The ability to develop a gait with one or more legs missing is an important issue for multi-legged robots used in demining applications. Accordingly, we present a three-legged gait under the assumption that one leg of a quadruped walking robot is missing. After outlining a posture classification scheme for three-legged walking, the kick-and-swing gait is proposed as a basic and reasonable gait for three-legged walking and analyzed using a simple dynamic model. Minimum energy gait planning and an active shock-absorbing method are also investigated. The validity of the proposed gait is shown based on experiments using the quadruped walking robot TITAN VIII.
This study presents a novel bio-mimetic quadruped walking robot with a waist joint, which connects the front and the rear parts of the body. The new robot, called ELIRO-1(Eating LIzard RObot version 1), can bend its body while the legs are transferred, thereby increasing the stride and speed of the robot. The waist-jointed walking robot can move easily from side to side, which is an important feature to guarantee a larger gait stability margin than that of a conventional single rigid-body walking robot. We design the mechanical structure of the robot, which is small and light to have high movability and high degree of human friendship. In this study, we describe characteristics of the waist joint and leg mechanism as well as the analysis using ADAMS to select appropriate actuators. In addition, a hardware and software of the controller of ELIRO-1 are described.
This study introduces a new entertainment robot called ELIRO-II(Eating LIzard RObot version 2)which is a bio-mimetic quadruped walking robot with autonomous eating function. We focus on the realization of the behavior of an animal, i.e., wandering around to find food and eating food. The ELIRO-II is modeled after a lizard, which has four legs, 2-DOF waist-joint, an eye part, a mouth part and a stomach part. The effectiveness of the developed robot is shown through real experiments.
This study presents a small-sized dynmaic walking quadruped robot that uses SMA actuators. Conventional dynamic walking robots have a bulky body and are usually driven by large and heavy electrical motors or hydraulic actuators in order to produce a high output torque. Thus, to resolve this problem, a new SMA actuator is proposed with attractive features, such as a high power density, small size, and light weight. To improve the small ratio of deformation and slow response time of an SMA, the proposed actuator also has a unique winding structure for the SMA wire and reversed gear mechanism. As such, a quadruped robot for dynamic walking is introduced that is equipped with twelve
SMA actuators, four 3-DOF leg mechanisms, and a rigid body. The control system for the proposed robot consists of a main control board, PWM generator board, SMA driver board, and sensor interface board.