JP7005421B2 - Electric brake device - Google Patents

Description

The present invention relates to an electric braking device that applies braking force to a vehicle such as an automobile.

The electric brake device transmits the thrust generated by the drive of the electric motor to the piston that moves the brake pad pressed against the disc. The electric braking device includes a thrust sensor that detects the thrust, a current sensor that detects the current supplied to the electric motor, and a rotation angle sensor that detects the rotation position of the electric motor. Patent Document 1 discloses that an abnormality of a thrust sensor, a current sensor, and a rotation angle sensor is detected.

Japanese Unexamined Patent Publication No. 2007-45271

When the thrust sensor is normal, the electric braking device calculates the braking force based on the thrust value acquired by the thrust sensor, and generates a braking force suitable for the vehicle state and the driving situation.

On the other hand, when an abnormality occurs in the thrust sensor, the thrust value becomes undefined, which makes it difficult to calculate the optimum braking force. In this case, the electric brake device described in Patent Document 1 generates a braking force that does not match the vehicle state or the driving situation. As a result, it causes a difference in braking force between the left and right wheels, which may destabilize the vehicle behavior.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide an electric brake device capable of stabilizing vehicle behavior even when an abnormality occurs in the thrust detecting means. It is in.

In order to solve the above-mentioned problems, the present invention comprises an electric motor that propels the braking member and applies thrust to the piston that presses the braked member, a plurality of thrust detecting means for detecting the thrust of the piston, and a current of the electric motor. In an electric braking device including a current detecting means for detecting a value, a control device for controlling the electric motor, and an abnormality diagnosing device for determining an abnormality in the thrust detecting means, the abnormality diagnosing device transmits from the control device. When the abnormality of the thrust detecting means is determined based on the comparison result between the detection values of the plurality of thrust detecting means and the detection values of the current detecting means, and the thrust detecting means is determined to be abnormal, the said. An estimated value of thrust is sent to the control device, and the control device is made to control the electric motor based on the estimated value, and the detection value of the thrust detecting means and the detection value of the current detecting means can be detected. The relationship between the maximum value and the minimum value is preset, and the detected value of the detected thrust and the detected value of the detected current are linearly interpolated with respect to the preset relationship, based on the aging deterioration of the braking member. It is characterized in that the deterioration correction value of the thrust value is calculated, and the estimated value of the thrust is calculated from the relationship between the current value and the deterioration correction value .

Further, in another invention, an electric motor that propels a braking member and applies thrust to a piston that presses the braked member, a plurality of thrust detecting means for detecting the thrust of the piston, and a current detection for detecting the current value of the electric motor. In an electric braking device including means, a plurality of control devices for controlling the electric motor, and an abnormality diagnosis device for determining an abnormality of the thrust detecting means, the abnormality diagnosis device is used for each wheel transmitted from the control device. The correlation between the detection value of the thrust detecting means and the detection value of the current detecting means is acquired, and the abnormality of the thrust detecting means is determined depending on whether or not there is a predetermined relationship for each wheel, and the thrust detecting means. If it is determined that is abnormal, the control device is made to control the electric motor based on the estimated value of the thrust based on the correlation in the wheel determined to be abnormal, and the thrust detecting means is detected. The relationship between the maximum value and the minimum value that can be detected is preset for the value and the detected value of the current detecting means, and the detected value of the detected thrust and the detected value of the detected current are set in advance for the preset relationship. By performing linear interpolation, the deterioration correction value of the thrust value based on the aged deterioration of the braking member is calculated, and the estimated value of the thrust is calculated from the relationship between the current value and the deterioration correction value .

According to the present invention, even when an abnormality occurs in the thrust detecting means, the control device can control the electric motor based on the estimated value of the thrust, and the vehicle behavior can be stabilized.

It is a block diagram which shows the system structure of the electric brake device by embodiment of this invention. It is a block diagram which shows the structure which the electric brake device provided with three control devices. It is a characteristic diagram which shows the relationship between a motor current and a thrust. It is explanatory drawing which shows the example which detected the abnormality of the thrust detection part. It is a flow chart which shows the control process at the time of failure. It is a flow chart which shows the thrust abnormality detection processing. It is a flow chart which shows the abnormality notification processing. It is a flow chart which shows the thrust estimation learning process. It is a characteristic diagram which shows the relationship between a motor current and an estimated thrust. It is a block diagram which shows the structure which the electric brake device by a modification is provided with four control devices.

Hereinafter, the case where the electric brake device according to the embodiment is applied to a four-wheeled vehicle will be described as an example with reference to the attached drawings.

