JP5741015B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control apparatus including an engine and an electric motor as power sources.

  As a vehicle control device, a technique described in Patent Document 1 is disclosed. In this publication, a coast torque corresponding to a driver's deceleration request is generated by an engine and a motor generator during coasting.

JP 2007-168565 A

  For example, when the vehicle decelerates and becomes less than a certain vehicle speed, it is necessary to output a positive torque as a creep torque instead of a negative torque as a coast torque, so that these torques can be switched smoothly. There is a demand for setting the coast torque to zero and switching the torque after that. However, even if the target coast torque is set to zero while the engine and the motor generator are torque controlled, it is difficult to achieve zero torque because of variations in engine torque. Further, even when a clutch is provided between the motor generator and the drive wheel and the clutch is slip-controlled, it is still difficult to realize zero torque due to clutch variations. This is a common problem not only in the case of transition from the coast state to the drive state, but also in the case where the target torque is equivalent to zero.

  The present invention has been made paying attention to the above problem, and an object of the present invention is to provide a vehicle control device that can achieve a stable traveling state when the target torque is set to zero.

To achieve the above object, in vehicles of the control device of the present application is a power source for generating a torque corresponding to the target coasting torque by torque control of the engine and the motor generator, between the power source and the driving wheels A request to make the target coast torque equivalent to zero is output when the clutch that is engaged and engaged by operating the clutch piston by hydraulic pressure and when the torque generated by the power source is reversed from negative torque to positive torque. When the clutch is released and controlled so that the clutch piston does not excessively stroke, the motor generator is controlled by the torque control so that the input side rotational speed of the clutch and the output rotational speed of the clutch are the same. The control is performed so that slip does not occur in the clutch. And means, with a.

  Therefore, since the motor generator generates torque so as to achieve the rotational speed corresponding to the driving wheel rotational speed, even if the engine torque or the transmission torque capacity of the clutch varies, a zero-torque equivalent state can be realized and a stable traveling state can be achieved. Can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall system diagram illustrating a rear-wheel drive hybrid vehicle according to a first embodiment. FIG. 3 is a control block diagram illustrating an arithmetic processing program in the integrated controller according to the first embodiment. It is a figure which shows an example of the target driving force map used for target driving force calculation in the target driving force calculating part of FIG. It is a figure showing the relationship between a mode map and an estimated gradient in the mode selection part of FIG. It is a figure which shows the normal mode map used for selection of the target mode in the mode selection part of FIG. 3 is a normal speed shift map of the first embodiment. 3 is a shift map for an M range according to the first embodiment. 3 is a target coast torque map when the D range is selected in the first embodiment. 3 is a target coast torque map when an M range is selected in the first embodiment. It is a figure showing each gear stage coefficient for M ranges of Example 1. FIG. 3 is a flowchart illustrating a coast regenerative braking force control process according to the first embodiment. 3 is a flowchart showing a zero torque control process during coasting according to the first embodiment. 3 is a time chart illustrating a control process including zero torque control during coasting according to the first embodiment.

  First, the drive system configuration of the hybrid vehicle will be described. FIG. 1 is an overall system diagram showing a hybrid vehicle by rear wheel drive to which the engine start control device of the first embodiment is applied. As shown in FIG. 1, the drive system of the hybrid vehicle in the first embodiment includes an engine E, a first clutch CL1, a motor generator MG, a second clutch CL2, an automatic transmission AT, a propeller shaft PS, It has a differential DF, a left drive shaft DSL, a right drive shaft DSR, a left rear wheel RL (drive wheel), and a right rear wheel RR (drive wheel). FL is the front left wheel and FR is the front right wheel.

  The engine E is, for example, a gasoline engine, and the valve opening degree of the throttle valve and the like are controlled based on a control command from the engine controller 1 described later. The engine output shaft is provided with a flywheel FW.

