The experiments in the PreGel plant fully entered the operating phase. The whole plant is now governed by the SAFERUN supervisor, which simultaneously manages LGVs equipped with the SAFERUN software and others still driven with the Standard algorithm. The tests allowed verifying the supervisor reliability even in case of hybrid configurations like the one here considered. Such tests are very important since one of the project targets is represented by the implementation of the SAFERUN approach on old plants.
Performance tests executed in the PreGel plant returned quite promising statistics.
Three frequently used paths have been selected as experimental benchmarks: time performances of the SAFERUN strategy have been compared with the ones of the Standard planner. At the beginning of the project, the target time-improvement under realistic operating conditions was posed equal to 4-5%. For the three composite paths considered, the measured time-gain was equal to 9.45%, i.e., it was twice the target value. Such figure is very close to the estimated time-gain obtained by means of simulations, that was equal to 9.75%. The good agreement between simulated and actual results represents an important outcome of the experiments in view of the final test phase, also taking into account that discrepancies are mainly due to known factors like, e.g., particular requests of the customer that were not originally considered during the simulation phase.
Three videos concerning the experimental results can be found here: [1], [2], [3]. In each video a comparison is made between the performances of the SAFERUN and of the Standard planners. Time improvements are evident despite the composite paths are characterized by very long straight segments along which the SAFERUN strategy only allows minor gains.
The tests in the Pregel plant also involved the motion safety. For each segment of the test paths the most critical point was first individuated by means of simulations and, subsequently, a real experiment was made by placing an obstacle exactly in that point, as shown in this video. The experiment was repeated by first using an unloaded LGV and, then, a loaded one. With the SAFERUN algorithm collisions were always avoided.
