scholarly journals Decentralized Motion Control for Omnidirectional Wheelchair Tracking Error Elimination Using PD-Fuzzy-P and GA-PID Controllers

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3525
Author(s):  
Wafa Batayneh ◽  
Yusra AbuRmaileh
Keyword(s):  
Research Effort ◽  
Tracking Error ◽  
Vertical Motion ◽  
The Body ◽  
Automated Guided Vehicles ◽  
Pid Controllers ◽  
Body Frame ◽  
Wheelchair Users ◽  
Smart Wheelchairs ◽  
Significant Research

The last decade observed a significant research effort directed towards maneuverability and safety of mobile robots such as smart wheelchairs. The conventional electric wheelchair can be equipped with motorized omnidirectional wheels and several sensors serving as inputs for the controller to achieve smooth, safe, and reliable maneuverability. This work uses the decentralized algorithm to control the motion of omnidirectional wheelchairs. In the body frame of the omnidirectional wheeled wheelchair there are three separated independent components of motion including rotational motion, horizontal motion, and vertical motion, which can be controlled separately. So, each component can have its different sub-controller with a minimum tracking error. The present work aims to enhance the mobility of wheelchair users by utilizing an application to control the motion of their attained/unattained smart wheelchairs, especially in narrow places and at hard detours such as 90˚ corners and U-turns, which improves the quality of life of disabled users by facilitating their wheelchairs’ maneuverability. Two approaches of artificial intelligent-based controllers (PD-Fuzzy-P and GA-PID controllers) are designed to optimally enhance the maneuverability of the system. MATLAB software is used to simulate the system and calculate the Mean Error (ME) and Mean Square Error (MSE) for various scenarios in both approaches, the results showed that the PD-Fuzzy-P controller has a faster convergence in trajectory tracking than the GA-PID controller. Therefore, the proposed system can find its application in many areas including transporting locomotor-based disabled individuals and geriatric people as well as automated guided vehicles.

Novel three-dimensional optimal path planning method for vehicles with constrained pitch and yaw

Robotica ◽  
2016 ◽  
Vol 35 (11) ◽  
pp. 2157-2176 ◽  
Author(s):  
B. Wehbe ◽  
S. Bazzi ◽  
E. Shammas
Keyword(s):  
Path Planning ◽  
Optimal Path ◽  
Three Dimensional ◽  
Vertical Motion ◽  
The Body ◽  
Planning Method ◽  
Optimal Trajectories ◽  
Planning Problem ◽  
Body Frame ◽  
Time Optimal

SUMMARYThis paper presents a novel method for generating three-dimensional optimal trajectories for a vehicle or body that moves forward at a constant speed and steers in both horizontal and vertical directions. The vehicle's dynamics limit the body-frame pitch and yaw rates; additionally, the climb and decent angles of the vehicle are also bounded. Given the above constraints, the path planning problem is solved geometrically by building upon the two-dimensional Dubins curves and then Pontryagin's Maximum Principle is used to validate that the proposed solution lies within the family of candidate time-optimal trajectories. Finally, given the severe boundedness constraints on the vertical motion of the system, the robustness of the proposed path planning method is validated by naturally extending it to remain applicable to high-altitude final configurations.

Implementations of PID Controller and its Transient Behaviour in Active Suspension System

2014 ◽  
Vol 895 ◽  
pp. 490-499 ◽  
Author(s):  
Noor Hafizah Amer ◽  
Rahizar Ramli ◽  
Wan Nor Liza Wan Mahadi ◽  
Mohd Azman Zainul Abidin ◽  
Zainab Rasol
Keyword(s):  
Pid Controller ◽  
Ride Comfort ◽  
Research Effort ◽  
Active Suspension ◽  
Suspension System ◽  
The Body ◽  
Pid Controllers ◽  
Active Force ◽  
Transient Behaviour ◽  
Vehicle Suspension System

