Quadruped Bionic Robot Gait Control And Analysis On Transition Strategy

Legged robots differ from the wheeled robots and tracked robots which are designed according to the structure of the biological animal, the discrete footprints make them be better adaptability to terrain. In the legged robots, the quadruped robots with a moderate number of legs have good movement performance and high load capacity, so they have bright application prospect. This paper’s research object is a bionic quadruped robot, and we focus on the gaits control and gait transitions of quadruped robot.Quadruped bionic robot’s movement modeled on quadruped animal, thus has formed a variety of gait motion. The gaits of a quadruped robot according to the speed since the smallest, in turn, is the walking gait, trot gait, pace gait, bound gait and gallop gait. The current domestic research on quadruped robot gait is almost limited to the walking gait which is enable body in a statically stable and trot gait which is a kind of dynamical gait, less research on other dynamical gaits. In addition, the above gaits studies aim to make robots move steadily in a particular gait, and less solves the transition problem involving different gaits. The purpose of this article is to control a quadruped bionic robot achieve several gaits including walking gait, trot gait, pace gait, and bound gait, and analyze the gait transition in the process of accelerate and decelerate.This paper references the gait pattern of quadruped creature and identifies the order and the law of quadruped bionic robot, and then based on the mechanical characteristics of the quadruped robot analysis the positive and inverse kinematics of the support leg and flight leg separately to find the relationship between the body movement and joint movement, finally based on the virtual leg techniques and SLIP model, a simplified dynamic analysis model is established, and then analysis the dynamic characteristics by using Lagrange dynamics equation to get the relationship between force and motion of the system.Secondly, based on the above work, we get the control parameters of the robot gait by using the control method of the three-variables method, and after the gait generation, robot’s attitude angle is under control by adjusting the force and moment of the system, finally in ADAMS_SIMULINK simulation platform we realize several continuous and stable gait motion.Finally, on the basis of a variety of gait generation, based on bionics principle, we switch gaits by adjusting the robot’s leg movement phase, when the speed is between the common speed range of the initial gait and target gait. According to the direction of the gaits transition, we divide gait transition into two kinds: slow-speed gait to high-speed gait and the opposite direction, then analyze how the key gait parameters affect these two gait transition process respectively. In the end, in Adams_Simulink simulation platform we achieve the gait switching process of quadruped bionic robot.