By DAMIEN GAYLE
A wheelchair with legs that can climb steps and negotiate obstacles has reached the prototype stage in Japan.
Engineers at the Chiba Institute of Technology in Narashino have developed a robot wheelchair that can make a variety of movements using four-wheel drive and five axes of motion.
Like any other wheelchair, it rolls along on its wheels but, if a step or ditch gets in the way, the wheels transform into legs to carry the user over.
The promising invention has important implications for disabled access. Currently buildings and areas with steps and uneven surfaces are practically off-limits to those in wheelchairs.
The user controls the device by means of a joystick and its robot brain automatically assesses the surrounding terrain and moves appropriately - even adjusting itself to keep ensure the seat remains level.
Sensors on the feet of the wheelchair detect if there are any obstacles nearby, Professor Nakajima told DigInfo.tv. Using its sensors in combination it can assess the size of an obstacle and how to negotiate it.
Even if the sensors fail to detect an obstacle in advance and the wheels touch it, the torque can be automatically varied as a backup.
'In this way, the robot can detect the road surface reliably,' Professor Nakajima said. 'If a sensor detects a step, the robot calculates whether it can lift that leg.'