JP2013126365A - Vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more appropriately suppress vibration due to a driving wheel speed when lock suppression control of a brake device is executed.SOLUTION: When ABS control is executed by a brake ECU for preventing slippage due to wheel lock caused by braking operation during traveling (time t1), and a slip speed Vs obtained by subtracting a driving wheel speed Vd from a presumed vehicle body speed Vb reaches a torque output threshold or more (time t2), as torque for matching the driving wheel speed Vd to the presumed vehicle body speed Vb, basic torque is set so as to become larger as a maximum slip speed Vsmax which is a maximum value of the slip speed Vs after the ABS control is executed gets larger, and the torque corresponding to the basic torque is output from a motor (time t2 to t5). As a result, the torque based on the maximum slip speed Vsmax without vibration is output from the motor as compared to a case where the torque based on the slip speed Vs with vibration is output from the motor.

Description

  The present invention relates to a vehicle, and more particularly, a motor capable of inputting / outputting power to / from a drive shaft connected to a drive wheel, a battery capable of exchanging electric power with the motor, and depending on a brake operation or regardless of a brake operation. The present invention relates to a vehicle including a brake device capable of applying a braking force to the vehicle, and a brake control unit that executes lock suppression control of the brake device that suppresses slip due to wheel locking based on a brake operation during traveling.

  Conventionally, this type of vehicle includes a motor that outputs a driving force to an axle to which driving wheels are connected, an electronically controlled brake device that applies a braking force to each wheel according to a brake pedal force, and a slip ratio of the wheel. When the vehicle exceeds a predetermined judgment value, it is judged that the vehicle is in a locked state, and an anti-lock brake system (ABS) is operated to reduce the brake pressure of the wheel, and the brake pressure is reduced by the ABS. In addition, another controller that outputs a relatively large driving torque from a motor has been proposed (see, for example, Patent Document 1). In this vehicle, the driving torque output from the motor during the operation of the ABS by locking the driving wheel is obtained by subtracting the actual wheel speed (actual slip wheel speed) at the start of adding the driving torque from the target wheel speed corresponding to the estimated vehicle speed. By setting a torque proportional to the deviation and controlling the set torque to be output only for a certain period of time, the rotation of the locked drive wheel is restored early.

JP 2006-333665 A

  In the vehicle having the above-described configuration, when the ABS is actuated by depressing the brake pedal while traveling on a traveling road having a small friction coefficient (so-called low μ road), the driving shaft to which the motor is connected and the axle to which the driving wheel is connected. The torsion of the shaft is promoted between and the speed of the drive wheel vibrates. For example, when the speed of the drive wheel is temporarily greatly reduced, it is determined that the slip amount exceeds the threshold, and the brake pressure is reduced by ABS. In some cases, the braking distance until the vehicle stops becomes longer. In this case, as in the vehicle described above, it is also conceivable to output the driving side (positive side) torque from the motor so that the speed of the driving wheel coincides with the vehicle body speed, that is, the driving wheel is in the grip state. However, when a torque proportional to the deviation between the vehicle speed and the driving wheel speed is output from the motor, the vibration (amplitude) of the driving wheel speed is promoted depending on the phase of the output torque of the motor. Inconvenience may be noticeable.

  The vehicle of the present invention is mainly intended to more appropriately suppress the vibration of the speed of the drive wheels when the brake device lock suppression control is executed.

  The vehicle of the present invention employs the following means in order to achieve the main object described above.

The vehicle of the present invention
A motor capable of inputting / outputting power to / from a drive shaft connected to a drive wheel, a battery capable of exchanging electric power with the motor, and a brake capable of applying braking force to the vehicle according to or regardless of the brake operation A vehicle, and a brake control unit that executes lock suppression control of the brake device that suppresses slippage due to locking of a wheel based on a brake operation during traveling,
When the lock suppression control is executed and the slip amount reflecting the speed difference obtained by subtracting the speed of the drive wheel from the vehicle speed becomes equal to or greater than a predetermined torque output threshold, the speed of the drive wheel is set to the vehicle speed. As the torque for matching, the return torque is set so as to increase as the maximum slip amount, which is the maximum value of the slip amount after the lock suppression control is executed, increases, and the set return torque is set. Motor control means for controlling the motor so that is output from the motor;
It is a summary to provide.

  In the vehicle according to the present invention, the slip suppression amount that reflects the speed difference obtained by subtracting the speed of the drive wheel from the vehicle body speed is executed while the lock suppression control of the brake device that suppresses the slip due to the wheel lock based on the brake operation during traveling is executed. Is equal to or greater than a predetermined torque output threshold, the maximum slip amount, which is the maximum value of the slip amount after the lock suppression control is executed, is used as the torque for matching the speed of the drive wheels to the vehicle body speed. The return torque is set so as to increase as the value increases, and the motor is controlled so that the set return torque is output from the motor. Therefore, since the return torque corresponding to the maximum slip amount, which is the maximum value after the lock suppression control is executed as the torque for matching the speed of the drive wheel with the vehicle body speed, is output from the motor, the speed of the drive wheel Unlike the case where the torque corresponding to the slip amount is outputted from the motor as the torque for matching the vehicle speed with the vehicle body speed, the vibration (amplitude) of the driving wheel speed is not promoted by the torque from the motor. it can. Further, by matching the speed of the driving wheel with the vehicle body speed, the driving wheel can be brought into a grip state, and vibration of the driving wheel speed can be suppressed. As a result, it is possible to more appropriately suppress the vibration of the speed of the drive wheels when the lock suppression control of the brake device is executed. Here, the torque output threshold value may be a predetermined threshold value for determining a state in which the driving wheel speed is greatly reduced and vibration of the driving wheel speed is generated.

