Ford Global Technolgoies, LLC

Chris Teslak

Cliff Carlson

Chuanchi Tang

Ron Kepner

Peter Chalk

A system for braking the wheels of a hydraulic hybrid vehicle includes a brake pedal having a range of pedal displacement including a deadband displacement range, an accumulator containing fluid at relatively high pressure, a reservoir containing fluid at lower pressure, a pump/motor having variable volumetric displacement connected to the accumulator and reservoir, and driveably connected to the wheels; a system responsive to brake pedal displacement in the deadband range for placing the pump/motor in a pump state wherein the pump/motor is driven by the wheels and pumps fluid from the reservoir to the accumulator; and a control valve for changing the volumetric displacement of the pump/motor in response to displacement of the brake pedal.

Deadband regenerative braking control for hydraulic hybrid vehicle powertrain

A system for replenishing a source of pressurized fluid for use in driving the wheels of a motor vehicle includes an accumulator containing fluid at relatively high pressure; a reservoir containing fluid at lower pressure; an engine driveably connected to the wheels and having a variable torque output; a pump/motor driveably connected to the wheels, including an inlet and an outlet, and having a variable volumetric displacement for pumping fluid between the accumulator and the reservoir; and a controller for determining a current cruise charge pressure limit for the accumulator, determining a desired magnitude of pump/motor torque with which to pump fluid to the accumulator, determining a desired magnitude of engine torque with which to drive the pump/motor at the desired magnitude of pump/motor torque, and controlling the engine to produce the desired magnitude of engine torque, to drive the pump/motor in a pumping mode at the desired magnitude of pump/motor torque, and to pump fluid to the accumulator from the reservoir.

Charging a fluid accumulator while operating a hybrid vehicle powertrain including an engine and a pump/motor

A system according to this invention opposes creep in a hydraulic hybrid motor vehicle. An accumulator contains fluid at high pressure, and a reservoir contains fluid at lower pressure. An engine produces positive torque at the wheels during an engine idle condition, and a pump/motor, driveably connected to the wheels and the engine, has a variable volumetric displacement pumps fluid to the accumulator from the reservoir. A control system determines a magnitude of negative torque transmitted from the wheels to the pump/motor that would exceed the magnitude of positive torque, determines the volumetric displacement of the pump/motor corresponding to the magnitude of negative torque, changes the displacement of the pump/motor to the required displacement, and operates the pump/motor as a pump driven by negative torque from the wheels to pump fluid from the reservoir to the accumulator.

Wheel creep control of hydraulic hybrid vehicle using regenerative braking

A motor vehicle powertrain system according to this invention controls the magnitudes of torque produced by multiple power sources that drive the vehicle wheels. The system includes a source of pressurized fluid, and a pump/motor driveably connected to the wheels, which is driven in a motoring mode by fluid from the fluid source and has a variable volumetric displacement that changes in response to displacement of the accelerator pedal. An engine, driveably connected to the wheels, includes a throttle that opens and closes in response to displacement of the accelerator pedal. A controller controls operation of the engine and pump/motor such that they produce torque at various magnitudes. The system determines a magnitude of desired wheel torque, a maximum available engine wheel torque, a maximum available pump/motor wheel torque, a difference in magnitude between the desired wheel torque and the maximum available pump/motor wheel torque, operates the pump/motor as a motor such that the pump/motor produces a magnitude of wheel torque that is equal to the lesser of the desired wheel torque and the maximum available pump/motor wheel torque, and operates the engine such that the engine produces a magnitude of wheel torque that is equal to the lesser of the maximum available engine wheel torque and the difference in torque magnitude.

Controlling a hydraulic hybrid vehicle powertrain having an internal combustion engine and a hydraulic pump/motor

A system for transmitting power hydraulically to and from the wheels of a motor vehicle includes an accumulator containing fluid at relatively high pressure, a reservoir containing fluid at lower pressure, and a pump/motor driveably connected to the wheels and having a variable volumetric displacement for pumping fluid between the accumulator and the reservoir. A first circuit connects the inlet to the reservoir and the outlet to the accumulator. A second circuit includes a first path having a low flow rate capacity, a second path having a higher flow rate capacity. A controller switches between pumping operation and motoring operation, opens and closes the first path during motoring operation, and reduces the displacement before switching between pumping operation and motoring operation.

Growing community of inventors

Plymouth, MI, United States of America

Chris Teslak