scholarly journals Patient-Centered Robot-Aided Passive Neurorehabilitation Exercise Based on Safety-Motion Decision-Making Mechanism

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Lizheng Pan ◽  
Aiguo Song ◽  
Suolin Duan ◽  
Zhuqing Yu
Keyword(s):  
Decision Making ◽  
Control Strategy ◽  
Position Control ◽  
Impedance Control ◽  
Control Strategies ◽  
Movement Speed ◽  
Stroke Patients ◽  
Patient Centered ◽  
Motion Speed ◽  
Clinical Experiments

Safety is one of the crucial issues for robot-aided neurorehabilitation exercise. When it comes to the passive rehabilitation training for stroke patients, the existing control strategies are usually just based on position control to carry out the training, and the patient is out of the controller. However, to some extent, the patient should be taken as a “cooperator” of the training activity, and the movement speed and range of the training movement should be dynamically regulated according to the internal or external state of the subject, just as what the therapist does in clinical therapy. This research presents a novel motion control strategy for patient-centered robot-aided passive neurorehabilitation exercise from the point of the safety. The safety-motion decision-making mechanism is developed to online observe and assess the physical state of training impaired-limb and motion performances and regulate the training parameters (motion speed and training rage), ensuring the safety of the supplied rehabilitation exercise. Meanwhile, position-based impedance control is employed to realize the trajectory tracking motion with interactive compliance. Functional experiments and clinical experiments are investigated with a healthy adult and four recruited stroke patients, respectively. The two types of experimental results demonstrate that the suggested control strategy not only serves with safety-motion training but also presents rehabilitation efficacy.

A Robust Approach to Dynamic Feedback Linearization for a Steerable Nips Mechanism

2008 ◽  
Author(s):  
Edgar I. Ergueta ◽  
Robert Seifried ◽  
Roberto Horowitz
Keyword(s):  
Control Strategy ◽  
Feedback Linearization ◽  
Position Control ◽  
Control Strategies ◽  
Successful Implementation ◽  
Experimental Setup ◽  
Dynamic Feedback ◽  
Robust Approach ◽  
Internal Loops ◽  
Steerable Nips

This paper presents two different control strategies for paper position control in printing devices. The first strategy is based on feedback linearization plus dynamic extension (dynamic feed-back linearization). Even though this controller is very simple to design, we show that it is not able to handle actuator multiplicative uncertainties, and therefore it fails when it is implemented on the experimental setup. The second strategy we present uses similar concepts, but it is more robust since feedback linearization is used only to linearize the kinematics of the system and internal loops are used to locally control the actuator’s positions and velocities. Not only do we prove the robustness of the second control strategy, but we also show its successful implementation.

Position control and performance analysis of hydraulic system using two pump-controlling strategies

2018 ◽  
Vol 233 (9) ◽  
pp. 1093-1105 ◽  
Author(s):  
Gyan Wrat ◽  
Prabhat Ranjan ◽  
Mohit Bhola ◽  
Santosh Kumar Mishra ◽  
J Das
Keyword(s):  
Control Strategy ◽  
Position Control ◽  
Control Strategies ◽  
Speed Control ◽  
Hydraulic Systems ◽  
Proportional Integral Derivative ◽  
Proportional Integral Derivative Controller ◽  
Proportional Integral ◽  
Actuation System ◽  
Swash Plate

The role of hydraulic systems is quite evident especially in the case of heavy machineries employed in industries, where the utilisation of high forces amid large stiffness is the prerequisite. Nevertheless, there has been substantial effort put forward in the development of advanced control strategies which finally addressed the issue of the position control. Proportional–integral–derivative control strategy happens to be one among them, which is a versatile and widely renowned approach involved in the position control in this study. Although, it is quite frequently observed that the hydraulic actuation system possesses strong nonlinearities. In this article, two different actuator position control strategies, that is, swash plate control of main pump and speed control strategy of prime mover are compared. In swash plate control strategy, the proportional–integral–derivative controller adjusts the swash plate of main pump through servo mechanism, whereas in the speed control strategy, the proportional–integral–derivative controller adjusts the speed of the electric motor through variable-frequency drive. For this purpose, two MATLAB-Simulink models are developed and validated experimentally. It is found that swash plate control strategy has better dynamic and control performance than the speed control strategy catering same position demand of the linear actuator.

scholarly journals Control strategies for cleaning robots in domestic applications: A comprehensive review

