JP5673145B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device that performs slip control on a fastening element between a power source and drive wheels.

  As a vehicle control device, a technique described in Patent Document 1 is disclosed. This gazette discloses a technique for performing an engine use slip mode in which the driving force of both the engine and the motor is used to start while slipping the clutch between the motor and the drive wheels.

JP 2006-315488 A

  However, when starting while slipping the clutch, it is necessary to consider the judder of the clutch. Here, if the rising gradient of the clutch transmission torque capacity is reduced in order to reduce step vibration to the driving force transmission system, the time until acceleration is generated in the vehicle becomes long, and drivability cannot be ensured. On the other hand, in order to ensure drivability, when the rising gradient of the transmission torque capacity of the clutch is increased, there is a problem that step vibration to the driving force transmission system increases and judder occurs.

  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 capable of ensuring drivability at the time of starting and suppressing judder.

  In order to achieve the above object, the vehicle control apparatus of the present invention increases the clutch transmission torque capacity according to the driver's intention during the control of slipping the clutch interposed between the power source and the drive wheels. When the transmission torque capacity of the clutch exceeds the judder generation determination threshold value for determining whether or not the vehicle is in the judder generation region, and the transmission torque capacity is in the judder generation region, the clutch transmission torque The increase speed of the capacity is set to be smaller than the increase speed of the transfer torque capacity when the transmission torque capacity of the clutch is less than the judder generation determination threshold.

  Therefore, driving performance is ensured by increasing the transmission torque capacity according to the driver's intention up to the judder generation determination threshold that represents the judder generation region, and by suppressing the increase in transmission torque capacity above the judder generation determination threshold, Generation of judder can be suppressed.

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. It is a figure which shows the MWSC corresponding | compatible mode map used for selection of the target mode in the mode selection part of FIG. It is a figure which shows an example of the target charging / discharging amount map used for the calculation of target charging / discharging electric power in the target charging / discharging calculating part of FIG. It is the schematic showing the engine operating point setting process in WSC driving mode. It is a map showing the engine target speed in WSC driving mode. It is a time chart showing the change of the engine speed when raising a vehicle speed in a predetermined state. FIG. 3 is a block diagram illustrating a configuration of a judder generation determination threshold value calculation unit according to the first embodiment. It is a block diagram showing the structure of the clutch change rate limitation value calculating part of Example 1. 6 is a time chart showing a starting clutch torque increase control process according to the first embodiment. 1 is a schematic perspective view illustrating a configuration of a suspension member attached to a vehicle driving force transmission system according to a 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. Details will be described later.

  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.

  The brake controller 9 inputs sensor information from the wheel speed sensor 19 and the brake stroke sensor 20 that detect the respective wheel speeds of the four wheels. For example, when braking the brake, the driver requested braking torque obtained from the brake stroke BS is applied. When the regenerative braking torque is insufficient, the regenerative cooperative brake control is performed based on the regenerative cooperative control command from the integrated controller 10 so that the shortage is supplemented by the mechanical braking torque (braking torque by the friction brake). 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.

  Further, the integrated controller 10 includes a gradient load torque equivalent value calculation unit 600 that calculates an equivalent value of a gradient load torque acting on the wheel based on an estimated road gradient described later, and a driver brake when a predetermined condition is satisfied. A second clutch protection control unit 700 that generates brake fluid pressure regardless of the pedal operation amount is provided. The towing amount that represents the weight of the towed vehicle when traveling with a towed vehicle (when towing a faulty vehicle or towing a boat or camper) attached to the rear of the vehicle A towing amount calculation unit 101, a clutch plate temperature calculation unit 102 for estimating the clutch plate temperature of the second clutch CL2, and a clutch plate deterioration degree calculation unit 103 for estimating the clutch plate deterioration degree of the second clutch CL2. Have. The towing amount calculation unit 101 estimates from the relationship between output torque and vehicle acceleration when traveling on a flat road. The clutch plate temperature is estimated from the relationship between the slip amount of the second clutch CL2 and the transmission torque capacity. A temperature sensor or the like may be provided directly or may be estimated from other temperature sensor detection values. The degree of deterioration of the clutch plate is obtained by cumulatively integrating the amount of heat generated in the clutch plate from the product of the slip amount of the second clutch CL2 and the transmission torque capacity, and estimating the degree of deterioration according to this integrated value. Note that it may be estimated from a travel distance or the like, or may be estimated from a difference between the actual transmission torque capacity and the command transmission torque capacity of the second clutch CL2.

