Project Partner Login
Home Mailen Drucken

TIMMO - MASTERING IN-VEHICLE TIMING CONSTRAINTS

European vehicle manufacturers are today presented with big challenges and opportunities. Past growth in sales has been achieved to a large extent by innovations in comfort, with functions like automatic climate control and navigation; safety, such as, for example, vehicle stability control, multiple air-bag systems, and seat-belt control; and environmental protection, including direct fuel injection and catalytic converter control.

These innovations have been made possible by the use of embedded electronics. Today, a car has several tens of computers, communicating through data buses in a complex, distributed, in-vehicle electronic architecture. Future functions will be even more complex, distributed, interconnected and necessarily interdependent. Their correct behaviour will not simply be a matter of functional correctness that is, making sure that the results of the computations are correct, but they will depend on timing and reliability constraints.

Building such systems in an efficient, predictable and reliable way in spite of the increased complexity of functions and architectures and managing the supply chain in a way that allows predictable integration of software components and platforms is the future major challenge of the automotive industrial sector.

CHALLENGES

Many systems today are time-critical or at least time-dependent. The effects of improper timing range from a loss of comfort to life-threatening situations. Vehicle stability control, involving differential braking of individual wheels is an example of a function in which safety depends on the timely delivery of the braking commands. Precise timing and prioritisation of functions are essential for both safety and comfort, as shown below.


Today, timing is mostly taken into consideration late in the development process, during the implementation and integration phase. Timing behaviour is verified by means of measurements at testing time, rather than through formal and systematic analysis. The likely consequences are long and costly design iterations whenever problems are detected. For this reason, a considerable number of innovative functionalities cannot be implemented in a cost-effective manner, and may therefore not be realised. A predictable development process able to handle timing in all phases and capable of verifying and validating the timing behaviour of a real-time system early in the process is a key factor in bringing new innovative features to market and in handling their implementation complexity.

APPROACH

The European research project TIMMO (TIMing MOdel) is after a breakthrough in the area of automotive system timing management using a common, standardised approach for handling all timing-related information during the development process. The complexity—and the cost—of the development cycle is reduced significantly, while reliability is improved. TIMMO is about developing a Timing Augmented Description Language (TADL) and an accompanying methodology that provide

a formal and standardised specification, analysis and verification of timing constraints across all development phases, avoiding over- or under-dimensioned systems and unnecessary iterations in the development process;
a formal and standardised specification, analysis and verification of timing constraints at all levels of abstraction enabling, e.g., timing requirements to be traced across all abstraction levels;
an improved and predictable development cycle enabling a common, standardised infrastructure for handling timing to shorten the development cycle and increase its predictability.,

These are fundamental prerequisites to avoid costly delays in vehicle start-of-production dates and, in turn, to assure confidence in the dependability and quality of a given solution.

RESULTS

TIMMO will have three major results: A formal language for modelling timing aspects, an accompanying methodology that describes how to apply the language in the development process, and a set of case studies serving as example applications and as validators for the language and methodology.

BENEFITS

In developing the timing concepts, industrial and academic partners of the TIMMO project have drawn on their extensive experience with automotive systems. TIMMO concepts are indeed specific to the automotive domain, complementing the automotive standards AUTOSAR and EAST-ADL. The developed language and methodology leverage state-of-the-art results from academic research without sacrificing applicability to practical systems. The main beneficiaries of the TIMMO results are the vehicle manufactures and their suppliers that can use the new language and methodology for a well-defined exchange of timing information in automotive embedded-system development.