Vibration-Type Angular Rate Sensor

Patent metadata

Field	Value
Publication number	US-2016377433-A1
Application number	US-201515121426-A
Country	US
Kind code	A1
Filing date	Feb 12, 2015
Priority date	Feb 26, 2014
Publication date	Dec 29, 2016
Grant date	—

Abstract

This vibration-type angular rate sensor corrects a sensor output from a secondary-side control circuit by adding, to a closed control loop of the secondary-side control circuit, an offset value based on the output of a closed control loop of a primary-side control circuit dependent on temperature.

First claim

1 .- 8 . (canceled)

9 . A vibration-type angular rate sensor comprising:
a vibrator; a primary-side control circuit including a closed control loop, of which an output induces a primary vibration in the vibrator; and a secondary-side control circuit including a closed control loop that detects a secondary vibration generated in the vibrator due to an angular velocity applied to the vibrator, wherein a sensor output from the secondary-side control circuit inversely proportional to a second power of a temperature change of a gain of the vibrator is corrected by adding, to the closed control loop of the secondary-side control circuit, an offset value based on the output of the closed control loop of the primary-side control circuit inversely proportional to the temperature change of the gain of the vibrator.

10 . The vibration-type angular rate sensor according to claim 9 , wherein
the primary-side control circuit and the secondary-side control circuit include a primary-side loop filter and a secondary-side loop filter in the closed control loops, respectively, and the sensor output is corrected by adding, to an input of the secondary-side loop filter, the offset value based on an output of the primary-side loop filter inversely proportional to the temperature change of the gain of the vibrator.

11 . The vibration-type angular rate sensor according to claim 9 , wherein
when the sensor output is corrected in an analog manner, the sensor output is corrected by adding, to the closed control loop of the secondary-side control circuit, a first offset value based on the output of the primary-side control circuit inversely proportional to the temperature change of the gain of the vibrator to correct the sensor output inversely proportional to the second power of the temperature change of the gain of the vibrator from the secondary-side control circuit and a second offset value based on a constant signal not dependent on temperature to correct the sensor output inversely proportional to the temperature change of the gain of the vibrator from the secondary-side control circuit, and adjusting addition amounts of the first offset value d the second offset value.

12 . The vibration-type angular rate sensor according to claim 11 , wherein
the primary-side control circuit and the secondary-side control circuit include a primary-side loop filter and a secondary-side loop filter in the closed control loops, respectively, and the sensor output is corrected in an analog manner by adding, to an input of the secondary-side loop filter, the first offset value based on an output of the primary-side loop filter inversely proportional to the temperature change of the in of the vibrator and the second offset value based on the constant signal not dependent on temperature, and adjusting the addition amounts of the first offset value and the second offset value.

13 . The vibration-type angular rate sensor according to claim 12 , wherein
a total V Out _ Total _ Error of an error in the sensor output caused in the closed control loop of the secondary-side control circuit by an error signal generated from a circuit block constituting the secondary-side control circuit and an error in the sensor output caused in the closed control loop of the secondary-side control circuit by cross talk from the primary-side control circuit to the secondary-side control circuit is expressed by a following expression (1) when a gain of the vibrator dependent on temperature is assumed as G R (T), and A, B, and C are assumed as constant values not dependent on temperature, and the sensor output is corrected in an analog manner by adjusting the addition amount of the first offset value based on the output of the primary-side control circuit inversely proportional to the temperature change of the gain of the vibrator to reduce A/G R 2 (T), which is a first term in the expression (1), to zero or substantially zero, and adjusting the addition amount of the second offset value based on the constant signal not dependent on temperature to reduce B/G R (T), which is a second term in the expression (1), to zero or substantially zero.

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14 . The vibration-type angular rate sensor according to claim 9 , wherein
when the sensor output is corrected in a digital manner, the sensor output is corrected by quantizing the output of the primary-side control circuit inversely proportional to the temperature change of the gain of the vibrator, and adding, to the secondary-side control circuit, the offset value for reducing an error in the sensor output caused by a temperature change to zero or substantially zero according to the quantized output of the primary-side control circuit.

Assignees

• Sumitomo Precision Prod Co

Inventors

• Moriguchi Takafumi

Classifications

• G01C19/5677 Primary

  of essentially two-dimensional [2D] vibrators, e.g. ring-shaped vibrators · CPC title