Software Defined Car – Flexible Software Architecture for the Electric Light Vehicle ACM CITY

Electric vehicles should be flexible and adaptable. ESK researchers are developing an ICT infrastructure that enables individualized user interfaces and multimodal vehicle use.

Future inner-city electric vehicles should be more cost-effective by maximizing utilization and scaling the design down to the most essential features. This can be achieved if minimally-designed vehicles are nevertheless flexible and adaptable. In other words, they need to be versatile enough for a wide range of uses, whether in the morning as a taxi, in the afternoon for car sharing or in the evening for innercity logistics such as pizza delivery.

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The ACM CITY is the ideal mobility solution for the inner city. The energy-efficient lightweight vehicle can be used adaptively for Sharing, Logistics and Ride-hailing – reducing traffic density, parking time, CO2 emissions and operating costs.

High Utilization through Flexible Applications Leads to Efficient Use of the Vehicle

Using one and the same vehicle for different purposes requires that they have their own set of functions, such as driver’s logbooks and invoice printers, in addition to an individual user interface. As part of the »Adaptive City Mobility« project, Fraunhofer ESK addressed this issue by researching and developing an open information and communication technology (ICT) vehicle architecture that enables the multimodal use of small electric vehicles.

This architecture will be further developed, validated and tested in prototype vehicles in the follow-up project »Adaptive City Mobility 2« (ACM-2). In the year 2015 the German government selected ACM to become one of the electric mobility lighthouse projects. These projects are highlighted to show their ability to make important contributions to advanced technology in the area of electric mobility.

© Fraunhofer ESK

Front- und Schrägansicht der ACM Designstudie.

The vehicle ICT architecture is planned so that the three target groups – manufacturers, operators, and users – are provided maximum adaptability and a scaled-down vehicle software design effort. The capability to configure the operation of the vehicle and the scope of the infotainment applications to meet the needs of the respective purpose means that fleet operators adapt the vehicles on their own for instance. This provides flexibility in daily operation and enables new marketing strategies.

Central Electronic Control Unit for Infotainment and Additional Vehicle Functions

The heart of the ICT infrastructure for small vehicles is a central ECU that contains all of the safety-critical and non-safety-critical functions. Special attention must be paid to protecting the safety-critical functions. In ACM this was achieved prototypically by separate hardware and within ACM-2 this will be enabled by using virtualization that ensures a reliable and predictable execution process. Moreover, in order to reduce the energy consumption of the in-vehicle ICT network, researchers are working on a process that makes it possible to estimate the energy consumption in the early phases of development. Energy efficiency for applications that operate all the time is an especially important issue for electric vehicles.

In addition to well-established interfaces, the central ECUs will also be equipped with UMTS, WLAN and car2x communication capability. The central ECU features its own Linux-based partition on which a wide range of apps can be made available. In this environment, the so-called vehicle service plays a key role in allowing existing vehicle functions or information to be easily integrated in external applications.

The concept of three different protected areas in the central electronic control unit affords a maximum degree of flexibility: a protected real-time area for the vehicle’s driving functions, an open area for the operator of the service in which apps are installed and an area for interaction with the user’s smartphone.

© Fraunhofer ESK

ICT architecture in the software-defined car


Thanks to the flexible software architecture developed by the Fraunhofer ESK, the ACM CITY can be easily and quickly adapted to different application scenarios.

Bring Your Own Device – the User Interface

Due to the short development cycles for mobile devices and the desired flexibility provided by apps that can be retroactively installed, the vehicles are operated with tablets or smartphones. The apps can retrieve information such as speed, position and battery status in addition to operating the climate control system or battery charging process. This gives users the opportunity to individually design their own interface and bring own functionality into the vehicles. The smartphone can also be used to unlock the vehicle and authenticate the driver.

Flexible ICT Infrastructure for Future Vehicles

The challenge for the ESK researchers is opening up the ICT infrastructure for various application concepts while ensuring reliable operation of the safety-critical driving functions. The only path to ensuring flexible and therefore high utilization of the e-vehicle is to create a simple, streamlined development environment for the control and application software. This is made possible by the special modular ICT architecture of the central electronic control unit.

Field Tests

Within the ACM-2 project, researchers will create several vehicle prototypes with the open and flexible ICT architecture and test its functionality. This will require validation testing, a detailed functional test of the ICT architecture and a broader functional scope for the field test.

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Adaptive City Mobility (ACM) presents an emission-free eMobility system for cities: A new approach to the urban transport of people and goods in the future – energy-efficient, resource-conserving and environmentally friendly!

These projects are supported by the German Federal Ministry for Economic-Affairs and Energy.