Active Balancing of a Flexible Linkage With Redundant Drives

2003 ◽  
Vol 125 (1) ◽  
pp. 119-123 ◽  
Author(s):  
Yue-Qing Yu ◽  
Jing Lin
Keyword(s):  
Active Control ◽  
Dynamic Equations ◽  
Dynamic Balancing ◽  
Active Balancing ◽  
Redundant Actuators ◽  
First Time ◽  
Flexible Mechanisms ◽  
Flexible Linkage ◽  
Shaking Moment

The dynamic balancing of flexible linkages, which is a challenging topic in the dynamics of mechanisms, is accomplished by active control with redundant drives for the first time in the present study. The mathematical modal and dynamic equations of flexible mechanisms with redundant actuators are derived. The optimum shaking force and shaking moment balancing of a flexible linkage have been obtained through an active way of additional actuators. The effectiveness and advantage of redundant drives on the dynamic balancing of flexible mechanisms is fully demonstrated by an example of four-bar linkages.

Active Control for the Complete Dynamic Balancing of Linkages

1992 ◽  
Author(s):  
Jorge Angeles ◽  
Meyer A. Nahon ◽  
Thomas Thümmel
Keyword(s):  
Active Control ◽  
Degree Of Freedom ◽  
Dynamic Balancing ◽  
Reaction Forces ◽  
The Masses ◽  
Inertia Forces ◽  
Shaking Moment

Abstract This paper deals with the dynamic balancing of linkages. For one-degree-of-freedom linkages, this task consists of eliminating both the shaking moment and the shaking force exerted by the inertia forces of the moving links on the frame. While the latter can be eliminated by properly deciding on both the location of the mass centers and the ratios of the masses and link lengths involved, the shaking moment due to these forces cannot be eliminated in this way. Indeed, the elimination of the shaking force is attained by having the two transmitted forces cancel each other, although each individual force does not necessarily vanish, thereby still producing a shaking moment. In this paper, we propose the use of redundant motors in order to eliminate the reaction forces transmitted to the base, thereby also eliminating the shaking moment due to these forces. However, the net moment acting on the frame is shown to be unaltered by this technique.

scholarly journals Li–Yorke Chaos in Hybrid Systems on a Time Scale

2015 ◽  
Vol 25 (14) ◽  
pp. 1540024 ◽  
Author(s):  
Marat Akhmet ◽  
Mehmet Onur Fen
Keyword(s):  
Differential Equations ◽  
Hybrid Systems ◽  
Time Scales ◽  
Time Scale ◽  
Impulsive Differential Equations ◽  
Reduction Technique ◽  
Duffing Equation ◽  
Dynamic Equations ◽  
Definition Of ◽  
First Time

By using the reduction technique to impulsive differential equations [Akhmet & Turan, 2006], we rigorously prove the presence of chaos in dynamic equations on time scales (DETS). The results of the present study are based on the Li–Yorke definition of chaos. This is the first time in the literature that chaos is obtained for DETS. An illustrative example is presented by means of a Duffing equation on a time scale.

Mass Flow and Derivative Moment of Inertia Flow in Planar (Geared) Linkages

1992 ◽  
Author(s):  
Zhonghe Ye ◽  
M. R. Smith
Keyword(s):  
Mass Flow ◽  
Kinematic Analysis ◽  
Moment Of Inertia ◽  
Force Balance ◽  
New Concepts ◽  
Prismatic Joints ◽  
Planar Linkages ◽  
First Time ◽  
Shaking Moment

Abstract The paper describes a method for the determination of the conditions for the complete shaking force and shaking moment balancing of planar linkages, including geared linkages, with revolute and prismatic joints. The conditions may be written down without the need for any kinematic analysis of the linkage by the application of two new concepts. These are the concept of mass flow for complete shaking force balance and the concept of derivative moment of inertia flow for complete shaking moment balance, the second of which is described here for the first time. A number of examples demonstrate the power of the method.

scholarly journals Fault-Structure-Based Active Fault Diagnosis: A Geometric Observer Approach

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4475
Author(s):  
Zhao Zhang ◽  
Xiao He
Keyword(s):  
Fault Diagnosis ◽  
Active Fault ◽  
Geometric Approach ◽  
Dynamic Equations ◽  
Fault Structure ◽  
Numerical Example ◽  
Input And Output ◽  
Incipient Faults ◽  
First Time ◽  
New Framework

Fault diagnosis techniques can be classified into passive and active types. Passive approaches only utilize the original input and output signals of the system. Because of the small amplitudes, the characteristics of incipient faults are not fully represented in the data of the system, so it is difficult to detect incipient faults by passive fault diagnosis techniques. In contrast, active methods can design auxiliary signals for specific faults and inject them into the system to improve fault diagnosis performance. Therefore, active fault diagnosis techniques are utilized in this article to detect and isolate incipient faults based on the fault structure. A new framework based on observer approach for active fault diagnosis is proposed and the geometric approach based fault diagnosis observer is introduced to active fault diagnosis for the first time. Based on the dynamic equations of residuals, auxiliary signals are designed to enhance the diagnosis performance for incipient faults that have specific structures. In addition, the requirements that auxiliary signals need to meet are discussed. The proposed method can realize the seamless combination of active fault diagnosis and passive fault diagnosis. Finally, a numerical example is presented to demonstrate the effectiveness of the proposed approach, and it is indicated that the proposed method significantly improves the accuracy of the diagnosis for incipient faults.

