JP2003063376A - Dynamo electric brake system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a driver aware of abnormality in a pressing force sensor for detecting a pressing force promptly and surely, in a vehicle which performs brake control by detecting the pressing force of a brake friction member to a rotary body rotating with a wheel. SOLUTION: When the abnormality in the pressing force sensor is detected, the abnormality in the sensor is surely made to be perceived by the driver by transferring the feeling of the pedal operation to the driver, which is generated by unusual vehicle speed reduction by outputting the brake control amount to a motor based on an abnormal target pressing force which is different from a normal state by switching the normal brake control to the abnormal brake control.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric brake device equipped with electric braking means such as an electric motor.

[0002]

2. Description of the Related Art In recent years, in addition to a hydraulic brake device using a working fluid, an electric motor is driven and rotated according to the amount of depression of a brake pedal, and a braking force is generated using the rotational force of the electric motor. Brake systems are being developed. As such an electric brake device, for example, the one described in Japanese Patent Laid-Open No. 9-137841 has been proposed.

The electric brake device described in this publication detects an electric actuator that drives a friction member forward and backward toward a rotating body that rotates together with a wheel, and an urging force that acts on the friction member from the actuator. A thrust sensor, a position sensor that detects the position of the friction material, and a control unit that controls the operation of the actuator based on the operation status of a brake operating unit are provided, and the control unit includes a thrust sensor of the thrust sensor. A thrust control function for controlling the operation of the actuator based on the detection signal and a position control function for controlling the operation of the actuator based on the detection signal of the position sensor are provided.

[0004]

However, even if the thrust sensor fails, the electric brake device in the above-mentioned conventional example is capable of braking by estimating the thrust from the friction pad position and caliper rigidity detected by the position sensor. Is possible. Here, the relationship between the amount of brake operation and the piston position based on this, and the pressing force generated by the friction pad is as shown in FIG. 21, and when the amount of increase in the piston position is normal, the pedal position is indicated by the characteristic line L1. Although it is substantially equal to the amount of increase in the amount of operation, a characteristic line L2 showing wear and decrease in rigidity of the friction pad and a characteristic line L3 showing thermal expansion and improvement in rigidity of the friction pad show the amount of increase in the amount of brake operation. The relationship between the amount of increase in the piston position and the corresponding pressing force constantly fluctuates with each braking. Therefore, as shown in FIG. 22, when the pressing force is estimated from the normal piston position, a value lower than the actual pressing force is estimated in the braking characteristic 2 state, and the actual pressing force is estimated in the braking characteristic 3 state. Since a value higher than the pressure is estimated, an error will occur with respect to the actual thrust. Friction coefficient (μ) as on a dry paved road
When the vehicle is running on a road surface with a high coefficient of friction or when braking at a reduced speed with a low deceleration, the pressing force is low and the effect of estimation error is small, but when driving on a road surface with a low coefficient of friction such as a rainy road, a snowy road, or a frozen road In the case of high deceleration braking, the pressing force increases and the estimation error also increases.

At this time, as shown in FIG. 23, another normal wheel whose actual thrust is fed back to perform braking control, and an abnormal wheel which is braked based on the thrust having an estimation error and indicated by smudging. The braking balance with and is lost, and as a result, a yaw moment is generated and the vehicle attitude may change. Therefore, it is necessary to promptly and surely let the driver recognize the failure of the thrust sensor, but the driver may not notice it by turning on or blinking the warning light as a warning means, and the repair may be delayed. There is an unsolved problem that there is.

Therefore, the present invention has been made by paying attention to the unsolved problem of the above-mentioned conventional example, and in a vehicle in which braking force is detected by detecting thrust of a brake friction material against a rotating body rotating with a wheel, An object of the present invention is to provide an electric brake device capable of promptly and reliably recognizing a failure of a thrust force sensor for detecting a thrust force to a driver and urging repair of a failed portion.

[0007]

In order to achieve the above object, an electric brake device according to claim 1 of the present invention includes a brake operation amount detecting means for detecting an operation amount of a brake operating means by a driver, and an input. The electric drive means for controlling the pressing force of the brake friction material against the rotating body that rotates with the wheel according to the braking control amount, the pressing force detection means for detecting the pressing force of the brake friction material, and the brake operation amount detection Target pressing force calculating means for calculating the target pressing force of the brake friction material based on the brake operation amount detected by the means, the target pressing force calculated by the target pressing force calculating means and the pressing force detected by the pressing force detecting means. In an electric brake device including a braking control unit that calculates and outputs a braking control amount for the electric drive unit so that the pressure and the pressure match, the pressing force detection unit Pressing force detection abnormality detecting means for detecting normal, abnormal target pressing force calculating means for calculating an abnormal target pressing force different from the target pressing force, and abnormality target calculated by the abnormal target pressing force calculating means An abnormal braking control means for calculating and outputting a braking control amount for the electric drive means based on the pressing force, and the braking control means when the pressing force detection abnormality detecting means detects an abnormality of the pressing force detecting means. And an abnormal braking control switching means for switching to the abnormal braking control means.

According to the first aspect of the present invention, when the pressing force detection abnormality detecting means detects an abnormality in the pressing force detecting means, the electric drive is performed based on the abnormal target pressing force which is different from the normal target pressing force. The braking control for the means is executed to change the deceleration of the vehicle according to the brake operation amount. The abnormality target pressing force calculating means for calculating the abnormality target pressing force calculates the abnormality target pressing force so that the deceleration of the vehicle becomes higher than that in the normal state when the driver operates the brake pedal. Then, a braking force equal to or greater than the brake operation amount is secured.

According to a second aspect of the present invention, there is provided the electric braking device according to the first aspect, further comprising an estimated pressing force calculating means for calculating an estimated pressing force from a driving state of the electric drive means, and the abnormal braking. The control means is configured to calculate the braking control amount such that the estimated pressing force and the abnormal target pressing force match. According to the second aspect of the present invention, the pressing force corresponding to the brake operation amount by the driver is estimated from the brake friction material position detected from the driving state of the electric drive means, and the estimated pressing force is used as the abnormal target pressing force. Braking control is executed so as to match the pressure.

Further, in the invention according to claim 1, the electric brake device according to claim 3 further comprises an estimated pressing force calculating means for calculating an estimated pressing force from the driving state of the electric drive means, and the abnormal braking is provided. The control means, when an abnormality of the pressing force detection means is detected by the pressing force detection abnormality detection means,
In the abnormal control system in which an abnormality is detected, the braking control amount is calculated so that the estimated pressing force and the target pressing force for abnormality match, and in the normal control system in which no abnormality is detected, the pressing force detection means is used. It is characterized in that the braking control amount is calculated so that the detected pressing force and the abnormal target pressing force match.

