The Motion Trajectory Planning Of Delta Robot For Pick And Place Operation

Driven by factors such as industrial transformation and increased labor costs,the practical benefits brought by industrial robots in various types of production operations have become increasingly prominent.The theoretical analysis and technical application of parallel robots have become the focus of research in the field of industrial robots in many economic entities,and it play a key supporting role in the energy-saving and high efficiency intelligent manufacturing system.In the background of digital manufacturing,the efficiency and stability of the Delta robot's routine operation under the condition of high speed and light load are highly demanded.Therefore,the planning and design of the motion track of the Delta robot end effector in pick-and-place operation is particularly important.Analyze the development of industrial robots and the basic theory of kinematics and dynamics of parallel mechanisms.From the geometric level the end trajectory of Delta robot is planned and designed based on kinematics.Starting from the structural characteristic of the robot,the degree of freedom of the robot is explored and the global coordinate system is established.Inverse kinematics solution based on the vector relationship of the main components of the robot,and the forward kinematics solution is solved by the spatial relationship of the components.Analyze the relationship between the position state of multiple closed-loop motion branches and the singular configuration of the robot,solves the working area of the Delta robot and calculates the motion boundary of the end effector with an example.Investigate the source and type of dynamic and static errors of Delta robots,and construct accurate kinematic models that consider key factors such as assembly error and machining error.Design the motion trajectory of the Delta robot end effector.Starting from the two levels of requirements of the trajectory design and path planning of the Delta robot,reducing the single motion cycle and inhibiting the vibration of the mechanism as the planning goal,choice the robot performance as limiting conditions.The position of the end of the robot in the global coordinate system is introduced into the inverse kinematics model.After obtaining multiple drive joint angle changes,motion planning is performed in the joint space.Combining with the 4-3-4 multi-segment polynomial and 5-3-5 multi-segment polynomial functions to design the angle variation law of the driving joint.The above-mentioned planning objectives,performance constraints and angle variation law are normalized to construct a multi-objective and multi-constraint nonlinear mathematical model,in order to realize the high-speed and smoothness of the Delta parallel robot in the pick-and-place operation.Reconstructing the main steps in the standard Gravity search algorithm: specific redesign of multiple key processes and core parameters such as individual selection in the initial population,control of changes in the gravitational constant G,and processing of individuals beyond the limits.In MATLAB software,the algorithm before and after reconstruction is used to solve the problem of motion trajectory planning.The results show that the CPM(Cycles per minute)of the 4-3-4,5-3-5 multi-segment polynomial velocity planning under the reconstruction algorithm is increased by 3.6%,3.1% compared with the standard algorithm;4-3-4 multi-segment polynomial velocity planning before and after the algorithm reconstruction CPM mean value is respectively 1.9%,2.4% higher than the 5-3-5 multi-segment polynomial.The rationality of the motion trajectory model in the operation cycle and mechanism vibration control and the effectiveness of the reconstructed gravity search algorithm in terms of convergence speed and optimization efficiency are verified.