The theme of the thesis includes the presentation of the idea, of a new way to navigate a robotic lawn mower and also a way to build a prototype vehicle that will allow the realization of this idea in practice. Navigation within the meaning of finding the optimal mowing path and detect possible obstacles on the way, to be as autonomous as possible, while remaining energy efficient.
To design and build such a vehicle requires the integration of different sensors.
Border wire around the lawn, that defines the area to be mowed is connected to a frequency generator (41 kHz) and detected by magnetic field sensor. For uncut grass the photo interrupter sensor is used, and for possible obstacles the ultrasonic range finder.
All of the above is powered by Li-ion battery. The need for different regulated voltage levels (9 V, 5 V in 3.3V) is satisfied by three switching voltage regulators.
All the sensors and the two-wheeled differential drive are controlled by microcontroller of ARM7 series (LPC2138). Algorithms for steering, based on data collected by sensors are described.
Electrical circuit connecting all these parts together, enabling them to function, is presented and analyzed.
Prototype vehicle is built without blades and successfully tested in practice…