Design And Nonlinear Control Of A PMA-driven Bionic Neck Robot With A Spring Spine

As the development of living condition,more service robots will be introduced in our lives in the future.Comparing to the service robots that can only realize the specific functions,the robots with the ability of human-robot communication and expression interaction will be more popular among humans.The realization of these functions can not be separated from the perfect noumenon structure.Bionic Neck Robot(BNR)is a kind of robot that mimics the locomotion and structure of the human neck joint.The human neck is a complex component,which provides dexterous mobility in a very compact and lightweight form and plays a series of functions such as protecting the head,assisting the perception,the body communication and reducing the external shock.It is very difficult for a simple mechanical mechanism to imitate the neck of the human body.Therefore,it is of great significance to study a new type of bionic neck robot.In this paper,a novel PMA(Pneumatic Muscle Actuator)driven bionic neck robot with a spring spine is proposed.This design has a noticeable human similarity.The PMA and the spring connect the moving platform and the robot base platform.The spring works as the cervical spine to support the head and generates desired head movements and as it supports the platform,it can achieve telescopic and flexural motion.The PMAs,like the human muscles can generate linear contract force and drive the robot in all directions.This design makes the neck robot flexible,lightweight,compact,flexible and so on.First of all,we mastered the preparation method of pneumatic muscle actuator,made a new type pneumatic muscle actuator,designed and built the performance test experimental platform of PMA,tested the static performance of the pneumatic muscle,build statics and kinetic models of PMA,and a single pneumatic muscle position servo control strategy based on sliding mode variable structure is proposed,and the effectiveness of the method is tested by simulation experiments;Secondly,according to the data of human body motion,the indexes of neck joint are determined.On this basis,a parallel bionic neck joint mechanism based on pneumatic muscle is designed.And by building the forward and inverse kinematic model,an optimization problem is formulated to find the optimal physical parameters that can meet the given range of motion.A rapid prototyping system was developed.Simulations and experimental results verify the workspace of the robot with optimized parameters.Thirdly,in order to get rid of the limitation of PC and realize the control,perception and drive integration of PMA,an embedded drive controller of PMA is designed and manufactured.The driver controller is divided into three layers:control layer,driver layer and perception layer,the embedded board design adopts hierarchical management,on the one hand to prevent interference,on the other hand,each function board can also be used alone.Its design and use will greatly reduce the volume of the entire mechanism,and make the mechanism wiring more reasonable and beautiful;Finally,the dynamic and the statics model model of the neck joint and the mechanical model of the support spring are established.On this basis,a force-position hybrid control scheme for the 6 degree of freedom neck joint is proposed.The overall hardware scheme design of the control system was completed,and the hardware design of electronic control system and pneumatic loop system were completed according to the overall hardware scheme design.The experimental results are carried out on this basis,and the experimental results verify the effectiveness and accuracy of the proposed algorithm.