Ranking of "Collision-Free" Cars

Subaru and Volvo take top honors

Aug 12, 2014
Collision-Free Car Test Team, Nikkei Automotive Technology

Nikkei Automotive Technology magazine evaluated low- and mid-speed recognition (vehicle and pedestrian) and braking functions in automobiles from nine manufacturers equipped with autonomous braking systems. This was the first comparative evaluation in Japan of autonomous braking for pedestrians. Overall, models from Fuji Heavy Industries Ltd. of Japan (Subaru) and Volvo came out on top, with AAA ratings. We analyzed the data to see just what different manufacturers do differently, and probed their design philosophies.

Collision avoidance performance at low and medium speeds (mainly 20 km/h to 50 km/h) was evaluated, for both stationary vehicles and pedestrians. As the test included pedestrians, different vehicles showed widely different recognition capability especially for human figures. Infrared laser and millimeter-wave radar systems, however, were not capable of sensing pedestrians, resulting in lower scores.

EyeSight (Ver. 2) from Fuji Heavy Industries Ltd. (FHI, the automaker of Subaru) of Japan scored the highest, followed by the City Safety system from Volvo; both earned AAA ranks.

Nikkei Automotive Technology magazine tested autonomous braking functions on vehicles from nine manufacturers, on the Saitama Institute of Automotive Technology test course at the end of March 2014. Simulated targets were erected at the end of a straight stretch of paved road, for both parked vehicles and pedestrians, and the test vehicles driven toward the targets at a constant speed (see page 14 for outlines of test and scoring criteria). In principle, four speeds were used: 20 km/h, 30 km/h, 40 km/h, and 50 km/h, but other speeds were used as required for specific test vehicle cases. The maximum speed at which the collision was avoided was scored (under about 20 km/h, 30 km/h, 40 km/h, or 50 km/h), independently for vehicle and pedestrian targets, and the total used to produce one of three levels of performance.

Of the nine vehicles, the XV sport utility vehicle (SUV) mounting the EyeSight system, and the V40 compact hatchback with the City Safety system, both managed to stop without collision at a speed of about 40 km/h for the vehicle target (Fig. 1), and at about 30 km/h for the pedestrian target. The total score for autonomous braking for both vehicles was five or more, putting them both in the AAA rank.

Fig. 1  XV testing
Fig. 1 XV testing
Test vehicle was driven at about 30 km/h toward the pedestrian target. Autonomous braking activated, and the vehicle stopped about 1 m short.

The EyeSight system in particular avoided collision at about 50 km/h for the vehicle (four points) , and about 40 km/h (three points) for the pedestrian, for a total of seven points. The Volvo City Safety system, also ranked AAA, was scored three for the vehicle and two for the pedestrian, for a total of five, well behind the front-runner and establishing the EyeSight autonomous braking system as the clear winner in the competition.

Two earned the AA rank, with at least three points: the Emergency Brake system from Nissan Motor Co., Ltd. of Japan in the X TRAIL, and the Driving Assist system from Bayerische Motoren Werke AG (BMW) of Germany, in the firm’s M5. Both systems are simple designs using only a single-lens camera to detect obstacles, and gained three points by avoiding collision with the vehicle target at about 30 km/h, and the pedestrian at about 20 km/h. These results illustrate the recognition performance of the single-lens camera clearly.

The autonomous brake functions from five manufacturers were ranked A, with less than three points. Toyota Motor Corp. of Japan was the only one to receive two points, for its Pre-Crash Safety System (millimeter-wave), using a Crown Athlete test vehicle. It avoided collision with the vehicle target at about 30 km/h, but since it was unable to avoid the pedestrian target did not receive AA rank.

The remaining four systems were unable to avoid the pedestrian target, but received one point each for avoiding the vehicle target at about 20 km/h or less. They were the Radar Brake Support from Suzuki Motor Corp. of Japan (Wagon R test vehicle), the Smart Assist from Daihatsu Motor Co., Ltd. of Japan (Tanto test vehicle), the City Brake Active System from Honda Motor Co., Ltd. of Japan (FIT Hybrid text vehicle), and the City Emergency Brake/Front Assist Plus from Volkswagen AG (VW) of Germany.