  The first clutch CL1 is a clutch interposed between the engine E and the motor generator MG, and the control created by the first clutch hydraulic unit 6 based on a control command from the first clutch controller 5 described later. Fastening / release including slip fastening is controlled by hydraulic pressure.

  The motor generator MG is a synchronous motor generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator, and the three-phase AC generated by the inverter 3 is generated based on a control command from a motor controller 2 described later. It is controlled by applying. The motor generator MG can operate as an electric motor that is driven to rotate by receiving power supplied from the battery 4 (hereinafter, this state is referred to as “power running”), or when the rotor is rotated by an external force. Can function as a generator that generates electromotive force at both ends of the stator coil to charge the battery 4 (hereinafter, this operation state is referred to as “regeneration”). Note that the rotor of the motor generator MG is connected to the input shaft of the automatic transmission AT via a damper (not shown).

  The second clutch CL2 is a clutch interposed between the motor generator MG and the left and right rear wheels RL and RR, and is generated by the second clutch hydraulic unit 8 based on a control command from the AT controller 7 described later. The fastening / release including slip fastening is controlled by the control hydraulic pressure.

  The automatic transmission AT is a transmission that automatically switches the stepped gear ratio such as 5 forward speeds, 1 reverse speed, etc. according to the vehicle speed, accelerator opening, etc., and the second clutch CL2 is newly added as a dedicated clutch However, some frictional engagement elements are used among a plurality of frictional engagement elements that are engaged at each gear stage of the automatic transmission AT. This automatic transmission AT can select the D range, neutral range, R range, etc. by operating the shift lever operated by the driver, and in addition to the D range, achieves only the gear stage selected by the driver. M range (manual range) to be selected is configured to be selectable. When the D range is selected, the optimum gear is selected according to the vehicle speed and the accelerator pedal opening, and the gear is automatically shifted. When the M range is selected, the speed is changed so that the gear position is in accordance with the driver's shift lever operation.

  When achieving the first forward speed, the automatic transmission AT achieves a one-way clutch as one of the engagement elements when the D range is selected, and friction engagement in place of the one-way clutch when the M mode is selected. The element is achieved as one of the engaging elements. That is, when the D range is selected, when torque is transmitted from the engine E and / or motor generator MG to the drive wheels (that is, in the drive state), the one-way clutch is engaged and the first forward speed is increased. When the torque is transmitted from the drive wheel to the engine E and / or the motor generator MG (that is, in the coast state), the one-way clutch is released, so that the coast torque does not act. On the other hand, when the M range is selected, the frictional engagement element is not released in either the drive state or the coast state, and therefore, the coast torque is always applied. The output shaft of the automatic transmission AT is connected to the left and right rear wheels RL and RR via a propeller shaft PS, a differential gear DF, a left drive shaft DSL, and a right drive shaft DSR as vehicle drive shafts. The first clutch CL1 and the second clutch CL2 are, for example, wet multi-plate clutches that can continuously control the oil flow rate and hydraulic pressure with a proportional solenoid.

  The brake unit 900 includes a hydraulic pressure pump and a plurality of electromagnetic valves, so-called brakes that secure the hydraulic pressure corresponding to the required braking torque by increasing the pump pressure, and control the wheel cylinder pressure by controlling the opening and closing of the electromagnetic valves of each wheel. By-wire control is possible. Each wheel FR, FL, RR, RL is provided with a brake rotor 901 and a caliper 902, and generates a friction braking torque by the brake fluid pressure supplied from the brake unit 900. In addition, the type provided with the accumulator etc. may be sufficient as a hydraulic pressure source, and the structure provided with the electric caliper instead of the hydraulic brake may be sufficient.

