Rough Terrain Hybrid Mobile Robot

1. Research Topic



With the advancement of robot technology, robots are no longer confined to only one place, but need to move to many places to do work. In this sense, the mobility of a robot that determines whether a robot can travel on different kinds of terrains has become increasingly important. Although robots should be able to move around freely, it is also crucial that it does not overturn while traveling, and therefore, stability has also become an equally important issue. In this research, new mobile mechanism which can overcome rough terrain with high stability was developed.


2. Research Contents



The new mobile mechanism named “Rocker Pillar” was developed. The rocker pillar can overcome rough terrain with high stability by using the rocker bogie mechanism and active caterpillar mechanism on the robot.
 

A. rocker bogie mechanism

The Rocker-Pillar is composed of two caterpillars, four wheels, a pair of two passive joints and the main body. Its linkage mechanism is the same as the Rocker-Bogie mechanism, which makes every wheel contact the ground by use of passive joints without any actuators. When the robot is traveling at high speeds on rugged terrains, the caterpillar robot transmits much vibration to the robot body, and as a result, the main body is at risk of being overturned. The wheels and the linkage mechanism can reduce the risk of such an overturn. By using the Rocker-Bogie mechanism as a linkage system, the robot can stabilize its main body at it travels on rugged terrains.
 

B. active caterpillar mechanism

Instead of six wheels as in a Rocker-Bogie mechanism, the Rocker-Pillar has two caterpillars on the front and two wheels in the middle and two wheels at the back. The two caterpillars can change the angles with the linkage. Therefore, the Rocker-Pillar can overcome the rough terrains that the wheel mechanism cannot by using active caterpillars.

   

Depending on the shape of terrain, the Rocker-Pillar changes its mode to fit to the terrain. On rugged terrains that give rise to a large amount of vibration, the Rocker-Pillar lifts up its caterpillars upward and changes the mode to the Rocker-Bogie mode. The caterpillars contact the ground not on a surface but in a line and act as wheels; essentially, the Rocker-Pillar contacts the ground with six wheels like a Rocker-Bogie, and the linkage mechanism maintains its stability on rugged terrains. Also, the Rocker-Pillar can change its mode to the caterpillar mode so that it can overcome terrains that the wheel mechanism cannot. Holes are one of the terrains that previous models were not able to overcome. Wheels cannot pass over holes that are larger than the diameter of the wheels. However, by orienting the caterpillar tracks backward, the caterpillar and the wheel in the middle form a large caterpillar. By using the caterpillar mode, the Rocker-Pillar can overcome terrains that the wheel mechanism cannot overcome.

                           

           < Prototype #1 The Rocker pillar >                    < Prototype #2 The Rocker pillar2 >


3. Publication



• Dongkyu Choi, Jongkyun Oh, Jongwon Kim "Analysis method of climbing stairs with the rocker-bogie mechanism" JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY272783-2788  2013 [PDF]

• 최동규, 정승민, 김종원 "험한 지형 주행 운반 로봇 플랫폼의 개념 설계 및 분석" 한국정밀공학회지3024-31  2013 [PDF]

• Dongkyu Choi, Jongkyun Oh, Jongwon Kim "Analysis Method of Climbing Stairs with the Rocker-Bogie Mechanism" KSME272783-2788   [PDF]

• Dongkyu Choi, Seungmin Jung, Jongwon Kim "The Concept Design of the Stable Linkage Mechanism on the Rough Terrain" ICCAS 2013Gwangju  23 20 Oct. [PDF]

• 김영수, 최동규, 김제혁, 김홍민, 김화수, 김종원 "험한 지형에서 본체의 높이 및 피치각 변화가 작은 패시브 서스펜션 주행 메커니즘 개발" 제어로봇시스템학회Daejeon  08 05 2015 [PDF]

• 김영수, 최동규, 김지훈, 김종원 "험지 주행 플랫폼 RHyMo의 설계 및 제작" KROC 2014  21 6. 2014 [PDF]

• 김영수, 최동규, 홍희승, 배장호, 김종원 "험지 주행 로봇의 새로운 흔들림 안정성 기준에 대한 연구" 한국정밀공학회Changwon  31 10 2014 [PDF]

• 최동규, 정승민, 김종원 "트랙 구조를 통한 라커보기 구조의 계단등반 능력 향상" 한국정밀공학회 2013 춘계학술대회Jeju  31 5. 2013 [PDF]

• Dongkyu Choi, Jeong R Kim, Sunme Cho, Seungmin Jung and Jongwon Kim "Rocker-Pillar Design of the Rough Terrain Mobile Robot Platform with Caterpillar Tracks and Rocker Bogie Mechanism" IROS 2012Algarve  12 10 2012 [PDF]

• 최동규, 정승민, 김종원 "라커필러 : 험지 주행 운반 로봇의 설계 및 개발" 한국정밀공학회 2012년도 춘계 학술 대회Jeju  12 2012 [PDF]

• 정승민, 최동규, 김종원 "Quasi static 해석을 통한 라커필러 턱 극복 능력 분석" 한국정밀공학회 2012년도 춘계 학술 대회Jeju  12 2012 [PDF]

• 최동규, 이석우, 장도영, 김남수, 홍희승, 김종원 "라커보기와 캐터필러를 이용한 주행 메커니즘 개발" 한국정밀공학회 2011 춘계학술대회   [PDF]

• 김종원, 최동규, 장도영, 김정률, 오종균, 이석우 "캐터필러와 주행휠을 구비한 이동로봇" 10-2012-0005613  


4. Researcher



Ph.D : Dongkyu Choi
M. S :  Seungmin Jung