scholarly journals JOINT DESIGN FOR A HYPER-REDUNDANT SERIAL MANIPULATOR

2011 ◽  
Author(s):  
Mark Alonso ◽  
Mark Stephenson ◽  
Afaan Naqvi
Keyword(s):  
Low Cost ◽  
Open Loop ◽  
Relay System ◽  
Joint Design ◽  
Control Signals ◽  
Power And Control ◽  
Duty Cycles ◽  
Control Scheme ◽  
Helical Coils ◽  
And Control

We propose a joint design for a low-cost, light-weight, hyper-redundant serial manipulator. The proposed design consists of two rigid end plates connected by a universal joint; two sets of agonist/antagonist linear actuator pairs allow independent 2-DOF control. In tethered configuration, power and control signals are delivered to the robot by wire; the proposed control scheme is an open-loop relay system. The actuators consist of approximately helical coils of shape memory alloy wire. Current is alternately directed (at a frequency of 10Hz) through the members of each actuator pair; joint deflection is achieved by varying the respective duty cycles.

scholarly journals Semi-Active Magnetic Levitation System for Education

2021 ◽  
Vol 11 (12) ◽  
pp. 5330
Author(s):  
Gisela Pujol-Vázquez ◽  
Alessandro N. Vargas ◽  
Saleh Mobayen ◽  
Leonardo Acho
Keyword(s):  
Pid Control ◽  
Magnetic Levitation ◽  
Low Cost ◽  
Control Scheme ◽  
Hands On ◽  
Levitation System ◽  
Magnetic Levitation System ◽  
And Control ◽  
Active Control Strategy ◽  
Cost Components

This paper describes how to construct a low-cost magnetic levitation system (MagLev). The MagLev has been intensively used in engineering education, allowing instructors and students to learn through hands-on experiences of essential concepts, such as electronics, electromagnetism, and control systems. Built from scratch, the MagLev depends only on simple, low-cost components readily available on the market. In addition to showing how to construct the MagLev, this paper presents a semi-active control strategy that seems novel when applied to the MagLev. Experiments performed in the laboratory provide comparisons of the proposed control scheme with the classical PID control. The corresponding real-time experiments illustrate both the effectiveness of the approach and the potential of the MagLev for education.

Modeling and Control of a Rotary Crane

1985 ◽  
Vol 107 (3) ◽  
pp. 200-206 ◽  
Author(s):  
Y. Sakawa ◽  
A. Nakazumi
Keyword(s):  
Feedback Control ◽  
Equilibrium State ◽  
Open Loop ◽  
The State ◽  
Control Input ◽  
Loop Control ◽  
Modeling And Control ◽  
Control Scheme ◽  
Rotary Crane ◽  
And Control

In this paper we first derive a dynamical model for the control of a rotary crane, which makes three kinds of motion (rotation, load hoisting, and boom hoisting) simultaneously. The goal is to transfer a load to a desired place in such a way that at the end of transfer the swing of the load decays as quickly as possible. We first apply an open-loop control input to the system such that the state of the system can be transferred to a neighborhood of the equilibrium state. Then we apply a feedback control signal so that the state of the system approaches the equilibrium state as quickly as possible. The results of computer simulation prove that the open-loop plus feedback control scheme works well.

Design and Analysis of a Multimodal Grasper Having Shape Conformity and Within-Hand Manipulation With Adjustable Contact Forces

2019 ◽  
Vol 11 (5) ◽  
Author(s):  
Nagamanikandan Govindan ◽  
Asokan Thondiyath
Keyword(s):  
Control Strategies ◽  
Low Cost ◽  
Active Surface ◽  
Force Sensor ◽  
Contact Forces ◽  
Geometrical Shape ◽  
Planning And Control ◽  
Control Scheme ◽  
And Control ◽  
Compact Mechanism