According to the third aspect of the present invention, when an abnormality of the pressing force detecting means is detected, the abnormal control system and the normal control system both perform braking based on one abnormal target pressing force corresponding to the brake operation. A controlled deviation is prevented from occurring between a deceleration occurring in an abnormal control system and a deceleration occurring in another normal control system. Further, in the electric brake device according to a fourth aspect of the present invention, in the invention of the second or third aspect, the estimated pressing force calculation means is configured to drive the driving state and the pressing force of the electric drive means when the pressing force detection means is normal. The estimated pressing force is calculated from the drive state of the electric drive means with reference to a control map in which the relationship with

In the invention according to claim 4, when the pressing force detecting means is normal, the relationship between the pressing force and the brake friction material position calculated from the driving state of the electric driving means is stored at any time, and the brake We are creating the latest control map for friction material wear and thermal expansion as well as stiffness change. Furthermore, the electric brake device according to a fifth aspect of the present invention is the electric brake device according to any one of the first to third aspects of the invention, wherein the abnormality target pressing force calculating unit is a unit when the pressing force detecting unit is normal.
It is characterized in that the abnormal target pressing force is calculated with reference to a control map obtained by multiplying a gain showing a relationship between the brake operation amount and the target pressing force by a constant.

According to the fifth aspect of the present invention, the abnormal target pressing force calculating means sets the gain indicating the relationship between the brake operation amount and the normal target pressing force as a constant value which exceeds "1", for example. The target pressing force for abnormality is calculated by multiplying by a constant. Also, in the electric brake device according to a sixth aspect of the present invention, in the invention according to any one of the first to third aspects, the abnormality target pressing force calculating means is configured to set the brake operation amount and the target pressing force when the pressing force detecting means is normal. It is characterized in that the abnormal target pressing force is calculated with reference to a control map offset with respect to a gain showing a relationship with the pressure.

According to the sixth aspect of the present invention, the abnormal target pressing force calculating means offsets the gain indicating the relationship between the brake operation amount and the normal target pressing force to a higher value, for example, so that the abnormal target pressing force is increased. The pressure is calculated. Further, in the electric brake device according to a seventh aspect of the present invention, in the invention according to any one of the first to third aspects, the abnormality target pressing force calculating means is configured to set the brake operation amount and the target pressing force when the pressing force detecting means is normal. It is characterized in that the abnormal target pressing force is calculated with reference to a control map obtained by multiplying an offset obtained by offsetting a gain showing a relationship with the pressure.

According to the seventh aspect of the present invention, the abnormality target pressing force calculating means further increases the gain indicating the relationship between the brake operation amount and the target pressing force in the normal state by, for example, offsetting the gain to a higher value. The target pressure for abnormality is calculated by multiplying by a constant that is a value exceeding ". Further, in the electric brake device according to an eighth aspect, in the invention according to any one of the first to third aspects, the abnormality target pressing force calculating means is
When the offset which is offset up to a certain target pushing force is multiplied by a constant with respect to the gain indicating the relationship between the brake operation amount and the target pushing force when the pushing force detecting means is normal, and when the value exceeds a certain target pushing force. It is characterized in that the abnormal target pressing force is calculated with reference to a control map for returning to the normal gain.

In the invention according to claim 8, the abnormal target pressing force calculation means uses the means of the invention according to claim 7 when the target pressing force is less than the predetermined target pressing force, and when the normal target pressing force is not less than the predetermined target pressing force. The target pressure for abnormality is calculated by returning to the gain of. It is desirable that the predetermined target pressing force is set to a value of the pressing force that causes the vehicle deceleration that results in emergency braking.

Still further, in the electric brake device according to a ninth aspect of the present invention, in the invention according to any one of the fifth to eighth aspects, the abnormality target pressing force calculating means determines the relationship between the brake operation amount and the target pressing force. It is characterized in that it has at least two control maps in which the indicated gains are changed, and the abnormal target pressing force is calculated with reference to different control maps for each braking.

In the invention according to claim 9, at least two control maps having different braking characteristics are provided, and when the driver operates the brake pedal, the abnormal target pressure is calculated based on one of the control maps. To execute braking control. Then, when the pedal operation is released to the position where the brake pedal becomes idle, the control map is switched so that it is switched to the other control map with different brake characteristics and used at the next pedal operation. It will be executed every time.

[0019]

According to the electric brake device of the first aspect, when the abnormality of the pressing force detecting means is detected, the target pressing force for abnormality different from the target pressing force at the normal time is calculated from the target pressing force calculating means. It is configured to switch to the abnormal braking control means that calculates and outputs the abnormal braking control amount based on the above, so that when the driver operates the brake pedal when the pressing force detection means is abnormal, By giving the driver a feeling of pedal operation that causes deceleration of a different vehicle, it is possible to inform the driver that an abnormality has occurred in the pressing force detection means.
It is possible to obtain the effect that the recognition can be performed immediately and surely.

Further, according to the electric brake device of the second aspect, the estimated pressing force calculated by the estimated pressing force calculation unit from the driving state of the electric drive unit and the target pressing force for abnormality different from the target pressing force at the normal time are different. Since the braking control amount is calculated so that the pressure and the pressure match, it is possible to obtain an estimated pressing force according to the amount of brake operation by the driver. By calculating the braking control amount so that the two values match, it is possible to obtain the effect that it is possible to execute the abnormal braking control with high accuracy based on the abnormal target pressing force.

Further, according to the electric brake device of the third aspect, when an abnormality of the pressing force detecting means is detected, both the abnormal control system and the normal control system are made to coincide with the abnormal target pressing force. Since the braking control amount is calculated, it is possible to prevent a change in the vehicle attitude due to the generation of the yaw moment by suppressing the deviation of the braking balance between the abnormal control system and the normal control system. The effect is obtained.

Further, according to the electric brake device of the fourth aspect, the control map showing the relationship between the driving state of the electric drive means and the pressing force is stored at any time when the pressing force detecting means is normal. Therefore, by referring to the control map showing the relationship between the driving state of the electric drive means and the pressing force immediately before the abnormality of the pressing force detecting means is detected, The effect that the highly accurate estimated pressing force that is an approximate value can be calculated is obtained.

Further, according to the electric brake device of the fifth aspect, the abnormality target pressing force calculating means indicates the relationship between the brake operation amount and the target pressing force when the pressing force detecting means is normal. It is configured to refer to a control map obtained by multiplying the gain by a constant. Therefore, by setting this constant to a value exceeding "1", the operation amount of the brake pedal increases, and By increasing the amount of change in the deceleration with respect to, it is possible to obtain the effect that it is possible to transmit to the driver a feeling of pedal operation that is different from that during normal operation.

According to the sixth aspect of the electric brake device, the abnormal target pressing force calculating means indicates the relationship between the brake operation amount and the target pressing force when the pressing force detecting means is normal. Since it is configured to refer to the control map that offsets the gain to a higher value, a certain amount of change occurs in the deceleration of the vehicle according to the amount of brake operation immediately after the driver starts pedal operation. The effect that the feeling of pedal operation different from that in the normal state can be transmitted to the driver is obtained.

