The motivation of our current research is to devise motion planners for legged locomotion that are able to exploit the robot’s actuation capabilities. This means, when possible, to minimize joint torques or to propel as much as admissible when required. For this reason we define two new 6-dimensional bounded polytopes that we name Actuationconsistent Wrench Polytope (AWP) and Feasible Wrench Po...

We build on previous works advocating the use of the Gravito-Inertial Wrench Cone (GIWC) as a general contact stability criterion (a “ZMP for non-coplanar contacts”). We show how to compute this wrench cone from the friction cones of contact forces by using an intermediate representation, the surface contact wrench cone, which is the minimal representation of contact stability for each surface ...

In lathe operation, the most frequently used wrenches are chuck and tool holder wrenches, which different in structure function cannot be replaced, forgetting to remove will cause safety accidents. To solve above problems, this paper designs a new type of wrench, integrates functions wrench various screwdrivers, can easily change form by certain improves production efficiency eliminates hazards.

Force-closure is a fundamental topic in grasping research. Relevant problems include force-closure test, quality evaluation, and grasp planning. Implementing the well-known force-closure condition that the origin of the wrench space lies in the interior of the convex hull of primitive wrenches, Liu presented a ray-shooting approach to forceclosure test. Because of its high efficiency in 3D work...

An ensemble of screws is known as a screw system, and is deened by a set of n 6 independent basis screws. The order of a screw system is equal to the number of basis screws required to deene it; such a system is also called an n-system. The order of a screw system reciprocal to an n-system is (6 ? n). With an innnitesimal rigid motion of an object in three-dimensional Euclidean space there is a...

space 1 The space of twist Joint space The space of wrench (6) jT T T J ~ ( = J KI Ii) I ' * 1 v torque space 1 Figure 2.6: Transformation from Task Domain to Joint Domain where each column of J is the image in abstract space of the corresponding column of the Jacobian J . Thus. the base of the joint variable space is: and the base of the joint torque space is: Because J is a matrix defined in ...