Study On Stability And Control Strategy For Planar Point Contact Biped Running

For the humanoid robot's potential application, related researches have aroused much attention since its appearance. For more than forty years, research on humanoid robot has acquired remarkable achievements. But to the developmental level of humanoid technology, it is far from the expectation of human being. One of the critical reasons is that movement capability of current humanoid robots is very poor, and the biped moving is slow, inefficient and unadaptable and so on. So, point contact biped robot is brought forward as a new robot system for researching high speed and efficient dynamic moving. Compared with humanoid robot, point contact biped robot has no soles and touches ground with points. The greatest merit is that the point contact biped robot can move naturally with high speed and high efficiency and adaptable. Therefore, the appearance of point contact biped robot offers new methods for humanoid motion planning and control.The key of this dissertation covers the stability and the control strategy of point contact biped robot running, and the content are as follows:As the basis of research on point contact biped robot control, the control system model has been built. Several models are built respectively: kinematics model by D-H reference frame, control system model of single-supporting and flying by Lagrange function, and states-switching model by rigid impact course. All these models will be used for later research.Stability control is a difficulty in point contact biped robot control. For its special configuration, the current stability criterion for humanoid robot can not be directly used on. After much introduction about current stability criterions for point contact biped robot, we know their shortage. So we do research on human running pattern by bionics, and conclude the characters and obtain a description for running stability.The control strategy for point contact biped robot running is the most important goal in this dissertation. By simplifying point contact biped robot as a telescope inverted pendulum, decomposed control strategy can be deducted from bionic research on human running pattern. Running motion is decomposed into three parts as vertical speed, forward speed and body posture independently by decomposed control strategy. Five-link model runs well under the control strategy with a little modification.In order to validate the description for running stability and control strategy, a simulation platform is built. With it, the model of the planar point contact biped robot is built and it runs well under the control strategy.Finally, the main contents of this dissertation are summarized and key points for future research are discussed.