  The value corresponding to the gradient load torque is a value corresponding to the load torque acting on the wheels when the gravity acting on the vehicle due to the road surface gradient tries to move the vehicle backward. A brake that generates mechanical braking torque on a wheel generates braking torque by pressing a brake pad against a brake rotor 901 by a caliper 902. Therefore, when the vehicle is about to move backward due to gravity, the direction of the braking torque is the vehicle forward direction. The braking torque that coincides with the vehicle forward direction is defined as the gradient load torque. Since this gradient load torque can be determined by the road surface gradient and the inertia of the vehicle, a gradient load torque equivalent value is calculated based on the vehicle weight or the like preset in the integrated controller 10. Note that the gradient load torque may be set as an equivalent value as it is, or may be set as an equivalent value by adding or subtracting a predetermined value or the like.

  The second clutch protection control unit 700 calculates a braking torque minimum value (braking torque equal to or greater than the above-described gradient load torque) that can avoid a so-called rollback in which the vehicle moves backward when the vehicle stops on a gradient road. When the condition (the road surface gradient is equal to or greater than a predetermined value and the vehicle is stopped) is satisfied, the braking torque minimum value is output to the brake controller 9 as the control lower limit value.

  In the first embodiment, the brake fluid pressure is applied only to the rear wheels that are drive wheels. However, the brake fluid pressure may be supplied to the four wheels in consideration of the front and rear wheel distribution, or the brake fluid pressure may be supplied only to the front wheels.

  On the other hand, when the predetermined condition is not satisfied, a command for gradually decreasing the braking torque is output. Further, the second clutch protection control unit 700 outputs a request for prohibiting the output torque capacity control output to the second clutch CL2 to the AT controller 7 when a predetermined condition is satisfied.

  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.

  The mode selection unit 200 includes a road surface gradient estimation calculation unit 201 that estimates a road surface gradient based on the detection value of the G sensor 10b. The road surface gradient estimation calculation unit 201 calculates the actual acceleration from the wheel speed acceleration average value of the wheel speed sensor 19 and the like, and estimates the road surface gradient from the deviation between the calculation result and the G sensor detection value.

  Furthermore, the mode selection unit 200 includes a mode map selection unit 202 that selects one of two mode maps described later based on the estimated road surface gradient. FIG. 4 is a schematic diagram illustrating the selection logic of the mode map selection unit 202. When the road surface gradient estimated from the state in which the normal mode map is selected exceeds the predetermined value g2, the mode map selection unit 202 switches to the gradient road corresponding mode map. On the other hand, when the road surface gradient estimated from the state in which the gradient road corresponding mode map is selected becomes less than the predetermined value g1 (<g2), the mode is switched to the normal mode map. That is, a hysteresis is provided for the estimated road surface gradient to prevent control hunting at map switching.

  Next, the mode map will be described. The mode map includes a normal mode map that is selected when the estimated road surface gradient is less than a predetermined value, and a gradient road corresponding mode map that is selected when the estimated road surface gradient is greater than or equal to a predetermined value. FIG. 5 shows a normal mode map, and FIG. 6 shows a gradient road corresponding mode map.

  The normal mode map has an EV travel mode, a WSC travel mode, and an HEV travel mode, and calculates the target mode 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 normal mode map of FIG. 5, the HEV → WSC switching line has a rotational speed 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 lower limit 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 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 gradient road mode map differs from the normal mode map in that the EV drive mode area is not set. Further, the WSC travel mode area is different from the normal mode map in that the area is not changed according to the accelerator pedal opening APO and the area is defined only by the lower limit vehicle speed VSP1.

  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 normal mode map of FIG. Once the EV area appears in the mode map, it continues to appear until the SOC drops below 35%.

  When SOC <35%, the EV drive mode area disappears in the normal 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 calculates a judder generation determination threshold value for calculating a judder generation determination threshold value in increasing the transmission torque capacity of the second clutch CL2 in the WSC traveling mode in which the vehicle starts while slipping the second clutch CL2. Unit 401, and a clutch change rate limit value calculation unit 402 that calculates an upper limit value of the increase speed when the transmission torque capacity in the judder generation area increases, that is, a clutch change rate limit value that is a change rate limit value. Details will be described later. 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.