  This hybrid drive system has three travel modes according to the engaged / released state of the first clutch CL1. The first travel mode is an electric vehicle travel mode (hereinafter abbreviated as “EV travel mode”) as a motor use travel mode that travels using only the power of the motor generator MG as a power source with the first clutch CL1 opened. It is. The second travel mode is an engine use travel mode (hereinafter abbreviated as “HEV travel mode”) in which the first clutch CL1 is engaged and the engine E is included in the power source. The third travel mode is an abbreviated engine use slip travel mode (hereinafter referred to as “WSC travel mode”) in which the second clutch CL2 is slip-controlled while the first clutch CL1 is engaged and the engine E is included in the power source. ). This mode is a mode in which creep running can be achieved particularly when the battery SOC is low or the engine water temperature is low. When transitioning from the EV travel mode to the HEV travel mode, the first clutch CL1 is engaged and the engine is started using the torque of the motor generator MG.

  The “HEV travel mode” has three travel modes of “engine travel mode”, “motor assist travel mode”, and “travel power generation mode”.

  In the “engine running mode”, the drive wheels are moved using only the engine E as a power source. In the “motor assist travel mode”, the drive wheels are moved by using the engine E and the motor generator MG as power sources. The “running power generation mode” causes the motor generator MG to function as a generator at the same time as the drive wheels RR and RL are moved using the engine E as a power source.

  During constant speed operation or acceleration operation, motor generator MG is operated as a generator using the power of engine E. Further, during deceleration operation, the braking energy is regenerated and generated by the motor generator MG and used for charging the battery 4. Further, as a further mode, there is a power generation mode in which the motor generator MG is operated as a generator using the power of the engine E when the vehicle is stopped.

  Next, the control system of the hybrid vehicle will be described. As shown in FIG. 1, the hybrid vehicle control system according to the first embodiment includes an engine controller 1, a motor controller 2, an inverter 3, a battery 4, a first clutch controller 5, and a first clutch hydraulic unit 6. The AT controller 7, the second clutch hydraulic unit 8, the brake controller 9, and the integrated controller 10 are configured. The engine controller 1, the motor controller 2, the first clutch controller 5, the AT controller 7, the brake controller 9, and the integrated controller 10 are connected via a CAN communication line 11 that can exchange information with each other. Has been.

  The engine controller 1 inputs the engine speed information from the engine speed sensor 12, and controls the engine operating point (Ne: engine speed, Te: engine torque) according to the target engine torque command from the integrated controller 10, etc. For example, to a throttle valve actuator (not shown). More detailed engine control contents will be described later. Information such as the engine speed Ne is supplied to the integrated controller 10 via the CAN communication line 11.

  The motor controller 2 inputs information from the resolver 13 that detects the rotor rotational position of the motor generator MG, and according to a target motor generator torque command from the integrated controller 10 or the like, the motor operating point (Nm: motor generator) of the motor generator MG. A command for controlling the rotation speed (Tm: motor generator torque) is output to the inverter 3. The motor controller 2 monitors the battery SOC indicating the state of charge of the battery 4. The battery SOC information is used as control information for the motor generator MG and is supplied to the integrated controller 10 via the CAN communication line 11. Is done.

  The first clutch controller 5 inputs sensor information from the first clutch hydraulic pressure sensor 14 and the first clutch stroke sensor 15, and according to the first clutch control command from the integrated controller 10, the first clutch CL1 is engaged / released. A command to control is output to the first clutch hydraulic unit 6. Information on the first clutch stroke C1S is supplied to the integrated controller 10 via the CAN communication line 11.

  The AT controller 7 inputs sensor information from the accelerator opening sensor 16, the vehicle speed sensor 17, the second clutch hydraulic pressure sensor 18, and an inhibitor switch that outputs a signal corresponding to the position of the shift lever operated by the driver. 10 is output to the second clutch hydraulic unit 8 in the AT hydraulic control valve in response to the second clutch control command from 10. Information on the accelerator pedal opening APO, the vehicle speed VSP, and the inhibitor switch is supplied to the integrated controller 10 via the CAN communication line 11.

