Obstacle Avoidance Path Planning Of Tung Oil Fruits Harvesting Manipulator Based On C-Space

With the progress of technology and the change of forestry work mode,it is an essential trend to develop the multifunctional technique equipment which is combined with intensive fostering collection and cutting.As a product of the development of modern science and technology,the manipulator which is widely used in various production and life field will be the nueleus of forestry equip consequentially.Then,obstacles existence of working environment seriously restrict the application and development of manipulator.So this paper reserch the problem of obstacle avoidance and path planning of manipulator.It has the important practical significance to broaden the scope of application and improve the production capacity of manipulator.Certainly,this paper mainly research from the the following three aspects.Establishment of mechanical physical and mathematical model,and analysis of kinematics.In this paper characteristics of tung oil fruit picking manipulator physical model analysed deeply.And the mathematical model is described through D-H method based on the physical model.The forward and inverse kinematics equation is derived on the basis of kinematics mathematical model.And simulation analysis on the manipulator verify the correctness of the mathematical model and the manipulator kinematics equation through improvement of MATLAB/Robotics toolbox toolbox.Design of obstacle avoidance path planning algorithm.This paper ultimately selected the free space method based on C-space(Configuration Space)as a method of manipulator for obstacle avoidance and path planning through the comparison of advantages and disadvantages of several commonly used algorithm for obstacle avoidance and path planning.By analyzing the structure characteristics of picking manipulator,picking work environment characteristics of tung oil fruit and the implementation method of the picking arm the paper put forward to the joint1 and joint 4 as the role of obstacle avoidance joint in picking process of tung oil fruit.And the paper design the main steps of tung oil fruit based obstacle avoidance and path planning algorithm based on that.The C-space information description and the using of search algorithm.Fristly,the paper makes us understand the definition and properties of the C-space obstacles.Secendly,the establishment of mathematical model of C-spatial obstacle about the point,line,circle as the basic elements of the C-spatial obstacle is necessary.And the paper derive the boundary function for description of C-space obstacles through the geometric analysis method.Thirdly,this determines grid method to describ the C-space information.And this makes C-space obstacles describing by use of the boundary function transform C-space obstacles describing by use of the grid method.Fourthly,the paper builds a gridding C-space model by use of MATLAB.Subsequently,this paper figure out a no collision path connecting the start point and end point in figure of gridding C-space model by using of A*algorithm through comprehensive analysis of the advantages and disadvantages of various traditional search algorithms and artificial search algorithm.In this paper,through the combination of MATLAB simulation and field tests we have verified the algorithm.Test results show that the method used in this paper,can be fast,effective to plan no collision path under the work environment within obstacles.And the paper achieves the anticipated research goal.