JP2007238034A - Brake control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brake control device capable of suppressing the rotor run-out by detecting the rotor run-out with high accuracy. <P>SOLUTION: The brake control device in a disk brake for generating the braking force by pressing a disk rotor with a brake pad comprises a pressing means 8 for pressing the brake pad against a disk rotor, a contact state detection means 5 for detecting the contact state of the brake pad with the disk rotor when a vehicle is traveling, and an estimation means 9 for estimating the run-out state of the disk rotor based on the change in the contact state detected by the contact state detection means 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a brake control device that detects rotor shake and suppresses rotor shake.

The disc brake generates a braking force by sandwiching a disc rotor that rotates together with a wheel from both left and right sides with brake pads and bringing two brake pads into contact with the disc rotor by the operation of a piston. In the case of a disc brake, vibration may occur in the vehicle body and the brake pedal during braking, and this vibration gives the driver an unpleasant feeling. Therefore, various techniques for suppressing vibrations in the disc brake have been developed. As one of the vibration damping technologies, there is one that reduces the difference in thickness of the disk rotor, which is a cause of vibration. For example, the thickness difference of the disk rotor is detected, and the brake pad is brought into contact with a portion with a larger pressing force than a portion where the thickness of the disk rotor is thinner (see Patent Document 1). Thereby, the thick part of the disk rotor is ground, and the thickness difference of the disk rotor is reduced.
JP 2001-130393 A

  Due to the assembling accuracy and the processing accuracy of each member, it is difficult to dispose the disc rotor completely perpendicular to the rotation axis of the wheel, and the disc rotor rotates with slight surface deflection. When the brake pad is pressed in such a state that the disc rotor is shaken, a portion where the disc rotor is pressed strongly and a portion where the disc rotor is pressed weakly occurs during one rotation of the disc rotor, resulting in a thickness difference in the disc rotor. Occurs. As described above, the thickness difference of the disk rotor is a cause of occurrence of rotor runout. Here, the difference in thickness of the disk rotor indicates a difference in thickness in the circumferential direction during one rotation of the disk rotor on the same circumference having a sliding surface.

  As described above, the conventional vibration damping technology aims to reduce the disc rotor thickness difference, and the disc rotor is ground based on the rotor thickness difference. However, even if the thickness difference is reduced, the rotor runout exists, so that the rotor runout again causes a thickness difference in the disk rotor. Therefore, the rotor thickness difference is detected again, and the disk rotor is ground based on the rotor thickness difference. Thus, since the rotor runout that causes the rotor thickness difference continues to exist, the reduction and generation of the rotor thickness difference are repeated, and the vibration during braking can be suppressed only temporarily. Further, since the disk rotor is repeatedly ground to reduce the rotor thickness difference, the life of the disk rotor and brake pads is reduced. Furthermore, since the thickness difference is reduced by dragging between the brake pad and the disk rotor, an extra braking force is generated, and the fuel consumption is also deteriorated.

  Accordingly, an object of the present invention is to provide a brake control device that detects rotor shake with high accuracy and suppresses rotor shake.

  A brake control device according to the present invention is a brake control device in a disc brake that generates a braking force by pressing a disc rotor with a brake pad, a pressing unit that presses the brake pad against the disc rotor, a running brake pad, Contact state detection means for detecting a contact state with the disk rotor, and estimation means for estimating a shake state of the disk rotor based on a change in the contact state detected by the contact state detection means.

  In this brake control device, the brake pad is pressed against the disc rotor by the pressing means, and the braking force is controlled by changing the pressing force. Further, in the brake control device, the contact state detection means detects the contact state between the brake pad and the disc rotor during traveling. The contact state detected by the contact state detection means is information that can directly detect the contact state between the brake pad and the disk rotor, or information that can indirectly estimate the contact state. This is information related to the drag torque between the rotors, the surface pressure of the brake pads, the tire ground contact force, the torque receiving portion load, and the like, and information related to the displacement of indirect members such as pistons, slide pins, and brake pads. When rotor runout exists, the contact state between the brake pad and the disk rotor during one rotation of the rotor during running changes according to the runout state during one rotation of the rotor. Therefore, in the brake control device, the estimation means estimates the shake state of the disk rotor based on the detected change in the contact state. Thus, in this brake control device, the shake state of the disc rotor can be detected with high accuracy from the change in the contact state between the brake pad and the disc rotor. By using this highly accurate rotor runout state, the disc rotor can be prevented from running out by pressing the disc rotor with a brake pad in accordance with the rotor runout state.

  In the above brake control device of the present invention, the brake pad is brought close to the disc rotor with a constant pressing force by the pressing means at the time of stop, and then the contact state is detected by the contact state detecting means at the start, and the contact at the start by the estimating means It is preferable to estimate the runout state of the disk rotor based on the change in the state.

  In this brake control device, when stopped, the brake pad is brought close to the disk rotor with a constant pressing force by the pressing means (including bringing the brake pad into contact with the disk rotor). Thereafter, in the brake control device, the contact state between the brake pad and the disk rotor at the time of start is detected by the contact state detection means. In the brake control device, the estimation means estimates the vibration state of the disc rotor from the change in the contact state at the time of starting. As described above, in the brake control device, the contact state between the brake pad and the disk rotor is stabilized by applying a constant pressing force at the time of stopping, so that the rotor shake state can be estimated with higher accuracy.

  In the brake control device according to the present invention, the brake pad is applied to the disc rotor by the pressing means that causes the deceleration of the vehicle body to be equal to or less than a predetermined deceleration by the pressing means according to the swing state of the disc rotor estimated by the estimating means during non-braking. Press.

  In this brake control device, during non-braking, the pressing means presses the brake pad against the disc rotor with a pressing force that causes the deceleration of the vehicle body to be equal to or less than a predetermined deceleration according to the estimated shake state. In this pressing, the pressing force is increased in the portion where the deflection is large, and the disk rotor is ground. Thus, in the brake control device, the disc rotor can be prevented from swinging due to a small pad-rotor drag torque caused by a small pressing force at which the deceleration of the vehicle body is equal to or less than a predetermined deceleration. As a result, the occurrence of the disc rotor thickness difference can be suppressed as much as possible, and the durability and fuel consumption of the disc rotor and brake pads can be improved. The predetermined deceleration is a deceleration that does not make the passenger feel uncomfortable or a deceleration that does not excessively decelerate the vehicle.

  The brake control device according to the present invention may be configured to give priority to the disc rotor shake suppression control over the disc rotor circumferential thickness difference suppression control.