Local-periodic solutions for functional dynamic equations with infinite delay on changing-periodic time scales

2018 ◽  
Vol 68 (6) ◽  
pp. 1397-1420 ◽  
Author(s):  
Chao Wang ◽  
Ravi P. Agarwal ◽  
Donal O’Regan
Keyword(s):  
Periodic Solutions ◽  
Time Scales ◽  
Time Scale ◽  
Infinite Delay ◽  
Sufficient Conditions ◽  
Dynamic Equations ◽  
Krasnoselskii’S Fixed Point Theorem ◽  
Arbitrary Time ◽  
First Time ◽  
Composition Theorem

Abstract In this paper, by using the concept of changing-periodic time scales and composition theorem of time scales introduced in 2015, we establish a local phase space for functional dynamic equations with infinite delay (FDEID) on an arbitrary time scale with a bounded graininess function μ. Through Krasnoseľskiĭ’s fixed point theorem, some sufficient conditions for the existence of local-periodic solutions for FDEID are established for the first time. This research indicates that one can extract a local-periodic solution for dynamic equations on an arbitrary time scale with a bounded graininess function μ through some index function.

scholarly journals Antisynchronization of Nonidentical Fractional-Order Chaotic Systems Using Active Control

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Sachin Bhalekar ◽  
Varsha Daftardar-Gejji
Keyword(s):  
Active Control ◽  
Fractional Order ◽  
Chaotic Systems ◽  
Control Method ◽  
Value Of Time ◽  
State Variables ◽  
Financial Systems ◽  
The Stability ◽  
First Time ◽  
Active Control Method

Antisynchronization phenomena are studied in nonidentical fractional-order differential systems. The characteristic feature of antisynchronization is that the sum of relevant state-variables vanishes for sufficiently large value of time variable. Active control method is used first time in the literature to achieve antisynchronization between fractional-order Lorenz and Financial systems, Financial and Chen systems, and Lü and Financial systems. The stability analysis is carried out using classical results. We also provide numerical results to verify the effectiveness of the proposed theory.

scholarly journals On the Boundedness Property of the Inertia Matrix and Skew-Symmetric Property of the Coriolis Matrix for Vehicle-Manipulator Systems

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Pål Johan From ◽  
Ingrid Schjølberg ◽  
Jan Tommy Gravdahl ◽  
Kristin Ytterstad Pettersen ◽  
Thor I. Fossen
Keyword(s):  
Control Theory ◽  
Rigid Bodies ◽  
Dynamic Equations ◽  
State Variables ◽  
Boundedness Property ◽  
Inertia Matrix ◽  
Fixed Base ◽  
First Time ◽  
Symmetric Property ◽  
Future Reference

This paper addresses the boundedness property of the inertia matrix and the skew-symmetric property of the Coriolis matrix for vehicle-manipulator systems. These properties are widely used in control theory and Lyapunov-based stability proofs and thus important to identify. The skew-symmetric property does not depend on the system at hand but on the parameterization of the Coriolis matrix, which is not unique. It is the authors’ experience that many researchers take this assumption for granted without taking into account that several parameterizations exist. In fact, most researchers refer to references that do not show this property for vehicle-manipulator systems but for other systems such as single rigid bodies or fixed-base manipulators. As a result, the otherwise rigorous stability proofs fall apart. In this paper, we list some relevant references and give the correct proofs for some commonly used parameterizations for future reference. Depending on the choice of state variables, the boundedness of the inertia matrix will not necessarily hold. We show that deriving the dynamics in terms of quasi-velocities leads to an inertia matrix that is bounded in its variables. To the best of our knowledge, we derive for the first time the dynamic equations of vehicle-manipulator systems with non-Euclidean joints for which both properties are true.

scholarly journals Motion Constraints and Trajectory Planning of a Planar Active Dynamic Balancing Mechanism

2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Kun Wang ◽  
Ke Li ◽  
Peng Chen ◽  
Qiuju Zhang ◽  
Yi Cao
Keyword(s):  
Dynamic Model ◽  
Collision Avoidance ◽  
Trajectory Planning ◽  
Structural Constraint ◽  
Dynamic Balancing ◽  
Numerical Examples ◽  
Motion Constraints ◽  
Active Balancing ◽  
Normal Trajectory

We propose a new solution to the active balancing issue under mechanical structural constraint. A dynamic model of the 3-DOF active balancer is established considering the limitations of the mechanical construction due to the lengths of the sliding rails. A methodology for the collision-avoidance trajectory planning is presented in addition to the normal trajectory planning to design the collision-free active balancing strategy. Numerical examples are presented to illustrate the effect of the parameter constrains as well as verify the effectiveness and necessity of trajectory planning.

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