Apparatus and method for setting a gyroscope zero point
First Claim
1. An apparatus for setting a gyroscope zero point reference value, comprising:
- a gyroscope for outputting a signal indicating angular velocity in the form of a voltage;
a global positioning system (GPS) receiver for receiving a GPS signal;
an analog-to-digital (A/D) converter for digitizing the voltage output from the gyroscope; and
a controller for detecting a speed and a direction angle of a vehicle from the received GPS signal, determining if the vehicle is traveling in a straight line, and filtering the voltage output from the gyroscope to obtain a gyroscope zero point reference value if the vehicle is traveling in the straight line,wherein the gyroscope zero point reference value is computed by ZPT_Ref=(N−
1)/N*ZPT_Ref+1/N*Mean(Y[0 . . . 9]), where ZPT_Ref denotes a gyroscope zero point reference value, N denotes a smoothing filter constant, and Mean(Y[0 . . . 9]) denotes a mean value of Y[0] to Y[9] values, each of the Y[0] to Y[9] values being an average of an accumulated value obtained by accumulating a mean value of gyroscope output values measured in a predetermined cycle a predetermined number of times.
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Accused Products
Abstract
Disclosed are an apparatus and a method for computing a position of a moving entity, and an apparatus and method for setting a gyroscope zero point or a gyroscope zero point reference value. In the apparatus for setting the gyroscope zero point, a gyroscope outputs a signal of angular velocity in the form of voltage. A global positioning system (GPS) receiver receives a GPS signal. An analog-to-digital (A/D) converter digitizes the voltage output from the gyroscope. A controller detects a speed and a direction angle of a vehicle from the received GPS signal, determines if the vehicle is traveling in a straight line, and filters the voltage output from the gyroscope to obtain a gyroscope zero point reference value if the vehicle is traveling in the straight line.
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Citations
5 Claims
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1. An apparatus for setting a gyroscope zero point reference value, comprising:
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a gyroscope for outputting a signal indicating angular velocity in the form of a voltage; a global positioning system (GPS) receiver for receiving a GPS signal; an analog-to-digital (A/D) converter for digitizing the voltage output from the gyroscope; and a controller for detecting a speed and a direction angle of a vehicle from the received GPS signal, determining if the vehicle is traveling in a straight line, and filtering the voltage output from the gyroscope to obtain a gyroscope zero point reference value if the vehicle is traveling in the straight line, wherein the gyroscope zero point reference value is computed by ZPT_Ref=(N−
1)/N*ZPT_Ref+1/N*Mean(Y[0 . . . 9]), where ZPT_Ref denotes a gyroscope zero point reference value, N denotes a smoothing filter constant, and Mean(Y[0 . . . 9]) denotes a mean value of Y[0] to Y[9] values, each of the Y[0] to Y[9] values being an average of an accumulated value obtained by accumulating a mean value of gyroscope output values measured in a predetermined cycle a predetermined number of times. - View Dependent Claims (2)
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3. A method for setting a gyroscope zero point reference value, comprising:
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checking global positioning system (GPS) measurement in a predetermined cycle; determining if a vehicle is traveling in a straight line from a result of the GPS measurement, incrementing a count value associated with the straight-line traveling if the vehicle is traveling in the straight line, and computing a gyroscope zero point reference value according to ZPT_Ref=(N−
1)/N*ZPT_Ref+1/N*Mean(Y[0 . . . 9]) where ZPT_Ref denotes a gyroscope zero point reference value, N denotes a smoothing filter constant, and Mean(Y[0 . . . 9]) is a mean value of Y[0] to Y[9] values, each of the Y[0] to Y[9] values being an average of an accumulated value obtained by accumulating a mean value of gyroscope output values measured in a predetermined cycle a predetermined number of times; anddetermining the count value associated with the straight-line traveling after computing the gyroscope zero point reference value, storing the computed gyroscope zero point reference value in a memory if the count value is larger than N, and waiting for the cycle to be reached if the count value is less than or equal to N.
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4. An apparatus for setting a gyroscope zero point, comprising:
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a gyroscope for outputting a signal indicating angular velocity in the form of a voltage; a global positioning system (GPS) receiver for receiving a GPS signal; an analog-to-digital (A/D) converter for digitizing the voltage output from the gyroscope; and a controller for analyzing the GPS signal, determining if a vehicle is traveling in a straight line, obtaining a gyroscope zero point reference value, comparing a gyroscope output range value with a noise level value in a predetermined cycle, and updating a gyroscope zero point when the gyroscope output range value is less than or equal to the noise level value, wherein the gyroscope output range value is computed by Range=MAX(Y[0 . . . 9])−
MIN(Y[0 . . . 9]), where MAX(Y[0 . . . ]) is a maximum value of Y[0] to Y[9] values, and MIN(Y[0 . . . 9]) is a minimum value of the Y[0] to Y[9] values, each of the Y[0] to Y[9] values being an average of an accumulated value obtained by accumulating a mean value of gyroscope output values measured in a predetermined cycle the predetermined number of times, andwherein the noise level value is updated to a minimum value of computed gyroscope output range values whenever the gyroscope output range value is less than or equal to the noise level value. - View Dependent Claims (5)
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Specification