JP6289966B2 - Electric brake device - Google Patents

Description

  The present invention relates to an electric brake device in an automobile, and more particularly to control thereof.

The following proposals have been made as a method for controlling the electric brake device.
A proposal is made to reduce the pad clearance when the accelerator pedal is turned off, thereby speeding up the response of the braking force at the start of braking (Patent Document 1).
Proposal to widen pad clearance and reduce drag resistance according to vehicle speed and accelerator pedal opening (Patent Document 2).
A proposal for an electric linear actuator using a screw mechanism and an electric motor (Patent Document 3).

Japanese Patent No. 4166336 Japanese Patent No. 4495621 JP 2006-194356 A

In a friction brake that applies braking by the sliding resistance between the friction pad and the brake rotor, it is required to provide a clearance larger than a predetermined clearance between the friction pad and the brake rotor in order to reduce drag torque. On the other hand, when this clearance is widened, there is a problem that the response speed when the brake is applied from the non-braking state decreases.
For example, in the method of Patent Document 1, when the pad clearance is reduced when the accelerator pedal is not operated, for example, when the driver operates to maintain a constant speed, the accelerator pedal is frequently turned ON / OFF, so that the electric brake Unnecessary operations occur in the device, and there is a concern that the operating noise will deteriorate and the power consumption will increase. Further, the drag torque is increased by reducing the clearance each time the accelerator pedal is turned off, which may lead to deterioration of fuel consumption / electricity cost mainly at high speed.

  In the method of Patent Document 2, a method of reducing the drag torque by increasing the pad clearance mainly during high speed traveling has been proposed. However, by increasing the pad clearance, braking is urgently required from high speed traveling. In some cases, the response time of the brake may be delayed. In the electric brake device using the motor as in Patent Document 3, the main factor of the response delay is the moment of inertia of the motor. If the moment of inertia is reduced, the torque is inevitably reduced, which is a trade-off in motor design. . Moreover, the feeling of brake operation may be deteriorated by the operation sound generated by rapidly accelerating the motor.

  The present invention solves the above-mentioned problems, and can reduce the influence of the inertia of the motor, enabling quick braking force, improved driver operation feeling, large torque motor design, and reduced power consumption. Another object of the present invention is to provide an electric brake device that can reduce an operation sound generated by torque fluctuation.

The electric brake device according to the present invention includes a brake rotor 4 that rotates integrally with the wheel 3, a friction pad 5 that contacts the brake rotor 4 to generate a braking force, an electric motor 6, and an output of the motor 6. A transmission mechanism 7 for converting the pressing force of the friction pad 5, a brake force command means 13 a for detecting the operation amount of the brake operation means 13 and instructing it as a target brake force, and the motor 6 according to the command of the target brake force In the electric brake device having the brake control device 2 for driving
In the brake control device 2,
In the initial period of the process in which the brake command value of the brake force command means 13a increases from zero, a dead zone is set in which the friction pad 5 does not contact the brake rotor 4 and maintains the brake force at zero. Dead zone setting means 17;
In the dead zone, the motor 6 is driven such that the friction pad 5 does not contact the brake rotor 4 and the braking force is zero, and the motor 6 is rotating at an angular velocity equal to or greater than a predetermined value. A preceding drive means 18 is provided;
It is characterized by that.
The brake force command means 13a is, for example, a stroke sensor provided on a pedal which is the brake operation means 13 provided in the vehicle. The dead zone is a range corresponding to play normally provided in the brake pedal, and is set to an appropriate value.
The predetermined section is, for example, a range corresponding to play generally provided in a brake pedal.

  According to this configuration, a dead zone is provided in the brake control device 2 that drives the motor 6 in accordance with the brake command value of the brake force command unit 13a. In this dead zone, no brake force is generated based on the operation of the brake operation unit 13. In the region, the motor 6 is accelerated in advance to an angular velocity equal to or greater than a predetermined value. As a result, the influence of the inertia of the motor 6 can be reduced, and the braking force can be quickly exerted, so that the operation feeling of the driver is improved. In addition, since a decrease in response speed due to an increase in inertia of the motor 6 can be compensated, a design using the motor 6 having a large torque becomes possible, and power consumption can be reduced. Sudden output fluctuations of the motor 6 are also suppressed, so that the maximum load on the power supply is reduced. Furthermore, it is possible to reduce the operating noise generated by torque fluctuation.

