# US 12,109,996 B2 · Brake control device for vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,109,996 B2 - Document ID: US12109996B2 - Status: Granted - Kind: B2 - Application number: 18/341,847 - Filed: 2023-06-27 - Published: 2023-10-19 - Granted: 2024-10-08 - Earliest claimed: 2018-03-30 - Assignees: Advics Co., Ltd. - Applicants: Advics Co., Ltd. - Inventors: Yusaku Yamamoto - Web page: https://patentgrep.com/patent/US12109996B2 ## CPC - B60T 8/1755: Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve (road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02) - B60T 8/1766: Proportioning of brake forces according to vehicle axle loads, e.g. front to rear of vehicle - B60T 7/12: for automatic initiation; for initiation not subject to will of driver or passenger {(limiting speed of vehicles other than rail vehicles B60K31/00)} - B60W 10/18: including control of braking systems - B60W 40/11: Pitch movement - B60T 8/26: characterised by producing differential braking between front and rear wheels {(using electrical circuitry or regulation means B60T8/17)} - B60T 2230/04: Jerk, soft-stop; Anti-jerk, reduction of pitch or nose-dive when braking - B60T 2260/06: Active Suspension System - B60T 2270/608: Electronic brake distribution (EBV/EBD) features related thereto - 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 - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT ## Abstract A brake control device is applied to a brake device that controls a front-wheel braking force and a rear-wheel braking force. The brake control device includes a ratio calculation circuit that calculates a target front and rear braking force distribution ratio based on a target pitch angle, and a brake control circuit that performs a stability control by operating the brake device based on the target front and rear braking force distribution ratio during braking. ## Claims ### Claim 1 A brake control device for a vehicle applied to a brake device configured to adjust a front-wheel braking force that is a braking force applied to a front wheel of the vehicle and a rear-wheel braking force that is a braking force applied to a rear wheel of the vehicle, the brake control device for the vehicle comprising: a ratio calculation circuit that calculates a target front and rear braking force distribution ratio that is a target value of a front and rear braking force distribution ratio based on a target pitch angle, the front and rear braking force distribution ratio is a ratio of the rear-wheel braking force with respect to the front-wheel braking force, and the target pitch angle is a target value of a pitch angle of the vehicle during braking; and, a brake control circuit that performs a stability control by operating the brake device based on front and rear braking force distribution ratio during braking, wherein in the stability control, the brake control circuit operates the brake device to hold the front and rear braking force distribution ratio at the target front and rear braking force distribution ratio even when a vehicle body deceleration of the vehicle changes, the brake control circuit performs a stable control that lowers the front and rear braking force distribution ratio less than the target front and rear braking force distribution ratio by operating the brake device if the vehicle body deceleration of the vehicle is larger than a switching deceleration during braking, and an ideal front and rear braking force distribution ratio that is the front and rear braking force distribution ratio at which the front wheel and the rear wheel are simultaneously locked, in a graph in which one of a vertical axis and a horizontal axis indicates the front-wheel braking force and the other indicates the rear-wheel braking force, the switching deceleration is set to a value corresponding to a vehicle body deceleration of the vehicle when a line representing a relationship between the target front and rear braking force distribution ratio and the vehicle body deceleration of the vehicle, and a line representing a relationship between the ideal front and rear braking force distribution ratio and the vehicle body deceleration of the vehicle intersect. ### Claim 2 (depends on 1) The brake control device for the vehicle according to claim 1, wherein an anti-dive force that displaces a front portion of the vehicle upward and an anti-lift force that displaces a rear portion of the vehicle downward are generated in the vehicle during braking, the anti-dive force is a force whose absolute value increases as the front-wheel braking force increases, and the anti-lift force is a force that increases as the rear-wheel braking force increases, and the ratio calculation circuit calculates the target front and rear braking force distribution ratio so that a pitch angle of the vehicle estimated from the anti-dive force and the anti-lift force generated in the vehicle during braking becomes the target pitch angle. ### Claim 3 (depends on 1) The brake control device for the vehicle according to claim 1, further comprising: a learning circuit that learns an ideal distribution characteristic that represents the relationship between the ideal front and rear braking force distribution ratio and the vehicle body deceleration of the vehicle during braking; wherein the learning circuit learns the ideal distribution characteristic based on a lock tendency of the rear wheels and a lock tendency of the front wheels during vehicle braking. ### Claim 4 (depends on 1) The brake control device for the vehicle according to claim 1, further comprising: a learning circuit that learns an ideal distribution characteristic that represents the relationship between the ideal front and rear braking force distribution ratio and the vehicle body deceleration of the vehicle during traveling; wherein the learning circuit learns the ideal distribution characteristic based on a vehicle weight obtained based on a motion state of the vehicle during traveling. ### Claim 5 (depends on 1) The brake control device for the vehicle according to claim 1, further comprising, a slip value that is a value representing a degree of slip of the wheel, a ratio modification circuit that modifies the target front and rear braking force distribution ratio so that distribution of the braking force to the rear wheel decreases when the slip value of the front wheel is less than a determination slip value and the slip value of the rear wheel is larger than the determination slip value under a situation where the stability control is performed by the brake control circuit. ### Claim 6 (depends on 1) The brake control device for the vehicle according to claim 1, further comprising a target pitch angle setting circuit that sets the target pitch angle to forward during automatic braking less than the target pitch angle to forward during manual braking. ### Claim 7 (depends on 2) The brake control device for the vehicle according to claim 2, wherein the brake control circuit performs a stable control that lowers the front and rear braking force distribution ratio less than the target front and rear braking force distribution ratio by operating the brake device if the vehicle body deceleration of the vehicle is larger than a switching deceleration during braking, and an ideal front and rear braking force distribution ratio that is the front and rear braking force distribution ratio at which the front wheel and the rear wheel are simultaneously locked, in a graph in which one of a vertical axis and a horizontal axis indicates the front-wheel braking force and the other indicates the rear-wheel braking force, the switching deceleration is set to a value corresponding to a vehicle body deceleration of the vehicle when a line representing a relationship between the target front and rear braking force distribution ratio and the vehicle body deceleration of the vehicle, and a line representing a relationship between the ideal front and rear braking force distribution ratio and the vehicle body deceleration of the vehicle intersect. ### Claim 8 (depends on 7) The brake control device for the vehicle according to claim 7, further comprising: a learning circuit that learns an ideal distribution characteristic that represents the relationship between the ideal front and rear braking force distribution ratio and the vehicle body deceleration of the vehicle during braking; wherein the learning circuit learns the ideal distribution characteristic based on a lock tendency of the rear wheels and a lock tendency of the front wheels during vehicle braking. ### Claim 9 (depends on 7) The brake control device for the vehicle according to claim 7, further comprising: a learning circuit that learns an ideal distribution characteristic that represents the relationship between the ideal front and rear braking force distribution ratio and the vehicle body deceleration of the vehicle during traveling; wherein the learning circuit learns the ideal distribution characteristic based on a vehicle weight obtained based on a motion state of the vehicle during traveling.