Road-surface friction coefft. determination method

摘要

The pump motor (104) is part of a brake installation, with a control unit (106) and the wheel RPM sensors (107vr,107vl,107hr,107hl) for supplying the RPMs (Nij) to the brake control unit (106). According to the RPMs and other parameters, the main brake cylinder's inlet and outlet valves are controlled, to increase or decrease the brake pressure. The brake control unit receives from the unit (105) the signals (SRW) representing the coefficient of friction of the road and the main cylinder pressure (PHZ) and also the outlet valve's control signals (AV). The re-circulating pump (103), driven by the pump motor, receives from the units (101,102) the actual and the required pump RPM and acts as a regulator (R), giving beat signal (PWM) to control the pump. On the basis of the information, the brake control unit opens or closes the inlet and outlet valves (EV/AV) on the wheel cylinders (4vr,4vl,4hr,4hl).