JP5915840B2 - Brake control device for vehicle - Google Patents

Description

  The present invention relates to a braking control device for a vehicle.

  2. Description of the Related Art Conventionally, a vehicle braking control device that generates braking torque by an electric motor is known. In this type of apparatus, normally, an instruction current (target current) is calculated based on an operation amount of a braking operation member of a vehicle by a driver, and an electric motor is controlled based on the instruction current. Thereby, the braking torque according to operation of the braking operation member is provided to a wheel.

  In this type of device, due to the influence of the inertia of the entire device including the inertia of the electric motor (moment of inertia, mass of inertia), particularly during sudden braking (when the braking torque suddenly increases), etc. Response delay (rise delay) of braking torque at the time of acceleration (for example, when the electric motor starts up) when the rotation speed increases, and deceleration (for example, the electric motor goes to stop) when the rotation speed of the electric motor decreases. Overshoot of the braking torque can occur. Therefore, particularly during sudden braking, the influence of the inertia is compensated, that is, the braking torque response (rise performance) during acceleration of the electric motor is improved, and the braking torque overshoot when the electric motor is decelerated. Suppression (improvement of convergence) is desired.

  In order to deal with this problem, for example, Patent Document 1 describes the following. That is, based on a map that defines the relationship between the command current and the target motor rotation angle, the target motor rotation angle corresponding to the calculated command current is obtained, and the target motor rotation angle is second-order differentiated to obtain the target The motor rotation angular acceleration is determined. Based on this target motor rotation angular acceleration, an inertia compensation current for compensating for the influence of the inertia of the entire apparatus is calculated. In this case, the inertia compensation current is calculated as a positive value when the electric motor is accelerated, and is calculated as a negative value when the electric motor is decelerated. This inertia compensation current is added to the command current, and the post-compensation command current (target current) is determined. As a result, when the electric motor is started, the post-compensation command current is calculated to be larger than the command current, and the braking torque response can be improved. When the electric motor heads to stop, the post-compensation command current is calculated to be smaller than the command current, and the braking torque overshoot can be suppressed.

  Further, Patent Document 1 also describes that, in order to perform stable control, when the command current exceeds the capacity of the electric motor, a “slope limit” is provided for the command current.

JP 2002-225690 A

  By the way, as described in the above document, when the inertia compensation current is calculated based on the target motor rotation angular acceleration calculated from the command current, if the tilt limit is provided for the command current, it is obtained based on the command current. The target motor rotation angle acceleration obtained by second-order differentiation of the target motor rotation angle to be obtained cannot be properly calculated. For example, when the command current is limited by a certain slope limit value, the target motor rotation angular acceleration corresponding to the second-order differential value of the command current is maintained at “zero (0)”. As a result, proper (high accuracy) compensation of the influence of the inertia may be difficult.

  Hereinafter, this will be described with reference to FIG. In the example shown in FIG. 8, the electric motor is started at time t0, and from the “time point after a short period of time t0” to “the original instruction current (see the solid line) and the instruction current (indicated by the dashed line) The indicated current is limited by a certain slope limit value until “time t1” at which “see” intersects. In this case, the rotation speed of the electric motor increases only during the short period from time t0 (thus, positive target motor rotation angular acceleration occurs), and the rotation speed of the electric motor decreases only during the extremely short period from time t1. (Thus, a negative target motor rotational angular acceleration occurs), and the rotational speed of the electric motor is kept constant during other periods (thus, the target motor rotational angular acceleration is maintained at zero (0)). That is, as shown in FIG. 8, a positive inertia compensation current is generated only during the short period from time t0, a negative inertia compensation current is generated during the very short period from time t1, and the inertia compensation current is generated during the other periods. Is maintained at zero (0).

  For this reason, the response of the braking torque when the electric motor is accelerated cannot be sufficiently improved, and the overshoot of the braking torque when the electric motor is decelerated cannot be sufficiently suppressed. Further appropriate compensation for the influence of the inertia is desired.

  The present invention has been made to address the above-described problems, and an object of the present invention is a vehicle braking control device that generates a braking torque by an electric motor, and the influence of the inertia of the entire device including the inertia of the electric motor. It is to provide what can compensate appropriately.

  The vehicle braking control apparatus according to the present invention includes an operation amount acquisition means (BPA) for acquiring an operation amount (Bpa) of a braking operation member (BP) of a vehicle by a driver, and a braking torque for the vehicle wheel (WHL). Is generated by an electric motor (MTR) and a target energization amount (Imt) is calculated based on the operation amount (Bpa), and the electric motor (MTR) is calculated based on the target energization amount (Imt). ) And a power supply amount acquisition means (IMA) for acquiring an actual power supply amount (Ima) of the electric motor (MTR).

The present invention is characterized in that the control means (CTL) has the following configuration. Whether or not inertia compensation control is required to compensate for the influence of inertia of the braking means (BRK) at the time of acceleration at which the speed (for example, rotational speed) of the electric motor increases based on the operation amount (Bpa) Is determined. When it is determined that the inertia compensation control at the time of acceleration is necessary (FLj ← 1), the first energization amount (Imt) is increased to compensate for the influence of the inertia of the braking means (BRK). The inertia compensation energization amount (Ijt) is calculated. Whether or not inertia compensation control for compensating for the influence of inertia of the braking means (BRK) at the time of deceleration at which the speed (for example, rotational speed) of the electric motor decreases based on the operation amount (Bpa) is required. Is determined. When it is determined that the inertia compensation control at the time of acceleration is necessary, and it is determined that the inertia compensation control at the time of deceleration is necessary (FLk ← 1), the first inertia compensation energization amount (Ijt) Second inertia compensation energization for reducing the target energization amount (Imt) and compensating for the inertia of the braking means (BRK) based on the actual energization amount (Ima) acquired correspondingly. A quantity (Ikt) is calculated. The target energization amount (Imt) is calculated based on the first and second inertia compensation energization amounts (Ijt, Ikt).

