翻译部分：英文原文Mobile platform of rocker-type coal mine rescue robotLI Yunwang, GE Shirong, ZHU Hua, FANG Haifang, GAO JinkeSchool of Mechanical and Electrical Engineering, China University of Mining & Technology, Xuzhou 221008, ChinaAbstract: After a coal mine disaster, especially a gas and coal dust explosion, the space-restricted and unstructured underground terrain and explosive gas require coal mine rescue robots with good obstacle surmounting performance and explosion-proof capability. For this type of environment, we designed a mobile platform for a rocker-type coal mine rescue robot with four independent drive wheels. The composi- tion and operational principles of the mobile platform are introduced, we discuss the flameproof design of the rocker assembly, as well as the operational principles and mechanical structure of the bevel gear differ- ential and the main parameters are provided. Motion simulation of the differential function and condition of the robot running on virtual, uneven terrain is carried out with ADAMS. The simulation results show that the differential device can maintain the main body of the robot at an average angle between two rockers. The robot model has good operating performance. Experiments on terrain adaptability and surmounting obstacle performance of the robot proto- type have been carried out. The results indicate that the prototype has good terrain adaptability and strong obstacle-surmounting performance.Keywords: coal mine; rescue robot; rocker suspension; differential; explosion-proof design 1 IntroductionIn the rescue mission of a gas and coal dust explosion, rescuers easily get poisoned in underground coalmines full of toxic gases, such as high-concentration CH4 and CO, if ventilation and protection are not up to snuff. Furthermore, secondary or multiple gas explosions may be caused by extremely unstable gases after such a disaster and may cause casualties among the rescuers1. Therefore, in order to perform rescue missions successfully, in good time and decrease casualties, it is necessary to develop coal mine rescue robots. They are then sent to enter the disaster area instead of rescuers and carry out tasks of environmental detection, searching for wounded miners and victims after the disaster has occurred.The primary task of the robots in rescue work is to enter the disaster area. It is difficult for robots to move into restricted spaces and unstructured underground terrain, so these mobile systems require good obstacle-surmounting performance and motion performance in this rugged environment2. The application of some sensors used for terrain identification are severely restricted by low visibility and surroundings full of explosive gas and dust; hence, a putative mobile system should, as much as possible, be independent from sensing and control systems3.Studies of coal mine rescue robots are just beginning at home and abroad. Most robot prototypes are simple wheel type and track robots. The mine explora- tion robot RATLER, developed by the Intelligent Systems and Robotics Center (ISRC) of Sandia National Laboratories, uses a wheel type mobile system4. The Carnegie Mellon University Robot Research Center developed an autonomous mine exploration robot, called “groundhog”5. Both the mine rescue robot V2 produced by the American Remote Company and the mine search and rescue robot CUMT-1 developed by China University of Mining and Technology, use a two-track fixed type moving system6-7. These four prototypes are severely limited in underground coal mines. Rocker type robots have demonstrated good performance on complex terrain.All three Mars rovers, i.e., Sojourner, Spirit and Opportunity used mobile systems with six independent drive wheels8-9. Rocker-Bogie, developed by the American JPL laboratory has landed successfully on Mars. The SRR robot from the JPL laboratory with four independent drive and steering wheels consists of a moving rocker assembly system, similar to the four wheel-drive SR2 developed by the Univer- sity of Oklahoma, USA10. Both tests and practical experience have shown that this type of system has good motion performance, can adapt passively to uneven terrain, possesses the ability of self adaptation and performs well in surmounting obstacles. Given the unstructured underground terrain environment and an atmosphere of explosive gases, we investigated a coal mine rescue robot with four independent drive wheels and an explosion-proof design, based on a rocker as sembly structure. We introduce the composition and opera- tional principles of this mobile system, discuss the design method of its rocker assembly and differential device and carried out motion simulation of the kinematic performance of the the robot with on ADAMS, a computer software package. In the end, we tested the terrain adaptability and performance of the prototype in surmounting obstacles.2 Mobile platform11-12Of As shown in Fig 1, the mobile platf