# US 2014/0207355 A1 · Braking force control apparatus for vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0207355 A1 - Document ID: US20140207355A1 - Status: Published application - Kind: A1 - Application number: 14/241,937 - Filed: 2011-08-29 - Published: 2014-07-24 - Earliest claimed: 2011-08-29 - Assignees: Toyota Jidosha Kabushiki Kaisha - Inventors: Daisuke Akaho; Masatoshi Nakatsu - Web page: https://patentgrep.com/patent/US20140207355A1 ## 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) - B60L 3/108: {whilst braking, i.e. ABS} - B60L 7/18: Controlling the braking effect (B60L7/12, B60L7/14, B60L7/16 take precedence) - B60L 7/26: Controlling the braking effect - B60L 15/2009: {for braking} - B60T 1/10: by utilising wheel movement for accumulating energy, e.g. driving air compressors - B60T 8/17: Using electrical or electronic regulation means to control braking {(detecting or indicating faulty operation B60T8/885)} - B60T 8/176: Brake regulation specially adapted to prevent excessive wheel slip during vehicle deceleration, e.g. ABS (B60T8/1755 takes precedence) - B60T 8/17616: {Microprocessor-based systems} - B60T 11/04: transmitting mechanically - B60T 13/586: {the retarders being of the electric type} - B60W 10/08: including control of electric propulsion units, e.g. motors or generators - B60W 10/184: with wheel brakes - B60W 30/02: Control of vehicle driving stability - B60W 30/18127: {Regenerative braking} - B60L 2220/44: Wheel Hub motors, i.e. integrated in the wheel hub - B60L 2260/26: Transition between different drive modes - B60T 2270/604: Merging friction therewith; Adjusting their repartition - B60W 2520/26: Wheel slip - Y02T 10/64: Electric machine technologies in electromobility - Y02T 10/72: Electric energy management in electromobility - 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 - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - 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 - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An electronic control unit of a braking force control apparatus for a vehicle activates, as a first state, in-wheel motors in a regeneration state, thereby generating motor braking torques, and causes friction brake mechanisms to generate friction braking forces. Moreover, the unit activates, as a second state, the motors in a power running state, thereby generating motor driving torques, and causes the mechanisms to generate friction braking forces. Then, when the state is caused to transition between the first state and the second state, the unit changes magnitudes of the braking torques or the driving torques generated by the motors to one of increase and decrease, and changes magnitudes of the friction braking forces generated by the mechanisms to one of increase and decrease. ## Claims ### Claim 1 A braking force control apparatus for a vehicle, comprising: an electromotive force generation mechanism for generating, independently on a wheel of a vehicle, an electromagnetic driving force or an electromagnetic braking force; a braking force generation mechanism for generating a mechanical braking force on the wheel rotated by at least the electromagnetic driving force generated by the electromotive force generation mechanism; and braking control means for controlling activations of the electromotive force generation mechanism and the braking force generation mechanism so as to generate a braking force on the wheel, and for activating, when the wheel tends to be locked, the electromotive force generation mechanism in any one of a power running state and a regeneration state so as to generate the electromagnetic driving force or the electromagnetic braking force, and, simultaneously, controlling the braking force generation mechanism to generate the mechanical braking force, wherein: the braking control means controls generation of the braking force on the wheel in: a first state where the electromotive force generation mechanism is activated in the regeneration state so as to generate the electromagnetic braking force having a predetermined magnitude, and, simultaneously, the braking force generation mechanism is controlled to generate the mechanical braking force having a predetermined magnitude, thereby activating the electromotive force generation mechanism and the braking force generation mechanism in cooperation with each other; and a second state where the electromotive force generation mechanism is activated in the power running state so as to generate the electromagnetic driving force having a predetermined magnitude, and, simultaneously, the braking force generation mechanism is controlled to generate the mechanical braking force having a predetermined magnitude, thereby activating the electromotive force generation mechanism and the braking force generation mechanism in cooperation with each other; and when a state is caused to transition from one of the first state and the second state to another of the first state and the second state, a magnitude of the electromagnetic braking force or a magnitude of the electromagnetic driving force generated by the electromotive force generation mechanism is changed to one of increase and decrease, and a magnitude of the mechanical braking force generated by the braking force generation mechanism is changed to one of increase and decrease. ### Claim 2 (depends on 1) A braking force control apparatus for a vehicle according to claim 1, wherein the braking control means is configured to: determine a required braking force required for the wheel for braking the vehicle; and change, in a case where the state is caused to transition, when a magnitude of the determined required braking force increases or decreases, any one of the magnitude of the electromagnetic driving force generated by the electromotive force generation mechanism, the magnitude of the electromagnetic braking force generated by the electromotive force generation mechanism, and the magnitude of the mechanical braking force generated by the braking force generation mechanism to one of increase and decrease. ### Claim 3 (depends on 2) A braking force control apparatus for a vehicle according to claim 2, wherein the braking control means is configured to: in a case where the state is caused to transition from the first state to the second state, when the magnitude of the required braking force increases, increase the magnitude of the mechanical braking force generated by the braking force generation mechanism while maintaining the magnitude of the electromagnetic braking force generated by the electromotive force generation mechanism, and when the magnitude of the required braking force decreases, decrease the magnitude of the electromagnetic braking force generated by the electromotive force generation mechanism while maintaining the magnitude of the mechanical braking force generated by the braking force generation mechanism; and in a case where the state is caused to transition