2019 ◽  
Vol 16 (4) ◽  
pp. 172988141985743 ◽  
Author(s):  
Jaeseok Kim ◽  
Anand Kumar Mishra ◽  
Raffaele Limosani ◽  
Marco Scafuro ◽  
Nino Cauli ◽  
...  
Keyword(s):  
Elderly People ◽  
Position Control ◽  
Impedance Control ◽  
Control Strategies ◽  
Service Robots ◽  
Control Force ◽  
Control Methods ◽  
Data Set ◽  
Increasing Demand ◽  
Classical Control

Service robots are built and developed for various applications to support humans as companion, caretaker, or domestic support. As the number of elderly people grows, service robots will be in increasing demand. Particularly, one of the main tasks performed by elderly people, and others, is the complex task of cleaning. Therefore, cleaning tasks, such as sweeping floors, washing dishes, and wiping windows, have been developed for the domestic environment using service robots or robot manipulators with several control approaches. This article is primarily focused on control methodology used for cleaning tasks. Specifically, this work mainly discusses classical control and learning-based controlled methods. The classical control approaches, which consist of position control, force control, and impedance control , are commonly used for cleaning purposes in a highly controlled environment. However, classical control methods cannot be generalized for cluttered environment so that learning-based control methods could be an alternative solution. Learning-based control methods for cleaning tasks can encompass three approaches: learning from demonstration (LfD), supervised learning (SL), and reinforcement learning (RL). These control approaches have their own capabilities to generalize the cleaning tasks in the new environment. For example, LfD, which many research groups have used for cleaning tasks, can generate complex cleaning trajectories based on human demonstration. Also, SL can support the prediction of dirt areas and cleaning motion using large number of data set. Finally, RL can learn cleaning actions and interact with the new environment by the robot itself. In this context, this article aims to provide a general overview of robotic cleaning tasks based on different types of control methods using manipulator. It also suggest a description of the future directions of cleaning tasks based on the evaluation of the control approaches.

Finite-Time Settling Control of a Flexible Arm

1994 ◽  
Vol 208 (2) ◽  
pp. 79-87 ◽  
Author(s):  
S Choura
Keyword(s):  
Control Strategy ◽  
Finite Time ◽  
Position Control ◽  
Feedforward Control ◽  
Control Strategies ◽  
State Space Model ◽  
Control Law ◽  
Flexible Beam ◽  
Flexible Arm ◽  
Finite Set

This paper considers the position control of a flexible beam attached to a rotating rigid hub. The control torque is applied at the hub through a motor. A state-space model describing the motion of the flexible beam is developed and is employed in the design of the control law. The finite-time settling control strategy that combines feedback and feedforward is applied to the beam problem. The feedback part is separately designed to resolve the issues of asymptotic stability and robustness to uncertainties. The feedforward part simultaneously suppresses the rigid-body mode and a finite set of flexible modes at the end of manoeuvre and, therefore, it is the part responsible for the finite-time settling of the beam to its final configuration. It is shown that if the finite-time settling control is compared with previously developed control strategies under the same input bound constraint, it leads to a better suppression of vibrations at the end of manoeuvre, provided that a sufficient number of flexible modes are incorporated in the computation of the feedforward control law. A robustness test is carried out to show the viability of the control strategy supported by computer simulations.

A Robust Approach to Dynamic Feedback Linearization for a Steerable Nips Mechanism

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Edgar I. Ergueta ◽  
Robert Seifried ◽  
Roberto Horowitz
Keyword(s):  
Control Strategy ◽  
Feedback Linearization ◽  
Position Control ◽  
Control Strategies ◽  
Successful Implementation ◽  
Experimental Setup ◽  
Dynamic Feedback ◽  
Robust Approach ◽  
Internal Loops ◽  
Steerable Nips

This paper presents two different control strategies for paper position control in printing devices. The first strategy is based on standard feedback linearization plus dynamic extension (dynamic feedback linearization). Even though this controller is very simple to design, we show that it is not able to handle actuator multiplicative uncertainties, and therefore, it fails when it is implemented on the experimental setup. The second strategy we present uses similar concepts, but it is more robust since feedback linearization is used only to linearize the kinematics of the system and internal loops are used to locally control the actuator’s positions and velocities. In this paper, not only do we formally prove the robustness of the second control strategy but we also show its successful implementation.

scholarly journals Towards Adjustable Autonomy for the Real World

2002 ◽  
Vol 17 ◽  
pp. 171-228 ◽  
Author(s):  
P. Scerri ◽  
D. V. Pynadath ◽  
M. Tambe
Keyword(s):  
Decision Making ◽  
Real World ◽  
Control Strategy ◽  
Control Strategies ◽  
Research Problem ◽  
Individual Agent ◽  
Team Members ◽  
Adjustable Autonomy ◽  
Novel Approach ◽  
Individual Decisions