FIG. 1 shows a configuration diagram of the entire system. Calipers 1FL and 1FR are provided on the left and right front wheels. Calipers 1RL and 1RR are provided on the left and right rear wheels. The electric brake device 2 includes a front wheel brake device 3 provided corresponding to the left and right front wheels, and rear wheel brake devices 4L and 4R provided corresponding to the left and right rear wheels.

The front wheel brake device 3 generates braking force for only the two front wheels. The front wheel brake device 3 is composed of a hydraulic brake device that generates a braking force by hydraulic pressure, and controls the operation of the calipers 1FL and 1FR. The front wheel brake device 3 includes a hydraulic unit, a master cylinder (M / C) pressure sensor, a system pressure sensor, and a solenoid (none of which are shown) to control hydraulic pressure. When hydraulic control cannot be realized, the front wheel brake device 3 is configured to be able to increase the pressure without boosting by operating the brake pedal. The calipers 1FL and 1FR generate a braking force according to the hydraulic pressure applied from the front wheel braking device 3.

As shown in FIG. 2, the rear wheel brake devices 4L and 4R control the operation of the calipers 1RL and 1RR to generate braking force for the rear two wheels. The rear wheel brake device 4L on the left side includes an electric motor 5L, a thrust detection unit 8L, and a current detection unit 9L. The electric motor 5L applies thrust to the piston 7L that propels the brake pad 6L that is the braking member and presses the disc D that is the braking member. Similarly, the rear wheel brake device 4R on the right side includes an electric motor 5R, a thrust detection unit 8R, and a current detection unit 9R. The electric motor 5R applies thrust to the piston 7R that propels the brake pad 6R and presses the disc D. The rear wheel brake devices 4L and 4R are electric brake devices that generate braking force by moving the brake pads 6L and 6R by the electric motors 5L and 5R.

The thrust detection units 8L and 8R detect the thrust of the pistons 7L and 7R. The thrust detection unit 8L constitutes a thrust detection means by two systems. The thrust detection means using two systems is, for example, two systems by branching the output of one thrust detection unit 8L and acquiring using both A / D conversion and SENT (Single Edge Nibble Transmission) communication. The thrust detection means using the two systems may be two systems in which the thrust detection units 8L are located around the piston 7L and provided at different angles, and each uses A / D conversion and SENT communication. Like the thrust detection unit 8L, the thrust detection unit 8R also constitutes a thrust detection means using two systems. The current detection units 9L and 9R each configure current detection means and detect the current of the motors 5L and 5R, respectively.

The vehicle is provided with a Yaw / G detection unit 10 that detects yawing and acceleration as means for vehicle control calculation and estimation of the vehicle state. The vehicle may be provided with a steering angle sensor for acquiring steering angle information instead of the Yaw / G detection unit 10. The Yaw / G detection unit 10 is connected to the first arithmetic unit 31.

Further, the wheel speed detection units 11FL, 11FR, 11RL, and 11RR are attached to the calipers 1FL, 1FR, 1RL, and 1RR to detect the wheel speeds of each of the four wheels. The first arithmetic unit 31 is connected to the wheel speed detection units 11FL and 11FR of the left and right front wheels, and can detect the wheel speeds of the left and right front wheels. The second arithmetic unit 36 is connected to the wheel speed detection units 11RL and 11RR of the left and right rear wheels, and can detect the wheel speeds of the left and right rear wheels.

The vehicle is provided with a stroke amount detecting unit 12 as a means for detecting the brake pedal operation amount of the driver. Instead of the stroke amount detecting unit 12, the vehicle may be provided with a pedaling force detecting unit that detects the pedaling force of the pedal. The stroke amount detection unit 12 is connected to the second arithmetic unit 36.

The first arithmetic unit 31, the second arithmetic unit 36, the third arithmetic unit 42, and the fourth arithmetic unit 48 are connected in a state in which they can communicate with each other. Therefore, these arithmetic units 31, 36, 42, 48 are connected by networks 13 to 15. The communication means of the networks 13 to 15 may be any of CAN (Controller Area Network), P2P (Pear to Pear), and SPI (Serial Peripheral Interface) communication. The arithmetic units 31, 36, 42, and 48 can transmit the acquired sensor signal, the detection information, and the calculated braking force command to the residual arithmetic unit by communication. As a result, the detection values of the thrust detection units 8L and 8R and the detection values of the current detection units 9L and 9R are the third calculation of the first arithmetic unit 31, the second arithmetic unit 36 and the control devices 22 and 23 of the control device 21. Information is always shared between the device 42 and the fourth arithmetic unit 48.

