A Rubbertuator-based structure-climbing inspection robot

1 Abstract We describe the design and control of ROBIN a ROBotic INspector. ROBIN is a structure-climbing robot designed for man-made environments. It is intended to carry cameras and other sensors onto man-made structures such as bridges, buildings, aircraft and ships for inspection. The robot has two vacuum xtures connected by a 4 degree-of-freedom articulated mechanism that together allow it to walk across surfaces and transition between adjacent surfaces. ROBIN is novel in several areas. It is the only climbing robot that uses McKibben type pneumatic muscles for motion. It is also novel in its use of a subsumption architecture controller for climbing. ROBIN is one of the few climbing robots that is capable of transitions between surfaces and is one of two robot designs capable of transitioning from a horizontal surface to a vertical surface below. 2 Introduction ROBIN, shown in Figure 1, was developed to be a multipurpose structural inspection vehicle that is specialized for man-made environments. It is eventually intended to be the basic component of a larger structural inspection system. As the infrastructures of many nations age, inspection and maintenance of large man-made structures will become increasingly important. This robot and many other climbing robots will become the tools used to safely and eeciently inspect aging infrastructure, such as buildings, bridges, aircraft and ships. An inspection robot is most useful when it can carry sensors into inaccessible or hazardous areas, thereby making the task safer for human inspectors. An inspection robot is also desirable when it performs tests that are too diicult or tedious for human inspectors to handle 1]. The ability to transition between adjoining surfaces is crucial if a structure-climbing robot is to be used to climb complex structures such as bridges or aircraft. Also, it is important for climbing robots to be able to handle a variety of Figure 1: ROBIN surface types with or without handholds for the robot to use. This allows the robot to be a multi-purpouse inspection vehicle. The rst developed wall-climbers were planar robots, with minimal range of motion in a third dimension. These robots were connned to move on a planar surface and most of the designs are connned to move on a perfectly at plane. This critical limitation prevents these robots from being used in all but the simplest environments, where transitions between surfaces are not required and there are no obstacles on the surfaces. The …