Christoph Peters

Virtual Vehicles as Key Technology in Powertrain Development

Dr.-Ing. Christoph Peters, Steffen Braun, Tobias Broß, Robert Bosch GmbH

Automotive industry is facing radical changes. Electrification, autonomous driving and connectivity entail an increase of complexity in powertrain systems. The number of variants increase due to a broad set of E/E architectures. A trend towards vehicle computers and cross-domain controllers is evident.

At the same time, the total number of sold vehicles is stagnating and, hence, engineering resources remain limited. Consequently, there is an urgent demand to increase efficiency in software development. As the world market leader for engine control units (ECU), BOSCH takes up this challenge.

One field with significant potential to gain efficiency benefits is the validation and verification of ECU software. Whereas software was mainly tested on experimental vehicles in the past, a major part of software testing is done on hardware-in-the-loop (HIL) systems as of today. These HIL systems comprise of an electronic test bench, which allows the simulation of vehicle sensors and actuators and thereby replace the experimental vehicle in many test cases. However, substantial investments for HIL systems worldwide are required, hardware adaption for new customer projects is time-consuming and the software developer is bound to a lab environment.

In order to cope with the drawbacks of HIL systems, BOSCH aims to push software development for embedded systems to the next level. The target is to allow software engineers to work everywhere, to reduce feedback time for software errors and to cut investments. The future engineering environment is based on a continuous development approach. Software builds are automatically started, changes are frequently integrated in the target, automated smoke and regression tests are continuously performed and artefacts are delivered any time.

Key technology for a profound software testing are virtual vehicles. These vehicles comprise of a virtual engine control unit, a virtual electric layer, virtual busses and high-quality plant models. A wide range of parameters are thoroughly calibrated which allows software engineers to test their software in individual customer projects. Software-in-the-loop enables cross-domain software development by applying standardized interfaces and allows the simulation of even complex use cases by cloud computing. BOSCH aims to supply a complete tool chain for software-in-the-loop including a cloud interface.

Will non-virtual-vehicle tests become obsolete? No. Final system validation and verification will still be performed on real vehicles for quite some time. Artefacts, however, may also be released virtually on condition that unified standards and methods are applied to ensure credibility of the simulation. BOSCH develops an environment for virtual release which encompasses several inputs such as identification of sensitivities of the model parameters, quantification of uncertainties, verification and validation of the model.