Here, based on the manipulated variable (Bpa), at least one of the acceleration equivalent value and the speed equivalent value is calculated, and the state equivalent values (ddBp, ddFb, ddMk, dBp, DFB, based on dMk), of whether the it is necessary to accelerate the inertia compensation control during the determination, and, during the deceleration inertia compensation control during the acceleration is executed if it is determined to be necessary At least one of the determination of whether inertia compensation control is necessary can be performed .

  Depending on the state of the power supply voltage and the like, the actual energization amount of the electric motor does not always match the target energization amount. According to the above configuration, when the inertia compensation control at the time of acceleration is executed, based on the actual energization amount (for example, current value) acquired by the energization amount acquisition unit (for example, current sensor), The inertia compensation energization amount can be calculated. Therefore, the inertia compensation control especially during deceleration can be appropriately executed regardless of the situation such as the power supply voltage. As a result, the influence of the inertia of the entire apparatus including the inertia of the electric motor can be appropriately compensated.

  In the braking control device, when the control means (CTL) determines that the inertia compensation control at the time of acceleration is necessary (FLj ← 1), the first inertia compensation energization amount (Ijt) It is set in advance based on a change in the actual position of the electric motor (MTR) when the step input of the target energization amount (Imt) is made to the electric motor (MTR) (for example, actual rotational angular acceleration). It is preferable that the first inertia compensation energization amount (Ijt) is calculated using the time series pattern (CHj).

  In this case, the control means (CTL) generates the time-series pattern (CHj) based on the actual energization amount (Ima) acquired corresponding to the first inertia compensation energization amount (Ijt). When corresponding time series data (Jdk) is acquired and it is determined that the inertia compensation control at the time of deceleration is necessary (FLk ← 1), the second inertia compensation energization is performed based on the time series data (Jdk). It may be configured to calculate a quantity (Ikt).

  In order to ensure the response of braking torque during acceleration (especially during startup) of the electric motor, the electric motor is compensated for the effects of static friction such as bearings of the electric motor and the inertia of the entire device. It is important to improve the start of movement (start of movement from the stop state). According to the above configuration, the time-series pattern (corresponding to the passage of time) set in advance corresponding to the maximum response of the braking means BRK after the determination that the inertia compensation control during acceleration is necessary is made. Waveform) inertia compensation energization amount can be output. Accordingly, the inertia of the entire apparatus including the electric motor and the influence of static friction such as bearings are compensated, and the response of the braking torque when the electric motor starts to move can be improved efficiently.

1 is a schematic configuration diagram of a vehicle equipped with a braking control device according to an embodiment of the present invention. It is a figure for demonstrating the structure of the braking means (brake actuator) (Z section) shown in FIG. It is a functional block diagram for demonstrating the control means (brake controller) shown in FIG. It is a functional block diagram for demonstrating embodiment of the inertia compensation control block shown in FIG. FIG. 5 is a functional block diagram for explaining an example of a control necessity determination calculation block and an acceleration energization amount calculation block shown in FIG. 4. It is a figure for demonstrating the maximum response of a braking means (brake actuator). FIG. 5 is a functional block diagram for explaining another example of the control necessity determination calculation block and the acceleration energization amount calculation block shown in FIG. 4. It is the time chart which showed an example of the calculation result of the inertia compensation current in case the inclination limitation is provided in the command current by the conventional braking control device.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a vehicle braking control apparatus according to the present invention will be described with reference to the drawings.

<Configuration of Entire Vehicle Equipped with Vehicle Brake Control Device According to the Present Invention>
As shown in FIG. 1, in this vehicle, a braking operation member (for example, a brake pedal) BP that is operated by a driver to decelerate the vehicle, and a braking force is generated on each wheel by adjusting the braking torque of each wheel. An electronic control unit ECU for controlling the braking means (brake actuator) BRK, BRK to be operated, and a storage battery BAT as a power source for supplying power to the BRK, ECU and the like are mounted.

  In addition, the vehicle includes a braking operation amount acquisition unit (for example, a stroke sensor and a pedal force sensor) BPA that detects an operation amount Bpa of the BP, a steering angle detection unit SAA that detects an operation angle Saa of the steering wheel SW by the driver, Yaw rate detecting means YRA for detecting the yaw rate Yra of the vehicle, longitudinal acceleration detecting means GXA for detecting the longitudinal acceleration Gxa of the vehicle, lateral acceleration detecting means GYA for detecting the lateral acceleration Gya of the vehicle, and rotational speeds of the wheels WHL (wheels Wheel speed detection means VWA for detecting (speed) Vwa is provided.

  The braking means BRK is provided with an electric motor MTR (not shown), and the braking torque of the wheel WHL is controlled by the MTR. Further, the BRK includes an energization amount detection unit (for example, an axial force sensor) FBA and an MTR energization amount (for example, current value) Ima for detecting a force Fba for the friction member to push the rotation member. For example, position detection means (for example, a rotation angle sensor) MKA for detecting the position (for example, the rotation angle) Mka of the current sensors IMA and MTR is provided.

  The detection signals (Bpa and the like) from the various detection means described above are processed by a noise removal (reduction) filter (for example, a low-pass filter) and supplied to the ECU. In the ECU, a braking control calculation process according to the present invention is executed. That is, a control means CTL described later is programmed in the ECU, and a target energization amount (for example, target current value, target duty ratio) Imt for controlling the electric motor MTR is calculated based on Bpa or the like. Further, the ECU executes arithmetic processing such as known anti-skid control (ABS), traction control (TCS), and vehicle stabilization control (ESC) based on Vwa, Yra, and the like.

<Configuration of braking means (brake actuator) BRK>
In the braking control device according to the present invention, generation and adjustment of the braking torque of the wheel WHL is performed by the electric motor MTR.

