IEEE Transactions on Industrial Informatics

1) A Systematic Test for Embedded Automotive Communication Systems
Horauer, Martin; Armengaud, Eric; Steininger, Andreas

Abstract: The introduction of computer-controlled intelligent safety and comfort features has turned cars into highly complex distributed computing systems. In such a system the proper operation of the communication backbone as well as the proper interaction of components from different vendors must be ensured for all configurations and operating conditions. This system-level test goes far beyond the (isolated) test of single components and represents a substantial problem, that seems to be still largely unsolved, although its solution is crucial for maintaining the consumers' trust in modern automotive electronics. In this paper we present an approach that facilitates a systematic test of distributed systems based on FlexRay, the protocol that is envisioned as the communication backbone for future automotive systems. The cornerstones of our approach are a vertical decomposition of the system into layers and mechanisms, and a versatile strategy for monitoring and stimulation under various conditions. Our concept covers the whole range from an early debugging with full access to the system, over non-intrusive on-line testing during interoperability tests, to maintenance testing that is restricted to a remote access only. For all involved issues we give detailed discussions of requirements and our proposed solutions. Selected use cases are presented to demonstrate the usefulness of our approach.

2) Hardware/Software Design Considerations for Automotive Embedded Systems
Salewski, Falk; Kowalewski, Stefan

Abstract: An increasing number of safety-critical functions is taken over by embedded systems in today's automobiles. While standard microcontrollers are the dominant hardware platform in these systems, the decreasing costs of new devices as FPGAs makes it interesting to consider them for automotive applications. In this article, a comparison of microcontrollers and FPGAs with respect to safety and reliability properties is presented. For this comparison, hardware fault handling was considered as well as software fault handling. Own empirical evaluations in the area of software fault handling identified advantages of FPGAs with respect to the encapsulation of real-time functions. On the other hand several dependent failures where detected on versions developed independently on micrcontrollers and FPGAs.

3) The One-Shot Task Model for Robust Real-Time Embedded Control Systems
Marti, Pau; Lozoya, Camilo; Velasco, Manel

Abstract: Embedded control systems are often implemented in small micro-processors enabled with real-time technology. In this context, control laws are often designed according to discrete-time control systems theory and implemented as hard real-time periodic tasks. Standard discrete-time control theory mandates to periodically sample (input) and actuate (output). Depending on how input/output (I/O) operations are performed within the hard real-time periodic task, different control task models can be distinguished. However, existing task models present important drawbacks. They generate task executions prone to violate the periodic control demands, a problem known as sampling and latency jitter. Or they impose synchronized I/O operations at each task job execution that produce a constant but artificially long I/O latency. In this paper, the one-shot task model for implementing control systems in embedded multi-tasking hard real-time platforms is presented. The novel control task model is built upon control theoretical results that indicate that standard control laws can be implemented considering only periodic actuation. Taking advantage of this property, the one-shot task model is shown to remove endemic problems for real-time control systems such as sampling and latency jitters. In addition, it can minimize the harmful effects that long I/O latencies have on control performance. Extensive simulations and real experiments show the feasibility and effectiveness of the novel task model, compared to previous real-time and/or control based solutions.

4) Implementation of H-infinity control algorithms for sensor-constrained mechatronic systems using low-cost microcontrollers
Bautista-Quintero, Ricardo; Pont, Michael

Abstract: This paper introduces a novel method which is intended to assist in the design and implementation of optimal H-infinity (H∞) algorithms in low-cost mechatronic applications. The particular problem considered is position control in a situation where there are both sensor-related uncertainties (caused by low–resolution sensors) and limited computational resources. The first part of the method presented in this paper describes how to design the H∞ algorithm based on dynamic features of the sensor. The second part of the method involves finding a suitable numerical controller representation in order to reduce memory and CPU load. Evaluation of the method is based on empirical studies using three industrial sensors employed in a sub-acted robot. Results for a classic proportional integral derivative (PID) controller are included, in order to provide comparisons with the H∞ approach.

5) Stability Analysis and Practical Design Procedure of Time Delayed Control Systems with Communication Disturbance Observer
Natori, Kenji; Oboe, Roberto; Ohnishi, Kouhei

Abstract: In a research field of network-based control systems (NBCSs), time delay problem is one of the most significant issues. A novel time delay compensation method based on the concept of network disturbance (ND) and communication disturbance observer (CDOB) has been proposed. The compensation method has the same effectiveness as that of Smith predictor. In addition, since the method is simple and does not need time delay model or time delay measurement, it can be easily implemented to various applications. However, the design method has not been concerned so far. This paper therefore presents stability analysis and study a practical design procedure of the time delayed control systems with CDOB. Firstly, the concept of ND is introduced and the validity of the compensation method is described. Then an analysis about the effects of parameters in control systems on stability is conducted. The effects of parameters on stability come out. Then we study a practical design procedure of the time delayed control systems. The validity of the design procedure is verified by experimental results. In experiment section, we also discuss the performance in the case of time-varying delay. Finally a comparative study of the method to Smith predictor is presented.

6) Robust and Efficient Rule Extraction through Data Summarization and its Application in Welding Fault Diagnosis
Huang, Samuel; Gong, Rongsheng; Chen, Tieming

Abstract: Abstract--This paper presents a robust and efficient method to discover knowledge for classification problems through data summarization. It discretizes continues features and then summarizes the data using a contingency table. Inconsistency rate for different subsets of features can then be easily calculated from the contingency table. Sequential search is then used to find the best feature subset. After the number of features is reduced to a certain extent, easy-to-understand knowledge can be intuitively and easily derived from data summary. Another desirable feature of the proposed method is its capability to learn incrementally; namely, knowledge can be updated quickly whenever new data is obtained. Moreover, the proposed method is capable of handling missing values when used for prediction. The practical usefulness of this method in manufacturing is demonstrated through an application on welding fault diagnosis.

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IEEE Industrial Electronics Society

IEEE Transactions on Industrial Informatics

Volume 4, Number 3, August 2008

Editorial

Regular Issue Papers