Sliding mode controller for engine thermal management
OwnerVenkat Sunil Tanneru, Micahel Uchanskiinventors
Life of this patent
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Abstract
A sliding mode controller for one or more valves in an engine induction or exhaust system provides improved thermal control over an engine. Double discrete variable rate filters generate position and velocity profiles for various intake and exhaust valves. Alternatively, double discrete fixed rate filters may be used to generate position and velocity profiles. A control law includes a Signum function and is modified with a “boundary layer” to control valve chattering. Alternatively, gain scheduling may be used to remove valve chattering. A low pass filter on the controller output can be used to remove chattering phenomena.
Claims17
A sliding mode controller for one or more valves in an engine induction or exhaust system comprising:
- filter means for generating position and velocity profiles for the valve or valves;
- and
- means for controlling valve chattering including one or more of means for generating a boundary layer and a low pass filter for processing a control output to be applied to a valve actuator.
A method of valve control in a fluid control system comprising the steps of:
- generating position and velocity profiles for a valve or valves;
- and
- controlling valve chattering by generating a boundary layer or by applying a valve positioning signal to a low pass filter.
A control apparatus for an exhaust system for a motor vehicle engine and an induction system for the motor vehicle engine, the control apparatus comprising:
- a thermal management valve in the exhaust system;
- an exhaust gas recirculation control valve for coupling exhaust gas from the exhaust system to the induction system;
- a controller;
- a profile generator executed on the controller for generating target position control inputs for the thermal management valve and the exhaust gas recirculation valve and for generating target velocity control inputs for the valves during movement between target positions;
- means for calculating a sliding mode control surface combining an error on valve positions and velocity;
- means for calculating a control law to drive the sliding mode control surface toward zero to minimize the error on valve position and valve velocity between position;
- and
- position feedback signals for the exhaust gas recirculation control valve and the thermal management valve.
A method for controlling motor vehicle engine exhaust and induction system valves including a thermal management valve, an exhaust gas recirculation control valve for coupling exhaust gas from the exhaust system to the induction system and an induction throttle, the method including the steps of:
- responsive to a valve position setpoint generating target position control inputs for the thermal management valve and the exhaust gas recirculation valve and for generating target velocity control inputs for the valves during movement between target positions;
- calculating a sliding mode control surface combining an error on valve positions and velocity;
- calculating a control law to drive the sliding mode control surface toward zero to minimize the error on valve position and valve velocity between position;
- and
- generating position feedback signals for the exhaust gas recirculation control valve and the thermal management valve.
Dependencies are inferred from the claim text.