  In this brake control device, the thickness difference suppression control in the circumferential direction of the disk rotor and the vibration suppression control of the disk rotor are performed, and the disk rotor vibration suppression control is preferentially performed during non-braking. As a result, the disc rotor runout, which is a cause of the rotor thickness difference, is preferentially suppressed, and the rotor thickness difference can also be suppressed by suppressing the rotor shake.

  According to the present invention, rotor shake can be detected with high accuracy, and rotor shake can be suppressed by performing braking control based on the detected rotor shake.

  Hereinafter, an embodiment of a brake control device according to the present invention will be described with reference to the drawings.

  In the present embodiment, the brake control device according to the present invention is applied to a brake control device provided in a disc brake device mounted on a vehicle. The brake control device according to the present embodiment assists the driver's brake operation with the control brake. Furthermore, the brake control device according to the present embodiment suppresses the disc rotor deflection and the circumferential thickness difference by the control brake.

  As the disc brake according to the present embodiment, various types of disc brakes such as a floating caliper type and an opposed piston type can be applied. The disc brake is provided with a disc rotor DR that rotates together with the wheels, and the caliper is provided with a pair of brake pads BP and BP across the disc rotor DR (see FIG. 2). A wheel cylinder is formed in the caliper, and a piston is slidably provided along the tangential direction of the disk rotor. In the brake control device according to the present embodiment, the hydraulic pressure of the wheel cylinder is changed by the brake actuator to control the pressing force of the piston (brake pad).

  As shown in FIG. 2, the disc brake DR has runout F due to the assembly accuracy and the like. This shake F periodically changes during one rotation of the rotor, and one or more shake peaks FP exist as shown in FIG. This fluctuation peak FP occurs in the same way on the IN side and OUT side with a phase shift during one rotation of the rotor. In the brake control device according to the present embodiment, the period and peak of the runout are estimated, and a large portion of runout of the disc rotor DR is ground by the brake pad according to the estimated runout period and peak (see FIG. 3). ). When estimating the shake, it is only necessary to estimate the shake on at least one side of the IN side and the OUT side.

  Further, as shown in FIG. 4, a thickness difference N occurs in the circumferential direction in the disk rotor DR due to rotor runout. This thickness difference N also changes periodically during one rotation of the wheel, and there are one or more peaks. In the brake control device according to the present embodiment, the period and peak of the wall thickness difference are estimated, and a portion where the disk rotor has a large wall thickness difference is ground with a brake pad according to the estimated wall thickness difference period and peak. To do. When estimating the wall thickness difference, both sides of the IN side and the OUT side are detected, and the wall thickness difference is estimated from the difference between the both sides.

  A brake control device 1 according to the present embodiment will be described with reference to FIGS. 1, 5, and 6. FIG. 1 is a configuration diagram of a brake control device according to the present embodiment. FIG. 5 is a time chart at the time of non-braking according to the present embodiment, where (a) is a temporal change in pad temperature, (b) is a temporal change in wheel speed, and (c) is a vehicle speed time. (D) is the ON / OFF of the pressurization request for shake / thickness difference reduction, (e) is the time change of the hydraulic pressure of the wheel cylinder, and (f) is the pad / rotor contact state detection amount. (G) is a time change of the estimated rotor runout, and (h) is a time change of the estimated rotor thickness difference. FIG. 6 is a time chart at the time of braking according to the present embodiment, where (a) is a temporal change in pad temperature, (b) is a temporal change in wheel speed, and (c) is a temporal change in vehicle speed. (D) is ON / OFF of the pressure request for vibration / thickness difference reduction, (e) is the time change of the hydraulic pressure of the wheel cylinder, (f) is the time change of the braking force, (G) is the time change of the estimated rotor thickness difference.

When the driver performs a brake operation, the brake control device 1 sets a target pressing force based on the stroke of the brake pedal, and generates a braking force according to the brake operation by the control brake. In particular, the brake control device 1 estimates the runout of the disk rotor and the thickness difference in the circumferential direction, sets a target pressing force according to the estimated runout or thickness difference, and controls the runout or thickness difference by the control brake. To reduce. For this purpose, the brake control device 1 includes a brake pedal sensor 2, a wheel speed sensor 3, a pad temperature sensor 4, a drag torque sensor 5, a braking torque sensor 6, a longitudinal acceleration sensor 7, a brake actuator 8, and an ECU [Electronic Control Unit] 9. It has. In the present embodiment, the drag torque sensor 5 corresponds to the contact state detection means described in the claims, and the brake actuator 8 corresponds to the pressing means described in the claims.
The brake pedal sensor 2 is a sensor that detects a stroke amount (brake operation amount) of the brake pedal. The brake pedal sensor 2 transmits the detected stroke amount to the ECU 9 as a brake signal.

  The wheel speed sensor 3 is a sensor that is provided in each wheel and detects the rotational speed of the wheel. The wheel speed sensor 3 transmits the detected rotation speed to the ECU 9 as a wheel speed signal.

  The pad temperature sensor 4 is a sensor that is provided in each wheel and detects the temperature of the brake pad. The pad temperature sensor 4 transmits the detected pad temperature to the ECU 9 as a pad temperature signal.

  The drag torque sensor 5 is a sensor that is provided in each wheel and detects drag torque between the disc rotor and the brake pad. The drag torque sensor 5 transmits the detected drag torque to the ECU 9 as a drag torque signal.

  The braking torque sensor 6 is a sensor that is provided in each wheel and detects braking torque. The braking torque sensor 6 transmits the detected braking torque to the ECU 9 as a braking torque signal.

  The longitudinal acceleration sensor 7 is a sensor that detects the longitudinal acceleration of the vehicle. The longitudinal acceleration sensor 7 transmits the detected longitudinal acceleration to the ECU 9 as a longitudinal acceleration signal.

  The brake actuator 8 is an actuator that is provided on each wheel and controls the hydraulic pressure of the wheel cylinder, and changes the pressing force of the piston. In the brake actuator 8, the actuator is operated according to the control current from the ECU 9, and a predetermined hydraulic pressure is generated in the wheel cylinder to pressurize it.

  The ECU 9 includes a CPU [Central Processing Unit], a ROM [Read Only Memory], a RAM [Random Access Memory], and the like, and is an electronic control unit. The ECU 9 receives detection signals from the sensors 2-7. Then, the ECU 9 controls the brake actuator 8 of each wheel by performing a rotor shake specifying process, a rotor thickness difference specifying process, a target calculation process, an actuator control process, and the like. In the present embodiment, the processing in the ECU 9 corresponds to the estimation means described in the claims.

