Gravity compensation improvement for power closure member motion control

A method of controlling movement of a closure member of a vehicle between open and closed positions relative to a vehicle body using a power closure member actuation system, comprising the steps of:

• determining a steady state gravitational force on the closure member according to an orientation of the vehicle using at least one closure member accelerometer while the closure member is in a predetermined position and is not moving;
• and
• controlling movement of the closure member by an actuator coupled to the closure member and the vehicle body to compensate for variable gravitational forces on the closure member during the movement of the closure member, the variable gravitational forces used to control the movement being predetermined and selected according to a position of the closure member and the steady state gravitational force.

A control system for power closure member actuation system for moving a closure member of a vehicle between an open position and a closed position relative to a vehicle body, the control system comprising:

• a controller configured to control an actuator coupled to the closure member and the vehicle body configured to move the closure member relative to the vehicle body;
• a closure member accelerometer configured to output an accelerometer signal to the controller indicative of an inclination of the closure member;
• wherein the controller is adapted to compensate for a change in the inclination of the closure member during controlling the actuator to move the closure member using the accelerometer signal acquired during a steady state of the closure member.