  Further, in the AT controller 7, when the D range is selected, when the normal range shift map having a normal shift line for determining the gear position according to the accelerator opening and the vehicle speed and the M range are selected. And an M-range shift map having an M-range shift line forcibly shifting from the viewpoint of protecting the engine and the like. FIG. 6 is a normal speed change map according to the first embodiment. In FIG. 6, a line indicated by a solid line is an upshift shift line, and is set between the respective shift stages. In FIG. 6, a line indicated by a dotted line is a normal downshift line, and is set between the respective shift stages. In addition, a cold shift line indicated by a one-dot chain line is set for the downshift shift line for normal use. The cold shift line is obtained by offsetting the shift line to the high vehicle speed side according to the deceleration.

  That is, even if a shift command is output, the actual shift operation requires a certain amount of time. In particular, at the time of coast deceleration, if the speed change operation is delayed, the engine speed is excessively reduced, which is likely to cause engine stall or the like. Therefore, when the deceleration in the coasting state is large, an excessive decrease in the engine speed is suppressed by outputting a downshift command on the higher vehicle speed side than when the deceleration is small. When engine stop is permitted, it is not necessary to avoid a decrease in engine speed. In this case, a downshift command is output according to a normal downshift shift line.

  FIG. 7 is an M-range shift map according to the first embodiment. In FIG. 7, a line indicated by a solid line is a forced upshift line for forcibly upshifting, and a line indicated by a dotted line in FIG. 7 is a forcible downshift line for forcibly downshifting. Basically, in the M range, priority is given to the gear selected by the driver, but the gear is forcibly shifted from the viewpoint of preventing engine overspeed and avoiding engine stall due to low rotation and low torque. is there.

  The brake controller 9 inputs sensor information from the wheel speed sensor 19 that detects the wheel speeds of the four wheels and the brake stroke sensor 20, and satisfies the driver-requested braking torque required from the brake stroke BS, for example, when the brake is depressed. The cooperative regenerative control is performed so that the braking force to be achieved is achieved by the regenerative braking force and the frictional braking force. Needless to say, the brake fluid pressure can be arbitrarily generated not only by the brake fluid pressure corresponding to the driver requested braking torque but also by other control requirements.

  The integrated controller 10 manages the energy consumption of the entire vehicle and has a function for running the vehicle with the highest efficiency. The integrated controller 10 detects the motor rotational speed Nm, and the second clutch output rotational speed N2out. A second clutch output speed sensor 22 for detecting the second clutch, a second clutch torque sensor 23 for detecting the second clutch transmission torque capacity TCL2, a brake hydraulic pressure sensor 24, and a temperature sensor 10a for detecting the temperature of the second clutch CL2. The information from the G sensor 10b for detecting the longitudinal acceleration and the information obtained through the CAN communication line 11 are input.

  The integrated controller 10 also controls the operation of the engine E according to the control command to the engine controller 1, the operation control of the motor generator MG based on the control command to the motor controller 2, and the first control command to the first clutch controller 5. Engagement / release control of the clutch CL1 and engagement / release control of the second clutch CL2 by a control command to the AT controller 7 are performed.

  Below, the control calculated by the integrated controller 10 of Example 1 is demonstrated using the block diagram shown in FIG. For example, this calculation is performed by the integrated controller 10 every control cycle of 10 msec. The integrated controller 10 includes a target driving force calculation unit 100, a mode selection unit 200, a target charge / discharge calculation unit 300, an operating point command unit 400, and a shift control unit 500.

  The target driving force calculation unit 100 calculates a target driving force tFoO (driver required torque) from the accelerator pedal opening APO and the vehicle speed VSP using the target driving force map shown in FIG. Further, in the target driving force calculation unit 100, when the accelerator pedal opening APO is zero (that is, the driver does not intend to accelerate), the engine braking force is applied regardless of the brake pedal operation (the driver's braking request). A coast regenerative control unit 101 that calculates a corresponding target coast torque and applies a braking force including a regenerative braking force to the drive wheels is provided.

