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A new variable damping semiactive device for seismic response reduction of civil structures

JOURNAL OF MECHANICS OF MATERIALS AND STRUCTURES 2007年第8期2卷 1639-1656页

作者： Cundumi, Orlando Suarez, Luis E. Caribbean Univ Dept Engn Bayamon PR 00960 USA Univ Puerto Rico Dept Civil Engn Mayaguez PR 00681 USA

A semiactive mechanism, called a VDSA (variable damping semiactive device), is proposed to reduce the seismic response of structures. It is composed of two fixed-orifice viscous fluid dampers installed in the form of a V whose top ends are attached to a floor and their lower ends to a collar that moves along a vertical rod. By varying the VDSA position one obtains an optimal instantaneous damping added to the structure. The position of the moving end is calculated with an algorithm based on a variation of the instantaneous optimal control theory which includes a generalized LQR (linear quadratic regulator) scheme. This modified algorithm, referred to as Qv, is based on the minimization of a performance index J quadratic in the state vector, the control force vector, and an absolute velocity vector. Two variants of the algorithm are used to present numerical simulations of the controlled seismic response of a single and a MDOF (multi-degree-of-freedom) structure.

关键词： semiactive systems control algorithms earthquake engineering seismic response added damping

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Assistive robotic arm: Evaluation of the performance of intelligent algorithms

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ASSISTIVE TECHNOLOGY 2021年第2期33卷 95-104页

作者： Lebrasseur, Audrey Lettre, Josiane Routhier, Francois Archambault, Philippe S. Campeau-Lecours, Alexandre Univ Laval Dept Rehabil Quebec City PQ Canada Ctr Integre Univ Sante & Serv Sociaux Capitale Na Inst Readaptat Deficience Phys Quebec Ctr Interdisciplinary Res Rehabil & Social Integr Quebec City PQ Canada Ctr Integre Sante & Serv Sociaux Laval Interdisciplinary Res Ctr Rehabil Laval PQ Canada McGill Univ Sch Phys & Occupat Therapy Montreal PQ Canada Univ Laval Dept Mech Engn Quebec City PQ Canada

People with upper body disabilities may be limited in their activities of daily living. Robotic arms, such as JACO, are assistive devices that could improve their abilities, independent living, and social participation. However, performing complex tasks with JACO can be time-consuming or tedious. Therefore, some advanced functionalities have been developed to enhance the performance of users. The main objective of this study is to evaluate the performance, in terms of ease of use, task completion time, and participants' perception of usability, of three new algorithms applied to the JACO robotic arm: (1) predefined position, (2) fluidity filter, and (3) drinking mode. The secondary objective is to evaluate differences in performance variables between proportional and non-proportional control modes. Fourteen participants with upper body disabilities completed various tasks with and without these functionalities. Using JACO with the algorithms led to a significant decrease of up to 72% in task completion time and improvements of 2.3 and 2.9 on a 7-point Likert scale for perceived ease of use and usability, respectively. There was no significant difference between control modes. Our results demonstrate that algorithms could produce significant improvements in performing daily living activities.

关键词： assistive devices assistive robotic arms control algorithms rehabilitation

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Four-Joint Redundant Wrist Mechanism and Its control

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JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND control-TRANSACTIONS OF THE ASME 1989年第2期111卷 200-204页

作者： Yoshikawa, Tsuneo Kiriyama, Shigeo Kyoto Univ Automat Res Lab Uji Kyoto 611 Japan

It is known that conventional three-joint wrists of robot manipulators have two conical regions of degeneracy in which the ability of the wrist to orient the end-effector is poor, A four-joint wrist mechanism is proposed in this paper as a means of overcoming this degeneracy problem. The manipulating ability of this wrist with respect to the end-effector orientation is analyzed using the manipulability measure. A pseudoinverse control algorithm for this redundant wrist mechanism is developed and its effectiveness is shown by experiments.

