Electronic controller for vehicle power assisted steering servo - has processor which produces excitation current to electromagnetic clutch of hydraulic servo pump

摘要

A small dc source cooperates with the steering wheel of the vehicle to produce a current proportional to its degree of rotation. An engine speed detector produces analogue signals which are fed to an electronic controller, which also receives the current generator signals, together with signals representing the vehicle speed. When the steering wheel is moved, a fraction of the current generator output, and that of the other two detectors, is amplified and fed to an electromagnetic clutch. The control is such that when the vehicle is stationary, an excitation current to the solenoid of the clutch acquires its maximum value, in oder to transmit diving power to the hydraulic pump of the senomechanism. When the vehicle speed increases, the excitation decreases to increase the amount of clutch slippage. The degree of power assistance to the vehicle wheels is thus controlled to be nvesely propotional to the speed of the vehicle.