Method and apparatus for adaptive motor speed control
A different adaptive control method is used to control a motor during each of two or more phases of motor operation. Thus, in a first phase of motor operation the motor is controlled using a first adaptive control method, in a second phase of motor operation the motor is controlled using a second adaptive control method, and so forth. The motor can be controlled in this manner in any number of phases, in which the motor is used for any of a number of corresponding purposes. The method used in each phase can be optimized to suit that type of operation without compromising operation during other phases.
1. A method for controlling a motor comprising:
controlling the motor in response to a first adaptive control method during a first phase of motor operation, wherein the first phase is an acceleration phase, wherein controlling the motor in response to the first adaptive control method comprises measuring a first motor speed, determining a first control value using the first motor speed, and providing a first input signal to the motor based on the first control value; and
controlling the motor in response to a second adaptive control method during a second phase of motor operation, wherein controlling the motor in response to the second adaptive control method comprises measuring a second motor speed, determining a second control value using the second motor speed, and providing a second input signal to the motor based on the second control value.
2. The method of claim 1 , wherein the second phase is a constant-speed phase.
3. The method of claim 1 , wherein the second phase is a deceleration phase.
4. The method of claim 1 , wherein:
the second phase is a constant-speed phase and occurs after the first phase; and
the method further comprises:
detecting when the motor reaches a target speed during the first phase; and
controlling the motor in response to an adaptive control method other than the second adaptive control method during a deceleration phase of motor operation occurring after the second phase.
5. The method of claim 4 , wherein the adaptive control method other than the second adaptive control method is the first adaptive control method.
6. The method of claim 5 , wherein the second adaptive control method comprises a proportional-integral-derivative (PID) method.
7. The method of claim 6 , further comprising:
storing a steady-state value produced by the PID method in the constant-speed phase, the steady-state value remaining stored while the motor operates during a subsequent deceleration phase and a subsequent acceleration phase; and
initializing a value in the PID method to the stored steady-state value when the motor returns to the constant-speed phase.
8. The method of claim 1 , wherein determining the first or the second control value comprises obtaining the control value from control logic.
9. The method of claim 8 , wherein the control logic comprises a look-up table.
10. A system for controlling a motor comprising:
a motor speed sensor means for measuring motor speed;
a motor power means;
first phase adaptive control means for causing the motor power means to produce a first signal in response to measured motor speed in accordance with a first adaptive control method and apply the first signal to the motor during a first phase of motor operation, wherein the first phase is an acceleration phase; and
second phase adaptive control means for causing the motor power means to produce a second signal in response to measured motor speed in accordance with a second adaptive control method and apply the second signal to the motor during a second phase of motor operation.
11. The system of claim 10 , wherein the first phase adaptive control means and second phase adaptive control means are included at least partly in a programmed microprocessor.
12. The system of claim 10 , wherein the second phase is a constant-speed phase.
13. The system of claim 10 , wherein the second phase is a deceleration phase.
14. The system of claim 10 , wherein at least one of the first phase adaptive control means and the second phase adaptive control means comprises a look-up table.
15. The system of claim 10 , wherein at least one of the first phase adaptive control means and the second phase adaptive control means comprises a proportional-integral-derivative (PID) means for performing a proportional-integral-derivative (PID) method.
16. A system for controlling a motor comprising:
a motor speed sensor configured to measure motor speed;
a motor power system operable in at least a first phase and a second phases, wherein the first phase is an acceleration phase; and
a processing device in communication with the motor speed sensor and the motor power system, the processing device comprising a first adaptive control and a second adaptive control, the first and second adaptive controls adapted to receive the measured motor speed during the first and second phases respectively, and further adapted to provide a control value, based on the measured motor speed, to the motor power system during the first and second phases.
17. The system of claim 16 , wherein the second phase is a constant-speed phase.
18. The system of claim 16 , wherein at least one of the first and second adaptive controls comprises a look-up table.
19. The system of claim 16 , wherein at least one of the first and second adaptive controls comprises a proportional-integral-derivative (PID) control.
20. The system of claim 16 , wherein the motor power system is further operable in a third phase; and wherein the processing device further comprises a third adaptive control adapted to receive the measured motor speed during the third phase and provide a control value, based on the measured motor speed, to the motor power system during the third phase.
21. The system of claim 20 , wherein the third phase is a deceleration phase.
22. The system of claim 20 , wherein the third adaptive control comprises a look-up table.
23. The system of claim 20 , wherein the third adaptive control comprises a proportional-integral-derivative (PID) control.
24. The system of claim 16 , wherein one of the first and second adaptive controls comprises a look-up table and the other of the first and second adaptive controls comprises a proportional-integral-derivative (PID) control.
25. The system of claim 24 , wherein the second phase is a constant-speed phase.
26. The system of claim 24 , wherein the first adaptive control comprises the look-up table and the second adaptive control comprises the PID control.