  As shown in FIG. 2, which is an enlarged view of the Z portion in FIG. 1, the braking means BRK includes a brake caliper CPR, a rotating member KTB, a friction member MSB, an electric motor MTR, a driving means DRV, a speed reducer GSK, and rotation / linear motion. The conversion mechanism KTH, the pressing force acquisition means FBA, the position detection means MKA, and the energization amount acquisition means IMA are configured.

  The brake actuator BRK is provided with a known brake caliper CPR and a friction member (for example, a brake pad) MSB, similarly to a known braking device. When the MSB is pressed against a known rotating member (for example, a brake rotor) KTB, a frictional force is generated, and a braking torque is generated on the wheel WHL.

  The drive means (drive circuit for the electric motor MTR) DRV controls the energization amount (finally the current value) to the electric motor MTR based on the target energization amount (target value) Imt. Specifically, a bridge circuit using a power transistor (for example, a MOS-FET) is configured in the driving unit DRV, the power transistor is driven based on the target energization amount Imt, and the output of the electric motor MTR is controlled. Is done.

  The output (output torque) of the electric motor MTR is transmitted to the rotation / linear motion conversion mechanism KTH via a reduction gear (for example, a gear) GSK. Then, the rotational motion is converted into a linear motion by KTH, and the friction member (brake pad) MSB is pressed against the rotational member (brake disc) KTB. The KTB is fixed to the wheel WHL, and braking torque is generated in the wheel WHL due to friction between the MSB and the KTB, and is adjusted. As the rotation / linear motion conversion mechanism KTH, a slide screw (for example, a trapezoidal screw) that performs power transmission (slip transmission) by “sliding” or a ball screw that performs power transmission (rolling transmission) by “rolling” can be used.

  The motor drive circuit DRV includes an energization amount acquisition unit (for example, a current sensor) IMA that detects an actual energization amount (for example, an electric current that actually flows through the electric motor) Ima. Further, the electric motor MTR is provided with position detecting means (for example, an angle sensor) MKA that detects a position (for example, a rotation angle) Mka. Further, a pressing force acquisition means (for example, a force sensor) FBA is provided in order to acquire (detect) a force (actual pressing force) Fba that the friction member MSB actually presses the rotating member KTB.

  In FIG. 2, a configuration of a so-called disc type braking device (disc brake) is illustrated as the braking unit BRK, but the braking unit BRK may be a drum type braking device (drum brake). In the case of a drum brake, the friction member MSB is a brake shoe, and the rotating member KTB is a brake drum. Similarly, the force (pressing force) by which the brake shoe presses the brake drum is controlled by the electric motor MTR. An electric motor MTR that generates torque by rotational motion is shown, but a linear motor that generates force by linear motion may be used.

<Overall configuration of control means CTL>
As shown in FIG. 3, the control means CTL shown in FIG. 1 includes a target pushing force calculation block FBT, an instruction energization amount calculation block IST, a pushing force feedback control block IPT, an inertia compensation control block INR, and an energization amount adjustment calculation. It is composed of block IMT. The control means CTL is programmed in the electronic control unit ECU.

  An operation amount Bpa of the braking operation member BP (for example, a brake pedal) is acquired by the braking operation amount acquisition means BPA. The operation amount (brake operation amount) Bpa of the brake operation member is based on at least one of the operation force (for example, brake pedal force) of the brake operation member by the driver and the displacement amount (for example, brake pedal stroke). Calculated. Bpa is subjected to arithmetic processing such as a low-pass filter, and noise components are removed (reduced).

  In the target pushing force calculation block FBT, the target pushing force Fbt is calculated based on the operation amount Bpa using a preset target pushing force calculation characteristic (calculation map) CHfb. The “pushing force” is the pushing force of the friction member (for example, brake pad) MSB to the rotating member (for example, brake disc) KTB in the braking means (brake actuator) BRK. The target pushing force Fbt is a target value of the pushing force.

  In the command energization amount calculation block IST, the command energization amount Ist is calculated based on the target pushing force Fbt using preset calculation maps CHs1 and CHs2. The command energization amount Ist is a target value of the energization amount to the electric motor MTR for driving the electric motor MTR of the braking means BRK and achieving the target pushing force Fbt. The calculation map (the calculation characteristic of the command energization amount) is composed of two characteristics CHs1 and CHs2 in consideration of the hysteresis of the brake actuator. The characteristic (first instruction energization amount calculation characteristic) CHs1 corresponds to the case where the pushing force is increased, and the characteristic (second instruction energization amount calculation characteristic) CHs2 corresponds to the case where the pushing force is reduced. Therefore, compared with the characteristic CHs2, the characteristic CHs1 is set to output a relatively large command energization amount Ist.

  Here, the energization amount is a state amount (variable) for controlling the output torque of the electric motor MTR. Since the electric motor MTR outputs a torque approximately proportional to the current, the current target value of the electric motor can be used as the target value of the energization amount. Further, if the supply voltage to the electric motor MTR is increased, the current is increased as a result, so that the supply voltage value can be used as the target energization amount. Furthermore, since the supply voltage value can be adjusted by the duty ratio in pulse width modulation (PWM), this duty ratio can be used as the energization amount.

  In the pressing force feedback control block IPT, the pressing force feedback energization amount Ipt is calculated based on the target pressing force (target value) Fbt and the actual pressing force (actual value) Fba. The command energization amount Ist is calculated as a value corresponding to the target pressing force Fbt, but an error (steady error) may occur between the target pressing force Fbt and the actual pressing force Fba due to fluctuations in the efficiency of the brake actuator. is there. The pushing force feedback energization amount Ipt is calculated based on a deviation (pushing force deviation) ΔFb between the target pushing force Fbt and the actual pushing force Fba, and a calculation characteristic (calculation map) CHp. ) To be reduced. Note that Fba is acquired by the pressing force acquisition means FBA.