[About WSC drive mode]
Next, details of the WSC travel mode will be described. The WSC travel mode is characterized in that the engine E is maintained in an operating state, and has high responsiveness to changes in driver request torque. Specifically, the first clutch CL1 is completely engaged, the second clutch CL2 is slip-controlled as the transmission torque capacity TCL2 corresponding to the driver request torque, and the vehicle travels using the driving force of the engine E and / or the motor generator MG. .

  In the hybrid vehicle of the first embodiment, there is no element that absorbs the difference in rotational speed unlike the torque converter. Therefore, when the first clutch CL1 and the second clutch CL2 are completely engaged, the vehicle speed is determined according to the rotational speed of the engine E. End up. The engine E has a lower limit value based on the idling engine speed for maintaining the self-sustaining rotation, and the idling engine speed further increases when the engine is idling up due to warm-up operation of the engine. Further, when the driver required torque is high, there may be a case where the HEV traveling mode cannot be quickly changed.

  On the other hand, in the EV travel mode, since the first clutch CL1 is released, there is no limit associated with the lower limit value due to the engine speed. However, in the case where it is difficult to travel in the EV travel mode due to the restriction based on the battery SOC, or in a region where the driver required torque cannot be achieved only by the motor generator MG, there is no means other than generating stable torque by the engine E.

  Therefore, in a vehicle speed range lower than the vehicle speed corresponding to the lower limit value, and when it is difficult to travel in the EV travel mode, or in a region where the driver required torque cannot be achieved only by the motor generator MG, the engine speed is set to a predetermined value. While maintaining the lower limit rotational speed, the second clutch CL2 is slip-controlled, and the WSC traveling mode for traveling using the engine torque is selected.

  FIG. 8 is a schematic diagram showing the engine operating point setting process in the WSC running mode, and FIG. 9 is a map showing the engine target speed in the WSC running mode. When the driver operates the accelerator pedal in the WSC travel mode, the target engine speed characteristic corresponding to the accelerator pedal opening is selected based on FIG. 9, and the target engine speed corresponding to the vehicle speed is set along this characteristic. Is done. Then, the target engine torque corresponding to the target engine speed is calculated by the engine operating point setting process shown in FIG.

  Here, the operating point of the engine E is defined as a point defined by the engine speed and the engine torque. As shown in FIG. 8, it is desirable that the engine operating point be operated on a line (hereinafter referred to as “α line”) connecting operating points with high output efficiency of the engine E.

  However, when the engine speed is set as described above, an operating point away from the α line is selected depending on the driver's accelerator pedal operation amount (driver required torque). Therefore, in order to bring the engine operating point closer to the α line, the target engine torque is feedforward controlled to a value that takes the α line into consideration.

  On the other hand, the motor generator MG executes the rotational speed feedback control using the set engine rotational speed as the target rotational speed. Since the engine E and the motor generator MG are now in a directly connected state, the motor generator MG is controlled so as to maintain the target rotational speed, so that the rotational speed of the engine E is also automatically feedback-controlled. It becomes.

  At this time, the torque output from motor generator MG is automatically controlled so as to fill the deviation between the target engine torque determined in consideration of the α-ray and the driver request torque. In the motor generator MG, a basic torque control amount (regeneration / power running) is given so as to fill the deviation, and further feedback control is performed so as to match the target engine speed.

  When the driver required torque is smaller than the driving force on the α line at a certain engine speed, the engine output efficiency increases as the engine output torque is increased. At this time, by collecting the energy corresponding to the increased output by the motor generator MG, the torque itself input to the second clutch CL2 becomes the driver request torque, and efficient power generation is possible. However, since the upper limit of torque that can be generated is determined according to the state of the battery SOC, the required power generation output (SOC required power generation power) from the battery SOC and the deviation between the torque at the current operating point and the torque on the α line (α It is necessary to consider the magnitude relationship with the (line generated power).

  FIG. 8A is a schematic diagram when the α-ray generated power is larger than the SOC required generated power. Since the engine output torque cannot be increased above the SOC required power generation, the operating point cannot be moved on the α line. However, fuel efficiency is improved by moving to a more efficient point.

