JP2014201123A - Vehicular braking control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular braking control device capable of accurately notifying an operator of a fact of anti-economical state.SOLUTION: A vehicular braking control device includes: calculation means for calculating a determination target value for actual braking force on the basis of required braking force in accordance with a brake pedal stepping-on amount; threshold setup means for setting a determination threshold for baking force, the threshold for determining whether a drive operation of a vehicle including a braking operation is in an economical state; notification means for determining whether the determination target value is larger than the determination threshold, and notifying of a fact that the drive operation of the vehicle including the braking operation is not in an economical state, if the determination target value is larger than the determination threshold; detection means for detecting an action of braking control for suppressing an under-steering tendency or over-steering tendency of the vehicle; and switchover means for increasing the determination threshold of the threshold setup means, decreasing the determination target value of the calculation means, or decreasing a notification value of the notification means.

Description

  The present invention relates to a vehicle braking control device.

  In order to solve the problem of air pollution caused by exhaust gas and the price of petrochemical fuel, so-called eco-cars such as electric vehicles using electric motors as driving sources and hybrid vehicles using electric motors and internal combustion engines as driving sources are increasing. ing. Hereinafter, the term “eco” in the present specification is used as a term including both the meanings of such ecology (environment) and economy (price), and the term “eco state” is advantageous in terms of environment or price. A state that is disadvantageous in terms of environment or price is referred to as a “non-eco state”.

  In this type of eco-car, a hybrid vehicle notification system described in Patent Document 1 is known as a device that teaches an appropriate operation for improving a driver's driving skill and improving fuel efficiency. In this system, the current brake depression amount detected by the brake sensor, that is, the braking force of the vehicle according to the brake command value is calculated separately for the regenerative braking by the motor and the friction braking by the mechanical brake. The braking force of the vehicle calculated by dividing into minutes and friction braking is displayed as it is on the display device. As a result, the driver feels that the amount of friction braking by the mechanical brake is “loss”, that is, the current driving state is “non-eco”.

JP 2010-285091 A

  However, in the above-described conventional technology, the braking force calculated by dividing into regenerative braking and friction braking is displayed as it is, and therefore, understeer suppression control and oversteer suppression control for improving running stability are executed and When the braking ratio increases, there is a problem that a display indicating that the vehicle is in the non-eco state is displayed even though the brake operation amount does not change.

  The problem to be solved by the present invention is to provide a vehicular braking control device capable of accurately executing a notification to the operator that the vehicle is in a non-eco state.

  In the present invention, when the operation of the braking control that suppresses the understeer tendency or the oversteer tendency is detected, the determination threshold value is increased, the determination target value is decreased, or the notification amount indicating that the vehicle is in the non-eco state is decreased. This solves the above problem.

  According to the present invention, when the operation of the braking control for suppressing the understeer tendency or the oversteer tendency is detected, the determination threshold value is increased or the determination target value is decreased. There is no false notification that the vehicle is in the eco state. Or, when the operation of braking control that suppresses the understeer tendency or oversteer tendency is detected, the notification amount indicating that it is in the non-eco state is reduced, so that it can be distinguished from the normal non-eco state, and the driver feels uncomfortable Can be suppressed or alleviated.

1 is a block diagram showing a vehicle to which a vehicle brake control device according to an embodiment of the present invention is applied. It is a graph which shows an example of the relationship between the regenerative braking force and the friction braking force with respect to the vehicle speed in an electric vehicle. It is a graph for demonstrating the energy loss when a vehicle brakes. It is a control map which shows the relationship of the regenerative braking torque limit value of the electric motor with respect to the vehicle speed used by step S7 of FIG. 6A. It is a graph which shows the 1st example of control of regenerative braking power and friction braking power with respect to a driver's demand braking power. It is a graph which shows the 2nd example of control of regenerative braking power and friction braking power to a driver's demand braking power. It is a graph which shows the 3rd example of control of regenerative braking power and friction braking power to driver's demand braking power. It is a flowchart (the 1) which shows the control procedure of the brake control apparatus for vehicles which concerns on one embodiment of this invention. It is a flowchart (the 2) which shows the control procedure of the brake control apparatus for vehicles which concerns on one embodiment of this invention. It is a flowchart (the 3) which shows the control procedure of the brake control apparatus for vehicles which concerns on one embodiment of this invention. It is a flowchart (the 4) which shows the control procedure of the brake control apparatus for vehicles which concerns on one embodiment of this invention. It is a flowchart (the 5) which shows the control procedure of the brake control apparatus for vehicles which concerns on one embodiment of this invention. It is a flowchart (the 6) which shows the control procedure of the brake control apparatus for vehicles which concerns on one embodiment of this invention. It is a control block diagram which shows the example of control of the brake control apparatus for vehicles which concerns on one embodiment of this invention. It is a control block diagram which shows the example of control of the brake control apparatus for vehicles which concerns on other embodiment of this invention. It is a graph for demonstrating the effect by the example of control of FIG. It is a graph for demonstrating the effect by the example of control of FIG. It is a figure which shows an example of the vibration torque which vibrates the brake pedal as an alerting | reporting means. It is a figure which shows the result of adding the vibration torque added to the basic value of the friction braking torque.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, in this embodiment, a driving operation including a braking operation is in an eco state (hereinafter also referred to as an eco driving) or a non-eco state. Explain the idea.

If the vehicle weight M is stopped stepping on the brake pedal during running at vehicle speed V, the according to the energy conservation law, irrespective of the deceleration of the vehicle, kinetic energy MV ^2/2 = braking energy ∫Fdr is established. In the case of a vehicle using an electric motor as a travel drive source as in this example, among the above braking energy, the regenerative energy due to the regenerative braking of the motor is recovered by the battery (secondary battery), but the braking energy due to the friction brake is not frictional. Dissipates as heat and cannot be recovered. Therefore, the state where the regenerative braking of the electric motor is used as much as possible and the insufficient braking force is compensated by the friction brake can be said to be the eco state. For this reason, when the brake operation using the friction brake is executed even though the regenerative control of the electric motor is possible, it is evaluated that the state is not the eco state, that is, the non-eco state, and a notification to that effect is given.

  FIG. 2 is a graph showing an example of the relationship between the vehicle speed immediately before braking, the regenerative braking force and the friction braking force with respect to the vehicle speed, and the maximum value of the regenerative braking force of the motor in a vehicle equipped with an electric motor having a regenerative braking function. Shown in bold solid line. If the required braking force (vertical axis) by the driver's braking operation is less than the maximum value of the regenerative braking force, the vehicle can be decelerated only by the regenerative braking force and there is no energy loss due to friction braking. I can say that. On the other hand, if the required braking force by the driver's braking operation is in the region above the thick solid line, the regenerative braking force alone cannot satisfy the required braking force, and it is necessary to operate the friction brake. For this reason, since energy loss due to friction braking occurs, it is evaluated as a non-eco state.

  However, the evaluation as to whether or not the “non-eco state” of the present invention is true does not mean all cases in which energy loss due to friction braking occurs in a strict sense. That is, in addition to evaluating the eco state and the non-eco state with the maximum regenerative braking force curve shown in the figure as a boundary line, for example, up to + 10% of the maximum value of the regenerative braking force shown in the figure It may be evaluated as an eco state, or conversely, for example, up to -10% of the maximum value of the regenerative braking force may be evaluated as a non-eco state, and the value of such a boundary region can be set as appropriate. .

  The driver can learn ecological driving by notifying that the vehicle is in the non-eco state. For example, as shown in the left diagram of FIG. 3, in a situation where the target stop position is at a relatively far distance L1, as shown in the left diagram, the brake starts to be applied considerably before the target stop position, and the speed decreases at a long braking distance L1. FIG. 2 shows a comparison between the case where the braking operation is performed and the case where the braking is started near the target stop position and the braking operation is performed at a short braking distance L2 (<L1) as shown in the right figure. As described above, when there is a required braking force exceeding the maximum value of the regenerative braking force by the electric motor, energy loss due to the friction brake occurs.

  Therefore, aside from emergency situations such as sudden braking, even when the braking operation at a reduced speed is possible with a long braking distance L1 as shown in the left figure, the braking operation at a high deceleration speed was performed as shown in the right figure. If this is the case, the driver is informed that it is in the non-eco state. By doing this, the driver can recognize and learn that his braking operation is not eco-friendly, such as when the brake application timing is late or the brake pedal has been depressed more than necessary. As a result of trying to perform the braking operation as shown in the left figure, the cruising distance can be extended by increasing the power recovery amount.

  However, even if the driver's driving skill is improved to teach eco-driving, the driver is informed that the vehicle is actually eco-friendly but is not eco-friendly, or conversely, the vehicle is actually eco-friendly even though it is non-eco-friendly. Is not preferable because the driver performs erroneous recognition and learning. Therefore, in the present embodiment, various configurations described below are employed in order to improve the accuracy of notifying that the state is the eco state and the non-eco state.

  FIG. 1 is a block diagram showing a main part of an electric vehicle according to an embodiment to which a vehicle braking control device according to the present invention is applied. The vehicle braking control device of the present invention can be applied to all vehicles including a secondary battery that stores an electric motor as a driving source and stores regenerative power of the electric motor. Further, the present invention can also be applied to a hybrid vehicle including a secondary battery that uses an internal combustion engine and an electric motor as a driving source and stores regenerative electric power of the electric motor. In that sense, another example applied to the hybrid vehicle in part of the control will also be described.

