Vehicle propulsion torque control systems and methods
AssigneeFord Global Technologies, LLC
InventorsJason Meyer, Jeffrey Allen Doering, Maruthi Thiruninravur Ravichandran
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Abstract
A vehicle propulsion system configured to generate wheel torque includes an engine arranged to output a first propulsion torque to a transmission and an electric motor arranged to output a second propulsion torque downstream of the transmission. The vehicle propulsion system also includes a controller programmed to, in response to detecting a lash crossing associated with one of the electric motor and the transmission, set a torque slew rate of the other one of the electric motor and transmission such that each of the electric motor and transmission undergoes lash crossings at different points in time.
Claims16
A vehicle propulsion system to generate wheel torque comprising:
- an engine arranged to output a first propulsion torque to a transmission;
- an electric motor arranged to output a second propulsion torque downstream of the transmission;
- and
- a controller programmed to,
- in response to detecting a lash crossing associated with one of the electric motor and the transmission, set a torque slew rate of the other one of the electric motor and transmission to prevent lash crossing of the other of the motor and transmission during the detected lash crossing, and
- in response to a first slew rate of one of the engine and electric motor being positive and a second slew rate of the other of the engine and electric motor being negative, limit the first and second slew rates to be within a predetermined threshold of a desired wheel torque slew rate.
A vehicle propulsion system comprising:
- an engine arranged to output a first propulsion torque to a final drive unit through a transmission;
- an electric motor arranged to output a second propulsion torque to the final drive unit through a motor gearbox downstream of the transmission;
- an integrated starter generator (ISG) arranged to output a third propulsion torque to the final drive unit through the transmission;
- and
- a controller programmed to
- allocate output between the first, second, and third propulsion torques to satisfy a desired wheel torque and cause the transmission, motor gearbox, and the final drive unit to each undergo a lash crossing at different times,
- cause the engine to undergo a lash crossing prior to the electric motor undergoing a lash crossing during acceleration, and
- in response to a first slew rate of one of the engine and ISG being positive and a second slew rate of the other of the engine and ISG being negative, limit slew rates of each of the engine and ISG based on a maximum allowed torque swapping rate.
A method for controlling propulsion system torque output comprising:
- setting a target torque output allocation between an engine and an electric motor to satisfy a driver torque demand, wherein the engine is upstream of a transmission and the electric motor is downstream of the transmission;
- in response to one of an engine connection and an electric motor connection undergoing a lash crossing, setting a torque slew rate of the other of the engine and electric motor to cause each of the engine connection and electric motor connection to undergo lash crossings at different points in time;
- and
- in response to a first slew rate of one of the engine and electric motor being positive and a second slew rate of the other of the engine and electric motor being negative, limiting the first and second slew rates to be within a predetermined threshold of a desired wheel torque slew rate.
Dependencies are inferred from the claim text.