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US 7,460,030 B2Granted
System and method for encoder failure detection
AssigneeContinental Automotive Systems US, Inc.
InventorsKenneth J. Farkas, Duo Deng
Life of this patent
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Abstract
An encoder failure detector system and method for detecting failure of an encoder during time periods when a zero rotational speed is expected. For example, in one embodiment a test signal is applied during a period when a zero rotational speed is expected and a failure is indicated if no movement of a rotor is detected in response to the test signal.
Claims33
A machine comprising:
- a rotatable component;
- and
- a control system, the control system comprising:
- an encoder configured to generate a signal in response to rotational movement of the rotatable component and coupled to the rotatable component;
- a torque and flux control configured to generate a control signal to control the rotatable component;
- and
- an encoder failure detector configured to:
- monitor the signal generated by the encoder;
- monitor the control signal;
- monitor a current;
- selectively apply a test signal when the monitoring satisfies a zero-speed test signal application criteria;
- and
- selectively generate an encoder failure signal based on a response to the application of the test signal.
10 more elements
A method of detecting a failure of an increment encoder in a machine, the method comprising:
- determining whether a zero-speed test signal application criteria is satisfied;
- and
- when the zero-speed test signal application criteria is satisfied:
- applying a test signal;
- measuring a response to the test signal, wherein measuring the response to the test signal comprises counting a number of pulses in an encoder channel output;
- and
- selectively generating a signal indicating an encoder failure based on the measured response to the test signal, wherein applying the test signal comprises applying a pulse to cause a magnitude of a current to move toward zero.
4 more elements
A method of detecting a failure of an increment encoder in a machine, the method comprising:
- determining whether a zero-speed test signal application criteria is satisfied;
- and
- when the zero-speed test signal application criteria is satisfied:
- applying a test signal;
- measuring a response to the test signal wherein measuring the response to the test signal comprises determining whether the zero-speed test signal application criteria remain satisfied during the application of the test signal;
- and
- selectively generating a signal indicating an encoder failure based on the measured response to the test signal and selectively generating the signal indicating an encoder failure comprises generating the signal indicating an encoder failure when it is determined that the zero-speed test signal application criteria remained satisfied during the application of the test signal.
4 more elements
A method of detecting a failure of an increment encoder in machine, the method comprising:
- determining whether a zero-speed test signal application criteria is satisfied;
- and
- when the zero-speed test signal application criteria is satisfied:
- applying a test signal wherein applying the test signal comprises applying a pulse to a control signal;
- measuring a response to the test signal;
- and
- selectively generating a signal indicating an encoder failure based on the measured response to the test signal.
4 more elements
A method of detecting a failure of an increment encoder in a machine, the method comprising:
- determining whether a zero-speed test signal application criteria is satisfied wherein determining whether the zero-speed test signal application criteria is satisfied comprises:
- determining whether a signal indicating movement of a rotatable component is received from the encoder during a threshold period of time;
- determining whether a magnitude of a current remains above a calibration value for the threshold period of time;
- and
- when the zero-speed test signal application criteria is satisfied:
- applying a test signal;
- measuring a response to the test signal, wherein measuring the response to the test signal comprises counting a number of pulses in an encoder channel output;
- and
- selectively generating a signal indicating an encoder failure based on the measured response to the test signal.
6 more elements
A method of detecting a failure of an increment encoder in a machine, the method comprising:
- determining whether a zero-speed test signal application criteria is satisfied:
- and
- when the zero-speed test signal application criteria is satisfied:
- applying a test signal;
- measuring a response to the test signal, wherein measuring the response to the test signal comprises counting a number of pulses in an encoder channel output;
- and
- selectively generating a signal indicating an encoder failure based on the measured response to the test signal, wherein selectively generating the signal indicating an encoder failure comprises generating the signal indicating an encoder failure when a signal indication movement of a rotatable component is not received from the encoder during application of the test signal.
4 more elements
A control system comprising:
- means for detecting movement of a rotatable component;
- means for controlling movement of the rotatable component;
- and
- means for detecting a failure of the means for detecting movement of the rotatable component, coupled to the means for detecting movement of the rotatable component and to the means for controlling movement of the rotatable component, wherein the means for detecting a failure of the means for detecting movement of the rotatable component selectively applies a test signal when a zero-speed test signal application criteria is satisfied;
- and selectively generates an encoder failure signal based on a response to the test signal.
