Method and circuit arrangement for automatically parameterizing a quick-acting digital speed control loop

• US 6,274,995 B1
• Filed: 10/12/1999
• Issued: 08/14/2001
• Est. Priority Date: 10/09/1998
• Status: Expired due to Fees

• Current Assignee: E+E Eletronik Ges. M.B.H.
• Original Assignee: Dr. Johannes Heidenhain GmbH
• Inventors: Kerner, Norbert
• Primary Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US09/416,319
• Time in Patent Office: 672 Days
• Field of Search: 318/560-696, 364/148, 364/165, 364/724.19, 364/508, 364/192, 414/676, 356/358, 395/80, 901/45, 901/9
• US Class Current: 318/611
• CPC Class Codes: G05B 5/01 electric

Abstract

A filter module inserted into a speed control loop to shorten the rise time of the loop. The filter parameters of the filters provided in the filter module and the controller parameters are calculated in such a way that instances of resonant rise. The amplification factors for the proportional controller branch and the integral controller branch are increased, which leads to a shorter rise time.

Claims

1. A method for automatically parameterizing a quick-acting digital speed control loop in electro-drives of machine tools and robots that have a controller including branches with separately determined controller parameters and one or more filters, comprising:

determining an optimal value for at least one controller parameter associated with at least one branch of the controller with the aid of a specialized valuation function;

increasing the value of the controller parameter to produce vibrations in the control loop, the vibrations being associated with at least one resonant frequency;

determining at least one resonant frequency of the control loop;

calculating a damping factor for at least one filter, the damping factor being associated with the resonant frequency and equal to an actual rise time divided by the desired rise time; and

modifying the value of the controller parameter in accordance with the damping factor.

2. A method for automatically parameterizing a speed control loop in a controller having branches with different controller characteristics and one or more filters, comprising:

determining an optimal value for at least one controller parameter associated with at least one branch of the controller;

modifying the value of the controller parameter to produce vibrations in the control loop, the vibrations being associated with at least one resonant frequency;

determining at least one resonant frequency of the control loop;

determining at least one filter parameter associated with at least one of the filters, the filter parameter damping the resonant frequency in accordance with a desired rise time; and

modifying the value of the controller parameter in accordance with the filter parameter.

3. The method of claim 2, wherein said controller parameter is an amplification factor in a proportional branch of the controller.

4. The method of claim 3, wherein said modifying the value of the controller parameter further includes increasing the amplification factor.

5. The method of claim 2, wherein said determining at least one resonant frequency further includes:

determining a control loop feedback value over a specific time interval;

performing a Fourier transform on the control loop feedback value; and

obtaining a frequency spectrum associated with the Fourier transform.

6. The method of claim 5, further comprising:

determining a maximum amplitude of the frequency spectrum; and

determining the resonant frequency from the maximum amplitude.

7. The method of claim 2, wherein said determining at least one filter parameter further comprises determining the coefficients for a digital low-pass filter that damps frequencies above a predetermined frequency limit.

8. The method of claim 2, wherein said determining at least one filter parameter further comprises determining the coefficients for a digital notch filter that damps frequencies in a predetermined frequency band.

9. The method of claim 2, wherein said controller parameter is an amplification factor in an integral branch of the controller.

10. The method of claim 9, further comprising:

determining an actual rise time; and

calculating a damping factor for at least one filter, the damping factor being associated with the resonant frequency and equal to the actual rise time divided by a desired rise time.