| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric power steering device which responds to a change in friction with time or weather so as to allow comfortable operation of the electric power steering device and a vehicle having the same and to prevent accidents from occurring by releasing alerts upon significant change in frictional force. SOLUTION: In the electric power steering device 1, a control unit 17 estimates a frictional force by determining an upper-limit motor current value based on whether an assist motor 15 rotates when a torque sensor 12 detects that a vehicle is moving straight and an input vehicle speed v has been within a predetermined range of friction detecting speed for more than a reference straight driving time period, and changes the control characteristics of an assist control function according to the estimated frictional force. COPYRIGHT: (C)2004,JPO |
