21. Internationales Stuttgarter Symposium

Table of Contents

1. Hybrid II

   1. Frontmatter

   2. Energy Cost Based Vehicle Hybrid Control and Analysis Technique

      John Shutty, Dmitriy Semenov

      Abstract

      A novel method of analyzing and controlling hybrid systems has been developed. Utilizing engine operating maps along with hybrid electrical system efficiency data, the actual cost or savings of fuel related to the generation or usage of electric energy can be calculated. These calculations can be used to analyze a vehicle’s operation, or they can produce optimized Electric Fuel Savings (EFS) or Electric Fuel Cost (EFC) maps which can be used for the supervisory control of a hybrid propulsion system. This method is similar in concept to the well-known Equivalent Consumption Minimization Strategy (ECMS) but has some unique attributes. The operating strategy is less computationally demanding than ECMS and tends to be more intuitive which lends itself well to system analysis and calibration.

   3. RT – Revolutionary Technology

      Simon Wallner, Klaus Schrewe

      Abstract

      For the new Rosenbauer Revolutionary Technology (RT) fire truck, the developers at Rosenbauer didn’t just improve an existing vehicle, instead reconsidered the entire fire truck concept. The objective was to conceive the future of firefighting vehicles. And finally this goal was achieved: The groundbreaking innovations make the RT the most modern emergency vehicle in the world. The firefighting truck of the future. This paper take a look on the Rosenbauer RT, and an insight into the history of the project from the first prototype to the serial product. It shows the architecture of the hybrid drive train and the advantages of the system architecture including the degrees of freedom, which are possible with a hybrid drive train.

      In the second part of the paper, the Range Extender and the aftertreatment system get a spotlight. Explaining why this special combustion engine is necessary in a heavy-duty hybrid firefighting truck and how it is possible to fulfill the emission standard in a not common project.

   4. Holistic Approach for the Design and Dimensioning of a Hybridized Heavy-Duty Truck

      Patrick Noone, Nicolas Hummel, Alexander Kuznik, Christian Beidl

      Abstract

      This paper describes a methodology for the design and dimensioning of a hybridized powertrain for heavy-duty vehicles. It is based on a two-stage approach in which a suitable hybrid configuration is first found by pure simulation with the aid of a genetic algorithm and then a multi-criterial optimization is carried out on the Engine-in-the-Loop test bench with the inclusion of DoE. In this process, the electrical components of the hybrid powertrain are optimally dimensioned. In principle, the presented methodology is open to changing boundary conditions and target variables, so that it is ideally suited as a tool for the design of hybrid powertrains. A variable level of detail can be specified to achieve an optimal result for each application. In addition, an exemplary optimization is presented herein, in which initially only the reduction of the CO₂-equivalent during operation is included as a cost function. In the second step, nitrogen oxides and particulate emissions are additionally considered. The example is based on a real existing and previously measured long-haul truck.

2. Virtual Testing

   1. Frontmatter

   2. Design of a Simulation Environment for Testing the Control of Electric Power Steering Systems

      Marcus Irmer, Hermann Henrichfreise

      Abstract

      The control of the driver’s steering torque of electromechanical power steering systems is state of the art. However, due to nonlinear characteristics and degrees of freedom of the plant which are unconsidered in the control design, the challenge still is the robust implementation of this control approach. Therefore, a new control approach was presented in previous papers that solves this robustness problems. In this paper, the control approach is analyzed in an augmented simulation environment. It is demonstrated that this control approach ensures a high robustness even when simulating critical driving situations. In addition, the control approach allows a nearly unconstrained design of the steering feel.

      Based on a detailed nonlinear model of an electromechanical power steering, a reduced linearized model for the design of an optimal state space controller and an optimal state space observer is derived. Furthermore, a feeling system is presented. It determines the requested steering torque that the driver should feel at the steering wheel. This feeling system allows that the driver can experience an almost freely configurable steering feel. Moreover, a vehicle model with tire models and a driver model are added to the control system. Thus, real driving situations can be simulated. The results of the analysis of these real driving situations are presented in this paper. It is shown that the control approach ensures good dynamic characteristics and good robustness characteristics.

   3. Application of a Detailed Model of a Steering System in Highly Dynamic HiL Tests of EPS Motors

      Markus Hemmersbach, Hermann Briese, Michael Haßenberg, Marcus Irmer, Hermann Henrichfreise

      Abstract

      Hardware-in-the-Loop (HiL) tests are common practice in the development process of “Electric Power Steering – EPS” systems. The HiL tests are carried out on power pack test benches, which emulate the real environment, that an EPS motor is exposed to in a real vehicle.

