Adaptive current control system for a stepper motor
View Patent ↗A method and a system are disclosed for adaptively controlling a stepper motor to produce a required torque output based on selection information provided by a sensor or a user/user interface which, in combination with a selector, selects a torque-related value. The selection information provided to the selector for selecting the stepper motor torque-related value may be, for example, the size or thickness of material being handled or the number of accumulated sheets for processing. The torque-related value is predetermined through experimentation and loaded into a lookup table stored in the memory of a motion control system board. The selected torque-related value is provided to a stepper motor driver which supplies the appropriate drive signal(s) to the stepper motor.
1. A stepper motor control system comprising:
a stepper motor;
a memory for storing a plurality of predetermined values indicative of desired stepper motor torque outputs;
a sensor for identifying a material;
a selector for selecting a desired stepper motor torque output by selecting one of said predetermined values; based upon the material sensed;
a motion control processor for supplying a stepper motor control signal as a function of at least the selected one of said predetermined values; and
a stepper motor drive circuit for driving the stepper motor in response to the stepper motor control signal.
2. The stepper motor control system of claim 1 further comprising a sensor, wherein the sensor issues the selection signal.
3. The stepper motor control system of claim 2 , wherein the predetermined values are stored in a lookup table.
4. The stepper motor control system of claim 2 , wherein the sensor is a feed tray sensor.
5. The stepper motor control system of claim 4 , wherein the feed tray sensor is at least one Hall-effect sensor.
6. The stepper motor control system of claim 1 , wherein the sensor signal is indicative of a thickness of a material.
7. The stepper motor control system of claim 1 , wherein the sensor signal is indicative of a set-up input.
8. The stepper motor control system of claim 1 , wherein the sensor signal is indicative of a type of material.
9. The stepper motor control system of claim 2 , wherein the sensor signal is indicative of a size of a material.
10. The stepper motor control system of claim 7 , further comprising:
a user interface for receiving the set-up input.
11. The stepper motor control system of claim 1 , wherein the predetermined values are control voltages.
12. The stepper motor control system of claim 1 , wherein the predetermined values are drive currents.
13. The stepper motor control system of claim 1 , wherein the predetermined values are torque values.
14. The stepper motor control system of claim 1 further comprising a data link, wherein the predetermined values are downloaded into the memory from the data link.
15. The stepper motor control system of claim 3 further comprising a data link, wherein the predetermined values are downloaded into the lookup table from the data link.
16. A method of controlling a stepper motor, comprising:
storing in a memory predetermined values indicative of desired stepper motor torque outputs;
sensing a material;
selecting a desired stepper motor torque output by selecting one of said predetermined values; based on the material sensed;
supplying a stepper motor control signal as a function of at least the selected one of said predetermined values; and
driving the stepper motor in response to the stepper motor control signal.
17. The method of controlling a stepper motor of claim 16 further comprising:
downloading the predetermined values into the memory from a data link.
18. The method of controlling a stepper motor of claim 16 further comprising:
formatting as a lookup table the predetermined values stored in the memory.
19. A stepper motor control system comprising:
storage means for storing predetermined values indicative of desired stepper motor torque outputs;
a sensor means for sensing material;
a selection means for selecting a desired stepper motor torque output by selecting one of said predetermined values; based upon the material sensed;
a motion control processor for supplying a stepper motor control signal as a function of at least the selected one of said predetermined values; and
a stepper motor driver for driving the stepper motor in response to the stepper motor control signal.
20. The stepper motor control system of claim 19 , wherein the storage means is a hardware memory selected from the group consisting of a memory device, a programmable logic circuit, a microprocessor, a microcontroller, an onboard cache, a RAM, a ROM, an EPROM, motion control processor, and a flash memory.
21. The stepper motor control system of claim 19 , wherein the storage means is a software program.
22. The stepper motor control system of claim 19 , wherein the selection means is a hardware device selected from the group consisting of a demultiplexer, a decoder, a programmable logic circuit, a processor, a central processor unit, an input/output interface, an input/output controller, a microprocessor, a microcontroller, a selector circuit, and a motion control processor.
23. The stepper motor control system of claim 19 , wherein the selection means is a software program.