A Dynamic Localized Adjustable Force Field Method for Real-time Assistive Non-holonomic Mobile Robotics

Providing an assistive navigation system that augments

rather than usurps user control of a powered wheelchair

represents a significant technical challenge. This paper

evaluates an assistive collision avoidance method for a

powered wheelchair that allows the user to navigate safely

whilst maintaining their overall governance of the platform

motion. The paper shows that by shaping, switching and

adjusting localized potential fields we are able to negotiate

different obstacles by generating a more intuitively natural

trajectory, one that does not deviate significantly from the

operator in the loop desired-trajectory. It can also be seen

that this method does not suffer from the local minima

problem, or narrow corridor and proximity oscillation,

which are common problems that occur when using

potential fields. Furthermore this localized method enables

the robotic platform to pass very close to obstacles, such as

when negotiating a narrow passage or doorway.