In the present invention, when the brake operating means 13 is operated from a brake command value of zero or less, the time until the moment when the brake command value of the brake force command means 13a escapes from the dead zone and the brake force starts to be generated or immediately before. The brake control device 2 is provided with an escape time estimation means 19 for estimating the dead zone escape time, and the preceding drive means 18 generates a braking force when the dead zone escape time estimated by the escape time estimation means 19 has elapsed. The motor 6 may be controlled to start.
By estimating the dead zone escape time, it is possible to make the dead zone as large as possible within a range where the braking force is not unexpectedly generated, and to sufficiently increase the acceleration of the motor 6. The dead zone escape time may be estimated by an appropriate method. For example, it can be estimated as follows.

The escape time estimation means 19 estimates the dead zone escape time using either or both of the brake command value of the brake force command means 13a in the dead zone and the differential value of the brake command value. Also good.
Since the standby position and distance of the friction pad 5 with respect to the brake rotor 4 are known, and the moving speed of the friction pad 5 relative to the brake command value of the brake force command means 13a, that is, the amount of change in the rotation angle of the motor 6 is also known. If any one of the brake command value and the differential value of the brake command value is known, the dead zone escape time can be estimated. If both the brake command value and its differential value are used, the dead zone escape time can be estimated more accurately.

In this case, the escape time estimation means 19 determines whether or not either one or both of the brake command value of the brake force command means 13a and the differential value of the brake command value in the dead zone is greater than a predetermined threshold value. However, when it is large, the dead zone escape time may be estimated from the differential value.
When the brake command value of the brake force command means 13a or its differential value is small, there is a high possibility of vibration of the brake pedal or sensor noise, for example. Therefore, either one or both of the brake command value and its differential value are compared with the threshold value, and only when the brake command value and the differential value are large, the dead zone escape time is estimated from the differential value, thereby eliminating unnecessary calculations and operations. .

The escape time estimation means 19 stores the dead zone escape time that has actually occurred each time the brake command value is output from zero or less by the brake force command means 13a, and the dead zone escape time greater than or equal to the stored number. May be used to estimate the dead zone escape time during the current operation of the brake force command means.
By storing the actually generated dead zone escape time and using the stored value, the dead zone escape time can be estimated with high accuracy.

In this invention, it has a function of storing the output history of the brake command value of the brake force command means 13a, and stores it within a predetermined time before and after the moment when the target brake force command exceeding zero is generated in the output history. From the output history excluding the output history, the threshold that needs to generate the braking force is set, and only when the brake command value of the braking force command means 13a exceeds the threshold, the preceding drive means 18 in the dead zone Prior operation necessity determination means 20 for performing an operation may be provided.
Thus, by setting a threshold value for determining whether it is necessary to generate the braking force based on the output history, and only when the threshold value is exceeded, if the operation by the preceding drive means 18 in the dead zone is performed, the braking force is not actually generated. It is not necessary to perform the useless driving operation of the motor 6, and power consumption can be reduced.

In the present invention, a vehicle equipped with this electric brake device has acceleration command means 12a for accelerating the vehicle, and the preceding drive means 18 is only when the output of the acceleration command means 12a is not more than a predetermined value. The motor 6 may be driven in a dead zone. The acceleration command means 12a is, for example, an accelerator pedal stroke sensor. The predetermined value is determined as appropriate.
If the motor 6 is driven in the dead zone only when the speed is low to a certain extent and the motor 6 is not driven in the dead zone at a high speed, the adjustment of the electric brake device may occur. Even if a braking force is generated, it is possible to avoid a decrease in traveling safety.