  FIG. 8B is a schematic diagram when the α-ray generated power is smaller than the SOC required generated power. Since the engine operating point can be moved on the α line within the SOC required power generation range, in this case, it is possible to generate power while maintaining the operating point with the highest fuel efficiency.

  FIG. 8C is a schematic diagram when the engine operating point is higher than the α line. When the operating point corresponding to the driver required torque is higher than the α line, the engine torque is reduced on the condition that the battery SOC has a margin, and the shortage is compensated by the power running of the motor generator MG. As a result, the driver required torque can be achieved while improving the fuel efficiency.

  Next, the point that the WSC traveling mode area is changed according to the estimated gradient will be described. FIG. 9 is an engine speed map when the vehicle speed is increased in a predetermined state. When the accelerator pedal opening is larger than APO1 on a flat road, the WSC drive mode region is executed up to a vehicle speed region higher than the lower limit vehicle speed VSP1. At this time, as the vehicle speed increases, the target engine speed gradually increases as shown in the map of FIG. Then, when the vehicle speed corresponding to VSP1 ′ is reached, the slip state of the second clutch CL2 is canceled and the state transits to the HEV travel mode.

  If the estimated road surface gradient is larger than a predetermined gradient (g1 or g2) and the same vehicle speed increase state as described above is to be maintained, the accelerator pedal opening is increased accordingly. At this time, the transmission torque capacity TCL2 of the second clutch CL2 is larger than that on a flat road. In this state, if the WSC travel mode region is enlarged as shown in the map shown in FIG. 5, the second clutch CL2 will continue to slip with a strong engagement force, and the amount of heat generated may be excessive. is there. Therefore, in the gradient road corresponding mode map shown in FIG. 6 selected when the estimated road surface gradient is large, the WSC travel mode region is not expanded unnecessarily, but the region corresponding to the vehicle speed VSP1. This avoids excessive heat generation in the WSC travel mode.

(Clutch torque increase control when starting)
Next, increase control of the transmission torque capacity of the second clutch CL2 at the time of start will be described. When the vehicle starts to move on the basis of the start intention of the driver, the Akuserupeda Le is depressed, the target drive torque is increased. At this time, the operating point command unit 400 calculates a transient target second clutch transmission torque capacity TCL2 * (hereinafter referred to as transmission torque capacity), and outputs a drive torque corresponding to the transmission torque capacity. . Here, when increasing the transmission torque capacity, it is preferable to increase the transmission torque capacity as quickly as possible in order to be able to start quickly according to the driver's intention. However, if the rising gradient of the transmission torque capacity is too large, judder is generated in the second clutch CL2, which may give the driver a sense of discomfort. Therefore, in the first embodiment, in a region where judder is not generated as the transmission torque capacity of the second clutch CL2 (that is, a region below the torque threshold), the transmission torque capacity is quickly increased according to the driver's intention, and judder may occur. In a certain region (region larger than the torque threshold), the speed of increase of the transmission torque capacity is limited and gradually increased.

  [Setting the judder occurrence determination threshold]

FIG. 11 is a block diagram illustrating a configuration of a judder generation determination threshold value calculation unit according to the first embodiment.
In the bush elasticity threshold value calculation unit 401a, a value at which the elasticity of the rubber bush of the vehicle driving force transmission system disappears is calculated as a torque threshold value. FIG. 14 is a schematic perspective view illustrating a configuration of a suspension member attached to the vehicle driving force transmission system of the first embodiment. There are four suspension members SM that constitute a suspension (specifically, a suspension arm SA and a shock absorber SHAB) provided between the left rear wheel RL (drive wheel), the right rear wheel RR (drive wheel), and the vehicle body. It is attached to the vehicle body via a rubber bush GB which is an elastic bush provided at a location. The suspension member SM holds a differential gear DF from which drive wheels are driven via a drive shaft.

  At this time, the judder occurrence determination threshold value is an inelastic region in which the deformation region of the rubber bush GB during vehicle acceleration changes nonlinearly from an elastic region in which the rubber bush GB deforms linearly with respect to a load acting on the rubber bush GB. Is set as the transmission torque capacity to switch to.