Abstract This paper presents the design, analysis, and testing of a novel multimodal grasper having the capabilities of shape conformation, within-hand manipulation, and a built-in compact mechanism to vary the forces at the contact surface. The proposed grasper has two important qualities: versatility and less complexity. The former refers to the ability to grasp a range of objects having different geometrical shape, size, and payload and perform in-hand manipulations such as rolling and sliding, and the latter refers to the uncomplicated design, and ease of planning and control strategies. Increasing the number of functions performed by the grasper to adapt to a variety of tasks in structured and unstructured environments without increasing the mechanical complexity is the main interest of this research. The proposed grasper consists of two hybrid jaws having a rigid inner structure encompassed by a flexible, active gripping surface. The flexibility of the active surface has been exploited to achieve shape conformation, and the same has been utilized with a compact mechanism, introduced in the jaws, to vary the contact forces while grasping and manipulating an object. Simple and scalable structure, compactness, low cost, and simple control scheme are the main features of the proposed design. Detailed kinematic and static analysis are presented to show the capability of the grasper to adjust and estimate the contact forces without using a force sensor. Experiments are conducted on the fabricated prototype to validate the different modes of operation and to evaluate the advantages of the proposed concept.

Modeling and control through leadership of a refined flocking system

2014 ◽  
Vol 25 (02) ◽  
pp. 255-282 ◽  
Author(s):  
Alfio Borzì ◽  
Suttida Wongkaew
Keyword(s):  
Predictive Control ◽  
Control Strategy ◽  
Social Systems ◽  
Open Loop ◽  
Modeling And Control ◽  
Control Scheme ◽  
Nonlinear Conjugate Gradient ◽  
Optimality Systems ◽  
And Control ◽  
Conjugate Gradient Solver

A new refined flocking model that includes self-propelling, friction, attraction and repulsion, and alignment features is presented. This model takes into account various behavioral phenomena observed in biological and social systems. In addition, the presence of a leader is included in the system in order to develop a control strategy for the flocking model to accomplish desired objectives. Specifically, a model predictive control scheme is proposed that requires the solution of a sequence of open-loop optimality systems. An accurate Runge–Kutta scheme to discretize the optimality systems and a nonlinear conjugate gradient solver are implemented and discussed. Numerical experiments are performed that investigate the properties of the refined flocking model and demonstrate the ability of the control strategy to drive the flocking system to attain a desired target configuration and to follow a given trajectory.

scholarly journals Nonlinear control of GTI for stabilizing future smart grids

2020 ◽  
Vol 11 (3) ◽  
pp. 1268
Author(s):  
Salam Ibrahim Khather
Keyword(s):  
Control Systems ◽  
Distributed Generation ◽  
Smart Grids ◽  
High Performance ◽  
Low Cost ◽  
Control Parameters ◽  
Leakage Currents ◽  
Control Techniques ◽  
Control Scheme ◽  
And Control

The most important components of the distributed generation frameworks is the GTIs which is an interface amidst the utility and the source of energy. The recent years have seen an increased interest in the design and usage of GTIs due to its smaller weight and size, low cost and higher efficiency. But the problem of leakage currents in the transformerless inverter that is dependant on its topology and control scheme needs to be looked into carefully. Also, the high performance of the GTI requires a stringent control and various control systems are being developed and applied to the GTIs. This paper reviews the various topologies that are classified based on the attributes of the leakage current and the method of decoupling. Further it reviews and compares the different control techniques applied to the GTIs with respect to the frame of reference, controller, modulation technique and the control parameters considered.

Progress of liquid crystal adaptive optics for applications in ground-based telescopes

2020 ◽  
Vol 494 (3) ◽  
pp. 3536-3540
Author(s):  
Xingyun Zhang ◽  
Zhaoliang Cao ◽  
Quanquan Mu ◽  
Dayu Li ◽  
Zenghui Peng ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Liquid Crystal ◽  
Adaptive Optics ◽  
Low Cost ◽  
Response Speed ◽  
Open Loop ◽  
Loop Control ◽  
Compact Size ◽  
Control Scheme ◽  
Resolution Imaging

ABSTRACT Liquid crystal (LC) adaptive optics systems (AOS) can potentially be used in ground-based large aperture telescopes, because of their high spatial resolution, low cost and compact size. However, their disadvantages, such as low energy efficiency and slow response speed, still hinder their application. In this paper, we demonstrate solutions to these problems. With newly synthesized fast nematic LC material and using an overdriving technique, the response time of a LC wavefront corrector was reduced to 0.75 ms. Under an open-loop control scheme, a novel optical system was designed to improve the energy efficiency of LC AOS. With those problems resolved, a LC AOS was built for a 1.23-m telescope. This system has a disturbance rejection bandwidth of 80 Hz, and could fully use the energy of 400–900 nm wavebands. Observation results showed that the diffraction limit resolution imaging of the telescope could be obtained after correction, which indicates that the LC AOS is ready to be used in ground-based telescopes for visible waveband imaging.

