Research On The Trajectory Planning And Control Of A Hopping Robot

Hopping robot with the advantages of high kinetic dexterity and environmental adaptability can be widely applied to the complex and rough ground environment, such as the archaeological exploration, interstellar exploration, military reconnaissance, geological prospecting, forest protection, rescue and counter-terrorism relief etc. In recent 30 years, the research on hopping robot is mostly concentrated in the legged-hopping robot. This kind of hopping robot has the advantage of high Bionic and dexterity, but its highly nonlinear and strong coupling characteristics increase the difficulty of motion analysis and control.In this dissertation, the hopping robot is seen as a plane redundant robot. The kinematics and dynamic characteristics are analyzed by phases. The floating base model of hopping robot has been established by introducing the virtual passive joint. The unified dynamics equation of hopping robot including flight phase and stance phase has been achieved using Lagrange method based on the floating base, and the phases are distinguished by the difference of constraint. At the same time, the judging condition for the takeoff of hopping robot has been presented.According to the requirement of task space in takeoff phase and landing phase, using the variable parameter quintic polynomial the trajectory planning of hopping robot in task space has been worked. Using the Gradient Projection Method the trajectory of joint space has been computed, and the trajectory optimization has also been worked.After analyzing the underactuated characteristics of hopping robot in flying phase, the equivalent full-drive model of hopping robot has been developed. Using the Gradient Projection Method, the actuate joint trajectory has been computed. According to the problem of that the dynamic singularity is easily appeared during the computation, a discussion has been developed.By the comprehensive use of MATLAB/Simulink and MATLAB/SimMechanics simulation platform, the controller model and mechanics model of hopping robot are established, and the simulation of trajectory tracking in the joint space has been worked.Using the floating base model, the state space model of hopping robot has been developed. By design the reaching law, the silding mode controller has been designed in then task space, which can control the trajectory in task space directly. The control algorithm has been examined by the simulation in MATLAB/Simulink an MATLAB/SimMechanics.The study of this dissertation provides some reference value for the modeling, trajectory planning and control of hopping robot.