Further, according to the electric brake device of the seventh aspect, the abnormality target pressing force calculating means indicates the relationship between the brake operation amount and the target pressing force when the pressing force detecting means is normal. Since the control map obtained by multiplying the gain higher than the gain by a constant by a value exceeding “1” is referred to, the effects of the inventions according to claims 5 and 6 can be obtained. be able to.

Further, according to the electric brake device of the eighth aspect, the abnormality target pressing force calculating means indicates the relationship between the brake operation amount and the target pressing force when the pressing force detecting means is normal. A configuration that refers to a control map in which a value slightly offset up to a predetermined target pressing force with respect to a gain is further multiplied by a constant with a value exceeding “1”, and the gain is restored to a normal value when the predetermined target pressing force is exceeded. Therefore, it is possible to obtain the effect of the invention according to claim 7 when braking in the normal range of vehicle deceleration, and to improve the braking characteristics in the normal state during emergency braking exceeding the normal range of vehicle deceleration. The effect of being able to suppress the deterioration of the controllability due to the brake operation can be obtained by returning.

Still further, according to the electric brake device of the ninth aspect, the abnormality target pressing force calculating means calculates the gain indicating the relationship between the brake operation amount and the target pressing force,
Since each of the control maps has at least two control maps that are changed and the control map that is different for each braking is referred to, the characteristics of the brake operation change each time the brake pedal is operated, so that the driver can be It is possible to avoid getting used to it without noticing the changes in the brake characteristics from time to time, and to reliably convey the feeling of strangeness in the brake operation to the driver who does not recognize the normal brake characteristics. can get.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention, in which 1FL, 1FR, 1R are shown.
L and 1RR are electric brakes that generate braking force on the front left wheel, the front right wheel, the rear left wheel, and the rear right wheel, respectively.

As shown in FIG. 2, each of the electric brakes 1FL to 1RR has a disc rotor 2 formed integrally with each wheel, and a floating caliper 3 for exerting a braking force on the disc rotor 2. Is equipped with. The caliper 3 is a fixed friction pad 4a and a movable friction pad 4b that form a friction member facing each other with the disc rotor 2 in between, and an electric drive unit that controls the pressing force by moving the movable friction pad 4b forward and backward with respect to the disc rotor 2. And an electric drive mechanism 5 and a pressing force sensor 6 for detecting the pressing force of the movable friction pad 4b against the disk rotor 2. As the pressing force sensor 6, a piezoresistive element, a strain gauge type load cell, a strain gauge or the like is used.

Here, the electric drive mechanism 5 is provided with an electric motor 7 composed of a stepping motor as an electric rotary drive source, and a linear conversion mechanism 8 for converting rotational movement of the electric motor 7 into linear movement. There is. This linear conversion mechanism 8
Is a ball screw shaft 9 connected to the rotating shaft 7a of the electric motor 7, a ball nut 11 screwed onto the ball screw shaft 9 via a ball 10, and allows the ball nut 11 to slide to prevent rotation. And an engaging portion 12.

A rotary encoder 13 for detecting the rotation angle and the rotation direction of the electric motor 7 is attached. Further, the ball nut 11 is formed in a cylindrical shape in which the electric motor 7 side is opened and the side opposite to the electric motor 7 side is closed by the end plate 14. In addition, in the engaging portion 12, the cross section of the outer peripheral surface of the ball nut 11 is formed into a polygonal shape such as a triangle or a quadrangle, and the inner peripheral wall of the caliper 3 is also formed into a polygonal shape in accordance with the polygonal shape. The ball nut 11 is prevented from rotating using a rotation preventing member such as a key.

The electric motor 7 of the electric drive mechanism 5 in the electric brake 1 is controlled by the control mechanism 15 as shown in FIG.
Is controlled by. The control device 15 includes a wheel speed sensor 16 that detects a rotation speed of each wheel on which the disc rotor 2 is mounted, a longitudinal acceleration sensor 17 that detects a longitudinal acceleration that occurs in the vehicle, and a yaw rate sensor 18 that detects a yaw rate that occurs in the vehicle. And a brake operation amount sensor 21 for detecting the depression amount of the brake pedal 20 provided with a reaction force generation device 19 for generating a pseudo reaction force with respect to the pedal operation of the driver.

Each detection signal detected by these various sensors 16-18 and 21 and each electric brake 1FL-1RR.
Rotation angle and rotation direction of the electric motor 7 detected by the rotary encoder 13 in FIG.
The pressing force signal detected by R is input to the controller 22 configured by, for example, a microcomputer, and the controller 22 causes the controller 22 to be described later with reference to FIGS. 3, 7, 10, and 6.
The braking control process and the pressing force sensor abnormality detection process are performed, and each electric brake 1FL to 1R is based on each input signal.
The required braking force is calculated in R and the braking force command value is output.

The braking force command value for each of the electric brakes 1FL and 1RR output from the controller 22 is input to the drive circuit 23A, and the drive circuit 23A outputs the electric motors 7 for the electric brakes 1FL and 1RR based on the braking force command value. And a braking force command value for each electric brake 1FR and 1RL output from the controller 22 is input to the drive circuit 23B.
Electric brakes 1FL and 1R based on the braking force command value
The R electric motor 7 is controlled.

The drive circuits 23A and 23B are individually supplied with electric power from the batteries 24A and 24B, and even when one of the batteries 24A and 24B, for example, 24A has an abnormality and the output power is reduced, Normal electric power can be supplied to the drive circuit 23B by the other battery 24B, and the minimum necessary braking force can be secured.

Next, the operation of the first embodiment will be described with reference to the flowcharts showing the braking control processing procedure and the pressing force sensor abnormality detection processing procedure of FIGS. . The controller 22 always executes the braking control process for the electric brakes 1FL to 1RR shown in FIG. In the braking control process, first, in steps S1 to S4, the brake operation amount signal S indicating the depression amount of the brake pedal 20 detected by the brake operation amount sensor 21, and the pressing force sensors 6FL to 6FL.
Pressing forces F _{FL to} F _RR detected by RR, the rotation angle and rotation direction of the electric motor 7 detected by the rotary encoder 13, the vehicle state detected by the wheel speed sensor 16, the longitudinal acceleration sensor 17, and the yaw rate sensor 18. After reading and, the process proceeds to step S5.

In this step S5, the push of FIG.
Different pressure sensor set in the pressure sensor abnormality detection process
Always flag FL_FL~ FL_RRRead the status of
Move to step S6, and the break read in step S1
The operation amount S is the pedal play amount S ₀Judgment whether or not
The result of this determination is S ≦ S₀Is in non-braking state
Then, the process returns to step S1. On the other hand, the judgment result is
S> S₀If it is
The pressing force read in step S5.
Sensor error flag FL_FL~ FL_RRAll represent normal
It is determined whether or not it is reset to "0". This format
The fixed result is "FL_FL~ FL_RRWhen "= 0", each pressing force
It is judged that all the sensors 6FL to 6RR are normal.
Then, the process proceeds to subsequent step S8. On the other hand, the judgment results are
"F" indicating any abnormality of the pressing force sensors 6FL to 6RR
L_FL~ FL_RR= 1 ”, the control that detected an abnormality
Both the control system and the control system judged to be normal are step S
12 for abnormalities shown in FIGS. 7 and 10 described later.
The braking control processing subroutine is executed.