scholarly journals Quantum demolition filtering and optimal control of unstable systems

2012 ◽  
Vol 370 (1979) ◽  
pp. 5396-5407 ◽  
Author(s):  
V. P. Belavkin
Keyword(s):  
Optimal Control ◽  
Feedback Control ◽  
Open Loop ◽  
Information Dynamics ◽  
Unstable Systems ◽  
Dissipative Term ◽  
Control Scheme ◽  
Hamilton Jacobi Bellman ◽  
Classical Control ◽  
And Control

A brief account of the quantum information dynamics and dynamical programming methods for optimal control of quantum unstable systems is given to both open loop and feedback control schemes corresponding respectively to deterministic and stochastic semi-Markov dynamics of stable or unstable systems. For the quantum feedback control scheme, we exploit the separation theorem of filtering and control aspects as in the usual case of quantum stable systems with non-demolition observation. This allows us to start with the Belavkin quantum filtering equation generalized to demolition observations and derive the generalized Hamilton–Jacobi–Bellman equation using standard arguments of classical control theory. This is equivalent to a Hamilton–Jacobi equation with an extra linear dissipative term if the control is restricted to Hamiltonian terms in the filtering equation. An unstable controlled qubit is considered as an example throughout the development of the formalism. Finally, we discuss optimum observation strategies to obtain a pure quantum qubit state from a mixed one.

scholarly journals Soft Sensors for Biomass Monitoring during Low Cost Cellulase Production

2021 ◽  
Author(s):  
Chitra Murugan
Keyword(s):  
Fermentation Process ◽  
Control Strategies ◽  
Low Cost ◽  
Cellulase Production ◽  
Monitoring And Control ◽  
Soft Sensors ◽  
Control Scheme ◽  
Solid Substrates ◽  
Biomass Monitoring ◽  
And Control

Low cost cellulase production has become a major challenge in recent years. The major hurdle in the production of biofuel and other products from biomass is the lack of efficient economically feasible cellulase. This can be achieved by proper monitoring and control of bioprocess. In order to implement any control scheme, the accurate representation of the system in the form of a model is necessary. There are many challenges associated with modeling the fermentation process such as inherent nonlinear dynamic behavior, complexity of process due to co-existence of viable and nonviable cells, presence of solid substrates, etc. Toward the achievement of this goal, researchers have been developing new techniques that can be used to monitor the process online and at-line. These newer techniques have paved the way for designing better control strategies that can be integrated with quality by design (QbD) and process analytic technology (PAT).

scholarly journals Experimental maneuverability and agility quantification for rotary unmanned aerial vehicle

2017 ◽  
Vol 10 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Jon Verbeke ◽  
Joris De Schutter
Keyword(s):  
Low Cost ◽  
Test Procedure ◽  
Open Loop ◽  
Unmanned Aircraft ◽  
Test Procedures ◽  
Minimum Requirements ◽  
Aerial Vehicle ◽  
And Control ◽  
Published Research ◽  
Rotary Type

Multicopters are the most popular rotary type of unmanned aerial vehicles. They are a type of helicopter with three or more, usually fixed-pitch, propellers that lift and control the platform by individually changing their rotational velocities. The main advantages of a multicopter are its compactness, robustness, and low cost to build and repair. However, currently no published research determines objectively, quantitatively, and experimentally, the maneuverability and agility of multicopters. Numerous maneuverability and agility metrics, together with detailed test procedures and minimum requirements, exist for manned aircraft. Nevertheless, some of these are not directly applicable to small-size unmanned aircraft. A new test procedure, derived from manned aircraft industry practices and research, based on a simple open-loop step input maneuver, was developed. It experimentally determines nine maneuverability and agility metrics using only onboard flight controller logs. The test procedure is validated using two different multicopters.

Contactless transmission of power and control signals by multiplexing the frequency

2018 ◽  
Author(s):  
Nikolay Madzharov ◽  
Lyudmil Petkov ◽  
Panagiotis Kogias ◽  
Konstantinos Karakoulidis
Keyword(s):  
Control Signals ◽  
Power And Control ◽  
And Control
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