Anti-pinch power window system and method

• US 6,366,042 B1
• Filed: 02/14/2001
• Issued: 04/02/2002
• Est. Priority Date: 02/14/2001
• Status: Expired due to Term

• Current Assignee: Continental Automotive Systems, Inc. (Continental AG)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Gerbetz, Robert
• Primary Examiner(s): Nappi, Robert E.
• Assistant Examiner(s): Leykin, Rita
• Application Number:
  US09/783,342
• Time in Patent Office: 412 Days
• Field of Search: 318/445, 318/466, 318/470, 318/266, 318/268, 318/286, 49/26, 49/28
• US Class Current: 318/286
• 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 2400/31 Force or torque control
• CPC Class Codes: E05Y 2400/53 Wing impact prevention or reduction
• CPC Class Codes: E05Y 2900/55 Windows
• 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

A method (100) for closing a motor-driven window comprises the steps of determining (102) a window gap, and raising (104) the window at a speed dependent upon the window gap. The speed is selected based on the window gap and is reduced as the window gap approaches a pinch region such that the pinch-force is limited to a safe value. A vehicle power-window system (400) comprises a window assembly (410), a battery (420), an electric motor (430), a mechanical assembly (440), and a control circuit (450). Control circuit (450) monitors the window gap and supplies drive voltage to the electric motor in dependence on the window gap, so as to control the speed of the window in accordance with the disclosed method (100). Preferably, control circuit (450) includes a regulator circuit (460) and a processor (470), and the drive voltage is substantially unaffected by at least some changes in the battery voltage.

Claims

1. A method for closing a motor-driven window, the window comprising window glass and a window frame, the method comprising the steps of:

determining a window gap, wherein the window gap is defined as a distance between an upper edge of the window glass and a corresponding top portion of the window frame; and

raising the window at a speed dependent upon the window gap, wherein the speed is set at;

a first speed, while the window gap is greater than a first value;

a second speed that is less than the first speed, while the window gap is less than the first value but greater than a second value;

a third speed that is less than the first speed and the second speed, while the window gap is less than the second value but greater than the third value; and

a fourth speed that is greater than the third speed, while the window gap is less than the third value but greater than zero.

2. The method of claim 1, wherein the second speed is reduced as the window gap is reduced from the first value to the second value.

3. The method of claim 1, wherein the second speed is reduced in a substantially stepwise manner as the window gap is reduced from the first value to the second value.

4. The method of claim 1, wherein the third speed is set at a predetermined level such that, in response to a physical obstruction introduced between the window frame and the upper edge of the window glass while the window gap is between the second value and the third value, the pinch force exerted on the obstruction by the window will be limited to less than about one hundred newtons.

5. The method of claim 1, wherein:

the first value corresponds to a window gap of greater than about 60 millimeters;

the second value corresponds to a window gap of less than about 60 millimeters and greater than about 30 millimeters;

the third value corresponds to a window gap of less than about 30 millimeters and greater than about 4 millimeters; and

the fourth value corresponds to a window gap of less than about 4 millimeters.

6. In a system wherein a window, comprising window glass and a window frame, is opened and closed via an electric motor and at a speed that is a function of a voltage applied to the electric motor, a method for closing the window, comprising the steps of:

determining a window gap, wherein the window gap is defined as a distance between an upper edge of the window glass and a corresponding top portion of the window frame; and

adjusting the voltage applied to the electric motor in dependence on the window gap, wherein;

when the window gap is greater than a first value, the voltage is set at a first voltage;

when the window gap is less than the first value but greater than a second value, the voltage is set at a second voltage that is monotonically adjusted as the window gap is reduced;

when the window gap is less than the second value but greater than a third value, the voltage is set at third voltage; and

when the window gap is less than the third value but greater than zero, the voltage is set at a fourth voltage.

7. The method of claim 6, wherein:

an increase in the voltage applied to the electric motor effectuates an increase in the speed at which the window closes; and

a reduction in the voltage applied to the electric motor effectuates a reduction on the speed at which the window closes.

8. The method of claim 7, wherein:

the third voltage is substantially less than the first voltage; and

as the window gap is reduced from the first value to the second value, the second voltage is reduced from an initial value approximately equal to the first voltage to a final value approximately equal to the third voltage.

9. The method of claim 8, wherein the second voltage is reduced via multiple stepwise reductions as the window gap is reduced from the first value to the second value.

10. The method of claim 6, wherein the third voltage is selected such that, in response to introduction of a physical obstruction between the window frame and the upper edge of the window glass while the window gap is between the second value and the third value, the pinch force exerted on the obstruction by the window will be limited to less than about one hundred newtons.

11. The method of claim 6, wherein:

the first value is about 60 millimeters;

the second value is about 30 millimeters; and

the third value is about 4 millimeters.

12. A vehicle power-window system, comprising:

a window assembly comprising;

window glass, a window frame, and a sensor, wherein the distance between an upper edge of the window glass and a corresponding top portion of the window frame defines a window gap, and the sensor is operable to provide a signal indicative of the window gap;

a battery operable to supply a battery voltage;

an electric motor having a rotatable shaft and a pair of input terminals adapted to receive a drive voltage, wherein the speed of rotation of the shaft is a function of the drive voltage;

a mechanical assembly coupling the shaft of the electric motor to the window, and operable to open and close the window in response to rotation of the shaft; and

a control circuit coupled between the battery and the input terminals of the electric motor, wherein the control circuit has a control input for receiving the signal from the sensor that is indicative of the window gap, and is operable to supply drive voltage to the electric motor in dependence on the window gap, wherein;

when the window gap is greater than a first value, the drive voltage is set at a first voltage;

when the window gap is less than the first value but greater than a second value, the drive voltage is set at a second voltage that is monotonically adjusted as the window gap is reduced;

when the window gap is less than the second value but greater than a third value, the drive voltage is set at third voltage; and

when the window gap is less than the third value but greater than zero, the drive voltage is set at a fourth voltage.

13. The system of claim 12, wherein:

the third voltage is substantially less than the first voltage; and

as the window gap is reduced from the first value to the second value, the second voltage is reduced via multiple stepwise reductions from an initial value that is approximately equal to the first voltage to a final value that is approximately equal to the third voltage.

14. The method of claim 12, wherein the third voltage is selected such that, in response to introduction of a physical obstruction between the window frame and the upper edge of the window glass while the window gap is between the second value and the third value, the pinch force applied to the obstruction by the window will be limited to less than about one hundred newtons.

15. The method of claim 12, wherein:

the first value is about 60 millimeters;

the second value is about 30 millimeters; and

the third value is about 4 millimeters.

16. The system of claim 12, wherein the drive voltage supplied to the electric motor by the control circuit is substantially unaffected by at least some changes in the battery voltage.

17. The system of claim 12, wherein the control circuit comprises a regulator circuit coupled between the battery and the input terminals of the electric motor, the regulator circuit having a duty cycle that is adjusted in response to the values of the window gap and the battery voltage.

18. The system of claim 17, wherein the drive voltage supplied to the electric motor is a function of the battery voltage and the duty cycle of the regulator circuit.

19. The system of claim 17, wherein the control circuit further comprises a processor that is coupled to the regulator circuit, the battery, and the control input, wherein the processor implements a look-up table that yields values for the duty cycle corresponding to predetermined combinations of values for the window gap and the battery voltage.

20. The system of claim 19, wherein, in response to an increase in the battery voltage above its nominal value, the processor reduces the duty cycle of the regulator circuit such that the drive voltage supplied to the electric motor remains substantially unaffected by the increase in the battery voltage.