The Nexus of Cruise Control

David T. Will, P.E., Mechanical Engineer, Unmanned Ground Vehicle Testing Branch, Automotive Directorate

James R. Adametz, Software Engineer, Analysis Division, Test Technology Directorate


ATC Instrumentation ATC instrumentation used during testing

Will we see the end of tailgating?

ATC partners with FHWA to improve driver safety, mobility and fuel efficiency.

Venturing onto our roads and highways has ramped up stress levels in our everyday lives. New automotive technologies, such as intelligent cruise control, are working to shift some of this stress from man to machine.

Aberdeen Test Center and the Department of Transportationís (DOT) Federal Highway Administration (FHWA) are collaborating to test vehicle platooning at ATCís Automotive Test and Evaluation Facility (ATEF). The partnership is assessing the effectiveness of Cooperative Adaptive Cruise Control (CACC) technology, with the ultimate goal of improving driver safety, mobility and fuel efficiency. This state-of-the-art testing involves five FHWA research innovation vehicles (Cadillac SRXs), with one as the lead vehicle and the remaining four following.

The lead vehicle issues commands to the following vehicles by transmitting modified basic safety messages, through a dedicated short-range communications (DSRC) radio, using the DOT-dedicated 5.9-GHz spectrum. For example, the messages transmit information about vehicle velocity and gap separation time, so that the entire platoon maintains safe speeds and following distances. ATC and FHWA engineers have successfully demonstrated vehicle platooning at 60 miles per hour with a 1-second gap separation time - thatís an 88-foot gap separation distance - between vehicles.

Each vehicle has custom hardware to enable level one automation longitudinal control. CACC hardware is located within the back seat of the vehicle.

When both back seats are upright, the hardware is completely concealed from sight.

Each vehicle has an emergency override pushbutton between the cup holder and gear selector to optimize driver safety and allow manual override at any time. When the button is activated, CACC is disengaged and control is returned to the driver.

ATC installed an instrumentation package on each Cadillac SRX to capture data transferred over the DSRC radios, on the vehicle Controller Area Network (CAN), and via video stream. The instrumentation package has two 12-volt batteries, an electromagnetic interference filter, Platform for Reconfigurable Instrumentation via Modular Expansion Advanced Distributed Modular Acquisition System (PRIME ADMAS), Fortress radio, camera encoder, Ethernet switch with port mirroring, three-axis motion pack, four video cameras and cabling.

ATC used Aberdeen Proving Groundís high performance computing resources to process the various sources of data into a model for posttest analysis. The model was used to mine relevant products to support CACC analytical goals. Google Earth was used to visualize the vehicle and CACC interacting with the environment, DSRC communication and vehicle CAN data.

The current vehicle configuration permits longitudinal control only, for which automatic throttle and brake inputs are applied. Future developments will enable automated lateral control, or steering inputs, of vehicles within platoons to eliminate the need for driver input. Also, FHWA provided ATC with a semitrailer that will be outfitted with CACC technology. The connected truck will be integrated into the FHWA research fleet to study the interaction between small and large platooning vehicles. FHWA will also supply DSRC radios for installation around the ATEF for future vehicle-to-infrastructure development and testing. The ATC-FHWA partnership is a great example of collaboration between federal agencies to share resources in support of our troops.