The first arithmetic unit 31 and the second arithmetic unit 36 receive signals from the thrust detection unit 8L, 8R, the current detection unit 9L, 9R, the Yaw / G detection unit 10, and the wheel speed detection unit 11FL, 11FR, 11RL, 11RR. Then, the braking force is calculated for the four wheels according to the specified control program. The first arithmetic unit 31 transmits a command to the two left and right front wheels to the front wheel brake device 3. The second arithmetic unit 36 transmits commands to the two left and right rear wheels to the rear wheel brake devices 4L and 4R.

The electric brake device 2 includes, for example, three control devices 21 to 23 for controlling the brake device. FIG. 2 shows a configuration example of the electric brake device 2.

The control device 21 includes a first arithmetic unit 31 that controls the front wheel brake device 3, and a second arithmetic unit 36 that controls the rear wheel brake devices 4L and 4R.

The control device 22 is provided in the rear wheel brake device 4L, and includes a third arithmetic unit 42 that controls the rear wheel brake device 4L, a thrust detection unit 8L, and a current detection unit 9L.

The control device 23 is provided in the rear wheel brake device 4R, and includes a fourth arithmetic unit 48 that controls the rear wheel brake device 4R, a thrust detection unit 8R, and a current detection unit 9R.

When the electric brake device 2 includes three control devices 21 to 23, the front and rear brake devices 3, 4L and 4R can be controlled by the three control devices 21 to 23. Therefore, as compared with the case where four control devices corresponding to the arithmetic units 31, 36, 42, and 48 are provided, it is advantageous in reducing the number of parts of the entire electric brake device 2 and reducing the vehicle cost. ..

The first arithmetic unit 31 of FIG. 1 includes a first control unit 32, a first abnormality detection unit 33, a first abnormality determination unit 34, and a first communication function unit 35. The first arithmetic unit 31 controls the hydraulic unit and the solenoid provided in the front wheel brake device 3 based on the braking force calculated by the first control unit 32. When the front wheel brake device 3 is abnormal, the first abnormality detecting unit 33 detects the abnormality, and the first abnormality determining unit 34 determines the abnormality. The first communication function unit 35 communicates with the arithmetic units 36, 42, 48.

The second arithmetic unit 36 of FIG. 1 includes a second control unit 37, a failure control calculation unit 38, a second abnormality detection unit 39, a second abnormality determination unit 40, and a second communication function unit 41. The second control unit 37 assumes a vehicle state based on, for example, information from the Yaw / G detection unit 10, and calculates the braking force to be generated by the rear wheel brake devices 4L and 4R according to the vehicle state. The second arithmetic unit 36 issues a command to the third arithmetic unit 42 and the fourth arithmetic unit 48 of the rear wheel brake devices 4L and 4R based on the calculated braking force. When the rear wheel brake devices 4L and 4R are abnormal, the second abnormality detecting unit 39 detects the abnormality, and the second abnormality determining unit 40 determines the abnormality. The second communication function unit 41 communicates with the arithmetic units 31, 42, 48. The failure control calculation unit 38 performs a control calculation when a thrust abnormality is detected.

The second arithmetic unit 36 can communicate with another arithmetic unit 24. The second arithmetic unit 36 also acquires, for example, steering angle information and recognition of commands necessary for automatic braking such as collision prevention by using communication means such as CAN, P2P, and SPI communication.

The third arithmetic unit 42 of FIG. 1 includes an estimated thrust learning unit 43, a thrust abnormality detecting unit 44, a thrust abnormality notification unit 45, a communication function unit 46, and a third control unit 47. The estimated thrust learning unit 43 updates a graph (estimated thrust graph G0) showing the correlation between the motor current [A] and the estimated thrust [kN] as shown in FIG. 3 for thrust estimation. The thrust abnormality detection unit 44 determines the abnormality of the thrust detection unit 8L. The thrust abnormality notification unit 45 notifies the second arithmetic unit 36 of the abnormality of the thrust detection unit 8L via the communication function unit 46. The communication function unit 46 has a function of communicating with the arithmetic units 31, 36, 48. The third control unit 47 controls the rear wheel brake device 4L based on the braking force command from the second arithmetic unit 36.