In ECU 9, the pad temperature is performed only rotor runout identification process and the rotor thickness difference identification processing when the range of the detection execution upper limit temperature theta _sth and the detection carried lower limit temperature theta _stl (see Figure 5 (a)). As described above, the reason why only the brake-related temperature is within the specified range (normal temperature) is to improve the estimation accuracy of the rotor runout and the rotor thickness difference by reducing the influence of the thermal deformation of the disk rotor. . Detection carried minimum temperature theta _stl, detection execution upper limit temperature theta _sth is lower limit temperature and the upper limit temperature indicating an ambient temperature range.

The rotor runout specifying process will be described. In order to improve the specific accuracy, the rotor shake is detected by detecting a contact state between the brake pad and the disk rotor when the vehicle starts after applying a certain pressing force while the vehicle is stopped. The ECU 9 determines whether or not to stop the vehicle depending on whether the vehicle speed is lower than the stop determination prescribed vehicle speed V _smin and the driver's braking request (the amount of pressurization of the wheel cylinder in accordance with the required braking force) is greater than the stop determination required oil pressure P _smin. (See FIGS. 5C and 5E). The specified vehicle speed for stop determination V _smin is an extremely low vehicle speed for determining the vehicle stop state. The stop determination required oil pressure P _smin is the amount of pressurization of the wheel cylinder in accordance with the braking request that the driver performs at the minimum when the vehicle is stopped. Regarding the vehicle speed used for the determination, the ECU 9 estimates the vehicle speed from the wheel speed of each wheel.

When the vehicle is stopped, the ECU 9 _turns on the pressure request for shake / thickness difference reduction and sets P _saim as the target pressurization amount P _aim (target pressing force) (FIGS. _5D and _5E ). reference). Then, the ECU 9 sets a target current for operating the brake actuator 8 so that the target pressurization amount P _aim = P _saim, and outputs a control current to the brake actuator 8 of each wheel so as to be the target current. . As a result, the wheel cylinder is pressurized to P _saim while the vehicle is stopped, and a constant pressing force is generated. P _saim is a pressurization amount for keeping the pressing force (and thus the braking force related amount) constant when detecting the contact state in order to stabilize the contact state between the pad and the rotor.

After starting the stop pressurization, the ECU 9 counts the stop pressurization execution time. Then, the ECU 9 determines the end of stop pressurization depending on whether the stop pressurization execution time is longer than the stop pressurization prescribed time _Tsp or the pressurization request by the driver is turned on (see FIG. 5 (e)). . The stop pressurization prescribed time _Tsp is a time necessary for _achieving a stable contact state. ON / OFF of a pressurization request | requirement is detected from accelerator pedal operation, for example. When the stop pressurization is finished, the ECU 9 turns off the shake / wall thickness difference pressurization request and sets the target pressurization amount P _aim to 0 (see FIGS. 5D and 5E). Then, the ECU 9 outputs a control current to the brake actuator 8 of each wheel so that the target pressurization amount P _aim = 0 as in the above case. Thereby, the pressurization while the vehicle is stopped is completed.

After the stop pressurization is completed, the ECU 9 determines the start of the vehicle depending on whether the vehicle speed is higher than the lower limit vehicle speed V _fs for shake / thickness difference detection start determination (see FIG. 5C). The lower limit vehicle speed V _fs for determination of shake / thickness difference detection start is a vehicle speed for reliably determining that the vehicle has started. When the vehicle starts, the ECU 9 calculates the rotation period of the wheel from the wheel speed for each wheel. Then, the ECU 9 detects the contact state between the pad and the rotor by the drag torque between the pad and the rotor for each wheel (see FIG. 5F). The greater the rotor runout, the closer the disc rotor is to the brake pad and the stronger the brake pad and disc rotor are in contact, so the drag torque increases. Further, due to the rotor runout, the drag torque fluctuation appears as a similar fluctuation in a state where the phase is shifted between the IN side and the OUT side. Therefore, the fluctuation of the rotor torque during one rotation of the rotor can be determined from the fluctuation of the drag torque during one rotation of the rotor. For each wheel, the ECU 9 monitors drag torque fluctuations in association with the wheel rotation cycle, and extracts each peak (magnitude and phase in one rotation cycle) of the rotor side of the IN side and OUT side (FIG. 5 ( f)). If there are multiple peaks, collect data for multiple peaks. Then, the ECU 9 repeatedly extracts the peak data with respect to the rotation of the wheel, and specifies the peak period and magnitude (that is, the rotor shake period and peak) for each peak based on the collected data. (See FIG. 5 (g)).

  The rotor thickness difference specifying process will be described. There are two methods for identifying the rotor wall thickness difference. One method is to identify the contact state between the pad and the rotor when the rotor runout is identified, and the other method is based on fluctuations in braking force during braking. It is a method to specify.

  As the thickness difference increases, the portion of the disc rotor approaches the brake pad, and the brake pad and the disc rotor come into strong contact with each other, so that drag torque increases. Further, since the rotor thickness difference is random between the IN side and the OUT side, drag torque appears as individual fluctuations between the IN side and the OUT side. Therefore, the state of the rotor thickness difference during one rotation of the rotor can be determined from the fluctuation of the drag torque during one rotation of the rotor.

  When the rotor runout is specified, the ECU 9 monitors the drag torque fluctuation for each wheel in association with the rotation period of the wheel, and each peak on the IN side and OUT side of the rotor wall thickness difference (in magnitude and one rotation period). Phase) (see FIG. 5F). If there are multiple peaks, collect data for multiple peaks. Then, the ECU 9 repeatedly extracts the peak data with respect to the rotation of the wheel, and based on the collected data, the peak period and magnitude (that is, the rotor meat) from the difference between the IN side and the OUT side of each peak. The thickness difference period and peak are specified (see FIG. 5H).

Further, the ECU 9 determines _whether the vehicle is braking _depending on _{whether the} vehicle speed is higher than the specified vehicle speed _Vdaim for determination during braking and _{whether the} driver's braking request (the amount of pressurization of the wheel cylinder) is greater than the required hydraulic pressure for determination _Pdam during braking. . The prescribed vehicle speed _Vdaim for determination during braking is a vehicle speed for determining the vehicle running state. Requested hydraulic P _DAIM for determining during braking is pressurization of the wheel cylinder can be seen is ensured that there is a braking request by the driver when the vehicle running state.

