Precise ascertainment of actuating position for a motor-driven vehicle part

Patent metadata

Field	Value
Publication number	US-9239579-B2
Application number	US-201313863062-A
Country	US
Kind code	B2
Filing date	Apr 15, 2013
Priority date	Apr 14, 2012
Publication date	Jan 19, 2016
Grant date	Jan 19, 2016

Abstract

In order to ascertain the actuating position of a vehicle part that is moved by an electric actuating motor via an actuating mechanism, an angle of rotation correlating with the number of motor shaft rotations during the actuation process or a motor signal correlated therewith are ascertained during an actuation process. An actuating position measure for the actuating position of the vehicle part is derived from the angle of rotation or the motor signal correlating therewith. During this process, an unloaded angle of rotation, through which the motor shaft rotates during an initial no-load phase of the actuation process without motion of the vehicle part is compensated by a predetermined correction term. The correction term is changed according to a stored dependency on a characteristic quantity for the age of the actuating mechanism.

First claim

What is claimed is:

1. A method for ascertaining an actuating position of a vehicle part that is moveable by an electric actuating motor via an actuating mechanism, the method comprising:
ascertaining an angle of rotation correlating a number of motor shaft rotations during an actuation process or a motor signal correlated therewith during the actuation process;
deriving an actuating position measure for the actuating position of the vehicle part from the angle of rotation or the motor signal correlating therewith,
compensating an unloaded angle of rotation, through which the motor shaft rotates during an initial no-load phase of the actuation process without motion of the vehicle part via a predetermined correction term; and
changing the correction term according to a stored dependency on a characteristic quantity for the age of the actuating mechanism,
wherein the correction term is increased linearly as a function of the characteristic quantity for the age of the actuating mechanism until a predetermined maximum value is reached and once the predetermined maximum value is reached, the corrective term is held at a value that is independent of the age of the actuating mechanism.

2. The method according to claim 1 , wherein the number of actuation processes carried out using the actuating mechanism is used as a characteristic quantity for an age of the actuating mechanism.

3. The method according to claim 1 , wherein the correction term is increased by a defined or parameterizable value each time a defined or parameterizable number of actuation processes has taken place until the maximum value is reached.

4. The method according to claim 1 , wherein the correction term additionally is varied as a function of a measured temperature value.

5. The method according to claim 4 , wherein the correction term is varied linearly as a function of the measured temperature value.

6. An actuating device for automatically moving a vehicle part, the actuating device comprising:
an electric actuating motor;
an actuating mechanism that couples the actuating motor to the vehicle part; and
a control unit for driving the actuating motor,
wherein the control unit is configured to automatically carry out the method according to claim 1 .

7. The actuating device according to claim 6 , wherein the actuating mechanism comprises a control cable.

Assignees

• Brose Fahrzeugteile

Inventors

• Schlesiger Markus
• Kalb Roland
• Lieb Martin
• Scholz Marcus
• Bauersachs Steffen
• Straub Christoph
• Russ Detlef
• Weidinger Matthias

Classifications

• G05B24/02 Primary

  electric · CPC title