Fetching Theoretical Analysis And Experimental Research On The Underreacting ET Robot

With the development of human society and the improvement of industrial automation,robots have played an increasingly important role in many aspects of production and human life.At the same time,robots that worked in unstructured environment have gradually become the focus of many scholars.The traditional discrete robots have many advantages such as high efficiency,precision and strong carrying capacity in the structured environment.However,the unstructured environment can not meet the requirements of automatically adapting to the target object and the operation has more restrictions.In recent years,a batch of adaptive robots designed according to bionics have emerged.Such robots can be adaptively operated according to the shape of an object to be held.However,there are some problems with such robots what limited their scope of application.For example,most of these robots are driven by flexible materials and equipped with multiple driving sources for movement.This has led these robots difficult to build a mathematical model of the system and can not meet the requirements of certain special environments such as high temperature and vacuum.In order to solve the shortcomings of those robots,our research group introduced the concept of under-actuated design and designed an underactuated ET robot based the on scissors mechanism.The robot is driven by only one motor and can automatically adapt to the shape of the target object for gripping action.On the basis of deep research on the process of robotic grasping,this paper simplifies the structural model of the underactuated ET robot,and proposes a simplified model of the robot's dynamic model for dynamic simulation analysis.Based on the simplified model,the kinematics of robots in grasping objects and encountering obstacles are analyzed in depth and a mathematical model describing the variation of grasping force during robot grasping is proposed.The main research work carried out in this paper is as follows:First of all,based on the deep research of the structure and movement mechanism of the underactuated ET robot,the structure of the robot is simplified appropriately,and greatly reduced the computational complexity of the robot.Then,based on the simplified kinetic model,the ET robot's catching process and the movement process after obstacles are deeply studied.The static contact force and the virtual work principle are used to deduce the joint contact force and the change of the driving force of the robot during the movement of the robot after encountering the obstacle,a mathematical model is established and the simulation is carried out.Finally,an experimental platform of the underactuated ET robot was built,and the mathematical model proposed was validated experimentally.