Adaptive window lift control with pinch force based on object rigidity and window position

• US 5,436,539 A
• Filed: 08/30/1993
• Issued: 07/25/1995
• Est. Priority Date: 08/30/1993
• Status: Expired due to Term

• Current Assignee: Lear Corporation EEDS and Interiors Incorporated (Lear Corporation)
• Original Assignee: United Technologies Automotive, Inc. (Lear Corporation)
• Inventors: Perez, Pedro A., Kelley, Jeffrey T., Wrenbeck, Bruce R.
• Primary Examiner(s): SALATA, ANTHONY J
• Application Number:
  US08/113,295
• Time in Patent Office: 694 Days
• Field of Search: 318/280-286, 318/466-470, 318/602, 318/603, 318/616-618, 318/265, 318/266, 318/272, 318/277, 49/26, 49/28, 49/141, 160/291, 160/292, 160/293.1, 160/310
• US Class Current: 318/265
• 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 power window system employs a computer based control that receives signals from a window position sensor. As the window moves, the position sensor produces periodic signals as an output. The computer cyclically looks for a change in the frequency of the signals as an indication that the window is obstructed and decelerating. Based on the instantaneous deceleration, the computer recalls a stored value for motor force. The recalled forces are accumulated in synchronism with the position sensor output during the deceleration, manifesting the force applied to the obstruction as the window presses on it. The window is reversed when the accumulated force exceeds a stored value. The uppermost window position is a stored value for the position sensor output obtained when the window is closed for the first time. Each time the window is closed thereafter, an offset is added to that value, the sum defining the point at which the window engages the window seal. The offset is the change in the position sensor output signal as the window is slowed by the seal until the motor stops when a stored value of force is applied to the seal.

Claims

1. A window lift system for closing a window against a seal comprising a motor, means for coupling the motor to a window, and a switch for commanding motor operation, characterized by:

a position sensor providing a location signal indicating window movement;

signal processing means responsive to the operation of the switch to provide a signal to operate the motor comprising means for receiving the location signal;

for storing a first value of the location signal indicating the lowest point of window location and a second value for the location signal indicating the highest point of window location;

for providing a deceleration signal from the location signal indicating the rate of change over time for said location signal as the window moves;

for recalling a first stored value of motor force for the magnitude of the deceleration signal at a first time;

for recalling a second stored value of motor force for the magnitude of deceleration at a second successive time interval, for adding said first and second values of motor force;

for stopping the motor if the sum exceeds a stored value when the location signal indicates that the window is no higher than a first stored height and stopping the motor when the force applied by the motor exceeds a second stored value if the location signal indicates that the window is above the first height and is less than the second value, the first height being the sum of the second value and an offset value;

for storing the count when the motor is stopped; and

for storing the offset value each time the window closes against the seal by sensing the change in the location signal between the time the motor starts to decelerate and stop on the seal.

2. The invention described in claim 1, further characterized in that:

the signal processing means comprises means for stopping and reversing the motor when the deceleration of the window exceeds a stored limit and the time between changes in the location signal exceeds a stored limit.

3. A window lift system for closing a window against a seal comprising a motor, means for coupling the motor to a window, and a switch for commanding motor operation, characterized by:

a position sensor for providing a location signal indicating window movement;

signal processing means comprising means responsive to the operation of the switch to provide a signal to operate the motor, and responsive to the location signal for calculating and storing, at successive intervals, distinct motor force values, applied by the window over distance, based on motor deceleration, from the time that window starts to decelerate, for providing a force signal by accumulating said motor force values and for stopping the motor when said force signal exceeds a stored value.

4. The invention described in claim 3, further characterized in that:

the signal processing means comprises means for storing a first value indicating the window location at which the window engages a window seal based on the window deceleration when engaging the seal.

5. The invention described in claim 4, further characterized in that:

the first value is the sum of an offset and a stored value indicating the uppermost window position derived from the location signal when the window is closed for the first time, the offset representing a change in the location signal from the time that the motor begins to decelerate and stops when engaging the seal.

6. The invention described in claim 5, further characterized in that:

the position sensor produces count pulses and the motor force for each count is computed and accumulated to produce a sum indicating window force.

7. The invention described in claim 6, further characterized in that:

the signal processing means comprises means for determining window deceleration from the count pulses and for stopping and reversing the motor when the time between the count pulses exceeds a stored value following a determination that window deceleration exceeds a stored value.

8. A method for installing a window lift system for closing a window against a seal comprising a motor coupled to the window, and a switch for commanding motor operation, characterized by the steps:

sensing window location with a sensor coupled to the window;

sensing motor force;

storing a value for motor force;

producing an actual motor force value by summing incremental motor force values calculated as the motor decelerates when the window engages an object

operating the switch to energize the motor to move the window from its lowest to highest location;

stopping the motor when said stored value of motor force and said actual motor force value are equal;

providing window location signals from the sensor as the window moves and from the location signals storing a value for a window location when the window is at its lowest point, a value for a window location at which the motor begins to slow and a value for a position when the motor is stopped because said stored value of motor force and said actual motor force value are equal.