When the pressing force sensors 6FL to 6RR are normal, the braking control process is started in step S8.
Referring to the target pressing force calculation control map showing the relationship between the brake operating amount S and the target pressing force F ^* shown in FIG. 3, the target pressing force F ^* is calculated based on the pedal operating amount read in step S1 ^. To calculate. This target pressing force calculation control map is stored in advance in the memory of the controller 22.

Here, the control map for calculating the target pressing force is
As shown in FIG. 4, the horizontal axis represents the brake operation amount S and the vertical axis represents the target pressing force F ^{*. When} the value of the brake operation amount S is equal to or less than the pedal play amount “S ₀ ”, the target pressing force F ^* is "0" is set as the brake operation amount S increases beyond pedal play amount S ₀ in proportion to increase target pressing force F ^* also.

Then, in step S9, a constant K is added to the absolute value of the difference between the pressing forces F _{FL to} F _RR read in step S2 and the target pressing force F ^* calculated in step S8. The product of the multiplications is calculated as a braking control amount FB for the electric motor 7, and the braking control amount FB is output to the drive circuits 23A and 23B in the subsequent step S10, whereby the electric motor 7 in each of the electric brakes 1FL to 1RR is calculated. Perform normal braking control.

Further, in the subsequent step S11, the pressing forces F _{FL to} F _RR read in step S2 are used for use in the abnormal braking control process after the pressing force sensor abnormality is detected, which will be described later. The relationship between the rotation angle and the rotation direction of the electric motor 7 read in step S3 and the position of the friction pad 4 calculated based on the pitch of the ball screw is stored and updated in the storage table at any time, so that The estimated pressing force calculation control map shown in 5 is updated, and the process returns to step S1.

The pressing force sensor abnormality detection processing procedure shown in FIG. 6 is executed as a timer interruption processing at every predetermined time (for example, 10 msec) with respect to the braking control processing procedure of FIG. 3, and first, step S21 and step S22.
Then, the pressing force sensor 6i (i = FL, FR, RL, RR)
Pressure Fi and brake operation amount sensor 2 detected by
After reading the brake operation amount signal S representing the depression amount of the brake pedal 20 detected in step 1, the process proceeds to step S23.

In step S23, the pressing force sensor 6
When i is short-circuited, the power supply voltage is applied to the output signal and the pressing force Fi becomes the maximum value.
By determining whether or not the pressing force Fi read in 1 exceeds a predetermined value Fhigh, an abnormality of the pressing force sensor 6i due to a short circuit is detected. That is, this determination result is "F
When i ≧ Fhigh ”, the pressing force sensor 6i is determined to be abnormal due to a short circuit. Therefore, the process proceeds to step S24, and the pressing force sensor abnormality flag FLi of the pressing force sensor 6i determined to be abnormal is set to“ 1 ”. Then, the process returns to step S21. On the other hand, when the result of the determination in step S23 is "Fi <Fhigh", it is determined that there is no abnormality due to a short circuit, and the process proceeds to step S25.

In this step S25,
The brake operation amount S read in 22 is the pedal operation amount S₀To
It is determined whether or not it exceeds, and the determination result is S ≦ S.₀so
If there is, it is determined that the vehicle is in the non-braking state, and the process proceeds to step S21
Return. On the other hand, the determination result is S> S ₀When is the braking state
Then, the process proceeds to step S26. This station
In step S26, when the pressing force sensor 6i is disconnected,
Since the output signal is zero, it is read in step S21.
By determining whether the pressing force Fi is “0”,
An abnormality of the pressing force sensor 6i due to the disconnection is detected. Immediately
When the result of this judgment is "Fi = 0", the pressing force
The sensor 6i is judged to be abnormal due to disconnection, so
Up S24, pressing force sensor abnormality flag FLi
Is set to "1", and then step S21 is performed again.
Return to. On the other hand, the determination result of step S26 is “Fi>
When it is 0 ”, it is judged that there is no abnormality due to disconnection.
Then, the process proceeds to step S27.

In this step S27, as in step S8 of the braking control process, based on the pedal operation amount S read in step S22, referring to the target pressing force calculation control map of FIG. transition from calculate the pressing force F ^* in step S28, compares the pressing force Fi and the target pressing force F ^* and calculates a deviation ΔFi comprising an absolute value of the difference.
In a succeeding step S29, it is determined whether or not the deviation ΔFi exceeds a predetermined value Flimit to detect an abnormality in the pressing force sensor 6 due to an indefinite output of the pressing force sensor or a change in gain. That is, this determination result is "Δ
When Fi ≧ Flimit ”, the pressing force sensor 6i
It is determined that the output is indeterminate or abnormal due to a change in gain, and the process proceeds to step S24. On the other hand, step S29
If the result of the determination is “ΔFi <Flimit”, there is no abnormality due to indefinite output or change in gain, and it is determined to be normal. Therefore, after shifting to step S30, the pressing force sensor abnormality flag FLi is set. After resetting to "0", the process returns to step S21.

Then, the above-mentioned processing is performed by each pressing force sensor 6FL-
After repeating all 6RR, the timer interrupt process is terminated and the process returns to the braking control process of FIG. Next, FIG.
When it is determined in step S7 of the braking control process shown in FIG. 7 that the states of the pressing force sensor abnormality flags FL FL to _{FL RR} are “1”, the abnormality control system executed after shifting to step S12 is executed. Regarding the subroutines for the abnormal braking control processing and the abnormal braking control processing of the normal control system,
This will be described with reference to FIGS. 7 and 10.

The pressing force sensor 6F having the abnormality shown in FIG.
In the subroutine of the braking control process for abnormality in any of the abnormality control systems of L to 6RR, first, in step S31, the actual pressing force in the normal state stored in the controller 22 in step S11 of FIG. Referring to the pressing force calculation control map of FIG. 5 showing the relationship with the position of the friction pad 4, as shown in FIG. 8, the rotation angle and rotation direction of the electric motor 7 read in step S3, and the ball screw The estimated pressing force F _E is calculated from the position of the friction pad 4, which is calculated based on the pitch.

Then, in step S32, the gain of the control map showing the relationship between the pre-stored normal pedal operation amount S and the target pressing force F ^* is changed as shown in FIG. The abnormal target pressing force F _F ^* is calculated based on the pedal operation amount read in step S1 with reference to the abnormal target pressing force calculation control map.

