Implementation of Remote Operating Software for a Multi-legged Subsea Robot CR200 providing Soft Real-time Control

Authors
Banghyun Kim, Sung-Woo Park, Pan-Mook Lee, Bong Huan Jun

한국해양과학기술협의회 공동학술대회, 2013, Jeju in Korea

Abstract - This paper introduces romote operation software providing soft real-time control using software timer for a mulit-legged subsea robot, named CR200, which is a 200m-class walking robot. The CR200 can work in shallow and strong tidal current and high turbidity environminet by crawling sea floor using six legs to survey shipwreck and scientific research. Operators control the CR200 using various programs running on computers in the remote control unit. Operation software consists of agent program, pilot program, 3D viewer program, dynamics simulation program, navigation program, video program, scanning sonar program, acoustic camera program, and current monitoring program. Agent program is main program which interfaces remote control unit with the CR200, and calculates joint angle reference of legs by posture and gait algorithm. Agent program should support real-time characteristic because the CR200 needs 100 Hz control frequency to walk naurally. We have implemented soft real-time characteristic using software timer without real-time operating system. By experimental results, average of timer interval is exact 10 ms. Also timing occurrence error is less tha 171 us, and its standard deviation is 10.375 us. These results show that our approach without RTOS is enough to control the CR200 by 100Hz frequency.

(Pressed in Korean)