  The vehicle of this example functions as a driving drive source for the vehicle, and has an electric motor (motor / generator) 11 having a function of regenerating traveling energy into electric energy, and electric power supplied to the electric motor 11 and regenerated by the electric motor 11. A high-power battery 12 composed of a secondary battery that stores power, an inverter 13 that converts and controls the power of the high-power battery 12 to be supplied to the motor 11, and converts and controls regenerative power of the motor 11 to the high-power battery 12; 13, a motor control unit 14 (hereinafter also referred to as MCU 14), a battery temperature sensor 15 that detects the temperature of the high-power battery 12 and outputs it to the MCU 14, and a charge state SOC (State Of Charge) of the high-power battery 12 A current sensor and a voltage sensor (not shown) for detecting .

  The MCU 14 monitors the charge / discharge state and the deterioration state of the high-power battery 12 and integrates the amount of charge / discharge detected by the current sensor, or calculates the charge state SOC based on the voltage value detected by the voltage sensor. And output to the VCU 50 upon request. In the case of the high-power battery 12 made of a lithium ion battery, the upper limit of the SOC value that can be charged and the lower limit of the SOC value that can be discharged are determined in order to prevent overcharge and overdischarge. If the value exceeds the upper limit of the SOC value, the charging is restricted. If the value is less than the lower limit, the discharge is restricted. In particular, in this example, the VCU 50 reads the state of charge SOC of the high-power battery 12 from the MCU 14, and restricts regenerative braking by the motor 11 in the braking control when the SOC value is at the upper limit (that is, full charge state). The required braking is mainly performed by friction braking. The non-eco notification at this time will be described later.

  In addition, when the battery temperature detected by the battery temperature sensor 15 is lower than a predetermined value, the MCU 14 limits charging because the internal resistance of the battery becomes high and causes battery deterioration. In particular, in this example, the VCU 50 reads the battery temperature of the high-power battery 12 from the MCU 14, and when the battery temperature is lower than a predetermined value and charging is restricted, regenerative braking by the motor 11 is performed in braking control. The driver's requested braking is limited to friction braking. The non-eco notification at this time will be described later.

  The battery temperature of the high-power battery 12 is based on the detected temperature from the temperature sensor provided in the high-power battery 12 and the input / output current values of the inside / outside air temperature sensor and the high-power battery 12 provided in the air conditioner. The temperature of the high-power battery 12 may be estimated in consideration of the temperature transfer coefficient and the conversion efficiency.

  Further, the vehicle of this example is provided as a hydraulic friction brake by hydraulic pressure or the like, and is provided on a brake pedal 21 operated by a driver and predetermined wheels 41 (in this example, all four wheels, front, rear, left, and right. The brake caliper 23 including the brake rotor 22 and the brake pad provided on only one wheel) and the hydraulic pressure is controlled according to the depression amount of the brake pedal 21, and the pressing force of the brake pad to the brake rotor 22 is applied. And a brake sensor that detects the amount of depression of the brake pedal 21 that the driver has depressed when decelerating and outputs this to a vehicle control unit 50 (hereinafter also referred to as VCU 50). 24.

  The hydraulic system is provided between the brake master cylinder 25 that operates according to the depression amount of the brake pedal 21, and between the brake master cylinder 25 and the brake caliper 23, and brake fluid piping into which brake fluid such as brake oil is injected. 26, a reservoir tank 27 that stores brake fluid, an electric brake booster 28 that is provided between the brake pedal 21 and the brake master cylinder 25, and reduces the depression force of the brake pedal 21, and the operation of the electric brake booster 28 Are provided in a brake fluid pipe 26 between the brake master cylinder 25 and the brake caliper 23, and each brake caliper is used to control the stability of the vehicle behavior. VDC (Vehicle Dynamics) which controls the hydraulic pressure to 23 Control) includes an actuator 29 and a VDC control unit 30 (hereinafter also referred to as VDCCU 30) that controls the VDC actuator 29 according to the vehicle speed and driving operation.

  The VDCCU 30 detects a driver's driving operation and vehicle speed in order to stabilize vehicle behavior, and controls brake pressure and motor output. Therefore, it detects the understeer tendency or oversteer tendency of the vehicle, detects the steering angle of the steered wheels and the lateral acceleration of the vehicle (so-called lateral G), detects the sliding due to the braking operation on sudden braking or frozen road surface, etc. By controlling the brake pressure of each wheel. The understeer tendency refers to the chassis characteristic that causes the vehicle to go out of the curve road when the vehicle's centrifugal force exceeds the ground friction force of the front wheel when accelerating with a constant steering angle on a curve road. It is a turning tendency seen in cars. On the other hand, the oversteer tendency is a chassis characteristic in which when the vehicle accelerates with a constant rudder angle on a curved road, the vehicle's centrifugal force exceeds the ground frictional force of the rear wheels, causing the vehicle to enter the inside of the curved road. It is a good turning tendency seen in rear-wheel drive vehicles.

  In order to detect such behavior of the vehicle, the wheel speed sensor 31 that detects the rotational speed of the wheel, the yaw rate sensor 32 that detects the yaw rate of the vehicle, and the steering angle of the steered wheels (the front wheels in the vehicle of this example) A steering angle sensor 33 to detect and a lateral G sensor 34 to detect the lateral acceleration of the vehicle are provided, and detection signals detected by the wheel speed sensor 31, the yaw rate sensor 32, the steering angle sensor 33, and the lateral G sensor 34 are as follows. Sent to the VCU 50 where the understeer tendency or oversteer tendency of the vehicle is detected. Also, the VDCCU 30 detects an operation signal of an anti-lock brake system ABS for stabilizing the vehicle behavior by detecting a slippage caused by a sudden braking or a frozen road surface, and an operation signal of an electronically controlled braking force distribution system EBD added thereto. Send to.

  Further, in the vehicle of this example, the output shaft of the electric motor 11 is connected to the automatic transmission 42 and rotates to the drive shaft 44 of each drive wheel 41 via a differential gear 43 that absorbs the rotation difference generated between the left and right drive wheels 41. Output is transmitted. The automatic transmission 42 is controlled by a transmission control unit 45 (hereinafter also referred to as TACU 45), and the vehicle control unit 50 is connected via the transmission control unit 45 to a shift lever setting position or an upshift state. The shift state such as whether or not and other various control states are monitored. The transmission applied to the vehicle of the present embodiment can be a manual transmission in addition to the automatic transmission 42. However, even when the manual transmission is applied, the vehicle control unit 50 can control the transmission control. Through the unit 45, at least a shift state such as a shift lever setting position or an upshift state is monitored.

  In the vehicle of this example, an accelerator pedal sensor 16 that detects the amount of depression of the accelerator pedal and outputs it to the VCU 50, and a vehicle speed sensor 17 that detects the vehicle speed based on the rotational speed of the electric motor 11 and the gear position of the automatic transmission 45, . The amount of depression of the accelerator pedal is input to the VCU 50 as a driver request value.

  A vehicle control unit 50 (hereinafter also referred to as a VCU 50) that controls the entire vehicle reads the driver's requested driving force with the accelerator pedal sensor 16, detects the current vehicle speed with the vehicle speed sensor 17, and further charges the high-power battery. Various states including (SOC), battery temperature, and deterioration state are monitored via the MCU 14, and the amount of power that can be input and output is calculated according to these states. Then, the electric motor 11 is controlled by controlling the inverter 13 based on the calculated electric energy.

  Further, the VCU 50 reads the driver's required braking force by the brake pedal 21, considers the regenerative braking force by the electric motor 11, and transmits a braking force command value to be generated by the friction brakes 22 and 23 to the BCU 31. The VDC actuator 29 receives the braking force calculation command value to be generated by the friction brakes 22 and 23 calculated by the BCU 31, and applies a necessary hydraulic pressure to the friction brakes 22 and 23 accordingly.

  In the vehicle of this example, the braking force according to the depression amount of the brake pedal 21 can be controlled based on any of the three control examples shown in FIGS. 5A to 5C. FIGS. 5A to 5C are graphs showing examples of the distribution of braking force applied to the vehicle with respect to the elapsed time since the brake pedal 21 was depressed.

  In the first control example shown in FIG. 5A, when the motor 11 can regenerate the driver's required braking force Treq by the brake pedal 21, this is preferentially distributed, and the required braking force Treq is Only when the maximum regenerative braking force Trb_max by the electric motor 11 is exceeded, assist braking by the friction braking force of the friction brakes 22 and 23 is performed. The friction braking force Tfb in this case is a value obtained by subtracting the maximum regenerative braking force Trb_max from the electric motor 11 from the required braking force Treq, and the braking force command value is calculated by the VCU 50 and output to the BCU 31. According to this first control example, since the regenerative braking force by the electric motor 11 is preferentially applied, the power recovery rate to the high-power battery 12 becomes the highest.

  The second control example shown in FIG. 5B is the first control shown in FIG. 5A in that the driver's required braking force Treq by the brake pedal 21 is preferentially distributed when it can be regenerated by the motor 11. Although common to the control example, the friction braking force Tfb of the friction brakes 22 and 23 is also assisted from the time before reaching the maximum regenerative braking force Trb_max by the electric motor 11 at that time.