Adjustable autonomy refers to entities dynamically varying their own autonomy, transferring decision-making control to other entities (typically agents transferring control to human users) in key situations. Determining whether and when such transfers-of-control should occur is arguably the fundamental research problem in adjustable autonomy. Previous work has investigated various approaches to addressing this problem but has often focused on individual agent-human interactions. Unfortunately, domains requiring collaboration between teams of agents and humans reveal two key shortcomings of these previous approaches. First, these approaches use rigid one-shot transfers of control that can result in unacceptable coordination failures in multiagent settings. Second, they ignore costs (e.g., in terms of time delays or effects on actions) to an agent's team due to such transfers-of-control. To remedy these problems, this article presents a novel approach to adjustable autonomy, based on the notion of a transfer-of-control strategy. A transfer-of-control strategy consists of a conditional sequence of two types of actions: (i) actions to transfer decision-making control (e.g., from an agent to a user or vice versa) and (ii) actions to change an agent's pre-specified coordination constraints with team members, aimed at minimizing miscoordination costs. The goal is for high-quality individual decisions to be made with minimal disruption to the coordination of the team. We present a mathematical model of transfer-of-control strategies. The model guides and informs the operationalization of the strategies using Markov Decision Processes, which select an optimal strategy, given an uncertain environment and costs to the individuals and teams. The approach has been carefully evaluated, including via its use in a real-world, deployed multi-agent system that assists a research group in its daily activities.

Coordinated speed and position control of integrated motor-transmission system

2021 ◽  
pp. 014233122110151
Author(s):  
Wei Li ◽  
Chen Kang ◽  
Xiaoyuan Zhu
Keyword(s):  
Control Strategy ◽  
Position Control ◽  
Control Strategies ◽  
Axial Position ◽  
Position Tracking ◽  
Motor Speed ◽  
Displacement Control ◽  
Time Value ◽  
Dynamical Characteristics ◽  
Speed Change

In this paper, a coordinated driving motor speed and shifting motor displacement control strategy is proposed for the integrated motor-transmission (IMT) system during the gearshift process. For active speed synchronization of IMT system, speed reference to driving motor is redesigned by using a polynomial speed trajectory. Compared with conventional step speed change reference, it can help improve the ride performance of IMT system. While in the gear release as well as engagement phase, a robust optimal preview controller is developed for the shifting motor to realize rapid and reliable position tracking of the sleeve in spite of load disturbance. Based on real time value of the driving motor speed and also sleeve axial position, proposed speed and position controllers are coordinated in plan during the whole gearshift process. Co-simulations with Matlab/Simulink and AMEsim are conducted to demonstrate dynamical characteristics of the IMT system during the whole gear shifting process, in which a two-layer switching logic is built by using Matlab/Stateflow. Comparative simulation tests are carried out to show the effectiveness as well as performance of proposed control strategies.

scholarly journals Evaluation of an acceleration-based assistive strategy to control a back-support exoskeleton for manual material handling

2020 ◽  
Vol 1 ◽  
Author(s):  
Maria Lazzaroni ◽  
Ali Tabasi ◽  
Stefano Toxiri ◽  
Darwin G. Caldwell ◽  
Elena De Momi ◽  
...  
Keyword(s):  
Control Strategy ◽  
Material Handling ◽  
Muscle Activation ◽  
Control Strategies ◽  
Angular Acceleration ◽  
Movement Speed ◽  
Compression Force ◽  
Back Muscle ◽  
Manual Material Handling ◽  
New Strategy

Abstract To reduce the incidence of occupational musculoskeletal disorders, back-support exoskeletons are being introduced to assist manual material handling activities. Using a device of this type, this study investigates the effects of a new control strategy that uses the angular acceleration of the user’s trunk to assist during lifting tasks. To validate this new strategy, its effectiveness was experimentally evaluated relative to the condition without the exoskeleton as well as against existing strategies for comparison. Using the exoskeleton during lifting tasks reduced the peak compression force on the L5S1 disc by up to 16%, with all the control strategies. Substantial differences between the control strategies in the reductions of compression force, lumbar moment and back muscle activation were not observed. However, the new control strategy reduced the movement speed less with respect to the existing strategies. Thanks to improved timing in the assistance in relation to the typical dynamics of the target task, the hindrance to typical movements appeared reduced, thereby promoting intuitiveness and comfort.

Sign in / Sign up

Export Citation Format

Share Document