  Here, the coast regeneration control unit 101 calculates, as the target coast torque, the braking torque transmitted to the drive wheels corresponding to the engine friction generated in a normal engine vehicle, and when the first clutch CL1 is engaged. When the actual engine friction is set and the first clutch CL1 is disengaged, the motor generator MG simulates the engine friction.

  FIG. 8 is a target coast torque map when the D range is selected in the first embodiment. In a situation where the stop of the engine operation is permitted, it is not necessary to avoid a decrease in the engine speed. In this case, a downshift command is output along the normal downshift line. Therefore, a predetermined target coast torque is set at least at the second speed, and the target coast is gradually increased from the vehicle speed at which the coast torque decrease starts higher than the normal shift 21 down vehicle speed at which the 2-1 downshift line of the normal downshift line is set. The torque is set so that the coast torque becomes zero when the torque is reduced and the vehicle speed reaches the normal downshift 21 down vehicle speed. After that, even if the first speed is changed, the target coast torque is set to a positive value, that is, the creep torque is set.

  Further, in a situation where the stop of engine operation is not permitted, it is necessary to avoid a decrease in engine speed. In this case, a downshift command is output along the cold shift line. Therefore, a predetermined target coast torque is set at least at the second speed, and the target coast torque is gradually decreased from the start speed of the coast torque decrease higher than the cold shift 21 down vehicle speed in which the 2-1 downshift line of the cold shift line is set. The coast torque is set to 0 when the vehicle speed is reduced and the vehicle speed reaches the cold speed 21 down vehicle speed. In other words, the coast torque is set to be zero before reaching the cold shift 21 down vehicle speed that is higher than the normal shift 21 down vehicle speed by a predetermined vehicle speed. Thereafter, since the target coast torque is output as a positive value (creep torque is output), the one-way clutch can be engaged, and an excessive decrease in the engine speed can be suppressed.

  FIG. 9 is a target coast torque map when the M range is selected in the first embodiment. In this case, the target coast torque set in accordance with each gear position is set as shown in FIG. 9 regardless of permission to stop the engine operation or the like. The target coast torque is set so that the target coast torque becomes zero at a predetermined vehicle speed higher than the forced 21 down shift vehicle speed set in the M range shift map. Thus, the reason why the target coast torque is set to 0 over a relatively wide range is that the timing at which the forced 21-down vehicle speed passes varies due to deceleration. When the target coast torque is set to 0, coasting zero torque control is performed to switch the control state of the motor generator MG from the previous torque control to the rotational speed control. Details of this control will be described later.

  The target coast torque is set so as to decrease the coast torque at a predetermined gradient from the coast torque decrease start vehicle speed. After the 2-1 down shift is forcibly performed, the creep torque is set to be output. At the other shift speeds, a target coast torque is set based on the target coast torque of the fifth speed. FIG. 10 is a diagram illustrating gear ratio coefficients for the M range according to the first embodiment. The target coast torque set at the fifth speed is normalized to 1 as the base torque, and a value obtained by multiplying the target coast torque at the fifth speed by a coefficient corresponding to the gear ratio is set as the target coast torque.

  When the target coast torque is smaller than the actual engine friction generated at the present time, it is only necessary to output the drive torque instead of the regenerative torque to the motor generator MG, thereby achieving the target coast torque. Thereby, the target coast torque can be realized with high accuracy.

  The mode selection unit 200 has a mode map. FIG. 4 is a mode map of the first embodiment. The mode map has an EV travel mode, a WSC travel mode, and an HEV travel mode, and the target mode is calculated from the accelerator pedal opening APO and the vehicle speed VSP. However, even if the EV travel mode is selected, if the battery SOC is equal to or lower than the predetermined value, the “HEV travel mode” or the “WSC travel mode” is forcibly set as the target mode.

