Pneumatic Actuators for Climbing, Walking and Serpentine Robots

摘要

Pneumatic actuators originally limited to simple motion between two hard stops, are now becoming more and more popular, and substituting in many cases electric drives. Especially robots intended to contact with ground, obstacles, co-operating with other robots and humans require drives strong, compliant and safe. We have shown a few projects of quite different machines, all taking benefits from various pneumatic drives. But this chapter does not cover all important areas of possible applications for pneumatics. Actuators with high power/weight ratio are needed in mechanical systems that support human motion in rehabilitation, welfare, and sports. Moreover, mechanical systems for entertainment requires various, smooth motions. Actuators applied to these systems also should have high power/weight ratio. From biology we know that all animals, try to move in an energy efficient way. The important mechanisms available are muscles and tendons which make energy recuperation possible. For example, the Achilles tendon in a human leg can store up to one third of the motion’s energy during running. The muscular system is capable of adapting stiffness characteristics in order to move in a wide range of different walking and running patterns and still exploit the passive behavior of the actuation system. This is why in the very first jumping robots thrust was generated by pneumatic actuator (Raibert, 1986). In this area we focus our investigations on the aspect of changing mechanical impedance of driving system and its influence on features of a jump (Jezierski & Granosik, 2007). Pneumatic drives can be combined with electric motors like in Distributed Macro Mini (DM2) Actuation concept (Zinn et al., 2004) producing hight performance and low impedance human safe actuator. We also plan to use pneumatic elements for suspension of just beeing designed serpentine robot Wheeeler (Pytasz & Granosik, 2007).