The Finite Screw System Associated With the Spatial RPRP Overconstrained Linkage

2004 ◽  
Author(s):  
Chintien Huang ◽  
Han-Tsung Tu
Keyword(s):  
Closed Loop ◽  
Second Order ◽  
Numerical Example ◽  
Finite Displacement ◽  
Prismatic Joints

The spatial RPRP linkage is a closed-loop linkage composed of two revolute and two prismatic joints. It is an overconstrained linkage, which does not obey the Gru¨bler criteria. This paper investigates the finite displacement of the RPRP linkage and shows that all possible finite displacement screws of the coupler link form a screw system of the second order. This paper explores two configurations of the RPRP linkages, folded and unfolded. The screw systems for both types of RPRP linkage are obtained by intersecting two 3-systems corresponding to the RP and PR dyads. A numerical example is provided to verify the result.

Analysis of Reset Control Systems Consisting of a FORE and Second-Order Loop1

2001 ◽  
Vol 123 (2) ◽  
pp. 279-283 ◽  
Author(s):  
Qian Chen ◽  
Yossi Chait ◽  
C. V. Hollot
Keyword(s):  
Control Systems ◽  
Closed Loop ◽  
Second Order ◽  
Step Response ◽  
Steady State Response ◽  
First Order ◽  
State Response ◽  
Loop Transfer Function ◽  
Performance Specifications ◽  
Reset Control

Reset controllers consist of two parts—a linear compensator and a reset element. The linear compensator is designed, in the usual ways, to meet all closed-loop performance specifications while relaxing the overshoot constraint. Then, the reset element is chosen to meet this remaining step-response specification. In this paper, we consider the case when such linear compensation results in a second-order (loop) transfer function and where a first-order reset element (FORE) is employed. We analyze the closed-loop reset control system addressing performance issues such as stability, steady-state response, and transient performance.

An Investigation of Screw Systems in the Finite Displacements of Bennett-Based 6R Linkages

1999 ◽  
Vol 122 (4) ◽  
pp. 426-430 ◽  
Author(s):  
Chintien Huang ◽  
Chi-Chih Sun
Keyword(s):  
Numerical Simulations ◽  
Second Order ◽  
Finite Displacement ◽  
Finite Displacements ◽  
Overconstrained Linkages

This paper investigates, via numerical simulations, the finite displacements of all the known Bennett-based 6R overconstrained linkages: Goldberg’s 6R, variant Goldberg 6R, Waldron’s hybrid 6R, and Wohlhart’s hybrid 6R linkages. An investigation of the finite displacements of nine distinct linkages reveals that every Bennett-based 6R linkage, except for the isomerization of Wohlhart’s hybrid linkage, inherits the linear properties of the Bennett mechanism. The relative finite displacement screws of some non-adjacent links of these linkages form screw systems of the second order. Thirty-one screw systems are reported in this paper. [S1050-0472(00)02204-2]

scholarly journals Nondifferentiable G-Mond–Weir Type Multiobjective Symmetric Fractional Problem and Their Duality Theorems under Generalized Assumptions

Symmetry ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1348 ◽  
Author(s):  
Ramu Dubey ◽  
Lakshmi Narayan Mishra ◽  
Luis Manuel Sánchez Ruiz
Keyword(s):  
Vector Optimization ◽  
Optimization Problem ◽  
Vector Optimization Problem ◽  
Second Order ◽  
Type Model ◽  
Dual Model ◽  
Duality Theorems ◽  
Converse Duality ◽  
Numerical Example ◽  
Primal Dual

In this article, a pair of nondifferentiable second-order symmetric fractional primal-dual model (G-Mond–Weir type model) in vector optimization problem is formulated over arbitrary cones. In addition, we construct a nontrivial numerical example, which helps to understand the existence of such type of functions. Finally, we prove weak, strong and converse duality theorems under aforesaid assumptions.

scholarly journals Second-Order Multiagent Systems with Event-Driven Consensus Control

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Jiangping Hu ◽  
Yulong Zhou ◽  
Yunsong Lin
Keyword(s):  
Multiagent Systems ◽  
Closed Loop ◽  
Second Order ◽  
Multi Agent System ◽  
Consensus Control ◽  
Agent System ◽  
Control Laws ◽  
Event Driven ◽  
Multi Agent ◽  
Event Times