  In the mode map of FIG. 4, the HEV → WSC switching line is a lower limit at which the rotational speed is smaller than the idle rotational speed of the engine E when the automatic transmission AT is in the first speed in the region below the predetermined accelerator opening APO1. It is set in a region lower than the vehicle speed VSP1. Further, since a large driving force is required in a region where the accelerator opening APO1 is equal to or greater than the predetermined accelerator opening APO1, the WSC travel mode is set up to a vehicle speed VSP1 ′ region that is higher than the lower limit vehicle speed VSP1. When the battery SOC is low and the EV travel mode cannot be achieved, the WSC travel mode is selected even when starting.

  When the accelerator pedal opening APO is large, it may be difficult to achieve the request with the engine torque and the motor generator torque corresponding to the engine speed near the idle speed. Here, more engine torque can be output if the engine speed increases. From this, if the engine speed is increased and a larger torque is output, even if the WSC drive mode is executed up to a vehicle speed higher than the lower limit vehicle speed VSP1, the WSC drive mode is changed to the HEV drive mode in a short time. be able to. This case corresponds to the WSC region extended to the lower limit vehicle speed VSP1 ′ shown in FIG.

  The target charge / discharge calculation unit 300 calculates the target charge / discharge power tP from the battery SOC using the target charge / discharge amount map shown in FIG. In the target charge / discharge amount map, the EVON line (MWSCON line) for enabling or disabling the EV driving mode is set to SOC = 50%, and the EVOFF line (MWSCOFF line) is set to SOC = 35%. Yes.

  When SOC ≧ 50%, the EV driving mode area appears in the mode map of FIG. Once the EV area appears in the mode map, it continues to appear until the SOC drops below 35%. Note that the EV travel mode area may be set to be wide when the battery SOC is high, and may be set to be narrow when the battery SOC is low. In this case, when the battery SOC is low, it is preferable to set the EV travel mode region to be narrowed as the vehicle speed increases so as not to place an excessive burden on the battery.

  When SOC <35%, the EV drive mode area disappears in the mode map of FIG. When the EV drive mode area disappears from within the mode map, this area continues to disappear until the SOC reaches 50%.

  The operating point command unit 400 uses the accelerator pedal opening APO, the target driving force tFoO (driver required torque), the target mode, the vehicle speed VSP, and the target charging / discharging power tP as transient targets for these operating points. The target engine torque, the target motor generator torque, the target second clutch transmission torque capacity TCL2 *, the target gear position of the automatic transmission AT, and the first clutch solenoid current command are calculated. Further, the operating point command unit 400 is provided with an engine start control unit that starts the engine E when the EV travel mode is changed to the HEV travel mode.

  Shift control unit 500 drives and controls a solenoid valve in automatic transmission AT so as to achieve the target second clutch transmission torque capacity TCL2 * and the target shift speed according to the shift schedule shown in the shift map. In the shift map, a target gear position is set in advance based on the vehicle speed VSP and the accelerator pedal opening APO.

(Coast regenerative braking force control process)
Next, the coast regenerative braking force control process of the first embodiment will be described. FIG. 11 is a flowchart illustrating a coast regenerative braking force control process according to the first embodiment. This process is performed in the coast regeneration control unit 101.
In step S1, it is determined whether or not the M range is selected. If the M range is selected, the process proceeds to step S2. If the D range is selected, the process proceeds to step S4.
In step S2, the M range shift map in which the M range shift line is set is selected.
In step S3, a target coast torque for the M range is selected.

  In step S4, it is determined whether or not an engine stop prohibition condition is satisfied. When the condition is satisfied, that is, when the engine stop is prohibited, the process proceeds to step S5, and the condition is not satisfied, that is, the engine stop is not prohibited (permitted). If yes, go to step S7. It should be noted that the engine stop prohibition condition may be that the engine is stopped when the EV travel mode is set in the normal mode map. On the other hand, when the battery SOC is low, or when the engine water temperature is low and it is difficult to perform a proper start when the engine is restarted, the EV running mode is not permitted and the engine is prohibited from being stopped, that is, HEV running. This means that the mode or WSC driving mode is selected.