The fourth arithmetic unit 48 in FIG. 1 also has the third arithmetic unit 42 configured in substantially the same manner. Therefore, the fourth arithmetic unit 48 includes an estimated thrust learning unit 49, a thrust abnormality detecting unit 50, a thrust abnormality notification unit 51, a communication function unit 52, and a fourth control unit 53. The estimated thrust learning unit 49 updates a graph (estimated thrust graph G0) showing the correlation between the motor current [A] and the estimated thrust [kN] as shown in FIG. 3 for thrust estimation. The thrust abnormality detection unit 50 determines the abnormality of the thrust detection unit 8R. The thrust abnormality notification unit 51 notifies the second arithmetic unit 36 of the abnormality of the thrust detection unit 8R via the communication function unit 52. The communication function unit 52 has a function of communicating with the arithmetic units 31, 36, 42. The fourth control unit 53 controls the rear wheel brake device 4R based on the braking force command from the second arithmetic unit 36.

5 to 8 show a process of controlling the electric brake device 2 and a process associated therewith.

The steps in the flow chart shown in FIGS. 5 to 8 use the notation “S”, and step 1 is shown as “S1”, for example. Further, the processes shown in FIGS. 5 to 8 are executed separately and in parallel at a predetermined control cycle.

First, the process of controlling the electric brake device 2 will be described with reference to FIG. FIG. 5 shows a failure control process executed by the second arithmetic unit 36.

In S1 to S3, it is determined whether or not an abnormality has occurred in the thrust detection units 8L and 8R provided in the rear wheel brake devices 4L and 4R.

Specifically, in S1, the second arithmetic unit 36 determines whether there is an abnormality notification and notification interruption of the thrust detection units 8L and 8R from the thrust abnormality notification units 45 and 51 of the rear wheel brake devices 4L and 4R. .. When it is determined as "NO" in S1, since there is no abnormality notification, the process is terminated as it is. On the other hand, when it is determined as "YES" in S1, there is an abnormality notification, so the process proceeds to S2.

Actually, there is a possibility of an abnormality other than the thrust detection units 8L and 8R due to garbled bits and network disconnection. Therefore, in S2, the information acquired from the three network routes is always acquired, and the results from the three routes are compared and verified by majority voting.

FIG. 4 shows an example in which an abnormality in the thrust detection unit 8L is detected. When an abnormality occurs in the thrust detection unit 8L connected to the third arithmetic unit 42, the path 61 and the third arithmetic input from the third arithmetic unit 42 to the second arithmetic unit 36 via the first arithmetic unit 31. Abnormal notification is made through a total of three routes, a route 62 input from the device 42 to the second arithmetic unit 36 and a route 63 input from the third arithmetic unit 42 to the second arithmetic unit 36 via the fourth arithmetic unit 48. Information is transmitted to the second arithmetic unit 36. Therefore, the second arithmetic unit 36 compares the abnormality notification information transmitted from these three routes 61 to 63, and when the abnormality notification information from the two or more routes is abnormal, the abnormality of the thrust detection unit 8L is detected. Determine. This point is the same when an abnormality occurs in the thrust detection unit 8R.

If the abnormality notification information from one route is abnormal, it is determined as "NO" in S3, and the process proceeds to S7. In S7, it is determined that an abnormality other than the thrust detection units 8L and 8R or the thrust detection units 8L and 8R are normal.

When it is determined that there is an abnormality in the thrust detection units 8L and 8R, it is determined as "YES" in S3, and the process proceeds to S4. In S4, the motor current value is acquired from the current detection unit of the rear wheel brake device on the side where the abnormality has occurred in order to estimate the thrust. That is, when an abnormality has occurred in the rear wheel brake device 4L, the motor current value is acquired from the current detection unit 9L. Similarly, when an abnormality has occurred in the rear wheel brake device 4R, the motor current value is acquired from the current detection unit 9R.

In S5, using the acquired motor current value, the estimated thrust is used by using the motor current of the estimated thrust learning unit (for example, the estimated thrust learning unit 43) of the rear wheel braking device (for example, the rear wheel braking device 4L) in which the abnormality has occurred. The thrust generated from the graph G0 is estimated. The estimated thrust graph G0 defines the estimated thrust value with respect to the magnitude of the motor current value, as shown by the solid line in FIG.

In the following S6, the estimated thrust value is sent to the second control unit 37. The second control unit 37 performs a calculation based on the estimated values from the rear wheel brake devices 4L and 4R, and outputs a control command. By sending the estimated thrust value to the second control unit 37, it is possible to send a command considering the difference in thrust between the left and right to the rear wheel brake devices 4L and 4R, and generate a braking force in the same manner as in the normal state.

Next, the thrust abnormality detection process by the thrust abnormality detection units 44 and 50 will be described with reference to FIG. FIG. 6 shows the thrust abnormality detection processing executed by the thrust abnormality detection units 44 and 50, respectively. The thrust abnormality detection units 44 and 50 execute the same thrust abnormality detection process. Therefore, here, a case where the thrust abnormality detection unit 44 executes the thrust abnormality detection process will be described as an example.

