Research Information System
Thesis Type: Postgraduate
Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey
Approval Date: 2015
Student: ABDULLAH NURİ SOMUNCUOĞLU
Supervisor: TUĞBA SELCEN NAVRUZ
Open Archive Collection: AVESIS Open Access Collection
Abstract:This research aims to develop an autonomous control system of an unmanned ground vehicle by using a battery-powered car and focuses on longitudinal and lateral control of the car with fuzzy logic. Fuzzy control rules are derived by modelling a man's driving actions. Experiments are performed using the battery-powered car equipped with sensing devices and a microcontroller. The vehicle is a common battery-powered car, provided with automatic actuators operating on the car controls: steering & accelerator. These actuators are commanded by a fuzzy logic based control system. The input information of the control system comes from ultrasonic distance sensors, tachometer and the pot connected to the steering wheel. The speeds of electric motors are controlled by PWM signals. The desired position of the steering wheel is achieved by a servo motor mounted to the steering shaft with appropriate rate gears. The environment information is taken by ultrasonic sensors, and the velocity information is derived from encoder located on right rear wheel. Longitudinal and lateral motions are run by actuators controlled by a microcontroller. In order to show the vehicle's ability to go through the straight and circular tracks, outdoor tests have been performed. During the tests, the vehicle's ability to accelerate in the straight track, and to slow down when any obstacle was sensed and finally to stop when the obstacle came close to it, is clearly established. In the circular track the vehicle managed to keep the track with a certain distance to the right side of the track. The distance, velocity, and the steering angular position data coming from sensors, encoder, potentiometer, and, PWM signals generated by the system for longitudinal and lateral control, are comparatively investigated in the series of tests. It is found that, the PWM signal which provides longitudinal control and distance data that is coming from front sensor and the PWM signal which provides lateral control, and distance information coming from right sensor and angular position data that is coming from potentiometer are both compatible. As a result, the control architecture was tested at different vehicle speeds. Successful results were obtained after many experiments.