@article{907.53008, title = {{Equiform bundle motions in $E_3$ with spherical trajectories. I.}}, author = {Anton Gfrerrer and Johann Lang}, journal = {Beitr. Algebra Geom.}, number = {2}, pages = {307-316}, volume = {39}, year = {1998}, biburl = {http://www.bibsonomy.org/bibtex/2921a6c7fe9bae86c2006ac6d67ea2484/dmartins}, description = {robotica-bib}, abstract = {In 1906 and 1908 Bricard and Borel published two long papers in which they determined Euclidean motions with spherical trajectories [{\it R. Bricard}, J. l'Ecole Polytechnique, II. Ser. 11, 1-93 (1906; JFM 37.0705.04); {\it E. Borel}, Mem. Sav. Etrangers, Paris 33, 1-128 (1908; JFM 39.0749.02)]. Based on these papers the authors determine equiform bundle motions which have spherical trajectories. They introduce a 10-dimensional parameter space $P(W)$ in which a 6-dimensional surface $B_6$ represents the condition that a point remains on a sphere during an equiform motion. Furthermore, an embedding of the motion group into a 10-dimensional projective space $P(V)$ is used to give an interpretation of the sphere condition as an orthogonality relation between the points of $P(V)$ and $P(W)$. It is shown that the images of sphere conditions given by any motion are on a linear intersection of $B_6$. Because of this fact, linear subspaces of $P(W)$ and their intersection with $B_6$ are studied. The case that a line is contained in $B_6$ results in either one point having a circle as trajectory or the points of a circle or a line of the moving system are constrained to move on spheres or in planes. The case of the intersection of a 2-dimensional linear space with $B_6$ yields a one parameter motion which moves the points of a bundle plane on spherical trajectories. \par [For Part II, see the following review Zbl 907.53009]. }, reviewer = {M.Husty (Leoben)}, language = {English}, classmath = {*53A17 Kinematics (differential geometry)}, keywords = {bundle equiform motion; of principle spherical trajectories; transference } }