPU, RAM, ROM, and an input / output interface. The electronic control unit 20 is a control unit for the vehicle 1.

[0035] Signals from various sensors mounted on the vehicle 1 are input to the electronic control unit 20. Examples of the various sensors include a vehicle speed sensor that detects the vehicle speed, an engine speed sensor that detects the engine speed of the engine 2, an input speed sensor that detects the speed of the input shaft of the automatic transmission 12, an output speed sensor that detects the speed of the output gear of the automatic transmission 12, an accelerator opening sensor that detects the accelerator opening, which is the amount of accelerator pedal operation, a throttle opening sensor that detects the throttle opening, which is the opening of the electronic throttle, an air flow sensor that detects the amount of intake air supplied to the cylinders of the engine 2, a brake stroke sensor that detects the amount of brake pedal operation, and a gear position sensor that detects the operating position of a shift lever.

[0036] The electronic control unit 20 controls the vehicle 1 by executing, for example, drive control of the engine 2, speed control of the automatic transmission 12, and drive control of the motor 30 based on input signals from various sensors. The electronic control unit 20 outputs command signals to various control targets mounted on the vehicle 1. For example, during engine startup, the electronic control unit 20 outputs a command signal to the motor 30, causing the motor 30 to crank the engine 2, thereby starting the engine 2.

[0037] Furthermore, when controlling the drive of engine 2, the electronic control unit 20 outputs a command signal for controlling the ignition timing of engine 2 to engine 2. The throttle opening, fuel injection amount, ignition timing, and other aspects of engine 2 are electrically controlled by the electronic control unit 20. The electronic control unit 20 calculates the required driving force (required torque) based on the accelerator opening and vehicle speed and sets an engine target torque that will produce this required driving force. The electronic control unit 20 then controls the opening and closing of the electronic throttle valve using the throttle actuator, controls the fuel injection amount using the fuel injection device, and controls the ignition timing using the ignition device to produce this target engine torque.

[0038] Furthermore, when regeneration control of motor 30 is executed, a command signal for controlling the regenerative torque is output from electronic control unit 20 to motor 30. Motor 30 can perform regeneration by outputting negative torque (torque acting in the negative direction) while output shaft 31 is rotating in the positive direction. For example, if the accelerator pedal is released while vehicle 1 is traveling, deceleration regeneration control is executed to decelerate vehicle 1, allowing regeneration to occur using motor 30. Alternatively, regeneration can be performed using torque transmitted from engine 2 to motor 30 while engine 2 is operating.

[0039] The electronic control unit 20 also performs torque-down control, which reduces torque compared to the torque requested based on the accelerator opening. In this case, the electronic control unit 20 determines whether there is a request to reduce torque relative to the requested torque corresponding to the accelerator opening (a torque-down request). If there is a torque-down request, the electronic control unit 20 performs torque-down control. When torque-down control is executed, the input torque of the automatic transmission 12 is reduced compared to the accelerator opening request.

[0040] Torque-down control includes ignition retard control, which retards the ignition timing of the engine 2, and regeneration control, which performs regeneration using the motor 30. Specifically, the electronic control unit 20 executes both ignition retard control and regeneration control as part of the torque-down control. Therefore, when executing torque-down control, the electronic control unit 20 outputs a command signal to the engine 2 for controlling the ignition timing and a command signal to the motor 30 for controlling the motor torque (regeneration torque).

[0041] Furthermore, when a torque reduction request is made, the electronic control unit 20 transmits the torque reduction request as a regeneration request to the motor 30. At this point, the electronic control unit 20 calculates the actual torque, taking into account the response delay of the motor 30. The electronic control unit 20 compares the actual torque of the motor 30 during regeneration control with the torque reduction request to determine whether the actual torque meets the request. Furthermore, if the actual torque of the motor 30 does not meet the request—that is, if the actual torque of the motor 30 is insufficient for the torque reduction request—the electronic control unit 20 reduces the torque by the amount of the shortfall by retarding the ignition timing of the engine 2. In other words, the shortfall is compensated by ignition retardation control. Since the actual torque of the motor 30 includes a response delay, the electronic control unit 20 monitors the actual torque of the motor 30 while controlling the ignition timing of the engine 2, enabling coordination between the engine 2 and the motor 30 during torque reduction.

