Method and device for controlling backlash

• US 20080004724A1
• Filed: 05/18/2007
• Published: 01/03/2008
• Est. Priority Date: 05/18/2006
• Status: Abandoned Application

• Current Assignee: Saab AB
• Original Assignee: Saab AB
• Inventors: Stahl-Gunarsson, Karin
• Application Number:
  US11/802,035
• Publication Number:
  US 20080004724A1
• Time in Patent Office: Days
• US Class Current: 700/71
• CPC Class Codes: G05B 19/404 characterised by control arrangements for compensation, e.g. for backlash, overshoot, tool offset, tool wear, temperature, machine construction errors, load, inertia G05B19/19, G05B19/41 take precedence
• CPC Class Codes: G05B 2219/41032 Backlash
• CPC Class Codes: G05B 2219/41434 Feedforward FFW

Abstract

A method for compensating for backlash of a control system. An input signal is provided to the system. The system produces an output signal. An error signal is created from a comparison between the input signal and the output. The error signal is fed to the input signal to produce a compensated input. The compensated input signal is fed to the backlash to produce a compensated output signal. A control system compensates for backlash. A computer programme includes a programme code. A computer programme product includes a program code stored on a, by a computer readable, media. A computer programme product directly storable in an internal memory into a computer includes a computer programme.

Claims

1. A method for compensating for backlash of a control system, the method comprising:

providing an input signal, the system producing an output signal;

creating an error signal from a comparison between the input signal and the output signal;

feeding the error signal to the input signal to produce a compensated input signal; and

feeding the compensated input signal to the backlash to produce a compensated output signal.

2. The method according to claim 1, further comprising:

amplifying the error signal prior to feeding it to the input signal.

3. The method according to claim 1, further comprising:

filtering the error signal through a low pass filter prior to feeding it to the input signal.

4. The method according to claim 1, further comprising:

measuring the output signal.

5. The method according to claim 1, wherein:

estimating the output signal y from the backlash by means of a software model.

6. A control system for compensating for backlash, the system being provided with an input signal and arranged to produce an output signal, said control system comprising:

means for creating an error signal by means of comparing the input signal and the output signal,

means for feeding the error signal to the input signal, and

means for feeding the compensated input signal to the backlash to produce a compensated output signal.

7. The control system according to claim 6, further comprising:

amplifying means arranged to amplify the error signal prior to feeding it to the input signal.

8. The control system according to claim 6, further comprising:

a low pass filter arranged to filter the error signal prior to feeding it to the input signal.

9. The control system according to claim 6, wherein the low pass filter has the transfer function (G(s)) according to:

10. The control system according to claim 6, further comprising:

means for measuring the output signal.

11. The control system according to claim 6, further comprising:

a software model arranged to estimate the output signal.

12. A computer program product, comprising:

a computer readable medium; and

computer program instructions recorded on the computer readable medium and executable by a processor for performing a method comprising providing an input signal to a control system the system producing an output signal, creating an error signal from a comparison between the input signal and the output signal, feeding the error signal to the input signal to produce a compensated input signal, and feeding the compensated input signal to the backlash to produce a compensated output signal.

13. (canceled)

14. (canceled)