Advancement in computational technologies has accelerated the research effort in exploring the possibility of semi-active and active suspension. Computational simulations were used widely in the studies of the controller strategies. Among them are PID controllers. Studies from previous work suggested that PID controllers are capable of improving ride comfort and road holding capability. However, very little emphasis is given to examine the whole state of the vehicle suspension system resulted from this implementation. Therefore this study will examine the application of a basic PID controller to an active suspension system (ASS) to determine the requirement of active force that should be delivered in stabilizing the whole system. Two different configurations of electromagnetic suspension system (EMS) will be considered. One variable in the vehicle system will be selected to be the controlled output of PID controller and its effect to overall vehicle state will be observed. In the cases that the PID was able to stabilize the body responses, deterioration was noticed in the wheel responses. While it stabilizes the controlled output, the active force from controller was channelled into deteriorating other vehicle parameters.

scholarly journals Dynamic Modeling and Simulation of a Body Weight Support System

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Zhendong Song ◽  
Wei Chen ◽  
Wenbing Wang ◽  
Guoqing Zhang
Keyword(s):  
Body Weight ◽  
Control Process ◽  
Vertical Motion ◽  
The Body ◽  
Body Weight Support ◽  
Gait Rehabilitation ◽  
Series Elastic Actuator ◽  
Weight Support ◽  
Support Force ◽  
Body Weight Support System

This paper proposes a body weight support (BWS) system with a series elastic actuator (SEA) to facilitate walking assistance and motor relearning during gait rehabilitation. This system comprises the following: a mobile platform that ensures movement of the system on the ground, a BWS mechanism with an SEA that is capable of providing the desired unloading force, and a pelvic brace to smooth the pelvis motions. The control of the body weight support is realized by an active weight-offload method, and a dynamic model of the BWS system with offload mass of a human is conducted to simulate the control process and optimize the parameters. Preliminary results demonstrate that the BWS system can provide the desired support force and vertical motion of the pelvis.

Dynamic modeling and design of controller for the 2-DoF serial chain actuated by a cable-driven robot based on feedback linearization

2021 ◽  
pp. 095440622110279
Author(s):  
Vahid Bahrami ◽  
Ahmad Kalhor ◽  
Mehdi Tale Masouleh
Keyword(s):  
Dynamic Modeling ◽  
Pid Controller ◽  
Feedback Linearization ◽  
Tracking Error ◽  
Pid Controllers ◽  
Serial Chain ◽  
Simulation Results ◽  
The Stability ◽  
Feedback Linearization Approach ◽  
Bounded Disturbance

This study intends to investigate a dynamic modeling and design of controller for a planar serial chain, performing 2-DoF, in interaction with a cable-driven robot. The under study system can be used as a rehabilitation setup which is helpful for those with arm disability. The latter goal can be achieved by applying the positive tensions of the cable-driven robot which are designed based on feedback linearization approach. To this end, the system dynamics formulation is developed using Lagrange approach and then the so-called Wrench-Closure Workspace (WCW) analysis is performed. Moreover, in the feedback linearization approach, the PD and PID controllers are used as auxiliary controllers input and the stability of the system is guaranteed as a whole. From the simulation results it follows that, in the presence of bounded disturbance based on Roots Mean Square Error (RMSE) criteria, the PID controller has better performance and tracking error of the 2-DoF robot joints are improved 15.29% and 24.32%, respectively.

scholarly journals Systematic review of evidence underpinning non-pharmacological therapies in dementia

2018 ◽  
Vol 42 (4) ◽  
pp. 361 ◽  
Author(s):  
Richard Olley ◽  
Andrea Morales
Keyword(s):  
Systematic Review ◽  
Sleep Disturbances ◽  
Research Effort ◽  
Evidence Base ◽  
Pharmacological Therapy ◽  
Sufficient Evidence ◽  
Behavioural Treatment ◽  
Significant Research ◽  
Research Gap ◽  
Meta Analyses

