Research On The Motion Planning Of The Manipulator Of Automatic Colony Culture And Counting Workstation

With the rapid development of Chinese economy in recent decades,people pay more and more attention to food safety.In the supervision and inspection of food hygiene,the degree of contamination or safety of test samples is reflected by the total number of bacterial colonies.At present,there is an urgent need for a kind of laboratory equipment which combines the function of bacterial culture and colony counting in the field of quarantine and detection,so that robots can replace people to carry out the work of bacterial culture and counting and improve the work efficiency through the intelligent system.In this thesis,petri dish grasping manipulator in the self-developed automatic colony culture counting workstation is taken as the research object,and the collision free path planning algorithm based on the improved RRT algorithm and the time optimal trajectory planning algorithm based on the GWO(gray wolf algorithm)are studied.The design scheme of automatic colony culture counting workstation is introduced in this thesis,the task of petri dish grasping manipulator is clarified,the principle of kinematics is explained,and the mathematical model of the manipulator is established by using MOD-DH method.The forward kinematics equation of the manipulator is derived by using the homogeneous transformation matrix,and the spatial projection method and ZYZ euler angle method are combined to solve the inverse kinematics problem of the manipulator.MATLAB is used to verify the correctness of the positive and inverse kinematics equation of the manipulator,and Monte Carlo method is used to calculate the workspace of the manipulator.Aiming at the problem of collision detection between the path planning of the manipulator and the incubator,the collision possibility of the manipulator is analyzed firstly,and the collision detection algorithm based on hierarchical bounding box is selected to detect the collision between the manipulator and obstacle,so as to improve the algorithm efficiency.It provides a theoretical basis for the collision-free work path planning of petri dish grasping manipulator.In view of the problem of collision-free work path planning,RRT algorithm is selected to plan the working path of the manipulator.In addition,the target bias sampling function and path evaluation function are used to increase the performance of path planning because of the shortcomings of traditional RRT algorithm.MATLAB can be used for the path planning simulation with orientation constraint,and the simulation results show that the improved RRT algorithm is feasible in the path planning of petri dish grasping manipulator.To solve the problem of obstacle avoidance path points,a time optimal cubic B-spline trajectory planning method based on gray wolf algorithm is proposed,and gray wolf algorithm optimizes every time interval.MATLAB simulates the optimal time trajectory planning of each joint of the manipulator,and the simulation results proves the effectiveness of the trajectory optimization method in the trajectory planning of the manipulator.