Papers by Author: Hui Ping Shen

Abstract: A novel 1-translation and 2-rotation parallel manipulator is investigated. An analytic solutions corresponding to the forward and inverse position are obtained. The influences by the three input variables on the three output variables are analyzed carefully and the valid working ranges of input and output variables are given. The work of the paper provided a solid foundation for mechanical structural design and real-time controlling of the novel parallel mechanism by structural parameter discussion.

Abstract: This paper addresses geometry design of a new kind of 2-DOF five-bar parallel manipulator actuated by two orthogonal layout linear actuators. Although the manipulator has only one geometric parameter, i.e., the link length, the distribution of performance index is more complex. Here, we propose a design approach utilizing a performance chart and local condition index. The key problem in the design of the manipulator is the determination of not the link length but the workspace satisfying the design index. This paper gives an effective method to obtain the basic good-condition workspace without dimension. Then, based on the optimum non-dimensional result, the optimum dimensional parameters are achieved which is suitable for the desired workspace. The optimum methodology of this paper is convenient and can be extended to other parallel manipulators

Abstract: In this paper, a planar five-bar mechanism driven by two orthogonal layout actuators is proposed. The inverse and forward kinematics can be described in closed form. The Jacobi matrix, singularity and workspace of the mechanism are investigated. In addition, charts of some performance indices, such as dexterity, velocity, payload capability and stiffness index, are plotted. The results show that the mechanism has a flatter singularity-free workspace, which is usually our research object. On the other hand, Dexterity, Payload capability and stiffness index of the mechanism are basically the same distribution on the workspace, which are axis symmetric. But, the trend of velocity index is opposite. The proposed mechanism can be applied to the field of machine tools or used as the mobile base for a spatial manipulator. The results of the paper are very useful for the design and application of the new mechanism

Abstract: In order to meet the needs of changing positions and orientations in large-scale product testing and large workpiece operating, such as machining, welding and spraying, this paper presents a planar decoupled parallel manipulator driven by three sliders. This simple but practical mechanism is capable of realizing a large workspace. The direct and inverse kinematical solutions are derived. The working spaces of the end operator are carried out when it is in given positions and given orientations. The simulation demonstrates that all kinds of straight lines and circles can be realized by the end operator of the mechanism, which the corresponding motion disciplines and characteristics of the three sliders are also obtained. Last, the virtual prototype of the manipulator is given. The paper lays the foundation for the manufacture, the real-time control and industrial application of the 3-DOF parallel manipulator.

Abstract: In this paper, a 2-DOF planar parallel manipulator actuated horizontally by linear actuators is proposed. The inverse and forward kinematics can be described in closed form. The velocity equation, singularity of the manipulator and the conditioning index is investigated. In addition, the inverse dynamics problem of the device is investigated employing the Lagrange approach. The dynamic simulation is carried out. The results show that the kinematics performance and the force transmissibility are worse when the end-effecter moves near the singularity. The proposed manipulator can be applied to the field of machine tools or used as the mobile base for a spatial manipulator. The results of the paper are very useful for the design and application of the new manipulator.

Abstract: Aiming at the helical planetary gear reducer with the small module (m≤0.8mm) and big helical angle (β≥20°) applied widely, a novel method of the design and manufacture is come up. The developed reducer matched with the suitable motor not only reduces output speed and inertia of the motor, but also increases greatly stability of tooth meshing. Thus, it could reduce transmission noise and favorably increase the output torque of the motor. So it has a wide application prospect.

Abstract: A novel 3 degree of freedom(1-Translation and 2-Rotation) parallel mechanisms is investigated. The forward and inverse position of the mechanism are studied. The influences by the three input variables on the three output variables are analyzed carefully and the valid working ranges of input and output variables are given by discussing structural parameter. These provide a solid foundation for selecting structural designs and kinematics parameters accurately and for realizing the control and industrial application of the mechanism.

Abstract: A kind of 2-DOF parallel manipulator driven by two sliders moving along two parallel guides is analyzed. Based on the explicit expression of inverse position, velocity and acceleration analyses, the mobile trajectory of this manipulator is investigated and simulated. In trajectory planning, the trajectory profiles are assigned to be accelerated and decelerated at the first and last few seconds, respectively, and keep at constant speed for the remainder of time, where the forth-order polynomial is fitted during acceleration and deceleration, and clothoid curve is applied around the corner of axis. Then the mobile rule exerted on the actuator sliders is obtained using inverse position based on the desired end-effecter trajectory. Finally, the virtual prototype of this mechanism is modeled using Solidwork and the kinematics and dynamics simulation is performed using Cosmostion. The result shows that both velocity, acceleration of the sliders and the driving force exerted on the sliders are continuous curves, which can fully satisfy the demand of high-accuracy and real-time processing of the high-speed Manipulator.

Abstract: The dynamic characteristics of the parallel mechanism depend strongly on the operating modes corresponding to different inverse solutions, but few of them have been involved with. In this paper, a new kind of 2-DOF parallel manipulator actuated horizontally by two parallel linear actuators is investigated. Firstly, the four inverse solutions of this manipulator are derived and analyzed; Secondly, the closed form inverse dynamic model is presented using the Lagrange approach based on the generalized system coordinates. An explicit formula of the equivalent moment of inertia, driving forces and consumed energy of the mechanism are investigated; Finally, the changes of equivalent moment of inertia, actuator force and energy consumption of the mechanism in different operating mode are analyzed through the dynamic numerical simulation. The results show that, for a given motion, the configuration and the operating modes have a significant influence on the equivalent moment of inertia and actuator force. The analysis provides necessary information for dynamic performance analysis and control of this parallel manipulator.

Abstract: This paper addresses geometry design and operating mode optimum design of a new kind of 2-DOF parallel manipulator actuated horizontally by linear actuators. The forward and inverse kinematics of this manipulator are derived. The four groups of inverse solution correspond to four different operating modes which cannot transit to each other smoothly. The workspace and the singularity trajectory of each mode are discussed. Based on the desired workspace, the geometry of the mechanism is determined. The operating mode of the mechanism is optimized according to distributing of all global and local performance indices on the workspace. The results are very useful for the design and application of the new manipulator with multiple forward and inverse solutions.