This abnormal target pressing force calculation control map is
As shown in FIG. 9, when the brake operation amount S is equal to or less than the pedal play amount "S ₀ ", the target pressing force under normal conditions is also "0".
Therefore, when the brake operation amount S increases from this state, the abnormal target pressure is set to be always higher than the normal target pressure that increases in proportion to this. Subsequently, the process proceeds to step S33, and the difference between the estimated pressing force F _E calculated in step S31 and the abnormality target pressing force F _F ^* calculated in step S32 is multiplied by a gain constant K to obtain an electric value. It is calculated as the braking control amount FB ′ for the motor 7, and the braking control amount F is calculated in the subsequent step S34.
By outputting B ′ to the drive circuits 23A and 23B, the braking control for abnormality is executed for the electric motor 7, and the process returns to step S1.

Further, in the subroutine of the braking / braking control process for abnormality in the normal control system of any of the normally operating pressing force sensors 6FL to 6RR shown in FIG. 10, first, in step S41, the steps S32 and Similarly, referring to FIG. 5, the abnormal target pressing force F _F ^* is calculated. Then, the process proceeds to step S42, and the difference between the pressing force F detected in step S2 and the abnormal target pressing force F _F ^* calculated in step S41 multiplied by a gain constant K is used as the electric motor 7 Is calculated as a braking control amount FB ′ for the electric motor 7 and the braking control amount is output to the drive circuits 23A and 23B in the subsequent step S43 to execute the abnormal braking control for the electric motor 7, Return to.

In the processing of FIG. 3, the processing of step S5 corresponds to the pressing force detection abnormality detecting means, the processing of step S7 corresponds to the abnormal braking control switching means, and step S12.
Process corresponds to the braking control means for abnormality. Further, the processing procedure of FIG. 6 corresponds to the pressing force detection abnormality detecting means. Further, the processing of FIG. 7 corresponds to the braking control means for abnormality,
Of these, step S31 corresponds to the estimated pressing force calculation means,
Step S32 corresponds to the abnormal target pressing force calculation means. Further, the processing of FIG. 10 corresponds to the braking control means for abnormality, and step S41 therein corresponds to the target pressing force calculation means for abnormality.

Therefore, in the pressure sensor abnormality detection process of FIG. 6 which is executed by the controller 22, a disconnection, a short circuit, an output indefiniteness or a gain is detected on the basis of the detection signal from the pressure sensor 6 of each of the electric brakes 1FL to 1RR. When no abnormality due to a change or the like is detected, the pressing force sensor abnormality flags FL _{FL to FL RR} are reset to “0”.

At this time, when there is no pedal operation by the driver, the non-braking state is continued, and in this state, the friction pad 4 is at a predetermined position separated from the disc rotor 2. When the pedal operation is started, the controller 22 executes the braking control under normal conditions, and calculates the braking control amount FB so that the pressing force F and the target pressing force F ^* match. This braking control amount FB is the drive circuits 23A and 23.
By being output to the electric motor 7 via B, the electric motor 7 is rotationally driven, for example, in the clockwise direction, and the rotation shaft 7
The ball screw shaft 9 is also driven to rotate clockwise through a,
The ball nut 11, which is screwed with the ball screw shaft 9, is prevented from rotating by the engagement with the inner peripheral wall of the caliper 3 and is allowed to move only linearly. By pressing the friction pad 4 against the disc rotor 4, a predetermined control is performed. Powered.

At this time, the pressing forces F _{FL to} F _RR obtained by the pressing force sensors 6FL to 6RR and the position of the friction pad 4 calculated based on the rotation angle and the rotating direction of the electric motor 7 and the pitch of the ball screw. The storage table indicating the relationship is updated, and thereby the pressing force calculation control map of FIG. 5 is updated. Therefore, the pressing force calculation control map is constantly updated to the one corresponding to wear and thermal expansion.

When the brake operation is released, the electric brake 7 is driven to rotate in the counterclockwise direction to follow the procedure opposite to that at the start of braking, so that the friction pad 4 is separated from the disc rotor 2. Release the braking force.
Here, a wire break, short circuit, or
Alternatively, when an abnormality occurs due to indefinite output or gain change, the pressing force abnormality flag FL _{FL to FL RR} is set to "1" in the pressing force sensor abnormality detection process, and the abnormality is detected in the controller 22 in step S7. Both the control system and the control system determined to be normal are switched from normal braking control to abnormal braking control.

At this time, when the driver operates the brake pedal, the pressing force sensor 6FL which has detected an abnormality is detected.
In any of the abnormal control systems of 6RR, step S31
Then, based on the estimated pressing force calculation control map of FIG. 5 showing the relationship between the position of the friction pad 4 and the pressing force updated immediately before the abnormality is detected, the estimated pressing force is calculated from the current position of the friction pad 4. Calculate F _E. Since this control map is updated with the wear and thermal expansion of the friction pad and the change in rigidity, it is possible to estimate the approximate value of the actual pressing force.

Next, in step S32, based on the abnormal control map stored in the controller 22 in advance, the gain being the brake characteristic in the normal state showing the relationship between the pedal operation amount and the target pressing force is changed. , The target pressure for abnormality F _F ^* is calculated from the pedal operation amount. The control map for this abnormality uses the target pressing force F _F ^* according to the brake operation amount in order to secure a braking force equal to or greater than the brake operation by the driver ^.
The gain is changed so that is calculated higher than in the normal state.

Then, in step S33, the braking control amount FB 'is calculated so that the estimated estimated pressing force F _E and the abnormal target pressing force F _F ^* coincide with each other, and the braking control amount FB' is calculated via the drive circuits 23A and 23B. The braking force can be obtained by outputting to the electric motor 7. In addition, in any normal control system of the pressing force sensors 6FL to 6RR that is determined to be normal,
The braking control amount FB ′ is calculated so that the pressing force actually measured by the pressing force sensor 6 matches the abnormal target pressing force F _F ^*, and is output to the electric motor 7 via the drive circuits 23A and 23B. .

[0059] Thus, the abnormality control system and normal control system are both because they are controlled based on the normal state of the target pressing force F ^* different anomaly target pressing force F _F ^*, good prevent displacement of the braking balance While maintaining the excellent controllability, the driver can recognize the abnormality of the electric brake immediately and surely from the pedal operation due to the brake characteristic different from the normal state.

Next, a second embodiment of the present invention will be described with reference to FIGS. 11 and 12. The second embodiment is a modification of the first embodiment described above, in which the brake characteristic when the abnormal braking control is executed when the pressing force sensor 6 is abnormal is changed. That is, in the second embodiment,
As shown in FIG. 11, when the pressing force sensor 6 is normal, the gain indicating the relationship between the brake operation amount and the target pressing force is multiplied by a constant that is a constant that is a value exceeding "1", and the abnormal target pressing force is increased. Abnormal target pressing force F with reference to the pressure calculation control map
Except that it is configured to calculate _F ^* , it has the same configuration and control processing means as in the first embodiment, and a detailed description thereof will be omitted.

In the abnormal target pressing force calculation hand control map of FIG. 11, the gain for normal target pressing force calculation is "1".
When the brake operation amount S is equal to or less than the pedal play amount “S ₀ ”, the abnormality target pressing force F _F
^* Also becomes "0", and if the brake operation amount S increases from this state, the abnormal target pressing force also increases at a higher rate than in the normal state.

