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

1990 ◽  
Vol 112 (3) ◽  
pp. 337-346 ◽  
Author(s):  
Wei-Hua Chieng ◽  
D. A. Hoeltzel

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.

Author(s):  
Ye-Hwa Chen

A new approach to the control design for fuzzy dynamical systems is proposed. For a fuzzy dynamical system, the uncertainty lies within a fuzzy set. The desirable system performance is twofold: one deterministic and one fuzzy. While the deterministic performance assures the bottom line, the fuzzy performance enhances the cost consideration. Under this setting, a class of robust controls is proposed. The control is deterministic and is not if-then rules-based. An optimal design problem associated with the control is then formulated as a constrained optimization problem. We show that the problem can be solved and the solution exists and is unique. The closed-form solution and cost are explicitly shown. The resulting control is able to guarantee the prescribed deterministic performance and minimize the average fuzzy performance.


1992 ◽  
Vol 114 (3) ◽  
pp. 438-443 ◽  
Author(s):  
B. Padmanabhan ◽  
V. Arun ◽  
C. F. Reinholtz

A variety of applications for variable-geometry truss manipulators (VGTMs) have been demonstrated or proposed in the literature. Most of these applications require solution to the inverse kinematic problem, yet only a few isolated examples of closed-form solution methods have been presented to date. This paper provides an overview to the general problem of inverse kinematic analysis of variable-geometry truss manipulators and presents new closed-form solution techniques for problems of practical importance.


1960 ◽  
Vol 27 (3) ◽  
pp. 501-504
Author(s):  
S. F. Borg

A fundamentally new approach to the rupture-fracture problem is presented. Because of the particular type of dynamic phenomena being investigated, the formulation is given in terms of the conservation equations of continuum mechanics instead of in the usual elasticity-plasticity relations. The introduction of a similarity co-ordinate permits a complete closed-form solution to a particular problem of practical interest subject to certain compatibility conditions which depend upon the specific properties of the material under consideration.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Jaime Gallardo-Alvarado ◽  
Jesus H. Tinajero-Campos

This work reports on the kinematic analysis of a planar parallel manipulator endowed with a configurable platform assembled with six terminal links serially connected by means of revolute joints. This topology allows the robot manipulator to dispose of three relative degrees of freedom owing to the mobility of an internal closed-loop chain. Therefore, the proposed robot manipulator can admit three end-effectors. The forward displacement analysis of the configurable planar parallel manipulator is easily achieved based on unknown coordinates denoting the pose of each terminal link. Thereafter, the analysis leads to twelve quadratic equations which are numerically solved by means of the Newton homotopy method. Furthermore, a closed-form solution is available for the inverse position analysis. On the contrary, the instantaneous kinematics of the robot manipulator is investigated by means of the theory of screws. Numerical examples are included with the purpose to illustrate the method of kinematic analysis.


Author(s):  
A K Khare ◽  
A C Rao

Structural error synthesis of mechanisms is usually carried out either by the precision point approach or by using optimization techniques. A new approach for such problems using the reliability concept is presented in this paper. Besides being simple, this approach leads to a closed form solution and the mechanism can be designed to perform with any desired reliability. Its application is illustrated by means of a numerical example and the results are compared with those available.


2011 ◽  
Vol 3 (3) ◽  
Author(s):  
Nicolás Rojas ◽  
Federico Thomas

The exact position analysis of a planar mechanism reduces to compute the roots of its characteristic polynomial. Obtaining this polynomial almost invariably involves, as a first step, obtaining a system of equations derived from the independent kinematic loops of the mechanism. The use of kinematic loops to this end has seldom been questioned despite deriving the characteristic polynomial from them requires complex variable eliminations and, in most cases, trigonometric substitutions. As an alternative, the bilateration method has recently been used to obtain the characteristic polynomials of the three-loop Baranov trusses without relying on variable eliminations nor trigonometric substitutions and using no other tools than elementary algebra. This paper shows how this technique can be applied to members of a family of Baranov trusses resulting from the circular concatenation of the Watt mechanism irrespective of the resulting number of kinematic loops. To our knowledge, this is the first time that the characteristic polynomial of a Baranov truss with more that five loops has been obtained, and hence, its position analysis solved in closed form.


Author(s):  
Sh Hosseini-Hashemi ◽  
S R Atashipour ◽  
M Fadaee

Based on Reddy's third-order shear deformation theory, an exact closed-form solution is proposed to describe linear buckling of transversely isotropic laminated rectangular plates under either mono- or bi-axial compressive in-plane loads. To this end, the coupled governing equations are exactly converted to two sets of uncoupled equations for in-plane and transverse deformations of symmetric laminated plates. The new uncoupled equations are analytically solved by applying both Navier and Lévy-type solution methods. The validity and high accuracy of the current exact solution are evaluated by comparing the present results with their counterparts reported in literature.


Author(s):  
Carlos G. Manríquez-Padilla ◽  
Karla A. Camarillo-Gómez ◽  
Gerardo I. Pérez-Soto ◽  
Juvenal Rodríguez-Reséndiz ◽  
Carl D. Crane

This paper presents a novel class 2 tensegrity robot which has contact between its rigid elements with a universal joint. Also, an strategy to obtain the forward and inverse position kinematic analysis using the parameters Denavit–Hartenberg in the distal convention is presented, obtaining the closed–form solution for the inverse position analysis and it was validated through simulation where a point of the robot followed the desired trajectory. Finally, the results were implemented in the experimental prototype of the novel class 2 tensegrity robot.


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