Forward and backward motion control of wheelchair on two wheels

The challenge in designing wheelchair on two wheels involves the design and implementation of suitable control strategies for a two wheeled wheelchair to perform comparably similar to a normal four wheeled wheelchair. It is important to note that a wheelchair on two wheels is expected not to take much space during mobility as compared to when it is on four wheels. Moreover, disabled people are encouraged and expected to perform most activities that others can do and hence lead an independent life. Thus, wheelchairs on two wheels are needed for disabled persons to perform some of the essential tasks in their living and work environments. In this research a model of the standard wheelchair is developed as a test and verification platform using Visual Nastran software. Novel fuzzy logic control strategies are designed for lifting up the chair transforming a four-wheeled wheelchair to a two-wheeled wheelchair) and maintaining stability and balance while on two wheels. Furthermore, position control for forward and backward mobility of the wheelchair on two wheels is developed using fuzzy logic control. Simulation results of the proposed control strategy are presented and discussed

Modelling and control of a wheelchair on two wheels

Wheelchairs on two wheels are needed for disabled persons to perform some of the essential tasks in their living and work environments. In fact it offers great advantages and efficiency for the user. Besides allowing a disabled to lead independent life, it is expected not to take much space during mobility as compared to when it is on four wheels and thus a wheelchair on two wheels has associated design and development challenges. These include modelling and controller design for the system to perform comparably similar to normal four-wheeled wheelchair. In this paper physical model of a wheelchair on two wheels that mimics double inverted pendulum is designed and a novel fuzzy logic control mechanism is developed and tested with control of the two-wheeled wheelchair

Implementation of fuzzy logic controller for wheelchair motion control based on EOG data

The study of this paper is to implementation the fuzzy logic control designed for wheelchair motion based on the eye movement signals using electrooculograhphy (EOG) technique. This technique is to acquire the eye movement data from a person, for example, tetraplegia. The tetraplegia is paralysis caused by illness or injury to a human that result in the partial or total loss of use of all their limbs and torso. The eye movement data which was obtained can be used as a main communication tool between human and machine. The PD-type fuzzy controller was successfully designed and tested on the wheelchair model, for control the linear motion (focused for forward motion). The wheelchair model was developed using MSC.Visual Nastran 4D. The results obtained show that the PD-type fuzzy logic controller designed has successfully managed to track the input reference for linear motion set by the EOG signal

Analysis of different level of EOG signal from eye movement for wheelchair control

This paper is aimed to analyze different levels of eye movement signals strength using Electrooculography (EOG). The eye movement that is known to be a significant communication tool for a tetraplegia, can be defined as a paralysis that is caused by serious injuries or illness to a human that lead to a partial or total loss of their lower limb and torso. A person who has such paralysis is highly dependent on an assistant and a wheelchair for movement. It is not always the case where the helper is with the patient all the time, therefore independence is encouraged among the wheelchair users. The signal from the eye muscles that is called electrooculogram is generated at different eye movements’ directions and levels. The eye movement signals are acquired using g.USBamp from G.TEC Medical Engineering GMBH by using Ag/AgCl electrodes. The data is then passed to MATLAB/SIMULINK software for data analysis. Different directions and strength level of eye movement are fed to a virtual wheelchair model developed in MSC.Visual Nastran 4D software to study the effect of the signals on the distance and rotation travelled by the wheelchair. Simulation exercises has verified that different strength of eye movement signals levels that have been processed could be manipulated for helping tetraplegia in their mobility using the wheelchair

The Attributes of Electronic Service Quality (e-SQ) among Academic Librarians

AbstractThis paper examines the level of electronic service quality (e-SQ) attributes among academic librarians in the Malaysian public universities which have an established automated library system. Six attributes of the e-SQ were determined from the analysis of related e-SQ theories. The 162 academic librarians respondents involved in this study were from nine public universities in West Malaysia. The findings of the research indicate that all the attributes have high level of mean, of which the two highest attribute are Reliability and Security. Thus, the research shows that the academic librarians of the Malaysian public universities are aware of the importance of e-SQ in their job since the overall attributes at the high level

Rejection of yaw disturbance in a two-wheeled wheelchair system

In this paper, a virtual wheelchair (WC) model is developed within Visual Nastran (VN) software environment where the model is further linked with Matlab/Simulink for control purposes. The goal is to have stable two-wheeled WC by transforming the two front wheels (caster) to the upright position. Theoretically, when the two big wheels are fed by the same torque, the WC system will only move in one (x-) direction (with a small forward and backward movement before settlement is achieved). On the other hand, WC in VN produces action-reaction forces in terms of friction between the wheels and the defined ground that lead to small degree of rotation with respect to vertical z- axis, (yaw disturbance). Fuzzy logic control is designed in order to eliminate this unwanted rotation of the wheels during lifting and stabilizing phase. Results show that the unwanted rotation of the wheels is successfully reduced

Fuzzy logic based temperature control of thermoelectric cooler (TEC) for single photon avalanche diode (SPAD) application

Single photon avalanche diode (SPAD) is a temperature sensitive device. Even a slight variation of temperature can cause unstable performance in quantum efficiency, responsitivity and dark counts. Due to these reasons,unstable temperature could cause overall poor performance of SPAD. It is common for thermoelectric cooler (TEC) to be used as cooling of photodetectors. SPAD was mounted onto the TEC where it needs to be maintained at a constant low temperature under variation of ambient temperature. The system is simulated using Fuzzy Logic Toolbox in MATLAB Simulink. Simulated using P-type fuzzy logic with the set point temperature of 20˚C and ambient temperature of 16˚C, produce a result of -19.44˚C. The P-type fuzzy logic control design has shown a good overall performance where the steady state error is ±0.56˚C, which is equivalent to ±2.8% and the settling time for the output simulation, ts, is 35.91s

Association between self-esteem and smoking among religous school students in Petaling District, Selangor

Introduction: According to the Youth Behaviour Risk Factor Surveillance (YBRFSS, 2011) in Malaysia, the prevalence of smokers nationally among Form 1, 2 and 4 students government secondary school students was 9.1% (ever smokers) and 8.7% (current smokers). However, there is limited information on the prevalence of smoking among religious secondary school students and self-esteem as risk factor. Thus, this study was conducted to determine the prevalence and factors associated with smoking among the religious secondary school students in Petaling district, Selangor. Methods: A cross-sectional study was conducted among 899 students. The schools were selected using cluster sampling and self-administered questionnaire was used. Data was analyzed using chi-square test and multivariate logistic regression to identify the independent factors for smoking. Results: The response rate was 94%. The prevalence of ever smoking was 10.1%; 3.9% among female and 18.6% among male. The median age (interquartile range) of smoking initiation was 12.00 (4.01) years. The results showed that independent factors for smoking were: males (OR= 5.47); age group 14-15years (OR=2.82) and 16-17 years (OR=3.63) and having low self -esteem (OR=6.24). Conclusion: prevalence of ever smokers is higher when compared to YBRFSS, (2011) and it was revealed that most of the smokers started smoking even before secondary school. The results also revealed the importance of promoting self-esteem. Efforts in smoking prevention should therefore be focused on curbing the initiation of the acts and improving students’ self-worth