In S11, the thrust values are acquired from the thrust detection units 8L of the two systems. In the following S12, the thrust values of the two systems acquired from the thrust detection unit 8L are compared. In the following S13, it is determined whether or not the thrust values of the two systems are fixed, that is, whether or not the thrust values do not change even if the motor current increases. When it is determined as "NO" in S13, the thrust value is not fixed, so the process is terminated as it is.

On the other hand, when it is determined as "YES" in S13, the thrust value is fixed, so the process proceeds to S14. In S14, the stuck thrust detection unit 8L is specified. In the following S15, the thrust abnormality detection unit 44 issues an abnormality notification to the thrust abnormality notification unit 45.

Next, the thrust abnormality notification processing by the thrust abnormality notification units 45 and 51 will be described with reference to FIG. 7. FIG. 7 shows the thrust abnormality notification processing executed by the thrust abnormality notification units 45 and 51, respectively. FIG. 7 shows the thrust abnormality notification processing executed by the thrust abnormality notification units 45 and 51, respectively. The thrust abnormality notification units 45 and 51 execute the same thrust abnormality notification process. Therefore, here, a case where the thrust abnormality notification unit 45 executes the thrust abnormality notification process will be described as an example.

In S21, it is determined whether or not there is an abnormality notification issued by the thrust abnormality detecting unit 44. When it is determined as "NO" in S21, since the abnormality notification has not been issued, the process is terminated as it is. On the other hand, when it is determined as "YES" in S21, since the abnormality notification is issued, the process proceeds to S22. In S22, the thrust abnormality notification unit 45 transmits the abnormality notification as abnormality notification information to the first arithmetic unit 31 and the second arithmetic unit 36. As a result, the abnormality notification is transmitted to the failure control calculation unit 38 of the second calculation device 36.

Next, the estimated thrust learning process by the estimated thrust learning units 43 and 49 will be described with reference to FIG. FIG. 8 shows the estimated thrust learning process executed by the estimated thrust learning units 43 and 49, respectively. The estimated thrust learning process updates the estimated thrust graph G0 showing the correlation between the motor current [A] and the thrust [kN] used in S5 of the failure control calculation process shown in FIG. The estimated thrust learning units 43 and 49 execute the same estimated thrust learning process. Therefore, here, a case where the estimated thrust learning unit 43 executes the estimated thrust learning process will be described as an example.

First, a graph showing the correlation between the motor current [A] and the thrust [kN] will be described. There is a linear proportional relationship between the motor current [A] and the generated thrust [kN], for example, as shown in FIG. Therefore, if the motor current value [A] is acquired when the brake pad 6L and the disc D come into contact with each other, the estimated thrust [kN] can be obtained.

However, in reality, in addition to the aged deterioration and wear of the brake pad 6L, there are also differences in the environment such as temperature. Due to these factors, even if the motor current value [A] is a constant value, the actual thrust value [kN] may differ. Therefore, the estimated thrust learning unit 43 updates the graph (estimated thrust graph G0) showing the correlation between the motor current [A] and the thrust [kN], and obtains the difference between the actual thrust (actual thrust) and the estimated thrust. It is suppressing.

In S31 of FIG. 8, the maximum value Imax and the minimum value Imin of the motor current [A] from the current detection unit 9L, and the maximum value Fmax and the minimum value Fmin of the thrust value [kN] from the thrust detection unit 8L are traveling. Always get and update. While the vehicle is running, the braking operation is repeatedly executed. At this time, by acquiring the motor current [A] from the current detection unit 9L and the thrust value [kN] from the thrust detection unit 8L, the maximum values Imax and Fmax and the minimum values Imin and Fmin are acquired, respectively. be able to.

The estimated thrust graph G0 is updated when the vehicle is stopped. Therefore, in S32, the wheel speed is acquired from the wheel speed detection unit 11RL. In the following S33, the stroke operation amount from the stroke amount detection unit 12 is acquired. In the following S34, the vehicle is determined to stop based on the wheel speed and the stroke operation amount.

When it is determined as "NO" in S34, the vehicle is in a running state, so the process is terminated as it is. On the other hand, when it is determined as "YES" in S34, the vehicle is in a stopped state, so the vehicle shifts to S35. In S35, linear interpolation is performed between two points with reference to the acquired maximum value Imax and minimum value Imin of the motor current value [A] and the maximum value Fmax and minimum value Fmin of the thrust value [kN]. As a result, the linear interpolation graph G1 shown by the broken line in FIG. 9 is created.

