# US 11,110,802 B2 · Method for operating a regenerative braking system of a vehicle and control unit for a regenerative braking system of a vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,110,802 B2 - Document ID: US11110802B2 - Status: Granted - Kind: B2 - Application number: 15/557,870 - Filed: 2016-01-22 - Published: 2018-03-22 - Granted: 2021-09-07 - Earliest claimed: 2015-03-18 - Assignees: Robert Bosch GmbH - Applicants: Robert Bosch GmbH - Inventors: Bertram Foitzik; Matthias Kistner; Otmar Bussmann; Rolf Ellwein; Urs Bauer; Robert Kaster - Web page: https://patentgrep.com/patent/US11110802B2 ## CPC - B60L 7/26: Controlling the braking effect - B60L 7/18: Controlling the braking effect (B60L7/12, B60L7/14, B60L7/16 take precedence) - B60T 8/4081: {Systems with stroke simulating devices for driver input (B60T8/4077 takes precedence)} - B60T 13/741: {acting on an ultimate actuator} - B60T 8/4072: {Systems in which a driver input signal is used as a control signal for the additional fluid circuit which is normally used for braking} - B60T 8/4872: {pump-back systems} - B60T 2210/12: Friction - B60T 2270/604: Merging friction therewith; Adjusting their repartition - 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 - 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 method for operating a regenerative braking system of a vehicle by activating at least one motor employable in generator mode taking into consideration a first information with regard to a requested setpoint total braking torque and a second information with regard to an available generator braking torque which is maximally executable by the at least one motor employable in generator mode, if the setpoint total braking torque exceeds a threshold value and/or a piece of warning information regarding a transition to a backup level that is potentially imminent or has occurred of the regenerative braking system, even if the setpoint total braking torque is less than or equal to the maximally executable available generator braking torque, sufficient brake fluid is transferred via at least one hydraulic actuator to a wheel brake cylinder of the regenerative braking system that an air gap of the particular wheel brake cylinder is closed. ## Claims ### Claim 1 A method for operating a regenerative braking system of a vehicle, comprising: activating at least one motor, having a generator mode, of the regenerative braking system taking into consideration a first information with regard to a setpoint total braking torque requested by a driver or an automatic speed control of the vehicle, and a second information with regard to an available generator braking torque which is maximally executable without overcharging a battery of the vehicle using the at least one motor employable in generator mode in such a way that if the setpoint total braking torque is executable at least partially by the maximally executable available generator braking torque, a generator braking torque which is less than or equal to the setpoint total braking torque and less than or equal to maximally executable available generator braking torque is applied to at least one of at least one wheel and at least one axle of the vehicle, with the aid of the at least one motor employable in the generator mode; wherein the application of the generator torque is performed such that, when the setpoint total braking torque is less than or equal to the maximally executable available generator braking torque: prior to at least one of (a) the setpoint total braking torque exceeding a fixedly predefined or establishable threshold value and (b) presence of warning information regarding a transition to a backup level of the regenerative braking system that is potentially imminent or has occurred, the generator torque is applied with approximately zero application of hydraulic torque; and subsequently, in response to the at least one of (a) the setpoint total braking torque exceeding the fixedly predefined or establishable threshold value and (b) the presence of the warning information, the generator torque is applied in combination with application of the hydraulic torque, so that the generator torque and the hydraulic torque in combination provide the setpoint total braking torque, wherein the application of the hydraulic torque includes transfer of sufficient brake fluid via at least one hydraulic actuator to at least one wheel brake cylinder of the regenerative braking system to close at least one air gap of the at least one wheel brake cylinder. ### Claim 2 (depends on 1) The method as recited in claim 1, wherein a setpoint volume of the brake fluid transferred via the at least one hydraulic actuator to the at least one wheel brake cylinder is established by taking into consideration at least one of an estimated and ascertained increased volume intake of at least one subarea of the braking system hydraulics. ### Claim 3 (depends on 1) The method as recited in claim 1, wherein a setpoint volume of the brake fluid transferred via the at least one hydraulic actuator to the at least one wheel brake cylinder is established by taking into consideration at least one of an estimated and ascertained friction value at at least one wheel of the vehicle. ### Claim 4 (depends on 1) The method as recited in claim 1, wherein a setpoint volume of the brake fluid transferred via the at least one hydraulic actuator to the at least one wheel brake cylinder is established by taking into consideration the at least one piece of warning information. ### Claim 5 (depends on 1) The method as recited in claim 1, wherein the application of the generator torque is performed such that, when the setpoint total braking torque is less than or equal to the maximally executable available generator braking torque: prior to the setpoint total braking torque exceeding the fixedly predefined or establishable threshold value, the generator torque is applied with approximately zero application of the hydraulic torque; and subsequently, in response to the setpoint total braking torque exceeding the fixedly predefined or establishable threshold value, the generator torque is applied in combination with the application of the hydraulic torque, so that the generator torque and the hydraulic torque in combination provide the setpoint total braking torque. ### Claim 6 (depends on 1) The method as recited in claim 1, wherein the application of the generator torque is performed such that, when the setpoint total braking torque is less than or equal to the maximally executable available generator braking torque: prior to the presence of warning information regarding the transition to the backup level of the regenerative braking system that is potentially imminent or has occurred, the generator torque is applied with approximately zero application of the hydraulic torque; and subsequently, in response to the presence of the warning information, the generator torque is applied in combination with the application of the hydraulic torque, so that the generator torque and the hydraulic torque in combination provide the setpoint total braking torque. ### Claim 7 A method for operating a regenerative braking system of a vehicle, comprising: activating at least one motor, having a generator mode, of the regenerative braking system taking into consideration a first information with regard to a setpoint total braking torque requested by a driver or an automatic speed control of the vehicle, and a second information with regard to an available generator braking torque which is maximally executable using the at least one motor employable in generator mode in such a way that if the setpoint total braking torque is executable at least partially by the maximally executable