POSITIONING APPARATUS COMPRISING AN INERTIAL SENSOR AND INERTIAL SENSOR TEMPERATURE COMPENSATION METHOD

• US 20150276783A1
• Filed: 03/12/2015
• Published: 10/01/2015
• Est. Priority Date: 03/31/2014
• Status: Active Grant

• Current Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Palella, Nicola Matteo, Colombo, Leonardo
• Granted Patent: US 10,317,421 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 19/5621 the devices involving a micromechanical structure
• CPC Class Codes: G01C 19/5656 the devices involving a micromechanical structure
• CPC Class Codes: G01C 19/5684 the devices involving a micromechanical structure
• CPC Class Codes: G01C 19/5712 the devices involving a micromechanical structure
• CPC Class Codes: G01C 21/1654 with electromagnetic compass
• CPC Class Codes: G01C 25/00 Manufacturing, calibrating, cleaning, or repairing instruments or devices referred to in the other groups of this subclass testing, calibrating or compensating compasses G01C17/38
• CPC Class Codes: G01P 1/006 used for thermal compensation
• CPC Class Codes: G01P 15/14 by making use of gyroscopes gyroscopes per se G01C19/00
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled
• CPC Class Codes: G01S 5/018 Involving non-radio wave signals or measurements

Abstract

A positioning apparatus includes: a reference device configured to provide a measured current motion angle of a vehicle; an inertial sensor configured to provide a current input angular rate of the vehicle and associated with at least one inertial sensor behavior parameter dependent on inertial sensor temperature; a temperature sensor configured to provide an input temperature variation of the inertial sensor on a time interval; and a digital estimator configured to recursively computing an estimated current motion angle of the vehicle and at least one previously estimated inertial sensor behavior parameter as function of: the measured current motion angle, a previously estimated motion angle, the current input angular rate, and the input temperature variation.

Claims

1. An apparatus, comprising:

an inertial sensor configured to output a current angular rate and associated with at least one inertial sensor behavior parameter dependent on inertial sensor temperature;

a temperature sensor configured to output an indication of a time derivative of a temperature of the inertial sensor; and

position-estimation circuitry configured to recursively compute an estimated current motion angle of a vehicle and at least one estimated inertial sensor behavior parameter as function of;

an indication of a measured current motion angle;

a previously estimated motion angle;

the current angular rate; and

the indication of the time derivative of the temperature.

2. The apparatus according to claim 1 wherein the at least one inertial sensor behavior parameter comprises at least one of the following parameters:

inertial sensor sensitivity; and

inertial sensor zero-rate level.

3. The apparatus according to claim 1 wherein the measured current motion angle comprises one of:

a heading angle;

a pitch angle;

a roll angle; and

a linear combination of at least two of said heading angle, pitch angle and roll angle.

4. The apparatus according to claim 1 wherein the inertial sensor comprises a gyroscope.

5. The apparatus according to claim 4 wherein the inertial sensor includes a MEMs gyroscope structured to provide the current angular rate.

6. The apparatus according to claim 1 wherein the indication of the measured current motion angle is based on a Global Navigation Satellite System (GNSS) receiver output signal.

7. The apparatus according to claim 1 wherein the indication of the measured current motion angle is based on a magnetometer sensor output signal.

8. The apparatus according to claim 1 wherein the position-estimation circuitry comprises at least one of:

a Least Square Estimator (LSE) filter;

a Kalman filter;

an extended Kalman filter; and

a particle filter.

9. The apparatus according to claim 1 wherein the position estimation circuitry comprises an extended Kalman filter including:

an update section having a differential node module configured to receive the indication of the measured current motion angle, a Kalman gain matrix module and a measurement transformation module; and

a prediction section having a sum node, a delay module, a dynamic matrix module and output configured to provide the estimated current motion angle.

10. The apparatus according to claim 9 wherein:

the Kalman gain matrix module receives a measurement noise indicator;

the position-estimation circuitry comprises a measurement noise module associated with a Global Navigation Satellite System (GNSS) receiver and configured to compute said measurement noise indicator as a weighted combination of;

a signal strength computed from GNSS visible satellite signal power;

a Root-mean-square of pseudorange errors;

a Root-mean-square of Doppler errors;

a number of tracked satellites;

a Standard Deviation of vehicle position values; and

vehicle velocity values received from the GNSS receiver.

11. The apparatus according to claim 9 wherein the position-estimation circuitry is configured to compute a covariance matrix including a system noise matrix and to compute elements of the system noise matrix as function of measured vehicle dynamic quantities.

12. The apparatus according to claim 11 wherein the position-estimation circuitry is configured to compute said elements as function of parameters provided by a Global Navigation Satellite System (GNSS) receiver.

13. The apparatus according to claim 1 wherein the position-estimation circuitry is configured as to generate position information based on Global Navigation Satellite System (GNSS) signals and dead-reckoning positioning system signals.

14. The apparatus according to claim 1, comprising circuitry configured to provide at least one of:

Automatic Driver Assistance;

Vehicle to Vehicle Communications; and

Autonomous Pilot and Telematics services.

15. A system, comprising:

motion angle measurement circuitry configured to generate at least one indication of a measured current motion angle;

an inertial sensor configured to output a current angular rate and associated with at least one inertial sensor behavior parameter dependent on inertial sensor temperature;

a temperature sensor configured to output a time derivative of a temperature of the inertial sensor; and

position-estimation circuitry configured to recursively compute an estimated current motion angle of a vehicle and at least one estimated inertial sensor behavior parameter as function of;

the at least one indication of a measured current motion angle;

a previously estimated motion angle;

the current angular rate; and

the time derivative of the temperature.

16. The system according to claim 15 wherein the measured current motion angle comprises at least one of:

a heading angle;

a pitch angle;

a roll angle; and

a linear combination of at least two of said heading angle, pitch angle and roll angle.

17. The system according to claim 15 wherein the inertial sensor comprises a MEMs gyroscope.

18. The system of claim 15 wherein the motion angle measurement circuitry comprises a Global Navigation Satellite System (GNSS) receiver.

19. The system of claim 15 wherein the position-estimation circuitry comprises at least one of:

a Least Square Estimator (LSE) filter;

a Kalman filter;

an extended Kalman filter; and

a particle filter.

20. The system of claim 15, comprising:

a Global Navigation Satellite System (GNSS) receiver; and

a dead reckoning positioning system.

21. A method, comprising:

sensing, using an inertial sensor having at least one inertial sensor behavior parameter dependent on inertial sensor temperature, a current angular rate;

sensing, using a temperature sensor, a time derivative of a temperature of the inertial sensor; and

recursively computing, using one or more processing devices, an estimated current motion angle of a vehicle and at least one estimated inertial sensor behavior parameter as function of;

an indication of a measured current motion angle;

a previously estimated motion angle;

the current angular rate; and

the time derivative of the temperature.

22. The method of claim 21 wherein the at least one inertial sensor behavior parameter comprises at least one of the following parameters:

inertial sensor sensitivity; and

inertial sensor zero-rate level.

23. The method of claim 21, comprising:

generating, using the one or more processing devices, vehicle position information based on a Global Navigation Satellite System (GNSS) receiver signal and a dead reckoning positioning system signal.