  In such a vehicle of the present invention, the return torque may be a torque for making the speed of the driving wheel coincide with the vehicle body speed at a predetermined return timing. In this way, it is possible to suppress the behavior of the vehicle from being different due to the timing at which the speed of the driving wheel coincides with the vehicle body speed. Here, the predetermined return timing may be a timing at which a predetermined time elapses from when the maximum slip amount becomes a constant value.

  In the vehicle of the present invention, the motor control means may perform the lock suppression control and, after the slip amount becomes equal to or greater than the torque output threshold, the slip amount is less than a predetermined torque reduction threshold. In this case, the motor may be controlled so that a torque obtained by multiplying the return torque by a coefficient that becomes smaller than the value 1 as the slip amount is smaller is output from the motor. By doing so, it is possible to suppress the speed of the drive wheels from exceeding the vehicle body speed by outputting the return torque from the motor in a state where the slip amount is small. Here, the torque reduction threshold value may be a predetermined threshold value for suppressing the speed of the driving wheel from exceeding the vehicle body speed.

  Further, in the vehicle according to the present invention, the motor control means outputs the torque output with the slip amount smaller than the torque output threshold after the lock suppression control is executed and the slip amount becomes equal to or greater than the torque output threshold. It may be a means for controlling the motor so that the output of the return torque from the motor is stopped when it becomes less than the stop threshold. In this way, it is possible to suppress the occurrence of hunting in which the output of torque from the motor and the output stop are frequently repeated.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. It is a flowchart which shows an example of the motor control routine at the time of the ABS action | operation performed by HVECU70 of an Example. It is explanatory drawing which shows an example of the map for basic torque setting. It is explanatory drawing which shows an example of the map for a load factor setting. It is explanatory drawing which shows an example of the mode change of the estimated vehicle body speed Vb, the driving wheel speed Vd, the positive torque output flag F, the slip speed Vs, the maximum slip speed Vsmax, the load factor R, and the motor torque Tm2 during the ABS operation. . FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. It is a block diagram which shows the outline of a structure of the electric vehicle 220 of a modification.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22 configured as an internal combustion engine using gasoline, light oil, or the like as a fuel, and a signal from a crank position sensor (not shown) attached to a crankshaft 26 of the engine 22. A carrier is connected to an engine electronic control unit (hereinafter referred to as an engine ECU) 24 for operating the engine 22 by inputting signals from various sensors for detecting the state of the engine 22 and a crankshaft 26 as an output shaft of the engine 22. And a planetary gear 30 in which a ring gear is connected to the drive shaft 32 coupled to the drive wheels 63a and 63b via a differential gear 62, and a rotor connected to the sun gear of the planetary gear 30. For example, the same as motor MG1 A motor MG2 configured as a generator motor and having a rotor connected to the drive shaft 32, inverters 41 and 42 for driving the motors MG1 and MG2, and a rotation for detecting the rotational position of the rotors of the motors MG1 and MG2, for example. By inputting signals from various sensors for detecting the states of the motors MG1 and MG2 and the inverters 41 and 42 such as signals from the position detection sensors 43 and 44, the motors MG1 and MG2 are controlled by switching the switching elements of the inverters 41 and 42. And a battery 50 that is configured as a secondary battery such as a lithium ion battery and exchanges power with the motors MG1 and MG2 via inverters 41 and 42, for example. And battery electronic control for managing the battery 50 A unit (hereinafter referred to as a battery ECU) 52, a brake actuator 92 for controlling brakes of driving wheels 63a and 63b and driven wheels 64a and 64b (hereinafter also referred to as wheels), and a hybrid for controlling the entire vehicle An electronic control unit 70 (hereinafter referred to as HVECU) is provided.

  Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The engine ECU 24 receives signals from various sensors that detect the operating state of the engine 22, for example, a water temperature sensor that detects the crank position θcr from the crank position sensor that detects the rotational position of the crankshaft 26 and the coolant temperature of the engine 22. From the cam position sensor for detecting the cooling water temperature Tw from the cylinder, the in-cylinder pressure Pin from the pressure sensor installed in the combustion chamber, the rotational position of the intake valve for intake and exhaust to the combustion chamber and the camshaft for opening and closing the exhaust valve Position θca, throttle position SP from a throttle valve position sensor for detecting the position of the throttle valve, intake air amount Qa from an air flow meter attached to the intake pipe, intake air temperature Ta from a temperature sensor also attached to the intake pipe, Installed in the exhaust system The air-fuel ratio AF from the air-fuel ratio sensor and the oxygen signal O2 from the oxygen sensor attached to the exhaust system are input via the input port, and the engine ECU 24 is for driving the engine 22. Various control signals, such as the drive signal to the fuel injection valve, the drive signal to the throttle motor that adjusts the throttle valve position, the control signal to the ignition coil integrated with the igniter, and the opening / closing timing of the intake valve can be changed A control signal to the variable valve timing mechanism is output via the output port. The engine ECU 24 is in communication with the HVECU 70, controls the operation of the engine 22 by a control signal from the HVECU 70, and outputs data related to the operation state of the engine 22 to the HVECU 70 as necessary. The engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22 based on a signal from a crank position sensor (not shown) attached to the crankshaft 26.

  Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The motor ECU 40 receives signals necessary for driving and controlling the motors MG1 and MG2, for example, rotational positions θm1 and θm2 from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and not shown. A phase current applied to the motors MG1 and MG2 detected by the current sensor is input via the input port, and the motor ECU 40 outputs a switching control signal to switching elements (not shown) of the inverters 41 and 42. It is output through the port. The motor ECU 40 is in communication with the HVECU 70, controls the driving of the motors MG1 and MG2 by a control signal from the HVECU 70, and outputs data related to the operating state of the motors MG1 and MG2 to the HVECU 70 as necessary. The motor ECU 40 calculates the rotational angular velocities ωm1, ωm2 and the rotational speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 from the rotational position detection sensors 43, 44. Or the driving wheel rotational angular velocity ωb as the rotational angular velocity of the driving wheels 63a and 63b converted to the rotational shaft of the motor MG2 based on the rotational angular velocity ωm2 of the motor MG2. In the embodiment, the driving wheel rotation angular velocity ωb uses the zero-order hold at the control sample time with respect to the control system design model of the two-inertia system obtained by limiting to the characteristic between the motor MG2 and the driving wheels 63a and 63b. It is assumed that the calculation is performed using a discrete model.

  Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The battery ECU 52 receives signals necessary for managing the battery 50, for example, an inter-terminal voltage Vb from a voltage sensor (not shown) installed between the terminals of the battery 50 and a power line connected to the output terminal of the battery 50. The charging / discharging current Ib from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor (not shown) attached to the battery 50, and the like are input. Send to. Further, the battery ECU 52 is based on the integrated value of the charge / discharge current Ib detected by the current sensor in order to manage the battery 50, and the power storage ratio that is the ratio of the capacity of power that can be discharged from the battery 50 at that time to the total capacity The SOC is calculated, and the input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the battery 50, are calculated based on the calculated storage ratio SOC and the battery temperature Tb. The input / output limits Win and Wout of the battery 50 are set to the basic values of the input / output limits Win and Wout based on the battery temperature Tb, and the output limiting correction coefficient and the input limiting limit are set based on the storage ratio SOC of the battery 50. It can be set by setting a correction coefficient and multiplying the basic value of the set input / output limits Win and Wout by the correction coefficient.

  The brake actuator 92 has wheels (driving wheels 63a) corresponding to the brake share in the braking force applied to the vehicle by the pressure (brake pressure) of the brake master cylinder 90 and the vehicle speed V generated in response to depression of the brake pedal. , 63b and the driven wheels 64a, 64b), the hydraulic pressures of the brake wheel cylinders 96a to 96d are adjusted so that the braking force acts on the wheels regardless of the depression of the brake pedal. It is configured so that it can be adjusted. Hereinafter, the braking force applied to the wheel by the operation of the brake actuator 92 may be referred to as a hydraulic brake. The brake actuator 92 is controlled by a brake electronic control unit (hereinafter referred to as a brake ECU) 94. The brake ECU 94 includes left and right wheel speeds (hereinafter referred to as drive wheel speeds) Vdr and Vdl from the wheel speed sensors 98a and 98b attached to the drive wheels 63a and 63b, and wheel speed sensors 98c attached to the driven wheels 64a and 64b. , 98d, and left and right wheel speeds (hereinafter referred to as driven wheel speeds) Vnr, Vnl, a steering angle signal from a steering angle sensor (not shown), and the like, and when the driver depresses the brake pedal, the driving wheel 63a 63b and driven wheels 64a and 64b are prevented from slipping due to locking, and any of the driving wheels 63a and 63b is caused by idling when the driver depresses the accelerator pedal. Traction control (TRC) to prevent slipping, attitude when the vehicle is turning Such control to maintain the posture for holding (VSC) is also performed. The brake ECU 94 is in communication with the HVECU 70, and controls the drive of the brake actuator 92 by a control signal from the HVECU 70, and outputs data related to the state of the brake actuator 92 to the HVECU 70 as necessary.

  The HVECU 70 is configured as a microprocessor centered on the CPU 72, and includes a ROM 74 that stores a processing program, a RAM 76 that temporarily stores data, an input / output port and a communication port (not shown), in addition to the CPU 72. The HVECU 70 includes an ignition signal from the ignition switch 80, a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever, an accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal, The brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. The HVECU 70 is connected to the engine ECU 24, the motor ECU 40, the battery ECU 52, and the brake ECU 92 via a communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, the battery ECU 52, and the brake ECU 94. .