  In the third control example shown in FIG. 5C, the friction braking force Tfb by the friction brakes 22 and 23 is preferentially applied to the driver's requested braking force Treq by the brake pedal 21, and the friction braking force Tfb is predetermined. The required braking force Treq is achieved by distributing a ratio, for example, n% of braking force to the regenerative braking force Trb by the electric motor 11 and adding it to the friction braking force Tfb. According to the third control example, although the amount of power recovered by the electric motor 11 is smaller than that in the first control example, the friction braking force by the friction brakes 22 and 23 is mainly used, so that the braking behavior of the vehicle is reduced. There is an advantage of being closer to the driver's feeling of braking operation.

  As described above, in the vehicle of this example, the regenerative braking force Trb by the electric motor 11 and the friction braking force Tfb by the friction brakes 22 and 23 are applied according to the depression amount of the brake pedal 21 of the driver. The driver has a function of evaluating whether the depression operation of the brake pedal 21 is eco-friendly or non-eco-friendly. And when it is non-eco-driving, it notifies that to a driver. As this notification means, in addition to notification to the driver by vibration of the brake pedal 21 described later, notification to the driver by vibration of the steering wheel and seat, notification to the driver by sound and voice, display installed in the vehicle interior (for example, Various means using the driver's vision, hearing, touch, etc., such as notification to the driver by display on a navigation device or a display device of an instrument panel) are included.

  In this example, notification to the driver that the vehicle is not eco-friendly is performed by vibration of the brake pedal 21. That is, the VCU 50 outputs a signal for causing the brake pedal 21 to vibrate to the BCU 31 when the driver's braking operation is evaluated to be in the non-eco state according to the procedure described later, and the electric brake booster 28 Control fluid pressure. Details of this operation will be described later. The electric brake booster 28 controls the hydraulic pressure of the brake master cylinder 25 to vibrate the brake pedal 21. A dedicated vibration motor is attached to the brake pedal 21, and the brake motor 21 is vibrated using this vibration motor. May be.

  Next, the operation of this example will be described with reference to the flowcharts of FIGS. 6A to 6F and the control block diagrams of FIGS. Hereinafter, the braking force is also referred to as braking torque.

<< Judgment Target Value Ts and Judgment Threshold Tlim >>
In step S1 of FIG. 6A, the braking torque Treq requested by the driver is calculated. In this example, the brake pedal depression amount of the driver is detected by the brake sensor 24 provided on the pedal bracket of the brake pedal 21, and the hydraulic braking torque that can be generated in the stroke is calculated to obtain the driver's required braking torque Treq. . Note that when the driver is informed of the non-eco state by the vibration of the brake pedal 21 as in this example, this signal may vibrate. In this case, a low-pass filter whose cutoff frequency is lower than the vibration frequency may be added, or a sine vibration waveform for removing the vibration component may be added (see step S44 in FIG. 6F).

  In step S <b> 2, the regenerative braking torque Trb generated by the driver's braking request is received from the MCU 14 among the regenerative torques actually realized in the power running / regenerating motor 11 (motor / generator). The regenerative braking torque by the electric motor 11 includes the coasting brake torque in addition to the regenerative braking torque that collects electric power to the high-power battery 12 by simultaneously controlling the inverter 13 so that desired electric power is generated in the electric motor 11 and brakes the vehicle. There are regenerative braking torque.

  The coast regenerative braking torque is a braking torque that is transmitted as a rotational torque of the electric motor 11 after the accelerator is released, and becomes a rotational resistance of the electric motor 11 at this time, and is applied to an engine brake of the vehicle equipped with the internal combustion engine. The corresponding braking torque. The coast regenerative braking torque absorbs the kinetic energy of the vehicle and dissipates as heat generated by the motor 11 itself and frictional heat between the tire and the road surface. Therefore, the execution regenerative braking torque Trb in step S2 is equal to the actual regenerative braking torque by the electric motor 11 minus the coast regenerative braking torque. In the block diagram of FIG. 1, the MCU 14 calculates actual regenerative power supplied from the inverter 13 to the high-power battery 12 using a current sensor or voltage sensor, and executes regenerative braking torque based on this actual regenerative power. Trb is calculated and transmitted in response to a request from the VCU 50.

  In step S3, a difference braking torque Tdif = Treq−Trb between the required braking torque Treq input in steps S1 and S2 and the execution regenerative torque Trb is calculated. Usually, when this value is positive, it becomes a command value of the friction braking torque of the friction brakes 22, 23, and when it is negative, braking only by the regenerative braking torque of the motor 11 is executed.

  Subsequent to or in parallel with steps S1 to S3, in step S4, the actual braking fluid pressure P acting on the friction brakes 22, 23 is input. Since the actual braking fluid pressure P can be detected by a fluid pressure sensor provided in the master cylinder 25 or the VDC actuator 29, it is calculated by sharing the detection signal of the fluid pressure sensor. This value is appropriately used through a filter such as a low-pass filter. Note that when the driver is informed of the non-eco state by the vibration of the brake pedal 21 as in this example, this signal may vibrate. In this case, the hydraulic pressure may be estimated from the command value of the friction braking torque, or a sine vibration waveform for removing the vibration component may be applied during the vibration operation (see step S44 in FIG. 6F).

  In step S5, the actual value Tfb_p of the sum total of the friction braking torque generated at each drive wheel 41 is calculated from the braking hydraulic pressure P calculated in step S4. This is the same for both the four-wheel simultaneous control and the control for every two wheels (one axis), and is calculated as the total torque.

  Subsequent to or in parallel with steps S1 to S3 and steps S4 to S5, in step S6, the braking torque Treq requested by the driver is calculated in the same manner as in step S1. That is, in this example, the brake pedal operation of the driver is detected by the brake sensor 24 provided on the pedal bracket of the brake pedal 21, the hydraulic braking torque that can be generated in the stroke is calculated, and the driver's required braking torque Treq is calculated. To do. In the case of a routine in which steps S1 to S3 and steps S6 to S7 are arithmetically processed, the calculation result of step S1 may be used. Note that when the driver is informed of the non-eco state by the vibration of the brake pedal 21 as in this example, this signal may vibrate. In this case, a low-pass filter whose cutoff frequency is lower than the vibration frequency may be added, or a sine vibration waveform for removing the vibration component may be added (see step S44 in FIG. 6F).

  In step S7, the friction braking torque generated at each drive wheel 41 from the required braking torque Treq calculated in step S6, the vehicle speed V detected by the vehicle speed sensor 17, and the control map obtained in advance through experiments and simulation calculations. Is calculated as an estimated value Tfb_map. FIG. 4 shows an example of the control map. This control map is obtained by mapping the maximum regenerative torque in a state where various regenerative torque limitations shown in steps S10 to S38 described later are not activated according to the vehicle speed, the vehicle speed is V, and the required braking calculated in step S7. When the torque is Treq, a value obtained by subtracting the regenerative torque limit value shown by the solid line from the required braking torque Treq is obtained as the estimated value Tfb_map of the friction braking torque as shown in the figure.

  In step S8, the minimum value is selected from the differential braking torque Tdif obtained in step S3, the actual value Tfb_p of the total friction braking torque obtained in step S5, and the estimated value Tfb_map of the total friction braking torque obtained in step S7. Calculate and set this value as the select row Ts. This is the determination target value Ts for determining whether or not the current driving operation is in the non-eco state.

  In step S8, the minimum values of the differential braking torque Tdif, the actual value Tfb_p of the total friction braking torque, and the estimated value Tfb_map of the total friction braking torque are obtained, but steps S6 and S7 are omitted. In S8, the minimum value of the difference braking torque Tdif and the actual value Tfb_p of the total sum of the friction braking torques may be obtained, and this may be used as the select row Ts. Alternatively, steps S4 and S5 may be omitted, and the minimum value of the differential braking torque Tdif and the estimated value of the friction braking torque Tfb_map may be obtained in step S8, and this may be used as the select row Ts.

  In step S8, the minimum value of the differential braking torque Tdif, the actual value Tfb_p of the total friction braking torque, and the estimated value Tfb_map of the total friction braking torque is determined to determine whether or not the current driving operation is in the non-eco state. The target value Ts is selected, and it is determined whether or not it is larger than the determination threshold value Tlim in step S43, which will be described later. That is, if the minimum value Ts of the three target values Tdif, Tfb_p, and Tfb_map is larger than the determination threshold value Tlim, the other two target values are also larger than the determination threshold value Tlim. Get higher.

  In step S9, a determination threshold value Tlim for determining whether or not the select row Ts is in the non-eco state is calculated. The evaluation criterion for the non-eco state in this example is the friction braking torque in a state where the regenerative braking torque by the electric motor 11 at the vehicle speed V is maximum. For example, in the first control example shown in FIG. 5A and the second control example shown in FIG. 5B, the friction braking torque at the time t at which the regenerative braking force by the electric motor 11 becomes maximum is set as the determination threshold Tlim. Further, in the third control example shown in FIG. 5C, the friction braking torque at the time t at which the regenerative braking torque by the electric motor 11 is maximized is set as the determination threshold value Tlim.

  Note that the friction brakes 22 and 23 may be set in a state where the brake rotor 22 and the brake pad of the brake caliper 23 are separated from each other as necessary, or in a low drag state. In any case, the friction braking torque at the point where the friction braking force is actually generated is set as the determination threshold Tlim.