from the second state to the first state, when the magnitude of the required braking force increases, decrease the magnitude of the electromagnetic driving force generated by the electromotive force generation mechanism while maintaining the magnitude of the mechanical braking force generated by the braking force generation mechanism, and when the magnitude of the required braking force decreases, decrease the magnitude of the mechanical braking force generated by the braking force generation mechanism while maintaining the magnitude of the electromagnetic braking force generated by the electromotive force generation mechanism. ### Claim 4 (depends on 2) A braking force control apparatus for a vehicle according to claim 2, wherein the braking control means is configured to: compare a change amount in the magnitude of the determined required braking force and a predetermined change amount set in advance with each other; change, when the change amount is more than the predetermined change amount set in advance, the magnitude of the mechanical braking force generated by the braking force generation mechanism to one of increase and decrease depending on a magnitude of the change amount; and change, when the change amount is equal to or less than the predetermined change amount set in advance, the magnitude of the electromagnetic braking force generated by the electromotive force generation mechanism to one of increase and decrease depending on the magnitude of the change amount. ### Claim 5 (depends on 1) A braking force control apparatus for a vehicle according to claim 1, wherein the braking control means uses, when the state is caused to transition, any one of the electromagnetic driving force generated by the electromotive force generation mechanism, the electromagnetic braking force generated by the electromotive force generation mechanism, and the mechanical braking force generated by the braking force generation mechanism to avoid a tendency of lock of the wheel. ### Claim 6 (depends on 5) A braking force control apparatus for a vehicle according to claim 5, wherein the braking control means is configured to, in the case where the state is caused to transition: use, when a magnitude of a friction coefficient of a road surface on which the vehicle travels is smaller than a magnitude of a predetermined friction coefficient, the electromagnetic driving force or the electromagnetic braking force generated by the electromotive force generation mechanism so as to avoid the tendency of the lock of the wheel; and use, when the magnitude of the friction coefficient of the road surface on which the vehicle travels is equal to or more than the magnitude of the predetermined friction coefficient, the mechanical braking force generated by the braking force generation mechanism so as to avoid the tendency of the lock of the wheel. ### Claim 7 (depends on 5) A braking force control apparatus for a vehicle according to claim 5, wherein the braking control means is configured to: use, when the state is caused to transition from the first state to the second state, the electromagnetic driving force or the electromagnetic braking force generated by the electromotive force generation mechanism so as to avoid the tendency of the lock of the wheel; and use, when the state is caused to transition from the second state to the first state, the mechanical braking force generated by the braking force generation mechanism so as to avoid the tendency of the lock of the wheel. ### Claim 8 (depends on 1) A braking force control apparatus for a vehicle according to claim 1, wherein the braking control means causes, when the electromotive force generation mechanism transitions from a state where one of the electromagnetic driving force and the electromagnetic braking force is generated to a state where another of the electromagnetic driving force and the electromagnetic braking force is generated, the state to transition from the one of the first state and the second state to the another of the first state and the second state. ### Claim 9 (depends on 1) A braking force control apparatus for a vehicle according to claim 1, wherein the braking control means causes, when a driver carries out an operation of changing a travel state of the vehicle, the state to transition from the one of the first state and the second state to the another of the first state and the second state. ### Claim 10 (depends on 9) A braking force control apparatus for a vehicle according to claim 9, wherein the operation carried out by the driver to change the travel state of the vehicle comprises at least one of a brake operation for braking the vehicle, an accelerator operation for accelerating the vehicle, or a steering operation for turning the vehicle. ### Claim 11 (depends on 10) A braking force control apparatus for a vehicle according to claim 10, wherein the braking control means is configured to: control, when the driver carries out the brake operation, the electromotive force generation mechanism to generate the electromagnetic braking force or control the braking force generation mechanism to generate the mechanical braking force earlier in time; control, when the driver carries out the accelerator operation, the electromotive force generation mechanism to generate the electromagnetic driving force earlier in time; and control, when the driver carries out the steering operation, the electromotive force generation mechanism to generate the electromagnetic braking force or control the braking force generation mechanism to generate the mechanical braking force on a wheel on an inside of turn of the vehicle earlier in time, and control the electromotive force generation mechanism to generate the electromagnetic driving force on a wheel on an outside of the turn of the vehicle earlier in time. ### Claim 12 (depends on 1) A braking force control apparatus for a vehicle according to claim 1, wherein the braking control means causes, based on a state of a road surface on which the vehicle travels, the state to transition from the one of the first state and the second state to the another of the first state and the second state. ### Claim 13 (depends on 12) A braking force control apparatus for a vehicle according to claim 12, wherein the braking control means is configured to: estimate a slip ratio generated on the wheel, thereby estimating, based on the estimated slip ratio, a magnitude of a friction coefficient of the road surface on which the vehicle travels; determine, when the magnitude of the estimated friction coefficient of the road surface is less than a magnitude of a predetermined friction coefficient, to cause the state to transition from the first state to the second state; and determine, when the magnitude of the estimated friction coefficient of the road surface is equal to or more than the magnitude of the predetermined friction coefficient, to cause the state to transition from the second state to the first state.