Tools for Real-Time Control Systems Co-Design : A Survey

This report presents a survey of current simulation tools in the area of integrated control and real-time systems design. Each tool is presented with a quick overview followed by a more detailed section describing comparative aspects of the tool. These aspects describe the context and purpose of the tool (scenarios, development stages, activities, and qualities/constraints being addressed) and the actual tool technology (tool architecture, inputs, outputs, modeling content, extensibility and availability). The tools presented in the survey are the following; Jitterbug and TrueTime from the Department of Automatic Control at Lund University, Sweden, AIDA and XILO from the Department of Machine Design at the Royal Institute of Technology, Sweden, Ptolemy II from the Department of Electrical Engineering and Computer Sciences at Berkeley, California, RTSIM from the RETIS Laboratory, Pisa, Italy, and Syndex and Orccad from INRIA, France. The survey also briefly describes some existing commercial tools related to the area of real-time control systems

Modelling of distributed real-time control systems : an approach for design and early analysis

NR 2014080

Response time analysis for implementation of distributed control systems

Methods for performing response time analysis of real-timesystems are important, not only for their use in traditionalschedulability testing, but also for deriving bounds on outputtiming variations in control applications. Automatic controlsystems are inherently sensitive to variations in periodicityand end-to-end delays. Therefore, real-time performance needsto be considered during control design. For this purpose, anyreal-time analysis of a potential control implementation shouldproduce results that can easily be used to examine how theimplementation affects control performance. To find the maximumresponse time variation for a task, bounds on both minimum andmaximum response times are needed. A tight bound on thismaximum variation is useful in the analysis of controlperformance and can also be used to improve the results of someiterative response time analysis methods. In this thesis, threemethods for response time analysis are developed. While earlier research has focused on bounding maximumresponse times, one of the analysis methods in this thesisallows a computation of the minimum response times ofindependent fixed priority scheduled tasks. The analysis findsthe largest lower bound of response times for such tasks, whichleads to a tighter bound on the response time variations. Asecond analysis method allows exact computation of maximumresponse times for tasks whose arrival times are related byoffsets. The method is a complement to schedule simulationbased analysis, which it outperforms for systems with tasksthat may experience release jitter. A common design principle for distributed real-time systemsis to let the completion of one task trigger the start of oneor more successors. A third method supporting the analysis oftasks in such systems is described. The method extends andimproves earlier methods as it allows a generalized systemmodel and also results in tighter bounds than the originalmethods. This method has been implemented as part of a toolsetthat enables an integrated approach to the design and analysisof control systems and their implementation as distributedreal-time systems. As part of the thesis, models for describingdistributed control systems have been developed. The toolset,which is based on these models, uses the derived response timebounds in a control system performance analysis based onsimulation. The use of the toolset is exemplified in a smallcase study. Keywords:real-time systems, scheduling, response time,fixed priority, control, jitter, offset, schedulabilityanalysisNR 2014080

Introducing structured information handling in automotive EE development

One way for the automotive industry to cope with the demand of a more structured information handling is to adjust model-based development (MBD) to multidisciplinary needs. Many of the issues faced in this transition are as much organizational and managerial as they are technical. In a case study carried out at a global automotive manufacturer a project to improve the electrical and electronics (EE) development has been followed and analyzed. The project originated from different needs identified by management in their ongoing work effort towards MBD as well as by developers who experienced that tools did not support their work situation. This paper describes how the introduction of a new tool support was made in a project carried out within EE development, further it reports on benefits achieved by using the tool. Both the effect on the work of affected EE developers and the expansion of a new information model are discussed, leaving important implications for management. Success keys for putting new support tools into practice are identified here and include; a bottom-up approach, user involvement from the beginning, focus on the individual needs and adaptation to current work practice. Further, management support and adequate resources are essential for extracting long-term benefits.QC 2010073

Tools for Real-Time Control Systems Co-Design

A survey of four co-design tools for joint analysis, simulation, and design of computer-based control systems developed within the Swedish ARTES programme is presented. The tools allow simultaneous treatment of the control aspects and the computing and communication aspects of the control problems. The tools are Jitterbug and TrueTime developed at the Department of Automatic Control LTH, Lund University, and Aida and Xilo developed at the Division of Mechatronics, Department of Machine Elements, KTH