Research On Obstacle Properties Of Small Robot Based On Abnormal Wheels

Mobile robot applied in fields like military reconnaissance, disaster rescue, fire EOD, agricultural monitoring, lunar exploration etc, gradually become the trend. The environment of these special areas are mostly complex terrain of non-regular, such as wild jungle, ruins after the earthquake, the building after fire, rugged mountains, the bumpy surface of the moon etc, so studying on obstacle manner and the ability become one direction of many scholars’interests. Small robots are always used in the special areas, needing small size and light weight, has a certain capacity, environmental adaptability and high mobility. Miniaturization and obstacle ability belong to a contradiction. In this paper, considering of getting both the mobile efficiency and obstacle ability, we put forward a kind of small robot model based on abnormal wheels, which is quadruped eccentric wheel-legged robot. The robot has the same efficiency compared with a wheeled robot and high obstacle crossing ability independently.Features of normal wheels are analyzed in the beginning of this paper. After compared the two possible improved results, we choose the eccentric wheel as the walking unit, make four eccentric wheels as a group and make into robot. Then we design gaits for the robot. In the second part of the paper, we analyze the robot structure by kinematics and dynamics methods, find the law of motion of eccentric wheel and construct a reference coordinate system to analyze the state of robot’s movement in the kinematics part. Assuming the robot’s weight evenly distributed in each of the eccentric pivot point, we describe the force state of eccentric wheel and analyze the dynamics state of the whole organism. The third part of this paper, compared with the ordinary wheeled robot, we describe the obstacle-crossing course and principle of the quadruped eccentric wheel-legged robot and get the obstacle-crossing capability under various environmental obstacles through theoretical calculation. The obstacle environment is divided into four typical species, which are slope, single step, convex object and small gully. The last part, we do a lot of experiments to verify the obstacle-crossing principle and test the obstacle-crossing performance. Then the reasons why existing difference between experimental results and theoretical model was analyzed at last.Through theoretical analysis and experimental study of this subject, quadruped eccentric wheel-legged robot is proved that has both walking efficiency and obstacle-crossing ability advantages. Simultaneously the robot has simple structure and can be easily controlled on the control system level. Rescue workers can carry the robot to the complex terrain after disaster. Actually the robot can cross the obstacle height much larger than the radius of a wheel.