In step S5, a shift line based on the cold shift line is selected from the normal shift map.
In step S6, a cold target coast torque is selected.
In step S7, a shift line based on the normal shift line is selected from the normal shift map.
In step S8, the target coast torque for normal is selected.

(Zero torque control during coasting)
Next, the control state switching process of motor generator MG in a state where the target coast torque for M range is selected in step S3 will be described. FIG. 12 is a flowchart showing the zero torque control process during coasting according to the first embodiment.
In step S31, it is determined whether or not the M range is selected. If the M range is selected, the process proceeds to step S32. Otherwise, the control flow ends.
In step S32, it is determined whether or not the target coast torque is 0. When the target coast torque is 0, the process proceeds to step S33. Otherwise, the control flow ends.
In step S33, the motor generator MG is set to rotation speed control, and the target rotation speed is set to a value obtained by multiplying the output rotation speed of the second clutch CL2 by the gear ratio of the automatic transmission (first gear ratio).

Next, the operation based on the control flow will be described. FIG. 13 is a time chart showing control processing including zero torque control during coasting according to the first embodiment. The following operation is a traveling state in which the vehicle is decelerating due to the coast state. When the M range is selected, a downshift to the first speed is performed, and a creep torque is output below a predetermined vehicle speed.
When the M range is selected, the target coast torque corresponding to the gear selected by the driver is selected (see FIG. 9). At this time, the first speed when the M range is selected does not have the effect of the one-way clutch and may cause a large deceleration. Therefore, when setting the target coast torque, the coast torque is set to gradually decrease from the coast torque reduction start vehicle speed higher than the 21-down vehicle speed for the M range toward the predetermined vehicle speed. As a result, the deceleration shock does not change abruptly even if a downshift to the first speed is forcibly performed from any gear stage, and the shift shock is suppressed. When the target coast torque is a negative value, both engine E and motor generator MG are torque controlled. When there is a power generation request, the engine E outputs a positive torque corresponding to the power generation request, and the motor generator MG generates a negative torque obtained by adding both the positive torque output from the engine E and the target coast torque. Generate coasting torque.

  When the target coast torque is set to 0 at time t1, the control state of motor generator MG is switched from torque control to rotation speed control, and the second clutch output side rotation corresponding to the drive wheel rotation speed at that time The number (that is, the automatic transmission input rotational speed) is calculated, and this value is set as the target rotational speed. As a result, motor generator MG performs control so that slip does not occur in second clutch CL2, and thus achieves zero torque, which is the target coast torque.

  When the second clutch CL2 is completely engaged, there is a concern about variations in engine torque. However, variations in the engine torque are absorbed by the motor generator MG, so that torque fluctuations are not transmitted to the drive wheels. Further, the second clutch CL2 is slip-controlled when transiting to the WSC travel mode. At this time, since the transmission torque capacity of the second clutch CL2 is controlled according to the required torque, when the target coast torque is 0, control is performed within a range in which the clutch piston is completely released and the clutch piston does not excessively stroke. Is done. This is to ensure controllability when the transmission torque capacity is next applied to the second clutch CL2. However, since clutch stroke control also varies, it is difficult to achieve zero torque by clutch control. On the other hand, the second clutch CL2 is controlled to have the same rotational speed as the output-side rotational speed of the second clutch CL2 by controlling the rotational speed of the motor generator MG that matches the rotational speed of the input side of the second clutch CL2. Even if the slip state does not occur in CL2 and the transmission torque capacity varies, torque fluctuation is not transmitted to the drive wheels.

  At time t2, when the target coast torque changes from 0 to a positive torque that is a creep torque, motor generator MG maintains the engine speed control and is set to the engine idle engine speed equivalent value as the target engine speed. At this time, the second clutch CL2 is controlled to output a target coast torque (in this case, creep torque), and a creep torque corresponding to the transmission torque capacity of the second clutch CL2 is output to the drive wheels.