  The determination target value Ts and the determination threshold value Tlim are determined to have a magnitude relationship as shown in FIGS. 7 and 8 (see also step S43 in FIG. 6F), and as a general rule, Ts> Tlim is in a non-eco state. Is executed. In FIG. 7, the driver requested braking torque Treq and the effective regenerative braking torque Trb are input to the adder / subtractor, and the difference braking torque Tdif is calculated by the calculator. The difference braking torque Tdif and the actual value Tfb_p of the friction braking torque are the minimum. The value is input to the value calculator, and the minimum value is output as the determination target value Ts. On the other hand, the judgment threshold Tlim and the pseudo friction braking torque Tfb_map are input to the switch, and the output is switched by the regenerative braking limit flag. Then, the determination target value Ts that is the output of the minimum value calculator and the determination threshold value (or the pseudo friction braking torque that is overwritten on the determination threshold value) that is the output of the switching device are input to the comparator and are in the non-eco state. A notification to that effect is output.

  FIG. 8 is another example of the control example shown in FIG. 7. The driver requested braking torque Treq and the execution regenerative braking torque Trb are input to the adder / subtractor, and the difference braking torque Tdif is calculated by the calculator. Tdif and the actual value Tfb_p of the friction braking torque are input to the minimum value calculator, and the minimum value is output as the determination target value Ts. Further, the determination target value Ts and the pseudo friction braking torque Tfb_map are input to the switch, and the output is switched by the regenerative braking limit flag. Then, the determination threshold value Tlim and the determination target value (or the pseudo friction braking torque overwritten on the determination target value) that is the output of the switching device are input to the comparator, and a notification that the vehicle is in the non-eco state is output. .

The next steps S10 to S38 are steps for changing the non-eco state detection method.
《Vehicle speed》
In step S10 shown in FIG. 6B, the vehicle speed V is input using the vehicle speed sensor 17 or the like. In step S11, it is determined whether or not the vehicle speed V is less than the vehicle speed Valt that starts replacing the regenerative braking torque with the friction braking torque. When the current vehicle speed V is lower than the friction braking torque alternative start vehicle speed Valt, the process proceeds to S12, and the processing at the time of low-speed regeneration decrease in steps S12 to S14 is executed. If the current vehicle speed V is not lower than the friction braking torque alternative start vehicle speed Valt, these processes S12 to S14 are skipped and the process proceeds to S15.

  In step S12, the maximum value Trb_max of the regenerative braking torque when the vehicle speed V falls below the friction braking torque alternative start vehicle speed Valt is calculated and stored. This value may be set in advance based on FIG. In step S13, a value obtained by subtracting the maximum value Trb_max of the regenerative braking torque calculated in step S12 from the driver required braking force Treq is calculated as the second differential braking torque Tdif2. In step S14, the value of the select low value Ts is replaced with Tdif2.

  The processing in steps S12 to S14 corresponds to substituting the Trb_max value in place of the effective regenerative braking torque Trb in S1 to S3. That is, when the vehicle speed V is lower than the Valt, the regenerative braking force and the regenerative power by the electric motor 11 are reduced, and the time until the vehicle is stopped is short. Few. Therefore, the determination target value Ts that is in the non-eco state is replaced with the minimum value, so that the determination target value Ts (= Tdif2 ≦ Tdif) does not exceed the determination threshold value Tlim in step S38.

<< EBD / ABS >>
In step S15 shown in FIG. 6C, an ABS operation flag F_abs indicating whether or not the antilock brake system ABS and the electronically controlled braking force distribution device EBD are operating is input from the VDCCU 30. The ABS operation flag F_abs is set to 1 when the system is operating, and is set to 0 when the system is not operating. In step S16, it is determined whether the ABS operation flag F_abs input in step S15 is 0 or 1. If the ABS operation flag F_abs is 1 (operated), the process proceeds to step S49 to stop the vibration of the brake pedal 21. If the ABS operation flag F_abs is 0 (not operating), the process continues to the next step S17.

<< Understeer / Oversteer >>
In step S17, the suppression control intervention flag F_us at the time of an understeer tendency or an oversteer tendency is input from the VDCCU 30. An understeer suppression control intervention flag may be input when the vehicle is a front-wheel drive vehicle, and an oversteer suppression control intervention flag may be input when the vehicle is a rear-wheel drive vehicle. The US / OS suppression control intervention flag F_us is set to 1 in F_us when US / OS suppression control is executed. Further, when the execution is completed from the state where the US / OS suppression control flag is 1, 1 is continuously set to F_us during one braking, and 0 is set to F_us when one braking is completed.

  A switch such as a brake lamp switch or the stroke value of the brake pedal 21 may be used for the end of one braking. Further, in the regenerative cooperative system as in the first and second control examples shown in FIGS. 5A and 5B, it is determined that the braking is finished when the regenerative braking amount returns to the driver requested deceleration, and F_us is set to 0. You may reset it.

  In step S18, it is determined whether the US / OS suppression control flag F_us is 1 or 0. When the US / OS suppression control intervention flag F_us is 1 (intervening), the process proceeds to step S19. If the US / OS suppression control flag F_us is 0 (non-intervening), the gain g multiplied by the pedal vibration amplitude A is set to 1.0, and the process proceeds to step S20.

  In step S19, processing at the time of US / OS suppression control intervention is performed. In this process, first, the pseudo friction braking torque Tfb_map when the US / OS suppression control does not intervene is calculated from the driver required braking torque Treq and the vehicle speed V. This simulates a state in which the regenerative braking force is not reduced by the US / OS suppression control, and is calculated from the control map shown in FIG. This pseudo friction braking torque Tfb_map has a relationship of Tlim <Tfb_map during the US / OS suppression control.

  When the determination target value Ts in the non-eco state exceeds the determination threshold value Tlim, the gain g by which the pedal vibration amplitude A is multiplied is set to a value less than 1.0 (for example, 0.5). Further, the judgment target value Ts is compared with the pseudo friction braking torque Tfb_map. If the judgment target value Ts exceeds the pseudo friction braking torque Tfb_map, the gain g by which the pedal vibration amplitude A is multiplied is set to 1.0, and step S9. The pseudo friction braking torque Tfb_map is overwritten and set to the determination threshold value Tlim set in step (1).

  In this way, when the determination target value Ts is equal to or less than the pseudo friction braking torque Tfb_map, notification that the non-eco state is caused by pedal vibration is not made, and the determination target value Ts is determined from the determination threshold value Tlim to the pseudo friction braking torque. During Tfb_map, the gain g multiplied by the pedal vibration amplitude A is reduced to inform weakly that it is in the non-eco state, and when the judgment target value Ts exceeds the pseudo friction braking torque Tfb_map, the normal vibration strength It will be notified by the pedal vibration.

  This is shown in FIG. The left diagram of FIG. 9 shows a state without US / OS suppression control intervention, the central diagram of FIG. 9 shows the state of US / OS suppression control intervention, and the right diagram of FIG. 9 executes the processing of step S19 in this example. It is a graph of the braking torque with respect to time which shows each state. As shown in the left diagram of the figure, the regenerative braking torque when the intervention of the US / OS suppression control is performed as shown in the central diagram of the figure as compared to the judgment threshold Tlim when there is no intervention of the US / OS suppression control. Therefore, the friction braking torque Tfb increases to exceed the determination threshold value Tlim, and an erroneous notification that the driver is in the non-eco state despite the same braking operation is performed. However, as a result of executing the processing of step S19 as in this example, the determination threshold Tlim is replaced with the pseudo determination threshold Tfb_map, so that the notification is the same as when there is no US / OS suppression control intervention.

  In step S19, when the determination target value Ts in the non-eco state exceeds the determination threshold value Tlim as the determination process to the effect that the non-eco state occurs when the US / OS suppression control intervenes, the pedal vibration amplitude A is set. When the gain g to be multiplied is set to a value less than 1.0 (for example, 0.5), and when the determination target value Ts exceeds the pseudo friction braking torque Tfb_map, the gain g to be multiplied by the pedal vibration amplitude A is set. 1.0, and the pseudo friction braking torque Tfb_map is overwritten on the determination threshold value Tlim. However, only the former process or only the latter process may be performed. In this case, when only the latter process is performed, the gain multiplied by the pedal vibration amplitude A may be set to 0 (do not vibrate).

  In step S19, when the judgment target value Ts exceeds the pseudo friction braking torque Tfb_map, the gain g multiplied by the pedal vibration amplitude A is set to 1.0, and the pseudo friction braking torque Tfb_map is overwritten to the judgment threshold Tlim. Instead, the value of the determination threshold value Tlim may be left as it is, and the pseudo friction braking torque Tfb_map may be overwritten on the determination target value Ts.

《Vehicle turning behavior》
In the next step S20, the turning acceleration G of the vehicle is calculated based on detection signals from the vehicle speed sensor 17, the steering angle sensor 32, and the lateral G sensor 33. Even in a vehicle capable of regenerative braking by the electric motor 11, the stronger the turning state (steering angle, lateral G, yaw rate is larger) exceeding the normal range by the VCU 50 and VDCCU 30, the bias of the braking force due to only the regenerative braking force is Execute control to correct by using friction braking force together. In this example, when the absolute value of the turning acceleration G of the vehicle is larger than a preset turning threshold YGlim, the control for limiting the regenerative torque is executed by the VCU 50 and the VDCCU 30. The following processing is executed to increase the

  In step S21, it is determined whether or not the turning acceleration G of the vehicle exceeds a preset turning threshold YGlim. If the turning acceleration G of the vehicle exceeds the turning threshold YGlim, the process proceeds to step S22. When the turning acceleration G of the vehicle is less than the turning threshold YGlim, the gain g multiplied by the pedal vibration amplitude A is set to 1.0, and the process proceeds to step S23 shown in FIG. 6D.