[0042] Figure 2 : is a flowchart showing the flow of torque-down control. Figure 2 The control shown is performed by the electronic control unit 20 .

[0043] The electronic control unit 20 calculates the required torque A corresponding to the accelerator opening (step S101). In step S101, the required torque A is calculated based on the accelerator opening and the vehicle speed. It should be noted that in this description, the "required torque corresponding to the accelerator opening" may be referred to as "accelerator opening required torque," "accelerator opening request," or simply "required torque."

[0044] The electronic control unit 20 outputs an instruction to control the ratio of the amount of air to the amount of fuel supplied to the cylinders of the engine 2 (step S102). In step S102, the ratio of the amount of air to the amount of fuel, that is, the air-fuel ratio of the mixture, is controlled so that the engine torque becomes the indicated torque. In addition, in step S102, the required torque A calculated in step S101 is set as the indicated torque. Furthermore, the electronic control unit 20 outputs a command signal for controlling the amount of intake air and a command signal for controlling the amount of fuel injection to the engine 2 so that the engine torque becomes the indicated torque (=required torque A), thereby controlling the amount of intake air and the amount of fuel injection.

[0045] The electronic control unit 20 then calculates the base ignition timing a (step S103). In step S103, the base ignition timing a is calculated based on the engine speed and the engine load factor. The electronic control unit 20 uses, for example, an ignition timing map stored in memory to set the base ignition timing a using the engine speed and the engine load factor.

[0046] The electronic control unit 20 then determines whether a torque-down request exists (step S104). In step S104, it is determined whether a torque-down request exists relative to the required torque A calculated in step S101. The required torque A is a request based on the driver's accelerator operation. In contrast, the torque-down request is a request that corresponds to the vehicle state. Various requests are input to the electronic control unit 20 depending on the state of the vehicle 1.

[0047] For example, in step S104, the electronic control unit 20 determines that a torque reduction request is present during a so-called chip-in (a situation in which the torque of the engine 2 or motor 30 is suddenly increased). A chip-in is a situation in which the torque of the power source is suddenly increased by the driver's accelerator operation, including a situation in which the accelerator is switched from off to on. Therefore, the electronic control unit 20 can determine that a torque reduction request is present when the accelerator operation speed exceeds a predetermined speed from the accelerator-off state. Furthermore, during a chip-in, the gears in the power transmission device 10 may clash, and therefore, torque reduction control is executed as a vibration reduction control to reduce the sound and vibration caused by the clash.

[0048] If there is no torque-down request (step S104: No), the electronic control unit 20 considers the requested torque A to include the torque-down requested torque B (step S105), sets the requested torque C of the motor 30 (MG requested torque) to zero (step S106), and sets the requested torque of the engine 2 (engine requested torque) to the requested torque A (step S107). If there is no torque-down request, regeneration is not performed using the motor 30, so in step S106, the MG requested torque C is set to zero. Furthermore, to ensure that the requested torque A is satisfied by the engine 2, the electronic control unit 20 sets the requested torque A to the engine requested torque. After executing step S107, the control routine proceeds to step S114.

[0049] If there is a torque-down request (step S104: YES), the electronic control unit 20 calculates the torque-down-included requested torque B (step S108). In step S108, the torque-down-included requested torque B is set to a value smaller than the requested torque A.

[0050] The electronic control unit 20 also calculates the target torque (MG target torque) for the motor 30 (step S109). In step S109, the MG target torque (=BA) is obtained by subtracting the required torque A from the torque-down-included required torque B. The MG target torque is the target value of the regenerative torque when the motor 30 is regenerated in response to the torque-down request. Furthermore, since the required torque A is greater than the torque-down-included required torque B, the MG target torque obtained from "BA" becomes a negative value (negative torque).

[0051] Then, the electronic control unit 20 determines whether the value obtained by subtracting the gradual change protection value from the previous MG required torque is smaller than the MG target torque (step S110). The previous MG required torque is the MG required torque set in the previous control routine. The previous MG required torque is stored in the memory. The gradual change protection value is a protection value determined to gradually change the torque output from the motor 30, and is a positive number. For example, Figure 3 As shown, the ramp guard value varies according to vehicle speed and is set so that the regenerative torque change per unit time increases as vehicle speed increases. Furthermore, in step S110, the electronic control unit 20 determines the ramp guard value based on vehicle speed and subtracts the determined ramp guard value from the previous MG requested torque.