关键词： End effectors Manipulators control algorithms

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A DIRECT DIGITAL-control ALGORITHM FOR control OF A SINGLE ENVIRONMENTAL SPACE

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JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND control-TRANSACTIONS OF THE ASME 1985年第4期107卷 324-331页

作者： CHERCHAS, DB ABDELMESSIH, A TOWNSEND, M UNIV TORONTO DEPT MECH ENGNTORONTO M5S 1A4ONTARIOCANADA UNIV VIRGINIA DEPT MECH & AEROSP ENGNCHARLOTTESVILLEVA 22903

A direct digital control algorithm for control of dry bulb temperature in a single environmental space is developed. The algorithm is based on a bilinear mathematical model, developed in the paper, of the response of the space dry bulb temperature and moisture content. The algorithm is somewhat unique in that it includes feedback and feedforward terms in a manner respecting the bilinear nature of the controlled process and as well, minimizes a practical performance index. The discrete time form of the algorithm is presented and simulation results given.

关键词： control algorithms algorithms Temperature Feedback Feedforward control Simulation results

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Local voltage control in distribution networks using PI control of active and reactive power

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ELECTRIC POWER SYSTEMS RESEARCH 2022年 212卷

作者： Lundberg, Martin Samuelsson, Olof Hillberg, Emil Lund Univ Ind Elect Engn & Automat Lund Sweden RISE Res Inst Sweden Elect Power Syst Gothenburg Sweden

Overvoltage is becoming increasingly prevalent in distribution networks with high penetration of renewable distributed energy sources (DERs). Local control of converter-based resources is a flexible and scalable method to prevent this growing issue. Reactive power is used for voltage control in many local control schemes. However, the typical range of R/X ratios for distribution power lines indicates that mitigation of overvoltage often requires excessive amounts of reactive power. Complete reliance on reactive power thus limits the effectiveness of local control strategies. In this work we instead propose a method that combines enhanced power factor voltage control with upper voltage limit tracking using PI control. We develop a modelling framework and demonstrate the stability of the proposed method. We then simulate the nonlinear operation of two parallel PI controllers in a medium voltage test system.

关键词： Distribution networks control algorithms Local voltage control Stability analysis

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Fractional-Order control Algorithm for Tello EDU Quadrotor Drone Safe Landing during Disturbance on Propeller

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DRONES 2024年第10期8卷 566-566页

作者： Rosmadi, Nurfarah Hanim Binti Bingi, Kishore Devan, P. Arun Mozhi Korah, Reeba Kumar, Gaurav Prusty, B. Rajanarayan Omar, Madiah Univ Teknol PETRONAS Dept Elect & Elect Engn Seri Iskandar 31750 Malaysia Alliance Univ Alliance Coll Engn & Design Dept Elect & Commun Engn Bangalore 562106 India Galgotias Univ Sch Engn Dept Elect Elect & Commun Engn Greater Noida 203201 India Univ Teknol PETRONAS Dept Chem Engn Seri Iskandar 31750 Malaysia

Quadcopter drones have become increasingly popular because of their versatility and usefulness in various applications, such as surveillance, delivery, and search and rescue operations. Weather conditions and obstacles can undoubtedly pose challenges for drone flights, sometimes causing the loss of one or two propellers. This is a significant challenge as the loss of one or more propellers leads to a sudden loss of control, potentially resulting in a crash, which must be addressed through advanced control strategies. Therefore, this article develops and implements a fractional-order control algorithm to enhance quadrotor drones' safety and resilience during propeller failure scenarios. The research encompasses the complexities of quadrotor dynamics, fractional-order control theory, and existing methodologies for ensuring safe drone landings. The study emphasizes case validation on experimental results, where four distinct cases were tested using PID and Fractional-order PID (FOPID) controllers. These cases involve various simulated failure conditions to assess the performance and adaptability of the developed control algorithms. The results show the proposed FOPID control's superior robustness and adaptability compared to traditional PID controllers. These offer significant advancements in navigating dynamic environments and managing disruptive elements introduced during propeller failure simulations in drone control technology.

