Papers by Keyword: Kinematical Analysis

Abstract: The purpose of this paper is not to elaborate the bionic pattern of walking robot, but to elaborate our own simple idea of a 4 degree of freedom (DOF) walking robot with the ability to walk on flat surfaces, rotate and climbing upstairs, which is composed of vertical moved legs with a rotary foot and a controlled mass for stabilizing. In this paper, based on the former idea, a prototype model of a 3-DOF walking robot is presented for walking only on flat surfaces. This walking robot is actuated by servo motors. The paper covers the kinematics, centre of gravity analysis, description of the robot and its control system made using Pololu controller. Experiments confirmed the feasibility of the proposed design.

Abstract: The purpose of this paper is to elaborate not on the bionic pattern of walking robot. Our own simple idea of 4 degree of freedom (DOF) walking robot with the ability to walk on flat surfaces, rotate and climbing upstairs was made using vertical moved legs with rotary foot and additional controlled mass. In this paper, based on former idea, prototype model for only flat surface walking task 3 DOF were presented. Parts of the robot are moving thanks to servo motors. The paper contains kinematics and centre of gravity analysis, presentation of robot and its control system made using Pololu controller. Conducted experiments confirmed presented idea.

Abstract: Vibration-assisted turning combines conventional turning with high-frequency, small-amplitude tool vibration to improve the machining quality of intractable materials like titanium and nickel alloys used in aerospace applications. Elliptical vibration-assisted turning is a kind of two-dimension vibration-assisted turning. The tool tip is driven in an elliptical locus. This paper illustrates a miniature cutting tool designed for elliptical vibration-assisted turning and proposes a set of general formulas by kinematical analysis. These formulas show the effects of different vibration parameters on the final elliptical locus, and these effects are verified using MATLAB at the end of this paper.

Abstract: This paper presents an invertebrate leg-like mechanism, which is biologically inspired from invertebrate creatures such as crabs and insects. For the purpose that the leg mechanism could imitate the behavior of the invertebrate animal on rough terrain, it should have the same degree of freedom as the crabs or insects have. The novel leg mechanism consists of 3 joints which linkage has 5 degrees of freedom (DOFS), and mainly depends on a coxa joint driven by a parallel mechanism for the biomimetic motions. The parallel mechanism with 3 DOF is well designed and implemented with the excellent kinematical performances as invertebrate creatures. The mathematical model of the leg mechanism and the kinematical analysis are described, and static force performance characteristics are also discussed. The kinematical performances of the leg mechanism are analyzed by the numerical simulation conducted in biomimetic robots application. The simulation results show the performance of the proposed leg-like mechanism and verify that the leg can be used in the biomimetic robot which could exactly imitate limb motions.

Abstract: Positioning problem is considered for the 3^rd class lever linkage with dwell of the output link according to the given cyclogram and slider guide position. Using parametric synthesis and selected parameters of the 3^rd class mechanism the kinematical analysis is carried out. The calculated parameters of velocity and acceleration provide quality of motion within limitations. This gives opportunity to use the mechanism in automatic machines.

Abstract: To assist stroke patients with rehabilitation training, an upper limb rehabilitation robot with an exoskeleton structure and three degrees of freedom (DOF) was developed in this paper. Under the guidance of the theory of rehabilitation medicine, the mechanical design of the robot was completed. Then, the kinematics equations were established by means of homogeneous transformation, including the forward kinematics and the inverse kinematics. The kinematical analysis was carried out and the algebraic solution of inverse kinematics was derived, which provided a theoretical basis for realizing the intelligent control. To validate the performance, the kinematical simulation was conducted, and the simulation results showed that the design of the exoskeleton robot was feasible.

Abstract: Electrochemical micro-machining (EMM) appears to be very promising as a future micro-machining technique, since in many areas of applications, it offers many advantages, which include excellent machining precision and control, high machining rate, perfect surface quality and a wide range of materials that can be machined, regardless of their strength and toughness. In the paper, a new style EMM equipment for micro-holes is presented. Double vertical column style structure is chosen as the main mechanical structure of the equipment, which has the advantage of excellent structure rigidity, compact framework dimension as well as good maneuverability and maintainability. In order to verify the reliability of this EMM equipment, some measurement works including static measurements, assembling interferences checking and kinematics simulation have been done. Furthermore, the low-speed kinematics characteristics of the developed EMM equipment are concentrated. The kinematics simulation results indicate that the developed EMM equipment can satisfy the requirements for low-speed motion and anti-interference characteristics of EMM process.

Abstract: A 5-axis parallel-serial machine tool is proposed, which consists of a 3-DOF parallel mechanism and a 2-DOF serial mechanism, and the kinematics analysis is discussed in detail based on the vector method. The size of the velocity transformation matrix is decreased. The problem of parameter coupling is resolved by adopting identity matrix and four-element vector. The relationship between the velocity and acceleration of the movable platform and the input parameters of the parallel mechanism is established. These algorithms are verified correct through ADAMS (Automatic Dynamic Analysis of Mechanical System) and can be referenced by kinematics analysis, dynamics analysis of parallel or parallel-serial machine tools, which have coupling kinematics parameters.

Abstract: The two novel 1-translation and 2-rotation parallel mechanisms are 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 pros and cons are addressed by comparing with the two parallel mechanisms, and the optimal one of the two mechanisms is produced.The work of the paper provided a solid foundation for mechanical structural design and real-time controlling of the novel parallel mechanism.

Abstract: A novel robot, derived from a planar parallel mechanism, is presented. With two sliders driving on the same side of parallel guide rails, this simple but practical mechanism is capable of realizing a large workspace. The direct and inverse kinematical solutions are given. The simulation demonstrates that all kinds of straight lines and circles can be realized by the end actuator of the robot; the corresponding motion disciplines and characteristics driven by the two sliders are analyzed; the results are verified on the prototype. By allowing the end actuator to move in Z-direction or to rotate around A or B-axis, three-, four-, five-axis manipulator would be composed and surface welding and space cutting would be realized. This paper lays the foundation for the real-time control and industrial application of this novel robot.