[0052] If the value obtained by subtracting the gradual change guard value from the previous MG required torque is smaller than the MG target torque (step S110 : YES), the electronic control unit 20 sets the MG target torque to the MG required torque C (step S111 ). The MG target torque is the value calculated in step S109 .

[0053] If the value obtained by subtracting the gradual change guard value from the previous MG requested torque is not smaller than the MG target torque (step S110 : NO), the electronic control unit 20 sets the value obtained by subtracting the gradual change guard value from the previous MG requested torque as the MG requested torque C (step S112 ).

[0054] Once the MG required torque C is set, the electronic control unit 20 calculates the engine required torque, or the torque required for the engine 2 (step S113). In step S113, the engine required torque (=BC) is calculated by subtracting the MG required torque C from the torque-down-included required torque B. The electronic control unit 20 sets the value obtained by subtracting the MG required torque C from the torque-down-included required torque B as the engine required torque.

[0055] After the engine torque requirement is set, the electronic control unit 20 calculates the ignition retard amount b for retarding the ignition timing of the engine 2 (step S114). In step S114, the ignition retard amount b is calculated based on the torque-down torque requirement. The torque-down torque requirement is calculated using the equation "A - (BC)".

[0056] For example, when step S114 is executed after step S107, the torque-down required torque B is set to "A" in step S105, and the MG required torque C is set to "0" in step S106. Therefore, substituting these into the relationship "A-(BC)" yields "A-(A-0)", and the torque-down required torque becomes zero. In this case, torque reduction in engine 2 is not required, so the ignition retard amount b is set to zero.

[0057] The electronic control unit 20 then calculates the torque actually output by the motor 30 (actual output torque) D (step S115). In step S115, the actual output torque D (<0) of the motor 30, including the response delay, is calculated. This response delay is the delay from the electronic control unit 20 outputting the command signal to the motor 30 until the motor 30 actually outputs the torque. It should be noted that in this description, "actual output torque" may sometimes be referred to as "MG actual output torque" or "actual torque."

[0058] The electronic control unit 20 determines whether the MG required torque C is not equal to the MG actual output torque D (step S116 ).

[0059] If the MG required torque C is not equal to the MG actual output torque D (step S116: YES), the electronic control unit 20 sets the MG torque correction amount (step S117) by subtracting the MG actual output torque D from the MG required torque C. In step S117, the MG torque is corrected, and the correction amount is set to "CD."

[0060] When the MG required torque C is equal to the MG actual output torque D (step S116: No), the electronic control unit 20 sets the MG torque correction amount to zero (step S118). In step S118, the correction amount is set to "0" because the MG torque is not corrected.

[0061] After the MG torque correction value is set, the electronic control unit 20 calculates the ignition delay correction value c based on the MG torque correction value (step S119). In step S119, the ignition delay correction value is determined based on whether or not the MG torque correction is being used. For example, if the MG torque correction value is "CD" in step S119 following step S117, the ignition delay correction value c is set to satisfy this correction value. On the other hand, if the MG torque correction value is "0" in step S119 following step S118, the ignition delay correction value c is set to zero.

[0062] The electronic control unit 20 determines the ignition timing of the engine 2 based on the base ignition timing a, the ignition retard amount b, and the ignition retard correction amount c (step S120). In step S120, the electronic control unit 20 calculates the ignition timing by subtracting the ignition retard amount b and the ignition retard correction amount c from the base ignition timing a. The electronic control unit 20 then outputs a command signal for controlling the ignition timing to the engine 2 so that the calculated ignition timing is achieved, thereby controlling the ignition timing.

[0063] The electronic control unit 20 then issues a drive instruction for the motor 30 (step S121). In step S121, the MG required torque C is set as the instructed torque of the motor 30. The electronic control unit 20 outputs a command signal for controlling the regenerative torque to the motor 30 to achieve the MG required torque C, thereby controlling the regenerative torque. After executing step S121, the control routine ends.

[0064] Here, refer to Figures 4 to 9 The vehicle state when the torque-down control is executed will be described.

[0065] First, Example 1 will be described. Figure 4 This is a time chart for explaining changes in the vehicle state when the torque-down control in the first embodiment is executed. Figure 5 This is a time chart for explaining changes in the vehicle state when the torque-down control is executed in Comparative Example 1. It should be noted that the comparative example is used in explaining the embodiment.

