Armless Climbing and Walking in Robotics

Climbing and walking robots perform tasks that are too difficult, dangerous or time consuming for the human worker. These tasks can be inspection work in hazardous or unpleasant environments (Briones et al., 1994) and, (Xu & Ma, 2002), military, maintenance (Tokioka & Sakai, 1988), overhauling (Yanzeng et al., 1999), manufacturing (Shuliang et al., 2000), and search and rescue works. With all progress in the development of climbing and walking techniques such robots still haven’t been able to penetrate the service market. There are two reasons for this slow down: First, most of today’s commercially available climbing and walking robots have insufficient payload-to weight ratio. Second, all of the most recent developments have been engineered for one very specific task. But the customer demand new approach in robot development. Mainly such robots must be competitive with other solutions by conducting the task economically. Moreover the climbing and walking robots should also be able to perform a variety of tasks so that the return of investment for the customer is improved. Armless robot without articulated hand or legs requires holding technique to working surfaces. Several types of attachment mechanisms have been studied and developed for climbing and walking robots. In the case of workspace that contains structural elements that support the use of mechanical fasteners or grippers then the contact to the surface can be established through a positive connection. This type of adhesion mechanism is the grasping technique, which requires holds, spines or grooves to grasp and pull the whole body upwards, however the climbing down process is challenging for this method (Bretl et al., 2003) and, (Autumn et al., 2000). For rough surfaces, this is a quite powerful technique but it is not suitable for armless robot. In addition if the surface is flat and smooth, this method cannot be applied. Most of today‘s robotic applications demand highly flexible solutions able to move the robot autonomously without the need of grasping a predefined elements. Therefore, the states of the art of armless robots developed an adhesive force method for climbing surfaces. Such force can be generated using different tactics. The most common type is the suction adhesion, where the robot carries an on-board pump to create vacuum inside cups which are pressed against the wall or ceiling (Pack et al., 1997) and, (Nagakubo et al., 1994). Such attachment suffers from the time delay in developing the vacuum and the special requirements for smooth surfaces and sealing design. In addition, power consumption is too high during attachment. Finally, the suction adhesion mechanism relies on ambient pressure to stick on wall, and therefore it is not useful in applications that require near zero surrounding pressure as in the case of space application. O pe n A cc es s D at ab as e w w w .ite ch on lin e. co m