# US 10,308,120 B2 · Optimizing regenerative braking efficiency in a hybrid vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,308,120 B2 - Document ID: US10308120B2 - Status: Granted - Kind: B2 - Application number: 15/485,845 - Filed: 2017-04-12 - Published: 2018-10-18 - Granted: 2019-06-04 - Earliest claimed: 2017-04-12 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Yanan Zhao; Ming Lang Kuang; Zheng Liu - Web page: https://patentgrep.com/patent/US10308120B2 ## CPC - B60L 7/26: Controlling the braking effect - B60L 7/18: Controlling the braking effect (B60L7/12, B60L7/14, B60L7/16 take precedence) - 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)} - B60L 2240/12: Speed - B60L 2240/16: longitudinal - B60L 2240/423: Torque - B60L 2240/486: Operating parameters - B60L 2240/54: related to batteries - B60L 2250/26: by pedal actuation - B60T 2201/02: Active or adaptive cruise control system; Distance control - B60T 2201/022: Collision avoidance systems - B60T 2260/04: Automatic transmission - B60T 2270/604: Merging friction therewith; Adjusting their repartition - Y02T 10/64: Electric machine technologies in electromobility - 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 - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An autonomous or semi-autonomous vehicle is provided that is capable of braking itself without a driver depressing the brake pedal. The vehicle has a powertrain that includes an engine, a transmission, and a motor with a connected battery to provide regenerative braking capabilities. Friction brakes are provided to apply when necessary, such as when the battery has a high state of charge and further regenerative braking would overcharge the battery. The braking may be activated in response to a sensor detecting a distance to an object in front of the vehicle. A vehicle controller is programmed to automatically control amounts of regenerative braking and friction braking during a braking event based on a comparison between a regenerative torque limit of the powertrain and a desired brake torque over the brake event to safely brake the vehicle during the brake event. ## Claims ### Claim 1 A vehicle comprising: a powertrain including a battery and a motor/generator configured to perform regenerative braking; and a controller programmed to request regenerative braking without friction braking until an end or near end of an upcoming braking event in response to a magnitude of a powertrain regenerative torque limit predicted to exceed a magnitude of average desired brake torque for a portion of braking event. ### Claim 2 (depends on 1) The vehicle of claim 1, wherein the controller is programmed to request the regenerative braking without the friction braking in response to the magnitude of the powertrain regenerative torque limit predicted to exceed the magnitude of average desired brake torque for only a portion and not the entirety of the braking event. ### Claim 3 (depends on 1) The vehicle of claim 1, wherein the powertrain regenerative torque limit is based on a regenerative torque limit of the motor/generator, a state of charge of the battery, and a regenerative limit of a transmission that varies depending on an operating gear of the transmission. ### Claim 4 (depends on 1) The vehicle of claim 1, wherein the average desired brake torque is an average of a brake torque necessary to properly stop or slow the vehicle over a distance that depends on a location of a detected external object. ### Claim 5 (depends on 1) The vehicle of claim 1, wherein the controller is further programmed to request the regenerative braking without the friction braking until the end of the braking event based on a magnitude of an average of the powertrain regenerative torque limit predicted to exceed a magnitude of an average desired brake torque for the braking event. ### Claim 6 (depends on 1) The vehicle of claim 1, wherein the vehicle further comprises friction brakes, and the controller is further programmed to initiate the friction braking while reducing the regenerative braking at the end or near end of the braking event. ### Claim 7 (depends on 1) The vehicle of claim 1, further comprising a sensor configured to detect a distance to an external object, and the controller is further programmed to request the regenerative braking without friction braking in response to the distance being below a threshold. ### Claim 8 A vehicle comprising: a powertrain including a battery, a motor/generator configured to perform regenerative braking, and a transmission; friction brakes; and a controller programmed to hold friction braking steady while modulating a magnitude of the regenerative braking during a braking event in response to a magnitude of average desired brake torque predicted to exceed a magnitude of powertrain regenerative torque limit for the entire braking event. ### Claim 9 (depends on 8) The vehicle of claim 8, further comprising a sensor configured to detect a distance to an external object, and the controller is further programmed to initiate the friction braking and regenerative braking in response to the distance being below a threshold. ### Claim 10 (depends on 9) The vehicle of claim 9, wherein the controller is further programmed to alter the threshold based on a speed of the vehicle. ### Claim 11 (depends on 8) The vehicle of claim 8, wherein the regenerative torque limit is based on a regenerative torque limit of the motor/generator, a state of charge of the battery, and a regenerative limit of the transmission that varies depending on an operating gear of the transmission. ### Claim 12 (depends on 8) The vehicle of claim 8, wherein the average desired brake torque is an average of a brake torque necessary for the entire braking event. ### Claim 13 (depends on 8) The vehicle of claim 8, wherein the controller is programmed to modulate the magnitude of the regenerative braking such that a difference between the magnitude of regenerative braking and a commanded brake torque remains generally constant. ### Claim 14 (depends on 8) The vehicle of claim 8, further comprising an engine selectively coupled to the motor/generator via a clutch. ### Claim 15 An autonomous vehicle comprising: a powertrain including: an engine, a transmission, and a motor separately selectively coupled to the engine and the transmission and capable of performing regenerative braking; fiction brakes; a sensor configured to detect a distance to an object in front of the vehicle; and a controller programmed to automatically control amounts of regenerative braking and friction braking during a braking event based on a predictive comparison at a beginning of the braking event between a regenerative torque limit of the powertrain and an average desired brake torque until an end of the braking event dependent on the distance. ### Claim 16 (depends on 15) The vehicle of claim 15, wherein the controller is further programmed to hold the friction braking constant and modulate the regenerative braking during the braking event. ### Claim 17 (depends on 15) The vehicle of claim 15, wherein the regenerative torque limit of the powertrain is dependent upon a gear ratio the transmission is operating in. ### Claim 18 (depends on 15) The vehicle of claim 15, wherein the controller is further programmed to control the regenerative braking and the friction brakes based on a desired average brake torque necessary to stop or slow the vehicle within the distance. ### Claim 19 (depends on 18) The vehicle of claim 18, wherein the desired average brake torque is derived from a desired deceleration based on the distance. ### Claim 20 (depends on 18) The vehicle of claim 18, wherein the controller is further programmed to command a relatively constant amount of frictional braking while modulating the regenerative braking in response to a magnitude of the desired average brake torque exceeding a magnitude of the regenerative torque limit of the powertrain for the braking event.