Papers by Keyword: Kinematics

Abstract: Aiming to the layout structure design and performance prediction for globoidal cam machine, a dynamic performance prediction method for machine layout structure is proposed in this paper. With the method, the motion transmission and layout structure are determined based on the mapping rules between function and structure. The prediction model for dynamic performance is established based on BP neural network, which is used to optimize the dynamic performance of layout structure for globoibal cam machine.

Abstract: Using mechanism design and dynamic analysis software, the simulation is conducted about grasping operation and moving objects for multi redundant manipulator on the basis of mechanism design and theoretical research, as well as the snake crawling motion simulation. The simulation results validate the correctness of theory analysis. The each joint driving torque data and curve provided the effective data basis for the design and development of a prototype.

Abstract: This paper describes a new genre of Toroidal-CVT system, called the Sphere-Toroidal Continuously Variable Transmission (STCVT), which is derived from the half-toroidal traction drive (TCVT) and introduces its structure and working principle. The torque transfers from the input shaft to the cross-axle universal shaft coupling connected with the driven shaft. By discussing the difference between the torque-transfer, the paper will show the possibility of the application in the vehicle. To conclude, the system has the potential to implement infinite extension for the CVT theoretically.

Abstract: Designing a humanoid robot is a complex issue and the exact resemblance of human arm movements has not been achieved in many of the previously developed robots. This paper is going to be much focused on the design of a humanoid robot arm which has a unique approach which has never been developed earlier. Even though all the robots that have been developed using 6-Degrees of Freedom (DOF) and 7-DOF can reach any point in the space, some of the orientation cannot be reached by the end effector plane effectively. So an 8-DOF freedom based robotic arm has been specially designed and developed to resemble the exact movements of the human being. This robot has 3-DOF for shoulder joint, 2-DOF for the elbow joint, and 3-DOF for the wrist with fingers as the end effector. Almost all the robots have only 1-DOF to the elbow joint but here 2-DOF has been proposed to resemble the exact movements of the human being (2-DOF at elbow) to solve the above mentioned problem. Literature reviews and design model are discussed in detail to support the proposal that has been made. Forward and inverse Kinematic relationships are also obtained for the joint link parameter. This humanoid robot arm which has been designed and developed is one of the modules of a human size humanoid robot RALA (Robot based on Autonomous Learning Algorithm).

Abstract: The objective of this paper is to study performance of triangular elbow transmission mechanism for servo press. Then kinematics models are deduced and given. Kinematics curves along slider motion direction are drawn. Moreover, under the same driving condition, the effects of different link ratios on slider output motion are examined and compared with common six bar transmission mechanism in the article. Through motion curves comparison, it can be seen that this triangular elbow mechanism has significant force increasing effect and good quick-return characteristics. In addition, we carried on triangular elbow servo press virtual design and simulation. The case study provides more visual and reliable decision basis for designer. The results would be useful reference for optimization design of transmission mechanism.

Abstract: Using biomechanical test system to reveal the kinematics parameters of instep shot in different heights in soccer players. Twelve healthy male college students voluntarily participated in this study. After digitizing the recording collected by camera, this study reached the following conclusion that (1) In instep front shot the lower the contact height with ball during kicking, the faster the ball velocity. Therefore, the author put forward a proposal that in order to obtain the faster ball velocity, the kicking ball point should be lower, and (2) the player can control the ball velocity, ball trajectory, and the time of technique by controlling the vertical distance between support leg and ball.

Abstract: The paper aims at the questions of electromotor selection and mechanism design, which is effectively solved by the virtual prototype technology. Firstly, the three-dimensional model of hybrid machine tool is built by using SolidWorks software. Secondly, the assembled model is channeled into ADAMS/View, and then formed the virtual prototype simulation model with mute-body dynamics. Velocity and driving force curve of each driving shaft is got by analyzing the kinematics and dynamics of the hybrid machine tool. Maximum velocity and maximum driving force each driving shaft can find out by the method of space search. Therefore, the kinematics and dynamics properties of 3-TPS hybrid machine tool is obtained, which provide proof for machine electromotor selection, framework design and control system design. Key words: Hybrid robot; Kinematics; Dynamics; ADAMS; Simulation

Abstract: By combining the industrial design software UG and finite element dynamic analysis software ANSYS/LS-DYNA, the paper respectively designs the non-linear knitting cams with polynomial curves, and simulates the loop-forming process in the interaction between the cams and needles. Based on comparative analyses, it’s thereby concluded that the polynomial curve has the best performance and is significantly superior to the cam curve composed of straight-lines and circular-arcs; the elements with higher stresses are located above the butt of needle jack and the joint of the jack and latch needle; and the polynomial curve is effective in lowering the maximum stress of the needle.

Abstract: The semi-automatic feeding mechanism of vegetable transplanter was nacelle basket type which is available with manual feeding for transplanting vegetable potted seedlings. However, the efficiency is lower to meet the needs. To improve it, a new design of the potted seedling pick-up mechanism with double crank geared five-bar linkages model was expounded for automatic seedling picking. The kinematics model of the pick-up mechanism was established by mathematical analysis method. The influence of the structural parameters on the motion trajectory and relative velocity of the seedling pick-up arm cusp was investigated. The design of optimization objective for picking vegetable potted seedling was proposed. Meanwhile, the optimal parameter combination of the pick-up mechanism was obtained by using MATLAB based on the objective. With it, when the seedlings pot were being pulled out, the path of the seedling pick-up arm inserting was straightly and more perpendicular to potted seedling. Furthermore, the velocity of seedling taking and dropping cusps were relatively lower in order to meet the speeds demand of seedling picking up with seedling feeding in automatic way.

Abstract: This paper is the discussion and analysis of first serve for the ATP champions tour Chengdu open contestant called Carlos Moya who was the grand slam champion of French open and Thomas Enqvist who was the champion of ATP World Tour Masters 1000,and to find out some regular patterns and features,to demonstrate the principle of kinematics of tennis, aimed at providing some methods for tennis athletes’ training and competition in the future,as well as make some statistics for the coaches to guide the tennis players in the serve tactics. In today's era of tennis serve for high speed development, the elite tennis players are more than 193 km per hour, and a top speed of 251 km of ACES to show us the charm of the tennis serve.Serve is the main means of scoring to win the match, especially the first serve,is offensive weapons,the quality of first serve directly influences of the set of serve for player,high quality of first serve make difficult for opponent from the start,at the same time,they can score initiative by first service,and is a prerequisite to win the set of serve.Therefore,it is the start of the game and the start of attack.The quality of first serve is the key factor of the game.