Patent ID: 7793752
Filing Date: 2010-09-14
Classification: B62D

Abstract:
1. A method of determining a direction of a power boost applied to a power cylinder in a power steering system coupled to a hand wheel with the power steering system further including a pump, a control valve in fluid communication with and disposed between the pump and the power cylinder, a fluid circulating through the power steering system, and a pressure sensor disposed between the pump and the control valve, said method comprising the steps of: defining an equilibrium pressure range of the fluid to indicate when the fluid is circulating through the power steering system without providing the power boost; measuring a pressure of the fluid between the pump and the control valve; comparing the measured pressure of the fluid to the equilibrium pressure range to determine if the measured pressure of the fluid is within the equilibrium pressure range; detecting a first angular position of the hand wheel in response to the measured pressure being within the equilibrium pressure range; detecting a second angular position of the hand wheel in response to rotation of the hand wheel; subtracting the second angular position of the hand wheel from the first angular position of the hand wheel to obtain a differential value; evaluating by a controller, the differential value to determine the direction of the power boost applied to the power cylinder; and controlling the power steering system based on the direction.