  The thus configured hybrid vehicle 20 of the embodiment calculates the required torque Tr * to be output to the drive shaft 32 based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal by the driver. The operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque Tr * is output to the drive shaft 32. As the operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is transmitted to the planetary gear 30 and the motor MG1. And a motor MG2 to convert the torque and output to the drive shaft 32. The torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2, and the power suitable for the sum of the required power and the power required for charging and discharging the battery 50 Is controlled so that the engine 22 is output from the engine 22, and all or a part of the power output from the engine 22 with charging / discharging of the battery 50 is converted by the planetary gear 30, the motor MG1, and the motor MG2. So that the required power is output to the drive shaft 32. Charge-discharge drive mode for driving and controlling over data MG1 and the motor MG2, there is a motor operation mode in which operation control to output a power commensurate to stop the operation of the engine 22 to the required power from the motor MG2 to the drive shaft 32. The torque conversion operation mode and the charge / discharge operation mode are modes in which the engine 22 and the motors MG1 and MG2 are controlled so that the required power is output to the drive shaft 32 with the operation of the engine 22. Since there is no difference in general control, both are hereinafter referred to as an engine operation mode.

  In the engine operation mode, the HVECU 70 sets the required torque Tr * to be output to the drive shaft 32 based on the accelerator opening Acc from the accelerator pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88, and the set required torque The travel power Pdrv * required for travel is calculated by multiplying Tr * by the rotational speed Nr of the drive shaft 32 (for example, the rotational speed Nm2 of the motor MG2 or the rotational speed obtained by multiplying the vehicle speed V by a conversion factor). The power to be output from the engine 22 by subtracting the charge / discharge required power Pb * (positive value when discharging from the battery 50) of the battery 50 obtained from the calculated traveling power Pdrv * based on the storage ratio SOC of the battery 50 Is set as the required power Pe *. Then, the target rotational speed Ne of the engine 22 is obtained using an operation line (for example, a fuel efficiency optimal operation line) as a relationship between the rotational speed Ne of the engine 22 and the torque Te that can efficiently output the required power Pe * from the engine 22. * And the target torque Te * are set, and the motor is controlled by the rotational speed feedback control so that the rotational speed Ne of the engine 22 becomes the target rotational speed Ne * within the range of the input / output limits Win and Wout of the battery 50. A torque command Tm1 * as a torque to be output from MG1 is set, and when the motor MG1 is driven by the torque command Tm1 *, the torque acting on the drive shaft 32 via the planetary gear 30 is subtracted from the required torque Tr * to reduce the motor MG2. Torque command Tm2 * is set, and the target rotational speed Ne * and target torque Te * are set. In its sent to the engine ECU 24, the torque command Tm1 *, the Tm2 * is sent to the motor ECU 40. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te *, controls the intake air amount, fuel injection control, and ignition of the engine 22 so that the engine 22 is operated by the target rotational speed Ne * and the target torque Te *. The motor ECU 40 that performs control or the like and receives the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *.

  In the motor operation mode, the HVECU 70 sets a required torque Tr * to be output to the drive shaft 32 based on the accelerator opening Acc and the vehicle speed V, sets a value 0 to the torque command Tm1 * of the motor MG1, and sets the battery 50. The torque command Tm2 * of the motor MG2 is set and transmitted to the motor ECU 40 so that the required torque Tr * is output to the drive shaft 32 within the range of the input / output limits Win, Wout. Then, the motor ECU 40 that receives the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *.

  Next, when the ABS control is executed by the operation of the hybrid vehicle 20 of the embodiment configured in this way, particularly by the depression of the brake pedal on a traveling road (so-called low μ road) where the friction coefficient between the wheel and the road surface is small. Next, the operation when suppressing the vibration of the driving wheel speed Vd will be described. FIG. 2 is a flowchart showing an example of an ABS operating motor control routine executed by the HVECU 70. This routine is repeatedly executed at predetermined time intervals (for example, every several msec) while the ABS control is being executed by the brake ECU 94. In the embodiment, the ABS control by the brake ECU 94 is a predetermined ABS based on the estimated vehicle speed Vb, which will be described later, from among the driving wheel speeds Vdr and Vdl and the driven wheel speeds Vnr and Vnl from the wheel speed sensors 98a to 98d. When it becomes smaller than the start threshold, it is started for the wheel corresponding to the reduced wheel speed, and the difference between the wheel speed and the estimated vehicle body speed Vb is stably within a predetermined range and a predetermined time has elapsed. When to finish. Further, in the embodiment, when the ABS control is executed, basically, it corresponds to the share of the motor MG2 among the share of the hydraulic brake and the share of the motor MG2 based on the depression amount of the brake pedal and the vehicle speed V. It is assumed that a torque obtained by limiting the regenerative torque (negative torque) with a predetermined lower limit (negative value) is output from the motor MG2. In the ABS control of the embodiment, whether or not to reduce the hydraulic pressure of the hydraulic brake of the corresponding wheel depending on whether or not the difference between the estimated vehicle body speed Vb and the wheel speed is equal to or less than a control threshold value greater than a predetermined ABS start threshold value. Was determined.

