Vehicle Dynamics
ADS Test Data Interface
Originally built during an SBIR project with NHTSA, S-E-A created the Automated Driving Systems (ADS) Test Data Interface (TDI) to bridge the gap between vehicle controls and control inputs for vehicles without conventional driver inputs (no pedals or steering wheel). Despite not having conventional controls available to the driver, these vehicles still need to perform standardized testing (such as FMVSS 126) to be sold on the market. NHTSA and other testing agencies were interested in a method by which drive-by-wire vehicles could be controlled via passed control inputs, while ensuring safe operation and preventing misuse.
For this work, the S-E-A Automated Test Driver (ATD) was used as a basis for providing commands to the vehicle, which was equipped with a Dataspeed By-Wire kit. With connection via the vehicle OBD2 port and communication following the latest ISO communication protocols, the system can communicate with the vehicle’s onboard control systems. In order to ensure the safety of operation and prevent penetration from outside sources, a safety layer consisting of a handshake between a client in the control input and a server on the vehicle side was implemented. A proof of concept implementation is shown in the image below, where the Automated Test Driver, Test Data Interface (TDI), and GPS/IMU are all shown.
The output of the system when this handshake is complete and Drive By Wire, Steering Input, and Brake Inputs are all enabled is shown below.
In addition to being proven through completion of three different FMVSS maneuvers using inputs from the ATD, the TDI was additionally put through penetration testing by a partner firm to ensure that the safety protocols at the client/server handshake were sufficiently robust. Providing a safety layer was an important deliverable for ensuring that by-wire operation is safe for the test operator and the eventual consumer.
When vehicles lack conventional controls, driving the vehicle to and from testing sites and through FMVSS procedures designed around conventional steering, throttle, and brake inputs becomes a challenge. With S-E-A’s design of a Test Data Interface for ADS, one key step in testing Level 4 and 5 vehicles has been completed. Once the automotive industry has standardized communications for control inputs, future work to bring a commercialized TDI to market will be possible.
More information can be found in our SAE publication 2023-01-0828.
Have questions about how S-E-A’s Vehicle Dynamics group can help solve your unique testing need? Contact us today!