Method for calibrating an angle sensor and navigation system having an angle sensor

• US 6,374,190 B2
• Filed: 12/29/2000
• Issued: 04/16/2002
• Est. Priority Date: 06/29/1998
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Schupfner, Markus
• Primary Examiner(s): Hoff, Marc S.
• Assistant Examiner(s): Raymond, Edward
• Application Number:
  US09/751,956
• Publication Number:
  US 20010003170A1
• Time in Patent Office: 473 Days
• Field of Search: 702/57, 702/85, 702/87, 702/88, 702/92-95, 702/99, 702/97, 702/104, 702/107, 702/130, 702/133.6, 702/149, 702/150-153, 702/158, 702/183, 702/188, 702/189
• US Class Current: 702/94
• CPC Class Codes: G01C 19/00 Gyroscopes; Turn-sensitive devices using vibrating masses; Turn-sensitive devices without moving masses; Measuring angular rate using gyroscopic effects
• 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

Abstract

A method for calibrating an angle sensor ascertains an output signal for a zero point and measures an associated operating temperature. The output signal and a reference signal stored for the operating temperature are used to form a new reference signal. A navigation system equipped with a temperature sensor for measuring the operating temperature of the angle sensor and with a memory for storing reference signals is also provided. The calibration method and the navigation system substantially eliminate angle sensor measurement errors attributed to temperature influences.

Claims

1. A method for calibrating an angle sensor influenced by an operating temperature, the method which comprises:

ascertaining an output signal for a zero point of an angle sensor and measuring an operating temperature associated with the angle sensor;

forming a new reference signal from the output signal and from a reference signal for the zero point provided for the operating temperature;

storing the new reference signal;

recording a respective number indicating how often storage operations for reference signals have been performed for each of a plurality of temperatures;

determining an influence of the reference signal for the zero point stored for a given temperature on a formation of the new reference signal based on the respective number indicating how often the storage operations have been performed; and

setting the zero point of the angle sensor by using the new reference signal.

2. The method according to claim 1, which comprises:

storing signals for the zero point of the angle sensor for a plurality of given temperatures; and

forming, for the operating temperature, the reference signal from a first signal stored for a first temperature lower than the operating temperature and from a second signal stored for a second temperature higher than the operating temperature.

3. The method according to claim 1, which comprises:

converting the new reference signal for the operating temperature back into a first signal for a first temperature lower than the operating temperature and a second signal for a second temperature higher than the operating temperature; and

storing the first signal and the second signal.

4. The method according to claim 1, which comprises forming a scaling factor for the angle sensor based on the reference signal.

5. The method according to claim 1, which comprises using a gyroscope as the angle sensor.

6. The method according to claim 1, which comprises storing, during a manufacturing process, signals for the zero point for given temperatures.

7. A navigation system, comprising:

a processor;

an angle sensor connected to said processor for providing first data to said processor;

a distance sensor connected to said processor for providing second data to said processor;

a temperature sensor connected to said processor for measuring an operating temperature of said angle sensor;

a memory connected to said processor and storing a table for providing reference signals as calibration values for a zero point of the angle sensor for a plurality of given operating temperatures;

said processor being configured for determining a position from the first data from said angle sensor and from the second data from said distance sensor;

said processor being configured for generating, for the operating temperature, a reference signal from a first signal stored for a first temperature lower than the operating temperature and from a second signal stored for a second temperature higher than the operating temperature;

said angle sensor providing an output signal for the zero point, the output signal being measured at the operating temperature, said processor being configured for generating a new reference signal for the operating temperature from the reference signal and from the output signal for the zero point;

said processor converting the new reference signal formed for the operating temperature into a third signal for the first temperature and a fourth signal for the second temperature; and

said memory storing the third signal and the fourth signal.