A look into the origins of the Soft Car 360® and GST™

This year DRI celebrates the 10th anniversary of the first sale of the Guided Soft Target (GST) surrogate vehicle target system.

The GST test system consists of the Soft Car 360 – an impactable dummy vehicle target attached to a low-profile robotic platform designed to be run over by vehicles. In this article we will delve into the history of this solution, which has had a significant impact of the development of active safety systems globally.

The GST story starts in 2007 when crash avoidance technologies, such as Automatic Emergency Braking (AEB), were still in their infancy and so too were the systems to test them. A variety of targets, ranging from simple radar reflectors to partial vehicle representations (both static and dynamic), were developed to aid in the evaluation of rear end collision avoidance and mitigation systems, but these had limitations restricting approach speeds and angles, as well as lateral offsets. Additionally, some of the dynamic systems required the presence of other vehicles to tow the targets, or suspend them from above, which could sometimes adversely affect the performance of the vehicles under test.

It was at this time that DRI collaborated with NHTSA (National Highway Traffic Safety Administration) and Honda R&D on the ACAT (Advanced Crash Avoidance Technologies) project. The project aimed to develop practical methods for evaluating the effectiveness of emerging ADAS technologies. A key phase of the project was to establish the test requirements in order to conduct full-scale testing of the technologies.

The project identified three key vehicle-to-vehicle scenarios that would need to be tested, which were head-on, rear end and crossing paths. These tests necessitated a dynamic solution that was strikable from multiple angles that

• did not damage to the vehicle under test;
• did not present a safety risk to test personnel;
• was easily reconfigurable and enabled close coordination of vehicles with regard to conflict conditions such as closing speed and angle, and
• could easily be reset after impact for further testing

The solution was the GST system. Through this project, DRI became fundamental in finding ways to help the industry test and develop first-generation collision avoidance systems that have since been developed into today’s technologies.

The initial development of what would become recognizable as the GST system used a simple vehicle target constructed from foam, fitted to a first-generation version of the GST platform, which was affectionately known internally as the ‘Turtle’. It was the first self-propelled dummy vehicle target that could be safely run over, providing unrivalled testing flexibility. Designed initially for detection by lidar, the system’s visual representation of a vehicle and its radar reflectivity were less relevant. The entire system was designed and manufactured in-house at DRI, including the platform’s navigation and control system.

DRI recognized that the appearance and durability of the target needed to be improved to be useful to manufacturers using camera and radar systems and this formed the core development path for the following few years. A project with IIHS (Insurance Institute for Highway Safety) in 2011 and feedback from other industry experts identified a demand for stable radar reflectivity, which resulted in the introduction of a new reflective material for the Soft Car 360. Other developments included enclosing the foam skins in vinyl fabric “pillowcases”, which allowed the application of photorealistic graphics and increased durability and realism. The result was a first-generation version of the Soft Car 360 that we know today.

DRI’s involvement in these industry projects led to the development of solutions that are now in use globally to thoroughly test ADAS technologies. Worldwide adoption of standardized tests that rely on our equipment is helping to provide safety ratings of new vehicles to educate consumers and improving road safety.

In 2012 DRI developed what became the first commercially available GST that incorporated all the various features to make it representative to a variety of sensor systems. Later that year, DRI began its partnership with AB Dynamics to further develop the product and the first unit was delivered to an Asian OEM in 2013.

In 2014, DRI developed the second generation GST in collaboration with NHTSA. This project involved reducing the radar reflectivity of the platform and increasing the acceleration and top speed, to cater for the growing variety of tests being carried out. There was also a heavy-duty version developed for trucks. In 2018, AB Dynamics introduced the MK2 GST platform, bringing improvements to the market, such as a lower overall profile, 100 km/h top speed and improved path following.

The collaboration between AB Dynamics and DRI proved to be a great success resulting in the GST’s approval for use by Euro NCAP and NHTSA as its Global Vehicle Target in 2018. The relationship further strengthened when DRI joined the AB Dynamics Group through an acquisition in 2019.

DRI and AB Dynamics are continuing to jointly develop the system as driver assistance technology develops. One of the next big steps in active collision avoidance technologies is likely to come from increased connectivity. The ability for a vehicle to communicate with infrastructure and other vehicles around it increases awareness of potential dangers and the time to react. The integration of connectivity, or V2X (Vehicle-to-Everything), will significantly impact the testing landscape. AB Dynamics is participating in the SECUR project (Safety Enhancement through Connected Users on the Road), which aims to create a coherent proposal for V2X testing and assessment protocols for Euro NCAP. AB Dynamics’ key input into the project is to help define a specification for connected targets to support V2X testing in the future.
Watch this space for further developments.