Driving with Tentacles - Integral Structures for Sensing and Motion

A Markov Decision Process-based approach for trajectory planning with clothoid tentacles

“…Several forms of tentacles exist: 1) Circular tentacles: In [8], tentacles are represented by arcs of circle. For a fixed speed, all the tentacles begin at the center of gravity of the vehicle and take the shape of arcs of circles.…”

“…The length of tentacles increases with the increase of the speed (Fig. 4) Figure 4: The tentacle's lengths increase with higher speed [8] All the tentacles generated for a given speed are estimated as candidates for the execution of the movement, even if their curvature is not well adapted to the current steering angle of the vehicle.…”

“…For both circular and clothoid tentacles, after generating the tentacles and to guarantee a secure navigation, a security region is generated around each tentacle [8], [14]. This area takes into account the width of the vehicle, plus a security margin.…”

“…Each candidate path is then evaluated through a cost function with several considerations, such as distance and time costs, acceleration and collision checking. The Tentacles method uses a set of virtual antennas that are called tentacles and an egocentric occupancy grid around the vehicle [8]. The occupancy grid expresses the state of the environment surrounding the vehicle and contains the obstacles if they exist.…”

“…The tentacle is a geometric shape that models a possible trajectory of the vehicle and we can find in the literature multiple shapes of tentacles. In [8], the shape adopted for tentacles is circular. The weakness of this approach appears in considering all the tentacles generated for a certain speed as trajectory candidates even if their curvature is not well-suited to the current vehicle steering angle.…”