Detection of the angular position of the rotor of a brush motor without using sensors
First Claim
1. A method of detecting an angular position of a rotor of a motor comprising:
- detecting at least one of switching ripple peaks and armature current disturbance peaks using a peak detector configured to generate a square wave having edges coinciding with detected peaks; and
filtering the square wave in a time domain by at leastgenerating an integration ramp, toward a set value, of an estimated ripple frequency for an interval of time based on the estimated ripple frequency,establishing an enablement range to reset the integration ramp by setting a threshold below and above the set value and a time window centered on an end time of each period of the estimated ripple frequency,resetting the integration ramp, and updating the estimated ripple frequency based upon a period determined by a time of the resetting, if an edge of the square wave is within the time window, to thereby validate the edge, andintegrating until the threshold is exceeded, resetting the integration ramp, and reducing the estimated ripple frequency to a period determined by the resetting, if the edge of the square wave is not within the time window.
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Abstract
A method of detecting an angular position of a rotor of a motor includes detecting switching ripple peaks and armature current disturbance peaks using a peak detector configured to generate a square wave having edges coinciding with detected peaks. The method further includes filtering the square wave in a time domain by generating an integration ramp, toward a set value, of an estimated ripple frequency for an interval of time based on the estimated ripple frequency. An enablement range is established to reset the integration ramp by setting a threshold below and above the set value and a time window centered on an end time of each period of the estimated ripple frequency. The method further includes resetting the integration ramp, and updating the estimated ripple frequency based upon a period determined by a time of the resetting, if an edge of the square wave is within the time window.
19 Citations
17 Claims
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1. A method of detecting an angular position of a rotor of a motor comprising:
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detecting at least one of switching ripple peaks and armature current disturbance peaks using a peak detector configured to generate a square wave having edges coinciding with detected peaks; and filtering the square wave in a time domain by at least generating an integration ramp, toward a set value, of an estimated ripple frequency for an interval of time based on the estimated ripple frequency, establishing an enablement range to reset the integration ramp by setting a threshold below and above the set value and a time window centered on an end time of each period of the estimated ripple frequency, resetting the integration ramp, and updating the estimated ripple frequency based upon a period determined by a time of the resetting, if an edge of the square wave is within the time window, to thereby validate the edge, and integrating until the threshold is exceeded, resetting the integration ramp, and reducing the estimated ripple frequency to a period determined by the resetting, if the edge of the square wave is not within the time window. - View Dependent Claims (2, 3, 4, 5, 7)
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6. A method of detecting an angular position of a rotor of a motor comprising:
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detecting at least one of switching ripple peaks and armature current disturbance peaks using a peak detector configured to generate a square wave having edges coinciding with detected peaks; and filtering the square wave in a time domain by at least generating an integration ramp, toward a set value, of an estimated ripple frequency for an interval of time based on the estimated ripple frequency, establishing an enablement range to reset the integration ramp by setting a threshold below and above the set value and a time window centered on an end time of each period of the estimated ripple frequency, resetting the integration ramp, and updating the estimated ripple frequency based upon a period determined by a time of the resetting, if an edge of the square wave is within the time window, to thereby validate the edge, integrating until the threshold is exceeded, resetting the integration ramp, and reducing the estimated ripple frequency to a period determined by the resetting, if the edge of the square wave is not within the time window, the integration being continued for detecting an eventual successive edge that is closer, when a first edge falls within a first semi-interval of the time window, to a terminal instant of the period of the estimated ripple frequency than a first validated edge, and resetting the integration ramp and updating the estimated ripple frequency, determining an angular position of the rotor between the switching ripple peaks and the armature current disturbance peaks at a stop of the motor by comparing a final amplitude reached by the integration ramp to an amplitude at the end of the period corresponding to the estimated ripple frequency.
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8. A system for controlling a motor based upon an angular position of a rotor of the motor, the system comprising:
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a processor configured for detecting at least one of switching ripple peaks and armature current disturbance peaks and generating a square wave having edges coinciding with detected peaks; the processor also configured for filtering the square wave in a time domain by at least generating an integration ramp, toward a set value, of an estimated ripple frequency for an interval of time based on the estimated ripple frequency, establishing an enablement range to reset the integration ramp by setting a threshold below and above the set value and a time window centered on an end time of each period of the estimated ripple frequency, resetting the integration ramp, and updating the estimated ripple frequency based upon a period determined by a time of the resetting, if an edge of the square wave is within the time window, to thereby validate the edge, and integrating until the threshold is exceeded, resetting the integration ramp, and reducing the estimated ripple frequency to a period determined by the resetting, if the edge of the square wave is not within the time window. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A system for controlling a motor based upon an angular position of a rotor of the motor, the motor being devoid of a position sensor, the system comprising:
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a sense element crossed by an armature current of the motor; an amplifier to amplify a current sense signal present across terminal nodes of the sense element; and a processor including a first analog-to-digital (AD) converter to receive the current sense signal and configured for detecting at least one of switching ripple peaks and armature current disturbance peaks and generating a square wave having edges coinciding with detected peaks based upon the current sense signal; the processor also configured for filtering the square wave in a time domain by at least generating an integration ramp, toward a set value, of an estimated ripple frequency for an interval of time based on the estimated ripple frequency, establishing an enablement range to reset the integration ramp by setting a threshold below and above the set value and a time window centered on an end time of each period of the estimated ripple frequency, resetting the integration ramp, and updating the estimated ripple frequency based upon a period determined by a time of the resetting, if an edge of the square wave is within the time window, to thereby validate the edge, and integrating until the threshold is exceeded, resetting the integration ramp, and reducing the estimated ripple frequency to a period determined by the resetting, if the edge of the square wave is not within the time window. - View Dependent Claims (16, 17)
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Specification