  Inertia compensation control block INR compensates for the influence of the inertia of BRK (particularly, electric motor MTR) (inertia, inertia moment in rotational motion, or inertia mass in linear motion). In the inertia compensation control block INR, target values Ijt and Ikt of the energization amount for compensating for the influence of the BRK inertia (moment of inertia or mass of inertia) are calculated. When the electric motor is stopped or the motion (rotational motion) is accelerated from a state where the electric motor is moving at a low speed, it is necessary to improve the responsiveness of generating the pushing force. The acceleration inertia compensation energization amount Ijt corresponding to this case is calculated. Ijt is a target value of the energization amount of the acceleration control in the inertia compensation control.

  In addition, when the electric motor is decelerated and stopped from the state of motion (rotational motion), it is also necessary to suppress the overshoot of the pushing force and improve the convergence. A deceleration inertia compensation energization amount Ikt corresponding to this case is calculated. Ikt is a target value of the energization amount in the deceleration control in the inertia compensation control. Here, Ijt is a value that increases the energization amount of the electric motor (a positive value that is added to Ist), and Ikt is a value that decreases the energization amount of the electric motor (a negative value that is added to Ist). .

  In the energization amount adjustment calculation block IMT, the command energization amount Ist is adjusted by the pushing force feedback energization amount Ipt, the inertia compensation energization amount Ijt (acceleration), and Ikt (deceleration), and the target energization amount Imt is obtained. Calculated. Specifically, the feedback energization amount Ipt and the inertia compensation energization amounts Ijt and Ikt are added to the command energization amount Ist, and the sum is calculated as the target energization amount Imt. The target energization amount Imt is a final energization amount target value for controlling the output of the electric motor MTR.

<Configuration of Embodiment of Inertia Compensation Control Block>
An embodiment of the inertia compensation control block INR will be described with reference to FIG. As shown in FIG. 4, the inertia compensation control block INR includes a control necessity determination calculation block FLG that determines whether or not inertia compensation control is necessary, an inertia compensation energization amount calculation block IJK that calculates a target energization amount of inertia compensation control, and The selection calculation block SNT.

  In the control necessity determination calculation block FLG, it is determined whether the inertia compensation control needs to be executed or not. The control necessity determination calculation block FLG includes an acceleration determination calculation block FLJ for determining necessity during acceleration (for example, when the electric motor starts and accelerates), and deceleration (for example, the electric motor stops). (Deceleration determination calculation block FLK) for determining whether or not it is necessary. From the control necessity determination calculation block FLG, necessity determination flags FLj (acceleration) and FLk (deceleration) are output as determination results. The necessity determination flag FLj indicates the necessity determination result of the inertia compensation control during acceleration, and “0” is output when the control is unnecessary, and “1” is output when necessary. The necessity determination flag FLj represents the necessity determination result of the inertia compensation control at the time of deceleration, and “0” is output when the control is unnecessary and “1” is output when necessary. Details of the necessity determination of the inertia compensation control (control necessity determination calculation block FLG) will be described later.

  In the inertia compensation energization amount calculation block IJK, the inertia compensation energization amount (target value) in the case where it is determined by the FLG that the inertia compensation control is necessary (when FLj = 1 or FLk = 1) is calculated. . The inertia compensation energization amount calculation block IJK includes an acceleration energization amount calculation block IJT for calculating an inertia compensation energization amount (target value) Ijt at the time of acceleration (for example, when the electric motor starts and accelerates), and at the time of deceleration. For example, a deceleration energization amount calculation block IKT that calculates an inertia compensation energization amount (target value) Ikt (for example, when the electric motor heads to stop) is configured.

  In the selection calculation block SNT, the output of the inertia compensation energization amount Ijt during acceleration of the electric motor, the output of the inertia compensation energization amount Ikt during deceleration of the electric motor, and the control stop (output of the value “0”) are: Either one is selected and output. In the selection calculation block SNT, when the deceleration inertia compensation energization amount Ikt is output while the acceleration inertia compensation energization amount Ijt is being output, Ikt is preferentially output instead of Ijt. Inertia compensation control is performed using the “necessary state” determination (necessity determination flag) as a trigger, but when the driver stops sudden braking, inertia compensation control (Ijt calculation) during acceleration is immediately performed. Stopped and switched to inertia compensation control (calculation of Ikt) during deceleration. Therefore, the overshoot of the pushing force can be reliably suppressed.

  Even if the acceleration inertia compensation energization amount Ijt is output as a value that takes into account the responsiveness of the electric motor MTR, the actual energization of the electric motor MTR depends on the state of the power supply voltage (for example, when there is a voltage drop). The amount does not always match the target value. For example, in the case where the actual energization amount is insufficient when the electric motor MTR is started, if the preset inertia compensation energization amount Ikt during deceleration is output, the brake actuator BRK may have insufficient pressing force. possible. In order to cope with such a problem, the deceleration inertia compensation energization amount Ikt is calculated based on the actual energization amount (for example, current value) Ima acquired by the energization amount acquisition means (for example, current sensor) IMA. Details of the calculation of the inertia compensation energization amount Ijt during acceleration will be described later.

  The actual energization amount Ima corresponding to the inertia compensation energization amount Ijt at the time of acceleration is acquired by the energization amount acquisition means (for example, current sensor) IMA. The deceleration energization amount calculation block IKT is provided with a data storage calculation block JDK, and time series data Jdk based on the actual energization amount Ima is stored while Ijt is output. The time series data Jdk is stored as a characteristic of the actual energization amount Ija with respect to the time passage T. Based on the characteristic Jdk, an inertia compensation energization amount Ikt during deceleration is calculated.

  Specifically, in the deceleration energization amount calculation block IKT, the command energization amount Ist and the feedback energization amount Ipt are subtracted from the actual energization amount Ima to correspond to inertia compensation during acceleration (that is, the target value Ijt). The actual energization amount Ija is calculated. The component due to Ist and the component due to Ipt are removed from Ima, and the energization amount Ija corresponding to Ijt is calculated. Then, the corresponding energization amount Ija is multiplied by “−1” (the sign is inverted), and further multiplied by a coefficient k_ij to calculate the stored energization amount Ikb.