available generator braking torque, a generator braking torque which is less than or equal to the setpoint total braking torque and less than or equal to maximally executable available generator braking torque is applied to at least one of at least one wheel and at least one axle of the vehicle, with the aid of the at least one motor employable in the generator mode; wherein the application of the generator torque is performed such that, when the setpoint total braking torque is less than or equal to the maximally executable available generator braking torque: prior to at least one of (a) the setpoint total braking torque exceeding a fixedly predefined or establishable threshold value and (b) presence of warning information regarding a transition to a backup level of the regenerative braking system that is potentially imminent or has occurred, the generator torque is applied with approximately zero application of hydraulic torque; and subsequently, in response to the at least one of (a) the setpoint total braking torque exceeding the fixedly predefined or establishable threshold value and (b) the presence of the warning information, the generator torque is applied in combination with application of the hydraulic torque, so that the generator torque and the hydraulic torque in combination provide the setpoint total braking torque, wherein the application of the hydraulic torque includes transfer of sufficient brake fluid via at least one hydraulic actuator to at least one wheel brake cylinder of the regenerative braking system to close at least one air gap of the at least one wheel brake cylinder, and a setpoint volume of the brake fluid transferred via the at least one hydraulic actuator to the at least one wheel brake cylinder is established by taking into consideration at least one of an estimated and ascertained air quantity in at least one subarea of hydraulics of the braking system. ### Claim 8 A control unit for a regenerative braking system of a vehicle, comprising: an activation device designed to activate the at least one motor having a generator mode taking into consideration at least one provided predefined braking signal regarding a setpoint total braking torque requested by a driver or an automatic speed control of the vehicle and at least one provided information signal regarding an available generator braking torque which is maximally executable without overcharging a battery of the vehicle using the at least one motor, employable in generator mode, of the regenerative braking system in such a way that when the setpoint total braking torque is executable at least partially by the maximally executable available generator braking torque, a generator braking torque which is less than or equal to the setpoint total braking torque and less than or equal to the maximally executable available generator braking torque is applicable to at least one of at least one wheel and at least one axle of the vehicle, with the aid of the at least one motor employable in generator mode; wherein the activation device is configured to perform the application of the generator torque such that, when the setpoint total braking torque is less than or equal to the maximally executable available generator braking torque: prior to at least one of (a) the setpoint total braking torque exceeding a fixedly predefined or establishable threshold value and (b) presence of warning information regarding a transition to a backup level of the regenerative braking system that is potentially imminent or has occurred, the generator torque is applied with approximately zero application of hydraulic torque; and subsequently, in response to the at least one of (a) the setpoint total braking torque exceeding the fixedly predefined or establishable threshold value and (b) the presence of the warning information, the generator torque is applied in combination with application of the hydraulic torque, so that the generator torque and the hydraulic torque in combination provide the setpoint total braking torque, wherein the application of the hydraulic torque includes transfer of sufficient brake fluid via at least one hydraulic actuator to at least one wheel brake cylinder of the regenerative braking system to close at least one air gap of the at least one wheel brake cylinder. ### Claim 9 (depends on 8) The control unit as recited in claim 8, wherein the activation device is designed to establish a setpoint volume variable with regard to a setpoint volume of the brake fluid which is to be transferred via the at least one hydraulic actuator to the at least one wheel brake cylinder taking into consideration at least one estimated and/or ascertained increased volume intake of at least one subarea of the braking system hydraulics. ### Claim 10 (depends on 8) The control unit as recited in claim 8, wherein the activation device is additionally designed to establish the setpoint volume variable taking into consideration at least one estimated and/or ascertained friction value at at least one wheel of the vehicle. ### Claim 11 (depends on 8) The control unit as recited in claim 8, wherein the activation device is additionally designed to establish the setpoint volume variable taking into consideration the at least one piece of warning information. ### Claim 12 A regenerative braking system for a vehicle including a control unit for a regenerative braking system of a vehicle, the control unit comprising: an activation device designed to activate the at least one motor having a generator mode taking into consideration at least one provided predefined braking signal regarding a setpoint total braking torque requested by a driver or an automatic speed control of the vehicle and at least one provided information signal regarding an available generator braking torque which is maximally executable without overcharging a battery of the vehicle using the at least one motor, employable in generator mode, of the regenerative braking system in such a way that when the setpoint total braking torque is executable at least partially by the maximally executable available generator braking torque, a generator braking torque which is less than or equal to the setpoint total braking torque and less than or equal to the maximally executable available generator braking torque is applicable to at least one of at least one wheel and at least one axle of the vehicle, with the aid of the at least one motor employable in generator mode; wherein the activation device is configured to perform the application of the generator torque such that, when the setpoint total braking torque is less than or equal to the maximally executable available generator braking torque: prior to at least one of (a) the setpoint total braking torque exceeding a fixedly predefined or establishable threshold value and (b) presence of warning information regarding a transition to a backup level of the regenerative braking system that is potentially imminent or has occurred, the generator torque is applied with approximately zero application of hydraulic torque; and subsequently, in response to the at least one of (a) the setpoint total braking torque exceeding the fixedly predefined or establishable threshold value and (b) the presence of the warning information, the generator torque is applied in combination with application of the hydraulic torque, so that the generator torque and the hydraulic torque in combination provide the setpoint total braking torque, wherein the application of the hydraulic torque includes transfer of sufficient brake fluid via at least one hydraulic actuator to at least one wheel brake cylinder of the regenerative braking system to close at least one air gap of the at least one wheel brake cylinder.