Objective Dementia is one of the most common illnesses worldwide, and is one of the most important causes of disability in older people. Currently, dementia affects over 35 million people around the globe. It is expected that this number will increase to 65.7 million by 2030. Early detection, diagnosis and treatment to control the principal behaviour symptoms may help reduce these numbers and delay the progression to more advanced and dangerous stages of this disorder with resultant increase quality of life for those affected. The main goal of the present systematic literature review was to examine contemporary evidence relating to non-pharmacological therapy in the treatment of dementia. Methods To achieve the study goal, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was used. Results This study identified the five most common behaviours in patients with dementia as aggression, wandering, agitation, apathy and sleep disturbances. Two non-pharmacological therapies were the most studied treatment: music therapy and aromatherapy. Ten other non-pharmacological therapies were also identified, but these lack a sufficient evidence-base. Conclusion Although all the therapies identified could be used as part of the treatment of behavioural symptoms, there is insufficient evidence relating to the indications, appropriate use and effectiveness of these therapies to apply in each behavioural treatment. Thus, the present study has demonstrated a significant research gap. What is known about the topic? Despite the widespread use of many different types of therapies, there is limited evidence regarding the efficacy of non-pharmaceutical therapies deployed in the management of behaviours of concern manifested by some people who suffer with dementia in all its forms. What does this paper add? This systematic review examines contemporary evidence from the literature to determine whether there is an evidence base available that would underpin the use of these therapies. This report on a PRISMA systematic review of the available literature demonstrates that only two therapies have some evidence to underpin the use of these non-pharmaceutical therapies and that a significant research gap is exists. What are the implications for practitioners? The implications for practitioners is that significant research effort is required to determine the efficacy of many of the therapies that are currently deployed, and thus many of the therapies used lack an evidence base at this time.

Electric Bus Body Lightweight Design Based on Multiple Constrains

2012 ◽  
Vol 538-541 ◽  
pp. 3137-3144 ◽  
Author(s):  
Wen Wei Wang ◽  
Cheng Jun Zhou ◽  
Cheng Lin ◽  
Jiao Yang Chen
Keyword(s):  
Finite Element ◽  
Lightweight Design ◽  
Element Model ◽  
The Body ◽  
Body Frame ◽  
Electric Bus ◽  
Free Model ◽  
Bus Body ◽  
The Finite Element Model ◽  
Torsion Condition

The finite-element model of pure electric bus has been built and the free model analysis, displacement and stress analysis under bending condition and torsion condition have been conducted. Optimally design the pure electric bus frame based on multiple constrains. Reduce the body frame quality by 4.3% and meanwhile meet the modal and stress requirements.

Interlaced Attitude Estimation for Spacecraft Using Vector Observations

2021 ◽  
Vol 01 (03) ◽  
Author(s):  
Lubin Chang
Keyword(s):  
Prior Information ◽  
State Of The Art ◽  
Estimation Method ◽  
Attitude Estimation ◽  
The Body ◽  
Body Frame ◽  
Initial Value ◽  
Initial State ◽  
Initial Errors ◽  
Initial Attitude

This paper proposes an interlaced attitude estimation method for spacecraft using vector observations, which can simultaneously estimate the constant attitude at the very start and the attitude of the body frame relative to its initial state. The arbitrary initial attitude, described by constant attitude at the very start, is determined using quaternion estimator which requires no prior information. The multiplicative extended Kalman filter (EKF) is competent for estimating the attitude of the body frame relative to its initial state since the initial value of this attitude is exactly known. The simulation results show that the proposed algorithms could achieve better performance compared with the state-of-the-art algorithms even with extreme large initial errors. Meanwhile, the computational burden is also much less than that of the advanced nonlinear attitude estimators.