  When the ABS motor control routine is executed, the CPU 72 of the HVECU 70 first calculates the estimated vehicle speed Vb, which is the estimated vehicle speed, and the drive wheel speed Vdr of the drive wheels 63a, 63b from the wheel speed sensors 98a, 98b. , Vdl, and the like are input (step S100). Here, in the embodiment, the estimated vehicle speed Vb is estimated based on signals from the wheel speed sensors 98a to 98d, signals from the vehicle speed sensor 88, signals from an acceleration sensor (not shown) that detects vehicle acceleration, and the like. I was supposed to enter things. Now, since it is considered when ABS control is executed, there is a possibility that slip occurs in any of the wheels. However, in order to facilitate the explanation, in the embodiment, the left and right drive wheels 63a, The following description will be made on the assumption that both wheels slip when 63b slips. Therefore, the average value of driving wheel speeds Vdr and Vdl input in step S100 or one of the values is used as the driving wheel speed Vd in the following description.

  When the data is input in this way, the slip speed Vs of the drive wheels 63a and 63b is calculated by subtracting the drive wheel speed Vd from the input estimated vehicle body speed Vb (step S110), and the slip speed Vs after the ABS control is executed. Is determined as the maximum slip speed Vsmax (step S120). For the maximum slip speed Vsmax, the larger of the maximum slip speed Vsmax (previous Vsmax) obtained when this routine was executed last time and the slip speed Vs calculated when this routine was executed this time is set as the maximum slip speed Vsmax. It can be obtained by selecting.

  Subsequently, in order to make the driving wheel speed Vd coincide with the vehicle body speed Vb (that is, in order to return the driving wheels 63a and 63b to the grip state), whether or not the driving side (positive side) torque is output from the motor MG2. (Step S130), and when the positive torque output flag F is 0, the slip speed Vs is compared with a predetermined torque output threshold Vs1 (step S140). Here, the initial value of the positive torque output flag F is set to 0. When it is determined in this routine that the driving side torque is output from the motor MG2, the value 1 is set and the driving side from the motor MG2 is set to the driving side. This flag is set to a value of 0 when it is determined to stop the output of torque. In the embodiment, the torque output threshold value Vs1 is determined by experiment or analysis to determine that the driving wheel speed Vd is greatly decreased (rapidly decreased) and the driving wheel speed Vd may vibrate. A predetermined threshold value was used.

  When the slip speed Vs is less than the torque output threshold Vs1, the initial value positive torque output flag F is held, and when the slip speed Vs is equal to or higher than the torque output threshold Vs1, the driving torque is output from the motor MG2. Judgment is made and the value 1 is set to the positive torque output flag F (step S150). When the value 1 is set to the positive torque output flag F in this way, the next time this routine is executed, the positive torque output flag F is determined to be a value 1 in step S130, and is smaller than the slip speed Vs and the torque output threshold Vs1. The torque output stop threshold value Vs2 determined in advance as a value is compared (step S160). While the slip speed Vs is equal to or higher than the torque output stop threshold Vs2, the positive torque output flag F having a value of 1 is held, and when the slip speed Vs becomes less than the torque output stop threshold Vs2, the torque on the drive side from the motor MG2 It is determined that the output is to be stopped, and the value 0 is set to the positive torque output flag F (step S170). Thus, since it is determined whether or not to stop the output of torque on the driving side from the motor MG2 using the slip speed Vs2 smaller than the torque output threshold Vs1, the output of torque from the motor MG2 and the output stop are frequently repeated. The occurrence of hunting can be suppressed.

  When the positive torque output flag F is thus set, the set positive torque output flag F is checked (step S180). When the positive torque output flag F is 1, the driving wheel speed Vd is set to the estimated vehicle body speed Vb at a predetermined return timing. In order to match, the basic torque Tbase is set based on the maximum slip speed Vsmax as the driving-side torque output from the motor MG2 (step S190). Here, the basic torque Tbase is stored in the ROM 74 as a basic torque setting map by predetermining the relationship between the maximum slip speed Vsmax and the basic torque Tbase in the embodiment, and stored when the maximum slip speed Vsmax is given. The corresponding basic torque Tbase is derived from the map and set. FIG. 3 shows an example of the basic torque setting map. As shown in the drawing, the basic torque Tbase is determined to increase as the maximum slip speed Vsmax increases. From the equation of motion of the wheel at the time of slip, the equation of motion of the vehicle body at the time of slip, and the relational expression in which the wheel speed is the vehicle speed at a constant rate, the torque Tm to be basically output from the motor MG2 is It is based on what is expressed as equation (1). In the formula (1), the torque Tm is the slip speed Vs, the torque output time Ts from the motor MG2, the tire radius Rt of the drive wheels 63a and 63b, the road surface dynamic friction coefficient μ, the vehicle overall weight Mg, the vehicle drive wheel side (For example, front side) Weight mg, body inertia moment Ib, tire inertia moment It of driving wheels 63a and 63b, braking force Fb acting on driving wheels 63a and 63b, and gear ratio G of differential gear 62 are calculated. If average values are used as the dynamic friction coefficient μ and the braking force F in the equation (1), it can be seen that the torque Tm is expressed as a linear function with the slip speed Vs as a variable. The reason for using the maximum slip speed Vsmax instead of the slip speed Vs to set the basic torque Tbase will be described later. As a predetermined return timing for making the driving wheel speed Vd coincide with the estimated vehicle body speed Vb, in the embodiment, a predetermined time (for example, 80 ms or 100 ms) elapses from when the maximum slip speed Vsmax becomes a constant value. Timing was used. The predetermined return timing is a timing at which a predetermined time elapses after the slip speed Vs becomes equal to or higher than the torque output threshold Vs1, or a predetermined time after the execution of this routine is started (from when the ABS control is executed). It is also possible to use a timing at which elapses.

