Dynamic pulse-width modulation motor control and medical device incorporating same
First Claim
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1. A system comprising:
- 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 to adjust a duty cycle for a modulated voltage applied to the motor in response to a difference between an expected displacement and the measured displacement, wherein;
the expected displacement is influenced by a commanded rotation of the rotor;
the sensor comprises an incremental position sensor to detect incremental rotations of the rotor;
the measured displacement comprises a measured number of the incremental rotations; and
the expected displacement comprises an expected number of the incremental rotations expected to be detected by the incremental position sensor in response to the commanded rotation.
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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
16 Claims
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1. A system comprising:
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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 to adjust a duty cycle for a modulated voltage applied to the motor in response to a difference between an expected displacement and the measured displacement, wherein; the expected displacement is influenced by a commanded rotation of the rotor; the sensor comprises an incremental position sensor to detect incremental rotations of the rotor; the measured displacement comprises a measured number of the incremental rotations; and the expected displacement comprises an expected number of the incremental rotations expected to be detected by the incremental position sensor in response to the commanded rotation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A system comprising:
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a motor having a rotor; a sensor to obtain a measured displacement that is influenced by rotation of the rotor; a pulse-width modulation module coupled to the motor, the pulse-width modulation module generating a pulse-width modulated voltage output that is applied to the motor; a motor driver module coupled between the pulse-width modulation module and the motor to apply the pulse-width modulated voltage output to the motor; and a control module coupled to the sensor to adjust a duty cycle for a modulated voltage applied to the motor in response to a difference between an expected displacement and the measured displacement, wherein; the expected displacement is influenced by a commanded rotation of the rotor; the control module adjusts the duty cycle of the pulse-width modulated voltage output generated by the pulse-width modulation module in response to the difference; and after adjusting the duty cycle, the control module operates the motor driver module to compensate for the difference between the expected displacement and the measured displacement while the motor driver module applies the pulse-width modulated voltage output having the adjusted duty cycle to the motor.
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11. A system comprising:
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a stepper motor having a rotor; an incremental position sensor to detect a first number of incremental rotations of the rotor per revolution of the rotor to obtain a measured displacement, the stepper motor having a second number of motor steps per revolution of the rotor; and a control module coupled to the incremental position sensor to; determines an expected displacement as an expected number of incremental rotations expected to be detected by the incremental position sensor in response to a commanded rotation based on a number of commanded motor steps and a relationship between the first number and the second number; and adjust a duty cycle for a modulated voltage applied to the stepper motor in response to a difference between the expected displacement and the measured displacement. - View Dependent Claims (12, 13, 14)
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15. A system comprising:
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a motor having a rotor; a pulse-width modulation module coupled to the motor to generate a pulse-width modulated voltage output having a duty cycle; a motor driver module coupled between the pulse-width modulation module and the motor to apply the pulse-width modulated voltage output to the motor; a sensor coupled to the motor to obtain a measured number of incremental rotations of the rotor; and a control module coupled to the pulse-width modulation module, the motor driver module, and the sensor to; operate the motor driver module to apply the pulse-width modulated voltage output to the motor to produce a commanded number of motor steps of rotation of the rotor; determine an expected number of incremental rotations; and adjust the duty cycle of the pulse-width modulated voltage output in response to a difference between the expected number and the measured number. - View Dependent Claims (16)
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Specification