2 more elements
A computer-readable medium storing instructions for causing a control system to facilitate detection of a failed increment encoder by performing a method comprising:
- determining whether a zero-speed test signal application criteria is satisfied:
- and
- when the zero-speed test signal application criteria is satisfied:
- applying a test signal:
- measuring a response to the test signal, wherein measuring the response to the test signal comprises counting a number of pulses in an encoder channel output;
- and
- selectively generating a signal indicating an encoder failure based on the measured response to the test signal.
4 more elements
A computer-readable medium storing instructions for causing a control system to facilitate detection of a failed increment encoder by performing a method comprising:
- determining whether a zero-speed test signal application criteria is satisfied;
- and
- when the zero-speed test signal application criteria is satisfied:
- applying a test signal:
- measuring a response to the test signal wherein measuring the response to the test signal comprises determining whether the zero-speed test signal application criteria remain satisfied during the application of the test signal;
- and
- selectively generating a signal indicating an encoder failure based on the measured response to the test signal and selectively generating the signal indicating an encoder failure comprises generating the signal indicating an encoder failure when it is determined that the zero-speed test signal application criteria remained satisfied during the application of the test signal.
4 more elements
A computer-readable medium storing instructions for causing a control system to facilitate detection of a failed increment encoder by performing a method comprising:
- determining whether a zero-speed test signal application criteria is satisfied;
- and
- when the zero-speed test signal application criteria is satisfied:
- applying a test signal wherein applying the test signal comprises applying a pulse to a control signal;
- measuring a response to the test signal;
- and
- selectively generating a signal indicating an encoder failure based on the measured response to the test signal.
4 more elements
A computer-readable medium storing instructions for causing a control system to facilitate detection of a failed increment encoder by performing a method comprising:
- determining whether a zero-speed test signal application criteria is satisfied;
- and
- when the zero-speed test signal application criteria is satisfied:
- applying a test signal wherein applying the test signal comprises applying a pulse to cause a magnitude of a current to move toward zero;
- measuring a response to the test signal;
- and
- selectively generating a signal indicating an encoder failure based on the measured response to the test signal.
4 more elements
A computer-readable medium storing instructions for causing a control system to facilitate detection of a failed increment encoder by performing a method comprising:
- determining whether a zero-speed test signal application criteria is satisfied wherein determining whether the zero-speed test signal application criteria is satisfied comprises:
- determining whether a signal indicating movement of a rotatable component is received from the encoder during a threshold period of time;
- determining whether a magnitude of a current remains above a calibration value for the threshold period of time;
- applying a first filter and a second filter to a control signal;
- and
- determining whether a difference between the first filtered control signal and the second filtered control signal remains below a threshold difference for the threshold period of time;
- and
- when the zero-speed test signal application criteria is satisfied:
- applying a test signal;
- measuring a response to the test signal;
- and
- selectively generating a signal indicating an encoder failure based on the measured response to the test signal.
9 more elements
A computer-readable medium storing instructions for causing a control system to facilitate detection of a failed increment encoder by performing a method comprising:
- determining whether a zero-speed test signal application criteria is satisfied;
- and
- when the zero-speed test signal application criteria is satisfied;
- applying a test signal;
- measuring a response to the test signal;
- and
- selectively generating a signal indicating an encoder failure based on the measured response to the test signal wherein selectively generating the signal indicating an encoder failure comprises generating the signal indicating an encoder failure when a signal indicating movement of a rotatable component is not received from the encoder during application of the test signal.
4 more elements
A computer-readable medium storing instructions for causing a control system to facilitate detection of a failed increment encoder by performing a method comprising:
- determining whether a zero-speed test signal application criteria is satisfied:
- and
- when the zero-speed test signal application criteria is satisfied:
- applying a test signal wherein the test signal is a pulse applied to a Q-axis voltage control signal;
- and
- measuring a response to the test signal;
- and
- selectively generating a signal indicating an encoder failure based on the measured response to the test signal.
5 more elements
Dependencies are inferred from the claim text.