  In the data storage calculation block JDK, the storage energization amount Ikb has elapsed since the time when the acceleration control necessity determination flag FLj transited from “0 (unnecessary state)” to “1 (necessary state)” (T = 0). It is stored as time-series data Jdk in association with time (that is, elapsed time from the start of inertia compensation control during acceleration) T. The stored time series data Jdk is used as a characteristic (calculation map) for calculating the inertia compensation energization amount Ikt during deceleration. The time-series data Jdk based on the elapsed time T from the time (T = 0) when the necessity determination flag FLk for deceleration control is switched from “0 (unnecessary state)” to “1 (necessary state)” and Ima Based on this, the inertia compensation energization amount Ikt during deceleration is calculated.

  When accelerating (especially when starting), it is necessary to generate torque that overcomes the friction of the bearings of the electric motor MTR, but when decelerating (when stopping), the friction acts to decelerate the MTR. Therefore, the coefficient k_ij can be set to a value less than “1”. In the above description, the storage energization amount Ikb is calculated for each calculation cycle. The values of Ima, Ist, and Ipt corresponding to the elapsed time T are stored as time series data, and the characteristics are used using these. Jdk can be computed. That is, characteristics (calculation map) based on the calculation of time series data Jdk = (− 1) × (k_ij) × {(Ima time series data) − (Ist time series data) − (Ipt time series data)}. ) Jdk may be determined.

  According to this embodiment of the INR, the inertia compensation control at the time of deceleration is executed based on the actual energization amount Ima when the inertia compensation control at the time of acceleration is performed. Even if an error occurs between the values, appropriate inertia compensation control can be executed.

<Example of control necessity determination calculation block and acceleration energization amount calculation block>
An example of the control necessity determination calculation block FLG and the acceleration energization amount calculation block IJT will be described with reference to FIG. As shown in FIG. 5, in this inertia compensation control block INR, inertia compensation control for improving the responsiveness and convergence of the pressing force caused by the inertia such as MTR is executed. The inertia compensation control block INR is a control necessity determination calculation block FLG that determines whether or not inertia compensation control is necessary, an inertia compensation energization amount calculation block IJK that calculates a target energization amount of inertia compensation control, and a selection calculation block SNT. Composed.

  In the control necessity determination calculation block FLG, it is determined whether the inertia compensation control needs to be executed or not. The control necessity determination calculation block FLG includes an acceleration determination calculation block FLJ for determining necessity during acceleration (for example, when the electric motor starts and accelerates), and deceleration (for example, the electric motor stops). (Deceleration determination calculation block FLK) for determining whether or not it is necessary. From the control necessity determination calculation block FLG, necessity determination flags FLj (acceleration) and FLk (deceleration) are output as determination results. In the necessity determination flags FLj and FLk, “0” represents a case where inertia compensation control is not required (unnecessary state), and “1” represents a case where inertia compensation control is necessary (necessary state).

  The control necessity determination calculation block FLG includes an operation speed calculation block DBP, an acceleration determination calculation block FLJ, and a deceleration determination calculation block FLK.

  First, in the operation speed calculation block DBP, the operation speed dBp is calculated based on the operation amount Bpa of the braking operation member BP. The operation speed dBp is calculated by differentiating Bpa.

  In the acceleration determination calculation block FLJ, the inertia compensation control when the electric motor accelerates based on the operation speed dBp (for example, when the electric motor increases the rotation speed) is “necessary state (state where control needs to be executed). ) "And" Unnecessary state (state where control is not required to be executed) ". The determination result is output as a necessity determination flag (control flag) FLj. As the necessity determination flag FLj, “0” corresponds to “unnecessary state” and “1” corresponds to “necessary state”. Whether the inertia compensation control during acceleration is necessary is determined according to the calculation map CFLj, when the acceleration necessity determination flag FLj is “0 (unnecessary state)” when dBp exceeds a predetermined operation speed (predetermined value) db1. It is switched to “1 (necessary state)” (FLj ← 1). After that, the necessity determination flag FLj is switched from “1” to “0” (FLj ← 0) when dBp becomes less than the predetermined operation speed (predetermined value) db2. Note that FLj is set to “0” as an initial value when a braking operation is not performed.

  Furthermore, in addition to the operation speed dBp, the operation amount Bpa of the brake operation member can be used for determining whether or not the acceleration inertia compensation control is necessary. In this case, the necessity determination flag FLj switches from “0” to “1” when Bpa exceeds the predetermined operation amount (predetermined value) bp1 and dBp exceeds the predetermined operation speed (predetermined value) db1. It is done. Since the condition of Bpa> dp1 is used as a determination criterion, the influence of noise or the like in dBp is compensated, and a reliable determination can be performed.

  In the deceleration determination calculation block FLK, the inertia compensation control when the electric motor decelerates based on dBp (for example, when the electric motor reduces the rotation speed) is “necessary state (state where control needs to be executed)”. , And “unnecessary state (a state in which it is not necessary to execute control)” is determined. The determination result is output as a necessity determination flag (control flag) FLk. In the necessity determination flag FLk, “0” corresponds to “unnecessary state” and “1” corresponds to “necessary state”. Necessity determination of inertia compensation control at the time of deceleration is necessary at the time when dBp becomes less than the predetermined operation speed (predetermined value) db4 (<db3) from the state where the dBp is equal to or higher than the predetermined operation speed (predetermined value) db3 according to the calculation map CFLk. The rejection determination flag FLk is switched from “0 (unnecessary state)” to “1 (necessary state)” (FLk ← 1). Thereafter, in order to prevent the dBp from frequently repeating the acceleration control and the deceleration control, the predetermined operation speed db3 of the deceleration control can be set to a value smaller than the predetermined operation speed db1 of the acceleration control. Note that FLk is set to “0” as an initial value when a braking operation is not performed.

