Motor speed-based anti-pinch control apparatus and method with start-up transient detection and compensation

• US 6,794,837 B1
• Filed: 05/31/2002
• Issued: 09/21/2004
• Est. Priority Date: 05/31/2002
• Status: Active Grant

• Current Assignee: Valeo Electrical Systems Incorporated (Valeo SE)
• Original Assignee: Valeo Electrical Systems Incorporated (Valeo SE)
• Inventors: Everhart, Jon C. Jr., Caussat, Thierry, Wenrick, David M., Whinnery, Joseph P.
• Primary Examiner(s): Martin, David
• Assistant Examiner(s): San Martin, Edgardo
• Application Number:
  US10/159,171
• Time in Patent Office: 844 Days
• Field of Search: 318/282, 318/265, 318/266, 318/468, 318/286, 318/54, 318/65, 49/28, 49/26
• US Class Current: 318/282
• 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 2400/564 sensing motor speed
• CPC Class Codes: E05Y 2900/531 Doors
• CPC Class Codes: E05Y 2900/542 Roof panels
• CPC Class Codes: E05Y 2900/546 Tailgates
• CPC Class Codes: E05Y 2900/55 Windows
• CPC Class Codes: H02H 1/04 Arrangements for preventing response to transient abnormal conditions, e.g. to lightning or to short duration over voltage or oscillations; Damping the influence of dc component by short circuits in ac networks
• 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 control apparatus and method for a panel movable between at least two positions by an electric motor having a rotatable armature. The control generates time periods for the rotation of the armature over a constant angular distance. An average time period is computed over a predetermined number of time periods and compared with a threshold time period to determine if an obstacle is present in the path of movement of the closure. Transient counts are accumulated for increasing average time periods over a number of time period samples to detect an obstacle. A compensation factor is used to adjust a threshold upon detecting a start-up transient during an initial movement of the motor armature coupled to the panel to delay activation of obstacle detection until the start-up transient diminishes.

Claims

1. A powered movable panel control apparatus for a panel movable between first and second positions by an electric motor having an armature coupled to the panel, the armature including a magnet having a plurality of poles, the control apparatus comprising:

means for detecting deceleration of a motor armature;

timer means, responsive to the detecting means, for generating consecutive time periods between a predetermined amount of rotation of the armature over at least a portion of one complete revolution of the armature;

means, responsive to the timer means, for calculating an average time period over the predetermined number of time periods;

means, responsive to the average time period, for calculating the deceleration of the motor armature between two average time periods of the armature rotation;

means for comparing the deceleration with a threshold defining normal motor decelerations resulting from motor armature load variations;

means responsive to a comparison exceeding armature load threshold for classifying the deceleration as a relative deceleration with respect to the threshold;

means for assigning a weighted value based on the relative deceleration with respect to the threshold;

means for accumulating successive weighted values as a total cumulative weighted value;

means for comparing the total cumulative value to a defined obstacle detection weighted value;

means, responsive to the comparing means, for generating a signal to reverse the direction of movement of the panel when the total cumulative weighted value exceeds the defined obstacle detection weighted value;

means for determining when the change in the average time period begins to decrease in magnitude after reaching a peak magnitude; and

means, responsive to an affirmative output from the determining means, for activating the deceleration comparing means.

2. The system of claim 1 wherein:

the average time period is calculated over the passage eight poles past the sensor.

3. The apparatus of claim 1 wherein:

the average time period is calculated for eight successive poles of a total of sixteen successive poles passing the sensor.

4. The apparatus of claim 1 wherein the means for determining when the average time period begins to decrease further comprising the steps of:

means for measuring the rate of change between successive average time periods;

means for storing the largest change in slope between successive average time periods;

means for determining if the difference between successive average time periods is greater than an upper threshold;

means for storing a compensation value increased by the smallest rate of change between successive average time periods;

means for adding a compensation value to the threshold;

means for detecting a decrease in the rate of change of the average time period; and

means responsive to a peak magnitude of the average time period for decreasing the compensation value by the largest rate of change between successive average time periods until the compensation value is zero.

5. A method for controlling a powered panel movable between first and second positions comprising the steps of:

detecting deceleration of a motor armature driving the panel generating consecutive time periods for rotation of the armature through a constant angular distance during at least a portion of one complete revolution of the armature;

calculating an average time period over the predetermined number of time periods;

calculating the deceleration of the motor armature;

comparing the deceleration with a threshold defining an obstacle in the path of movement of the panel;

reversing the motor when the deceleration is greater than or equal to the threshold;

calculating the average time period over a predetermined constant number of successive time periods;

determining when the change in average time period begins to decrease in magnitude after reaching a peak magnitude; and

in response to an affirmative output from the determining step, activating the deceleration comparing step.

6. The method of claim 5 further comprising the steps of:

measuring the rate of change between successive average time periods;

storing the largest rate of change between successive average time periods;

determining if the difference between successive average time periods is greater than an upper threshold;

storing a compensation value increased by the smallest rate of change between successive average time periods;

adding a compensation value to the threshold;

detecting a decrease in the rate of change of the average time period; and

in responsive to the peak detection means for decreasing the compensation value by the largest rate of change between successive average time periods until the compensation value is zero.