  Tm = ((Vs / Ts / (3.6 ・ Rt) -μ ・ Mg ・ Rt / Ib) ・ It-μ ・ mg ・ Rt + Fb ・ Rt) / G (1)

  Subsequently, the load factor R to be multiplied by the basic torque Tbase is set based on the slip speed Vs (step S200), and the product of the basic torque Tbase and the load factor R is set to the torque command Tm2 * to be output from the motor MG2. (Step S210), the set torque command Tm2 * is transmitted to the motor ECU 40 (Step S230), and this routine ends. Receiving the torque command Tm2 *, the motor ECU 40 performs switching control of the inverter 42 so that the motor MG2 is driven by the torque command Tm2 *. Here, in the embodiment, the load factor R is a value corresponding to the slip velocity Vs, and an annealing slip velocity Vss obtained by subjecting the slip velocity Vs to the annealing treatment is obtained, and the slip velocity Vs and the load factor R are obtained. When the smoothing slip speed Vss is given to the load factor setting map stored in the ROM 74 in advance, the corresponding load factor R is derived from the stored map. The reason why the smoothing process is performed on the slip speed Vs is to suppress the load factor R from vibrating due to the vibrating slip speed Vs. FIG. 4 shows an example of the load factor setting map. As shown in the figure, as a value determined in advance by experiment or analysis in order to suppress the drive wheel speed Vd from exceeding the estimated vehicle speed Vb, a value smaller than the torque output threshold Vs1 and larger than the torque output stop threshold Vs2 is determined. The load factor R is set to a value 1 in the range where the slip speed Vs is equal to or higher than the torque reduction threshold Vs3 with the torque reduction threshold Vs3 as a boundary, and in the range where the slip speed Vs is less than the torque reduction threshold Vs3, The load factor R is determined to decrease to 0 as the value decreases to 0. The torque reduction threshold value Vs3 may be a value equal to the torque output threshold value Vs1. Further, considering that the load factor R is less than 1 only when the slip speed Vs becomes small and the vibration of the torque from the motor MG2 is limited, the smoothed slip speed Vss is set when the load factor R is set. The slip speed Vs may be used as it is without using.

  When the positive torque output flag F is 0 in step S180, the regenerative torque (corresponding to the share of the motor MG2 among the share of the hydraulic brake based on the brake pedal depression amount and the vehicle speed V and the share of the motor MG2) Torque obtained by limiting the negative torque) with a predetermined lower limit (negative value) is set as a torque command Tm2 * of the motor MG2 (step S220), and the set torque command Tm2 * is transmitted to the motor ECU 40 ( Step S230), this routine is finished.

  FIG. 5 shows an example of temporal changes in estimated vehicle body speed Vb, driving wheel speed Vd, positive torque output flag F, slip speed Vs, maximum slip speed Vsmax, load factor R, and motor torque Tm2 during ABS operation. It is explanatory drawing. In the figure, the load factor R is illustrated as being calculated regardless of the execution of the routine of FIG. As shown in the figure, when the ABS control is executed by depressing the brake pedal on a low μ road with a small friction coefficient (time t1) and the driving wheel speed Vd is greatly reduced (rapidly reduced), the rotation of the motor MG2 is caused by inertia. Since it is predicted that the twisting of the shaft between the axle and the drive shaft 32 is promoted when the drive wheel speed Vd starts to increase due to the decrease in speed, the possibility that the drive wheel speed Vd vibrates is determined. When this occurs (time t2), the maximum slip speed Vsmax becomes the maximum value during this control as the slip speed Vs increases (time t3). In the embodiment, the basic torque Tbase is determined based on the maximum slip speed Vsmax so that the driving wheel speed Vd coincides with the estimated vehicle speed Vb within a predetermined time from the time t3. When the slip speed Vs decreases and becomes less than the torque reduction threshold Vs3 (specifically, when the smoothed slip speed Vss becomes less than the torque reduction threshold Vs3) (time t4), the load factor R becomes smaller than the value 1. When the slip speed Vs becomes less than the torque output stop threshold Vs2 (time t5), the output of the driving side (positive side) torque from the motor MG2 is stopped. Note that the vehicle stops depending on the subsequent brake operation.