  That is, in the vehicle driving force transmission system, when torque is generated during vehicle acceleration, the drive shaft is twisted. At this time, a reaction also acts on the suspension member SM that supports the differential gear DF, and the rubber bush GB is deformed. While the rubber bush GB is deformed, judder can be suppressed. However, when the deformation of the rubber bush GB is finished, that is, when the elastic region is changed to the non-elastic region, the further twist is directly rebounded. Causes judder. Therefore, the value of the transmission torque capacity at which the rubber bush GB is switched from the elastic region to the inelastic region is calculated as one of the torque threshold values in the judder generation region.

  The gradient threshold value calculation unit 401b calculates a torque threshold value based on the road surface gradient estimated by the road surface gradient estimation calculation unit 201. That is, while traveling on a road surface with a large gradient, the load acting on the vehicle is large, and the time during which the second clutch CL2 is slipping increases and judder is likely to occur. Therefore, judder generation is suppressed by calculating a lower torque threshold value as the road surface gradient is larger.

  The towing amount threshold value calculation unit 401c calculates a torque threshold value based on the towing amount calculated by the towing amount calculation unit 101. That is, when the towing amount is large, the load acting on the vehicle is large, and the time during which the second clutch CL2 is slipping increases, so that judder is likely to occur. Therefore, judder generation is suppressed by calculating a lower torque threshold as the towing amount increases.

  The clutch plate temperature threshold value calculation unit 401d calculates a torque threshold value based on the clutch plate temperature calculated by the clutch plate temperature calculation unit 102. That is, the μ-V characteristic representing the relationship between the dynamic friction coefficient of the clutch plate and the slip amount varies depending on the temperature of the clutch plate. For example, when the slip amount is kept constant and the μ-V characteristic has a positive gradient at this point, if the μ-V characteristic changes to a negative gradient due to the temperature rise of the clutch plate, the transmission torque capacity increases rapidly. It becomes large and tends to cause judder. Therefore, by calculating a lower torque threshold as the clutch plate temperature is higher, the occurrence of judder is suppressed.

  The clutch plate deterioration degree threshold calculation unit 401e calculates a torque threshold based on the clutch plate deterioration degree calculated by the clutch plate deterioration degree calculation unit 103. In this case as well, the μ-V characteristic changes according to the degree of deterioration, as described in the clutch plate temperature threshold value calculation unit 401d. Therefore, judder generation is suppressed by calculating a lower torque threshold value as the degree of deterioration increases.

  The judder generation determination threshold setting unit 401f sets the smallest torque threshold among the torque thresholds calculated by the setting units 401a to 401e as the final judder generation determination threshold.

[Clutch change rate limit value in judder generation area]
FIG. 12 is a block diagram illustrating the configuration of the clutch change rate limit value calculation unit according to the first embodiment.
The gradient limit value calculation unit 402a calculates a clutch change rate limit value, which is an increase speed limit value of the transmission torque capacity, based on the road surface gradient estimated by the road surface gradient estimation calculation unit 201. That is, when the road surface gradient is large, the load acting on the vehicle is large, and the time during which the second clutch CL2 is slipping increases, so that judder is likely to occur. On the other hand, when the road surface gradient is small, the load acting on the vehicle is small and the time during which the second clutch CL2 is slipping is also short, so judder is unlikely to occur. Therefore, by calculating a larger clutch change rate limit value as the road surface gradient is smaller, occurrence of judder is suppressed while ensuring drivability.

  The towing amount limit value calculation unit 402b calculates a clutch change rate limit value based on the towing amount calculated by the towing amount calculation unit 101. That is, when the towing amount is large, the load acting on the vehicle is large, and the time during which the second clutch CL2 is slipping increases, so that judder is likely to occur. On the other hand, when the towing amount is small, the load acting on the vehicle is small, and the time during which the second clutch CL2 is slipping is also short, so judder is unlikely to occur. Therefore, by calculating a clutch change rate limit value that is larger as the towing amount is smaller, judder generation is suppressed while ensuring drivability.

  The clutch plate temperature limit value calculation unit 402c calculates a clutch change rate limit value based on the clutch plate temperature calculated by the clutch plate temperature calculation unit 102. That is, the μ-V characteristic representing the relationship between the dynamic friction coefficient of the clutch plate and the slip amount changes depending on the temperature of the clutch plate, and becomes unstable as the temperature increases. Therefore, by calculating a larger clutch change rate limit value as the clutch plate temperature is lower, judder generation is suppressed while ensuring drivability.