  When braking, the ECU 9 calculates the rotation period of the wheel from the wheel speed for each wheel. The ECU 9 detects a braking torque (braking force) during braking for each wheel. As the rotor thickness difference is larger, the portion of the disc rotor is closer to the brake pad, and the disc rotor and the brake pad are in strong contact with each other, so that the braking torque is increased. Therefore, the rotor thickness difference during one rotation of the rotor can be determined from the fluctuation of the braking torque during one rotation of the rotor. For each wheel, the ECU 9 monitors the fluctuation of the braking torque in association with the rotation period of the wheel, and extracts each peak (magnitude and phase in one rotation period) of the rotor wall thickness difference on the IN side and OUT side (FIG. 6 (g)). If there are multiple peaks, collect data for multiple peaks. Then, the ECU 9 repeatedly extracts the peak data with respect to the rotation of the wheel, and based on the collected data, the peak period and magnitude (in other words, the rotor) from the difference between the IN side and the OUT side of each peak. The wall thickness difference cycle and peak) are specified (see FIG. 6G).

The target calculation process will be described. The calculation of the target pressing force (target pressurization amount P _aim ) is performed separately during braking and during non-braking. The ECU 9 performs the braking determination by the same determination as described above. When braking, the target pressing force is determined based on the braking force requested by the driver. When the rotor thickness difference is specified, the target pressing force is determined by taking the thickness difference into consideration. In the case of non-braking, the target pressing force is normally 0 because there is no braking force requested by the driver. However, when the rotor runout and the rotor thickness difference are specified, the target is based on the runout or thickness difference. Find the pressing force. Basically, the target pressing force is obtained by giving priority to the rotor runout that causes the rotor thickness difference. However, if the rotor thickness difference is larger than the specified value, the vibration due to the thickness difference will increase. The target pressing force is obtained giving priority to the thickness difference.

In the case of braking, the ECU 9 determines whether or not the peak value of the rotor thickness difference is larger than the rotor thickness difference reduction target D _aim . The rotor thickness difference reduction target D _aim is a lower limit value of the peak of the wall thickness difference for determining whether or not the rotor wall thickness difference needs to be reduced. When it is necessary to reduce the rotor thickness difference, the ECU 9 calculates the wheel rotation cycle from the wheel speed, and calculates the braking force fluctuation for each rotation cycle. The fluctuation of the braking force for each rotation cycle is controlled during the rotation of the rotor due to a rotor thickness difference or the like when a constant pressing force (a constant amount of pressure applied to a wheel cylinder) is applied by the driver's requested braking force. This is a fluctuation in power (see FIGS. 6E and 6F). Then, the ECU 9 determines whether or not the braking force fluctuation is smaller than the braking force fluctuation upper limit ΔT _limit . The braking force fluctuation upper limit ΔT _limit is an upper limit value of the braking force fluctuation capable of varying the pressing force for reducing the rotor thickness difference.

In the case of a braking force fluctuation capable of changing the pressing force for reducing the rotor thickness difference, the average pressing force of the pressing force fluctuation during one rotation of the rotor for reducing the rotor thickness difference is determined according to the required braking force. The target pressing force is set so that the braking force fluctuation during one rotation of the rotor becomes a specified value or less. Therefore, in the ECU 9, the braking force fluctuation when the pressing force is changed during one rotation of the rotor is (the braking force fluctuation upper limit ΔT _{limit -the} braking force fluctuation during one rotation of the rotor when a constant pressing force is applied). Thus, the fluctuation of the pressing force during one rotation of the rotor is obtained. Then, the ECU 9 obtains the target pressing force (target pressurization amount P _aim ) by adding the rotor thickness difference to the required braking force by the driver based on the obtained pressing force fluctuation during one rotation of the rotor. At this time, the phase is adjusted so that the maximum value of the target pressing force is reached at the peak portion of the rotor thickness difference (the portion where the thickness difference is thick), and the maximum value of the target pressing force is determined according to the peak value of the rotor thickness difference. Set.

  When the target pressing force is determined, the ECU 9 turns on the shake / thickness difference reduction request (see FIG. 6D). Then, the ECU 9 determines the control start timing so that the peak period of the rotor thickness difference coincides with the peak period of the target pressing force in consideration of sensing and the delay of the actuator system (FIGS. 6E and 6G). reference). In accordance with this target pressing force and the control start timing, after the control is started, the amount of pressurization of the wheel cylinder generates a braking force that takes into account the braking force fluctuation for reducing the rotor thickness difference to the driver's required braking force. (See FIGS. 6E and 6F).

When it is not necessary to reduce the rotor thickness difference or when the braking force fluctuation is large and the pressing force fluctuation for reducing the rotor thickness difference is not possible, the ECU 9 sets the target pressing force according to the braking force requested by the driver ( The target pressurization amount P _aim ) is obtained.

When not braking, the ECU 9 determines whether or not the peak value of the rotor wall pressure difference is larger than the rotor wall thickness difference reduction upper limit target D _limit . The rotor thickness difference reduction upper limit target D _limit is a target value on the upper limit side of the peak of the wall thickness difference for determining whether or not it is necessary to suppress brake vibration with priority, and the rotor wall thickness difference reduction target It is a value larger than D _aim .

When the rotor thickness difference is larger than the rotor thickness difference reduction upper limit target D _limit and it is necessary to suppress brake vibration, and priority is given to reducing the rotor thickness difference, the ECU 9 determines the rotor according to the peak value of the rotor thickness difference. The maximum value of the target pressing force during one rotation is set, and the minimum value is set to zero. Further, the ECU 9 calculates the rotation cycle of the wheel from the wheel speed for each wheel. Then, the ECU 9 obtains the target pressing force for each wheel based on the waveform (variation) of the rotor thickness difference. At this time, the phase is adjusted so that the maximum value of the target pressing force is obtained at the peak portion of the rotor thickness difference. Further, the ECU 9 calculates how long a period (travel distance) is necessary for the rotor thickness difference reduction to be less than or equal to the rotor thickness difference reduction upper limit target D _limit when the rotor thickness difference is reduced by the obtained target pressing force.

  When the target pressing force is obtained, the ECU 9 turns on the shake / thickness difference reduction request. Then, the ECU 9 determines the control start timing in the same manner as described above. By the target pressing force and the control start timing, the pressurization amount of the wheel cylinder becomes the pressurization amount for generating the braking force fluctuation for reducing the rotor thickness difference after the control is started.

When the rotor thickness difference is within the rotor thickness difference reduction upper limit target D _limit and it is not necessary to prioritize the rotor thickness difference reduction (see FIG. 5 (h)), the ECU 9 determines that the peak value of the rotor runout is the rotor runout. It is determined whether or not it is larger than the reduction target L _aim . The rotor shake reduction target L _aim is a lower limit value of the peak of rotor shake for determining whether or not the rotor shake needs to be reduced. When it is not necessary to reduce the rotor runout, it is determined again whether or not to reduce the rotor thickness difference. Specifically, the ECU 9 determines whether or not the peak value of the rotor thickness difference is larger than the rotor thickness difference reduction target D _aim, and if it is necessary to reduce the rotor thickness difference, the same as above is performed. Based on the rotor thickness difference, the target pressing force and the control start timing are obtained by processing.