  An electric brake device according to the present invention includes a brake rotor that rotates integrally with a wheel, a friction pad that contacts the brake rotor to generate a braking force, an electric motor, and an output of the motor as a pressing force of the friction pad. Electric transmission having a transmission mechanism for conversion, a brake force command means for detecting a brake command value of the brake operation means and instructing it as a target brake force, and a brake control device for driving the motor in response to the command of the target brake force In the brake device, the friction pad is in contact with the brake rotor during a certain period in the initial stage of the process in which the brake command value of the brake force command means increases from zero to an amount corresponding to the target brake force. A dead zone setting means for setting a dead zone for maintaining the braking force at zero without performing the dead zone, Since the friction pad does not contact the brake rotor, the brake force is zero, and the preceding drive means for driving the motor so that the motor is rotating at an angular velocity equal to or higher than a predetermined value is provided, The influence of the inertia of the motor can be reduced, so that quick braking force can be exerted, the driver's operation feeling can be improved, the motor can be designed with a large torque, the power consumption can be reduced, and the operating noise generated by torque fluctuation can be reduced.

It is a block diagram which shows the conceptual structure of the electric brake device which concerns on one Embodiment of this invention. (A)-(C) is a graph which respectively shows the relationship between time and brake-brake command value when operating the electric brake device, the relationship between time and brake force, and the relationship between time and motor rotation angle. . It is a flowchart which shows an example of control operation of the electric brake device. It is a flowchart which shows the other example of control operation of the electric brake device.

  A first embodiment of the present invention will be described with reference to FIGS. This electric brake device includes a brake main body 1 that is a mechanical component and a brake control device 2 that controls the brake main body 1. The brake body 1 includes a brake rotor 4 such as a brake disk that rotates integrally with the wheel 3, a friction pad 5 that contacts the brake rotor 4 to generate a braking force, an electric motor 6, and an output of the motor 6. And a transmission mechanism 7 that converts the pressure into the pressing force of the friction pad 5. The motor 6 may be a motor with a speed reducer or a motor without a speed reducer. In this example, the motor 6 has a rotation angle estimation means 8 that detects the rotation angle of a motor rotor (not shown). The rotation angle estimation means 8 may be a means for estimating the rotation angle of the motor rotor from the detected value of the rotation axis of the wheel 3 in addition to the means for directly detecting the rotation angle of the motor rotor.

  The control system will be described. The ECU 11, which is the main electric control unit of an automobile equipped with this electric brake device, receives a detection signal from the acceleration command means 12 a that detects the operation amount of the accelerator operation means 12 and a braking force that detects the operation amount of the brake operation means 13. A brake command value which is a detection signal of the command means 13a is input. The accelerator operation means 12 and the brake operation means 13 are each composed of an accelerator pedal and a brake pedal, for example. The acceleration command means 12a and the brake force command means 13a are each composed of a stroke sensor that detects the operation amount of each pedal. The ECU 11 controls a traveling drive source (not shown) such as an engine or a motor in accordance with the operation amount input from the acceleration command means 12a. A target brake force command, which is a brake command value input from the brake force command means 13a to the ECU 11, is distributed from the ECU 11 to the brake control device 2 of the electric brake device for each wheel. In addition to this, the ECU 11 performs integrated control, cooperative control, and the like of the entire automobile.

  The brake control device 2 is an ECU dedicated to the brake, and includes a basic brake control device 15 and power conversion means 16 as its basic configuration. The basic control means 15 generates a motor drive command so that the target brake force that is the input brake brake command value is generated, and outputs the motor drive command to the power conversion means 16. The power conversion means 16 controls the motor current applied to the motor 6 according to the motor drive command. When the motor 6 is an AC motor such as a synchronous motor or an induction motor, the power conversion means 16 includes an inverter <not shown> and controls the motor current by, for example, PWM control. The basic control means 15 performs rotation angle feedback control, phase control for improving the efficiency of the motor 6, and the like using the detected value of the rotation angle by the rotation angle estimation means 8. In the feedback control, proportional integral (PI) control or proportional integral derivative (PID) control is performed.

  In this embodiment, in the electric brake device having such a basic structure, the dead zone setting means 17 and the preceding drive means 18 are provided in the brake control device 2, and the escape time estimating means 19 and the preceding action necessity determining means 20 are further provided. Provided and configured.

