Method to maximize available regeneration while maintaining linear vehicle deceleration rate

• Main Authors: HAWKINS MATTHEW, MCGROGAN SEAN W, ALDRICH, III WILLIAM L
• Format: Patent
• Language: English
• Published: 05.04.2016
• Subjects: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE ORDIFFERENT FUNCTION; CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORSOR DYNAMO-ELECTRIC CONVERTERS; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRIC EQUIPMENT OR PROPULSION OF ELECTRICALLY-PROPELLEDVEHICLES; ELECTRICITY; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES, IN GENERAL; GENERATION; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; PERFORMING OPERATIONS; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TOTHE CONTROL OF A PARTICULAR SUB-UNIT; TRANSPORTING; VEHICLES IN GENERAL

A method for maximizing regenerative energy captured by an electric machine in a powertrain including an engine, the electric machine and a transmission device configured to transfer torque through a driveline includes detecting an operator brake request and monitoring a time between the detected operator brake request and a preceding operator brake request that was last detected. A maximized regenerative deceleration event is initiated if the time exceeds a predetermined threshold time that includes monitoring a current fixed gear ratio that is selected from among a plurality of fixed gear ratios of the transmission device when the operator brake request is detected and applying a magnitude of torque at the axle that is sufficient for achieving a maximum capability of the electric machine to capture regenerative energy in the current fixed gear ratio.