      This paper describes highly dynamic HiL tests of an EPS motor using the power pack test bench of [1] To precisely emulate the real environment of the EPS motor, the detailed steering model of [2] is used and moreover embedded in a vehicle dynamics model. The resulting HiL system consists of the detailed steering model, the vehicle dynamics model, the power pack test bench, and the corresponding test bench actuator control. The HiL system is used to perform the highly dynamic HiL tests and allows realistic parameter sets for every involved model.

      During the HiL tests, the fishhook and the double lane-change are performed. Both are standardized road tests, that include a severe change of the driving direction of the vehicle and are hence highly dynamic excitations of the EPS system. Consequently, the measurement results of both HiL tests are used to prove the performance of the power pack test bench in highly dynamic HiL tests.

   4. Validating Reliability of Automated Driving Functions on a Steerable VEhicle-in-the-Loop (VEL) Test Bench

      Chenlei Han, Alexander Seiffer, Stefan Orf, Frank Hantschel, Shiqing Li

      Abstract

      Extensive safety assurance for automated driving functions is a prerequisite to allow automated vehicles on the road. However, test drives with failure scenarios must ensure safety of the tests and test personal involved. In this paper, a novel validation environment on a steerable VEhicle-in-the-Loop (VEL) test bench is developed. Previous vehicle test benches usually only offer the possibility to represent load profiles in longitudinal direction. On the VEL test bench, the aligning torque is also simulated, so that the steering system of vehicles can also be loaded correctly, and simulated vehicle behaviors are more realistic. In addition, an environment simulation module provides sensor signals like Lidar and Camera to the vehicle control unit. This allows the testing of high-level algorithms like trajectory planning or track control on the test bench. One scenario with degraded vehicle steering motor has been carried out in this validation environment to demonstrate its application.

3. Software

   1. Frontmatter

   2. Improved Scalability of Vehicle Diagnostic Software: Advantages of Service-Oriented Architecture

      Lorenz Görne, Hans-Christian Reuss

      Abstract

      The increasing number of functions in modern vehicle leads to an exponential increase in software complexity. The validity and reliability of all components must nevertheless be ensured, making the use of appropriate vehicle diagnostics systems indispensable. The demands on the software of those systems have become dynamic and multifaceted. This paper proposes the approach of service-oriented software architecture as an answer to increased complexity and flexibility of a vehicle diagnostic system.

      In order to offer competitive diagnostic tools, new requirements must be implemented and offered as quickly as possible. Instead of a monolithic software package that is fixed when the tester is delivered, the diagnostic system breaks down complex functionality into “services” that are less restrictively interconnected. It is important to have a forward-looking design that defines the interfaces and leaves room for changes later-on.

      Strict modularization made it possible to realize a new type of vehicle diagnostic system that can offer versatile tester functions such as interactive vehicle diagnostics or monitoring and recording of vehicle CAN-bus and other communication and reaction to events. These functions are independent and run in parallel, and can thus be optimally adapted to customer requirements.

   3. Digitalized Development Methodology for the Continuous Vehicle Product Life Cycle

      Markus Christian, Thomas Huber

      Abstract

      The automotive industry is undergoing an unprecedented transformation. From new E/E architectures to central vehicle computers, new developments are emerging to deal with increasing complexity and a growing number of functions. As well as making increasing use of affordable consumer IT technologies, vehicle software is evolving into a living object that receives a continuous stream of updates and even functional enhancements. This is creating a new world of entirely new business models in which conventional development methods are reaching their limits. A vehicle exists both as a physical object in the real world and as a digital model, or “digital twin”, each of which is closely synchronized with the other. Development and operations cycles are increasingly merging in a way that would be impossible without virtualization and modern development approaches such as continuous deployment. Bosch and its subsidiary ETAS are shaping this new world. They offer a Software-in-the-Loop (SiL) suite that links the various elements of virtualization to the required development tools in a modular and flexible manner. Coordinated interactions between the key elements of the SiL framework ensure the quality and usability of the virtual world elements. These include, for example, virtual ECUs that guarantee realistic behavior, a powerful simulation and integration tool, virtual networks, and validation through the monitoring of system behavior in the field. Virtualization at the complete-vehicle level is no longer a vision, but a reality that is already used by OEMs.

4. Erratum zu: 21. Internationales Stuttgarter Symposium

   Michael Bargende, Hans-Christian Reuss, Andreas Wagner

5. Backmatter