  The dead zone setting means 17 maintains the braking force at zero without the friction pad 5 coming into contact with the brake rotor 4 in a certain interval in the initial stage of the process in which the brake command value of the braking force command means 13a increases from zero. It is a means for setting a dead zone. The dead zone is a range corresponding to play generally provided in a brake pedal in the case of a conventional hydraulic brake. The dead zone setting means 17 is provided, for example, in the basic control means 15 or in the preceding stage. The dead zone setting means 17 may be provided in the brake force command means 13a, but even in that case, the brake control device referred to in the claims is a concept including the dead zone setting means 17.

In the dead zone, the preceding drive means 18 is configured so that the friction pad 5 does not contact the brake rotor 4 and the braking force is zero, and the motor is rotating at an angular velocity equal to or greater than a predetermined value. Means for driving the motor. A target brake force applied to the brake control device 2 is input to the preceding drive means 18 via the ECU 11 of the brake force command means 13a, and the basic control means 15 is inactivated while the basic control means 15 does not operate due to the dead zone. Instead, a motor drive command is output to the power conversion means 16.
In this embodiment, the preceding drive means 18 drives the motor 6 in the dead zone only when the output of the acceleration command means 12a is a predetermined value or less.

The escape time estimation means 19 is used until the moment when the brake command value of the brake force command means 13a escapes from the dead zone and the brake force starts to be generated when the brake operation means 13 is operated from zero or less. It is a means for estimating the dead zone escape time which is the time.
The preceding drive means 18 controls the motor 6 so that a braking force starts to be generated when the dead zone escape time estimated by the escape time estimation means has elapsed.

  In this example, the escape time estimation means 19 estimates the dead zone escape time using either or both of the brake command value of the brake force command means 13a in the dead zone and the differential value of the brake command value. To do. In this case, the escape time estimation means 19 determines whether or not either one or both of the brake command value of the brake force command means 13a and the differential value of the brake command value in the dead zone is greater than a predetermined threshold value. If it is larger, the dead zone escape time is estimated from the differential value.

  The preceding operation necessity determination means 20 has a function of storing the output history of the brake command value of the brake force command means 13a, before and after the moment when the target brake force command exceeding zero is generated in the output history. A threshold that needs to generate a braking force is set from the output history excluding the output history stored within a predetermined time, and the preceding in the dead zone is set only when the brake command value of the braking force command means exceeds the threshold. It is means for causing the drive means 18 to perform an operation.

The concept of the operation according to the above configuration will be described with reference to FIG. The figure shows the concept of the operation of the brake force command means 13a to the electric brake device and the accompanying brake force and the operation of the motor 6.
The basic control means 15 that controls according to the brake command value of the brake force command means 13a has a certain dead zone as shown in FIG. This dead zone is a range corresponding to play normally provided on a brake pedal.
The case where the proposed method according to this embodiment is applied to the braking force and the operation of the motor 6 when the brake command value of the brake force command means 13a is issued is indicated by a solid line, and the case where it is not applied is indicated by a dotted line. With this proposed method, no braking force is generated in the dead zone for recognizing the brake command value of the brake force command means 13a, but the motor 6 is accelerated in the direction in which the brake force is generated, and the brake command of the brake force command means 13a is As soon as the value goes out of the dead zone, the braking force 6 is generated.

In this case, the motor 6 is gently accelerated by the proposed method, so that operation noise due to torque fluctuation can be suppressed. That is, in this proposed method, since the motor 6 is rotated in advance, the brake operation means 13 can be stepped on even if the basic control means accelerates slowly by reducing the proportional gain of feedback control 15. The time to reach the maximum braking force from the beginning can be made the same as the conventional method. In addition, since the peak power input to the motor 6 is reduced, the load on the power source can be reduced, for example, by suppressing a voltage drop due to excessive output in a battery (not shown).
-As for the method of accelerating the motor 6 in advance, for example, the amount of change in the dead zone of the brake command value of the brake force command means 13a may be observed, and the time to escape from the dead zone may be estimated from the amount of change. Alternatively, each time the brake force command means 13 is operated, the time until the dead zone is removed may be stored and estimated from the stored information.