关键词： quadrotor drones fractional-order PID controller propeller failure drone safety control algorithms

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Time-delay sliding mode control for a servo

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JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND control-TRANSACTIONS OF THE ASME 1999年第1期121卷 143-148页

作者： Park, JH Kim, YM Hanyang Univ Sch Mech Engn Seoul 133791 South Korea

In this paper, a new control algorithm called the time-delay sliding mode control (TDSMC), based on the time delay control (TDC) and the integral sliding mode control (SMC), is proposed and applied for controlling DC servos with a seal installed on their rotating axes. This algorithm adopts the robustness of sliding model control and improves the robustness of the TDC. The results of a series of experiments on a DC servo motor system with stick-slip friction show TDSMC is compatable with the TDC in the nominal performance, but is superior to the TDC and the PID control in the performance robustness. Settling time is used as a measure of the performance.

关键词： Stick-slip Delays Friction Robustness control algorithms Time delay systems Servomotors Sliding mode control Servomechanisms algorithms

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A STOCHASTIC REGULATOR FOR INTEGRATED COMMUNICATION AND control-SYSTEMS .1. FORMULATION OF control LAW

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JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND control-TRANSACTIONS OF THE ASME 1991年第4期113卷 604-611页

作者： LIOU, LW RAY, A PENN STATE UNIV DEPT MECH ENGNUNIV PKPA 16802

Integrated Communication and control Systems (ICCS), recently introduced and analyzed in a series of papers [1-7], are applicable to complex dynamical processes like advanced aircraft, spacecraft, automotive, and manufacturing processes. Time-division-multiplexed computer networks are employed in ICCS for exchange of information between spatially distributed plant components as well as for coordination of the diverse control and decision-making functions. Unfortunately, an ICCS network introduces randomly varying, distributed delays within the feedback loops in addition to the digital sampling and data processing delays. These network-induced delays degrade the system dynamic performance, and are a source of potential instability. This two-part paper presents the synthesis and performance evaluation of a stochastic optimal control law for ICCS. In this paper, which is the first of two parts, a state feedback control law for ICCS has been formulated by using the dynamic programming and optimality principle on a finite-time horizon. The control law is derived on the basis of a stochastic model of the plant which is augmented in state space to take into account the effects of randomly varying delays in the feedback loop. The second part [8] presents numerical analysis of the control law and its performance evaluation by simulation of the flight dynamic model of an advanced aircraft.

关键词： Dynamic programming Delays Flight Simulation Aircraft State feedback control algorithms control systems Simulation results Numerical analysis Dynamic models

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DISCRETE-TIME INVERSE DYNAMICS control OF FLEXIBLE JOINT ROBOTS

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JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND control-TRANSACTIONS OF THE ASME 1992年第2期114卷 229-233页

作者： JANKOWSKI, KP VANBRUSSEL, H Katholieke Universiteit Leuven Department of Mechanical Engineering B-3030 Leuven Belgium

This paper focuses on the problem of the application of inverse dynamics control methods to robots with flexible joints and electromechanical actuators. Due to drawbacks of the continuous-time inverse dynamics, discussed in the paper, a new control strategy in discrete-time is presented. The proposed control algorithm is based on numerical methods conceived for the solution of index-three systems of differential-algebraic equations. The method is computationally efficient and admits low sampling frequencies. The results of numerical experiments confirm the advantages of the designed control algorithm.

关键词： Electromechanical actuators Dynamics (Mechanics) control algorithms Numerical analysis Algebra Robots

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Application of Fuzzy Sets in Elevator System control

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IFAC Proceedings Volumes 1996年第7期29卷 143-148页

作者： Nadja Hvala Vladimir Jovan J. Stefan Institute Jamova 39 61111 Ljubljana

The paper considers the elevator group control problem which is actual in large premises where a group of co-ordinated cars is necessary to serve the transport of passengers. Efficient elevator control requires low passenger waiting and transport times, together with low energy consumption, under different traffic conditions. In the paper two algorithms based on fuzzy sets are proposed to perform this task. The first algorithm acts as a “soft switch” between two classical algorithms, each covering a specific traffic situation. The second algorithm is entirely based on fuzzy sets and is appropriate for all situations. The performance of the algorithms in tested case studies gave promising results so that the algorithms will be additionally tested, optimised and statistically evaluated in different case studies.

关键词： Fuzzy control control algorithms supervisory control traffic control

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