Applied Mechanics and Materials Vol. 620

Abstract: In order to study the dynamic performance with respect to a drum type washing machine, a detailed three dimensional dynamic model considering six degrees of freedom is established in the commercial software Adams. The characteristics of model are in good consistency with the simulation results on the movement of measure point in the x-z plane and eigen modes of the rigid body system. An automatic counterbalancing model of balls with different torsion damping coefficient is designed for vibration reduction. The parameters affecting the vibration are investigated by the approach of design of experiments which can reduce design cycle significantly. Its optimization results show a good performance compared to a washing machine model without balance balls attached.

Abstract: For the fracture failure phenomena occurred in random vibration experiment of the isolation clamp cylinder on the aerospace vehicles, the NX NASTRAN was used to make the finite element modeling for the overall structure of cylinder and analyze the random vibration response. The simulation results show that the maximum RMS stress of the clamp was 96 MPa at the test load conditions. The position of the maximum RMS stress is consistent with the one where fracture happens during vibration test. According to finite element analysis results, the original structure has been modified. The maximum RMS stress of modified structure is only 21.8 MPa.

Abstract: A cross-coupled proportional-integral-derivative neural network (PIDNN) control is proposed in this study for the synchronous control of a dual linear motors servo system which is installed in a gantry position stage. First, the dynamics of the field-oriented control PMLSM servo drive with a lumped uncertainty, which contains parameter variations, external disturbance and friction force, is introduced. Then, to achieve accurate trajectory tracking performance with robustness, an intelligent control approach using PIDNN is proposed for the field-oriented control PMLSM servo drive system. In the proposed approach, the on-line learning algorithms of the PIDNN are derived using back-propagation (BP) method to guarantee the convergence of the network. Finally, some experimental results are illustrated to depict the validity of the proposed control approach.

Abstract: In order to study the elastic motion stability of flexible manipulator arm , to compute the maximum dynamic allowable payload , the partial differential equation of elastic motion of the flexible manipulator arm is solved using the method of Laplace transformation , the dynamic model of flexible manipulator arm carried addition mass on its end position is established ,simplified and truncated using Lagrange equation . the state space expression is established with the state variable and control input and output variable designated , the elastic motion stability rule is built upon and simplified using Lyapunov stability theory . The influence of the end position addition mass and articulation rotational inertia of flexible manipulator arm on its elastic motion stability is analyzed using the stability rule , and the dynamic maximum allowable payload of flexible manipulator arm on its end position is computed in order to guarantee its elastic motion stability . this study is important to the design of robot mechanical manipulator and corresponding drive control system .

Abstract: In order to study the elastic motion stability of flexible manipulator arm , to analyze the effect of the end position addition mass and rotary inertia on the elastic motion stability ,and to compute the maximum dynamic allowable payload , the physics model of a flexible manipulator arm is established , the differential equation of elastic motion of the flexible manipulator arm is solved using the method of the separation of time and space and the method of Laplace transformation , the dynamic model of flexible manipulator arm carried addition mass on its end position is established ,simplified and truncated using Lagrange equation . the state space expression and transfer function are established with the state variable and control input and output variable designated , the elastic motion stability rule is built upon and simplified using Roth criterion . The influence of the end position addition mass and articulation rotational inertia of flexible manipulator arm on its elastic motion stability is analyzed using the stability rule and the dynamic maximum allowable payload of flexible manipulator arm on its end position is computed in order to guarantee its elastic motion stability .

Abstract: This paper discusses some specific problems in the process of palletizing firebrick by industrial robot, and then discusses the optimization of the palletizing method by proposing two optimization goals. First, a mathematical model containing two objectives for the optimization is constructed according to the palletizing problem. Then, in order to solve this optimization model, this paper uses the Pareto genetic algorithm, and states the procedure of this method in detail. Finally, an example is taken to prove the effect of the optimization model by using MATLAB.

Abstract: The paper introduces kinematics analysis for a kind of 6 degrees of freedom underwater manipulator. Firstly, kinematics model was established based on D-H principle; The solving process of kinematics direct solution and inverse solution of manipulator was presented. Secondly, Numerical simulation is performed based on ADAMS software, every joint speed and acceleration curve is obtained. The working principals and control requirement of underwater manipulator are illustrated; Based on kinematics modeling, the control system of manipulator was designed based on PLC and carried out the control the function of the manipulator.

Abstract: Hardware-in-the-loop simulation is widely used for component and controller testing, for which purpose a transfer system typically comprising sensors and mechanical actuators is used to link the software and hardware subsystems. The effect of coupling the transfer system to the test system can be ignored for a steady or slowly changing process, but not for a highly dynamic process. In this paper, we propose a feedforward methodology for compensating for the coupling effect without increasing the noise bandwidth designed for a steady or slowly changing process when simulating a dynamic process. We also present an analysis of the results of the experiments in automotive engineering used to verify the proposed methodology.

Abstract: An embebbed system based on S3C6410 controller and Linux operating system is established to overcome the deficiencies of the traditional control system for high accuracy processing of grinding diesel injector nozzle because of its high speed and real-time performance. In this paper,the general structure of the system is designed firstly. Secondly, the detailed hardware platform is constructed and its peripheral equipment is selected. In addition,the software structure is presented. Finally, the main application program,including of processing control program and algorithm of the flow signal processing which is the key factor for high accuracy maching, is studied. The actual processing data shows that this system has good real-time performance, high processing accuracy and stablity.

Abstract: Through taking the appearance design of Guiding Robot Xiaomai which is used for the 60th anniversary of HUST as example and summarizing the result and experience in course teaching, this article mainly discusses the importance of project teaching in the teaching link of Product Design. The result shows Project teaching is a way of student-centered learning with multi-disciplines, collaborative learning, self-exploration and living practice [1]. It enables students to learn knowledge more targeted and systematically. And it greatly improves students’ ability of overall planning, hand-making, communication and teamwork spirit, which produces teaching effect that is far superior to the traditional teaching.