# US 11,897,442 B2 · Brake controller and method for controlling brake

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- Number: US 11,897,442 B2
- Document ID: US11897442B2
- Status: Granted
- Kind: B2
- Application number: 17/319,642
- Filed: 2021-05-13
- Published: 2021-12-02
- Granted: 2024-02-13
- Earliest claimed: 2020-06-01
- Assignees: Toyota Jidosha Kabushiki Kaisha
- Applicants: Toyota Jidosha Kabushiki Kaisha
- Inventors: Hirofumi Momose
- Web page: https://patentgrep.com/patent/US11897442B2

## CPC

- B60T 8/173: Eliminating or reducing the effect of unwanted signals, e.g. due to vibrations or electrical noise
- B60T 13/662: {characterised by specified functions of the control system components}
- B60T 7/22: initiated by contact of vehicle, e.g. bumper, with an external object, e.g. another vehicle {, or by means of contactless obstacle detectors mounted on the vehicle}
- B60T 8/172: Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters {(B60T8/17551 takes precedence)}
- B60T 13/741: {acting on an ultimate actuator}
- B60T 2201/10: Automatic or semi-automatic parking aid systems
- B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES

## Abstract

A brake controller includes a control circuit that calculates target braking force every predetermined period, in accordance with feedback control on at least acceleration or speed of a vehicle steered for parking; and a filter circuit that outputs, to a brake device, output braking force obtained by applying a low-pass filter having a predetermined time constant to the target braking force when the amount of change in the target braking force over time is within a predetermined tolerable range. When the amount of change is outside the tolerable range, the filter circuit outputs, to the brake device, the target braking force as output braking force or outputs thereto output braking force calculated by correcting smoothed target braking force, which is obtained by applying the low-pass filter to the target braking force, so that a difference between the smoothed target braking force and the target braking force is within the tolerable range.

## Claims

### Claim 1

A brake controller for controlling a brake device of a vehicle, the brake controller comprising:
a control circuit that calculates target braking force every predetermined period, in accordance with feedback control on at least acceleration or speed of the vehicle steered for parking; and
a filter circuit that outputs, when the amount of change in the target braking force over time is within a predetermined tolerable range, output braking force to the brake device, the output braking force being obtained by applying a low-pass filter having a predetermined time constant to the target braking force,
on the other hand, when the amount of change is outside the predetermined tolerable range, outputs, without applying the low-pass filter to the target braking force, the target braking force to the brake device as the output braking force or outputs, to the brake device, the output braking force calculated by correcting smoothed target braking force so that a difference between the smoothed target braking force and the target braking force is within the predetermined tolerable range, the smoothed target braking force being obtained by applying the low-pass filter to the target braking force.

### Claim 2 (depends on 1)

The brake controller according to claim 1, wherein the filter circuit comprises
a tolerable-range setting circuit that sets, every time the target braking force is inputted, an upper limit and a lower limit of the tolerable range so as to include the inputted target braking force therein;
a smoothing circuit that applies the low-pass filter to the inputted target braking force to output the smoothed target braking force; and
a clipping circuit that outputs, to the brake device as the output braking force, the smoothed target braking force when the smoothed target braking force is within the tolerable range, the upper limit when the smoothed target braking force is greater than the upper limit, and the lower limit when the smoothed target braking force is less than the lower limit.

### Claim 3 (depends on 2)

The brake controller according to claim 2, wherein the greater the inputted target braking force, the more the tolerable-range setting circuit widens the tolerable range.

### Claim 4 (depends on 1)

The brake controller according to claim 1, wherein the filter circuit comprises
a smoothing circuit that applies the low-pass filter to the target braking force inputted into the filter circuit to output the smoothed target braking force;
a switch for outputting the smoothed target braking force or the target braking force to the brake device as the output braking force; and
a determining circuit that calculates, as the amount of change, a difference between the inputted target braking force and target braking force inputted immediately previous thereto and causes the switch to output, to the brake device as the output braking force, the smoothed target braking force when the amount of change is within the predetermined tolerable range and the target braking force when the amount of change is outside the predetermined tolerable range.

### Claim 5

A method for controlling a brake device of a vehicle, comprising:
calculating target braking force every predetermined period, in accordance with feedback control on at least acceleration or speed of the vehicle steered for parking;
outputting, when the amount of change in the target braking force over time is within a predetermined tolerable range, output braking force to the brake device, the output braking force being obtained by applying a low-pass filter having a predetermined time constant to the target braking force; and
outputting, when the amount of change is outside the predetermined tolerable range, without applying the low-pass filter to the target braking force, the target braking force to the brake device as the output braking force or outputting, to the brake device, the output braking force calculated by correcting smoothed target braking force so that a difference between the smoothed target braking force and the target braking force is within the predetermined tolerable range, the smoothed target braking force being obtained by applying the low-pass filter to the target braking force.