“A self-propelled grass mower and a self-propelled wheeled apparatus that can perform precise guidance control by reliably detecting a guidance signal with a guidewire are provided. The self-propelled grass mower includes wheel motors for driving wheels, a cutting blade motor for driving a cutting blade, a rechargeable battery for supplying electrical power to these motors, and a guidewire sensor for detecting a magnetic field generated by a guidewire formed into a loop. In the self-propelled grass mower that detects whether is inside or outside of a region enclosed by the guidewire and runs autonomously in a grass cutting region, only the supply voltage for the cutting blade motor is reduced when a magnetic field is detected by the guidewire sensor. Driving of the cutting blade motor is restarted after detection of the magnetic field has completed. Thereby, the impact of noise due to the cutting blade motor is eliminated.”