Here, the constant by which the gain is multiplied is preferably set as follows. That is, FIG. 12 shows the relationship between the pedal feel and controllability of the brake operation with respect to the amount of change in deceleration. The amount of change in deceleration is 0
It is divided into 5 stages, and the evaluation of the pedal feel and control of the brake operation is also divided into 0 to 5 stages. A rating of "3" or higher is a level that does not matter, and good control is achieved with a normal pedal feel. This is an area that can be enjoyed. In this relationship, when the amount of change in the deceleration gradually increases from 0 to 5, the pedal feel first falls below the score "3", and then the controllability also falls below the score "3". Have already been proved by experiments by the inventors. Therefore, according to this characteristic, there is a range of deceleration change amount that makes it possible to give the driver a feeling of braking different from that during normal operation, while maintaining good controllability in brake operation. Therefore, the constant may be set so that the deceleration of the vehicle changes within this range.

As described above, the gain at the normal time is set to "1" within the range of the deceleration change amount, which makes it possible to give the driver a brake feeling different from the normal time while maintaining the good controllability. Since the control map that is multiplied by a constant with a constant that exceeds the value is referenced, immediately after the driver starts the operation,
The amount of change in deceleration is small, and good controllability is maintained with a pedal feel that is close to normal. However, when the amount of brake operation increases and the amount of change in deceleration increases, the driver gradually increases the pedal feel, which is different from that in the normal time.
The abnormality of the pressing force sensor 6 can be perceived.

Next, a third embodiment of the present invention will be described with reference to FIG. This third embodiment is the same as the first embodiment described above.
In the above embodiment, the braking characteristics when the abnormal braking control is executed when the pressing force sensor is abnormal are changed. That is, in the third embodiment, as shown in FIG. 13, refer to a control map that is offset higher than the gain indicating the relationship between the brake operation amount and the target pressing force when the pressing force detection means is normal. Then, it has the same configuration and control processing means as those of the first embodiment except that it is configured to calculate the abnormal target pressing force, and a detailed description thereof will be omitted.

The abnormal target pressing force calculation hand control map of FIG. 13 sets a gain for abnormal target pressing force calculation, which is obtained by offsetting the gain for normal target pressing force calculation to a higher level, and sets a brake operation. When the amount S is less than the pedal play amount "S ₀ ", the abnormal target pressing force F _F ^* is maintained at "0", and when the brake operation amount S exceeds the pedal play amount "S ₀ " The target pressing force F _F ^* becomes the offset amount “F _O ” with respect to the normal state, and if the brake operation amount S increases from this state, the abnormal target pressing force F _F ^* will be at the same rate as in the normal state ^.
Is also set to increase.

As described above, the gain in the normal state is offset to a higher value within the range of the deceleration change amount that makes it possible to give the driver a pedal feeling different from that in the normal state while maintaining good controllability. As it is configured to refer to the control map, immediately after the driver starts pedal operation, a deceleration different from the normal state occurs, and the driver immediately feels the pedal force different from that in the normal state. The abnormality of the sensor 6 can be recognized.

Next, a fourth embodiment of the present invention will be described with reference to FIG. The fourth embodiment is the same as the first embodiment described above.
In the above embodiment, the braking characteristics when the abnormal braking control is executed when the pressing force sensor is abnormal are changed. That is, in the fourth embodiment, as shown in FIG. 14, a gain which is higher than the gain indicating the relationship between the brake operation amount and the target pressing force when the pressing force detecting means is normal may be further offset. Except that it is configured to calculate the abnormal target pressing force by referring to the control map that is multiplied by a constant that is a value that exceeds “1”,
The configuration and the control processing means are the same as those in the above embodiment, and detailed description thereof will be omitted.

In the abnormal target pressing force calculation hand control map of FIG. 14, the gain for normal target pressing force calculation is offset slightly higher, and is further multiplied by a constant with a constant value exceeding "1". The gain for calculating the target pressure for abnormality is set, and the brake operation amount S is the pedal play amount "S ₀ ".
When the following is true, the abnormal target pressing force F _F ^* is maintained at “0”, and when the brake operation amount S exceeds the pedal play amount “S ₀ ”, the abnormal target pressing force F _F ^* is compared with the normal state. The offset amount becomes “F _O ”, and when the brake operation amount S increases from this state, the abnormal target pressing force also increases at a higher rate than in the normal state.

As described above, the gain in the normal state is offset to a higher value within the range of the deceleration change amount, which makes it possible to give the driver a pedal feeling different from that in the normal state while maintaining good controllability. Since it is configured to refer to the control map that is a constant multiple of the value that exceeds “1”, a deceleration different from the normal time occurs immediately after the driver starts pedal operation. Therefore, it is possible to immediately transmit to the driver a pedal feeling different from that in the normal state. After that, as the amount of brake operation increases, the amount of change in deceleration also increases. Therefore, the driver can perceive an abnormality in the pressing force sensor 6 with a pedal feeling that gradually increases and is different from that in a normal state.

Next, a fifth embodiment of the present invention will be described with reference to FIG. The fifth embodiment is the same as the first embodiment described above.
In the above embodiment, the braking characteristics when the abnormal braking control is executed when the pressing force sensor is abnormal are changed. That is, in the fifth embodiment, as shown in FIG. 15, when the pressing force detection means is in a normal state, the gain indicating the relationship between the brake operation amount and the target pressing force is up to a predetermined target pressing force. , A higher offset value is further multiplied by a constant value that exceeds “1”, and returns to the normal gain when the pressure exceeds this predetermined target pressure. Except that it is configured to calculate the target pressing force, it has the same configuration and control processing means as in the first embodiment, and a detailed description thereof will be omitted.

The abnormal target pressing force calculation hand control map of FIG. 15 further exceeds "1" when the gain for normal target pressing force calculation is slightly offset up to a predetermined target pressing force. The gain is set so as to return to the normal gain when the predetermined target pressing force is exceeded by multiplying by a constant that is a value, and when the brake operation amount S is equal to or less than the pedal play amount "S ₀ ". The abnormal target pressing force F _F ^* is maintained at “0” at a certain time, and when the brake operation amount S exceeds the pedal play amount “S ₀ ”, the abnormal target pressing force F _F ^* is an offset amount from the normal state. It becomes “F _O ”, and the brake operation amount S increases from this state, and when the pressure exceeds a certain predetermined pressing force, the gain is restored to the normal value.

FIG. 16 shows the relationship between vehicle deceleration and frequency of use. If, for example, up to 99% of the total frequency of use in vehicle deceleration is set as the normal range, vehicle deceleration exceeding it means high G braking in an emergency, and accurate brake control during high G braking in this emergency. Is the most important. Therefore, since the braking characteristic in the normal state is required for the emergency braking exceeding the normal range, it is desirable to set the pressing force for generating the vehicle deceleration that causes the emergency braking as the predetermined target pressing force.