In the following S36, a graph G2 (dashed line in FIG. 9) and a linear interpolation graph G1 showing the relationship between the normal motor current value [A] and the thrust value [kN] of the two systems of the thrust detection unit 8L are displayed. It is used to calculate the intermediate value of the estimated thrust value [kN] with respect to the motor current value [A]. Based on this intermediate value, an estimated thrust graph G0 shown by a solid line in FIG. 9 is created.

As described above, the estimated thrust learning unit 43 uses the intermediate value between the graph G2 of the normal motor current value [A] and the thrust value [kN] and the linear interpolation graph G1 of the two systems of the thrust detection unit 8L. , Create an estimated thrust graph G0. At this time, the failure control calculation unit 38 uses the estimated thrust graph G0 to obtain a thrust value based on the aged deterioration of the brake pads 6L and 6R (braking member) from the motor current [A] from the current detection unit 9L. Calculates the deterioration correction value of. In this way, the failure control calculation unit 38 calculates the estimated value of the thrust from the relationship between the current value and the deterioration correction value. This prevents a large difference between the actually generated thrust (actual thrust) and the estimated thrust calculated based on the estimated thrust graph G0.

In S37, the previously created estimated thrust graph G0 is updated with the new estimated thrust graph G0 created in S36. S36 and S37 are executed while the vehicle is stopped. Therefore, the relationship between the current value and the deterioration correction value is the static state in which the vehicle that generated the braking force by propelling the brake pads 6L and 6R (braking member) and pressing the disc D (braked member) is stopped. Then, it is updated using the acquired current value and thrust value. The updated estimated thrust graph G0 is transmitted to the second arithmetic unit 36. As a result, the failure control calculation unit 38 of the second calculation device 36 can estimate the thrust value from the current value detected by the current detection unit 9L using the estimated thrust graph G0.

When both of the thrust detection units 8L of the two systems are normal, the second arithmetic unit 36 determines that the thrust detection unit 8L is normal. In this case, the second arithmetic unit 36 does not follow the estimated thrust graph G0 of FIG. 9, and controls the rear wheel brake device 4L using the thrust value [kN] output from the thrust detection unit 8L. On the other hand, when any one of the thrust detection units 8L of the two systems is abnormal, the second arithmetic unit 36 determines that the thrust detection unit 8L is abnormal. In this case, the second arithmetic unit 36 controls the rear wheel brake device 4L based on the estimated value of the thrust calculated based on the estimated thrust graph G0.

Thus, in the present embodiment, the electric brake device 2 has the electric motors 5L, 5R and the pistons that propel the brake pads 6L, 6R (braking member) and press the disc D (braked member) to give thrust to the pistons 7L, 7R. Multiple systems of thrust detection units 8L, 8R that detect the thrust of 7L, 7R, current detection units 9L, 9R that detect the current values of the motors 5L, 5R, and control devices 22, 23 that control the motors 5L, 5R. , Is provided for each rear wheel. In addition to this, the electric brake device 2 includes a second arithmetic unit 36 as an abnormality diagnosis device for determining an abnormality of the thrust detection units 8L and 8R.

Then, the second arithmetic unit 36 is based on the comparison result between the detection values of the thrust detection units 8L and 8R of the plurality of systems transmitted from the control devices 22 and 23 and the detection values of the current detection units 9L and 9R, and the thrust detection unit 8L. , 8R is judged to be abnormal, and when the thrust detection units 8L and 8R are judged to be abnormal, the estimated value of the thrust is sent to the control devices 22 and 23, and the electric motor is sent to the control devices 21 and 22 based on the estimated value. Control 5L and 5R.

Specifically, the second arithmetic unit 36 acquires the correlation between the detection values of the thrust detection units 8L and 8R for each wheel transmitted from the control devices 22 and 23 and the detection values of the current detection units 9L and 9R. , The abnormality of the thrust detection units 8L and 8R means is determined based on whether or not each wheel has a predetermined relationship, and when it is determined that the thrust detection units 8L and 8R are abnormal, the wheel determined to be abnormal is used. The control devices 22 and 23 are made to control the electric motors 5L and 5R based on the estimated value of the thrust based on the correlation.

As a result, even when an abnormality occurs in the thrust detection units 8L and 8R, the motors 5L and 5R are controlled by using the thrust estimation values based on the detection values of the current detection units 9L and 9R to stabilize the vehicle behavior. be able to.

Further, the detection values of the thrust detection units 8L and 8R and the detection values of the current detection units 9L and 9R are always shared between the second arithmetic unit 36 (control device 21) and the control devices 22 and 23. ..