  Note that this determination result is maintained when the turning acceleration G of the vehicle exceeds the turning threshold YGlim even once during one braking. When the braking is completed, the determination result is cleared. For the termination of the braking, a switch such as a brake lamp switch may be used, or the stroke value of the brake pedal 21 may be used. Further, in the regenerative cooperative system such as the first and second control examples shown in FIGS. 5A and 5B, it is determined that the braking is finished when the regenerative braking amount returns to the driver requested deceleration, and the turning acceleration G of the vehicle is determined. And the magnitude determination result of the turning threshold YGlim may be cleared again.

  In step S22, processing at the time of turning suppression control intervention when the vehicle turns significantly is performed. In this process, first, the pseudo friction braking torque Tfb_map when the turning suppression control is not intervening is calculated from the driver required braking force Treq and the vehicle speed V. This simulates a state in which the regenerative braking force is not reduced by the turning suppression control, and is calculated from the control map shown in FIG. The pseudo friction braking torque Tfb_map has a relationship of Ts> Tfb_map during the turning suppression control.

  When the determination target value Ts in the non-eco state exceeds the determination threshold value Tlim, the gain g by which the pedal vibration amplitude A is multiplied is set to a value less than 1.0 (for example, 0.5). Alternatively, the gain g may be set smaller as the turning acceleration G of the vehicle increases. Further, the determination target value Ts is compared with the pseudo friction braking torque Tfb_map. When the pseudo friction braking torque Tfb_map exceeds the determination threshold value Tlim, the gain g multiplied by the pedal vibration amplitude A is set to 1.0, and the determination target value is determined. The pseudo friction braking torque Tfb_map is overwritten and substituted for Ts.

  In this way, when the determination target value Ts is equal to or less than the pseudo friction braking torque Tfb_map, notification that the non-eco state is caused by pedal vibration is not made, and when the determination target value Ts exceeds the determination threshold Tlim, When the gain g multiplied by the pedal vibration amplitude A is reduced, the non-eco state is weakly notified, and when the pseudo friction braking torque Tfb_map exceeds the judgment threshold Tlim, the normal vibration strength of the pedal vibration is notified. To come.

  In step S22, when the turning suppression control intervenes, the pedal vibration amplitude A is multiplied when the non-eco state determination target value Ts exceeds the determination threshold value Tlim as the determination process that the non-eco state is present. When the gain g is set to a value less than 1.0 (for example, a fixed value such as 0.5 or a gain g corresponding to the turning acceleration G), and the pseudo friction braking torque Tfb_map exceeds the determination threshold value Tlim, Although the gain g multiplied by the vibration amplitude A is set to 1.0 and the pseudo friction braking torque Tfb_map is overwritten and substituted for the determination target value Ts, only the former process or only the latter process may be performed. In this case, when only the latter process is performed, the gain multiplied by the pedal vibration amplitude A may be set to 0 (do not vibrate).

  In step S22, if the pseudo friction braking torque Tfb_map exceeds the determination threshold value Tlim, the gain g multiplied by the pedal vibration amplitude A is set to 1.0, and the pseudo friction braking torque Tfb_map is overwritten and substituted into the determination target value Ts. Instead, the value of the determination target value Ts may be left as it is, and the pseudo friction braking torque Tfb_map may be overwritten on the determination threshold value Tlim.

"Sudden braking"
In step S23 shown in FIG. 6D, the sudden braking determination flag F_sb based on the detection signal of the brake sensor 24 is input. Whether the braking is sudden or not is determined as sudden braking when the amount of depression of the brake pedal 21 per unit time exceeds a predetermined value or simply when the amount of depression of the brake pedal 21 exceeds a predetermined value. The determination flag F_sb = 1 is set. When it is determined that the braking is sudden even once during one braking, the determination result is kept, and when one braking is completed, the determination result is cleared, that is, the sudden braking determination flag F_sb = 0 is set. A switch such as a brake lamp switch or the stroke value of the brake pedal 21 may be used for the end of one braking. Further, in the regenerative cooperative system as in the first and second control examples shown in FIGS. 5A and 5B, it is determined that the braking is finished when the regenerative braking amount returns to the driver requested deceleration, and the sudden braking determination flag F_sb May be reset to 0.

  In step S24, it is determined whether the sudden braking determination flag F_sb is 1 or 0. When the sudden braking determination flag F_sb is 1, the process proceeds to step S25. If the sudden braking determination flag F_sb is 0, the gain g multiplied by the pedal vibration amplitude A is set to 1.0, and the process proceeds to step S26.

  In step S25, processing at the time of sudden braking determination is performed. In this process, when the determination target value Ts in the non-eco state exceeds the determination threshold value Tlim, the gain g multiplied by the pedal vibration amplitude A is set to a value less than 1.0 (for example, 0.5). In this way, when the determination target value Ts is equal to or smaller than the determination threshold value Tlim, notification that the non-eco state is caused by pedal vibration is not given, and when the determination target value Ts exceeds the determination threshold value Tlim, the pedal vibration amplitude By reducing the gain g multiplied by A, the fact that the vehicle is in the non-eco state is weakly notified. Note that instead of the processing in step 25, when the sudden braking determination flag F_sb is 1, the process proceeds to step S49, and notification that the vehicle is in the non-eco state may be prohibited.

《Transmission shift position》
In the next step S26, the shift position of the automatic transmission 42 is input from the TACU 45. In the vehicle of this example, the regenerative braking control by the electric motor 11 is executed only when the shift position of the automatic transmission 45 is set to the drive range (forward travel, D range), and other shift positions, that is, the neutral position, When the reverse range (reverse running), low range, or second range is set, regenerative braking control by the electric motor 11 is prohibited. For this reason, the information input in step S26 may be information that can determine whether or not the current shift position is at least the drive range. In addition, the drive range in this case includes those in the case where the transmission of the vehicle has settings such as a snow mode, a sports mode, and a brake mode.

  In step S27, it is determined whether or not the current shift position of the automatic transmission 45 is in a range where regenerative braking control by the electric motor 11 is possible, that is, a drive range. If the current shift position is in the drive range, the process proceeds to the next step S28. If the current shift position is not in the drive range, the process proceeds to step S49 in order to stop the notification of the non-eco state due to the vibration of the brake pedal 21. In the above-described transmission brake mode and the like, the friction brakes 22 and 23 may be set to operate even when the amount of depression of the brake pedal 21 is small. In such a mode, the brake pedal 21 is depressed. As soon as it is determined that it is non-eco, the brake pedal 21 may vibrate and feel annoying. If such a setting is made, the mode may be input in step S26 and removed in step S27.

<Battery temperature>
In the next step S28, the battery temperature TB of the high-power battery 12 is input from the battery temperature sensor 15. In this example, since the battery temperature sensor 15 is provided in the high-power battery 12, this detection signal is used. In view of this, the battery temperature of the high-power battery 12 may be estimated.

  In step S29, it is determined whether or not the battery temperature TB detected in step S28 exceeds the low temperature limit temperature TBlim. When the actual battery temperature TB exceeds the low temperature limit temperature TBlim, the process proceeds to the next step S31. On the other hand, if the actual battery temperature TB is equal to or lower than the low temperature limit temperature TBlim, it may be annoying because it is judged that it is non-eco-friendly by a small amount of brake operation, so the process proceeds to step S30. Change eco-judgment conditions. That is, as described above, when the battery temperature TB detected by the battery temperature sensor 15 is lower than the low-temperature limit temperature TBlim, the internal resistance of the high-power battery 12 increases and causes battery deterioration. Charging is limited. Therefore, the regenerative braking torque of the electric motor 11 is also limited with respect to the driver's required braking torque, and the friction braking torque by the friction brakes 22 and 23 is increased instead. Therefore, even if the braking operation of the same brake pedal 21 is performed, when the temperature of the high-power battery 12 is low, a notification that the vehicle is in the non-eco state may be issued.

  When the battery temperature detected by the battery temperature sensor 15 is equal to or lower than the low temperature limit temperature, this is maintained during one braking, and is reset when one braking is finished. A switch such as a brake lamp switch or the stroke value of the brake pedal 21 may be used for the end of one braking. Further, in the regenerative cooperative system such as the first and second control examples shown in FIGS. 5A and 5B, it may be determined that the braking is finished when the regenerative braking amount returns to the driver requested deceleration.

  In step S30, the process when the low temperature limit is imposed on the high-power battery 12 is executed. In this process, first, the pseudo friction braking torque Tfb_map when the low temperature restriction does not intervene is calculated from the driver required braking force Treq and the vehicle speed V. This simulates a state in which the regenerative braking force is not reduced due to the low temperature restriction, and is calculated from the control map shown in FIG. The pseudo friction braking torque Tfb_map has a relationship of Tfb_map <Ts when the low temperature is limited.

  When the determination target value Ts in the non-eco state exceeds the determination threshold value Tlim, the gain g by which the pedal vibration amplitude A is multiplied is set to a value less than 1.0 (for example, 0.5). Further, the determination threshold value Tlim is compared with the pseudo friction braking torque Tfb_map. When the pseudo friction braking torque Tfb_map exceeds the determination threshold value Tlim, the gain g multiplied by the pedal vibration amplitude A is set to 1.0, and the determination target value Ts. Is substituted for the pseudo friction braking torque Tfb_map.