In this way, if the frequency of use of the vehicle deceleration is, for example, up to 99% in the normal range, deceleration exceeding that frequency will result in emergency braking. Therefore, a certain predetermined target pressing force has a predetermined threshold value. By determining the target pressing force, a deceleration different from the normal state is generated immediately after the driver starts pedal operation. Therefore, the driver immediately feels that the pressing force sensor 6 is abnormal due to a pedal feeling different from the normal state. Can be perceived. Further, during emergency braking in which the brake operation amount increases and the deceleration exceeds the normal range, the normal braking characteristics can be obtained and accurate controllability can be secured.

Next, a sixth embodiment of the present invention will be described with reference to FIGS. In the sixth embodiment, in the first embodiment described above, the braking characteristic when the abnormal braking control is executed when the pressing force sensor 6 is abnormal is changed for each braking. That is, in the sixth embodiment, as shown in FIG. 17, there are two control maps in which the gain showing the relationship between the brake operation amount and the target pressing force is changed, and a control map different for each braking is provided. With reference to, the configuration is similar to that of the first embodiment, except that the abnormality target pressing force is calculated.

Further, as shown in FIG. 17, the braking control process executed by the controller 22 has a configuration in which steps S51 to S56 are added to the process of FIG. 5 in the above-described first embodiment. The same parts as those in the process of 5 are designated by the same reference numerals, and the detailed description thereof will be omitted. Here, if it is determined in step S6 whether or not the brake operation amount S exceeds the pedal play S _0, and if the determination result is “S> S ₀ ”, it is determined that braking is started, and then step In step S51, the braking flag F _B is set to "1", and then in step S7. On the other hand, when the result of this determination is “S ≦ S ₀ ”, it is determined that non-braking is performed, the process proceeds to step S52, and step S5 is performed.
It is determined whether the braking flag F _B of 1 is set to "1". If the result of this determination is "0", it means that no braking was applied from the beginning, and the process returns to step S1. If the result of determination in step S52 is set to "1", it means that the braking is completed, and the following step S53.
Then, the braking flag F _B is reset to “0”, and the process proceeds to step S54.

In this step S54, FIG.
And, as shown in FIG. 20, at the time of the previous abnormality braking control, M
Determine which of AP0 and MAP1 is referenced,
When this determination result is "MAP = 1", the process proceeds to step S55, MAP0 is prepared in place of MAP1, and then the process returns to step S1. On the other hand, the determination result is "MAP
= 0 ”, the process proceeds to step S56 and MAP
After preparing MAP1 instead of 0, the process returns to step S1.

Next, in step S7, each pressing force sensor 6
In the subroutine of the braking control process for abnormality executed after shifting to step S12 when an abnormality is detected in any of _{FL to} 6RR and the pressing force sensor abnormality flag FL FL to _{FL RR} is set to "1" , Steps S61 to S63 are added to the abnormal control system shown in FIG. 18, and steps S71 to S63 are added to the normal control system shown in FIG.
The configuration is such that step S73 is added, and portions corresponding to the processing of FIGS. 9 and 12 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the control processing for abnormality in the abnormality control system shown in FIG. 18, first, the estimated pressing force F _E is calculated in step S31, and then MA is determined based on the determination result in step S54.
It is determined which MAP, P0 or MAP1, is prepared. When this determination result is “MAP = 1”,
Moving to step S62, the MA shown by the solid line in FIG.
The abnormal target pressing force F _F ^* is calculated with reference to P1. On the other hand, when the determination result is “MAP = 0”, the process proceeds to step S63 and the MAP illustrated by the dashed line in FIG.
The target pressure for abnormality F _F ^* is calculated with reference to 0. Also,
Also in the control process for abnormality in the normal control system shown in FIG. 20, as in the case of the abnormal control system, steps S71 to
Through step S73, the abnormal target pressing force F _F ^* is calculated.

In the sixth embodiment, as shown in FIG. 19, there are two different abnormal target pressing force calculation hand control maps (MAP0, MAP1). Here, the target pressing force calculation control map when the pressing force sensor is normal is used for MAP0, and the abnormal target pressing force calculation control map in the fifth embodiment is used for MAP1.
The detailed description thereof will be omitted. Here, when the driver operates the brake when the pressing force sensor is in an abnormal state, for example, when the braking control is executed based on the control MAP1, the driver immediately detects an abnormality in the pressing force sensor 6 due to the brake characteristic in the fifth embodiment. The occurrence can be perceived. When the brake operation is released, the controller 22
The other control MAP0 is switched to prepare for the next braking control for abnormality. Here, when the brake pedal is re-operated, the abnormal braking control is executed based on the control MAP0, and the normal braking characteristic is obtained. Therefore, it is necessary to realize a braking characteristic that is clearly different from the previous braking characteristic. You can By executing such control map switching operation each time the pedal operation is released, it is possible to avoid the driver from becoming accustomed to a single change in the brake characteristics and to recognize the brake characteristics during normal operation. It is possible to reliably transmit the feeling of the brake operation that makes the occurrence of an abnormality even to a driver who is not present.

In the above first to sixth embodiments, the case where the pressing force sensor abnormality detection processing procedure is configured to be processed by the timer interruption for every predetermined time with respect to the braking control processing procedure has been described. The present invention is not limited to this, and the pressing force sensor abnormality detection processing procedure may be included in the braking control processing procedure of the main flowchart for processing.

Further, in the above first to sixth embodiments, the case where the ball screw is used as the linear conversion mechanism 8 has been described. However, the present invention is not limited to this, and a normal screw shaft and a screw screw It is also possible to apply a nut that operates with a pinion that is rotationally driven by an electric motor, and a rack that meshes with the pinion.

Further, in the first to sixth embodiments, the front left electric brake 1FL and the rear right electric brake 1R are provided.
R, front right electric brake 1FR and rear left electric brake 1R
The case where L and L are controlled by individual control systems has been described, but the present invention is not limited to this, and individual control systems are used for front and rear, and electric brakes 1FL to 1RR.
May be controlled independently of each other.

Further, in the above-described first to sixth embodiments, once an abnormality such as a short circuit, a wire breakage, an output indefiniteness or a gain change is detected in the pressing force sensor abnormality detection processing, the braking control for abnormality is switched to. Although the case has been described above, the present invention is not limited to this, and it may be determined to be abnormal when abnormality detection has reached a predetermined number of times, and switching to abnormality braking control may be performed.

Furthermore, in the above-described first to sixth embodiments, the case where the abnormality of the pressing force sensor is detected and both the abnormal control system and the normal control system are switched to the abnormal braking control has been described. However, the present invention is not limited to this, and the braking control at the normal time may be executed only in the normal control system.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing an electric brake.

FIG. 3 is a flowchart showing an example of a braking control processing procedure executed by the controller according to the first embodiment of the present invention.

FIG. 4 is a control map showing a relationship between a brake operation amount and a target pressing force according to the first embodiment of the present invention.

FIG. 5 is a control map showing the relationship between the friction pad position and the pressing force in the first embodiment of the present invention.

