Kinematic Analysis Of Planar Mechanisms Research Articles

The Manufacture of Curved Crease Surfaces Starting from Kinematic Analysis of Planar Mechanisms

Achieving curved crease surfaces is a current challenge for designers, the field still underexplored. The curve on which the bending is performed can present extremely complicated shapes that must be accurately generated through various technological processes. For this aim, a planar mechanism consisting of an ellipsograph, a conchoidograph and an RRR dyad—whose inner joint generates the targeted connecting rod curve—was proposed in this paper. Parametrizing the lengths of the elements of the RRR dyad, the correlation coefficient of the rotations of the leading elements and the directions of these movements result in different connecting rod curves, which can be used to obtain the folded surfaces; the optimization, according to various criteria, will be explored for the automatic generation of some design solutions. With the help of the Altair program, for some given geometrical data of the mechanism, both the drawing of the curve on plates of different initial shapes and the simulation of their folding by applying compression forces on the bounding surfaces were carried out. By cutting the deformed shape, folded surface units used in tessellations are obtained.

Kinematic and dynamic analysis and distribution of stress for seven-item mechanism by means of the SolidWorks program

This paper presents a kinematic and dynamic analysis and distribution of the stress for seven-item planar mechanism by means of the SolidWorks software. The authors of the introduced paper deal with the kinematic analysis of planar mechanisms as well as with the implementation of the vector method into the SolidWorks software program in order to determine the kinematic variables (quantities) of the individual bodies in the whole complex system. The dynamic analysis is performed on the basis of the kinematic analysis. Dynamic analysis allows us to design a system of bodies correctly and it is with the respect to the dynamic loading. For the interpretation of the introduced analysis, the seven-item planar mechanism was selected. Graphic dependence of kinematic and dynamic magnitudes of some points is given in dependence on the angle of rotation of the driving item and in dependence on time. In relation to the kinematic and dynamic analysis and subsequent simulation of the planar as well as spatial mechanisms, it is perfect solution to use SolidWorks software program. The considerable advantage of this mentioned program is based on its simplicity from the aspect of modeling and moreover, it is important to point out that utilisation of the mentioned program leads to results which are precise and accurate in the case of the numerical solution of the equations in the whole magnitude referring to motion of mechanism while the given results are obtained in the graphic form.

Kinematic and dynamic analysis and distribution of stress for six-item mechanism by means of the SolidWorks program

This paper presents a kinematic and dynamic analysis and distribution of the stress for six-item planar mechanism by means of the SolidWorks software. The main purpose of the investigation is connected with the kinematic analysis of planar mechanisms as well as with the implementation of the vector method into the SolidWorks software program in order to determine the kinematic variables of the individual bodies in the whole investigated system. The process of the dynamic analysis is based on the kinematic analysis. The dynamic analysis makes possible to design a system of bodies correctly and it is with the respect to the dynamic loading. For the interpretation of the introduced analysis, the six-item planar mechanism was used as example (representative). Graphic dependence of kinematic and dynamic magnitudes of some points is given in dependence on the angle of rotation of the driving item and in dependence on time. In relation to the kinematic and dynamic analysis and subsequent simulation of the planar as well as spatial mechanisms, it is great solution to use SolidWorks software program. The considerable advantage of this mentioned program is based on its simplicity from the aspect of modeling and moreover, it is important to point out that utilisation of the mentioned program leads to results which are precise and accurate in the case of the numerical solution of the equations in the whole magnitude referring to motion of mechanism while the given results are obtained in the graphic form.

Corrigendum to “A unified analytical parametric method for kinematic analysis of planar mechanisms”

Corrigendum to “A unified analytical parametric method for kinematic analysis of planar mechanisms”

A unified analytical parametric method for kinematic analysis of planar mechanisms

