Shared control of autonomous vehicles based on velocity space optimization

This paper presents a method for shared control of a vehicle. The driver commands a preferred velocity which is transformed into a collision-free local motion that respects the actuator constraints and allows for smooth and safe control. Collision-free local motions are achieved with an extension of velocity obstacles that takes into account dynamic constraints and a grid-based map representation. To limit the freedom of the driver, a global guidance trajectory can be included, which specifies the areas where the vehicle is allowed to drive in each time instance. The low computational complexity of the method makes it well suited for multi-agent settings and high update rates and both a centralized and a distributed algorithm are provided that allow for real-time control of tens of vehicles. Extensive experimental results with real robotic wheelchairs at relatively high speeds in tight scenarios are presented.