Method, apparatus and article for vibration compensation in electric drivetrains

• US 20050253543A1
• Filed: 03/30/2005
• Published: 11/17/2005
• Est. Priority Date: 03/30/2004
• Status: Active Grant

• Current Assignee: Continental Automotive Systems, Inc. (Continental AG)
• Original Assignee: Continental Automotive Systems US Incorporated (Continental AG)
• Inventors: Reddy, Vinod, Hampo, Richard J., Nallapa, Venkatapathi R., Soudier, Christophe
• Granted Patent: US 7,495,403 B2
• Time in Patent Office: Days
• US Class Current: 318/432
• CPC Class Codes: H02P 21/05 specially adapted for damping motor oscillations, e.g. for reducing hunting

Abstract

A torque current peak compensation value is subtracted from a torque current reference value, where the torque current peak compensation value is based at least in part on a determined peak of vibration. A torque current compensation value is subtracted from the results to produce an adjusted torque current reference value.

Claims

1. A method of vibration compensation, the method comprising:

applying a hardware limitation to a torque command to produce a torque request;

converting the torque request to a torque current value;

determining a peak of vibration;

applying an adaptation degree value to the torque current value to produce a torque current request value wherein the adaptation degree value is based at least in part on the determined peak of vibration;

applying an electrical limitation to the torque current request value to produce a torque current reference value;

subtracting a torque current peak compensation value from the torque current reference value, wherein the torque current peak compensation value is based at least in part on the determined peak of vibration;

subtracting a torque current compensation value from the results of the subtraction of the torque current peak compensation value from the torque current reference value to produce an adjusted torque current reference value;

pulse width modulating the adjusted torque current reference value to produce pulse width modulated signals; and

providing the pulse width modulated signals to drive a power converter.

2. The method of claim 1 wherein determining a peak of vibration comprises:

setting a torque current compensation maximum value equal to the torque current compensation value if the torque current compensation value is greater than the torque current compensation maximum value; and

setting a torque current compensation minimum value equal to the torque current compensation value if the torque current compensation value is less than the torque current compensation minimum value.

3. The method of claim 2 wherein determining a peak of vibration further comprises:

if the torque current compensation value is not greater than the torque current compensation maximum value and if the torque current compensation value is not less than the torque current compensation minimum value,

setting the torque current compensation maximum value equal to the product of the torque current compensation value and a multiplicand between zero and one; and

setting the torque current compensation minimum value equal to the torque current compensation value if the torque current compensation value is less than the torque current compensation minimum value.

4. The method of claim 3 wherein determining a peak of vibration further comprises:

determining if a compensation function is disabled; and

if the compensation function is disabled,

setting the torque current compensation maximum value equal to zero; and

setting the torque current compensation minimum value equal to zero.

5. The method of claim 1, further comprising:

setting a present peak value equal to an absolute value of a present torque current compensation value if the present torque current compensation value is greater than a previous peak value.

6. The method of claim 5, further comprising:

setting the present peak value equal to a summation of the previous peak value minus a product of a constant and the previous peak value wherein the constant is between zero and one.

7. The method of claim 6 wherein the constant is approximately 0.995.

8. A system for controlling an alternating current machine, the system comprising:

a torque to current conversion module configured to generate a torque current signal in response to a torque command signal;

a pulse width modulation module configured to receive a reference signal and to produce a pulse width modulated signal; and

a vibration compensation module configured to generate a torque current compensation signal, a torque current peak compensation signal and an adaptation degree signal based at least in part on a vibration signal, wherein the system is configured to produce the reference signal based at least in part on the torque current signal, the torque current compensation signal, the torque current peak compensation signal and the adaptation degree signal.

9. The system of claim 8, further comprising:

a hardware limitation module coupled to the torque to current conversion module and configured to produce the torque command signal.

10. The system of claim 8, further comprising:

a multiplier configured to multiply the torque current signal by the adaptation degree signal and to produce a multiplier output signal;

an electrical limitation module configured to receive the multiplier output signal and to produce an electrical limitation output signal;

a first summer configured to subtract the torque current peak compensation signal from the electrical limitation output signal and to produce a first summer output signal; and

a second summer configured to subtract the torque current compensation signal from the first summer output signal and to produce the reference signal.

11. A method of vibration compensation, the method comprising:

converting a torque request to a torque current signal;

generating a torque current compensation signal, a torque current peak compensation signal and an adaptation degree signal; and

adjusting the torque current signal based at least in part on the torque current compensation signal, the torque current peak compensation signal and the adaptation degree signal.

12. The method of claim 11 wherein generating an adaptation degree signal comprises implicitly dividing two numbers.

13. The method of claim 11 wherein the adaptation degree signal is based at least in part on a vibration signal.

14. The method of claim 11 wherein the torque current compensation signal is based at least in part on a vibration signal.

15. The method of claim 14 wherein the vibration signal is a speed signal.

16. A system for controlling an alternating current machine, comprising:

means for converting a torque request to a torque current signal;

means for generating a torque current peak compensation signal;

means for adjusting the torque current signal coupled to the means for generating a torque current peak compensation signal and the means for converting a torque request to a torque current signal; and

means for generating a pulse width modulated signal coupled to the means for adjusting the torque current signal.

17. The system of claim 16 wherein the means for adjusting the torque current signal comprises means for applying an electrical limitation and the means for generating a torque current peak compensation signal is configured to generate a torque current compensation signal, an adaptation degree signal, and a torque current peak compensation signal, wherein the means for adjusting the torque current signal is configured to:

multiply the torque current signal by the adaptation degree signal, generating a first adjusted signal;

apply the electrical limitation to the first adjusted signal, producing a second adjusted signal;

subtract the torque current peak compensation signal from the second adjusted signal, producing a third adjusted signal; and

subtract the torque current compensation signal from the third adjusted signal.

18. The system of claim 17 wherein the means for generating a torque current peak compensation signal comprises means for implicitly dividing two numbers.

19. A computer-readable memory medium storing instructions for causing a control system to facilitate vibration compensation by:

determining a vibration value;

generating an adaptation degree value based at least in part on the vibration value;

generating a torque current compensation value based at least in part on the vibration value;

generating a torque current peak compensation value; and

adjusting a torque current reference value based on the adaptation degree value, the torque current compensation value and the torque current peak compensation value.

20. The computer-readable memory medium of claim 19, the stored instructions further comprising instructions for causing the control system to facilitate vibration compensation by:

applying an electrical limitation during adjustment of the torque current reference value.