Order Rectification for Complex Number Based Burmester Curves

1991 ◽  
Vol 113 (3) ◽  
pp. 239-247 ◽  
Author(s):  
T. R. Chase ◽  
W. E. Fang

A new solution to the order rectification problem for a driving dyad of planar mechanisms is presented. The method identifies sections of both Burmester curves where the driving link rotates in a single direction when passing through four precision positions in sequence. The new solution describes desirable regions of the curves in terms of the complex number parameters used to generate the curves, providing a complex number equivalent to available pole based order rectification procedures. The new solution is stated in a summary form that is readily codifiable. An example is presented. The theory underlying the new solution is then developed in detail.

1973 ◽  
Vol 95 (2) ◽  
pp. 572-576 ◽  
Author(s):  
R. E. Kaufman

A unified complex number development of four position planar finite position theory is presented. This formulation shows that Burmester circlepoint-centerpoint theory specializes to include slider points, concurrency points, poles, and point position reduction by proper interpretation of the trivial roots of the general synthesis equations. Thus a single design technique can be used for the multiposition synthesis of most pin or slider-jointed planar mechanisms. Four position function, path, or motion generating linkages can all be designed in this manner.


1982 ◽  
Vol 17 (6) ◽  
pp. 405-414 ◽  
Author(s):  
George N Sandor ◽  
E Raghavacharyulu ◽  
Arthur G Erdman

1982 ◽  
Vol 104 (1) ◽  
pp. 233-238 ◽  
Author(s):  
G. N. Sandor ◽  
A. G. Erdman ◽  
L. Hunt ◽  
E. Raghavacharyulu

New complex number forms of the Euler-Savary Equation (ESE) for higher-pair rolling contact planar mechanisms were derived in a former paper by the authors. The present work, based on the former, deals with the derivation of the cubic of stationary curvature (CSC) in complex-vector form, suitable for digital computation. The CSC or Burmester’s circlepoint curve and its conjugate, the centerpoint curve for four infinitesimally close positions of the moving plane requires taking into account not only the curvature but also the rate of change of curvature of the rolling centrodes in the immediate vicinity of the position considered. The analytical procedure based on the theory developed in the present paper, when programmed for digital computation using complex arithmetic, takes care of the algebraic signs automatically, without the need for observing traditional sign conventions. The analysis is applicable to both higher-pair and lower-pair planar mechanisms. An example using the complex-number approach illustrates this.


1982 ◽  
Vol 104 (1) ◽  
pp. 227-232 ◽  
Author(s):  
G. N. Sandor ◽  
A. G. Erdman ◽  
L. Hunt ◽  
E. Raghavacharyulu

It is well known from the theory of Kinematic Synthesis of planar mechanisms that the Euler-Savary Equation (ESE) gives the radius of curvature and the center of curvature of the path traced by a point in a planar rolling-contact mechanism. It can also be applied in planar linkages for which equivalent roll-curve mechanisms can be found. Typical example: the curvature of the coupler curve of a four-bar mechanism. Early works in the synthesis of mechanisms concerned themselves with deriving the ESE by means of combined graphical and algebraic techniques, using certain sign conventions. These sign conventions often become sources of error. In this paper new complex-number forms of the Euler-Savary Equation are derived and are presented in a computer-oriented format. The results are useful in the application of path-curvature theory to higher-pair rolling contact mechanisms, such as cams, gears, etc., as well as linkages, once the key parameters of an equivalent rolling-contact mechanism are known. The complex-number technique has the advantage of eliminating the need for the traditional sign conventions and is suitable for digital computation. An example is presented to illustrate this.


1987 ◽  
Vol 109 (4) ◽  
pp. 426-434 ◽  
Author(s):  
T. R. Chase ◽  
A. G. Erdman ◽  
D. R. Riley

A new synthesis tool, the triad, is introduced to enable simplified synthesis of very complex planar mechanisms. The triad is a connected string of three vectors representing jointed rigid links of an actual mechanism. The triad is used as a tool to model an original mechanism topology with a set of simpler components. Each triad is then used to generate a set of “relative precision positions” which, in turn, enables the dimensional synthesis of each triad with well-established motion and path generation techniques for simple four-bar linkages. Two independent derivations of the relative precision positions are provided. All common triad geometries amenable to simple dyad synthesis techniques are presented. The triad geometries summarized here may be applied to two, three, four, and five precision position problems using graphical, algebraic, or complex number formulations of Burmester theory. Examples are provided.


Author(s):  
T. J. Lawley ◽  
R. V. Nambiar ◽  
J. K. Nisbett ◽  
S. Prince ◽  
H. Zarefar

Abstract Burmester’s solution to the problem of guiding a body through four precision points has been extended to find planar mechanisms that have their pivots located inside prescribed regions. The complex number formulation has been used to generate the Burmester curves. A random search technique was developed to choose a new set of precision points that lie within user specified limits, in order to find a set of curves that pass through the desired regions. A computer program was written to generate Burmester curves that lie within the desired regions, while maintaining a coupler motion within satisfactory limits. An automobile suspension linkage was successfully designed using this program.


Author(s):  
A. F. Beardon

AbstractThe unwinding number of a complex number was introduced to process automatic computations involving complex numbers and multi-valued complex functions, and has been successfully applied to computations involving branches of the Lambert W function. In this partly expository note we discuss the unwinding number from a purely topological perspective, and link it to the classical winding number of a curve in the complex plane. We also use the unwinding number to give a representation of the branches $$W_k$$ W k of the Lambert W function as a line integral.


1985 ◽  
Vol 99 ◽  
pp. 11-30 ◽  
Author(s):  
Shigeyuki Kondo

A degeneration of K3 surfaces (over the complex number field) is a proper holomorphic map π: X→Δ from a three dimensional complex manifold to a disc, such that, for t ≠ 0, the fibres Xt = π-1(t) are smooth K3 surfaces (i.e. surfaces Xt with trivial canonical class KXt = 0 and dim H1(Xt, Oxt) = 0).


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