Therefore, when the thrust detection units 8L and 8R are normal, the second arithmetic unit 36 can control the rear wheel brake devices 4L and 4R based on the detection values of the thrust detection units 8L and 8R. When the thrust detection units 8L and 8R are abnormal, the second arithmetic unit 36 (failure control calculation unit 38) is based on the estimated thrust value obtained from the detection values of the current detection units 9L and 9R. , Rear wheel brake devices 4L, 4R can be controlled.

Further, the relationship between the maximum detectable values Fmax and Imax and the minimum values Fmin and Imin with respect to the detected values of the thrust detecting units 8L and 8R and the detected values of the current detecting units 9L and 9R is preset and the detected thrust is measured. By linearly interpolating the detected value and the detected value of the detected current with respect to the preset relationship, the deterioration correction value of the thrust value based on the aged deterioration of the brake pads 6L and 6R (braking member) is calculated. The estimated value of thrust is calculated from the relationship between the current value and the deterioration correction value.

As a result, the estimated value of the thrust calculated from the relationship between the current value and the deterioration correction value can be brought closer to the actually generated thrust (actual thrust), and the difference between the actual thrust and the estimated value of the thrust can be suppressed. can do.

The relationship between the current value and the deterioration correction value is that the vehicle that generated the braking force by propelling the brake pads 6L and 6R (braking member) and pressing the disc D (braked member) is in a static state. In some cases, the acquired current value and thrust value are used for updating.

If the relationship between the current value and the deterioration correction value is updated while the vehicle is running, the braking force changes with the update, and the vehicle may become unstable. On the other hand, since the relationship between the current value and the deterioration correction value is updated when the vehicle is stopped, the vehicle can be kept in a stable state even if the braking force changes with the update.

Further, even if the thrust detection units 8L and 8R change from the normal state to the abnormal state while the vehicle is running, the relationship between the current value and the deterioration correction value is not updated until the vehicle is stopped. On the other hand, in the present embodiment, the estimated value of the thrust is obtained by using the latest current value and the deterioration correction value at the time of determining normality immediately before the second arithmetic unit 36 determines that it is abnormal. Therefore, since the difference between the actual thrust and the estimated value of the thrust can be suppressed, the vehicle behavior is stable even when the control devices 22 and 23 control the motors 5L and 5R based on the estimated value of the thrust. Can be transformed.

In the embodiment, the electric brake device 2 includes three control devices 21 to 23. The present invention is not limited to this, and may be configured to include four control devices 71, 72, 22, 23, for example, as in the electric brake device 70 of the modified example shown in FIG. In this case, the first arithmetic unit 31 that controls the front wheel brake device 3 and the second arithmetic unit that controls the rear wheel brake devices 4L and 4R are provided in separate control devices 71 and 72.

In the above embodiment, the electric rear wheel brake devices 4L and 4R are applied to the rear wheels, but the electric front wheel brake device may be applied to the front wheels, and the electric brake device may be applied to all four wheels. May be applied.

As the electric brake device based on the embodiment described above, for example, the one described below can be considered.

As the first aspect, an electric motor that propels the braking member and applies thrust to the piston that presses the braked member, a plurality of thrust detecting means for detecting the thrust of the piston, and a current detection for detecting the current value of the electric motor. In an electric brake device including means, a control device for controlling the electric motor, and an abnormality diagnosis device for determining an abnormality of the thrust detection means, the abnormality diagnosis device is a plurality of thrusts transmitted from the control device. Based on the comparison result between the detection value of the detection means and the detection value of the current detection means, the abnormality of the thrust detection means is determined, and when it is determined that the thrust detection means is abnormal, the thrust is estimated to the control device. It is characterized in that a value is sent and the control device controls the electric motor based on the estimated value.

The second aspect is an electric motor that propels the braking member and applies thrust to the piston that presses the braked member, a plurality of thrust detecting means for detecting the thrust of the piston, and a current detection that detects the current value of the electric motor. In an electric braking device including means, a plurality of control devices for controlling the electric motor, and an abnormality diagnosis device for determining an abnormality of the thrust detecting means, the abnormality diagnosis device is used for each wheel transmitted from the control device. The correlation between the detection value of the thrust detecting means and the detection value of the current detecting means is acquired, and the abnormality of the thrust detecting means is determined depending on whether or not there is a predetermined relationship for each wheel, and the thrust detecting means. When it is determined that is abnormal, the control device is made to control the motor based on the estimated value of the thrust based on the correlation in the wheel determined to be abnormal.

As a third aspect, in the first or second aspect, the detection value of the thrust detecting means and the detection value of the current detecting means always share information between the abnormality diagnosis device and the control device. It is characterized by.

