Method of controlling the mode of driving electric vehicles

Abstract

A method of controlling the mode of driving an electric vehicle so that the electric vehicle is accelerated at a maximum acceleration and is decelerated at a maximum deceleration. The mode of variation of the running speed of the electric vehicle is estimated on the basis of the variation of the running speed of the electric vehicle calculated from the revolving speeds of the axles of the electric vehicle detected by revolving speed detectors associated with the axles, respectively. The axles are controlled for minute idle rotation or minute slip on the basis of the estimated mode of variation of the running speed of the electric vehicle to produce a maximum effective adhesion between the wheels attached to the axles and the rail so that the acceleration of the electric vehicle at a maximum acceleration and the deceleration of the same at a maximum deceleration are achieved. The torque of the axle carrying the greatest axle load among the driving axles of the electric vehicle is reduced intermittently or continuously so that the wheel attached to this axle is brought into steady rolling contact with the rail to calculate the estimated mode of variation of the running speed on the basis of a time interval between two successive torque reducing operations by means of a microprocessor or the like. Thus, the mode of driving an electric vehicle can be accurately controlled to produce a maximum effective adhesion through calculation based on the revolving speed of the axle.