| Fruit harvesting is an important process in agricultural production. To raise labor productivity and working quality, reduce working density, improve working environment and realize harvesting mechanization, automatization and intelligentization, a seven-degree-of freedom tomato harvesting manipulator was designed based on tomato phytological characteristics and cultivating methods. Simultaneously, mechanism analysis and simulation were performed on kinematics and performances of the manipulator.(1) Mechanism type-synthesis and dimension-synthesis of the tomato harvesting manipulator were investigated according to some criteria of tomato physiological characteristics and cultivated methods and type-synthesis regulation. A redundant manipulator consisting of 2 prismatic joints and 5 rotational joints was determined for tomato harvesting. At the same time, a synthetic object function for optimizing design was set up based on workspace and link length. Optimal solutions of the manipulator mechanism structure and motion parameters were obtained. Furthermore, the rational structural parameters of the manipulator were determined according to the practical production environment and working mode.(2) Link coordinates of the manipulator were set up by Denavit-Hartenberg method. Simultaneously, forward kinematics and inverse kinematics was modeled through homogeneous transformation and Jacobian matrix was reached as well, which provided the basis for kinematics analysis, simulation and performance optimization.(3) The wrist workspace (WW), the accessible workspace (AW) and the dexterous workspace (DW) of the manipulator were obtained using the enveloping analytical method, the numerical method and the end link configurations. It was indicated that the WW satisfied the design requirements of the manipulator. The AW expanded with the increasing of the end link and the end-effector length, while the DW and the dexterity of manipulator reduced accordingly. In addition, the length of link 3 and link 5 and the angle range of joint 5 should be chosen reasonably in order to decrease the cavum volume in the workspace.(4) The position workspace of the end-effector was simulated by the Monto Carlo method. It was showed that the position workspace of the end-effector covered the growing range of tomato fruits completely, in which the working points were distributed density and equably and can satisfy the picking requirements.(5) Simulation of forward kinematics and inverse kinematics was performed on the tomato harvesting manipulator simultaneously by MATLAB/SIMULINK. The forward kinematics simulation results showed that accelerates of the end-effector obtained from simulation was equal to that of the given. The relation between the velocity of the end-effector and simulation time was nearly linear with gentle tangent slope, and the position varied with time continuously and smoothly without any vibration during moving. It was observed from the inverse kinematics simulation results that the position, accelerate and velocity minimum-norm solution of joint 1,3,7 of the manipulator were controllable with no abnormal fluctuates, which satisfy the motionrequirements. However, the position, the accelerate and the velocity of joint 2,4,5,6 of the manipulator varied with time irregularly with high efficiency during the simulation time t=4.7197s~5s, which would make the joint uncontrollable and result in the vibration of the manipulator system, hence the kinematic performance of manipulator should be improved.(6) The analysis on Singularity configurations of the manipulator were investigated by the singular value decomposition of Jacobian Matrix, which was treated with the damped least-square method in the motion. From the results obtained it was indicated that the minimum singular value of manipulator calculated by the damping Jacobian matrix were far from zero position. Velocity, position and accelerate of all the joints of manipulator moved regularly, consequently the problem that the joint of mani...
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