Simulation Results

ostacoli unsafe curva 2 ESEMPIO

Before the actual sperimental phase begins, the new speed planner has been tested through the execution of numerical simulations, in order to verify its performances in realistic scenarios. Comparisons w.r.t. the performances of the planner currently used by Elettric 80 have shown that the new strategy allows for travelling times reductions in the range from 10% to 30%. The highest gains are obtained with very sharp curves, for which it is common to reach peaks of 60%.

The video, that could be seen here, shows a comparison between the two planning methods for one of the test paths when the same safety area is used.

Simulation tests have also proved that such improvements do not influence safety. To this purpose, random obstacles were placed along the vehicle path: in all cases, the vehicle correctly stopped before any collision could occur. An example of the test procedure is shown in this video in which a sigle obstacle causes a safe stop of the SAFERUN planner.

Further simulations have been carried out to see if the old planner might emulate the results of the novel one by adopting increased average speeds, but all generated trajectories were unfeasible. In some cases the LGV was not able to follow the assigned path, in others it collided with the obstacles placed along its way. In further experiments, the range of the safety sensors was increased in order to recover the safety conditions even when using the old planner with increased speeds. Collisions were avoided, but the vehicle continuously stopped because false positives were detected. A comparison between the two alternative situations is shown in two videos, the first one demonstrates that the standard planner lead to lose safety with the same area of the novel planner, the second one shows that with the large area it reveales false positives.

The general premises are therefore promising: the novel planning strategy allows higher performances strictly guaranteeing safe operating conditions. The SAFERUN project is thus mature to enter the implementation phase. The developed code is being translated into the C language and brought on the controller of the demo LGV owned by Elettric 80 for the execution of the first experimental tests.

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