Stepping motor control
AssigneeWisconsin Alumni Research Foundation
InventorMurray A. Thompson
Life of this patent
Estimating the term…
Abstract
A stepping motor control and driving circuit is provided to control stepping motors used to move a manipulator robot. The stepping motor control receives digital desired velocity and acceleration data from a controller computer and uses those instructions to generate and maintain appropriate control signals. The drive circuit, operating in response to the control signal, uses a summing amplifier responsive to output voltage and current to control the output impedance of the circuit.
Claims19
A stepping motor control circuit for operating a stepping motor under the control of a digital computer, the stepping motor having at all times a current velocity and a current position, the circuit comprising
- an input latch connected to receive two input values from the computer, one input value being desired velocity and the other input value being rate of change of velocity;
- a velocity register holding a value corresponding to the current velocity of the stepping motor;
- an adder to add the value of the rate of change of velocity to the value in the velocity register;
- a position register holding a value corresponding to the current position of the stepping motor;
- an adder to add the value of the current velocity to the value in the position register;
- a digital-to-analog converter to convert the value in the position register to an analog voltage for the motor;
- and
- a drive circuit connected to the output of the digital-to-analog converter to receive the analog output thereof and amplify it to drive the stepping motor.
A stepping motor drive circuit to operate a stepping motor with energy from a power supply comprising
- an input amplifier connected to present a selected input impedance to the motor;
- a summing feedback amplifier connected to receive feedback proportional to the voltage and current values applied to the motor to generate a chopping signal;
- a pair of upper and a pair of lower chopping circuits, the upper chopping circuits connected between the power supply and the motor, and the lower chopping circuits connected between the motor and ground, the chopping circuits connected to operate in response to the chopping signal so that only one upper chopping circuit and an opposite lower chopping circuit are operating at any one time.
Dependencies are inferred from the claim text.