  Thus, when the determination target value Ts is equal to or less than the determination threshold value Tlim, notification that the non-eco state is caused by pedal vibration is not performed, and the pseudo friction braking torque Tfb_map <the determination threshold value Tlim <the determination target value Ts. In such a case, a weak notification that the vehicle is in the non-eco state is made by reducing the gain g, and if the pseudo friction braking torque Tfb_map exceeds the determination threshold value Tlim, the pedal vibration of the normal strength is notified. become.

  In step S30, when the non-eco state determination target value Ts exceeds the determination threshold value Tlim, the gain g multiplied by the pedal vibration amplitude A is set to a value less than 1.0 (for example, 0.5), Further, the determination threshold value Tlim is compared with the pseudo friction braking torque Tfb_map. When the pseudo friction braking torque Tfb_map exceeds the determination threshold value Tlim, the gain g multiplied by the pedal vibration amplitude A is set to 1.0, and the determination target value Ts. Although the pseudo friction braking torque Tfb_map is overwritten and substituted into the above, only one of them may be executed.

  In step S30, the determination threshold Tlim is compared with the pseudo friction braking torque Tfb_map. If the pseudo friction braking torque Tfb_map exceeds the predetermined threshold Tm, the gain g is set to 0, and the determination target value Ts is set to the pseudo friction braking torque. A process for overwriting and substituting Tfb_map may be added. The predetermined threshold value Tm is a friction braking torque that is increased as a result of limiting the regenerative braking at a low temperature at which the traveling road surface is frozen. By doing so, when the pseudo friction braking torque Tfb_map exceeds a predetermined threshold value Tm, it is determined that the road surface is likely to be frozen, and notification that the vehicle is in the non-eco state is not performed. As a result, the driver can concentrate on driving operation.

  In step S30, if the pseudo friction braking torque Tfb_map exceeds the determination threshold value Tlim, the gain g multiplied by the pedal vibration amplitude A is set to 1.0, and the pseudo friction braking torque Tfb_map is overwritten and substituted into the determination target value Ts. Instead, the value of the determination target value Ts may be left as it is, and the pseudo friction braking torque Tfb_map may be overwritten on the determination threshold value Tlim.

《Battery SOC》
In step S31 illustrated in FIG. 6E, the SOC value of the high-power battery 12 is input from the MCU 14. In the vehicle of this example, when the state of charge (charge amount) of the high-power battery 12 exceeds a predetermined upper limit value Slim, the regeneration amount is limited to prevent overcharge. For this reason, the regenerative braking torque is also limited, and this is compensated by the friction braking torque.

  In step S32, it is determined whether or not the current SOC value of the high-power battery 12 exceeds the limit value Slim. The limit value Slim of the SOC value is a threshold (lower limit value) of the SOC region that limits regenerative braking by the electric motor 11 in order to limit the regenerative power to the high-power battery 12. For example, when limiting the regenerative braking by the electric motor 11 in the region where the SOC is 65% to 100%, the limit value is SOC = 65%. If the SOC value does not exceed the limit value Slim, the gain g multiplied by the pedal vibration amplitude A is set to 1.0, and the process proceeds to the next step S34. If the regenerative braking force is limited by the SOC value exceeding the limit value Slim, the non-eco-judgment is made by a small amount of brake operation, and braking is performed with an appropriate eco-operation amount. In order to perform erroneous notification that the state is the eco state, the process proceeds to S33, and the determination condition for the non-eco state is updated.

  In step S33, processing when the SOC value of the high-power battery 12 exceeds the limit value Slim and the regenerative braking force by the electric motor 11 is limited is executed. In this process, first, the pseudo friction braking torque Tfb_map when the regenerative braking force is not limited at high SOC is calculated from the driver's required braking torque Treq and the vehicle speed V. This simulates a state in which the regenerative braking force is not reduced due to the high SOC, and is calculated from the control map shown in FIG. At this time, the estimated value Tfb_map of the friction braking torque calculated in step S7 may be used as it is. The pseudo friction braking torque Tfb_map has a relationship of Tfb_map <Ts when the regenerative braking force at the time of high SOC is limited.

  When the relationship between the determination target value Ts in the non-eco state and the determination threshold value Tlim is Ts ≦ Tlim, the gain g multiplied by the pedal vibration amplitude A is set to 0, and the process proceeds to the next step S34. Further, when the relationship between the determination target value Ts in the non-eco state, the pseudo friction braking torque Tfb_map, and the determination threshold value Tlim is Ts> Tlim ≧ Tfb_map, the gain g multiplied by the pedal vibration amplitude A is a value less than 1.0 ( For example, it is set to 0.5). In this case, the gain g may be changed according to the magnitude of the SOC value. For example, the gain g = 0.5 may be set when SOC = 80%, and the gain g = 0 may be set when SOC ≧ 90%. Further, when the relationship between the pseudo friction braking torque Tfb_map and Tlim is Tfb_map> Tlim, the gain g multiplied by the pedal vibration amplitude A is overwritten and set to 1.0.

  In this way, when the determination target value Ts is equal to or less than the determination threshold value Tlim, notification of the non-eco state due to pedal vibration is not made, and even if the determination target value Ts is equal to or greater than the determination threshold value Tlim, pseudo friction braking is performed. When the torque Tfb_map is equal to or less than the determination threshold Tlim, the gain g to be multiplied by the pedal vibration amplitude A is decreased to inform weakly that the vehicle is in the non-eco state, and when the pseudo friction braking torque Tfb_map exceeds the determination threshold Tlim Will notify the pedal vibration with the usual strength.

  In step S33, if the relationship between the judgment target value Ts in the non-eco state, the pseudo friction braking torque Tfb_map, and the judgment threshold Tlim is Ts> Tlim ≧ Tfb_map, the gain g multiplied by the pedal vibration amplitude A is 1.0. If the relationship between the pseudo friction braking torque Tfb_map and Tlim is Tfb_map> Tlim, the gain g multiplied by the pedal vibration amplitude A is overwritten and set to 1.0. However, only one of them may be executed. When only the latter is executed, it is equivalent to overwriting the pseudo friction braking torque Tfb_map to the determination target value Ts selected in step S8.

  FIG. 10 shows how only the latter is executed. The left diagram of FIG. 10 shows a state where there is no restriction of regenerative braking due to high SOC, the center diagram of FIG. 10 shows the state where regenerative braking is restricted due to high SOC, and the right diagram of FIG. 10 shows the processing of step S33 of this example. It is a graph of the braking torque with respect to time which shows each state. As shown in the left figure of the figure, when the regenerative braking is restricted by the high SOC as shown in the central figure of the figure, the regenerative braking torque is compared with the judgment threshold value Tlim when there is no restriction of the regenerative braking by the high SOC. Therefore, the friction braking torque Tfb increases to exceed the determination threshold value Tlim, and an erroneous notification that the driver is in the non-eco state despite the same braking operation is performed. However, as a result of executing the process of step S33 as in this example, the determination target value Ts of the friction braking torque is replaced with the pseudo determination target value Tfb_map. As a result, the notification is the same as when there is no regenerative braking restriction due to high SOC. .

  In step S33, if the pseudo friction braking torque Tfb_map exceeds the determination threshold value Tlim, the gain g multiplied by the pedal vibration amplitude A is set to 1.0, and the pseudo friction braking torque Tfb_map is overwritten and substituted into the determination target value Ts. Instead, the value of the determination target value Ts may be left as it is, and the pseudo friction braking torque Tfb_map may be overwritten on the determination threshold value Tlim.

《HEV mode (only for hybrid vehicles)》
The next steps S34 and S35 are processing steps according to another example when the braking control device of this example is applied to a hybrid vehicle, and when the vehicle is an electric vehicle, these steps S34 and S35 are skipped. If the vehicle is a hybrid vehicle, an HEV mode switching flag F_hev is input in step S34. The HEV mode switching flag F_hev is an engine travel mode in which the hybrid vehicle travels using only the travel drive force of the internal combustion engine, and an engine / motor travel mode in which the hybrid vehicle travels using both the travel drive force of the internal combustion engine and the travel drive force of the motor. These are flag variables indicating state transitions between modes, such as an engine start mode for driving a motor to start an internal combustion engine and a motor EV travel mode for traveling only by the travel driving force of the motor. During and before and after switching between the modes, the required braking torque Treq due to depression of the brake pedal 21 may not be realized with the regenerative braking torque. When the hybrid vehicle is switching between modes, or before and after switching between the modes, the HEV mode switching flag F_hev = 1 is set. Otherwise, F_hev = 0 is set.

  For this reason, in step S35, it is determined whether or not the HEV mode switching flag F_hev indicating the transition state is 0. If it is determined that the mode is not being changed or not before (F_hev = 0), The process proceeds to step S36. On the other hand, if it is determined that the mode is being switched or before or after (F_hev = 1), the process proceeds to step S49 in order to stop the notification of the non-eco state due to the vibration of the brake pedal 21.

