Stepper trajectory driver with numerical controlled oscillators operated at frequency provided by a synchronized clock signal

Patent metadata

Field	Value
Publication number	US-10103659-B2
Application number	US-201615370971-A
Country	US
Kind code	B2
Filing date	Dec 6, 2016
Priority date	Dec 7, 2015
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

A stepper control circuit includes numerical controlled oscillators configured to provide step signals for multiple axes of stepper motor movement. The numerical controlled oscillators are configured to be operated at a same frequency provided by a synchronized clock signal.

First claim

The invention claimed is:

1. A stepper motor control circuit comprising:
a first numerical controlled oscillator configured to provide step signals for a first axis of stepper motor movement;
a second numerical controlled oscillator configured to provide step signals for a second axis of stepper motor movement; and
a prescaler oscillator configured to offset operation of the first numerical controlled oscillator by one half of a remainder difference of a divisor, the divisor including a ratio between a first count of steps to be performed by the first numerical controlled oscillator and a second count of steps to be performed by the second numerical controlled oscillator;

wherein the first and second numerical controlled oscillators are configured to be operated at a same frequency provided by a synchronized clock signal.

2. The stepper motor control circuit of claim 1 , further comprising a first counter configured to receive control signals for the first axis of stepper motor movement and a second counter configured to receive control signals for the second axis of stepper motor movement.

3. The stepper motor control circuit of claim 1 , wherein the prescaler oscillator is further configured to set the same frequency of the first and second numerical controlled oscillators.

4. The stepper motor control circuit of claim 1 , wherein the prescaler oscillator is further configured to set a first constant value of the first numerical controlled oscillator, the first constant value configured to set a rate of pulse generation of the first numerical controlled oscillator.

5. The stepper motor control circuit of claim 1 , wherein the prescaler oscillator is further configured to set a first constant value of the first numerical controlled oscillator, the first numerical controlled oscillator configured to repeatedly add the first constant value to a counter to set a rate of pulse generation of the first numerical controlled oscillator.

6. The stepper motor control circuit of claim 1 , wherein the prescaler oscillator is further configured to set a first constant value of the first numerical controlled oscillator, the first numerical controlled oscillator configured to repeatedly add the first constant value to a counter and generate a motor pulse upon overflow of the counter to set a rate of pulse generation of the first numerical controlled oscillator.

7. The stepper motor control circuit of claim 1 , wherein the prescaler oscillator is further configured to accelerate movement of a motor by increasing frequency of operation of the first and second numerical controlled oscillators simultaneously.

8. The stepper motor control circuit of claim 1 , further comprising a third numerical controlled oscillator configured to provide step signals for a third axis of stepper motor movement, wherein the first, second, and third numerical controlled oscillators are configured to be operated at the same frequency.

9. A method for controlling a stepper motor, comprising: providing step signals for a first axis of stepper motor movement by a first numerical controlled oscillator; providing step signals for a second axis of stepper motor movement by a second numerical controlled oscillator; and
offsetting operation of the first numerical controlled oscillator by one half of a remainder of a difference of a divisor, the divisor including ratio between a first count of steps to be performed by the first numerical controlled oscillator and a second count of steps to be performed by the second numerical controlled oscillator;

wherein control of the first and second numerical controlled oscillators is performed at a same frequency by a synchronized clock signal.

10. The method of claim 9 , further comprising receiving control signals for the first axis of stepper motor movement and control signals for the second axis of stepper motor movement into respective counters.

11. The method of claim 9 , further setting the same frequency of the first and second numerical controlled oscillators.

12. The method of claim 9 , further comprising setting a first constant value of the first numerical controlled oscillator, the first constant value configured to set a rate of pulse generation of the first numerical controlled oscillator.

13. The method of claim 9 , further comprising setting a first constant value of the first numerical controlled oscillator, the first numerical controlled oscillator configured to repeatedly add the first constant value to a counter to set a rate of pulse generation of the first numerical controlled oscillator.

14. The method of claim 9 , further comprising setting a first constant value of the first numerical controlled oscillator, the first numerical controlled oscillator configured to repeatedly add the first constant value to a counter and generate a motor pulse upon an overflow of the counter to set a rate of pulse generation of the first numerical controlled oscillator.

15. The method of claim 9 , further comprising accelerating movement of a motor by increasing frequency of operation of the first and second numerical controlled oscillators simultaneously.

16. The method of claim 9 , further comprising providing step signals for a third axis of stepper motor movement by a third numerical controlled oscillator, wherein the first, second, and third numerical controlled oscillators are operated at the same frequency.

Assignees

• Microchip Tech Inc

Inventors

• Curtis Keith

Classifications

• G05B19/40

  Open loop systems, e.g. using stepping motor · CPC title

• H02P8/14 Primary

  Arrangements for controlling speed or speed and torque (H02P8/12, H02P8/22 take precedence) · CPC title

• H02P8/40

  Special adaptations for controlling two or more stepping motors · CPC title

• G05B2219/42181

  Rom contains sin and cos table to drive step motor · CPC title

• H02P8/34

  Monitoring operation (H02P8/36 takes precedence) · CPC title