Auto up window with osbtacle detection system

• US 5,585,702 A
• Filed: 11/03/1995
• Issued: 12/17/1996
• Est. Priority Date: 11/03/1995
• Status: Expired due to Fees

• Current Assignee: ITT Automotive Electrical Systems, Inc. (ITT, Inc.)
• Original Assignee: ITT Automotive Electrical Systems, Inc. (ITT, Inc.)
• Inventors: McCann, Roy A., Jackson, James A.
• Primary Examiner(s): Ro, Bentsu
• Application Number:
  US08/552,669
• Time in Patent Office: 410 Days
• Field of Search: 318/264, 318/265, 318/266, 318/286, 318/466, 318/467, 318/468, 318/469, 318/471, 388/903, 388/907.5, 388/934, 307/10.1, 49/26, 49/28
• US Class Current: 318/266
• 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 closure system for a motor vehicle includes a closure, a closure frame, an electric motor, a control switch, an electrical power source, first and second displacement sensors, a temperature sensor, a current sensor for a current being drawn by the electric motor, and a microprocessor. The first and second displacement sensors each operably generate a signal indicative of closure movement. The microprocessor is electrically connected to the control switch, the electric motor, the first and second displacement sensors, the temperature sensor and the current sensor. The microprocessor electrically connects the motor with the power source responsive to a condition of the control switch. The microprocessor also converts the temperature sensed to an electrical signal indicative of the temperature, and converts the current sensed to an electrical signal indicative of motor current. The microprocessor uses the signals for current and temperature to calculate a temperature compensated drag force of the closure at a number of predetermined closure positions. The microprocessor determines the closure position by using signals from the displacement sensors. The microprocessor compares the temperature compensated drag force with a reference drag force and reverses the motor when the compensated drag force is greater than the reference drag force.

Claims

1. A power closure system for a motor vehicle comprising:

a closure;

a closure frame defining a seated position of the closure;

a control switch;

an electrical power source including a battery;

an electric motor with an output shaft drivingly connected to the closure and selectively electrically connected to the power source;

a first displacement sensor operably generating a signal indicative of one of closure movement and output shaft rotation;

a second displacement sensor operably generating a signal indicative of one of closure movement and output shaft rotation;

means for sensing a temperature;

means for sensing a current being drawn by the electric motor; and

a microprocessor electrically connected to the control switch, the electric motor, the first and second displacement sensors, the means for sensing a temperature and the means for sensing a current, and including

means for electrically connecting the motor with the power source responsive to a condition of the control switch;

means for converting signals from the displacement sensors into a predetermined number of closure positions;

means for converting temperature sensed to an electrical signal indicative of the temperature at one of the closure positions;

means for converting current sensed to an electrical signal of motor current at the one of the closure positions;

means for calculating a drag force of the closure as the closure approaches the one of the closure positions;

means for calculating a temperature correction factor using the electrical signal indicative of the temperature and a predetermined reference temperature;

means for calculating a compensated drag force for the one of the closure positions using the calculated drag force and the temperature correction factor; and

means for comparing the compensated drag force with a reference drag force for the one of the closure positions and electing to reverse the motor when the compensated drag force is greater than the reference drag force.

2. A power closure system for a motor vehicle as claimed in claim 1 wherein the means for comparing the compensated drag force with a reference drag force and electing to reverse the motor when the compensated drag force is greater than the reference drag force elects to reverse the motor when the compensated drag force is greater than the reference drag force by a predetermined amount.

3. A power closure system for a motor vehicle as claimed in claim 2 further comprising:

means for revising the reference drag force by including the compensated drag force therein when there is not an election to reverse the motor.

4. A power closure system for a motor vehicle as claimed in claim 2 further comprising:

means for calculating upper and lower second drag force range values by multiplying the reference drag force by predetermined upper and lower second range factors and revising the reference drag force by including the compensated drag force therein when the compensated drag force is between the upper and lower second drag force range values when there is not an election to reverse the motor.

5. A power closure system for a motor vehicle as claimed in claim 1, wherein the means for comparing the compensated drag force with a reference drag force and electing to reverse the motor when the compensated drag force is greater than the reference drag force includes:

means for comparing the compensated drag force with a reference drag force and electing to increment a pulse count when the compensated drag force is less than the reference drag force and to clear the pulse count when the compensated drag force is greater than the reference drag force; and

means for comparing the incremented pulse count to a predetermined set count and electing to reverse the motor when the incremented pulse count equals the set count.

6. A power closure system for a motor vehicle as claimed in claim 3, wherein the means for comparing the compensated drag force with a reference drag force and electing to reverse the motor when the compensated drag force is greater than the reference drag force includes:

means for comparing the compensated drag force with the reference drag force and electing to increment a pulse count when the compensated drag force is greater than the reference drag force and to clear the pulse count when the compensated drag force is less than the reference drag force; and

means for comparing the incremented pulse count to a predetermined set count and electing to reverse the motor when the incremented pulse count equals the set count.

7. A power closure system for a motor vehicle as claimed in claim 3, wherein the means for comparing the compensated drag force with a reference drag force and electing to reverse the motor when the compensated drag force is greater than the reference drag force includes:

means for comparing the compensated drag force with the reference drag force and electing to increment a pulse count when the compensated drag force is greater than the reference drag force, and for clearing the pulse count and calculating upper and lower second drag force range values by multiplying the reference drag force by predetermined upper and lower second range factors when the reference drag force is less than the predetermined threshold reference drag force;

means for comparing the compensated drag force with the upper and lower second drag force range values and revising the reference drag force when the compensated drag force is between the upper and lower second drag force range values; and

means for comparing the incremented pulse count to a predetermined set count and electing to reverse the motor when the incremented pulse count equals the set count.

8. A power closure system for a motor vehicle as claimed in claim 1, wherein:

means for calculating the temperature correction factor as equal to the quantity (1+K_T (T-T_o)) with K_T equal to a predetermined temperature correction constant and T_o equal to reference temperature and T equal to a temperature sensed at the closure position, and the calculated drag force being divided by the temperature correction factor in calculating the compensated drag force.

9. A method for controlling closure movement in a motor vehicle employing an electric drive motor controlled by a microprocessor including:

mounting a first displacement sensor in a first position relative to a shaft of the electric drive motor;

mounting a second displacement sensor in a second position relative to the shaft of the electric drive motor;

using the first displacement sensor and the second displacement sensor to provide an indication of closure direction and position;

using the microprocessor to calculate a drag force of one of the closure and the motor at a predetermined closure position;

sensing a temperature and converting the temperature sensed to an electrical signal indicative of the temperature at the predetermined closure position;

using the microprocessor to calculate a temperature correction factor by comparing the electrical signal indicative of temperature and a stored reference temperature;

sensing a current and converting the current sensed to an electrical signal of current drawn by the motor at the predetermined closure position;

using the microprocessor to calculate a compensated drag force for the predetermined closure position by dividing the calculated drag force by a temperature correction factor; and

comparing the compensated drag force with a reference drag force for the predetermined closure position and electing to reverse the motor when the compensated drag force is greater than the reference drag force.