As the fourth aspect, in any one of the first to third aspects, the relationship between the maximum value and the minimum value that can be detected with respect to the detection value of the thrust detecting means and the detection value of the current detecting means is preset. Then, by linearly interpolating the detected value of the detected thrust and the detected value of the detected current with respect to the preset relationship, the deterioration correction value of the thrust value based on the aging deterioration of the braking member is calculated. It is characterized in that the estimated value of the thrust is calculated from the relationship between the current value and the deterioration correction value.

As a fifth aspect, in the fourth aspect, the relationship between the current value and the deterioration correction value is a static state in which the vehicle in which the braking member is propelled and the braked member is pressed to generate the braking force is stopped. In the case of, it is characterized by updating using the acquired current value and thrust value.

As a sixth aspect, in the fourth aspect, the estimated value of the thrust uses the latest current value and the deterioration correction value at the time of determining normality immediately before the abnormality diagnosis device determines that it is abnormal. It is characterized by being calculated.

2,70 Electric brake device 3 Front wheel brake device 4L, 4R Rear wheel brake device 5L, 5R Electric motor 6L, 6R Brake pad 7L, 7R Piston 8L, 8R Thrust detector 9L, 9R Current detector 21-23, 71,72 Control Device 31 First arithmetic unit 36 Second arithmetic unit 38 Failure control calculation unit 39 Second abnormality detection unit 40 Second abnormality judgment unit 42 Third arithmetic unit 43,49 Estimated thrust learning unit 44,50 Thrust abnormality detection unit 45 , 51 Thrust abnormality notification unit 48 4th arithmetic unit

Claims (5)

An electric motor that propels the braking member and applies thrust to the piston that presses the braking member,
A plurality of thrust detecting means for detecting the thrust of the piston, and
A current detection means for detecting the current value of the motor and
A control device that controls the motor and
In an electric brake device including an abnormality diagnosis device for determining an abnormality of the thrust detecting means.
The abnormality diagnosis device is
An abnormality of the thrust detecting means is determined based on a comparison result between the detection values of the plurality of thrust detecting means transmitted from the control device and the detection values of the current detecting means.
When it is determined that the thrust detecting means is abnormal, an estimated value of thrust is sent to the control device, and the control device is made to control the motor based on the estimated value .
The relationship between the maximum value and the minimum value that can be detected is set in advance with respect to the detection value of the thrust detection means and the detection value of the current detection means, and the detection value of the detected thrust and the detection value of the detected current are set in advance. By linearly interpolating the set relationship, the deterioration correction value of the thrust value based on the aged deterioration of the braking member is calculated, and the estimated value of the thrust is calculated from the relationship between the current value and the deterioration correction value. An electric braking device featuring. An electric motor that propels the braking member and applies thrust to the piston that presses the braking member,
A plurality of thrust detecting means for detecting the thrust of the piston, and
A current detection means for detecting the current value of the motor and
A plurality of control devices for controlling the motor and
In an electric brake device including an abnormality diagnosis device for determining an abnormality of the thrust detecting means.
The abnormality diagnosis device is
The correlation between the detection value of the thrust detecting means for each wheel and the detection value of the current detecting means for each wheel transmitted from the control device is acquired, and the thrust detecting means of the thrust detecting means is determined depending on whether or not there is a predetermined relationship for each wheel. Judging the abnormality,
When it is determined that the thrust detecting means is abnormal, the control device is made to control the electric motor based on the estimated value of the thrust based on the correlation in the wheel determined to be abnormal .
The relationship between the maximum value and the minimum value that can be detected is set in advance with respect to the detection value of the thrust detection means and the detection value of the current detection means, and the detection value of the detected thrust and the detection value of the detected current are set in advance. By linearly interpolating the set relationship, the deterioration correction value of the thrust value based on the aged deterioration of the braking member is calculated, and the estimated value of the thrust is calculated from the relationship between the current value and the deterioration correction value. An electric braking device featuring. In the electric brake device according to claim 1 or 2.
An electric brake device characterized in that the detection value of the thrust detecting means and the detection value of the current detecting means always share information between the abnormality diagnosis device and the control device. In the electric brake device according to any one of claims 1 to 3 .
The relationship between the current value and the deterioration correction value is the acquired current value and thrust value when the vehicle that generated the braking force by propelling the braking member and pressing the braking member is in a static state. An electric brake device characterized by being used and updated. In the electric brake device according to any one of claims 1 to 3 .
The electric brake device is characterized in that the estimated value of the thrust is calculated by using the latest current value and deterioration correction value at the time of determining normality immediately before the abnormality diagnosis device determines that it is abnormal.

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