Method of Calibrating a Position Sensor in a Motor Vehicle Gear

• US 20110110392A1
• Filed: 07/15/2009
• Published: 05/12/2011
• Est. Priority Date: 07/16/2008
• Status: Active Grant

• Current Assignee: Rollax GmbH & Co. KG
• Original Assignee: Rollax GmbH & Co. KG
• Inventors: Ullrich, Thomas, Rösch, Wolfgang
• Granted Patent: US 8,662,744 B2
• Time in Patent Office: Days
• US Class Current: 374/1
• CPC Class Codes: F16H 2061/283 Adjustment or calibration of actuator positions, e.g. neutral position
• CPC Class Codes: F16H 59/70 dependent on the ratio established
• CPC Class Codes: F16H 63/38 Detents spring-loaded ball units for holding levers in a limited number of positions G05G5/065

Abstract

A method of calibrating a position sensor in an automotive transmission having a transmission housing having mounted therein a casing (10) for the position sensor which includes a pressure member (14) movably supported in the casing (10), and an electrical displacement sensor (38) actuated by the pressure member (14) for measuring the position of the pressure member (14) relative to the casing (10), such that, after the casing (10) of the position sensor has been mounted in the transmission housing, the displacement sensor (38) is used for performing at least one calibration measurement for at least one gear position, and, for each gear position to be detected, a tolerance range for the corresponding measurement value of the displacement sensor is defined on the basis of the result of the calibration measurement.

Claims

1. A method of calibrating a position sensor in an automotive transmission having a transmission housing having mounted therein a casing for the position sensor which comprises a pressure member movably supported in the casing, and an electrical displacement sensor actuated by the pressure member for measuring the position of the pressure member relative to the casing, comprising the steps of:

performing at least one calibration measurement with the displacement sensor for at least one gear position, after the casing of the position sensor has been mounted in the transmission housing, and

defining a tolerance range for a value of the corresponding calibration measurement of the displacement sensor on the basis of the result of the calibration measurement, for each gear position to be detected.

2. The method according to claim 1, wherein said step of performing includes the step of performing at least one said calibration measurement for each gear position to be detected.

3. The method according to claim 1, further comprising the step of continually correcting the tolerance ranges on the basis of the results of actual position measurements while the transmission is operating.

4. The method according to claim 1, further comprising the steps of:

measuring the temperature of the transmission housing, and

correcting the result of the displacement measurement for thermal expansions of component parts of at least one of the transmission and the sensor.

5. The method according to claim 1, further comprising the steps of:

measuring the temperature of the displacement sensor, and

correcting the result of the displacement measurement for a temperature drift of the displacement sensor.

6. The method according to claim 4, further comprising the step of measuring the temperature of an evaluation electronics integrated in the casing of the position sensor as a temperature representative of the temperature of the position sensor and the transmission housing.

7. The method according to claim 5, wherein an inductive sensor is used as the displacement sensor.

8. The method according to claim 5, further comprising the step of measuring the temperature of an evaluation electronics integrated in the casing of the position sensor as a temperature representative of the temperature of the position sensor and the transmission housing.

9. The method according to claim 6, wherein an inductive sensor is used as the displacement sensor.