Design Issues and Applications for a Passive-Dynamic Walker

Humanoid and walking robots have been widely developed and their use in human environments is not far out of reach. The main problems in practical applications of machine walking are energy consumption, complex control and design, and high cost. The main feasible indoor application of a walking machine is that of a humanoid robot as a companion, nurse, guide, or information desk or reception clerk. In a smart object system environment, such as a smart house where all objects are interconnected, a humanoid robot can provide services for the centralized host or gateway server of the house. It is a mobile system already equipped with sensors, controllers, manipulators (hands) and a communication system. From the features of humanoid robots and of the smart object systems, a new direction of research could emerge embracing parts of both fields. In the interest of furthering the capabilities of walking robots, we designed an approach to further the capability of walking robots. We built a four-legged passive-dynamic walking machine with its inner and outer legs connected rigidly two by two, making it equivalent to a biped machine in terms of dynamics. We conducted our experiments with two different knee designs. Both mechanisms were designed in an attempt to create a simpler and easier-to-adjust knee-locking mechanism. We conducted a series of experiments in which we counted the steps the walker made while walking down an incline and compared the results achieved with the two different knee-locking mechanisms. We also performed a walking cycle investigation of a person walking casually down the same slope used for the walker experiments, calculated the average time intervals within one cycle and made a comparison between the test subject and our walker.