Legged locomotion has high mobility on irregular surfaces by touching the ground at discrete points. Inspired by the creature’s legged locomotion, legged robots have been developed to explore unstructured environments. In this paper, we propose a modular crawler that can easily adjust the number of legs for adapting the environment that the robot should move. One module has a pair of legs, so the number of legs can be adjusted by changing the number of modules. All legs are driven by a single driving motor for simple and compact design, so the driving axle of each module is connected by the universal joint. Universal joints between modules enable the body flexion for steering or overcoming higher obstacles. A prototype of crawler with three modules is built and the driving performance and the effect of module lifting on the ability to overcome obstacles are demonstrated by the experiments.

Abstract
1. 서 론
2. 설 계
    2.1 모듈 설계
    2.2 다리 링키지
    2.3 모듈 리프팅 메커니즘
    2.4 방향 전환 메커니즘
    2.5 3개의 모듈로 구성된 크롤러 프로토타입
3. 분 석
    3.1 다리 링키지 궤적
    3.2 모듈 사이 길이에 따른 최대 리프팅 각도
4. 실험 및 결과
    4.1 주행 성능 실험 및 결과
    4.2 장애물 극복 실험 및 결과
5. 결 론
References

• 임소정(Mechanical and Aerospace Engineering, Seoul National University) | Sojung Yim
• 백상민(Mechanical and Aerospace Engineering, Seoul National University) | Sang-Min Baek
• 이종은(Mechanical and Aerospace Engineering, Seoul National University) | Jongeun Lee
• 채수환(Mechanical and Aerospace Engineering, Seoul National University) | Soo-Hwan Chae
• 유재관(Unmanned/Robotic Systems Lab. LIG Nex1, Seongnam) | Jae-Kwan Ryu
• 조용진(Unmanned/Robotic Systems Lab. LIG Nex1, Seongnam) | Yong-Jin Jo
• 조규진(Mechanical and Aerospace Engineering and Institute of Advanced Machines and Design, Seoul National University) | Kyu-Jin Cho Corresponding author