  The brake force estimating means 14 is a means for estimating the brake force generated by the electric brake device with respect to the wheel 3 or calculating it. The brake force estimating means 14 is, for example, a strain sensor (not shown) for detecting distortion of a frame (not shown) such as a brake caliper that supports the transmission mechanism 7 and the motor 6 in the brake main body 2, and for supporting the wheel 3. It is comprised by the means etc. which estimate a braking force from the detected value of the load sensor which is installed in the bearing for these wheels, etc., and detects the applied load of each axial direction from distortion of the outer ring | wheel etc. of the bearing.

  Next, the operation of the above configuration and the more specific functions of the respective means 15 to 20 will be described with reference to the flowchart of FIG. FIG. 3 shows an overall operation flow of the brake control device 2. This figure shows an example of estimating the time until the dead zone is removed from the differential value of the operation in the dead zone with respect to the output of the brake force command means 13a.

  The electric brake device 2 acquires the brake command value Ft of the brake force command means 13a (step S1), and in step S2, the basic control means 15 determines whether or not the brake command value Ft is greater than zero. If it is not greater than zero, the basic control means 15 shifts to the non-braking state (step S10) and causes the motor 6 to wait at a predetermined position. This predetermined position is a position where a normal pad clearance occurs.

In step S2, the brake command value Ft is compared with zero in the illustrated example. However, when the basic control means 15 determines that the brake command value Ft is not zero, a disturbance element such as a brake pedal vibration or a sensor is used. In order to remove the influence of noise and the like, a predetermined threshold value that is not zero is provided, and in step S2,
It may be determined that Ft> threshold.
Alternatively, a filter (not shown) for removing the disturbance is provided for the output of the brake command value Ft of the brake force command means 13a, and the output of the brake command value Ft that has passed through this filter is input to the brake control device 2. In step S2, Ft> 0 may be determined.

If it is determined in step S2 that the brake command value Ft is greater than zero, the basic control means 15 shifts to the braking state (step S3), but whether or not the brake command value Ft is less than the dead zone threshold F _blk , That is, it is judged by the dead zone setting means 17 whether it is in the range of a dead zone (step S4).
When the brake command value Ft is less than the dead zone threshold value F _blk , the escape time estimation means 19 calculates the slope dFt / dt of the predetermined time t (step S5). After that, the time to escape the dead zone, that is,
∫dFt (t) / dt · dτ <t _blk
The shortest time t _blk is calculated (step S6). This shortest time t _blk is the dead zone escape estimation time. The predetermined time t is determined as appropriate.

After this, as shown in step S7,
ω (t _blk ) = ω ′
θ (t _blk ) <θ ₀
Here, ω ′: Predetermined value (set arbitrarily)
θ ₀ : Predictive driving means 18 estimates the motor torque that satisfies the condition determined by the rotation angle that becomes the pad contact position.
Incidentally, the rotation angle in the dead zone exit time t _blk to escape the dead zone theta (t _blk), to prevent the problem that the braking force is generated before disengaging the dead band, the comparison formula of the pad contacting position theta ₀ You may compare with below the value which subtracted the predetermined rotation angle from. That is, the above equation is
θ (t _blk ) <θ ₀ − (predetermined rotation angle)
It is also good. The predetermined rotation angle is a suitably designed value.

The preceding drive means 18 drives the motor 6 with the motor torque estimated in this way. That is, the electric brake device is driven (step S8).
If it is determined in step S4 that the brake command value Ft is equal to or greater than the dead zone threshold value F _blk , that is, if it is determined that the dead zone has been removed, the process proceeds to step S9, where the braking force of the brake force command value that is the operation amount of the brake operating means The basic control means 15 drives the motor 6 so that the electric brake device is driven normally (step S8).

