Mr. Bernat Ferrer, Applus IDIADA, SPAIN
The Adaptive Cruise Control (ACC) is one of the main ADAS functionalities of the automotive industry. It automatically regulates the vehicle speed in order to keep a safe and constant longitudinal distance gap with the vehicles ahead. The development of its requirements and calibration parameters, are key to achieve not only the safety but also the comfortableness of the complete system.
This study considers many of the scenarios that an ACC system is usually challenged to develop and calibrate its main parameters: deceleration with decreasing target speed, target vehicle cut-out, approaching a slower target vehicle, etc. In order to characterise these events, some metrics have been defined, willing to objectivize the vehicle and system performance: longitudinal braking deceleration, acceleration overshoots, jerk, vehicle reaction delays, etc. Signals coming from vehicles instrumented with sensors and tested at IDIADA proving ground tracks, have been acquired for the corresponding analysis. Different vehicle segments and systems were assessed to generate a complete user profile study.
The final vehicles performances were also evaluated subjectively, by experienced drivers under all the above-mentioned driving scenarios. Mainly focused on the longitudinal deceleration behaviour, the different concepts of the brake control (beginning, ending, quality, delays, etc.) have been used as parameters for its comparison with the metrics analysed.
All in all, this study presents interesting and objective methods of evaluation for the ACC systems, supported by the experienced users’ evaluators. This may finally be used as a tool for stages of development and calibration, as the subjective inputs compared with objective metrics provide valuable information of the best system practices.