[0066] The first embodiment performs torque down control as a vibration reduction control when switching from accelerator OFF to accelerator ON (hard pedal vibration reduction control) and performs regeneration control of the motor 30. The first comparative example does not perform regeneration control during torque down control and performs torque down only by ignition retardation. In the first comparative example, since regeneration in the motor is not performed, Figure 5 As shown in FIG, the torque will be lost according to the difference between the accelerator opening requirement and the torque reduction requirement. In contrast, in the first embodiment, since the motor 30 is used for regeneration, as shown in FIG. Figure 4 As shown, the desired torque reduction amount can be regenerated by the motor 30 .

[0067] like Figure 4 As shown, after the accelerator pedal is released, the accelerator opening is abruptly increased by the driver's accelerator pedal depression (time t11). At time t11, the electronic control unit 20 determines that a torque-down request is present and initiates torque-down control. After time t11, the requested torque is controlled to the torque-down requested torque. Furthermore, upon initiation of torque-down control, regenerative control of the motor 30 begins.

[0068] After the start of the torque down control (immediately after time t11), the torque output from the motor 30 is gradually changed by the gradual change control. Figure 4 The torque is changed drastically as in the ideal MG torque shown by the single-dot chain line, and the desired torque reduction amount is fully regenerated by the motor 30. However, in reality, the responsiveness of the motor 30 and the coordination with the engine 2 need to be considered. Figure 5 The motor torque is gradually changed as shown by the solid line of the actual MG torque. Therefore, the electronic control unit 20 performs a gradual change control of the regenerative torque immediately after the moment t11. In addition, in the gradual change control, the actual MG torque is insufficient with respect to the ideal MG torque, and the actual torque of the motor 30 is insufficient with respect to the torque reduction requirement. In order to reduce the torque by the insufficient amount, the electronic control unit 20 starts an ignition delay control to delay the ignition timing immediately after the moment t11. By controlling the ignition timing with high responsiveness at the initial stage of the torque reduction, the torque reduction of the amount that cannot be completely reduced by the motor 30 can be achieved through the ignition delay control. Therefore, immediately after the moment t11, the ignition timing corresponding to the accelerator opening requirement becomes Figure 4 The ideal ignition timing is shown by the dashed line, but the ignition timing corresponding to the torque reduction request is as follows Figure 4 As shown by the solid line in FIG, the actual ignition timing is controlled to be retarded relative to the ideal ignition timing.

[0069] Then, the actual MG torque matches the ideal MG torque (time t12). At time t12, the electronic control unit 20 ends the gradual change control of the regenerative torque. In this case, regenerative control continues while the actual torque of the motor 30 matches the ideal MG torque (MG required torque). In other words, after time t12, the torque reduction requirement can be met solely by the regenerative amount of the motor 30. Therefore, at time t12, the electronic control unit 20 ends the ignition delay control. During the period from time t11 to time t12, the ignition timing gradually changes to the ignition timing corresponding to the accelerator opening requirement.

[0070] Thereafter, the torque-down request torque matches the accelerator opening request (time t13 ). At time t13 , the electronic control unit 20 ends the torque-down control.

[0071] Thus, in Example 1, regeneration control is executed from time t11 to time t13, and ignition delay control is executed from time t11 to time t12. On the other hand, in Comparative Example 1, regeneration control is not performed, and ignition delay control is executed from time t11 to time t13. According to Example 1, energy can be regenerated by motor 30 through regeneration control, and because the period of execution of ignition delay control is shorter than that of Comparative Example 1, the degradation of fuel economy caused by ignition delay can be suppressed. Consequently, regenerated energy can be increased without additional fuel injection.

[0072] Next, Example 2 will be described. Figure 6 This is a time chart for explaining changes in the vehicle state when the torque-down control in the second embodiment is executed. Figure 7 This is a time chart for explaining changes in the vehicle state when the torque-down control in Comparative Example 2 is executed.