  In this way, a torque corresponding to the basic torque Tbase corresponding to the maximum slip speed Vsmax, which is the maximum value after the ABS control is executed as the torque for making the driving wheel speed Vd coincide with the estimated vehicle body speed Vb, is set to the motor MG2. Since the maximum slip speed Vsmax that is output from the vehicle, i.e., does not vibrate, is used, torque corresponding to the slipping speed Vs that is oscillating as torque for matching the driving wheel speed Vd to the estimated vehicle speed Vb is output from the motor MG2. In contrast, the vibration (amplitude) of the driving wheel speed Vd can be prevented from being promoted by the torque from the motor MG2. Further, by matching the driving wheel speed Vd with the estimated vehicle body speed Vb, the driving wheels 63a and 63b can be brought into the grip state by a force based on the static friction coefficient instead of the dynamic friction coefficient between the wheels and the road surface. The vibration of the driving wheel speed Vd can be suppressed. As a result, it is possible to suppress inconveniences such as an increase in the braking distance by reducing the hydraulic pressure of the hydraulic brakes of the driving wheels 63a and 63b by the ABS control due to the vibration of the driving wheel speed Vd during the execution of the ABS control. As a result, it is possible to more appropriately suppress the vibration of the drive wheel speed Vd when the ABS control is executed. In addition, since the motor MG2 outputs a torque corresponding to the basic torque Tbase for making the driving wheel speed Vd coincide with the estimated vehicle speed Vb at a predetermined return timing, the timing when the driving wheel speed Vd coincides with the estimated vehicle speed Vb. It is possible to prevent the behavior of the vehicle from being different due to the difference (for example, a feeling of popping out). Further, when the slip speed Vs is less than the torque reduction threshold Vs3, a torque obtained by multiplying the basic torque Tbase by a load factor R that becomes smaller than the value 1 as the slip speed Vs becomes smaller is output from the motor MG2. By outputting a torque corresponding to the basic torque Tbase from the motor MG2 in a reduced state, it is possible to suppress the drive wheel speed Vd from exceeding the estimated vehicle body speed Vb (overshoot), and the drive wheels 63a and 63b. Can be more reliably brought into a grip state.

  According to the hybrid vehicle 20 of the embodiment described above, the ABS control by the brake ECU 94 that prevents slip due to wheel locking based on the brake operation during traveling is executed, and the driving wheel speed Vd is subtracted from the estimated vehicle body speed Vb. When the obtained slip speed Vs becomes equal to or higher than the torque output threshold Vs1, the maximum value of the slip speed Vs after the ABS control is executed as the torque for making the driving wheel speed Vd coincide with the estimated vehicle speed Vb. The basic torque Tbase is set so as to increase as the maximum slip speed Vsmax increases, and the torque corresponding to the basic torque Tbase is output from the motor MG2. Therefore, the torque based on the oscillating slip speed Vs is output from the motor MG2. Compared with the maximum slip speed Vsmax that does not vibrate. Can output torque from the motor MG2, it is possible to more properly suppress the vibration of the driving wheel speed Vd when the ABS control by the brake ECU94 has been executed.

  In the hybrid vehicle 20 of the embodiment, the basic torque Tbase is determined so that the driving wheel speed Vd matches the estimated vehicle speed Vb at a predetermined return timing, but in order to make the driving wheel speed Vd match the estimated vehicle speed Vb. The basic torque Tbase may be determined so that the driving wheel speed Vd matches the estimated vehicle body speed Vb before and after a predetermined return timing.

  In the hybrid vehicle 20 of the embodiment, the basic torque Tbase is multiplied by the load factor R to set the torque command Tm2 * of the motor MG2. However, without setting the load factor R, the basic torque Tbase is directly applied to the motor MG2. The torque command Tm2 * may be set.

  In the hybrid vehicle 20 of the embodiment, the torque output stop threshold Vs2 is a value smaller than the torque output threshold Vs1, but the torque output stop threshold Vs2 may be the same value as the torque output threshold Vs1.

  In the hybrid vehicle 20 of the embodiment, the motor MG2 is controlled using the slip speed Vs obtained by subtracting the drive wheel speed Vd from the estimated vehicle speed Vb, but the slip speed Vs is used instead of the slip speed Vs. The motor MG2 may be controlled using a slip ratio (Vs / Vb) obtained by dividing by the estimated vehicle speed Vb.

  In the hybrid vehicle 20 of the embodiment, the description is applied to the case where both the drive wheels 63a and 63b slip simultaneously, but the present invention may be applied to the case where either one of the drive wheels 63a and 63b slips.

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the drive shaft 32 connected to the drive wheels 63a and 63b via the planetary gear 30, and the power from the motor MG2 is output to the drive shaft 32. However, as illustrated in the hybrid vehicle 120 of the modified example of FIG. 6, the motor MG is attached to the drive shaft 32 connected to the drive wheels 63 a and 63 b via the transmission 130, and the clutch 129 is attached to the rotation shaft of the motor MG. The engine 22 is connected to the motor 22 through the rotation shaft of the motor MG and the transmission 130 to the drive shaft 32 and the power from the motor MG is driven through the transmission 130 to the drive shaft. It is good also as what outputs to 32. Alternatively, as illustrated in the electric vehicle 220 of the modified example of FIG. 7, the power from the motor MG is output to the drive shaft 32 connected to the drive wheels 63 a and 63 b via the transmission 230 without providing an engine. It may be a thing. That is, any type of vehicle may be used as long as the vehicle includes a traveling motor, a battery, and a brake device capable of executing ABS control.