FIG. 6 is a flowchart showing an example of a pressing force sensor abnormality detection processing procedure executed by the controller according to the first embodiment of the present invention.

FIG. 7 is a flowchart showing an example of an abnormal braking control processing procedure of an abnormal control system executed by the controller according to the first embodiment of the present invention.

FIG. 8 is a control map showing the relationship between the friction pad position and the pressing force for calculating the estimated pressing force in the first embodiment of the present invention.

FIG. 9 is a control map showing a relationship between a brake operation amount and an abnormal target pressing force according to the first embodiment of the present invention.

FIG. 10 is a flowchart showing an example of an abnormal braking control process procedure of a normal control system executed by the controller according to the first embodiment of the present invention.

FIG. 11 is a control map showing a relationship between a brake operation amount and an abnormal target pressing force according to the second embodiment of the present invention.

FIG. 12 is a sensory score table of pedal feel and controllability of a brake operation with respect to an amount of change in deceleration, based on experimental results in the second embodiment of the present invention.

FIG. 13 is a control map showing a relationship between a brake operation amount and an abnormal target pressing force according to the third embodiment of the present invention.

FIG. 14 is a control map showing a relationship between a brake operation amount and an abnormal target pressing force according to the fourth embodiment of the present invention.

FIG. 15 is a control map showing a relationship between a brake operation amount and an abnormal target pressing force according to the fifth embodiment of the present invention.

FIG. 16 is a use frequency distribution diagram of deceleration during brake operation in the fifth embodiment of the present invention.

FIG. 17 is a flowchart showing an example of a braking control processing procedure executed by a controller according to the sixth embodiment of the present invention.

FIG. 18 is a flowchart showing an example of an abnormal braking control processing procedure of an abnormal control system executed by a controller according to a sixth embodiment of the present invention.

FIG. 19 is a control map showing a relationship between a brake operation amount and an abnormal target pressing force according to the sixth embodiment of the present invention.

FIG. 20 is a flowchart showing an example of an abnormal braking control process procedure of a normal control system, which is executed by the controller according to the sixth embodiment of the present invention.

FIG. 21 is a graph showing a relationship between a brake operation amount and a pressing force with respect to a piston position in a conventional example.

FIG. 22 is a graph showing a relationship between an estimated pressing force and a brake operation amount and a piston position in a conventional example.

FIG. 23 is a diagram showing a deviation of a braking balance in a vehicle, which is caused by an error in an estimated pressing force in a conventional example.

[Explanation of symbols]

2 disk rotor 3 calipers 4a Fixed friction pad 4b Movable friction pad 5 Electric drive mechanism 6 Pressure sensor 7 Electric motor 8 Linear conversion mechanism 9 Ball screw shaft 11 ball nuts 13 rotary encoder 15 Control mechanism 20 brake pedal 21 Brake operation amount sensor 22 Controller

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tsuyoshi Kawada             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation F-term (reference) 3D046 BB01 CC06 HH02 HH21 HH26                       HH36 HH51 JJ01 LL14 MM06                       MM15                 3D048 BB03 CC49 HH18 HH58 HH61                       HH66 HH70 RR01 RR02 RR25                       RR35                 3D049 BB02 CC07 HH45 HH47 HH51                       RR10

Claims (9)

[Claims] 1. A brake operation amount detecting means for detecting an operation amount of a brake operating means by a driver, and an electric motor for controlling a pressing force of a brake friction material against a rotating body rotating with a wheel according to an input braking control amount. A driving means, a pressing force detecting means for detecting the pressing force of the brake friction material, and a target pressing force calculation for calculating a target pressing force of the brake friction material based on the brake operation amount detected by the brake operation amount detecting means. Means and braking control means for calculating and outputting a braking control amount for the electric drive means so that the target pressing force calculated by the target pressing force calculation means and the pressing force detected by the pressing force detection means match. In an electric brake device comprising: a pressing force detection abnormality detecting means for detecting an abnormality of the pressing force detecting means, and an abnormal target pressing force different from the target pressing force. An abnormal target pressing force calculating means for outputting, and an abnormal braking control means for calculating and outputting a braking control amount for the electric drive means based on the abnormal target pressing force calculated by the abnormal target pressing force calculating means. And an abnormal braking control switching unit that switches from the braking control unit to the abnormal braking control unit when the pressing force detection abnormality detection unit detects an abnormality in the pressing force detection unit. . 2. An estimated pressing force calculating means for calculating an estimated pressing force from the driving state of the electric drive means, wherein the abnormality braking control means has the estimated pressing force and the abnormality target pressing force coincident with each other. The electric brake device according to claim 1, wherein the brake control amount is calculated as described above. 3. An estimated pressing force calculation means for calculating an estimated pressing force from the driving state of the electric drive means, wherein the abnormality braking control means is the pressing force detection abnormality detection means of the pressing force detection means. When an abnormality is detected, in the abnormality control system in which the abnormality is detected, the braking control amount is calculated so that the estimated pressing force and the abnormality target pressing force match, and the normal control system in which the abnormality is not detected 2. The electric brake device according to claim 1, wherein the braking control amount is calculated so that the pressing force detected by the pressing force detection means and the abnormality target pressing force match. 4. The estimated pressing force calculating means refers to the control map, which updates the relationship between the driving state of the electric drive means and the pressing force at any time when the pressing force detecting means is in a normal state, and refers to the electric drive. The electric brake device according to claim 2 or 3, wherein the estimated pressing force is calculated from the driving state of the driving means. 5. The abnormal target pressing force calculating means refers to a control map obtained by multiplying a gain showing a relationship between a brake operation amount and the target pressing force when the pressing force detecting means is normal by a constant. The electric brake device according to any one of claims 1 to 3, wherein the target pressure for abnormality is calculated. 6. The abnormal target pressing force calculation means refers to a control map offset with respect to a gain indicating a relationship between a brake operation amount and the target pressing force when the pressing force detection means is normal. The electric brake device according to any one of claims 1 to 3, wherein the abnormal target pressing force is calculated. 7. The abnormal target pressing force calculation means is a control in which a value obtained by offsetting a gain showing a relationship between a brake operation amount and the target pressing force when the pressing force detection means is normal is multiplied by a constant. The electric brake device according to any one of claims 1 to 3, wherein the abnormal target pressing force is calculated with reference to a map. 8. The abnormal target pressing force calculating means offsets to a certain target pressing force with respect to a gain indicating the relationship between the brake operation amount and the target pressing force when the pressing force detecting means is normal. 4. The abnormal target pressing force is calculated with reference to a control map that multiplies an object by a constant and returns to a normal gain when the pressure exceeds a certain target pressing force. The electric brake device according to any one of claims. 9. The abnormal target pressing force calculation means calculates a gain indicating a relationship between a brake operation amount and the target pressing force,
9. The electric motor according to claim 4, wherein the abnormality target pressing force is calculated by having at least two control maps that are changed, and referring to different control maps for each braking. Brake device.