Dynamic pulse-width modulation motor control and medical device incorporating same
First Claim
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1. A method of controlling a motor, the method comprising:
- applying a modulated voltage to the motor to produce a commanded rotation of a rotor of the motor;
determining an expected displacement based on the commanded rotation;
obtaining a measured displacement influenced by rotation of the rotor in response to applying the modulated voltage to the motor to produce the commanded rotation; and
adjusting a duty cycle of the modulated voltage in response to a difference between the expected displacement and the measured displacement.
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Abstract
Apparatus are provided for motor control systems and related medical devices. In one embodiment, a control system includes a motor having a rotor, a sensor to obtain a measured displacement that is influenced by rotation of the rotor, and a control module coupled to the sensor. The control module adjusts a duty cycle for a modulated voltage applied to the motor in response to a difference between an expected displacement and the measured displacement. The expected displacement is influenced by or otherwise corresponds to a commanded rotation of the rotor.
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Citations
20 Claims
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1. A method of controlling a motor, the method comprising:
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applying a modulated voltage to the motor to produce a commanded rotation of a rotor of the motor; determining an expected displacement based on the commanded rotation; obtaining a measured displacement influenced by rotation of the rotor in response to applying the modulated voltage to the motor to produce the commanded rotation; and adjusting a duty cycle of the modulated voltage in response to a difference between the expected displacement and the measured displacement. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A method of controlling a motor, the method comprising:
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applying a modulated voltage to the motor to produce a commanded rotation of a rotor of the motor, the modulated voltage having a duty cycle, the modulated voltage oscillating between a first voltage and a second voltage, the modulated voltage being equal to the first voltage for a percentage of a time interval corresponding to the duty cycle; determining an expected displacement based on the commanded rotation; obtaining a measured displacement influenced by rotation of the rotor in response to applying the modulated voltage to the motor to produce the commanded rotation; and adjusting the duty cycle of the modulated voltage in response to a difference between the expected displacement and the measured displacement.
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20. A method of controlling a stepper motor, the method comprising:
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applying a modulated voltage to the stepper motor to produce a commanded number of motor steps of rotation of a rotor of the stepper motor, the modulated voltage having a duty cycle, the modulated voltage oscillating between a first voltage and a second voltage, the modulated voltage being equal to the first voltage for a percentage of a time interval corresponding to the duty cycle; determining an expected number of incremental rotations expected to be detected by a sensor coupled to the stepper motor in response to applying the modulated voltage to the stepper motor to produce the commanded number of motor steps based on the commanded number of motor steps; obtaining a measured number of incremental rotations of the rotor from the sensor in response to applying the modulated voltage to the stepper motor to produce the commanded number of motor steps; and adjusting the duty cycle of the modulated voltage in response to a difference between the expected number and the measured number.
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Specification