Electric power steering device

摘要

An object of the present invention is to provide an electric power steering device which reduces the variation of viscous feeling due to the change of steering velocity and presents better steering feeling than conventional power steering devices. A basic assist torque Tab and the like are calculated; filter parameters such as time constant Tn are calculated; and a gain Gs is calculated. A steering velocity s·θis calculated and a correction torque Tcmps is calculated as a product of a gain Gs and a value obtained by filtering steering velocity s·θwith a filter of second-order lag and first-order advance. Further, a final target assist torque Ta is calculated by summing a basic assist torque Tab and the like and a correction torque Tcmps, and a steering assist torque is controlled so that it conforms to the final target assist torque Ta.