Papers by Author: Hong Yi Liu

Abstract: To solve the inverse kinematics problem of a robot manipulator without closed form solutions, one-dimensional iterative method is very useful. However, for a 5-DOF robot manipulator, because of the uncontrolable and uncertain orientation vectors, it's difficult to analytically express all joint variables by one of them, therefore one-dimensional iterative method can not be directedly used. By adding an appropriate virtual joint to it, a 5-DOF manipulator can be changed into a 6-DOF one so that the uncertain orientation vectors can be pre-given, and the difficulty is solved. To illustrate this virtual joint method a 5-DOF serial robot manipulator with prismatic arm joint and offset wrist is discussed in this paper as an example.

Abstract: The efficiency of continuously variable transmission for vehicle is an important factor impacting on its performance, many kinds of power loss in process of shifting down and up are analyzed by means of theoretical and experimental ways, it can be seen that the power loss between metal-belt and pulley, which includes three items of loss: the entering and out of pulley; the slip between elements and surface of pulley; the slip of between steel bands and elements, is a major one. The calculating formulas are founded. The comparison of calculating results with experimental results under the different ratio, it is good coherence between them which has a guiding function for the design of TCU.

Abstract: A design method is presented for a polishing robot in unstructured working environment. Setting up a structure model of the polishing system, and the operation principle and control method are described. The human-simulated intelligent control method is applied to the control of contact force in unstructured environment, because of the uncertainty, variability and unstructured of the environment. The basic idea of the intelligent control method is based on the size of error and change direction of control variables. The conditions of the control rules and control decision are inferred by forward reasoning. The HSIC controlling function is achieved, which can strengthen people energy to revise and control the interaction force and position of the end-effector.

Abstract: Based on development project of electro-mechanical control type continuously variable transmission, this paper has done the following works: First of all, the structure and working principle of EM-CVT is studied; then, mathematical model was established; finally, via numerical simulation, Performance Parameters of transmission system, such as mechanical characteristics, dynamic performance of execution system are mastered in the transmission process of EM-CVT. Analysis of the study will contribute to the development of high-quality and highly efficient controller for EM-CVT.

Abstract: The performance of solenoid valve is directly related to the security and reliability of industrial system. This paper presents the design of the automatic test platform for solenoid valve. The architecture of the hydraulic subsystem and the control model of providing precise pressure for testing solenoid valve were built up. A self-adaptive fuzzy PID controller, which can dynamically modify the controller’s parameters by using fuzzy rules presented in this paper, was designed with considering the dynamic characteristics of hydraulic system. Simulation results show that the self-adaptive fuzzy PID controller, which compared with conventional PID controller, can obtain better dynamic performance and fast response.

Abstract: The stress field simulation is carried on to the solenoid valve product during the impulsive load using the ANSYS software in this article, and the stress calculation and fatigue strength assessment to the key dangerous section of valve are done. The result indicates that the dangerous section is proved to satisfy the strength requirement during the impulsive load, and the theory basis has been provided for the further structure optimization design and the performance improvement of solenoid valve.

Abstract: The laying pipe manipulator is used to lay concrete pipe, and it solves the question of safety, quality, and efficiency in the pipe laying construction site, and the critical question of locating system is studied. The work principle and mathematical model of locating system were established, and the experiment of locating system was done. According to the test result, the work principle and mathematical model of locating system had turned out to be well adapted for requirement. The locating system of laying pipe manipulator can be applied to product development. The mathematical model of locating system supplies the basic control theory for the manipulator to lay and joint concrete pipe automatically.