  In the embodiment, the present invention has been described as a form of the hybrid vehicle 20, but may be a form of a vehicle (for example, a train) other than the car.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the motor MG2 corresponds to the “motor”, the battery 50 corresponds to the “battery”, and the combination of the brake master cylinder 90, the brake actuator 92, and the brake wheel cylinders 96a to 96d corresponds to the “brake device”. The brake ECU 94 capable of executing ABS control corresponds to “brake control means”, and when the ABS control is executed and the slip speed Vs becomes equal to or higher than the torque output threshold Vs1, the driving wheel speed Vd is set to the estimated vehicle speed Vb. Motor control at the time of ABS operation of FIG. 2 in which the basic torque Tbase is set so as to increase as the maximum slip speed Vsmax increases as the torque for matching, and the torque based on the basic torque Tbase is set as the torque command Tm2 * of the motor MG2. HVECU 70 for executing the routine; The combination of a motor ECU40 for controlling the motor MG2 with the torque command Tm2 * corresponds to the "motor control means".

  Here, the “motor” is not limited to the motor MG2 configured as a synchronous generator motor, and may be any one that can input and output power to a drive shaft connected to a drive wheel, such as an induction motor. It may be of type. The “battery” is not limited to the battery 50 configured as a lithium ion secondary battery, but can exchange power with the motor, such as a nickel hydride secondary battery, a nickel cadmium secondary battery, and a lead storage battery. Any type can be used. The “brake device” is not limited to the combination of the brake master cylinder 90, the brake actuator 92, and the brake wheel cylinders 96a to 96d, and applies a braking force to the vehicle in accordance with or regardless of the brake operation. Any device can be used as long as it is possible. The “brake control means” is not limited to the brake ECU 94, and any brake control unit that executes the lock suppression control of the brake device that suppresses the slip due to the locking of the wheel based on the brake operation during traveling can be used. It doesn't matter. The “motor control means” is not limited to the combination of the HVECU 70 and the motor ECU 40, and may be configured by a single electronic control unit. Further, as the “motor control means”, the maximum slip speed is set as a torque for making the driving wheel speed Vd coincide with the estimated vehicle speed Vb when the ABS control is executed and the slip speed Vs becomes equal to or higher than the torque output threshold Vs1. The basic torque Tbase is set so as to increase as Vsmax increases, and the torque based on the basic torque Tbase is not limited to output from the motor MG2. After the lock suppression control is executed as the torque for matching the speed of the drive wheels to the vehicle body speed when the slip amount reflecting the speed difference obtained by reducing the speed of the vehicle is equal to or greater than a predetermined torque output threshold. The return torque is set so that it increases as the maximum slip amount, which is the maximum slip amount, increases. And one, but may be any so long as returning torque is set to control the motor so as to be output from the motor.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the vehicle manufacturing industry.

  20, 120 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 30 planetary gear, 32 drive shaft, 40 motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 Rotation position detection sensor, 50 battery, 52 battery electronic control unit (battery ECU), 62 differential gear, 63a, 63b driving wheel, 64a, 64b driven wheel, 70 hybrid electronic control unit (HVECU), 72 CPU, 74 ROM 76 RAM, 80 Ignition switch, 82 Shift position sensor, 84 Accelerator pedal position sensor, 86 Brake pedal position sensor, 88 Vehicle speed sensor, 90 Brake master system , 92 brake actuator, 94 brake electronic control unit (brake ECU), 96a to 96d brake wheel cylinder, 98a to 98d wheel speed sensor, 129 clutch, 130, 230 transmission, 220 electric vehicle, MG, MG1, MG2 motor .

Claims (4)

A motor capable of inputting / outputting power to / from a drive shaft connected to a drive wheel, a battery capable of exchanging electric power with the motor, and a brake capable of applying braking force to the vehicle according to or regardless of the brake operation A vehicle, and a brake control unit that executes lock suppression control of the brake device that suppresses slippage due to locking of a wheel based on a brake operation during traveling,
When the lock suppression control is executed and the slip amount reflecting the speed difference obtained by subtracting the speed of the drive wheel from the vehicle speed becomes equal to or greater than a predetermined torque output threshold, the speed of the drive wheel is set to the vehicle speed. As the torque for matching, the return torque is set so as to increase as the maximum slip amount, which is the maximum value of the slip amount after the lock suppression control is executed, increases, and the set return torque is set. Motor control means for controlling the motor so that is output from the motor;
A vehicle comprising: The vehicle according to claim 1,
The return torque is a torque for making the speed of the driving wheel coincide with the vehicle body speed at a predetermined return timing.
vehicle. The vehicle according to claim 1 or 2,
The motor control means is configured such that the slip amount is small when the lock amount is less than a predetermined torque reduction threshold after the slip suppression amount is greater than or equal to the torque output threshold value when the lock suppression control is executed. Means for controlling the motor such that a torque obtained by multiplying the return torque by a coefficient smaller than 1 is output from the motor;
vehicle. A vehicle according to any one of claims 1 to 3,
The motor control means, when the lock suppression control is executed and after the slip amount becomes equal to or greater than the torque output threshold, when the slip amount becomes less than the torque output stop threshold smaller than the torque output threshold, Means for controlling the motor such that output of the return torque from the motor is stopped;
vehicle.

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