We developed an omni-directional mobile robot based on StrongARM processor. Robot was constructed with three driven omni-directional wheels arranged in a triangular manner. StrongARM processor was used as main processor in the mobile robot and wireless LAN was used to control and monitor mobile robots without any consoles through ethernet. We used a commercial StrongARM processor board. To control mobile robot based on StrongARM processor, we designed and implemented StrongARM interface board and control task based on Real-time Linux with real-time scheduler, real-time ISR, usabilty all Linux application programs.
Sensor system was designed and implemented on the purpose to apply obstacle-avoidance control of mobile robot. IR ranger was used for near obstacle detection and accelerometer for calculating robot position.
Ultasonic phased array was designed for far obstacle detection and the better performance of beam-directivity. It was composed of 8 sonar sensors in a line. Scanning or focusing is possible while changing of phase difference. So fast-speed scan is possible without moving sonar sensors. From sonar distance measurements, the distance and the direction of the obstacle can be calculated by using 2 sonar receivers.
The results of experiments are descirbed to show moving control of implemented omni-directional mobile robot, and validy of ultrasonic phased array for robot sensing, and autonomous navigation while avoiding obstacles.
