Dynamic command notch filter

Patent metadata

Field	Value
Publication number	US-12372951-B2
Application number	US-202218079282-A
Country	US
Kind code	B2
Filing date	Dec 12, 2022
Priority date	Dec 12, 2022
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

Abstract

A system and method for reducing mechanical oscillations in a multi-axis control system provides a first command for a dynamic notch filter at a first update rate to multiple motor drives. Each motor drive is operatively connected to a motor for an axis in the multi-axis control system. Each motor drive receives a second command for desired operation of the motor at a second update rate. Operation of the dynamic notch filter in each motor drive is changed as a function of the first command at the first update rate, and each motor drive generates a desired output voltage for desired operation of the motor at a third update rate. The third update rate is faster than the second update rate, the second command is passed through the dynamic notch filter to generate a filtered command, and the desired output voltage is generated as a function of the filtered command.

First claim

We claim:

1. A method for reducing mechanical oscillations in a multi-axis control system, the method comprising the steps of:
receiving at a plurality of motor drives a first command for a dynamic notch filter at a first update rate, wherein each of the plurality of motor drives is operatively connected to a motor for an axis in the multi-axis control system;
receiving at the plurality of motor drives a second command for desired operation of the motor at a second update rate;
changing operation of the dynamic notch filter in each of the plurality of motor drives as a function of the first command at the first update rate; and
generating a desired output voltage for desired operation of the motor from the motor drive at a third update rate, wherein:
the third update rate is faster than the second update rate,
the second command is passed through the dynamic notch filter to generate a filtered command, and
the desired output voltage is generated as a function of the filtered command.

2. The method of claim 1 wherein the first update rate is the same as the second update rate.

3. The method of claim 1 , wherein the first command is an enable command for the dynamic notch filter.

4. The method of claim 1 , wherein the first command is a desired frequency for the dynamic notch filter.

5. The method of claim 4 , wherein a controller operative to generate the first command includes a memory configured to store either an equation to determine the desired frequency or a lookup table containing a plurality of values for the desired frequency.

6. The method of claim 5 further comprising the steps of:
generating a frequency response in each of the plurality of motor drives, wherein the frequency response is generated as a function of the second command and of a position feedback signal corresponding to an angular position of the motor for the axis to which the motor drive is connected;
transmitting the frequency response from each of the plurality of motor drives to the controller; and
determining the equation or the lookup table in the controller as a function of the frequency response from each of the plurality of motor drives.

7. The method of claim 1 , wherein the first and second commands are received from a controller, the method further comprising the steps of:
transmitting from each of the plurality of motor drives to the controller a position feedback signal corresponding to an angular position of the motor for the axis to which the motor drive is connected; and
determining in the controller the first command as a function of the position feedback signal received from each of the plurality of motor drives.

8. The method of claim 1 , wherein:
the second command is a matrix defining desired operation of a link controlled by the axis in a plurality of dimensions, and
the dynamic notch filter includes a plurality of notch frequencies, wherein each of the plurality of notch frequencies corresponds to one of the plurality of dimensions.

9. The method of claim 1 , wherein:
the second command is a matrix defining desired operation of a link controlled by the axis in a plurality of dimensions, and
the dynamic notch filter includes a single frequency, corresponding to one of the plurality of dimensions.

10. The method of claim 1 , wherein the dynamic notch filter is a first dynamic notch filter, the method further comprising the steps of:
receiving at the plurality of motor drives a third command for a second dynamic notch filter at the first update rate; and
changing operation of the second dynamic notch filter in each of the plurality of motor drives as a function of the third command at the first update rate, wherein the second command is passed through the first dynamic notch filter and the second dynamic notch filter to generate the filtered command.

11. A system for reducing mechanical oscillations in a multi-axis control system, the system comprising:
an industrial controller operative to generate a first command at a first update rate and a second command at a second update rate, wherein the first command is for a dynamic notch filter and the second command is a desired motion of at least one motor; and
a plurality of motor drives in communication with the industrial controller, wherein each motor drive:
controls operation of at least one motor in the multi-axis control system,
receives the first command and the second command from the industrial controller,
changes operation of the dynamic notch filter as a function of the first command at the first update rate,
passes the second command through the dynamic notch filter to obtain a filtered command, and
generates an output voltage for desired operation of the at least one motor connected to the motor drive as a function of the filtered command.

12. The system of claim 11 , wherein the first update rate is the same as the second update rate.

13. The system of claim 11 , wherein the first command is an enable command for the dynamic notch filter.

14. The system of claim 11 , wherein the first command is a desired frequency for the dynamic notch filter.

15. The system of claim 11 , wherein:
the second command includes a plurality of motion commands,
each of the plurality of motion commands corresponds to one of the plurality of motor drives, and
the industrial controller transmits each of the plurality of motion commands to a corresponding motor drive at the second update rate.

16. The system of claim 15 , wherein each of the plurality of motor drives is further configured to:
generate a frequency response as a function of the second command and of a position feedback signal corresponding to an angular position of the at least one motor to which the motor drive is connected; and
transmit the frequency response from each of the plurality of motor drives to the industrial controller.

17. The system of claim 16 , wherein:
the industrial controller further includes a memory configured to store either an equation to determine the first command or a lookup table containing a plurality of values for the first command; and
the industrial controller is further configured to determine the equation or the plurality of values for the lookup table as a function of the frequency response from each of the plurality of motor drives.

18. The system of claim 11 , wherein:
each of the plurality of motor drives is further configured to:
receive a position feedback signal corresponding to an angular position of the at least one motor to which the motor drive is connected, and
transmit the position feedback signal to the industrial controller; and

the industrial controller is further operative to determine the first command as a function of the position feedback signal received from each of the plurality of motor drives.

19. A method for reducing mechanical oscillations in a multi-axis control system, the method comprising the steps of:
receiving at each of a plurality of motor drives a feedback signal corresponding to an angular position of a motor, wherein the motor is operatively connected to one of the plurality of motor drives and the feedback signal is provided to a corresponding motor drive to which the motor is operatively connected;
transmitting the angular position of the motor from each of the plurality of motor drives to an industrial controller;
generating at the industrial controller a first command for a dynamic notch filter at a first update rate;
generating at the industrial controller a second command for desired operation of the m

Assignees

• Rockwell Automation Tech Inc

Inventors

• Hoffman Jonathan D
• Gattani Vishesh

Classifications

• G05B19/41885

  characterised by modeling, simulation of the manufacturing system · CPC title

• G05B19/4183

  characterised by data acquisition, e.g. workpiece identification · CPC title

• G05B2219/41032

  Backlash · CPC title

• G05B2219/39176

  Compensation deflection arm · CPC title

• G05B2219/39186

  Flexible joint · CPC title