When the rotor runout is larger than the rotor runout reduction target _{Laim and} it is necessary to reduce the rotor runout (see FIG. 5G), the rotor runout reduction that causes the rotor thickness difference is preferentially performed. Therefore, the ECU 9 sets the maximum value of the target pressing force during one rotation of the rotor from the peak value of the rotor shake, and sets the minimum value to zero. Further, the ECU 9 calculates the rotation cycle of the wheel from the wheel speed for each wheel. Then, the ECU 9 obtains the target pressing force for each wheel based on the rotor shake waveform (variation). At this time, the phase is adjusted so that the maximum value of the target pressing force is obtained at the peak portion of the rotor runout. Further, the ECU 9 calculates how much time (travel distance) is required for the rotor shake reduction to be equal to or less than the rotor shake reduction target L _aim when the rotor shake reduction is performed with the obtained target pressing force.

  When the target pressing force is obtained, the ECU 9 turns on the shake / thickness difference reduction request (see FIG. 5D). Then, the ECU 9 determines the control start timing in the same manner as described above. By the target pressing force and the control start timing, the pressurization amount of the wheel cylinder becomes the pressurization amount for generating the braking force fluctuation for reducing the rotor shake after the control is started (see FIG. 5E). .

  Note that, during non-braking, the target pressing force is set to such a small pressing force that the deceleration of the vehicle body is not more than a predetermined deceleration. The predetermined deceleration is a deceleration that does not cause the passenger to feel uncomfortable or excessively decelerate the vehicle.

  The actuator control process will be described. In the actuator control process, actuator control differs between braking (when a driver's braking request is present) and non-braking (when there is no driver's braking request). During braking, actuator control is performed according to the driver's required braking force.If the rotor thickness difference is greater than the specified value, actuator control that takes into account fluctuations in the braking force to reduce the rotor thickness difference is performed. Do. Actuator control is not normally performed during non-braking, but if the rotor runout or rotor thickness difference is greater than the specified value, actuator control according to braking force fluctuations to reduce rotor runout or rotor thickness difference I do.

During braking, the ECU 9 sets a target current for operating the brake actuator 8 so that the target pressurization amount P _aim (target pressing force) for braking is set, and the target current is supplied to the brake actuator 8 of each wheel. The control current is output so that During this control, the ECU 9 determines whether or not the braking request by the driver (the amount of pressurization of the wheel cylinder in accordance with the required braking force) has become smaller than the brake OFF determination lower limit hydraulic pressure _Pblimit , and the brake OFF determination lower limit. The actuator control is continued until the hydraulic pressure P _limit becomes smaller (see FIG. _6E ). Braking OFF determination lower limit pressure P _bLimit is braking request of the driver is reduced, an amount of pressurization of the wheel cylinder for determining whether may end the braking control.

In the case of non-braking, the ECU 9 determines whether or not the target pressurization amount P _aim (target pressing force) is 0. If it is 0, the actuator control is not performed. When the target pressurization amount P _aim (target pressing force) is not 0 (that is, when the target pressing force for reducing the runout or thickness difference of the rotor is set), the ECU 9 uses the pad temperature for fading suppression. It is determined whether the temperature is lower than the upper limit temperature θ _fth . The upper limit temperature for fade suppression θ _fth is an upper limit temperature for suppressing the increase in the rotor temperature due to the drag torque between the pad and the rotor during non-braking and ensuring the fade performance.

When the pad temperature is lower than the fade suppression upper limit temperature θ _fth (see FIG. 5A), the ECU 9 _controls the brake actuator 8 so that the target pressurization amount P _aim (target pressing force) for non-braking is obtained. A target current to be operated is set, and a control current is output to the brake actuator 8 of each wheel so as to be the target current. During this control, the ECU 9 determines whether the longitudinal acceleration of the vehicle is greater than the non-braking coasting upper limit deceleration G _limit . The non-braking coasting upper limit deceleration G _limit is an upper limit value of the deceleration for reducing the maximum value of the target pressing force in order to reduce the deterioration of fuel consumption due to the drag torque between the pad and the rotor during non-braking. .

While the longitudinal acceleration of the vehicle is greater than the non-braking coasting upper limit deceleration G _limit , the ECU 9 continues the actuator control and reduces the maximum value of the target pressing force at that time. Specifically, the current maximum value of the target pressing force × G _limit / the current longitudinal acceleration is set as the maximum value of the next target pressing force (target pressurization amount P _aim ). When the longitudinal acceleration becomes equal to or less than the coasting upper limit deceleration G _limit during non-braking, the ECU 9 stops the actuator control during non-braking.

  Next, the operation of the brake control device 1 will be described with reference to FIG. In particular, the main process in the ECU 9 will be described with reference to the flowchart of FIG. 7, the rotor runout specifying process will be described with reference to the flowchart of FIG. 8, and the rotor thickness difference specifying process will be described with reference to the flowchart of FIG. The target calculation process will be described with reference to the flowcharts of FIGS. 10 and 11, and the actuator control process will be described with reference to the flowchart of FIG. In the brake control device 1, the following operation is repeatedly executed at regular intervals.

  The brake pedal sensor 2 detects the stroke amount of the brake pedal and transmits a brake signal to the ECU 9. Each wheel speed sensor 3 detects the rotational speed of the wheel and transmits a wheel speed signal to the ECU 9. Each pad temperature sensor 4 detects the temperature of the brake pad and transmits a pad temperature signal to the ECU 9. Each drag torque sensor 5 detects a drag torque between the pad and the rotor and transmits a drag torque signal to the ECU 9. Each braking torque sensor 6 detects a braking torque and transmits a braking torque signal to the ECU 9. The longitudinal acceleration sensor 7 detects longitudinal acceleration and transmits a longitudinal acceleration signal to the ECU 9.

In ECU 9, it determines whether the pad temperature is lower than the high and the detection execution upper limit temperature theta _sth than detection exemplary limit temperature θ _stl (S1). Only when the determination condition of S1 is satisfied, the ECU 9 executes the rotor runout specifying process (S2) and the rotor thickness difference specifying process (S3). When the target calculation process (S4) is performed when the rotor runout specifying process (S2) and the rotor thickness difference specifying process (S3) are not executed, the rotor runout period and peak and the rotor thickness difference period and peak When a value has already been specified, the most recently specified value is used.