  The clutch plate deterioration degree limit value calculation unit 402d calculates a clutch change rate limit value based on the clutch plate deterioration degree calculated by the clutch plate deterioration degree calculation unit 103. That is, the μ-V characteristic representing the relationship between the dynamic friction coefficient of the clutch plate and the slip amount becomes unstable as the deterioration of the clutch plate proceeds. Therefore, by calculating a larger clutch change rate limit value as the clutch plate deterioration degree is lower, judder generation is suppressed while ensuring drivability.

  The accelerator opening limit value gain calculation unit 402e calculates an opening gain based on the accelerator opening. That is, when the accelerator opening is large, the driver requires a large acceleration, and when the accelerator opening is small, a small acceleration is required. Therefore, the larger the accelerator opening, the larger the opening gain is set. This ensures the drivability by reflecting the driver's intention.

The first limit value setting unit 402f sets the smallest limit value among the limit values calculated by the calculation units 402a to 402d.
In the second limit value setting unit 402g, the smallest limit value set in the first limit value setting unit 402f is multiplied by the opening degree gain calculated in the accelerator opening limit value gain calculating unit 402e to obtain the final clutch change. Calculate the rate limit value.

  FIG. 13 is a time chart showing the starting clutch torque increase control process of the first embodiment. The initial condition is that the vehicle is stopped in the WSC travel mode on a flat road, the clutch temperature is increased, and the clutch plate is also deteriorated to some extent. Engine E is in a state where it is maintained at an idle rotational speed by controlling the rotational speed of motor generator MG. Further, a transmission torque capacity corresponding to creep torque is set for the second clutch CL2.

  When the driver depresses the accelerator pedal at time t1, the transmission torque capacity of the second clutch CL2 according to the accelerator opening is set, and is transmitted to the drive wheels by the increasing gradient of the transmission torque capacity according to the driver's intention. Torque increases. At this time, since it is the WSC traveling mode, as shown in the map of FIG. 9, the motor generator MG is set with the target motor generator rotational speed corresponding to the vehicle speed, and the engine torque and the motor are maintained so as to maintain this rotational speed. Generator torque is output.

  When the transmission torque capacity of the second clutch CL2 reaches the judder occurrence determination threshold at time t2, thereafter, the transmission torque capacity with the clutch change rate limit value calculated by the clutch change rate limit value calculation unit 402 as the upper limit is set. Increases speed. That is, in the judder generation region, the rate of increase of the transmission torque capacity is limited, so that judder generation can be suppressed. On the other hand, the clutch change rate according to the driver's intention can be obtained until the judder occurrence determination threshold value, and drivability can be ensured.

At time t3, when the transmission torque capacity reaches the target transmission torque capacity determined from the accelerator opening, the driving speed according to the transmission torque capacity is transmitted to the drive wheels, so that the vehicle speed increases, and accordingly, at the input rotational speed. A certain motor generator rotational speed also increases (see FIG. 9).
Then, when the slip in the second clutch CL2 ends at time t4, the WSC traveling mode is changed to the HEV traveling mode, and the second clutch CL2 is brought into a completely engaged state.
The initial condition of the time chart shown in FIG. 13 shows an example of the clutch temperature rise on a flat road. However, the same applies to a case of a slope road, a towing, and a clutch plate deterioration. The rate limit value is also limited in the same manner, and the substantial action is the same.

As described above, in the hybrid vehicle of the first embodiment, the following effects can be obtained.
(1) An engine E and a motor generator MG (power source) that output driving torque to the driving wheels, and a second clutch CL2 that is interposed between the motor generator MG and the driving wheels and connects and disconnects the motor generator MG and the driving wheels. (Clutch), an integrated controller 10 (clutch control means) for increasing the transmission torque capacity of the second clutch CL2 in the WSC travel mode in which the second clutch CL2 is slipped according to the driver's intention, and the second clutch CL2 When the transmission torque capacity is increased, the transmission torque capacity of the second clutch CL2 is equal to or greater than the judder generation determination threshold value for determining whether or not the vehicle is in the judder generation region, and the transmission torque capacity is the judder generation region The increase rate of the transmission torque capacity is higher than the increase speed of the transmission torque capacity when the transmission torque capacity is less than the judder generation determination threshold. Clutch change rate limit value calculating unit 402 which fence (the clutch change rate limiting means), with a.