[0073] In Example 2, the torque down control is executed as a vibration reduction control when the accelerator is switched from OFF to ON while deceleration regeneration is in progress during driving. In Comparative Example 2, deceleration regeneration is performed during driving, but the regeneration control for torque down is not executed during the torque down control, and torque down is performed only by ignition retardation control. In Comparative Example 2, as shown in FIG. Figure 7 As shown, if the deceleration regeneration state is switched to the accelerator on (time t21), the deceleration regeneration torque gradually changes toward zero (after time t21) in order to end the regeneration. If it is assumed that the regeneration is stopped suddenly, a shock will be generated. Therefore, in order to suppress the shock, a gradual control of the deceleration regeneration torque is performed. In this way, in Comparative Example 2, although deceleration regeneration is performed when the accelerator is turned off, regeneration for torque reduction is not performed when the torque decreases. In contrast, in Example 2, since regeneration for torque reduction is performed, as shown in FIG. Figure 6 As shown, the desired torque reduction amount can be regenerated by the motor 30 .

[0074] like Figure 6 As shown, before time t21, the accelerator pedal is released while the vehicle 1 is traveling, and deceleration regeneration based on the motor 30 is performed. Thereafter, if the accelerator opening is steeply increased due to the driver's depressing operation on the accelerator pedal, the electronic control unit 20 determines that there is a torque reduction request and starts torque reduction control (time t21). When there is a torque reduction request during deceleration regeneration, the electronic control unit 20 mediates the deceleration regeneration torque and the torque reduction control torque. In other words, the electronic control unit 20 controls the actual torque of the motor 30 so that it becomes the mediated torque. The mediated torque is the torque when the relatively smaller of the deceleration regeneration torque and the torque reduction control torque is selected.

[0075] exist Figure 6 In the example shown, at time t21, the torque-down control torque corresponding to the torque-down request and the deceleration regeneration torque corresponding to the deceleration regeneration request do not match. Immediately after time t21, control is performed so that the mediated torque follows the deceleration regeneration torque. Specifically, immediately after the start of torque-down control, the electronic control unit 20 performs gradual control so that the actual torque of the motor 30 follows the deceleration regeneration torque. Furthermore, the electronic control unit 20 performs ignition retard control to retard the mediated ignition timing.

[0076] The mediated torque then matches the torque-down control torque (time t22). At time t22, the electronic control unit 20 ends the gradual change control of the deceleration regenerative torque. In this case, the gradual change control of the regenerative torque is performed while the actual torque of the motor 30 matches the torque-down control torque.

[0077] Afterwards, the mediated torque is consistent with the ideal MG torque (time t23). At time t23, the electronic control unit 20 ends the gradual change control of the regenerative torque. In this case, the regenerative control is continued in a state where the actual torque of the motor 30 is consistent with the ideal MG torque. That is, after time t23, the torque reduction requirement can be satisfied only by the regeneration amount of the motor 30. Therefore, at time t23, the electronic control unit 20 ends the ignition delay control. During the period from time t21 to time t22, the mediated ignition timing changes in the same way as in Comparative Example 2, and during the period from time t22 to time t23, the mediated ignition timing gradually changes to become the ignition timing corresponding to the accelerator opening requirement. At this time, the mediated ignition timing changes to the advance side in a state where its change amount becomes larger.

[0078] Then, the torque-down request torque matches the accelerator opening request (time t24 ). At time t24 , the electronic control unit 20 ends the torque-down control.

[0079] Thus, in Example 2, regenerative control for torque reduction is executed from time t22 to time t24, and ignition retard control is executed from time t21 to time t23. On the other hand, in Comparative Example 2, regenerative control for torque reduction is not performed, and ignition retard control is executed from time t21 to time t24. According to Example 2, energy regeneration can be performed using motor 30 through regenerative control for torque reduction, and because the period of execution of ignition retard control is shorter than that of Comparative Example 2, degradation of fuel economy caused by ignition retard can be suppressed.

[0080] In addition, Example 3 will be described. Figure 8 This is a time chart for explaining changes in the vehicle state when the torque-down control in the third embodiment is executed. Figure 9 This is a time chart for explaining changes in the vehicle state when the torque-down control in Comparative Example 3 is executed.

