eXtremeDB/rt for Automotive Sensor Data Fusion
An ADAS-equipped car is outfitted with many sensors of many types; SONAR, LIDAR, RADAR, optical cameras, GPS and more. These sensors support functions such as traffic sign recognition, lane-keeping (or lane departure warning), adaptive cruise control, parking assist, blind spot detection, collision avoidance and beyond. Let’s not forget internet connectivity for traffic data, maps, and road works.
The view these sensors collectively provide is not static. For example, a car traveling slowly in the city will collapse the information bubble to emphasize points-of-interest, intersections and such. Conversely, a car traveling faster needs to look out farther ahead and, for path prediction, shouldn’t be overly concerned about intersections ahead that the car cannot navigate kinetically because of the nearness of the intersection and the car’s speed.
At its core, this is sensor data fusion. All of this data needs to get to a central location, a database, so that it can be aggregated, correlated, analyzed and acted upon, all in real-time.
Many of these subsystems are time-critical, such as collision avoidance, distance-keeping and path prediction. The logical extension of this is that the database system must be real-time.
A reliable database system built with safety in mind
eXtremeDB/rt is the first commercial-off-the-shelf (COTS) embedded database system to enforce database transaction deadlines, making it uniquely suitable for embedded systems with hard real-time constraints.
Like conventional eXtremeDB, eXtremeDB/rt is an ACID compliant database system that provides services for the storage, retrieval and manipulation of data. The differences lay in the temporal requirements of the managed data, transaction scheduling policies and the timing constraints on transactions.
Watch “Database System Requirements to Achieve Level 3+ Autonomous Driving” presented by McObject at the EETimes Advanced Automotive Tech Forum, or contact us to discuss your project if you need a database for advanced driver assistance systems.
Developers of a real-time database system need to architect the system in such a way that it can guarantee that a transaction will never go past its deadline.
Why should you consider eXtremeDB/rt?
eXtremeDB/rt is founded on eXtremeDB, the first DBMS created specifically for embedded systems, with over 20 years and 10s of millions of systems deployed. eXtremeDB/rt is instrumented to work hand-in-glove with deterministic real-time tasks.
The eXtremeDB/rt kernel — the transaction schedulers, recovery algorithms and the database access API — adjusts to limited operating system services and strives to compensate for their conservative nature by optimizing performance and memory footprint of the database management components.
The eXtremeDB/rt EDF-TM (Earliest Deadline First Transaction Manager) implements a wait-list of transactions, in other words a “transaction queue” in the database kernel. Transaction requests are sorted first on their priority and then within the same priority by deadline.
The Priority Inheritance Transaction Manager exploits the underlying real-time operating system’s scheduling, and may temporarily raise the priority of a thread that is blocking a higher priority thread to let it finish the transaction faster, so it can get out of the way.