  Therefore, driving performance is ensured by increasing the transmission torque capacity according to the driver's intention up to the judder generation determination threshold, and generation of judder is suppressed by suppressing an increase in the transmission torque capacity above the judder generation determination threshold. can do.

  (2) The suspension member SM of the suspension provided between the wheel and the vehicle body is attached to the vehicle body via a rubber bush GB (elastic bush), and the judder occurrence determination threshold is the deformation of the rubber bush GB during vehicle acceleration. The region is a transmission torque capacity that switches from an elastic region in which the rubber bush GB is linearly deformed to a load acting on the rubber bush GB to an inelastic region that changes nonlinearly (bush elastic threshold calculation unit 401a). Therefore, it is possible to suppress judder by suppressing the increase rate of the transmission torque capacity in a region where judder is likely to occur.

  (3) It has a road surface gradient estimation calculation unit 201 (road surface gradient detection means) for detecting a road surface gradient, and the judder generation determination threshold value is set to a lower value as the detected road surface gradient is larger (road surface gradient threshold value calculation unit 401b). ). Therefore, even if the road surface gradient is large and the slip time becomes long, the occurrence of judder can be suppressed.

  (4) It has a towing amount calculation unit 101 (towing amount detection means) for detecting the towing amount, and the judder generation determination threshold value is set to a lower value as the detected towing amount is larger (towing amount threshold value calculation unit 401c). Therefore, even if the towing amount is large and the slip time becomes long, the occurrence of judder can be suppressed.

  (5) The clutch plate temperature calculation unit 102 (clutch plate temperature detection means) for detecting the clutch plate temperature of the second clutch CL2 is provided, and the judder generation determination threshold value is set to a lower value as the detected clutch plate temperature is higher. (Clutch plate temperature threshold value calculation unit 401d). Therefore, even if the clutch plate temperature is high and the μ-V characteristic becomes unstable, the occurrence of judder can be suppressed.

  (6) The clutch plate deterioration degree calculating unit 103 (clutch plate deterioration degree detecting means) for detecting the clutch plate deterioration degree of the second clutch CL2 is provided, and the judder occurrence determination threshold value is higher as the detected clutch plate deterioration degree is higher. Set to a low value. Therefore, even if the μ-V characteristic becomes unstable due to the deterioration of the clutch plate, the occurrence of judder can be suppressed.

  (7) It has a road surface gradient estimation calculation unit 201 (road surface gradient detection means) for detecting the road surface gradient, and the clutch change rate limit value calculation unit 402 increases the clutch at the judder generation determination threshold value or higher as the detected road surface gradient is smaller. The rate of change is increased (gradient limit value calculation unit 402a). Therefore, it is possible to suppress the occurrence of judder while ensuring drivability.

  (8) It has a towing amount calculation unit 101 (towing amount detection means) for detecting the towing amount, and the clutch change rate limit value calculation unit 402 has a clutch change rate equal to or higher than the judder occurrence determination threshold as the detected towing amount decreases. Is increased (towing amount limit value calculation unit 402b). Therefore, it is possible to suppress the occurrence of judder while ensuring drivability.

  (9) The clutch plate temperature calculation unit 102 (clutch plate temperature detection means) for detecting the clutch plate temperature of the second clutch CL2 is provided, and the clutch change rate limit calculation unit 402 has a judder as the detected clutch plate temperature is lower. Increase the clutch change rate above the occurrence determination threshold (clutch plate temperature limit value calculation unit 402c). Therefore, it is possible to suppress the occurrence of judder while ensuring drivability.

  (10) The clutch plate deterioration degree calculating unit 103 (clutch plate deterioration degree detecting means) for detecting the clutch plate deterioration degree of the second clutch CL2 is included, and the clutch change rate limit calculating part 402 has the detected clutch plate deterioration degree. The lower the value, the larger the clutch change rate at the judder occurrence determination threshold value or higher (clutch plate deterioration degree limit value calculation unit 402d). Therefore, it is possible to suppress the occurrence of judder while ensuring drivability.

