# US 12,005,880 B2 · Vehicle brake system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,005,880 B2 - Document ID: US12005880B2 - Status: Granted - Kind: B2 - Application number: 17/573,231 - Filed: 2022-01-11 - Published: 2022-07-21 - Granted: 2024-06-11 - Earliest claimed: 2021-01-15 - Assignees: Toyota Jidosha Kabushiki Kaisha; Advics Co., Ltd. - Applicants: Toyota Jidosha Kabushiki Kaisha; Advics Co., Ltd. - Inventors: Misuzu Shimazaki; Yusuke Kamiya; Ken Kuzuya - Web page: https://patentgrep.com/patent/US12005880B2 ## CPC - B60T 8/94: on a fluid pressure regulator - B60T 7/042: {by electrical means, e.g. using travel or force sensors} - B60T 8/4081: {Systems with stroke simulating devices for driver input (B60T8/4077 takes precedence)} - B60T 13/662: {characterised by specified functions of the control system components} - B60T 17/22: Devices for monitoring or checking brake systems; Signal devices - B60T 2201/03: Brake assistants - B60T 2270/402: Back-up - B60T 2270/406: Test-mode; Self-diagnosis - B60T 2270/88: Pressure measurement in brake systems - F16D 2066/001: {Temperature} - 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 - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES ## Abstract A vehicle brake system, including: a first hydraulic-pressure control mechanism and a second hydraulic-pressure control mechanism configured to control a braking force; and a controller including a first-abnormal-state detecting device configured to detect whether the first hydraulic-pressure control mechanism is in a first abnormal state, a second-abnormal-state detecting device configured to detect whether the first hydraulic-pressure control mechanism is in a second abnormal state that the first hydraulic-pressure control mechanism reaches before reaching the first abnormal state, and an assist control device configured to control the second braking-force control mechanism so as to control the braking force when an assist wait time elapses after the second-abnormal-state detecting device has detected that the first hydraulic-pressure control mechanism is in the second abnormal state, the assist wait time being determined based on a temperature of a working fluid obtained by a temperature obtaining device of the brake system. ## Claims ### Claim 1 A brake system for a vehicle, comprising: a first hydraulic-pressure control mechanism configured to control a hydraulic pressure in a plurality of hydraulic brakes respectively provided for a plurality of wheels of the vehicle to thereby control a braking force to be applied to the vehicle; a second braking-force control mechanism configured to control the braking force, the second braking-force control mechanism being different from the first hydraulic-pressure control mechanism; and a controller including a first-abnormal-state detecting device configured to detect whether the first hydraulic-pressure control mechanism is in a first abnormal state as an abnormal state, wherein the controller is configured to: control the first hydraulic-pressure control mechanism so as to control the braking force when the first-abnormal-state detecting device does not detect that the first hydraulic-pressure control mechanism is in the first abnormal state; and control not the first hydraulic-pressure control mechanism but the second braking-force control mechanism so as to control the braking force when the first-abnormal-state detecting device detects that the first hydraulic-pressure control mechanism is in the first abnormal state, wherein the brake system comprises a temperature obtaining device configured to obtain a temperature of a working fluid in the brake system, wherein the controller includes: a second-abnormal-state detecting device configured to detect whether the first hydraulic-pressure control mechanism is in a second abnormal state, the second abnormal state being a state that the first hydraulic-pressure control mechanism reaches before reaching the first abnormal state; and an assist control device configured to control the second braking-force control mechanism so as to control the braking force when an assist wait time elapses after the second-abnormal-state detecting device has detected that the first hydraulic-pressure control mechanism is in the second abnormal state, the assist wait time being determined based on the temperature of the working fluid obtained by the temperature obtaining device. ### Claim 2 (depends on 1) The brake system according to claim 1, comprising a first-actual-hydraulic-pressure obtaining device configured to obtain a first actual hydraulic pressure at intervals of a predetermined cycle time, the first actual hydraulic pressure being an actual hydraulic pressure in the plurality of hydraulic brakes generated by an operation of the first hydraulic-pressure control mechanism, wherein, when the temperature of the working fluid obtained by the temperature obtaining device is not lower than a first set temperature, the first-abnormal-state detecting device monitors, for a first set time, the first actual hydraulic pressure obtained by the first-actual-hydraulic-pressure obtaining device, wherein the first-abnormal-state detecting device detects that the first hydraulic-pressure control mechanism is in the first abnormal state when a difference between the first actual hydraulic pressure and a first target hydraulic pressure is greater than an abnormality determination threshold, wherein, when the temperature of the working fluid is lower than the first set temperature, the first-abnormal-state detecting device monitors, for a second set time that is longer than the first set time, the first actual hydraulic pressure obtained by the first-actual-hydraulic-pressure obtaining device, wherein the first-abnormal-state detecting device detects that the first hydraulic-pressure control mechanism is in the first abnormal state when the difference is greater than the abnormality determination threshold, wherein the second-abnormal-state detecting device monitors, for a third set time that is shorter than the first set time, the first actual hydraulic pressure obtained by the first-actual-hydraulic-pressure obtaining device, and wherein the second-abnormal-state detecting device detects that the first hydraulic-pressure control mechanism is in the second abnormal state when the difference is greater than the abnormality determination threshold. ### Claim 3 (depends on 1) The brake system according to claim 1, wherein the controller includes an assist-wait-time determining device configured to determine the assist wait time such that the assist wait time is longer when the temperature of the working fluid obtained by the temperature obtaining device is lower than a second set temperature than when the temperature of the working fluid is not lower than the second set temperature. ### Claim 4 (depends on 1) The brake system according to claim 1, wherein the controller is configured to determine an operation timing of at least one of the first hydraulic-pressure control mechanism and the second braking-force control mechanism such that the operation timing is earlier when the temperature of the working fluid obtained by the temperature obtaining device is low than when the temperature of the working fluid is high. ### Claim 5 (depends on 1) The brake system according to claim 1, wherein the controller includes an abnormal-state control device configured to control the second braking-force control mechanism so as to control the braking force to be not less than a predetermined abnormal-state target braking force when the first-abnormal-state detecting device detects that the first hydraulic-pressure control mechanism is in the first abnormal state. ### Claim 6 (depends on 1) The brake system according to claim 1, wherein the controller includes: a control-command-value generating device configured to generate a control command value based on a running state of the vehicle; and a brake control device configured to control at least one of the first hydraulic-pressure control mechanism and the second braking-force control mechanism based on the control command value generated by the control-command-value generating device, so as to control the braking force, wherein the control-command-value generating device is configured to generate a target deceleration as the control command value, wherein the brake control device controls the first hydraulic-pressure control mechanism based on the target deceleration when the first-abnormal-state detecting device does not detect that the first hydraulic-pressure control mechanism is in the first abnormal state, and wherein the brake control device stops the first hydraulic-pressure control mechanism from operating and controls the second braking-force control mechanism based on an abnormal-state target deceleration that is greater than the target deceleration when the first-abnormal-state detecting device detects that the first hydraulic-pressure control mechanism is in the first abnormal state.