[0081] In Example 3, the regeneration control by the motor 30 is executed during the torque reduction control when the vehicle 1 transitions to the idle state. In Comparative Example 3, the regeneration control is not executed when the vehicle 1 transitions to the idle state, and the torque reduction is performed only by the ignition delay control. In this Comparative Example 3, as shown in FIG. Figure 9 As shown, if the accelerator is switched from on to off, the torque reduction control is started (time t31) in order to reduce the engine speed to the idle target speed. In this case, the required torque is controlled to a torque reduction required torque (ISC torque) that is smaller than the accelerator opening requirement (MBT torque). The MBT torque is the torque when the ignition timing becomes MBT. The ISC torque is the torque output to maintain the idle speed. In this way, in Comparative Example 3, in order to reduce the required torque so that the engine speed drops to the idle target speed, although the ignition delay control that delays the ignition timing is performed, the motor-based regeneration is not performed. In contrast, in Example 3, since the regeneration control is performed when transitioning to the idle state, as shown in FIG. Figure 8 As shown, the desired torque reduction amount can be regenerated by the motor 30 .

[0082] like Figure 8 As shown, if the accelerator pedal is released from its depressed state, the electronic control unit 20 determines that a torque-down request has been issued and initiates torque-down control for transitioning to the idle state (time t31). Immediately after time t31, regenerative control of the motor 30 begins, gradually changing the regenerative torque through gradual control. In this gradual control, the electronic control unit 20 executes ignition retardation control to retard the ignition timing in order to reduce the insufficient torque.

[0083] Then, when the actual MG torque matches the ideal MG torque, the MG torque gradual change control and the ignition retard control are terminated (time t32). During the period from time t31 to time t32, the ignition timing is gradually changed to the advanced side compared to Comparative Example 3 to the ignition timing corresponding to the torque-down required torque.

[0084] Thereafter, the engine speed matches the idle target speed (time t33 ). At time t33 , the electronic control unit 20 ends the torque-down control.

[0085] Thus, in Example 3, regeneration control is executed from time t31 to time t33, and ignition retard control is executed from time t31 to time t32. On the other hand, in Comparative Example 3, regeneration control is not performed, and ignition retard control is executed from time t31 to time t33. According to Example 3, energy can be regenerated by the motor 30 through regeneration control for torque reduction, and because the period of execution of ignition retard control is shorter than that of Comparative Example 3, degradation of fuel economy due to ignition retard can be suppressed.

[0086] As described above, according to the embodiment, during torque down, the ignition timing is controlled based on the actual torque of the motor 30, thereby taking into account the response delay of the motor 30. This can suppress the occurrence of shock during torque down and improve fuel economy.

[0087] Furthermore, during torque reduction, the amount of energy regenerated in motor 30 can be increased without additional fuel injection in engine 2. This allows for both improved drivability and improved fuel economy. Furthermore, even with highly responsive torque reduction control, torque reduction as required can be achieved.

[0088] As a variation of the above-described embodiment, the gradual change guard value is not limited to a value that changes according to vehicle speed. For example, the gradual change guard value changes according to the engagement state of the lockup clutch LC and is set so that the regenerative torque change per unit time is greatest when the lockup clutch LC is not in the directly engaged state. When the lockup clutch LC is not in the directly engaged state (released or partially engaged), torque is transmitted in the torque converter 11 via the hydraulic oil.

[0089] Furthermore, the motor 30 can be positioned anywhere it is connected to the crankshaft 2a of the engine 2 in a power-transmittable manner, and its location is not particularly limited. In short, as long as the motor 30 can function as an AC generator, its location and connection point with the engine 2 are not particularly limited. Furthermore, the structure of the automatic transmission 12 is not limited to that described above.

Claims

1. A control device for a vehicle comprising an internal combustion engine, a rotating electrical machine connected to the internal combustion engine in a power-transmittable manner, and a torque converter disposed between the internal combustion engine and an automatic transmission, wherein, when a torque-down request corresponding to a vehicle state is issued, the control device is capable of performing torque down by ignition retardation control for retarding the ignition timing of the internal combustion engine and regeneration control based on regeneration of the rotating electrical machine. The vehicle control device is characterized in that: The torque converter includes a lockup clutch provided in a power transmission path between the rotating electric machine and the drive wheels. When the actual torque of the rotating electric machine based on the regenerative control is insufficient for the torque reduction request, the torque reduction is performed by retarding the ignition timing of the internal combustion engine to compensate for the insufficient torque. a guard value for gradually changing the regenerative torque output from the rotating electrical machine by the regenerative control; The protection value is a value that changes according to the vehicle speed and is set in such a way that the higher the vehicle speed, the greater the change in regenerative torque per unit time. The protection value is also a value that changes according to the operating state of the lockup clutch and is set in such a way that the change in regenerative torque per unit time is large when the lockup clutch is not in a directly connected state.

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