  (11) The clutch change rate limit calculation unit 402 increases the clutch change rate at or above the judder occurrence determination threshold as the accelerator pedal opening increases (accelerator opening limit value gain calculation unit 402e). Therefore, the driver's intention can be reflected and drivability can be ensured.

  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, but the present invention can be similarly applied to a vehicle having only an engine or only a motor. In the first embodiment, the FR type hybrid vehicle has been described. However, an FF type hybrid vehicle may be used.

  In the first embodiment, the judder generation determination threshold setting unit 401f is configured to set the smallest torque threshold among the torque thresholds calculated by the setting units 401a to 401e as the final judder generation determination threshold. However, the effect of the present invention can be obtained even if any one or more of the above-described setting units is set appropriately.

E engine
CL1 1st clutch
MG motor generator
CL2 2nd clutch
AT automatic transmission SM suspension member GB rubber bush 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 (11)

A power source that outputs drive torque to the drive wheels;
A clutch interposed disconnecting and said power source and said drive wheel between the power source and the driving wheels,
Clutch control means for increasing the transmission torque capacity of the clutch at the time of control for slipping the clutch according to the driver's intention;
When increasing the transmission torque capacity of the clutch, the transmission torque capacity of the clutch becomes equal to or greater than a judder generation determination threshold for determining whether or not the vehicle is in a region where judder is generated, and the transmission torque capacity is Clutch change rate limiting means for making the increase rate of the transfer torque capacity smaller than the increase speed of the transfer torque capacity when the transfer torque capacity is less than the judder occurrence determination threshold when in the region;
A vehicle control device comprising: The vehicle control device according to claim 1,
A suspension member of a suspension provided between the wheel and the vehicle body is attached to the vehicle body via an elastic bush,
The judder occurrence determination threshold is determined by switching a deformation region of the elastic bush during vehicle acceleration from an elastic region in which the elastic bush is linearly deformed to a load acting on the elastic bush to a non-elastic region that changes nonlinearly. A vehicle control device characterized by having a transmission torque capacity to be changed. The vehicle control device according to claim 1 or 2,
Having road surface gradient detecting means for detecting the road surface gradient,
The judder generation determination threshold value is set to a lower value as the detected road surface gradient is larger. The vehicle control device according to any one of claims 1 to 3,
Having a towing amount detecting means for detecting the towing amount;
The judder occurrence determination threshold value is set to a lower value as the detected towing amount is larger. The vehicle control device according to any one of claims 1 to 4,
Clutch plate temperature detecting means for detecting the clutch plate temperature of the clutch;
The judder generation determination threshold value is set to a lower value as the detected clutch plate temperature is higher. The vehicle control device according to any one of claims 1 to 5,
Clutch plate deterioration degree detecting means for detecting the clutch plate deterioration degree of the clutch;
The judder occurrence determination threshold value is set to a lower value as the detected clutch plate deterioration degree is higher. The vehicle control device according to any one of claims 1 to 6,
Having road surface gradient detecting means for detecting the road surface gradient,
The clutch change rate limiting means increases the clutch change rate at or above the judder generation determination threshold as the detected road surface gradient is smaller. The vehicle control device according to any one of claims 1 to 7,
Having a towing amount detecting means for detecting the towing amount;
The clutch change rate limiting means increases the clutch change rate at or above the judder occurrence determination threshold as the detected towing amount is smaller. The vehicle control device according to any one of claims 1 to 8,
Clutch plate temperature detecting means for detecting the clutch plate temperature of the clutch;
The vehicle control apparatus characterized in that the clutch change rate limiting means increases the clutch change rate above the judder generation determination threshold as the detected clutch plate temperature is lower. The vehicle control device according to any one of claims 1 to 9,
Clutch plate deterioration degree detecting means for detecting the clutch plate deterioration degree of the clutch;
The vehicle control device according to claim 1, wherein the clutch change rate limiting means increases the clutch change rate at or above the judder occurrence determination threshold as the detected degree of deterioration of the clutch plate is lower. The vehicle control device according to any one of claims 1 to 10,
The vehicle control apparatus according to claim 1, wherein the clutch change rate limiting means increases the clutch change rate at or above the judder occurrence determination threshold as the accelerator pedal opening is larger.

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