An asteroid anchoring method based on cross-drilling geometric force closure of ultrasonic drill

2021 ◽  
Vol 178 ◽  
pp. 813-823
Author(s):  
Tongzhao Wang ◽  
Qiquan Quan ◽  
Mengxue Li ◽  
Jiangchuan Huang ◽  
Zhijun Zhao ◽  
...  
Keyword(s):  
Author(s):  
V. E Zinoviev ◽  

For the third variant of the adaptive friction clutch with a separate force closure, the boundaries of the change in the value of the feedback gain are determined, within which the clutch has the highest accuracy of operation, if its load characteristic is realized in the form of a curve monotonically increasing in the range of the friction coefficient values. A variant of separate power closure is developed, which provides for the introduction of an additional spring into the clutch design in the closure node of the thorn pairs of the main friction group.


2011 ◽  
Vol 08 (04) ◽  
pp. 761-775 ◽  
Author(s):  
ZHIXING XUE ◽  
RUEDIGER DILLMANN

Grasping can be seen as two steps: placing the hand at a grasping pose and closing the fingers. In this paper, we introduce an efficient algorithm for grasping pose generation. By the use of preshaping and eigen-grasping actions, the dimension of the space of possible hand configurations is reduced. The object to be grasped is decomposed into boxes of a discrete set of different sizes. By performing finger reachability analysis on the boxes, the kinematic feasibility of a grasp can be determined. If a reachable grasp is force-closure and can be performed by the robotic arm, its grasping forces are optimized and can be executed. The novelty of our algorithm is that it takes into account both the object geometrical information and the kinematic information of the hand to determine the grasping pose, so that a reachable grasping pose can be found very quickly. Real experiments with two different robotic hands show the efficiency and feasibility of our method.


Author(s):  
B. J. Gilmore ◽  
R. J. Cipra

Abstract Due to changes in the kinematic constraints, many mechanical systems are described by discontinuous equations of motion. This paper addresses those changes in the kinematic constraints which are caused by planar bodies contacting and separating. A strategy to automatically predict and detect the kinematic constraint changes, which are functions of the system dynamics, is presented in Part I. The strategy employs the concepts of point to line contact kinematic constraints, force closure, and ray firing together with the information provided by the rigid bodies’ boundary descriptions, state variables, and reaction forces to characterize the kinematic constraint changes. Since the strategy automatically predicts and detects constraint changes, it is capable of simulating mechanical systems with unpredictable or unforeseen changes in topology. Part II presents the implementation of the characterizations into a simulation strategy and presents examples.


PM&R ◽  
2019 ◽  
Vol 11 (S1) ◽  
Author(s):  
Andry Vleeming ◽  
Mark Schuenke

Author(s):  
Marc Gouttefarde

The pose of the mobile platform of a parallel cable-driven robot is said to be fully constrained if any wrench can be created at the platform by pulling on it with the cables. A fully constrained pose is also known as a force-closure pose. In this paper, a review of three useful characterizations of a force-closure pose is proposed. These characterizations are stated in the form of theorems for which proofs are presented. Tools from linear algebra allow to derive some of these proofs while the others are more difficult and can hardly be obtained in this manner. Therefore, polyhedral cones, which are special cases of convex cones, are introduced along with some of their well-known fundamental properties. Then, it is shown how the aforementioned difficult proofs can be obtained as direct consequences of these properties.


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