Event-driven control scheduling strategies for multiagent systems play a key role in future use of embedded microprocessors of limited resources that gather information and actuate the agent control updates. In this paper, a distributed event-driven consensus problem is considered for a multi-agent system with second-order dynamics. Firstly, two kinds of event-driven control laws are, respectively, designed for both leaderless and leader-follower systems. Then, the input-to-state stability of the closed-loop multi-agent system with the proposed event-driven consensus control is analyzed and the bound of the inter-event times is ensured. Finally, some numerical examples are presented to validate the proposed event-driven consensus control.

A New Controller of Stochastic Delay Systems

2011 ◽  
Vol 63-64 ◽  
pp. 974-977
Author(s):  
Yun Chen ◽  
Qing Qing Li
Keyword(s):  
Time Delay ◽  
Closed Loop ◽  
Stochastic Systems ◽  
Delay Systems ◽  
Mean Square ◽  
Closed Loop System ◽  
Stochastic Delay ◽  
Numerical Example ◽  
Mean Square Stability ◽  
Delay Dependent

By introducing an additional vector, a new delay-dependent controller is designed for stochastic systems with time delay in this paper. The presented controller is formulated by means of LMI, and it guarantees robust asymptotical mean-square stability of the resulting closed-loop system. Our result shows advantage over some existing ones, which is demonstrated by a numerical example.

scholarly journals Torque control of bolt tightening process through adaptive-gain second-order sliding mode

2020 ◽  
Vol 53 (7-8) ◽  
pp. 1131-1143
Author(s):  
Zhimin Wu ◽  
Guigang Zhang ◽  
Wenjuan Du ◽  
Jian Wang ◽  
Fengyang Han ◽  
...  
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Sliding Mode ◽  
Nonlinear Process ◽  
Second Order ◽  
Torque Control ◽  
Sliding Mode Controller ◽  
Tightening Torque ◽  
Bolt Preload ◽  
Second Order Sliding Mode

Bolts constitute a very important subset of mechanical fasteners. In order to tighten bolts, a degree of bolt preload scatter is to be expected. Since the torque control of tightening bolts is the most popular means of controlling the preload, an appropriate tightening torque becomes pivotal. This paper investigates the torque control problem of bolt tightening process. This process is not as simple as it looks because the inherently nonlinear process contains many uncertainties. To conquer the adverse effects of the uncertainties, this paper designs an adaptive-gain second-order sliding mode controller. Theoretically, such design can guarantee that the bolt tightening process has the closed-loop stability in the sense of Lyapunov. From the aspect of practice, the control method is carried out by a platform. Some comparisons illustrate the feasibility and effectiveness of the designed controller.

Analysis of Barriers to Control of Manipulators Within Accessible Output Sets

1995 ◽  
Author(s):  
Edward J. Haug ◽  
Frederick A. Adkins ◽  
Chaoxin Charles Qiu ◽  
Jeng Yen
Keyword(s):  
Quadratic Forms ◽  
Closed Loop ◽  
Position Control ◽  
Quantitative Information ◽  
Second Order ◽  
Velocity Control ◽  
Unilateral Constraints ◽  
Open Chain ◽  
Output Control ◽  
Curves And Surfaces

Abstract Barriers to output control of manipulators, both in the interior and at the boundary of accessible output sets, are analyzed using first and second order Taylor approximations of the output in selected directions as functions of manipulator input. The formulation is valid for both planar and spatial manipulators, with open chain and closed loop structures, and accounts for the effects of unilateral constraints on the range of admissible control inputs. Criteria defining curves and surfaces associated with singular output control of manipulators are extended to define normals to such curves and surfaces. It is shown that output velocity in the direction normal to such curves and surfaces must be zero, so they arc barriers to velocity control in the associated manipulator configuration. Second order Taylor expansion of normal output with respect to input parameters yields quantitative information regarding barriers to output position control. Definiteness properties of the resulting quadratic approximation define directions of admissible and inadmissible outputs. Algorithms for automatically computing the associated quadratic forms and eigenvalues that determine their definiteness properties are presented and illustrated using planar examples.

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