Vision-based adaptive assistance and haptic guidance for safe wheelchair corridor following.

We devise a low-cost vision-based assistance scheme for wheelchair corridor navigation.Progressive assistance is activated if the wheelchair is in danger, as the user drives manually in a corridor.Natural image features that can be extracted robustly in real-time is employed in order to design the assistive controller.Optimal force feedback, also designed from visual information, is provided using a haptic joystick in order to increase intuitiveness of the system.Experimental results show the feasibility of the system for Commercialization. In case of motor impairments, steering a wheelchair can become a hazardous task. Joystick jerks induced by uncontrolled motions may lead to wall collisions when a user steers a wheelchair along a corridor. This work introduces a low-cost assistive and guidance system for indoor corridor navigation in a wheelchair, which uses purely visual information, and which is capable of providing automatic trajectory correction and haptic guidance in order to avoid wall collisions. A visual servoing approach to autonomous corridor following serves as the backbone to this system. The algorithm employs natural image features which can be robustly extracted in real time. This algorithm is then fused with manual joystick input from the user so that progressive assistance and trajectory correction can be activated as soon as the user is in danger of collision. A force feedback in conjunction with the assistance is provided on the joystick in order to guide the user out of his dangerous trajectory. This ensures intuitive guidance and minimal interference from the trajectory correction system. In addition to being a low-cost approach, it can be seen that the proposed solution does not require an a-priori environment model. Experiments on a robotised wheelchair equipped with a monocular camera prove the capability of the system to adaptively guide and assist a user navigating in a corridor.