The investigation on dynamic behavior of electric powered wheelchair during the obstacle avoidance

The increment of the People with Disabilities (PWDs) keep increasing in each year and an urge of assisting these PWDs is demanding. Commercial manual wheelchair eases the mobility of the PWDs but there is side effect for the manual wheelchair users that is pain on shoulder area due to extensive daily propulsion of manual wheelchair for mobility. Therefore, this paper presents an approach towards the autonomous wheelchair whereas concerning the PWDs that have disabilities from upper to lower limbs. These paper investigates the dynamic behaviour of the autonomous wheelchair during the obstacle avoidance. The experiment conducted on the Electric Power Wheelchair (EPW) with two different speed and as a first step before implementing self-navigation system in EPW. The objective of this study is to determine the behaviour of the autonomous wheelchair by using the intervention of human input on EPW. The EPW user will manoeuvre the EPW via joystick with several speed. This study focused on the changes in speed of both left and right tires and yaw angle during the obstacle avoidance. The data will be used as a reference for the development of an autonomous wheelchair during the obstacle avoidance. The data that manoeuvred manually also serve as the human-machine relationship whereas the data will be interpreted into the control systems that will be developed for the autonomous wheelchair. Based on the results, the experience does not affect the manoeuvring skill for both male and female students. Based on the yaw rate, the manoeuvring skills of male and female students could be defined which are 57.9% and 42.1% respectively

Experimental Study on the Effect of Emergency Braking without Anti-Lock Braking System to Vehicle Dynamics Behaviour

An anti-lock braking system (ABS) is a basic skid control system that can prevent the tire from locking up. In an emergency braking situation, a high possibility that the skidding phenomenon can occur without ABS. This incident become worse when an emergency braking is applied either on wet or dry surfaces. Although ABS is crucial to prevent the collision, some vehicles still do not have ABS. This study is aimed to analyse the vehicle’s dynamic behaviour during emergency braking on wet and dry surface condition. The experimental vehicle model is a Malaysian sedan car namely Proton Persona. This instrumented car is equipped with sensors, video camera and data acquisition systems to determine the vehicle’s motion. In the experiment, when the vehicle reached a maximum speed of 60 km/h, the driver push the brake pedal firmly until the car stop. From the experimental results, the effect of emergency braking without ABS is clearly seen at the wheel speed. The tire locked up can be observed when emergency braking was applied on the wet surface. However, for the emergency braking on the dry surface, the tire decreased gradually. This finding shows that without ABS, the vehicle is unsafe and accident can occur. The experimental data from this study also can be used as a guideline to a researcher and manufacturer in the development of ABS and safety system of the vehicl

Speed estimation of the electric-powered wheelchair by proposing the state observer method based on experimental data

Electric Powered Wheelchair (EPW) is a type of wheelchair that uses current for enabling the EPW to move. The navigation of the EPW is influenced by the user itself controlling via the joystick. This EPW help to aid the People with Disabilities (PWD) throughout their daily routine. Issue that encountered by the EPW is that the PWDs with the all of the limbs paralyzed unable to manoeuvre via the joystick. Autonomous wheelchair is the solution for this problem but the problem being faced is determining the optimum wheelchair speed during the obstacle avoidance. The speed that could be determine is the speed of the tires but the speed of both tire could not be taken as the speed of the wheelchair itself. One of the method to determine the speed of the wheelchair is by using the state observer. In this method, both experiment and modelling must be conducted in the same environment and input. This research is a preliminary experiment whereby the Electric Powered Wheelchair (EPW) will be utilized to determine the speed of the both tires and longitudinal and lateral acceleration. Rotary encoders and the gyroscope sensor attached to the EPW to acquire the speed of both tires and the longitudinal and lateral acceleration data respectively. The experiment conducted under the controlled environment to ensure the consistency of the data. The EPW will be experimented on a straight line and obstacle avoidance. This method will be simulated in the Matlab and Simulink under the same circumstances. From the experimental results, it will be used for the state observer method in order to determine the speed of the wheelchair for the development of the autonomous system