High-speed vehicle lane changes in heavy traffic are potentially dangerous whether the situation unfolds during a daily commute or on a closed test track. But when the driving mayhem materializes in cyberspace, no one is at risk.
"A lot of traffic situations could be tested in the real world, but they create situations that are very dangerous to the test drivers. For more complex situations involving multiple vehicles and corresponding drivers, reproduction in a real-world setup is a very big effort in terms of time and money," said Herbert Schuette, Director of Applications/Engineering for dSPACE GmbH.
Being able to perform high-stakes vehicle maneuvers in the virtual world is possible via a new road traffic simulation model, recently added to dSPACE's Automotive Simulation Models (ASM) product line. This latest traffic module helps technical specialists develop and test pre-crash systems such as seatbelt pretensioners, as well as driver assistance systems such as advanced cruise control (ACC). For example, by using a hardware-in-the-loop system and the ASM Traffic Module, a test engineer can craft a traffic maneuver around an ACC-equipped vehicle.
A typical case scenario to test the switch from cruise control to distance control of an ACC controller: The cyber-vehicle's ACC is set at a constant speed while several other automobiles are traveling in succession on a separate lane. "When the vehicle under test comes within a certain distance of the vehicles in the chain, one of the cars is triggered to do a cut-in maneuver. The simulated sensor now recognizes the slower vehicle and the ACC controller should control the distance to it," noted Schuette.
The simulation model enables a test vehicle to be equipped with radar sensors while surrounded by as many as 15 vehicles. "For typical test scenarios, two to eight vehicles are generally sufficient to simulate traffic circumstances, like a crossing pedestrian, vehicles cutting in and out of traffic, passing a chain of vehicles, or oncoming traffic. If in the future there is a demand for more vehicles to be simulated, the traffic module can be extended," said Schuette.
In designing and developing the new traffic model, dSPACE engineers needed to create a set of relevant test scenarios as well as devise a comprehensive and convenient user interface. "The interface and the underlying model functionality had to be powerful enough to enable test engineers to develop test scenarios of nearly unlimited complexity," noted Schuette.
Developing a 3-D sensor model was a challenging implementation endeavor for dSPACE engineers. "In the current version, the vehicle can be equipped with up to 10 sensors. These sensors can be placed at any point in the vehicle with arbitrary orientation, and each sensor has its own parameterization. Additionally, the sensor models provide multiple distances and the relative velocity for detected objects," explained Schuette.
Future upgrades to the ASM Traffic Module will match user needs. "Most likely, the sensor model will undergo further refinements—surface reflection properties of other vehicles, extended lane handling, and obstacle/guardrails simulation. Another item will be the adaptation of ASM Traffic to lane departure warning or lane-keeping systems. And car-to-car communication with intelligent fellow drivers and camera-based driver assistant systems will become more important in the future," according to Schuette.