Comprehensive Research On Passive Dynamics Motion Of Bionic Mechanical Systems

Bionic mechanical systems can adapt to environment of the future world that is unstructured and unknown, and they can lead the trend of the future robotics. One-legged bionic robot is an important branch of bionic mechanical systems, and they have strong capacity to adapt to the environment. To improve the movement efficiency of bionic mechanical systems, and explore design methods and principles about bionic mechanical systems of efficiency and dexterity, one-legged bionic robot is subject to comprehensive research on passive dynamics motion of the system.Base on SLIP-modeled robot, articulated model of one-legged bionic robot in accordance with the physical structure of organisms is established. Then, mathematical model of the system is established according to Lagrange method, Kinetic-energy theorem and Momentum theorem etc. Simulation verification is done, and the simulation results verify correctness of the model. That is theoretical basis for research on dynamics motion of the system.The paper proposes complete numerical algorithm to research on passive dynamics motion of bionic mechanical systems. As effectiveness of the algorithm is influenced by the initial state of the motion, optimization algorithm for the initial state based on Genetic Algorithm (GA) is used in the first, and the optimal initial state of periodic motion is searched taking minimum energy-loss as objective. Secondly, dynamic equations are converted to algebraic equations by Poincare Section method. At last, search algorithm of fixed point based on Newton-Raphson Algorithm is used to search passive dynamics periodic trajectory, and the fixed point of Poincare Section is searched to search Limit Cycles of the system about passive periodic motion.The numerical algorithm is applied to research on passive dynamics motion of the one-legged bionic robot. The paper has obtained Poincare Section's fixed point by solving equation and realized passive dynamics periodic motion planning. That greatly improve the energy efficiency of movement about the system, and the result may be direct reference for designing related controller.