Immobility;
Grasp;
Fixturing;
Wrench;
Form closure;
Second-order immobility;
Positive basis;
D O I:
暂无
中图分类号:
学科分类号:
摘要:
We study the output-sensitive computation of all the combinations of
edges and concave vertices of a simple polygon that allow an immobilizing
grasp with less than four frictionless point contacts.
More specifically, if n is the number of edges, and m is the number of
concave vertices of the polygon, we show how to compute:
in O(m4/3 log1/3 m + K) time, all K combinations
that allow a form-closure grasp with two contacts;
in O(n2 log4 m + K) time, all K combinations
that allow a form-closure grasp with three contacts;
in O(n log4 m + (nm)2/3 log2+ε m + K) time (for any constant ε > 0), all K combinations of one concave vertex and one edge
that allow a grasp with one contact on the vertex and one contact on the interior of the edge, satisfying Czyzowicz's weaker conditions for immobilization; in O(n2 log3 n + K) time, all K combinations of three edges that allow a grasp with one contact on the interior of each edge, satisfying Czyzowicz's weaker conditions for immobilization.