To prevent the wrong operation of a steering by the influence of the magnetic field of a brake motor or the like to prevent the meandering by setting the pulse width modulation frequency for controlling the brake motor or the like so that its integer-multiplied frequency is largely different, compared with the frequency of a guidepath wire.
In a passenger golf cart, induction currents carried in loop lines buried along a traveling path are detected by lateral induction sensors 10 in automatic steering mode, and a microcomputer 2 performs a steering control so that a guidepath wire is regularly located in the center of the induction sensors by rotating a steering motor 12 to the right when a left slippage is detected and rotating the steering motor 12 to the left when a right slippage is detected. At this time, the pulse width for driving the steering motor 12 is duty controlled by PWM (pulse width modulation) method according to the slippage. The integer-multiplied frequency of the PWM frequency for controlling the steering motor 12 or the like is set sufficiently large than the guidepath wire frequency.
MATSUSHITA TAKEYA
UENISHI TOMOAKI
YAMADA TOMOHIRO
MATSUOKA KAZUHIRO
