EUDML

There exist many examples of closed kinematical chains which have a freedom of motion, but there are very few systematical results in this direction. This paper is devoted to the systematical treatment of 4-parametric closed kinematical chains and we show that the so called Bennet’s mechanism is essentially the only 4-parametric closed kinematical chain which has the freedom of motion. According to [3] this question is connected with the problem of existence of asymptotic geodesic lines on robot-manipulators...

Similarity motions in $E_{3}$ with plane trajectories

Adolf Karger — 1981

Aplikace matematiky

In this paper the author finds and describes all similarity space motions, which have only plane trajectories of points. All such motions are explicitly expressed. They are of 5 types, all of them cylindrical. Trajectories are conic sections (3 types) or arbitrary plane curves (2 types).

Euclidean space motions with affinely equivalent trajectories

Adolf Karger — 1983

Aplikace matematiky

The author studies the Euclidean space motions with the property that the trajectory of every point is an affine image of a given space curve. Such motions split into plane motions and translations and their trajectories are cylindrical curves. They are characterized as motions with the following property: Not all trajectories are plane curves and if any trajectory has a planar point, it lies in a plane. Motions with infinitely many straight trajectories form a special subclass of those motions....

Classification of projective space motions with only plane trajectories

Adolf Karger — 1989

Aplikace matematiky

The paper contains the solution of the classification problem for all motions in the complex projective space, which have only plane trajectories. It is shown that each such motion is a submanifold of a maximal motion with the same property. Maximal projective space motions with only plane trajectories are determined by special linear submanifolds of dimensions 2, 3, 5, 8 in $G L (4, C)$ , they are denoted as $R, E_{1}, . . ., E_{6}, S_{1}, S_{2}$ and given by explicit expressions.

The Darboux theorem on plane trajectories of two-parametric space motions

Adolf Karger — 1988

Aplikace matematiky

The paper contains the proof of the classification theorem for two-parametric space motions with at least 5 points with plane trajectories. The proof is based on [1] and on the cannonical form of a certain tensor of order 3. The second part of the paper deals with the problem of plane trajectories from the differential-geometrical point of view. Some applications are given.

Projective plane motions with infinitely many straight trajectories

Adolf Karger — 1985

Aplikace matematiky

The paper deals with one-parametric projective plane motins with the property that all points of the inflexion cubic have straight trajectories. It is shown that such motions have in the general case projective equivalent trajectories and that the inflexion cubic is in general irreducible. The cases of the above mentioned motions with reducible inflexion cubic are discussed in detail. The connection with the Darboux property is also mentioned.

Two-parametric motions in $E_{3}$

Adolf Karger — 1987

Aplikace matematiky

The paper deals with the local differential geometry of two-parametric motions in the Euclidean space. The first part of the paper contains contemporary formulation of classical results in this area together with the connection to the elliptical differential geometry. The remaining part contains applications. Necessary and sufficient conditions for splitting of a two-parametric motion into a product of two one-parametric motions, characterization of motions with constant invariants and some others....

Grundlagen der räumlichen kinematischen Geometrie. II

Adolf Karger — 1980

Aplikace matematiky

Der Artikel ist eine Vorsetzung des ersten Teiles des Artikels und ist der Analyse und der Synthese der helikoidalen Bewegungen gewidmet. Im der Analyse der helikoidalen Bewegungen gewidmeten Teil sind die helikoidale Bewegungen als die Zweischraubenbewegungen charakterisiert und es sind die Invarianten der helikoidalen Bewegungen gefunden. Im, der Synthese der helikoidalen Bewegungen gewiemeten, Teil sind alle helikoidalen Bewegungen, die eine ebene oder gerade oder sphärische Punkttrajektorie...