Nils Ballmann

Bio: Nils Ballmann is an academic researcher from University of Erlangen-Nuremberg. The author has contributed to research in topics: Code generation & Executable. The author has an hindex of 1, co-authored 1 publications receiving 14 citations.

Bridging algorithm and ESL design: Matlab/Simulink model transformation and validation

Abstract: Matlab/Simulink is today's de-facto standard for model-based design in domains such as control engineering and signal processing. Particular strengths of Simulink are rapid design and algorithm exploration. Moreover, commercial tools are available to generate embedded C or HDL code directly from a Simulink model. On the other hand, Simulink models are purely functional models and, hence, designers cannot seamlessly consider the architecture that a Simulink model is later implemented on. In particular, it is not possible to explore the different architectural alternatives and investigate the arising interactions and side-effects directly within Simulink. To benefit from Matlab/Simulink's algorithm exploration capabilities and overcome the outlined drawbacks, this work introduces a model transformation framework that converts a Simulink model to an executable specification, written in an actor-oriented modeling language. This specification then serves as the input of well-established Electronic System Level (ESL) design flows that, e. g., enables Design Space Exploration (DSE) and automatic code generation for both hardware and software. We also present a validation technique that considers the functional correctness by comparing the original Simulink model with the generated specification in a co-simulation environment. The co-simulation can also be used to evaluate the performance of implementation candidates during DSE. As case study, we present and investigate a torque vectoring application from an electric automotive vehicle.

Automatic Conversion of Simulink Models to SysteMoC Actor Networks

Abstract: Simulink has gained a lot of acceptance due to its intuitive through block-based algorithm design, simulation, and rapid prototyping capabilities for signal processing as well as control applications However, automatic code generation for heterogeneous architectures is currently not supported by Simulink In the literature, there exist automatic translation toolchains for generation of C or C++ code from Simulink models, which then are used for implementation or validation purposes But few of them approach the generation of models that can be used in well-established Electronic System Level (ESL) design methodologies and tools In order to address this issue, we present a methodology to extract an executable specification based on Data Flow Graphs (DFGs) from a given Simulink model Such a specification can then be used by ESL tools to perform a Design Space Exploration (DSE) and generate code for hardware/software partitions directly from the ESL model In a case study from signal processing, we validate the equivalence of the results of the simulation in Simulink and the results obtained by simulation of the DFG fully automatically generated from the Simulink model in the SystemC-based actor language SysteMoC

Automatic SDF-based Code Generation from Simulink Models for Embedded Software Development.

Abstract: Matlab/Simulink is a wide-spread tool for model-based design of embedded systems. Supporting hierarchy, domain specific building blocks, functional simulation and automatic code-generation, makes it well-suited for the design of control and signal processing systems. In this work, we propose an automated translation methodology for a subset of Simulink models to Synchronous dataflow Graphs (SDFGs) including the automatic code-generation of SDF-compatible embedded code. A translation of Simulink models to SDFGs, is very suitable due to Simulink actor-oriented modeling nature, allowing the application of several optimization techniques from the SDFG domain. Because of their well-defined semantics, SDFGs can be analyzed at compiling phase to obtain deadlock-free and memory-efficient schedules. In addition, several real-time analysis methods exist which allow throughput-optimal mappings of SDFGs to Multiprocessor on Chip (MPSoC) while guaranteeing upper-bounded latencies. The correctness of our translation is justified by integrating the SDF generated code as a software-in-the-loop (SIL) and comparing its results with the results of the model-in-the-loop (MIL) simulation of reference Simulink models. The translation is demonstrated with the help of two case studies: a Transmission Controller Unit (TCU) and an Automatic Climate Control.

Co‑simulation Improvement for Uncertain Flexible Robot Arm

Abstract: Flexible robot arm driven by Brushless DC Motor (BDCM) under uncertainties represents one of the most complex and heterogeneous system. Indeed, the verification phase becomes a great challenge for designers. Avoid and predict risks accurately at earlier stage represents the main purpose of the Computer-Aided Design (CAD) field. This paper treats the case of robotics system for tracking trajectory problem and attempts to improve the verification phase by identifying the most suitable co-simulation technique. For the system analyzed in this paper, the flexible robot arm driven by Brushless DC actuator is verified using the Model In the Loop (MIL) technique, the Software In the Loop (SIL) technique and CODIS + technique. Each one verifies the system according to a particular abstraction level. The performance of each technique is determined by measuring the accuracy and time simulation. Experimental results have revealed that CODIS+ is the most adequate technique for flexible robot arm, outperforming MIL and SIL by 4–5 times.

Rapid heterogeneous prototyping from Simulink

Abstract: Designing embedded high-performance systems is challenging due to complex algorithms, real-time operations and conflicting goals (e.g. power v.s. performance). Heterogeneous platforms that combine processors and custom hardware accelerators are a promising approach. However, manually designing HW/SW systems is prohibitively expensive due to the immense manual effort. This paper introduces SimSH: Simulink Sw/Hw CoDesign Framework, which provides an automatic path from an algorithm captured in Simulink to a heterogeneous implementation. Given an allocation and a mapping decision, the SimSH automatically synthesizes the Simulink model onto the heterogeneous target with reconstruction of the synchronization and communication between processing elements. In the process, the SimSH detects an underutilized bus and optimizes communication by packing/unpacking. Synthesizing a heterogeneous implementation from Simulink allows the developer to focus on the algorithm design with rapid validation and test on a heterogeneous platform. We demonstrate synthesis benefits using a Sobel Edge Detection algorithm and target a heterogeneous architecture of Blackfin processor and Spar-tan3E FPGA. The synthesized solution is 2.68x faster (and energy efficient) over pure SW execution.

Model Transformation: Concept, Current Trends and Challenges

Abstract: Driven Engineering (MDE) is gaining popularity as an alternative to the code-centric software development approach. Model Transformation (MT) is one of the main components of MDE. MT can be visualized as a program with models as inputs. Model evaluation and processing is automated by a Model Transformation tool. In this paper, we walk through the terminologies involved in MT and elaborate the benefits of MT with practical usage scenarios. The paper highlights the most recent challenges faced in the process to make model transformation more sophisticated. The intent of the paper is to portray a complete picture of model transformation in a way to relate the practical implementations with respect to the theoretical aspects of MT. The paper concludes by putting lights on some of the current trends in the field and the areas in model transformation where significant contribution is the needed.