Software Metrics and Design Quality in Object Oriented Paradigm

2011 ◽  
pp. 256-272
Author(s):  
Gopalakrishnan T.R. Nair ◽  
Selvarani R
Keyword(s):  
Risk Assessment ◽  
Software Metrics ◽  
Research Effort ◽  
Object Oriented ◽  
Object Oriented Programming ◽  
Quality Factors ◽  
Engineering Software ◽  
Building Models ◽  
Future Challenges ◽  
Significant Research

As the object oriented programming languages and development methodologies moved forward, a significant research effort was spent in defining specific approaches and building models for quality based on object oriented measurements. Software metrics research and practice have helped in building an empirical basis for software engineering. Software developers require objectives and valid measurement schemes for the evaluation and improvisation of product quality from the initial stages of development. Measuring the structural design properties of a software system such as coupling, inheritance, cohesion, and complexity is a promising approach which can lead to an early quality assessment. The class codes and class diagrams are the key artifacts in the development of object oriented (OO) software and it constitutes the backbone of OO development. It also provides a solid foundation for the design and development of software with a greater influence over the system that is implemented. This chapter presents a survey of existing relevant works on class code / class diagram metrics in an elaborate way. Here, a critical review of the existing work is carried out in order to identify the lessons learnt regarding the way these studies are performed and reported. This work facilitates the development of an empirical body of knowledge. The classical approaches based on statistics alone do not provide managers and developers with a decision support scheme for risk assessment and cost reduction. One of the future challenges is to use software metrics in a way that they creatively address and handle the key objectives of risk assessment and the estimation of external quality factors of the software.

scholarly journals Psychosomatic Approach to Fibromyalgia Syndrome: Medical, Psychological, and Social Aspects

2020 ◽  
Author(s):  
José Vicente Martínez-Quiñones ◽  
Mar Martínez Gamarra ◽  
Ignacio Jáuregui-Lobera
Keyword(s):  
Pain Perception ◽  
Medical Profession ◽  
The Body ◽  
Pain Pathways ◽  
Central Sensitivity Syndrome ◽  
Significant Research ◽  
Research Findings ◽  
Rheumatic Conditions ◽  
Central Pain Processing

Management of patients who describe chronic pain all over the body, associated with a range of symptoms as sleep disturbance, overwhelming fatigue, alteration in mood, or psychological distress that worsens the quality of life, is often complex and challenging. This syndrome has been named by terms such as “neurasthenia,” “fibrositis,” and “fibromyalgia”. At the present time, fibromyalgia is considered the most common central sensitivity syndrome, affecting over 5% of the population, being often observed in people with rheumatic conditions. While typically presenting in middle-aged women, fibromyalgia can affect both sexes at any age. The causes of fibromyalgia remain unknown. Significant research findings have focused on dysfunction of central pain processing, with defects in the ascending and descending pain pathways leading to increased pain perception. There are two methods used in the diagnosis of fibromyalgia: criteria-based diagnosis and clinical diagnosis. Although fibromyalgia defies definitively efficacious management, much evidence underlies the importance of treating the psychological factors that affect pain management process. The primary purpose of this paper is to provide a psychosomatic approach to fibromyalgia from three points of view of processing: the viewpoint of the medical profession, the position of the psychologist, and finally the way of thinking of people.

scholarly journals A Novel Framework for Road Traffic Risk Assessment with HMM-Based Prediction Model

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4313 ◽  
Author(s):  
Xunjia Zheng ◽  
Di Zhang ◽  
Hongbo Gao ◽  
Zhiguo Zhao ◽  
Heye Huang ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Road Traffic ◽  
Research Effort ◽  
Assessment Method ◽  
Intelligent Vehicles ◽  
Steering Angle ◽  
The Road ◽  
Risk Assessment Method ◽  
Significant Research ◽  
Assessment Strategies

Over the past decades, there has been significant research effort dedicated to the development of intelligent vehicles and V2X systems. This paper proposes a road traffic risk assessment method for road traffic accident prevention of intelligent vehicles. This method is based on HMM (Hidden Markov Model) and is applied to the prediction of steering angle status to (1) evaluate the probabilities of the steering angle in each independent interval and (2) calculate the road traffic risk in different analysis regions. According to the model, the road traffic risk is quantified and presented directly in a visual form by the time-varying risk map, to ensure the accuracy of assessment and prediction. Experiment results are presented, and the results show the effectiveness of the assessment strategies.

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