  The necessity determination flags FLj and FLk for inertia compensation control are transmitted from the control necessity determination calculation block FLG to the inertia compensation energization amount calculation block IJK.

  In the inertia compensation energization amount calculation block IJK, the inertia compensation energization amount (target value) in the case where it is determined by the FLG that the inertia compensation control is necessary (when FLj = 1 or FLk = 1) is calculated. . The inertia compensation energization amount calculation block IJK includes an acceleration energization amount calculation block IJT that calculates an inertia compensation energization amount Ijt at the time of acceleration (for example, when the electric motor starts and accelerates), and at the time of deceleration (for example, electric This is composed of a deceleration energization amount calculation block IKT that calculates an inertia compensation energization amount Ikt (when the motor heads to stop).

  In the acceleration energization amount calculation block IJT, the acceleration inertia compensation energization amount (first inertia compensation) based on the necessity determination flag FLj and the acceleration calculation characteristic (calculation map, corresponding to a time-series pattern) CHj. The energization amount) Ijt is calculated. The acceleration calculation characteristic CHj is stored in advance in the ECU as a characteristic (calculation map) of Ijt with respect to the elapsed time T from the time when the necessity state of acceleration inertia compensation control is determined. In the calculation characteristic CHj, Ijt is sharply increased from “0” to a predetermined energization amount (predetermined value) ij1 as time elapses from the time T is “0”, and then Ijt is predetermined energization as time elapses. The amount (predetermined value) is gradually decreased from ij1 to “0”. Specifically, CHj is a time tdn that is required for Ijt to be increased from “0” to the predetermined energization amount ij1, and that is required for Ijt to be decreased from the predetermined energization amount ij1 to “0”. Is set shorter.

  Further, as indicated by a broken line in FIG. 5, when the energization amount increases, Ijt has a “convex upward” characteristic, and is initially increased rapidly, and then CHj can be set as a characteristic that gradually increases. . Further, when the energization amount decreases, Ijt has a “convex downward” characteristic, and is initially abruptly decreased. Thereafter, CHj can be set as a characteristic that gradually decreases. The time point at which the necessity determination flag FLj is switched from “0 (unnecessary state)” to “1 (necessary state)” is defined as the origin of the elapsed time at CHj (T = 0), and the elapsed time T from the switching point. And the acceleration calculation characteristic CHj, the inertia compensation energization amount (first inertia compensation energization amount) Ijt during acceleration of the electric motor is determined. Even when the necessity determination flag FLj is switched from “1” to “0” during the calculation of Ijt, the acceleration energization amount Ijt continues to be calculated for the duration set in advance by the calculation characteristic CHj. Note that Ijt is calculated as a positive value, and adjusted so that the amount of current supplied to the electric motor MTR is increased by Ijt.

  Here, the calculation characteristic CHj of the inertia compensation control during acceleration is determined based on the maximum response of the braking means (brake actuator) BRK. The output (displacement of the electric motor) appears later than the change of the input (target energization amount) to the BRK. The maximum response of BRK (the maximum state in which BRK can respond to input) is the response of MTR when a step input is given to electric motor MTR (time change in output corresponding to the time change in input) ). That is, this is a change in the actual displacement (rotation angle) Mka of the MTR when a predetermined amount of the target energization amount Imt is step-inputted (in the increasing direction from zero) to the MTR. As shown in FIG. 6, when the step input of the (predetermined) target energization amount is made to the electric motor MTR (therefore, the target value Mkt of the rotation angle is the step input (of the predetermined amount mks0)), the rotation angle The actual value (output) Mka of the output changes so as to catch up with the target value (input) Mkt (following the target value with a delay). CHj is determined based on this change in Mka.

  The torque that compensates for the inertia of the entire apparatus (in particular, the inertia of the electric motor) is proportional to the rotational angular acceleration of the electric motor. In consideration of this point, in order to appropriately perform inertia compensation, the inertia compensation energization amount is calculated based on the actual acceleration (rotational angular acceleration) ddMka of the electric motor. Therefore, the actual value Mka of the displacement (rotation angle) of the MTR is second-order differentiated, the acceleration (rotation angular acceleration) ddMka is calculated, and CHj is determined based on ddMka. For example, the time-series pattern CHj can be set by multiplying ddMka by a coefficient K (constant).

  In CHj, the increase gradient (the gradient of Ijt with respect to time) when Ijt increases sharply is the increase gradient of ddMka from the start time t1 of the step input to the time t2 when the rotational angular acceleration ddMka reaches the maximum value ddm1. It is determined based on the maximum value or average value of (the slope of ddMka increasing with respect to time). Further, the decrease gradient (gradient of Ijt with respect to time) when Ijt gradually decreases is the decrease gradient of ddMka (with respect to time) from time t2 when ddMka becomes the maximum value dmm1 to time t3 when it becomes approximately zero. It is determined based on the maximum value or the average value of the decreasing ddMka slope.

  Also, based on ddMka in the maximum response (step response) (based on the change in ddMka at time points t1 to t2), when the energization amount is increased, Ijt has a “convex upward” characteristic. CHj can be set as a characteristic that is rapidly increased and then gradually increased. Similarly, based on ddMka in the maximum response (based on the change in ddMka from time t2 to t3), if the energization amount is decreased, Ijt is a “convex downward” characteristic, and is initially rapidly reduced. Thereafter, CHj can be set as a slowly decreasing characteristic.