This paper describes a method for unified parametric kinematic analysis of those planar mechanisms whose geometry can be defined with a set of independent vectorial loops, i.e. solvable independently; this covers a wide range of planar mechanisms. The method is developed by employing the well-known vectorial illustration, and vectorial-loop equations solved with the aid of complex polar algebra leading to a total of only nine unified/generic one-unknown parametric equations consisting of five equations for position analysis and two equations for velocity and acceleration analysis each. Then, the kinematics of joints and mass centers are manifested as resultants of a few known vectors. This method is needless of relative-velocities, relative-accelerations, instantaneous centers of rotation and Kennedy’s Theorem dominantly used in the literature, especially textbooks. The efficiency of the method is demonstrated by its application to a complex mechanism through only eight unified equations, and simultaneously compared to the solution using the textbook common (Raven’s) method which required the derivation of 67 extra equations to get the same results. This reveals the fact that the method is not only a powerful tool for mechanical designers but a most powerful and efficient method for teaching and learning the kinematics of planar mechanisms.

A method of optimization of solving a kinematic problem with the use of structural analysis algorithm (SAM)

The heart of the work is a method of structural analysis of planar mechanisms (SAM) allowing for separation of Assur groups, being the smallest kinematically well determined kinematic chains. The algorithm is aimed at minimizing the numerical expense of determining the kinematic parameters (i.e. velocities and accelerations) of the mechanisms. In order to present operation of the SAM algorithm an algorithm designed for kinematic analysis of planar mechanisms with revolute and prismatic joints has been proposed. The ways of defining the input parameters and Jacobian generation have been discussed. It was checked whether the proposed way ensures correct formulating of the kinematic problem. The Jacobian achieved this way is ordered with the help of the SAM to the form converting the global kinematic problem into the solutions in particular groups. The algorithms presented here are designed and proposed in the forms enabling their numerical implementation. Theoretical consideration was supported with a numerical example.

A Generalized Approach for the Kinematic Analysis of Planar Mechanisms

This paper describes a new approach to the kinematic analysis of planar mechanisms. The basis of the analytical method is a generic four-bar sub-mechanism which is used as the single building block from which other composite mechanisms may be created. A computer program has been written embodying this method and has been demonstrated to operate successfully providing animated displays of displacement, velocity and acceleration diagrams for a wide range of complex mechanisms.

Kinematic simulations of planar mechanisms

Kinematic analysis and simulation of mechanisms are basic tasks in machine design and can be easily automated using microcomputers. Such programs can free a user of tedious calculations and be instructive in the kinematics of linkages; however, the quality of user interface in such programs can prove discouraging to their general use. A well-designed program should have minimum-keystroke, self-guiding data input, useful and concise output, and descriptive error-trapping. KPLAn (Kinematic Planar Linkage Analysis) is a state-of-the-art program, developed for the kinematic analysis of planar mechanisms using the vector loop-closure method. Interactive pop-up windows, cursor-selectable menus are used to create an eye-pleasing, uncomplicated format and graphical displays are emphasized for immediate visual impact. The result is a program that is very user-friendly and yet sufficiently sophisticated to guide a user informatively. KPLAn produces output in three formats: animated motion simulation; graphed curves of displacements, velocities and accelerations; and numerical tabulation of these quantities. To demonstrate and assess the utility of KPLAn, two examples are presented.

Computer-Aided Kinematic Analysis of Planar Mechanisms Based on Symbolic Pattern Matching of Independent Kinematic Loops

Based on a problem decomposition strategy and a symbolic kinematic loop pattern matching technique, a new method for planar mechanism kinematic analysis has been uncovered. Since this approach directly applies an analytical, closed form solution methodology to the planar mechanism kinematics problem, a number of significant advantages over other solution methods have been observed. Firstly, when applicable, this new approach requires significantly less cpu time as compared with traditional numerical methods, making timely mechanism animation feasible. Secondly, the new approach eliminates the effect of computer truncation error, thereby eliminating numerical approximation errors. Finally, it can be used to search for initial positions of planar mechanism with specified dimensions, thereby enabling automatic mechanism sketching.

A study on completely computer-assisted kinematic analysis of planar link mechanisms

For the purpose of complete computerization of the kinematic analysis of planar mechanisms, an iterative process of analysis has been determined by means of incidence matrices of prime structures. The prime structures have been defined as the structures composed of pin-jointed links that cannot be derived from other structures, and some of them have been introduced together with positional relations of their joints. Moreover, it is shown that kinematic analyses can also be carried out by means of the prime structures.