FIG. 4 shows an example in which the dead zone escape time estimation method is changed in the embodiment shown in FIGS. This embodiment is the same as the first embodiment shown in FIGS. 1 to 3 except for matters to be specifically described.
In this embodiment, every time the brake operation means 13 (FIG. 1) is operated and the brake force command means 13a outputs a brake command value, the time from the start of operation until the dead zone is removed is stored, and based on the stored information. Estimate the time until the dead zone is removed.

Specifically, if it is determined in step S2 that the brake command value Ft of the brake force command means 13a is not zero and it is determined in step S4 that it is within the dead zone, the escape time estimation means 19 in FIG. Counter (not shown) is added (step S5 '), and in step S6', from the stored counter value,
∫dFt (t) / dt · dτ <t _blk
The shortest time t _blk is obtained, and this value is estimated as the dead zone escape time.

  Thereafter, similarly to the control example of FIG. 3, the calculation of the motor torque that satisfies the conditions (step S7), the drive of the motor 6 (drive of the electric brake device) is performed (step S8), and the processing from the start to step S8 is performed. Repeatedly, during this repetition, the counter is added (step S5 ') and timed. If it is determined in step S4 whether or not the dead zone has been removed, the counter value at that time is stored as the dead zone escape time, and the motor 6 is controlled so that the braking force corresponds to the normal brake command value. Drive (drive the electric brake device). This stored counter value is used for estimation in step S6 '. If it is determined in step S2 that the brake command value Ft is less than or equal to zero, the counter is cleared.

In addition, when estimating the dead zone escape time t _blk in step S6 ′, an average value or deviation of the stored values of the predetermined number of times may be acquired and used for estimation.

According to these embodiments, as described above, a dead zone is provided in the brake control device 2 that drives the motor 6 in accordance with the brake command of the brake force command means 13a, and in this dead zone, based on the operation of the brake force command means 13a. Thus, the motor is accelerated in advance to an angular velocity equal to or greater than a predetermined value in a region where no braking force is generated. Therefore, the following effects can be obtained.
-The influence of the inertia of the motor 6 can be reduced and the braking force can be exerted quickly. Therefore, the feeling of the driver is improved. In addition, since a decrease in response speed due to an increase in inertia of the motor 6 can be compensated, a design using the motor 6 having a large torque becomes possible, and power consumption can be reduced.
・ Sudden output fluctuations of the motor 6 can be suppressed, reducing the maximum load on the power supply.
・ Operation noise caused by torque fluctuation can be reduced.

DESCRIPTION OF SYMBOLS 1 ... Brake body 2 ... Brake control device 3 ... Wheel 4 ... Brake rotor 5 ... Friction pad 5
6 ... motor 7 ... transmission mechanism 8 ... rotation angle estimation means 11 ... ECU
12a ... acceleration command means 13 ... brake operation means 13a ... brake force command means 14 ... brake force estimation means 15 ... basic control means 17 ... dead zone setting means 18 ... preceding drive means 19 ... escape time estimation means 20 ... priority action necessity judgment means

Claims (8)

