Method and circuitry for producing nominal position values for a closed loop position control of a numerically continuous-path controlled machine

• US 6,774,598 B1
• Filed: 06/26/2002
• Issued: 08/10/2004
• Est. Priority Date: 09/08/1999
• Status: Expired due to Term

• Current Assignee: Dr. Johannes Heidenhain GmbH
• Original Assignee: Dr. Johannes Heidenhain GmbH
• Inventors: Fauser, Matthias, Kohler, Frieder
• Primary Examiner(s): Leykin, Rita
• Application Number:
  US10/070,907
• Time in Patent Office: 776 Days
• Field of Search: 318/600, 318/615, 318/571, 318/561, 700/28, 700/33, 700/80
• US Class Current: 318/600
• CPC Class Codes: G05B 19/41 characterised by interpolation, e.g. the computation of intermediate points between programmed end points to define the path to be followed and the rate of travel along that path G05B19/25, G05B19/31, G05B19/37, G05B19/39, G05B19/40 take precedence
• CPC Class Codes: G05B 19/4103 Digital interpolation
• CPC Class Codes: G05B 2219/34119 Function generator, filter after interpolator to control position error
• CPC Class Codes: G05B 2219/34167 Coarse fine, macro microinterpolation, preprocessor
• CPC Class Codes: G05B 2219/41117 Cancel vibration during positioning of slide
• CPC Class Codes: G05B 2219/41151 Finite impulse response filter

Abstract

A method for generating nominal position values for a position control loop of a numerically continuous-path controlled machine. The method includes presetting nominal position values with a defined interpolator clock rate, digitally filtering the preset nominal position values and transmitting the digitally filtered nominal position values to a position control loop, which with them controls motion of a machine on a path curve at a defined position control clock rate. Adjusting the digitally filtering nominal position values as a function of dynamic characteristics of the machine and adjusting an interpolator clock rate as a function of the dynamic characteristics of the machine.

Claims

1. A method for generating nominal position values for a position control loop of a numerically continuous-path controlled machine, comprising:

presetting nominal position values with a defined interpolator clock rate;

digitally filtering said preset nominal position values; and

transmitting said digitally filtered nominal position values to a position control loop, which with them controls motion of a machine on a path curve at a defined position control clock rate;

adjusting said digitally filtering nominal position values as a function of dynamic characteristics of said machine; and

adjusting an interpolator clock rate as a function of said dynamic characteristics of said machine.

2. The method of claim 1, wherein said dynamic characteristic of said machine comprises a lowest resonant frequency of said machine.

3. The method of claim 1, wherein said adjusting of said interpolator clock rate is based in part on a position control clock rate, and said interpolator clock rate is selected as an integral fraction of said position control clock rate.

4. The method of claim 1, further comprising fine interpolating said digitally filtered preset nominal position values before said transmission to a position control loop.

5. The method of claim 4, further comprising transmitting said fine interpolated digital filtered nominal position values to said position control loop at said position control clock rate.

6. The method of claim 2, further comprising calculating a filter set with filter coefficients for a defined resonant frequency and a set interpolator clock rate.

7. The method of claim 2, further comprising storing a filter set with filter coefficients for a defined resonant frequency and a set interpolator clock rate.

8. A circuit arrangement for generating nominal position values for a position control loop of a numerically continuous-path controlled machine, comprising:

an interpolator unit for presetting nominal position values with a defined interpolator clock rate;

a nominal position value filter for digital filtration of said nominal position values preset by said interpolator unit;

a position control loop, which processes said digitally filtered nominal position values in such a way that by way of them a motion of a machine on a path curve is controllable at a defined position control clock rate, wherein along with said nominal position value filter, said interpolator clock rate is also adjusted as a function of dynamic characteristics of said machine.

9. The circuit arrangement of claim 8, wherein said nominal position value filter comprises a FIR filter, by way of which a low pass filtration results.

10. The circuit arrangement of claim 8, wherein said nominal position value filter comprises a memory unit, in which different filter coefficient sets for different machine resonant frequencies are stored in said memory unit, which each serve as a dynamic characteristic for setting said interpolator clock rate.

11. The circuit arrangement of claim 8, wherein said nominal position value filter comprises a calculation unit for calculating filter coefficient sets for an applicable resonant frequency of said machine, which serves as a dynamic characteristic for setting said interpolator clock rate.

12. The circuit arrangement of claim 8, further comprising a fine interpolator disposed between said nominal position value filter and said position control loop, wherein said fine interpolator performs a fine interpolation of said nominal position values.

13. The circuit arrangement of claim 12, wherein said fine interpolator transmits nominal position values at said position control clock rate to said position control loop.