  As described above, in the hybrid vehicle of the first embodiment, the following effects can be obtained.

(1) When a target coast torque (target torque) is generated by a power source composed of the engine E and the motor generator MG and torque control of the power source, a request to make the target coast torque equivalent to zero is output The motor generator MG is switched from torque control to rotational speed control, and the target rotational speed in the rotational speed control is obtained by multiplying the output rotational speed of the second clutch CL2 by the gear ratio of the automatic transmission (corresponding to the driving wheel rotational speed). Coast regeneration control unit 101 (control means).
Therefore, since motor generator MG generates torque so as to achieve a rotational speed corresponding to the drive wheel rotational speed, a zero-torque equivalent state can be realized even if the engine torque varies, and a stable traveling state can be achieved.

  (2) The coast regeneration control unit 101 sets the control state of the engine E to torque control with the required power generation torque as the target torque when the motor generator MG is switched to the rotational speed control. Thus, motor generator MG can automatically generate power by controlling the rotational speed.

(3) A power source having a motor generator MG, a second clutch CL2 interposed between the power source and the driving wheel, and a target coast by controlling the torque of the power source while slip-controlling the second clutch CL2 clutch. When a request to set the target coast torque to zero is output when generating torque, the motor generator MG is switched from torque control to rotation speed control, and the target rotation speed in the rotation speed control is set to the second clutch. And a control means for setting the value obtained by multiplying the output speed of the CL2 by the gear ratio of the automatic transmission (a value corresponding to the drive wheel speed).
Therefore, since the motor generator MG generates torque so as to achieve the rotational speed corresponding to the driving wheel rotational speed, even if the transmission torque capacity of the second clutch CL2 varies, a zero-torque equivalent state can be realized and a stable running state Can be achieved.

  (4) A manual range for shifting to the selected gear stage by the driver's shift lever operation is provided, and the coast regeneration control unit 101 selects the first speed in the manual range and sets the target coast torque to zero. When the request is output, the motor generator MG is switched to the rotational speed control. In this way, by controlling the rotational speed of the motor generator MG only in a specific traveling scene, it is possible to reduce the situation where torque is not exchanged with the drive wheels, and improve the performance as a vehicle. be able to.

  Although the present invention has been described based on the first embodiment, the specific configuration may be other configurations. For example, in the first embodiment, the present invention is applied to a hybrid vehicle. However, an electric vehicle can be similarly applied as long as the vehicle includes a motor as a drive source.

  In the first embodiment, the FR type hybrid vehicle has been described. However, an FF type hybrid vehicle may be used.

E engine
CL1 1st clutch
MG motor generator
CL2 2nd clutch
AT automatic transmission 1 engine controller 2 motor controller 3 inverter 4 battery 5 first clutch controller 6 first clutch hydraulic unit 7 AT controller 8 second clutch hydraulic unit 9 brake controller 10 integrated controller 24 brake hydraulic sensor
100 Target driving force calculator
200 Mode selection section
300 Target charge / discharge calculator
400 Operating point command section
500 Shift control

Claims (2)

A power source that generates torque according to the target coast torque by controlling the torque of the engine and the motor generator;
A clutch that is interposed between the power source and the drive wheel and that is operated by hydraulically operating a clutch piston;
When reversing the torque generated by the power source from a negative torque to a positive torque, if a request to make the target coast torque equivalent to zero is output, the clutch piston is moved within the range where the clutch piston does not excessively stroke. and release control, the motor-generator, from the torque control is switched to the speed control input side speed of the clutch and the output side speed of the clutch is controlled to be the same rotation speed, the clutch Control means for controlling so that slip does not occur ;
A vehicle control device comprising: The vehicle control device according to claim 1,
It has a manual range that shifts to the selected gear position by the driver's shift lever operation,
The control device is executed when the first speed is selected in the manual range .

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