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US 12,613,112 B2Granted
Method and device for monitoring the track signals of a position change sensor
AssigneeSew-Eurodrive GmbH & Co. KG
InventorsMichael Müller, Florian Zerfass, Benjamin Norenburg, Christian Senft, Sebastian Richter
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Abstract
In a method and device for monitoring the track signals of a position change sensor, a resource-optimized diagnosis of errors of track signals of a position change sensor is performed.
Claims23
A device, comprising:
- a position change sensor including:
- a scale including alternating bright and dark spots;
- and
- a first optical sensor and a second optical sensor, the scale being movable relative to the first optical sensor and the second optical sensor, the first optical sensor and the second optical sensor adapted to optically scan the scale, the first optical sensor adapted to generate a first track signal in response to the optical scanning of the scale, the second optical sensor adapted to generate a second track signal in response to the optical scanning of the scale, the track signals being continuous, sinusoidal analog electrical signals and being 90° out of phase with respect to each other, the position change sensor adapted to measure changes in position or angle of the scale relative to the first optical sensor and the second optical sensor;
- a first evaluation unit;
- a further evaluation unit;
- and
- a logic operations unit;
- wherein the first evaluation unit is adapted to evaluate the track signals based on digital signal parameters;
- wherein the first evaluation unit is adapted to compute, and to make available at a first output of the first evaluation unit, a status information item from the digital signal parameters;
- wherein the first evaluation unit is adapted to generate an error signal at a further output of the first evaluation unit in response to detection of an error condition of the digital signal parameters;
- wherein the further evaluation unit is adapted to evaluate the track signals based on analog signal parameters;
- wherein the further evaluation unit is adapted to generate an error signal at an output of the further evaluation unit in response to departure from a valid range of the analog signal parameters;
- wherein the logic operations unit is adapted to generate, by performing a logic operation, a resulting error signal at an output of the logic operations unit as a function of the status information item, a state of the error signal of the first evaluation unit, and a state of the error signal of the further evaluation unit;
- and
- wherein the logic operations unit is adapted to transmit the resulting error signal to a first output of the device;
- wherein the first evaluation unit includes a Schmitt trigger unit, a quadrature decoder, an edge counter, a status information computation unit, and a comparator unit;
- wherein the Schmitt trigger unit is adapted to convert the track signals of the position change sensor to square-wave signals;
- wherein the quadrature decoder is adapted to generate a direction-dependent edge count value from the square-wave signals;
- wherein the edge counter is adapted to generate a direction-independent edge count value from the square-wave signals;
- the status information computation unit is adapted to compute a status information item from the direction-dependent edge count value and to make the status information item available at a first output of the first evaluation unit;
- and
- wherein the comparator unit is adapted to check, within a measuring cycle, a magnitude of change in the direction-dependent edge count value and a change in the direction-independent edge count value for equality and to set, in the event of inequality, an error signal at a further output of the first evaluation unit.
20 more elements
A device for diagnosing errors of track signals of a position change sensor and/or of an incremental encoder, comprising:
- a first evaluation unit;
- a further evaluation unit;
- and
- a logic operations unit;
- wherein the first evaluation unit is adapted to evaluate the track signals based on digital signal parameters;
- wherein the first evaluation unit is adapted to compute, and to make available at a first output of the first evaluation unit, a status information item from the digital signal parameters;
- wherein the first evaluation unit is adapted to generate an error signal at a further output of the first evaluation unit in response to detection of an error condition of the digital signal parameters;
- wherein the further evaluation unit is adapted to evaluate the track signals based on analog signal parameters;
- wherein the further evaluation unit is adapted to generate an error signal at an output of the further evaluation unit in response to departure from a valid range of the analog signal parameters;
- wherein the logic operations unit is adapted to generate, by performing a logic operation, a resulting error signal at an output of the logic operations unit as a function of the status information item, a state of the error signal of the first evaluation unit, and a state of the error signal of the further evaluation unit;
- wherein the logic operations unit is adapted to transmit the resulting error signal to a first output of the device;
- wherein the first evaluation unit includes a Schmitt trigger unit, a quadrature decoder, an edge counter, a status information computation unit, and a comparator unit;
- wherein the Schmitt trigger unit is adapted to convert the track signals of the position change sensor to square-wave signals;
- wherein the quadrature decoder is adapted to generate a direction-dependent edge count value from the square-wave signals;
- wherein the edge counter is adapted to generate a direction-independent edge count value from the square-wave signals;
- the status information computation unit is adapted to compute a status information item from the direction-dependent edge count value and to make the status information item available at a first output of the first evaluation unit;
- and
- wherein the comparator unit is adapted to check, within a measuring cycle, a magnitude of change in the direction-dependent edge count value and a change in the direction-independent edge count value for equality and to set, in the event of inequality, an error signal at a further output of the first evaluation unit.
15 more elements
A device for diagnosing errors of track signals of a position change sensor and/or of an incremental encoder, comprising:
- a first evaluation unit;
- a further evaluation unit;
- and
- a logic operations unit;
- wherein the first evaluation unit is adapted to evaluate the track signals based on digital signal parameters;
- wherein the first evaluation unit is adapted to compute, and to make available at a first output of the first evaluation unit, a status information item from the digital signal parameters;
- wherein the first evaluation unit is adapted to generate an error signal at a further output of the first evaluation unit in response to detection of an error condition of the digital signal parameters;
- wherein the further evaluation unit is adapted to evaluate the track signals based on analog signal parameters;
- wherein the further evaluation unit is adapted to generate an error signal at an output of the further evaluation unit in response to departure from a valid range of the analog signal parameters;
- wherein the logic operations unit is adapted to generate, by performing a logic operation, a resulting error signal at an output of the logic operations unit as a function of the status information item, a state of the error signal of the first evaluation unit, and a state of the error signal of the further evaluation unit;
- wherein the logic operations unit is adapted to transmit the resulting error signal to a first output of the device;
- wherein the further evaluation unit includes a timing generator unit, a lookup table unit, an analog-to-digital converter unit, and a trigonometric unit;
- wherein the timing generator unit is adapted to generate synchronization signals cyclically in variable intervals, as a function of data from a lookup table unit;
- wherein the analog-to-digital converter unit is adapted to convert a current analog level of the track signals of the position change sensor to corresponding digital pairs of values (UA, UB) as a function of the synchronization signal;
- and
- wherein the trigonometric unit is adapted to check the digital pairs of values of the track signals for validity, using the equation:
- U
- A
- 2
- +
- U
- B
- 2
- =
- (
- U
- ^
- A
- *
- sin
-
- (
- 2
-
- π
- *
- f
- *
- t
- )
- )
- 2
- +
- (
- U
- ^
- B
- *
- cos
-
- (
- 2
-
- π
- *
- f
- *
- t
- )
- )
- 2
- =
- R
- 2
- ,
- and, upon departure from a defined tolerance range of values, to set an error signal at an output of the further evaluation unit.
63 more elements
Dependencies are inferred from the claim text.