A brake rotor that rotates integrally with the wheel, a friction pad that contacts the brake rotor to generate a braking force, an electric motor, a transmission mechanism that converts the output of the motor into a pressing force of the friction pad, and a brake operation In an electric brake device having a brake force command means for detecting an operation amount of the means and instructing it as a target brake force, and a brake control device for driving the motor in response to the command of the target brake force,
In the brake control device,
A dead zone setting means for setting a dead zone in which the friction pad does not come into contact with the brake rotor and maintains the brake force at zero during a certain period in an initial stage in which the brake command value of the brake force command means rises from zero; ,
Preceding drive means for driving the motor so that the friction pad does not contact the brake rotor, the braking force is zero, and the motor is rotating at an angular velocity equal to or greater than a predetermined value in the dead zone; the setting,
The predetermined section is a range corresponding to play generally provided in a brake pedal,
An electric brake device characterized by that. A brake rotor that rotates integrally with the wheel, a friction pad that contacts the brake rotor to generate a braking force, an electric motor, a transmission mechanism that converts the output of the motor into a pressing force of the friction pad, and a brake operation In an electric brake device having a brake force command means for detecting an operation amount of the means and instructing it as a target brake force, and a brake control device for driving the motor in response to the command of the target brake force,
In the brake control device,
A dead zone setting means for setting a dead zone in which the friction pad does not come into contact with the brake rotor and maintains the brake force at zero during a certain period in an initial stage in which the brake command value of the brake force command means rises from zero; ,
Preceding drive means for driving the motor so that the friction pad does not contact the brake rotor, the braking force is zero, and the motor is rotating at an angular velocity equal to or greater than a predetermined value in the dead zone; Provided,
A function of storing an output history of a brake command value of the brake force command means, and an output history stored within a predetermined time before and after the moment when a target brake force command exceeding zero is generated in the output history. A pre-operation that sets a threshold that needs to generate a braking force from the output history excluding, and performs an operation by the pre-driving unit in the dead zone only when a brake command value of the braking force command unit exceeds the threshold. Electric brake device provided with necessity judgment means. A brake rotor that rotates integrally with the wheel, a friction pad that contacts the brake rotor to generate a braking force, an electric motor, a transmission mechanism that converts the output of the motor into a pressing force of the friction pad, and a brake operation In an electric brake device having a brake force command means for detecting an operation amount of the means and instructing it as a target brake force, and a brake control device for driving the motor in response to the command of the target brake force,
In the brake control device,
A dead zone setting means for setting a dead zone in which the friction pad does not come into contact with the brake rotor and maintains the brake force at zero during a certain period in an initial stage in which the brake command value of the brake force command means rises from zero; ,
Preceding drive means for driving the motor so that the friction pad does not contact the brake rotor, the braking force is zero, and the motor is rotating at an angular velocity equal to or greater than a predetermined value in the dead zone; Provided,
Having an acceleration command means for vehicle mounting the electric braking apparatus to accelerate the vehicle, the preceding driving means, the output of said acceleration command means when more than a predetermined value only, driving the motor in the dead zone Electric brake device. A brake rotor that rotates integrally with the wheel, a friction pad that contacts the brake rotor to generate a braking force, an electric motor, a transmission mechanism that converts the output of the motor into a pressing force of the friction pad, and a brake operation In an electric brake device having a brake force command means for detecting an operation amount of the means and instructing it as a target brake force, and a brake control device for driving the motor in response to the command of the target brake force,
In the brake control device,
A dead zone setting means for setting a dead zone in which the friction pad does not come into contact with the brake rotor and maintains the brake force at zero during a certain period in an initial stage in which the brake command value of the brake force command means rises from zero; ,
Preceding drive means for driving the motor so that the friction pad does not contact the brake rotor, the braking force is zero, and the motor is rotating at an angular velocity equal to or greater than a predetermined value in the dead zone; Provided,
Estimating dead zone escape time, which is the time until the moment when the brake command value of the brake force command means starts to generate the brake force when the brake operation means is operated from zero or less, or until the brake force starts to be generated The brake control device includes an escape time estimating means for controlling the motor so that a brake force starts to be generated when the dead zone escape time estimated by the escape time estimating means elapses. . 5. The electric brake device according to claim 4 , wherein the escape time estimation means uses one or both of a brake command value of the brake force command means in the dead zone and a differential value of the brake command value. The electric brake device for estimating the dead zone escape time. 6. The electric brake device according to claim 4 or 5 , wherein the escape time estimating means has a predetermined one or both of a brake command value of the brake force command means and a differential value of the brake command value in the dead zone. An electric brake device that determines whether or not the dead zone escape time is estimated from the differential value. 5. The electric brake device according to claim 4 , wherein the escape time estimating means stores the dead zone escape time actually generated each time the brake command value is output from zero or less by the brake force command means. An electric brake device that estimates the dead zone escape time when the brake force command means is currently operated, using a predetermined number or more of the stored values of the dead zone escape time.   The electric brake device according to any one of claims 1 to 7, wherein the brake force command means is provided on a pedal that is the brake operation means provided in a vehicle on which the electric brake device is mounted. Electric brake device that is a stroke sensor.

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