VEHICULAR STEERING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a vehicular steering device controlling a motor as a drive source by a new control system without using any rotational angle sensor.

SOLUTION: A motor is driven by the γ-axis current Iγof the γδ coordinate system which is an imaginary rotating coordinate system. The γδ coordinate system follows the control angle θCas the rotational angle on the control. The difference between the control angle θCand the rotor angle θMis the load angle θL. The assist torque TAaccording to the load angle θLis generated. On the other hand, the additional angle α is generated so that the steering torque T is fed back, and the steering torque T is brought close to the indicated steering torque T*. The additional angle α is added to the previous value θC(n-1) of the control angle θCto obtain the present value θC(n) of the control angle θC. A gain setting unit 43 sets the gain G for correcting the γ-axis indicated current value Iγ*based on the deviation ΔYR between the target yaw rate YR*and the real yaw rate YR.

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