  In the deceleration energization amount calculation block IKT (see FIG. 4), the deceleration inertia compensation energization amount (second inertia compensation) based on the necessity determination flag FLk and the deceleration calculation characteristic (calculation map) Jdk. Energization amount) Ikt is calculated. The deceleration calculation characteristic Jdk is stored in the data storage calculation block JDK as a characteristic (calculation map) of Ikt with respect to the elapsed time T from the point in time when the necessary state of deceleration inertia compensation control is determined. Then, the time when the necessity determination flag FLk is switched from “0” to “1” is set as the origin of the elapsed time at Jdk (T = 0), and based on the elapsed time T from the switching time and the deceleration calculation characteristic Jdk. Then, the inertia compensation energization amount (second inertia compensation energization amount) Ikt at the time of deceleration of the electric motor is determined. Even if the necessity determination flag FLk is switched from “1” to “0” during the calculation of Ikt, Ikt continues to be calculated for the duration set in advance by the calculation characteristic Jdk. Ikt is calculated as a negative value, and is adjusted so that the amount of current supplied to the electric motor MTR is reduced by Ikt.

  In the selection calculation block SNT, any one of the output of the inertia compensation energization amount Ijt when the electric motor is accelerated, the output of the inertia compensation energization amount Ikt when the electric motor is decelerated, and the control stop (output of the value “0”) One of them is selected and output. In the selection calculation block SNT, when the deceleration inertia compensation energization amount Ikt is output while the acceleration inertia compensation energization amount Ijt is being output, Ikt is preferentially output instead of Ijt. Inertia compensation control is performed using the “necessary state” determination (necessity determination flag) as a trigger, but when the driver stops sudden braking, inertia compensation control (Ijt calculation) during acceleration is immediately performed. Stopped and switched to inertia compensation control (calculation of Ikt) during deceleration. Therefore, the overshoot of the pushing force can be reliably suppressed.

In the control necessity determination calculation block FLG, whether or not the inertia compensation control is necessary is determined based on the operation speed dBp, but instead of dBp, a target pressing force speed dFb obtained by differentiating the target pressing force Fbt can be used. When the displacement (for example, the target rotation angle) Mkt of the electric motor is used as the target value, the target rotation speed dMk obtained by differentiating the target rotation angle Mkt can be used for determining necessity. That is, the necessity of inertia compensation control can be determined based on values (speed equivalent values) dBp, dFb, and dMk corresponding to the operation speed obtained by differentiating the braking operation amount Bpa.
<Other examples of control necessity determination calculation block and acceleration energization amount calculation block>
Other examples of the control necessity determination calculation block FLG and the acceleration energization amount calculation block IJT will be described with reference to FIG. As shown in FIG. 7, the inertia compensation control block INR is composed of a control necessity determination calculation block FLG, an inertia compensation energization amount calculation block IJK, and a selection calculation block SNT. Since the configurations of IJK and SNT are the same as those shown in FIG. 5, only the control necessity determination calculation block FLG will be described.

  The control necessity determination calculation block FLG includes an operation acceleration calculation block DDBP, an acceleration determination calculation block FLJ, and a deceleration determination calculation block FLK.

  In the operation acceleration calculation block DDBP, the operation acceleration ddBp is calculated based on the operation amount Bpa of the braking operation member. The operation acceleration ddBp is calculated by second-order differentiation of Bpa. That is, the operation speed dBp is calculated by differentiating the operation amount Bpa, and further, the operation acceleration ddBp is calculated by differentiating the operation speed dBp.

  In the acceleration determination calculation block FLJ, inertia compensation control when the electric motor MTR accelerates based on the operation acceleration ddBp is “necessary state (state where control needs to be executed)” and “unnecessary state (executes control). It is determined which state is “a state that does not need to be performed”. The determination result is output as a necessity determination flag (control flag) FLj. In the necessity determination flag FLj, “0” corresponds to “unnecessary state” and “1” corresponds to “necessary state”, respectively. According to the calculation map DFLj, when the operation acceleration ddBp exceeds the first predetermined acceleration (predetermined value) ddb1 (> 0), the necessity control flag FLj for acceleration control is changed from “0 (unnecessary state)” to “1”. (Necessary state) "(FLj ← 1). Thereafter, when the operation acceleration ddBp becomes less than a predetermined acceleration (predetermined value) ddb2 (<ddb1), FLj is changed from “1” to “0” (FLj ← 0). Note that FLj is set to “0” as an initial value when a braking operation is not performed.

  In the time reduction determination calculation block FLK, inertia compensation control when the electric motor MTR accelerates based on the operation acceleration ddBp is “necessary state (state where control needs to be executed)” and “unnecessary state (executes control). It is determined which state is “a state that does not need to be performed”. The determination result is output as a necessity determination flag (control flag) FLk. In the necessity determination flag FLk, “0” corresponds to “unnecessary state” and “1” corresponds to “necessary state”. When the operation acceleration ddBp falls below the second predetermined acceleration (predetermined value) ddb3 (<0) according to the calculation map DFLk, the necessity determination flag FLk for deceleration control is changed from “0 (unnecessary state)” to “1”. (Necessary state) "(FLk ← 1). Thereafter, when the operation acceleration ddBp becomes equal to or higher than a predetermined acceleration (predetermined value) ddb4 (> ddb3, <0), FLk is changed from “1” to “0” (FLk ← 0). Note that FLk is set to “0” as an initial value when a braking operation is not performed.

  The necessity determination flags FLj and FLk are transmitted to the inertia compensation energization amount calculation block IJK (IJT and IKT), as in the case shown in FIG. 5, and a time-series preset pattern (calculation map) CHj. Inertia compensation energization amounts Ijt and Ikt are calculated based on Jdk stored according to Ima.

  A delay element calculation block DLY is provided in the control necessity determination calculation block FLG, and a delay element calculation process (for example, first-order delay calculation) is performed on the operation amount Bpa, and ddfBp can be calculated based on the operation amount fBp after the processing. . In the delay element calculation block DLY, the response of the brake actuator BRK (in particular, the electric motor MTR) (the state of the output change with respect to the input change) is taken into account by the transfer function. Specifically, in order to represent the response of the brake actuator BRK, the delay element calculation is performed using the time constant τm as a parameter representing the response speed of the delay element. Since the response of the brake actuator BRK is taken into account, appropriate inertia compensation control can be performed.