<< Transmission shift up >>
In the next step S36, an upshift flag F_up indicating whether or not the transmission is upshifting is input from the gear position information of the automatic transmission 45. When the transmission is upshifting, the regenerative braking torque Trb by the electric motor 11 is limited to perform a shift, and the flag F_up is set depending on whether or not the limitation is being executed. If upshifting is in progress, F_up = 1 is set, and even when the upshift is completed, the upshifting flag is continuously set to 1 during one braking, and the upshifting flag is set to 0 when braking is completed. Re-set. In addition, about completion | finish of braking, switches, such as a brake lamp switch, may be used, and the value of the stroke of the brake pedal 21 may be used. Further, in the regenerative coordination system as shown in FIGS. 5A and 5B, it may be determined that the braking is finished when the regenerative braking amount returns to the driver requested deceleration.

  In step S37, it is determined whether an upshift flag F_up is 0 or not. If the upshift flag F_up is 1, the process proceeds to step S38. If the upshift flag F_up is 0, the gain g multiplied by the pedal vibration amplitude A is set to 1.0, and the process proceeds to step S39.

  In step S38, processing during upshift is performed. In this process, first, the pseudo friction braking torque Tfb_map when the upshift is not performed is calculated from the driver required braking force Treq and the vehicle speed V. This simulates a state in which the regenerative braking force is not reduced by the upshift, and is calculated from the control map shown in FIG. The pseudo friction braking torque Tfb_map has a relationship of Ts> Tfb_map during upshifting.

  If the driver-requested braking torque Ts exceeds the determination threshold Tlim, the gain g multiplied by the pedal vibration amplitude A is set to a value less than 1.0 (for example, 0.5). Further, when shifting from the upshift state to the gear position holding state or the downshift state, the gain g is set to be larger than that during the upshift. Further, the determination target value Ts is compared with the pseudo friction braking torque Tfb_map. When the pseudo friction braking torque Tfb_map exceeds the determination threshold value Tlim, the gain g multiplied by the pedal vibration amplitude A is set to 1.0, and the determination target value is determined. The pseudo friction braking torque Tfb_map is overwritten on Ts.

  In this way, when the determination target value Ts is equal to or less than the determination threshold Tlim, notification that the non-eco state is caused by pedal vibration is not performed, and when the determination target value Ts exceeds the determination threshold Tlim, When the gain g multiplied by the pedal vibration amplitude A is reduced, the non-eco state is weakly notified. When the pseudo friction braking torque Tfb_map exceeds the determination threshold value Tlim, the pedal vibration is notified with the normal strength. Will do.

  In step S38, when the driver required braking torque Ts exceeds the determination threshold Tlim, the gain g multiplied by the pedal vibration amplitude A is set to a value less than 1.0 (for example, 0.5), and The judgment target value Ts is compared with the pseudo friction braking torque Tfb_map. If the pseudo friction braking torque Tfb_map exceeds the judgment threshold Tlim, the gain g multiplied by the pedal vibration amplitude A is set to 1.0, and the judgment target value Ts is set. Although the pseudo friction braking torque Tfb_map is overwritten, only one of them may be executed.

  In step S38, if the pseudo friction braking torque Tfb_map exceeds the determination threshold value Tlim, the gain g multiplied by the pedal vibration amplitude A is set to 1.0, and the pseudo friction braking torque Tfb_map is overwritten and substituted into the determination target value Ts. Instead, the value of the determination target value Ts may be left as it is, and the pseudo friction braking torque Tfb_map may be overwritten on the determination threshold value Tlim.

<Notice of non-eco status>
In steps S39 to S49 shown in FIG. 6F, the brake pedal 21 is vibrated to notify that the vehicle is in the non-eco state. Therefore, in step S39, the vibration amplitude A of the brake pedal 21 is set. Here, the gain g for the vibration amplitude A set in steps S10 to S38 described above is multiplied. By this process, the vibration level is changed according to the intervention of the suppression control for various regenerative braking shown in steps S10 to S38.

  In the next step S40, a vibration frequency f for vibrating the brake pedal 21 is set. In this example, in order to notify the driver that the brake pedal 21 has been depressed to the non-eco region, a level that can be recognized by the driver is set. At this time, the strength is set such that the driver feels that he / she does not want to further increase, but if necessary, it is set to a weakness that allows the driver to increase sufficiently smoothly and in a controllable manner.

  In step S41, the vibration amplitude A and the vibration frequency f are corrected so that the vehicle body vibration does not occur due to the fluid pressure fluctuation of the brake fluid generated by the vibration of the brake pedal 21. Specifically, if the hydraulic pressure vibration of the master cylinder 25 shown in FIG. 1 is oscillating at Asin2πf, this hydraulic pressure is attenuated by the pipe resistance and orifice effect of the brake fluid piping 26 and the VDC actuator 29, and driven. The fluid pressure fluctuation at the wheel 41 is | Asin2πf × VDC attenuation |. The magnitudes of the vibration amplitude A and the vibration frequency f are adjusted so that this magnitude is an allowable level for vehicle fluctuation, for example, 0.02 G or less for the vehicle G. In this example, the vibration amplitude A is mainly adjusted to be small.

  In step S42, the vibration frequency f is set so as to deviate from the resonance frequency Fd of the dash panel so that the dash panel of the vehicle does not resonate with the vibration of the brake pedal 21. Specifically, when the vibration frequency f is a constant multiple of the resonance frequency Fd of the dash panel, resonance with the surroundings of the dash panel can be prevented by setting the frequency to 1.1 times the frequency, for example. .

  In step S43, the determination target value Ts calculated in step S8 is compared with the determination threshold value Tlim calculated in step S9 and possibly updated in steps S10 to S38. If the determination target value Ts is equal to or greater than the determination threshold Tlim, it is determined that the vehicle is in the non-eco state, and the process proceeds to step S44. On the other hand, when the determination target value Ts is less than the determination threshold value Tlim, it is determined that the vehicle is not in the non-eco state (that is, the eco state), and the process proceeds to step S49.

  In step S49, it is determined whether the vibration is in one cycle based on the value of the vibration flag F_vibe. If the vibration flag F_vibe is ON (vibration is in the middle of one cycle), the process proceeds to step S44 in order to end the vibration after completing the vibration for one cycle. On the other hand, when the vibration flag F_vibe is OFF (vibration has ended for one cycle), steps S44 to S48 are skipped so as not to vibrate the brake pedal 21, and the process returns to step 1.

  In step S44, the above-described filtering process is performed, and in the next step S45, an additional vibration torque Tv to be added to the basic value of the friction braking torque is calculated. The additional vibration torque Tv may be set with a sine curve or may be set with a triangular wave. In this example, the additional vibration is set with a triangular wave as shown in FIG.

  In step S46, it is determined whether the vibration cycle has ended. This is a process for preventing the vibration from becoming discontinuous when the condition of step S43 (Ts ≧ Tlim) is not satisfied in the middle of the vibration cycle. When the vibration cycle is in the middle, the process proceeds to step S48, and the vibration flag F_vibe is set to ON. If the vibration cycle has ended, the process proceeds to step S47, and the vibration flag F_vibe is set to OFF.

  In step S50, the friction braking torque Tfb is set. When the vibration flag F_vibe is OFF, the friction braking torque Tfb is made to coincide with the differential braking torque Tdif calculated in step S3. This is based on the concept of regenerative cooperation in which the friction brake compensates for the amount of subtraction of the regenerative braking torque Trb that can be realized with the regenerative cooperative torque out of the braking force required by the driver. If the vibration flag F_vibe is ON, a calculation is performed as Tfb = Tdif + Tv as a value obtained by adding Tv calculated in step S45 to the differential braking torque Tdif that should be originally realized. Then, the electric control brake (electric brake booster 28) is driven so as to realize the calculated friction braking force. That is, the target hydraulic pressure of the brake master cylinder 25 is calculated. This is based on the calculated friction braking torque Tfb and constants such as the brake master cylinder diameter, the brake wheel cylinder diameter, the pad μ, and the brake rotor effective radius. It is converted using. The brake master cylinder pressure is controlled by driving the electric control brake (electric brake booster 28) based on the target brake master cylinder hydraulic pressure. When the vibration flag F_vibe is ON, the vibration component Tv is added, and the brake master cylinder hydraulic pressure vibrates at a certain period. In the electric control brake (electric brake booster 28), the brake master cylinder pressure is transmitted as a reaction force to the brake pedal 21 via the input rod. As a result, the fluctuation amount of the brake master cylinder hydraulic pressure is reduced by the brake pedal 21. The brake pedal 21 is vibrated as the reaction force fluctuation. The right diagram of FIG. 12 shows the result of adding the additional vibration torque Tv shown in the center diagram to the basic value of the friction braking torque shown in the left diagram.

<< Effects of Embodiment >>
As described above, according to the vehicle brake control device of the present example, the following operational effects can be obtained.
(1) In this example, as the determination target value Ts indicating whether or not to notify that the vehicle is in the non-eco state, as shown in steps S1 to S8 in FIG. 6A, at least the driver's required braking torque Treq and regenerative braking torque A difference braking torque Tdif from Trb, that is, a friction braking torque command value Tfb, or an actual friction braking torque value Tfp_p calculated from the brake fluid pressure, is selected to be smaller, and this smaller value is larger than the determination threshold Tlim. In such a case, a notification that the vehicle is in the non-eco state is given. Therefore, when Tdif ≧ Tfb (Ts = Tfb) and Ts (= Tfb) exceeds the determination threshold Tlim, Tdif ≧ Tfb> Tlim, and Tdif also exceeds the determination threshold Tlim. . Conversely, when Tfb ≧ Tdif (Ts = Tdif) and Ts (= Tdif) exceeds the determination threshold Tlim, Tfb ≧ Tdif> Tlim, and Tfb also exceeds the determination threshold Tlim. . As a result, false comparisons such as unnecessary display based only on the friction braking torque command value Tfb and continuation of display based only on the actual value Tfb_p of the friction braking torque by simply comparing one determination target value Ts with the determination threshold value Tlim. Is suppressed, and it is possible to accurately notify the operator that the vehicle is in the non-eco state. Such an effect is the same when the driver's required braking torque Treq and the estimated friction braking torque Tfb_map estimated from the control map in steps S6 to S7 in FIG.

