S.G. Ponnambalam et al. (Eds.): IRAM 2012, CCIS 330, pp. 252–262, 2012.
© Springer-Verlag Berlin Heidelberg 2012
Cordless Cart Follower for Wheelchair User
Noridayu Abdullah Sani, Syed Sahal Nazli Alhady bin Syed Hassan,
W.A.F.W. Othman, and Suardi bin Kaharuddin
School of Electrical & Electronic Engineering, Engineering Campus,
Universiti Sains Malaysia, 14300, Nibong Tebal, Pulau Pinang, Malaysia
noridayu.as@gmail.com, {sahal,eeamirfuad,suardi}@eng.usm.my
Abstract. A wheelchair bound person requires the freedom of upper limb body
movement to move around. Any attachment to the wheelchair in the form of
luggage will restrict the performance of such person to navigate the wheelchair.
Poor navigation of a wheelchair might, in the worst case scenario, lead to an
accident that would cause injury to the person. In addition, the durability of the
wheelchair might also be affected if the weight put onto it is increase. In this
project, a cart follower is introduced to overcome the above mentioned
problems faced by wheelchair bound person who need to carry around their
luggage. The cart follower has been specifically designed for wheelchair bound
persons to help them carry around their luggage. It will automatically track and
follow the wheelchair without any attachment or cord between the wheelchair
and the cart. Microcontroller, sensors, motors, and servo are used in order to
achieve the objective. A CMUCam3 camera with vision sensors is used to track
an object, which is in this case, a predefined color from an image pattern. The
cart will only move when the configured color is detected and stops when there
is no configured color detected. The cart will move backward in decreasing
speed from 100 to 70 percent duty cycle if the infrared distance sensor detects
an obstacle or if the wheelchair is in the range of 10-28cm a head and then
maintains a distance of 28cm as the wheelchair is moving backward. Pulse
Width Modulation (PWM) is applied to control the speed and a servo motor is
used to control the angle rotation of the cart.
Keywords: Cordless cart follower, CMUCam3 camera, distance sensor.
1 Introduction
Theoretically, the cordless cart follower might seem like a normal and typical bulky
luggage commonly found in the market. But the intelligent capability applied onto the
cart sets it as different from the others. This cart follower is specifically designed for
the wheelchair bound to help them carry around their luggage. It will automatically
track and follow the wheelchair without any attachment or wire between the
wheelchair and the luggage. In order to archive the objective, the project required
development in electronic and mechanical area.
The cart consists of microcontrollers, several sensors, motors, and actuators to
make the cart follow the wheelchair without losing the track. One of the sensors used