Modeling And Control Of A Continuum Delta Robot

Due to the low efficiency,low accuracy,high labor costs and limited workplace,traditional manual sorting methods cannot meet the increasing demand of pick-and-place tasks in industrial production.In recent years,with the rapid development of robotic technology,many pick-and-place robots have been developed and deployed to various scenarios to implement high-speed and accurate sorting operations.These robots typically adopt rigid-linked serial or parallel structures,and possess disadvantages such as low-safety and small workspace.The precision and cost might be excessive for pick-and-place tasks with medium load and speed requirements.Hence,it's of great significance to design a pick-and-place robot with low cost and high safety for these tasks.Based on continuum mechanism which has been studied comprehensively in recent years,a novel type of parallel Continuum Delta Robot has been proposed,which is aiming at addressing the conventional rigid-linked pick-and-place robots' problems(e.g.,low-safety and high cost)and continuum robots' drawbacks(e.g.,low-stiffness and low-accuracy).The main research contents of this thesis include:Firstly,considering the flexible continuum mechanism,the Cosserat Rod theory was adopted as the tool for mechanics modeling,and an introduction to the theory is presented.Secondly,a compliant mechanism,the dual-continuum-joint translator,was proposed.Its primary mobility is translation.The Cosserat Rod theory was used to establish its kinetostatic model.Based on the model,the deflected shapes and compliance matrices of the translator under different wrenches were calculated,and the primary mobility is quantified.This chapter proves theoretically that the translator's primary mobility is translation and the deflected shapes are close to circular arcs.Next,a parallel continuum delta robot using the dual-continuum-joint translator as its kinematic chain was proposed.The parallel robot's kinematic model was derived initially based on constant curvature bending assumption.Further,with regard to the non-circular deflected shapes of the robot's translator,mechanics model for the translator and the parallel robot was established to increase the position accuracy of the parallel robot.Finally,the upper-level and lower-level control,as well as the communication systems was developed.A series of experiments were conducted on the physical prototype of the parallel Continuum Delta Robot to validate its function.