When executing the rotor shake identification process, first, the ECU 9 determines whether the vehicle speed is lower than the stop determination specified vehicle speed V _smin and whether the wheel cylinder pressurization amount in response to the braking request is greater than the stop determination request hydraulic pressure P _smin. (S10). When the determination condition of S10 is not satisfied (that is, when the vehicle is running), the process proceeds to S21 of the rotor thickness difference specifying process.

When the determination condition of S10 is satisfied (that is, when the vehicle is stopped), the ECU 9 turns ON the pressurization request for shake / thickness difference reduction. Then, the ECU 9, the target pressurizing sets the _{P Saim} the pressure amount _{P aim,} so that the target pressure application amount _{P aim} outputs a control current to the brake actuator 8 of each wheel (S11). Then, the brake actuator 8 of each wheel operates according to the control current, and changes the pressurization amount of the wheel cylinder so as to become the target pressurization amount P _aim . As a result, the wheel cylinder is pressurized while the vehicle is stopped, and the piston (brake pad) has a constant pressing force. When the pressing force becomes constant, the ECU 9 counts the stop pressurization execution time (S12). Further, the ECU 9 determines whether the stop pressurization execution time is longer than the stop pressurization prescribed time _Tsp or whether the pressurization request by the driver is turned on (S13). If the determination condition of S13 is not satisfied, the ECU 9 returns to the process of S11 and continues the stop pressurization.

When the determination condition of S13 is satisfied, the ECU 9 sets the target pressurization amount P _aim to 0, and stops the output of the control current to the brake actuator 8 of each wheel (S14). Then, the brake actuator 8 of each wheel stops operating, and pressurization stops. Subsequently, the ECU 9 determines whether or not the vehicle speed has become higher than the shake / thickness difference detection start lower limit vehicle speed _Vfs (S15). When the determination condition of S15 is not satisfied, the ECU 9 returns to the process of S14.

  When the determination condition of S15 is satisfied (that is, when the vehicle has started), the ECU 9 specifies the rotation period of the wheel from the wheel speed for each wheel (S16), and the pad rotor by the drag torque between the pad and rotor. A contact state between them is detected (S17). Then, the ECU 9 specifies the rotor run-out period and peak from the fluctuation of the drag torque in association with the wheel rotation period for each wheel (S18).

  When the rotor thickness difference specifying process is executed, when the contact state between the pad and the rotor (the drag torque) is detected in the rotor runout specifying process, the ECU 9 drags each wheel in association with the rotation period of the wheel. The period and peak of the rotor thickness difference are specified from the torque variation (S20).

If it is determined in S10 that the vehicle is traveling, the ECU 9 determines that the vehicle speed is higher than the specified vehicle speed _Vdaim for determination during braking and the pressurization amount of the wheel cylinder according to the braking request is determined from the required hydraulic pressure _Pdaim for determination during braking. It is determined whether it is larger (S21). If the determination condition of S21 is not satisfied, the ECU 9 returns to the process of S1.

  When the determination condition of S21 is satisfied (that is, when the vehicle is being braked), the ECU 9 specifies the rotation period of the wheel from the wheel speed for each wheel (S22) and detects braking force related information from the braking torque ( S23). Then, the ECU 9 identifies the period and peak of the rotor thickness difference from the fluctuation of the braking torque in association with the rotation period of the wheel for each wheel (S24).

When the rotor thickness difference specifying process (S2) is completed or the determination condition of S1 is not satisfied, the target calculation process (S3) is executed. The ECU 9 determines whether or not the vehicle speed is higher than the specified vehicle speed _Vdaim for determination during braking and the pressurization amount of the wheel cylinder according to the braking request is larger than the required hydraulic pressure _Pdaim for determination during braking (S30). When the determination condition of S30 is not satisfied (that is, when non-braking is being performed), the ECU 9 proceeds to the process of S40.

When the determination condition of S30 is satisfied (that is, during braking), the ECU 9 determines whether or not the rotor thickness difference is larger than the rotor thickness difference reduction target D _aim (S31). When the determination condition of S31 is satisfied (that is, when it is necessary to reduce the rotor thickness difference), the ECU 9 specifies the rotation period of the wheel from the wheel speed (S32), and at a constant pressing force due to a braking request. The braking force fluctuation for each rotation period is detected (S33). Then, the ECU 9 determines whether or not the detected braking force fluctuation is smaller than the braking force fluctuation upper limit ΔT _limit (S34).

When the determination condition of S34 is satisfied, the ECU 9 causes the braking force fluctuation when the pressing force is changed during one rotation of the rotor to reduce the rotor wall thickness difference (braking force fluctuation upper limit ΔT _{limit −control at a} constant pressing force). The fluctuation of the pressing force for reducing the rotor thickness difference is determined so as to be (power fluctuation) (S35). Then, the ECU 9 adds the rotor thickness difference to the required braking force by the driver so that the phase of the peak of the rotor thickness difference matches the maximum target pressing force value based on the determined pressing force fluctuation. The pressing force (target pressurization amount P _aim ) is determined (S36). Further, the ECU 9 determines the control start timing so that the peak period of the rotor thickness difference matches the peak period of the target pressing force in consideration of sensing and actuator system delay (S37).

On the other hand, when the determination condition of S31 is not satisfied or when the determination condition of S34 is not satisfied (that is, when the rotor thickness difference is not reduced), the ECU 9 sets the target pressing force (based on the driver's required braking force ( The target pressurization amount P _aim is determined (S38).

When the determination condition of S30 is not satisfied (that is, during non-braking), the ECU 9 determines whether or not the rotor wall pressure difference is larger than the rotor wall thickness difference reduction upper limit target D _limit (S40). When the determination condition of S40 is not satisfied (that is, when the rotor thickness difference is not so large as to give priority to the rotor thickness difference), the ECU 9 determines whether or not the rotor shake is larger than the rotor shake reduction target L _aim ( S41). When the determination condition of S41 is not satisfied (that is, when it is not necessary to reduce the rotor runout), the ECU 9 determines whether or not the rotor thickness difference is larger than the rotor thickness difference reduction target D _aim (S42). When the determination condition of S42 is not satisfied (that is, when it is not necessary to reduce the rotor thickness difference), the ECU 9 returns to the process of S1.

