Claims
- 1. In a VCT system having a feedback loop for controlling a phaser angular relationship, said system including a controller having a control law disposed to receive a plurality of set point values and a plurality of feed back values, said control law comprising:
a) a computation block for receiving said plurality of set point values as inputs, said computation block outputting a first output and a second output; b) a first summer for summing said first output and said plurality of feed back values to produce a first sum; c) a phase integrator and a phase compensator receiving said first sum and derivatives thereof outputting a processed value; d) a amplifier amplifying said second output by a predetermined scale; and e) a second summer for summing said processed value and the amplified second output to produce a second sum.
- 2. The control law of claim 1, wherein said first output includes mode information.
- 3. The control law of claim 1, wherein said second output includes slope information of said plurality of set point values.
- 4. A VCT system, comprising:
sensors for receiving position information of cam and crank shafts respectively; a phaser for adjusting small changes between said crank and cam shafts; an actuator engaging said phaser; a controller for controlling said actuator, said controller including a control law, wherein said control law includes:
a computation block for receiving said plurality of set point values as inputs, said computation block outputting a first output and a second output; a first summer for summing said first output and said plurality of feed back values to produce a first sum; a phase integrator and a phase compensator receiving said first sum and derivatives thereof outputting a processed value; a amplifier amplifying said second output by a predetermined scale; and a second summer for summing said processed value and the amplified second output to produce a second sum.
- 5. The VCT system of claim 4, wherein said first output includes mode information.
- 6. The VCT system of claim 4, wherein said second output includes slope information of said plurality of set point values.
- 7. The VCT system of claim 4, wherein said actuator is a solenoid.
- 8. In a VCT system having a feedback loop for controlling a phaser relationship, said system including a controller having a control law disposed to receive a plurality of set point values and a plurality of feed back values, said control law being disposed to perform a method comprising the steps of:
a) providing a set point change; b) determining a mode of said VCT system among a set of four modes; and c) selectively applying a filter upon said set point change, thereby reducing overshoot caused by set point change.
- 9. The method of claim 8 further comprising calculating feedforward signal.
- 10. The method of claim 8, wherein said set of four modes includes:
a first mode wherein there is no substantial change in set point values; a second mode wherein there is a substantial increase in set point values; a third mode wherein there is a substantial decrease in set point values; and a fourth mode wherein the measured position of phaser is close to the set point.
- 11. The method of claim 10, wherein said filter is applied when said VCT system is under said fourth mode.
REFERENCE TO RELATED APPLICATIONS
[0001] This application claims an invention which was disclosed in Provisional Application No. 60/389,199, filed Jun. 17, 2002, entitled “Control Method for Achieving Expected VCT Actuation Rate Using Set Point Rate Limiter”. The benefit under 35 USC §119(e) of the United States provisional application is hereby claimed, and the aforementioned application is hereby incorporated herein by reference.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60389199 |
Jun 2002 |
US |