Revolutionary self-driving wheelchair also affordable

July 9, 2018 - Coimbatore, Tamil Nadu, India

For many long years, wheelchair users in India have wished for a chair that can safely drive to their destination without their constant control and concentration. The product is available in other countries, but very expensive for most of the Indian market.

Now three Bachelor of Technology students at Amrita Vishwa Vidyapeetham, Coimbatore Campus have successfully created an affordable prototype. They were mentored by Dr. Rajesh Kannan Megalingam, an Assistant Professor of Electronics & Communications and Director of the Humanitarian Technology Labs.

Named the Self-E, the wheelchair navigates its own path and avoids obstacles that are both stationary and moving. It uses a Robotic Operating System (ROS) for the autonomous navigation, which first creates a map of the surrounding environment using a laser sensor. That information along with the static and dynamic objects is then displayed through a smartphone app. The user can touch any point on the generated map, and the wheelchair will drive to that place automatically.

In contrast to the quite expensive price tag for self-driving wheelchairs in other countries, the young inventors at Amrita have managed to produce the prototype below $1,500 USD. Such a comparatively low cost promises to be a boon to wheelchair users in India once the technology is widely available.

“The Self-E is unique in the sense that it is the first self-driving wheelchair in India built by the research lab of a university without any collaboration with foreign universities or companies,” explains Dr. Megalingam.

“It now needs to be tested in different environments like hospitals and airports with patients and wheelchair users. The current version is a successful prototype and, with the help of Technology Business Incubator of Amrita Vishwa Vidyapeetham, we hope to commercialize the product.”

The three students who invented the Self-E wheelchair–Chinta Ravi Teja, Sarath Sreekanth and Akhil Raj–have been working for the last two years as junior researchers at the Humanitarian Technology Lab.

“The self-driving wheelchair allows patients to be easily transported from one place to another anywhere at a hospital, airport or even a home,” says Chinta Ravi Teja.

“If patients are able to operate a smartphone, they are relieved from the continuous use of traditional joystick to steer the wheelchair. With a simple touch on the map displayed on the mobile screen, the wheelchair takes them to the destination. They can have complete control over the wheelchair without anyone’s help. If, on the other hand, some patients have a problem in using a smartphone, a person can use the Android App to transport them without the need to physically push the wheelchair.”

The Self-E wheelchair addresses a critical need. In a hospital or airport, people with mobility issues depend on a manual wheelchair along with people to push the wheelchair and this hinders their freedom of movement.

If they use a powered wheelchair with joystick control, they need to manipulate the joystick and steer the wheelchair all the way to the destination. Self-E, in contrast, maps the surrounding environment, including dynamic and static obstacles such as people, walls, pillars, tables, chairs, etc. by using a laser sensor called LiDAR.

The map is automatically loaded onto an Android smartphone or tablet through a specially developed app. Self-E’s autonomous operation allows users to relax and sip a cup of coffee, read a newspaper or chat with friends as the wheelchair takes them to their desired destination point on its own. The Self-E wheelchair can also be used at such places as homes, retirement communities, assisted living communities, restaurants, and washrooms.

Sarath Shreekanth says, “The development of an algorithm for the self-driving wheelchair to perfectly map the environment and plan the proper path to the destination was the first challenge. We used the Robotic Operating System (ROS) to address this successfully.

“The second challenge was avoiding dynamic obstacles like people and pets while the Self-E was navigating to the destination. The LiDAR sensor along with the Robotic Operating System helped by detecting such obstacles and recalculating a new path to the destination. Developing a cost efficient self-driving wheelchair was another issue. We used a single LiDAR sensor to keep the overall costs of the product as low as possible. Making the Self-E enter and exit through a door was a difficult task but we could succeed in this after several tunings of the system.”