News & Updates
DADSS Research Program | July 26, 2018
DADSS Research Program Technical Update
Since our last update, the DADSS Program has received and programmed more than 100 Generation 3.1 breath-based sensors and is preparing to integrate them into Pilot Field Operational Trial (PFOT) vehicles. To date, we have several fully-integrated vehicles undergoing some initial road tests to ensure everything is functioning properly.
Our partners at Senseair™ have also completed the development of the first set of Generation 3.2 prototypes, which are a significant leap forward when it comes to sensitivity and the accurate detection of small quantities of alcohol at a distance. The team continues to make progress with the Human Subject Testing, and has collected information which will assist significantly in programming the sensors for more real-life scenarios.
Senseair™ Breath-Based Sensors
The DADSS Lab received over 100 Gen 3.1 sensors for performance characterization in the DADSS Lab followed by integration into the PFOT vehicles. The team has been working on characterizing each sensor at 3 different temperatures (extreme cold, moderate, and extreme heat) using five different alcohol concentrations, a process that typically takes approximately 20 hours to complete for a single sensor. To accelerate the testing process, which would otherwise have taken more than 8 months to complete if tested individually, the team completed key developments that allows for testing of multiple sensors simultaneously in an environment chamber. Once the PFOT road tests are completed (which will involve 12 months of driving in various climatic conditions), the sensors will return to the DADSS Lab for re-characterization and continued performance assessment.
Figure 1 Environmental chamber characterization test rig for multiple sensors.
The DADSS Program is also pleased to report that our partners at Senseair™ completed the development of the first prototypes of the Senseair™ Generation 3.2 breath-based sensors with enhanced sensitivity to alcohol. Initial prototypes were delivered to the DADSS Lab for evaluation, and early results indicate that the Gen 3.2 sensors represent a significant improvement to the previous generation of sensors and bring us a step closer to meeting the DADSS Performance Specifications established for the program. The latest prototype maintains the size of the Gen 3.1 sensors currently being outfitted for on-road testing, making it easy to swap sensors, while significantly advancing the sensor’s “sensitivity,” or its ability to detect small quantities of alcohol at a distance from the driver. In fact, the Gen 3.2 prototype demonstrated breakthrough performance in its ability to passively detect alcohol in naturally-exhaled human breath. Further improvements are being made to the sensor’s performance through enhancements to the electronics systems and alcohol detection algorithm.
Human Subjects Testing
We continue to verify and evaluate the sensors using human subjects in a controlled laboratory setting at McLean Hospital, a Harvard Medical School affiliate. To date, the DADSS Program has worked with over 100 subjects, from whom we’ve collected more than 5,500 blood samples – giving us a valuable trove of data. This data has led to substantial progress in generating the alcohol absorption and elimination curves needed to develop the alcohol detection algorithm across various drinking scenarios.
Recently, the team began testing and evaluating the impact of cigarette smoke on the breath-based sensors and has completed roughly 15 human subjects smoking tests to date. The Program will also be testing the impact of hand sanitizers and low hand/arm temperatures on the touch-based sensors.
Pilot Field Operational Trial (PFOT)
Over the past few months, the DADSS team has been integrating sensors into the PFOT vehicles donated by General Motors. To date, several vehicles have been completed and are undergoing “shakedown testing” (numerous sober driving trips) to ensure that all sensors and instrumentation are fully operational. Each vehicle is instrumented with the following:
- Two Gen 3.1 breath-based sensors
- Custom Data Acquisition System to collect and store all data from sensors
- Wifi/LTE modem to transmit data to database
- Digital Video Recorder
- 2 cameras focused on the driver/sensor interface
- Environmental Sensors module (vehicle cabin temperature, humidity and barometric pressure)
- Vehicle Controller Area Network (CAN) data interface (to collect data from the vehicle’s network such window status, HVAC status, etc.)
While we have not instrumented the remaining vehicles, we have completed the full instrumentation kits, including wiring and hardware.
We look forward to sharing our next technical update with you later this year.
Figure 2 DADSS Senseair steering column sensor.
Figure 3 DADSS Senseair driver door sensor
Figure 4 Vehicle data acquisition system
Figure 5 In-cabin cameras for evaluation of the Driver–Sensor Interface