High-definition maps take automation of driving to the next level

High-definition maps take automation of driving to the next level

Technology News |
By Christoph Hammerschmidt

For a safe and comfortable experience, automated and autonomous vehicles need to accurately perceive, understand and navigate their environment. They also need to anticipate the road ahead to prepare for unexpected events ahead of time – events beyond the range of the vehicle’s sensors. Today’s sensors – ultrasound, radars and cameras –  all have a relatively short range and have performance issues in different weather conditions. To address these issues, advanced driver assistance systems (ADAS) such as Highway Pilot and Predictive Powertrain Control already use digital maps today.

The arrival of automated and autonomous vehicles will require a new level of accuracy and detail obtained through digital, high-definition (HD) maps, as these advanced vehicles need precise information to maneuver through highly complex environments. Consider a highway ramp or a busy intersection, where there is absolutely no room for error. Functions like  highway pilot require highly precise information about the calculated route and path, the centimeter accurate digitalization of lanes, guardrails, intersection areas  and more in order to work safely and smoothly. HD maps can provide this high level of precision.

In short, HD maps provide a realistic representation of the road through information such as lane model, road geometry and traffic signs. They make automated and autonomous vehicles location-aware, positioning them on the road with an accuracy of a few centimeters. They also provide a frame of reference to help the vehicle’s sensors make sense of the surrounding environment. Not only that, they also support the vehicle in planning its path and driving maneuvers by confirming the information relevant for lane changes or highway merges.

The electronic horizon provides a look ahead beyond the car’s sensor range

An electronic horizon translates available map information into usable data for ADAS and automated driving functions. It extends the vehicles ability to anticipate and react to its environment by providing foresight, resulting in a more convenient driving experience. Furthermore, passenger vehicles, as well as commercial vehicles like trucks, traditional engines and especially electric vehicles greatly benefit from this information, as the additional data enables a more fuel-efficient and range-extending way of driving.
Having an

horizon increases the limited range of their sensors by using HD map data. This map data is enriched with dynamic up-to-date information like road works, traffic flow, or weather. With EB robinos Predictor, Elektrobit offers development tools for such electronic horizons to car manufacturers. They can, in turn, utilize digital map data to provide vehicle ECUs a continuous forecast of the upcoming road network by using optimized transmission protocols, which enables and enhances their vehicles’ automated driving functions.

Fig. 1: Improving the driving experience with dynamic, up-to-date information

Streaming HD maps on demand to autonomous vehicles

These necessary HD maps must not only be highly accurate, but also reflect changes in the road immediately, which is why Elektrobit is partnering with TomTom. Having been the first to introduce HD maps commercially in 2015, TomTom today is the first to offer HD map coverage across Europe, North America, and Asia. Via its AutoStream service, TomTom delivers up-to-date HD maps by streaming the latest map data to autonomous vehicles from the cloud.

With this streaming service, drivers can be sure that all possible incidents on the road ahead are taken into consideration and, when necessary, calculated routes can be adjusted accordingly. TomTom AutoStream comes as a full solution, including an on-board software component with smart logic that significantly simplifies and shortens development time for companies building autonomous driving systems. Its flexible design allows customizing the map data stream based on criteria such as sensor configuration and horizon length.

Fig. 2:  Electronic horizon with EB robinos Predictor
and TomTom AutoStream

How the electronic horizon provides current information to all ADAS ECUs

To deliver an electronic horizon to ADAS electronic control units (ECUs), both an electronic horizon provider and an electronic horizon reconstructor are needed.

The former predicts the upcoming driving path by considering the current vehicle position, driving conditions, and road data. Based on the calculated path, the electronic horizon provider will create a so-called electronic horizon tree out of the HD map data and fuse the dynamic data into it. Based on the predicted paths, multiple trees are generated, so that an up-to-date electronic horizon can be quickly provided should the vehicle leave its current path. This data is then distributed over the vehicle’s network to all attached ADAS ECUs where they are received by an electronic horizon reconstructor. This element converts the data stream back to a data structure that can be processed by the ECU to execute its tasks.

The standard data format for the electronic horizon tree is called ADASIS. To enable and enhance automated driving functions, vehicle manufacturers want to access and use the information provided by navigation systems, such as map data, vehicle position and speed. Today, however, navigation map databases are only accessible to navigation applications and stored in the proprietary format of the navigation system. The overall aim of the ADASIS forum is to define an appropriate information exchange interface to access this data. It was defined and is constantly refined by the ADASIS consortium, in which both TomTom and Elektrobit are members. Elektrobit leverages TomTom’s HD map data to develop the first reference implementation of the ADASISv3 standard, which fulfills the requirements for automated and autonomous driving.

A comprehensive approach for predictive driving

An electronic horizon realized with EB robinos Predictor and based on TomTom’s AutoStream and HD maps enables an autonomous vehicle to plan a predictive driving strategy. By matching the map data from the cloud to the environment data provided by on-board sensors, the system can improve its localization and its perception of the surroundings. This comprehensive information is critical to localization, perception and path planning, which ensures that the respective automated driving function can work sufficiently

Overall, an integrated solution combining HD maps and horizon software paves the way for vehicles to see beyond their sensors and enables a safe, comfortable and fuel-efficient automated driving experience.

About the authors:

Tomaso Grossi is Product Marketing Manager, Autonomous Driving at TomTom.

Christian Hering is Product Manager EB robinos at Elektrobit Automotive.


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