  In the control necessity determination calculation block FLG, whether or not the inertia compensation control is necessary is determined based on the operation acceleration ddBp (or ddfBp subjected to the delay calculation process), but instead of ddBp and ddfBp, the target pushing force Fbt is determined. Alternatively, the target pushing force acceleration ddFb (the ddfFb subjected to the delay calculation process) obtained by second-order differentiation of the fFb after the delay calculation process may be used. Further, when the electric motor displacement (for example, the target rotation angle) Mkt is used as the target value, the target rotation obtained by second-order differentiation of the target rotation angle Mkt (or fMk after the delay calculation process) for necessity determination. The acceleration ddMk (the dfMk subjected to the delay calculation process) can be used. That is, based on values (acceleration equivalent values) ddBp, ddFb, ddMk (or ddfBp, ddfFb, ddfMk after delay element calculation processing) corresponding to the acceleration of the braking operation obtained by second-order differentiation of the braking operation amount Bpa. Thus, the necessity of inertia compensation control can be determined.

  In the example shown in FIG. 5, the determination calculation at the time of acceleration (calculation of FLj) and the determination calculation at the time of deceleration (calculation of FLk) are both performed based on the operation speed (speed equivalent value) dBp, etc. In the example shown in FIG. 5, the determination calculation at the time of acceleration (calculation of FLj) and the determination calculation at the time of deceleration (calculation of FLk) are both performed based on the operation acceleration (acceleration equivalent value) ddBp and the like. However, the control necessity determination calculation block FLG can be configured by combining “FLj calculation based on dBp or the like” and “FLk calculation based on ddBp or the like”. Further, “calculation of FLj based on ddBp or the like” and “calculation of FLk based on dBp or the like” can be combined.

  Hereinafter, operations and effects common to the embodiments of the inertia compensation control in the inertia compensation control block INR will be described. In the inertia compensation control, the energization amount (Ijt, Ikt) corresponding to the force (torque) necessary for the movable part (MTR, etc.) of the device having inertia to perform the acceleration motion or the deceleration motion is set as the target energization amount Imt. It is the control which adjusts to. Specifically, when the electric motor accelerates, compensation (correction) is performed by increasing the target energization amount, and when the electric motor decelerates, compensation (correction) is performed by decreasing the target energization amount. Depending on the state of the power supply voltage and the like, the actual energization amount of the electric motor MTR does not always coincide with the target energization amount Imt. According to each of the above embodiments, when the inertia compensation control at the time of acceleration is executed, based on the actual energization amount Ima (for example, current value) acquired by the energization amount acquisition means IMA (for example, current sensor). Thus, the inertia compensation energization amount Ikt during deceleration can be calculated. Therefore, the inertia compensation control especially during deceleration can be appropriately executed regardless of the situation such as the power supply voltage. As a result, the influence of the inertia of the entire braking means BRK including the inertia of the electric motor MTR can be appropriately compensated.

  BRK ... brake actuator, ECU ... electronic control unit, MTR ... electric motor, BPA ... braking operation amount detection means, SAA ... steering angle detection means, YRA ... yaw rate detection means, GXA ... longitudinal acceleration detection means, GYA ... lateral acceleration detection means , VWA ... wheel speed detection means, FBA ... push force detection means, IMA ... energization amount detection means, position detection means ... MKA

Claims (4)

An operation amount acquisition means for acquiring an operation amount of the braking operation member of the vehicle by the driver;
Braking means for generating braking torque for the wheels of the vehicle by an electric motor;
A control means for calculating a target energization amount based on the operation amount, and controlling the electric motor based on the target energization amount;
A vehicle braking control apparatus comprising:
Comprising an energization amount acquisition means for acquiring an actual energization amount of the electric motor;
The control means includes
Based on the operation amount, it is determined whether or not inertia compensation control for compensating for the influence of inertia of the braking means at the time of acceleration at which the speed of the electric motor is increased,
When it is determined that the inertia compensation control at the time of acceleration is necessary, the first inertia compensation energization amount for increasing the target energization amount to compensate for the influence of the inertia of the braking means is calculated,
Based on the operation amount, it is determined whether or not an inertia compensation control for compensating for the influence of the inertia of the braking means at the time of deceleration at which the speed of the electric motor decreases,
When it is determined that the inertia compensation control at the time of acceleration is necessary, when it is determined that the inertia compensation control at the time of deceleration is necessary, the actual inertia acquired in correspondence with the first inertia compensation energization amount Based on the energization amount, a second inertia compensation energization amount for reducing the target energization amount to compensate for the influence of the inertia of the braking means is calculated,
A braking control device for a vehicle configured to calculate the target energization amount based on the first and second inertia compensation energization amounts. The vehicle braking control device according to claim 1,
The control means includes
Based on the manipulated variable, calculate at least one state equivalent value of acceleration equivalent value and speed equivalent value;
Based on the state equivalent value, of whether the it is necessary to accelerate the inertia compensation control during the determination, and, during the deceleration inertia compensation control during the acceleration is executed if it is determined to be necessary A vehicle braking control apparatus configured to perform at least one of determination of whether inertia compensation control is necessary. In the vehicle brake control device according to claim 1 or 2,
The control means includes
When it is determined that the inertia compensation control at the time of acceleration is necessary, the actual inertia of the electric motor when the first inertia compensation energization amount is step input of the target energization amount to the electric motor. A braking control device for a vehicle, configured to calculate the first inertia compensation energization amount using a time-series pattern set in advance based on a change in position. The vehicle brake control device according to claim 3,
The control means includes
Based on the actual energization amount acquired corresponding to the first inertia compensation energization amount, obtaining time series data corresponding to the time series pattern,
A braking control device for a vehicle configured to calculate the second inertia compensation energization amount based on the time series data when it is determined that the inertia compensation control at the time of deceleration is necessary.

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