Optimal Trajectory Planning Of Citrus Picking Mechanical Arm Based On Fuzzy Genetic Algorithm

Citrus is one of the fruits cultivated on a large scale in China,and it is also the main fruit crop in the world.However,at present,the automation level of citrus picking is relatively low,mainly manual picking.There are problems such as lack of labor resources,timeliness of picking,low picking efficiency and high picking cost.In this situation,intelligent and efficient citrus picking robot came into being.The mechanical arm is the main actuator of citrus picking robot.The trajectory planning of each joint has an important influence on the fast and smooth operation of the mechanical arm.Proper trajectory planning can improve the operating efficiency of the mechanical arm,on the other hand,its operating stability and accuracy can be improved.For this reason,taking time optimization as the goal,the trajectory planning is carried out by using quintic polynomial interpolation function,and the movement trajectory of each joint is optimized through fuzzy genetic algorithm.The main works of this paper are as follows:(1)Establishment of citrus picking mechanical arm model: Taking the steering gear mechanical arm as the research object,the forward kinematic equation is established according to kinematic theoretical knowledge and D-H parameters.Moreover,the inverse kinematics analysis is carried out,and the detailed derivation steps are given.Then the mutual transformation of the mechanical arm’s end position between cartesian space and joint space can be realized.(2)Specific analysis of optimal trajectory planning: Firstly,the realization process of quintic polynomial interpolation function for trajectory planning is deeply analyzed.Then,the actual trajectory planning problem is expressed by mathematical model,and the kinematics constraints are considered.Finally,the influence of genetic operators in the genetic algorithm on the entire evolution process is analyzed.Fuzzy control idea is introduced into the genetic algorithm,so as to dynamically adjust the cross probability and mutation probability.Furthermore,the fuzzy genetic algorithm is used to solve the trajectory optimization problem of citrus picking mechanical arm with the goal of time optimization.(3)MATLAB simulation and analysis of trajectory optimization: For several set path points,combined the optimization algorithm,the joints of the mechanical arm are simulated by MATLAB.The trajectory curves after optimization are drawn and compared with those before optimization.The validity of the proposed algorithm is verified.Finally,the Robotics Toolbox module in MATLAB is used to build the mechanical arm model to complete the movement trajectory simulation of the mechanical arm in cartesian space.