(2) Further, in this example, as shown in steps S17 to S19 of FIG. 6C, when the operation of the braking control that suppresses the understeer tendency or the oversteer tendency is detected, the judgment set in step S9 to increase the judgment threshold value. The determination target value Ts set in step S8 to reduce the threshold value Tlim or the determination target value is replaced with the pseudo friction braking torque Tfb_map obtained from the driver required braking torque Treq and the vehicle speed V when the US / OS suppression control does not intervene. . As a result, even if the actual friction braking torque increases, if it is in the eco state until then, it is evaluated as the eco state, and no false notification of the non-eco state is made. In addition to or instead of this, when the operation of the braking control that suppresses the understeer tendency or the oversteer tendency is detected, the gain g multiplied by the vibration amplitude A of the brake pedal 21 is reduced to reduce the non-eco state. The amount of notification to the effect is reduced. As a result, the driver can be distinguished from the notification that the driver is in the normal non-eco state, and as a result, the uncomfortable feeling given to the driver can be suppressed or alleviated.

(3) Also, in this example, as shown in steps S20 to S22 of FIG. 6C, the determination threshold set in step S9 is set to increase the determination threshold when the braking control operation that suppresses the turning state of the vehicle is detected. The determination target value Ts set in step S8 to reduce Tlim or the determination target value is replaced with the pseudo friction braking torque Tfb_map obtained from the driver required braking torque Treq and the vehicle speed V when the control for suppressing the turning state does not intervene. As a result, even if the actual friction braking torque increases, if it is in the eco state until then, it is evaluated as the eco state, and no false notification of the non-eco state is made. In addition to this, or in place of this, when the operation of the braking control for suppressing the turning state of the vehicle is detected, the gain g multiplied by the vibration amplitude A of the brake pedal 21 is reduced, and the vehicle is in the non-eco state. Reduce the amount of notification to that effect. As a result, the driver can be distinguished from the notification that the driver is in the normal non-eco state, and as a result, the uncomfortable feeling given to the driver can be suppressed or alleviated.

(4) Also, in this example, as shown in steps S23 to S25 in FIG. 6D, when a sudden braking operation is detected, the notification that the vehicle is in the non-eco state is prohibited or the pedal vibration amplitude A is multiplied. Since the gain g to be set is set to a value less than 1.0 (for example, 0.5) to reduce the notification amount indicating that the vehicle is in the non-eco state, the driver can concentrate on the driving operation.

(5) In this example, as shown in steps S28 to S30 of FIG. 6D, when the battery temperature of the high-power battery 12 is equal to or lower than the low temperature limit temperature TBlim, the determination threshold set in step S9 to increase the determination threshold The determination target value Ts set in step S8 to reduce Tlim or the determination target value is replaced with the pseudo friction braking torque Tfb_map obtained from the driver required braking torque Treq and the vehicle speed V when the control for suppressing the turning state does not intervene. As a result, even if the actual friction braking torque increases, if it is in the eco state until then, it is evaluated as the eco state, and no false notification of the non-eco state is made. In addition to or instead of this, when the battery temperature of the high-power battery 12 is equal to or lower than the low-temperature limit temperature TBlim, the gain g multiplied by the vibration amplitude A of the brake pedal 21 is reduced, and the non-eco state is set. Reduce the amount of notification to that effect. As a result, the driver can be distinguished from the notification that the driver is in the normal non-eco state, and as a result, the uncomfortable feeling given to the driver can be suppressed or alleviated.

(6) In this example, as shown in steps S31 to S33 in FIG. 6D, when the SOC value of the high-power battery 12 exceeds the limit value Slim, the determination threshold set in step S9 to increase the determination threshold The determination target value Ts set in step S8 to reduce Tlim or the determination target value is replaced with the pseudo friction braking torque Tfb_map obtained from the driver required braking torque Treq and the vehicle speed V when the control for suppressing the turning state does not intervene. As a result, even if the actual friction braking torque increases, if it is in the eco state until then, it is evaluated as the eco state, and no false notification of the non-eco state is made. In addition to or instead of this, when the SOC value of the high-power battery 12 exceeds the limit value Slim, the gain g by which the vibration amplitude A of the brake pedal 21 is multiplied is reduced, and in the non-eco state. Reduce the amount of notification to that effect. As a result, the driver can be distinguished from the notification that the driver is in the normal non-eco state, and as a result, the uncomfortable feeling given to the driver can be suppressed or alleviated.

(7) Further, in this example, as shown in steps S36 to S38 in FIG. 6D, when the shift-up state of the transmission 42 is detected, the determination threshold Tlim or the determination target set in step S9 to increase the determination threshold The determination target value Ts set in step S8 to reduce the value is replaced with the pseudo friction braking torque Tfb_map obtained from the driver requested braking torque Treq and the vehicle speed V when the control for suppressing the turning state does not intervene. As a result, even if the actual friction braking torque increases, if it is in the eco state until then, it is evaluated as the eco state, and no false notification of the non-eco state is made. In addition to or instead of this, when the shift-up state of the transmission 42 is detected, the gain g multiplied by the vibration amplitude A of the brake pedal 21 is reduced to notify that the vehicle is in the non-eco state. Reduce the amount. As a result, the driver can be distinguished from the notification that the driver is in the normal non-eco state, and as a result, the uncomfortable feeling given to the driver can be suppressed or alleviated.

  The VCU 50 corresponds to a friction braking force command value calculation unit, a friction braking force calculation unit, a selection unit, a threshold setting unit, a notification unit, a detection unit, and a switching unit according to the present invention.

11 ... Electric motor (motor / generator)
12 ... High-power battery 13 ... Inverter 14 ... Motor control unit (MCU)
DESCRIPTION OF SYMBOLS 15 ... Battery temperature sensor 16 ... Accelerator pedal sensor 17 ... Vehicle speed sensor 21 ... Brake pedal 22 ... Brake rotor 23 ... Brake caliper 24 ... Brake sensor 25 ... Brake master cylinder 26 ... Brake fluid piping 27 ... Reservoir tank 28 ... Electric brake booster 29 ... VDC actuator 30 ... VDC control unit (VDCCU)
31 ... Wheel speed sensor 32 ... Yaw rate sensor 33 ... Rudder angle sensor 34 ... Lateral G sensor 41 ... Drive wheel 42 ... Automatic transmission 43 ... Differential gear 44 ... Drive shaft 45 ... Transmission control unit (TACU)
50 ... Vehicle control unit (VCU)

Claims (4)

An electric motor as a travel drive source; a battery that supplies electric power to the electric motor and stores regenerative electric power from the electric motor; and a hydraulic friction brake, and a braking force according to a depression amount of a brake pedal is applied to the electric motor. In a vehicle brake control device for controlling the braking force with respect to a vehicle that is generated by the regenerative braking force and the hydraulic friction brake and stores regenerative power by the electric motor in the battery,
A calculation means for calculating a judgment target value of an actual braking force based on a required braking force corresponding to a depression amount of the brake pedal;
Threshold setting means for setting a threshold for determining a braking force for determining whether or not the driving operation of the vehicle including the braking operation is in an eco state;
It is determined whether or not the determination target value is larger than the determination threshold value, and when the determination target value is larger than the determination threshold value, a notification that notifies that the driving operation of the vehicle including the braking operation is not in an eco state is performed. Means,
Detecting means for detecting an operation of braking control for suppressing an understeer tendency or an oversteer tendency of the vehicle;
When detecting an operation of braking control that suppresses the understeer tendency or the oversteer tendency, the threshold value setting means increases the determination threshold value, the calculation means decreases the determination target value, or the notification means A vehicular braking control apparatus comprising: switching means for reducing a notification amount.   When the switching means detects an operation of braking control that suppresses the understeer tendency or the oversteer tendency, the switching means sets the judgment threshold value of the threshold setting means or the judgment target value of the calculation means to the demanding power and the vehicle. The vehicular brake control device according to claim 1, wherein the vehicular brake control device is set to a pseudo friction braking force when there is no braking control operation for suppressing the understeer tendency or the oversteer tendency based on speed.   When the switching means detects an operation of braking control that suppresses the understeer tendency or the oversteer tendency and then detects the end of the operation, the switching means maintains the switching state until the braking operation ends, and then returns to the original switching state. The vehicle brake control device according to claim 1 or 2, wherein The calculating means includes
A differential braking force calculation unit that calculates a differential braking force between a required braking force based on a depression amount of the brake pedal and an actual regenerative braking force of the electric motor according to a traveling state of the vehicle;
A friction braking force calculation unit for calculating a friction braking force of the friction brake based on a hydraulic pressure of the hydraulic friction brake;
The vehicle brake control device according to any one of claims 1 to 3, further comprising a selection unit that selects a smaller value of the differential braking force and the friction braking force and sets the value as a determination target value.

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