  When the determination condition of S40 is satisfied (that is, when the rotor thickness difference is large enough to give priority to the rotor thickness difference) or when the determination condition of S42 is satisfied (that is, when the rotor thickness difference needs to be reduced), The ECU 9 sets the maximum value of the target pressing force during one rotation of the rotor from the peak of the rotor thickness difference, and sets the minimum value to 0 (S43). Further, the ECU 9 specifies the rotation cycle of the wheel from the wheel speed for each wheel (S44). Then, the ECU 9 determines the target pressing force from the rotor thickness difference waveform so that the phase of the rotor thickness difference peak matches the target pressing force maximum value for each wheel (S45). Further, the ECU 9 determines the control start timing so that the peak period of the rotor thickness difference matches the peak period of the target pressing force in consideration of sensing and actuator system delay (S46).

  When the determination condition of S41 is satisfied (when it is necessary to reduce the rotor shake), the ECU 9 sets the maximum value of the target pressing force during one rotation of the rotor from the peak of the rotor shake and sets the minimum value to 0 ( S47). In addition, the ECU 9 identifies the rotation cycle of the wheel from the wheel speed for each wheel (S48). Then, the ECU 9 determines the target pressing force from the rotor deflection waveform so that the phase of the rotor deflection peak and the target pressing force maximum value are matched for each wheel (S49). Further, the ECU 9 determines the control start timing so that the peak period of the rotor deflection matches the peak period of the target pressing force in consideration of sensing and the delay of the actuator system (S50).

When the target calculation process (S4) ends, an actuator control process (S5) is executed. During braking, actuator control is started at the control start timing, and the ECU 9 sets a target current for operating the brake actuator 8 so that the target pressurization amount P _aim (target pressing force) for braking is reached. Then, the control current is output to the brake actuator 8 of each wheel so as to be the target current (S60).

Then, the brake actuator 9 operates according to the control current, and changes the pressurization amount of the wheel cylinder so as to become the target pressurization amount P _aim . When reducing the rotor thickness difference, the pressure applied to the wheel cylinder is a constant pressure corresponding to the required braking force and the pressure applied with the fluctuation of the braking force to reduce the rotor thickness difference. Press the brake pads while moving. As a result, the pressing force of the brake pad to the disc rotor changes so as to match the change in the rotor thickness difference in one rotation of the rotor (the pressing force increases as the thickness difference increases). Grind. Also, the required braking force is generated. On the other hand, when the rotor wall thickness difference is not reduced, the pressure applied to the wheel cylinder is a constant pressure corresponding to the required braking force, and the brake pressure is pressed while the piston pressure is constant. As a result, a required braking force is generated.

During this actuator control, the ECU 9 determines whether or not the driver's braking request has become smaller than the braking OFF determination lower limit hydraulic pressure _Pblimit (S61). When the determination condition of S61 is satisfied, the ECU 9 ends the actuator control and returns to the process of S1. On the other hand, when the determination condition of S61 is not satisfied, the ECU 9 returns to the process of S60 and continues the actuator control.

In the case of non-braking, the ECU 9 determines whether or not the non-braking target pressurization amount P _aim (target pressing force) is 0 (S62). When the determination condition of S62 is satisfied (when the rotor runout and the rotor thickness difference are not reduced), the ECU 9 returns to the process of S1. When the determination condition of S62 is not satisfied (that is, when the rotor runout or the rotor thickness difference is reduced), the ECU 9 determines whether the pad temperature is lower than the fade suppression upper limit temperature θ _fth (S63). When the determination condition of S63 is not satisfied (that is, when the fade performance cannot be ensured), the ECU 9 returns to the process of S1 without performing actuator control.

When the determination condition of S63 is satisfied (that is, when fading performance can be ensured), the actuator control is started at the control start timing, and the ECU 9 sets the target pressurization amount P _aim (target pressing force) for braking. Then, a target current for operating the brake actuator 8 is set, and a control current is output to the brake actuator 8 of each wheel so as to be the target current (S64).

Then, the brake actuator 9 operates according to the control current, and changes the pressurization amount of the wheel cylinder so as to become the target pressurization amount P _aim . When the rotor thickness difference is reduced, the pressure applied to the wheel cylinders is a variable pressure for reducing the rotor thickness difference, and the brake pad is pressed while the piston pressure changes. As a result, the pressing force of the brake pad to the disc rotor changes so as to match the change in the rotor thickness difference in one rotation of the rotor (the pressing force increases as the thickness difference increases). Grind. On the other hand, when the rotor runout is reduced, pressurization to the wheel cylinder is fluctuating pressurization for reducing the rotor runout, and the brake pad is pressed while the piston pressurization varies. As a result, the pressing force applied to the disc rotor by the brake pad changes so as to match the change in rotor runout during one rotation of the rotor (the press force increases as the runout increases), and the portion where the disc rotor shakes greatly is ground. .

During this actuator control, the ECU 9 determines whether or not the longitudinal acceleration of the vehicle is greater than the non-braking coasting upper limit deceleration G _limit (S65). When the determination condition of S65 is satisfied, the ECU 9 sets the maximum value of the target pressing force with the current target pressing force maximum value × G _limit / the current longitudinal acceleration as the next target pressing force maximum value (target pressing amount P _aim ). The value is reduced, and the process returns to S64 to continue the actuator control (S66). On the other hand, when the determination condition of S65 is not satisfied, the ECU 9 ends the actuator control and returns to the process of S1.

  According to the brake control device 1, it is possible to estimate the rotor runout with high accuracy based on the change in the contact state between the pad and the rotor, and by grinding the disk rotor in accordance with the rotor runout with high estimation accuracy. Rotor runout can be suppressed. As a result, the occurrence of a rotor thickness difference can be suppressed and brake vibration can be suppressed.

  Further, according to the brake control device 1, it is possible to estimate the rotor thickness difference with high accuracy based on the change in the contact state between the pad and the rotor or the change in the braking force relation information. By grinding the disk rotor according to the thickness difference, the rotor thickness difference can be suppressed. As a result, brake vibration can be suppressed, and passenger discomfort due to brake vibration can be prevented.

  In addition, in the brake control device 1, by indirectly estimating the rotor runout and the rotor wall thickness difference based on the load-related load variation and displacement variation, the degree of freedom of mounting of sensing is increased and the size can be reduced. . Further, a load and displacement related to the brake can be detected by using a general-purpose sensor, and furthermore, since the detection means for the rotor runout and the rotor thickness difference is shared, the sensor can also be used and the cost can be reduced. Furthermore, since the brake control device 1 estimates the brake runout and rotor thickness difference when the brake-related temperature is within normal temperature, the influence of rotor thermal deformation can be reduced, and the estimation accuracy of the rotor runout and rotor thickness difference is improved. To do.

  In addition, the brake control device 1 applies a constant pressing force while the vehicle is stopped to hold the braking force related amount constant, and estimates the rotor shake at the start after the stable contact state is established. The estimation accuracy of is improved.

