Drive performance measurement

Patent metadata

Field	Value
Publication number	US-9634600-B2
Application number	US-201414335589-A
Country	US
Kind code	B2
Filing date	Jul 18, 2014
Priority date	Jul 18, 2014
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

A motor drive is provided with integrated frequency response analysis tools for generating drive performance metrics that are independent of motion profile and tuning. The metrics are broadly applicable to a wide range of applications, tunings, and load types, and can be used to fairly compare performance across different drives models and assist in drive selection. The frequency analysis tools include a transformation algorithm that reduces or eliminates spectral leakages, a signal generation component that scales the test input signal as a function of frequency avoid saturation based on defined limits of the controlled system, and a phase unwrapping algorithm that correctly unwraps the phase of open-loop and closed-loop response curves. The frequency response analysis tools yield an open-loop response, a closed-loop response, a tracking error response, and a disturbance rejection response, which are used to derive performance metrics for the drive.

First claim

What is claimed is:

1. A motor drive, comprising:
a memory that stores computer-executable components;
a processor, operatively coupled to the memory, that executes the computer-executable components, the computer-executable components comprising:
an interface component configured to receive one or more configuration parameters, wherein the input parameters comprise at least a start frequency for a frequency analysis, a stop frequency for the frequency analysis, a number of frequency bins to be generated by the frequency analysis, and a type of spacing to be used to space the frequency bins;
a signal generator component configured to generate an input signal that controls a mechanical system during a frequency response test sequence; and
a performance metrics component configured to generate performance metric data for the motor drive based on the input signal and an output signal measured from the mechanical system representing a response of the mechanical system to the input signal,
wherein the performance metrics component is further configured to transform at least one of the input signal or the output signal from a time-domain signal to a frequency-domain signal based on the one or more input parameters, the frequency-domain signal comprises the number of frequency bins defined by the one or more input parameters, and the frequency bins are spaced between the start frequency and the stop frequency according to the type of spacing define by the one or more input parameters.

2. The motor drive of claim 1 , wherein the performance metric data comprises open-loop response data, closed-loop response data, tracking error response data, and disturbance rejection response data.

3. The motor drive of claim 2 , wherein the performance metrics component is further configured to unwrap a phase of frequency response curve data for a first frequency based on concurrent analysis of a first phase of the frequency response curve data at the first frequency and a second phase of the frequency response curve data at a second frequency that is previous to the first frequency.

4. The motor drive of claim 2 , wherein the frequency response test sequence is a closed-loop test, and the performance metric component is further configured to derive the open-loop response data from a result of the closed-loop test.

5. The motor drive of claim 2 , wherein the performance metrics component is further configured to convolute a plant identification response generated by the frequency response test sequence with a mathematical model of a controller to facilitate derivation of the open-loop response data, the closed-loop response data, the tracking error response data, and the disturbance rejection response data.

6. The motor drive of claim 1 , wherein the number of frequency bins is independent of a number of time samples of the time-domain signal.

7. The motor drive of claim 1 , wherein the frequency bins are unevenly spaced between the start frequency and the stop frequency.

8. The motor drive of claim 1 , wherein the frequency bins are evenly spaced between the start frequency and the stop frequency.

9. The motor drive of claim 1 , wherein the one or more input parameters further comprise at least defined operational limits of the mechanical system, wherein the defined operational limits comprise at least a travel limit, a velocity limit, a torque limit, a bias direction, and a bias amplitude.

10. The motor drive of claim 9 , wherein the input signal is a sinusoidal signal, and the signal generator component is further configured to scale an amplitude of the input signal as a function of a frequency of the input signal based on the defined operational limits.

11. The motor drive of claim 10 , wherein the signal generator component is configured to reduce the amplitude of the input signal as the frequency increases.

12. A method for deriving motor drive performance metrics, comprising:
receiving, by a motor drive comprising at least one processor, input parameters comprising at least a start frequency for a frequency analysis, a stop frequency for the frequency analysis, a number of frequency bins to be generated by the frequency analysis, and a type of spacing to be used to space the frequency bins;
generating, by the motor drive, an input signal that controls a mechanical system during execution of a frequency response test;
measuring an output signal from the mechanical system representing a response of the mechanical system to the input signal; and
deriving performance metric data for the motor drive based on the input signal and the output signal,
wherein the deriving comprises at least transforming at least one of the input signal or the output signal from a time-domain signal to a frequency-domain signal based on the input parameters, the frequency-domain signal comprises the number of frequency bins defined by the input parameters, and the frequency bins are spaced between the start frequency and the stop frequency according to the type of spacing define by the input parameters.

13. The method of claim 12 , wherein the deriving the performance metric data comprises deriving at least open-loop response data, closed-loop response data, tracking error response data, and disturbance rejection response data.

14. The method of claim 12 , wherein the transforming comprises generating the number of frequency bins independently of a number of time samples of the time-domain signal.

15. The method of claim 12 , wherein the transforming comprises one of spacing the frequency bins unevenly between the start frequency and the stop frequency or spacing the frequency bins evenly between the start frequency and the stop frequency.

16. The method of claim 12 , wherein the input signal is a sinusoidal signal, and the generating comprises scaling an amplitude of the sinusoidal signal as a function of a frequency of the sinusoidal signal based on at least one of a defined travel limit of the mechanical system, a defined velocity limit of the mechanical system, a defined torque limit of the mechanical system, a defined bias direction, or a defined bias amplitude.

17. The method of claim 16 , wherein the scaling comprising reducing the amplitude of the sinusoidal signal as the frequency increases.

18. The method of claim 12 , further comprising unwrapping a phase of frequency response curve data for a first frequency based on concurrent analysis of a first phase of the frequency response curve data at the first frequency and a second phase of the frequency response curve data at a second frequency that is previous to the first frequency.

19. A non-transitory computer-readable medium having stored thereon instructions that, in response to execution, cause a motor drive to perform operations, the operations comprising:
receiving frequency test parameters comprising at least a start frequency for a frequency analysis, a stop frequency for the frequency analysis, a number of frequency bins to be generated by the frequency analysis, and a type of spacing to be used to space the frequency bins;
generating an input signal configured to actuate a mechanical system during a frequency response test;
measuring a response of the mechanical system to the input signal to yield an output signal; and
generating performance metric data for the motor drive based on the input signal and the output signal,
wherein the generating comprises at least:
transforming at least one of the input signal or the output signal from a time-domain signal to a frequency-domain comprising the number of freq

Assignees

• Rockwell Automation Tech Inc

Inventors

• Miklosovic Robert
• Fast Brian
• Da Silva Aderiano

Classifications

• H02P23/14 Primary

  Estimation or adaptation of motor parameters, e.g. rotor time constant, flux, speed, current or voltage · CPC title

• H02P21/30

  Direct torque control [DTC] or field acceleration method [FAM] · CPC title

• G01R19/0092

  Measuring current only · CPC title

• G01R31/343

  in operation · CPC title

• H02P23/30

  Direct torque control [DTC] or field acceleration method [FAM] · CPC title