Hydraulic circuit control of a steer by wire system

The future of cars will be connected with "by-wire" systems. The Technical University of Liberec, Department of vehicles and Engines has developed a design of testing equipment for directional control system testing. The objective of the newly designed equipment is to incorporate a wheel with a real tire and a flexible mounting of axle components. The paper describes properties and control of the hydraulic circuit consisting of two double-acting engines with a unilateral piston rod and two proportional valves (Parker D1FP). Each of the front axle wheels is controlled separately. The paper illustrates relationships andpotential of steer-by-wire systems at the experimental equipment. The safe and easy control of a vehicle undoubtedly poses significant requirements. Satisfying them and improving the design to enhance the vehicle's stability have always belonged to the primary objectives of designer s. Consequently, the chassis characteristics, the mechanical features of wheel suspensions, the quality of air suspensions, but also speed control (including brakes) and the vehicle 's directional control have always been emphasised. The objective of the paper was to design a steer-by-wire directional control mechanism with a suitable arrangement. The comparison focuses on various design options to arrange the action members (actuators) of this mechanism.