  Further, in the brake control device 1, since the target pressing force and the control start timing are set based on the period and peak of the rotor shake and the rotor thickness difference with high estimation accuracy, the accuracy of the rotor grinding amount is improved. The disk rotor can be ground efficiently. As a result, the durability of the disc rotor and the brake pad can be improved. Further, in the brake control device 1, since the rotor runout is reduced until the rotor runout amount is equal to or less than the specified amount, the rotor runout amount that does not affect the rotor thickness difference growth can be reduced. In the brake control device 1, the rotor thickness difference is reduced until the rotor thickness difference becomes equal to or less than the specified amount. Therefore, the rotor thickness difference that does not affect the occurrence of brake vibration can be reduced. Further, in the brake control device 1, since the target pressing force is set so that the minimum value becomes 0 during non-braking, the grinding amount of the disc rotor can be reduced as much as possible, and the durability of the disc rotor and the brake pad is improved. Can be improved. Furthermore, since the drag torque during non-braking can be reduced as much as possible, fuel efficiency can be improved.

  Further, in the brake control device 1, when setting the target pressing force for reducing the rotor thickness difference during braking, the average pressing force of the pressing force fluctuation during the rotation of the rotor 1 is set to the pressing force according to the required braking force. Therefore, the required braking force can be generated and the rotor thickness difference can be reduced. As a result, the rotor thickness difference reduction time can be shortened, and the occurrence frequency of brake vibration can be reduced.

  Further, in the brake control device 1, during non-braking, when the rotor thickness difference is very large, priority is given to the rotor thickness difference reduction control, so that it is possible to suppress the brake vibration that causes the driver to feel uncomfortable. Further, since the brake control device 1 basically gives priority to the brake shake reduction control during non-braking, it is possible to prevent the growth of the brake thickness difference due to the brake shake.

  In addition, the brake control device 1 reduces the upper limit of the target pressing force in accordance with the longitudinal acceleration during non-braking, so the drag torque between the pad and rotor can be reduced, and the fuel economy and durability of the disc rotor are improved. it can. In addition, the brake control device 1 prohibits the application of pressing force when the brake-related temperature is equal to or higher than the specified temperature during non-braking. Can do.

  As mentioned above, although embodiment which concerns on this invention was described, this invention is implemented in various forms, without being limited to the said embodiment.

  For example, in this embodiment, the present invention is applied to a brake control device that estimates the runout and thickness difference of the disc rotor and suppresses the runout and thickness difference. However, the brake that estimates only the runout of the disc rotor and suppresses runout is applied. The present invention may be applied to a control device, or may be applied to a disc rotor shake detection device.

  In this embodiment, the drag torque is detected by the drag torque sensor as means for detecting the contact state between the pad and the rotor in order to estimate the shake. However, the force changes depending on the contact state in the same manner as the drag torque. It may be a means for detecting the pad surface pressure, tire contact force, torque receiving portion load, or the like, or a means for detecting the relative displacement amount of an indirect member such as a piston, a slide pin, or a brake pad that is displaced depending on the contact state. The contact state is indirectly detected from these relative displacement amounts.

  In the present embodiment, the braking torque is detected as the braking force related information in order to estimate the wall thickness difference. However, as long as the braking force fluctuation during one rotation of the disk rotor during braking, such as hydraulic pressure, can be known. Other information may be used.

  In the present embodiment, the temperature of the brake pad is detected as the brake-related temperature. However, the temperature of other parts such as a disk rotor may be detected.

  In this embodiment, the longitudinal acceleration of the vehicle is detected by the longitudinal acceleration sensor and the maximum value of the target pressing force is reduced by the longitudinal acceleration. However, such a process may not be performed.

It is a lineblock diagram of a brake control device concerning this embodiment. It is explanatory drawing of the fluctuation | variation of a disk rotor. It is an example of the amount of deflection of the disk rotor during one rotation of the rotor. It is explanatory drawing of the thickness difference of a disc rotor. It is a time chart at the time of non-braking concerning this embodiment, (a) is time change of pad temperature, (b) is time change of wheel speed, (c) is time change of vehicle speed, (D) is ON / OFF of the pressurization request for shake / thickness difference reduction, (e) is the time change of the hydraulic pressure of the wheel cylinder, (f) is the time change of the pad / rotor contact state detection amount. Yes, (g) is the time change of the estimated rotor runout, and (h) is the time change of the estimated rotor thickness difference. It is a time chart at the time of braking concerning this embodiment, (a) is time change of pad temperature, (b) is time change of wheel speed, (c) is time change of vehicle speed, d) is the ON / OFF of the pressure request for reducing vibration and thickness difference, (e) is the time change of the hydraulic pressure of the wheel cylinder, (f) is the time change of the braking force, and (g) is It is a time change of an estimated rotor thickness difference. It is a flowchart which shows the flow of the main process in ECU of FIG. It is a flowchart which shows the flow of the rotor shake specific process in ECU of FIG. It is a flowchart which shows the flow of the rotor thickness difference specific process in ECU of FIG. It is a flowchart which shows the flow of the target calculation process (during braking) in ECU of FIG. It is a flowchart which shows the flow of the target calculation process (during non-braking) in ECU of FIG. It is a flowchart which shows the flow of the actuator control process in ECU of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Brake control apparatus, 2 ... Brake pedal sensor, 3 ... Wheel speed sensor, 4 ... Pad temperature sensor, 5 ... Drag torque sensor, 6 ... Braking torque sensor, 7 ... Longitudinal acceleration sensor, 8 ... Brake actuator, 9 ... ECU

Claims (4)

In a brake control device in a disc brake that generates a braking force by pressing a disc rotor with a brake pad,
Pressing means for pressing the brake pads against the disc rotor;
Contact state detection means for detecting a contact state between the running brake pad and the disc rotor;
A brake control device comprising: an estimation unit configured to estimate a shake state of the disk rotor based on a change in the contact state detected by the contact state detection unit.   After the brake pad is brought close to the disc rotor with a constant pressing force by the pressing means at the time of stop, the contact state is detected by the contact state detecting means at the start, and based on the change of the contact state at the start by the estimating means The brake control device according to claim 1, wherein a shake state of the disk rotor is estimated.   The brake pad is pressed against the disk rotor by the pressing means with a pressing force at which the deceleration of the vehicle body is equal to or less than a predetermined deceleration according to the disc rotor swing state estimated by the estimating means during non-braking. The brake control device according to claim 1 or 2.   4. The brake control device according to claim 1, wherein priority is given to the disc rotor deflection suppression control over the disc rotor circumferential thickness difference suppression control. 5.

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