Control system for improved transient response in a variable-geometry turbocharger
AssigneeHoneywell International Inc.
InventorSamir S. Ahmad
Life of this patent
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Abstract
A control system for a variable-geometry turbocharger includes a supervisor logic (12) selecting a pulse control output (24) for large variation of desired and previous control signal inputs exceeding a threshold differential and a normal control signal (26) for small control signal input changes. The control system calculates an amplitude and duration for the pulse control output based on input control signal variation or the actual versus desired position of the variable-geometry system in the turbocharger.
Claims25
A control system for controlling a variable-geometry mechanism in a turbocharger for an engine, comprising:
- a logic arrangement structured and arranged to sample a desired control value representing a desired operating condition in which the turbocharger is to be operated, and to sample a previous desired control value representing the desired control value determined in a previous sample period, the logic arrangement being further structured and arranged to determine a first difference parameter as the difference between the desired control value and the previous desired control value and to produce a control signal output based on said first difference parameter, such that the control signal output has a first value when said first difference parameter is greater than a predetermined first threshold and has a second value different from the first value when said first difference parameter is not greater than the predetermined first threshold, and wherein the logic arrangement is structured and arranged to provide the first value as a pulse of predetermined amplitude and duration.
A control system for a variable-geometry turbocharger, comprising:
- a logic circuit having a first input, a second input, and an output, the logic circuit being structured and arranged to calculate a difference between the first and second inputs and to selectively provide either a first value or a second value to the output depending on the value of said difference, the logic circuit being further structured and arranged to produce a pulse control signal;
- means for providing a desired control signal to the first input;
- means for providing a previous control signal to the second input;
- a controller structured and arranged to provide a normal control signal;
- a switch receiving the normal control signal and the pulse control signal and having a switch output, the switch being responsive to the logic circuit output and providing the pulse control signal to the switch output responsive to the first value on the logic circuit output and providing the normal control signal to the switch output responsive to the second value on the logic circuit output;
- and
- an actuator connected to the switch output, the actuator operable to adjust a variable-geometry mechanism of the turbocharger.
A method for controlling a variable-geometry mechanism in a turbocharger for an engine, comprising the steps of:
- sampling a desired control value representing a desired operating condition in which the turbocharger is to be operated;
- sampling a previous desired control value representing the desired control value determined in a previous sample period;
- determining a first difference parameter as the difference between the desired control value and the previous desired control value;
- and
- supplying a control signal output to an actuator for the variable-geometry mechanism based on said first difference parameter, such that the control signal output has a first value when said first difference parameter is greater than a predetermined first threshold and has a second value different from the first value when said first difference parameter is not greater than the predetermined first threshold, said first value being supplied in the form of a pulse of predetermined amplitude and duration.
Dependencies are inferred from the claim text.