Stepper motor control system
First Claim
Patent Images
1. A stepper motor control system for rotating a stepper motor by a desired amount of angular displacement, comprising:
- a stepper motor, having a rotatable member, for rotating the rotatable member at a rotation speed; and
control means, operatively connected to said stepper motor, for driving said stepper motor through the desired amount of angular displacement when the desired amount of angular displacement is larger than a predetermined amount by accelerating the rotatable member of said stepper motor by supplying an acceleration pulse sequence to said stepper motor until the rotation speed equals a predetermined rotation speed, driving the rotatable member at substantially the predetermined rotation speed, and sequentially decelerating the rotatable member of said stepper motor from the predetermined rotation speed by supplying a decelerating pulse sequence to said stepper motor to stop after the desired amount of angular displacement, and for driving said stepper motor when the desired amount of angular displacement is smaller than the predetermined amount of angular displacement by accelerating the rotatable member of said stepper motor by supplying the acceleration pulse sequence to said stepper motor until the rotation speed equals an intermediate rotation speed slower than the predetermined rotation speed determined according to the desired amount of angular displacement, regulating the rotation speed when the accelerating is stopped so that said stepper motor is able to follow decelerating control, and decelerating the rotatable member of said stepper motor by supplying a portion of the deceleration pulse sequence to said stepper motor after the regulating.
1 Assignment
0 Petitions
Accused Products
Abstract
A stepper motor control system for rotating a stepper motor by a desired amount of movement, including a first ROM (ROM3) for storing acceleration control data, a second ROM (ROM4) for storing deceleration control data and a change point control circuit for controlling a change point period between acceleration and deceleration. The change point control circuit assures that the acceleration is smoothly joined to the deceleration through the change point period so that the rotor of the stepper motor stops instantly and accurately at the target position.
18 Citations
29 Claims
-
1. A stepper motor control system for rotating a stepper motor by a desired amount of angular displacement, comprising:
-
a stepper motor, having a rotatable member, for rotating the rotatable member at a rotation speed; and control means, operatively connected to said stepper motor, for driving said stepper motor through the desired amount of angular displacement when the desired amount of angular displacement is larger than a predetermined amount by accelerating the rotatable member of said stepper motor by supplying an acceleration pulse sequence to said stepper motor until the rotation speed equals a predetermined rotation speed, driving the rotatable member at substantially the predetermined rotation speed, and sequentially decelerating the rotatable member of said stepper motor from the predetermined rotation speed by supplying a decelerating pulse sequence to said stepper motor to stop after the desired amount of angular displacement, and for driving said stepper motor when the desired amount of angular displacement is smaller than the predetermined amount of angular displacement by accelerating the rotatable member of said stepper motor by supplying the acceleration pulse sequence to said stepper motor until the rotation speed equals an intermediate rotation speed slower than the predetermined rotation speed determined according to the desired amount of angular displacement, regulating the rotation speed when the accelerating is stopped so that said stepper motor is able to follow decelerating control, and decelerating the rotatable member of said stepper motor by supplying a portion of the deceleration pulse sequence to said stepper motor after the regulating. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
-
-
19. A stepper motor control system for a stepper motor connectable to a load to be moved by a desired amount of angular displacement, said system comprising:
-
control means, operatively connected to the stepper motor, for controlling the angular displacement of the load including acceleration and deceleration; and storage means, operatively connected to said control means, for storing acceleration data, deceleration data and change point data which includes data necessary for a smooth transition from acceleration to deceleration and exact positioning of the load by the desired amount of angular displacement without oscillation of the load. - View Dependent Claims (20, 21, 22)
-
-
23. A method for controlling a stepper motor having a maximum velocity and a load to be moved a desired amount of angular displacement, comprising the steps of:
-
(a) accelerating the load of the stepper motor to a velocity slower than the maximum velocity; (b) decelerating the load of the stepper motor to a substantially instantaneous stop without oscillation after moving the desired distance; and (c) varying the velocity between said accelerating and decelerating steps to achieve a smooth transition between said accelerating and decelerating steps, resulting in the substantially instantaneous stop.
-
-
24. A method for controlling a stepper motor having a maximum velocity and a load to be moved a desired amount of angular displacement, the stepper motor having phases and the load being moved by energizing the phases of the stepper motor, said method comprising the steps of:
-
(a) accelerating the load of the stepper motor to a velocity slower than the maximum velocity; (b) decelerating the load of the stepper motor to a substantially instantaneous stop without oscillation after moving the desired distance; and (c) regulating the velocity between said accelerating and decelerating steps to achieve a smooth transition between said accelerating and decelerating steps, resulting in the substantially instantaneous stop, step (c) comprising the steps of; (ci) determining a first phase to be energized; (cii) determining a first amount of current to be supplied to the first phase; (ciii) determining the first amount of time to energize the first phase; and (civ) energizing the first phase by the first amount of current for the first amount of time to produce at least one of acceleration and deceleration of the load of the stepper motor. - View Dependent Claims (25, 26, 27, 28)
-
-
29. A method for controlling a stepper motor having a maximum velocity and a load to be moved a desired amount of angular displacement, comprising the steps of:
-
(a) accelerating the load of the stepper motor to a velocity slower than the maximum velocity; (b) decelerating the load of the stepper motor to a substantially instantaneous stop without oscillation after moving the desired distance, step (b) comprising the steps of; (bi) determining a first phase to be energized; (bii) determining a first amount of current to be supplied to the first phase; (biii) determining a first amount of time to energize the first phase; (biv) energizing the first phase by the first amount of current for the first amount of time to decelerate the load of the stepper motor; (bv) determining a second phase to be energized, which may be the first phase; (bvi) determining a second amount of current, smaller than the first amount of current, to be supplied to the second phase; (bvii) determining a second amount of time to energize the second phase; (bviii) energizing the second phase by the second amount of current for the second amount of time to decelerate the load of the stepper motor; and (bix) repeating steps (bv) through (bviii) as necessary to bring the load of the stepper motor to a stop without oscillation after the desired amount of angular displacement; and (c) regulating the velocity between said accelerating and decelerating steps to achieve a smooth transition between said accelerating and decelerating steps, resulting in the substantially instantaneous stop.
-
Specification