Anti-Trap Protection Detection Based on Comparing the Duty Cycle of a PWM Control System

• US 20070003258A1
• Filed: 06/26/2006
• Published: 01/04/2007
• Est. Priority Date: 06/30/2005
• Status: Active Grant

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Siemens AG
• Inventors: Franzan, Gunter
• Granted Patent: US 7,346,272 B2
• Time in Patent Office: Days
• US Class Current: 388/803
• CPC Class Codes: E05F 15/41 Detection by monitoring transmitted force or torque E05F15/48 takes precedence; Safety couplings with activation dependent upon torque or force, e.g. slip couplings
• CPC Class Codes: E05Y 2900/50 for vehicles
• CPC Class Codes: E05Y 2900/546 Tailgates
• CPC Class Codes: H02H 3/006 Calibration or setting of parameters
• CPC Class Codes: H02H 7/0833 for electric motors with control arrangements
• CPC Class Codes: H02H 7/0851 for motors actuating a movable member between two end positions, e.g. detecting an end position or obstruction by overload signal

Abstract

In order to create a method and an apparatus for anti-trap protection detection for displaceable window and door elements by means of which faster and more stable adjustment to current physical conditions can be achieved during system actuation, in the system the motor (1) is controlled using parameter values generated in real-time using a closed-loop control unit, preferably a PID controller, to keep the speed in the system constant during a learning run and during operational use and to ensure timely trapping detection.

Claims

1. A method for controlling a displacement element such as a vehicle window, a sunroof, a lift gate, a vehicle door or the like by means of a motor, the method comprising the step of:

comparing parameter values which are stored by means of a learning run with parameter values generated in real-time during operation of the motor and,

depending on the result of the comparison, stopping the motor or reversing the motor rotational direction,

wherein the speed of the motor is kept constant allowing for the mechanical forces actually occurring on the displacement element at the time of motor actuation and the parameter values generated in real-time are the result of closed-loop speed control causing the speed to remain constant and are used for controlling the motor.

2. A method according to claim 1, wherein the motor is a DC motor.

3. A method according to claim 1, wherein the parameter values are in the form of a characteristic curve.

4. A method according to claim 1, wherein the parameter values generated in real-time are the ratio of the on-time of the motor to the off-time of the motor.

5. A method according to claim 1, wherein, if a defined difference between the stored parameter values and the parameter values generated in real-time is exceeded, the motor is stopped and its drive motion is preferably put into reverse.

6. A method according to claim 1, wherein the parameter values stored by means of a learning run are the ratio of the on-time of the motor to the off-time of the motor.

7. A method according to claim 1, wherein the speed of the system is maintained constant throughout the learning run.

12. A method for generating parameter values of a learning run for use in a method according to claim 1, wherein the speed of the motor is kept constant by means of a closed-loop control unit, preferably a PID controller.

13. A method according to claim 12, wherein the travel path of the displacement element is subdivided into a plurality of sections within which an average of the parameter values required for controlling the motor while its speed is maintained constant is calculated, the difference between the current parameter value and the previously stored parameter value being stored in the nonvolatile memory at the end of the section.

14. A method according to claim 13, wherein the totality of all the stored parameter values is stored as a characteristic in the nonvolatile memory.

15. A method according to claim 13, wherein the parameter values are the ratio of the on-time of the motor to the off-time of the motor.

8. An apparatus for controlling a displacement element such as a vehicle window, a sunroof, a lift gate, a vehicle door or the like by means of a motor, an open-loop control unit for motor clocking and a characteristic handler as well as a nonvolatile memory in which parameter values obtained in the course of a learning run are stored, wherein the open-loop control unit is preceded by a closed-loop control unit which causes the motor to operate at constant speed, the characteristic handler continuously comparing the parameter values of the open-loop control unit that are critical for motor control with the parameter values stored in the nonvolatile memory.

9. An apparatus according to claim 8, wherein the motor is a DC motor.

10. An apparatus according to claim 8, wherein the parameter values are in the form of a characteristic curve.

11. An apparatus according to claim 8, wherein the closed-loop control unit comprises a PID controller.

16. A method for generating parameter values of a learning run for use in an apparatus according to claim 8, wherein the speed of the motor is kept constant by means of a closed-loop control unit, preferably a PID controller.

17. A method according to claim 16, wherein the travel path of the displacement element is subdivided into a plurality of sections within which an average of the parameter values required for controlling the motor while its speed is maintained constant is calculated, the difference between the current parameter value and the previously stored parameter value being stored in the nonvolatile memory at the end of the section.

18. A method according to claim 17, wherein the totality of all the stored parameter values is stored as a characteristic in the nonvolatile memory.

19. A method according to claim 17, wherein the parameter values are the ratio of the on-time of the motor to the off-time of the motor.