Arun Chakrapani Rao

A Critical Analysis of Model-Based Formal Verification Efforts within the Automotive Industry

There are a number of software-controlled features in todays automotive vehicles to meet the increasing number of requirements for comfort, safety, infotainment and reduced emissions. To meet the growing demands from such features, the software content is not only increasing rapidly, but also becoming increasingly distributed within the Electronic Control Units (ECUs), leading to the possibility of unwanted interactions and consequent loss of reliability. Therefore, the automotive software-based features have to be designed and verified using sophisticated tools and techniques.Formal methods-based techniques and tools have been used on various industrial designs over the past 6 years by one of the authors in development and applied research projects, collaborating with a number of automotive companies. The challenges faced in large projects are discussed in this context. A large number of industrial users have recounted their own experiences in user conferences and workshops, which will be summarized. The results of a short survey of real users will also be discussed in this context.

Model based validation techniques for complex control systems

The complexity of developing todays hybrid powertrain control systems is increasingly being dealt with by the use of model based design methods. This introduces new opportunities, and challenges, in identifying and using advanced validation techniques to best utilise model based design artifacts. This paper discusses some of the advanced validation techniques used within the premium automotive research and development (PARD) programme and identifies further on-going work within a new project called evolutionary validation of complex systems (EvoCS).

Applying Design Verification Tools in Automotive Software V&V

Design verification technology promises comprehensive analysis of design models against the specified properties, thereby overcoming the limitations of traditional simulation-based and testing-based approaches. It helps in detecting design bugs early, thereby reducing the software development cycle time and cost. In this paper, we present our experiences with three state-of-the-art design verification tools - Reactis Validator, Simulink Design Verifier and Embedded Validator - for Simulink/Stateflow models. We also identify some challenges in employing them in an industrial production environment. We also suggest some automation steps to ease the design verification effort.

Systems modelling of a driver information system - automotive industry case study

This paper describes work done at the IARC, in collaboration with an automotive original equipment manufacturer (OEM) and suppliers, in the project systems modelling language (SysML) for automotive software development and integration. The OEM is interested in how a SysML model could supplement or even replace paper specifications whereas the suppliers are more interested in finding how the resulting SysML model could be used for software development. The project focuses on practical aspects so that deployment of the language and related technology is possible smoothly. The case study involves a driver information system for a premium vehicle. Our industry partner supplied the requirements and specification documents. The progress to-date including the challenges faced, results so far and the plan for further work are detailed

Formal Requirements Analysis Techniques for Software-Intensive Automotive Electronic Control Systems

The ever increasing number and complexity of software-controlled features in todays automotive vehicles mandate the use of numerous techniques and tools for ensuring the absence of any kind of defects in them. In this connection, one of the key areas of applied research today involves the identification, development and use of various analyses on Feature Requirements so that any defects can be caught early in the system development lifecycle. In this paper, the following aspects will be covered: 1) an overview of various analyses available within current commercial requirements tools, 2) a discussion on what additional analyses at the requirements level would be desirable to help various stakeholders in the system development lifecycle, 3) an overview of what GM R&D has been developing/have developed to-date in order to identify or help identify various kinds of defects and thereby improve the requirements, 4) some key results and experiences in utilizing such analyses in one/more pilot applications and 5) a discussion of how the benefits of both current and new techniques and tools can be made use of in the development of new software -based automotive electronic control systems.

PICASSOS – Practical applications of automated formal methods to safety related automotive systems

PICASSOS was a UK government funded program to improve the ability of automotive supply chains to develop demonstrably safe highly complex software-intensive systems cost effectively. This was executed by a consortium of three universities and five companies including an automotive OEM and suppliers. Three major elements of the PICASSOS project were: use of automated model based verification technology utilising formal methods; application of this technology in the context of ISO 26262; and evaluation to measure the impact of this approach to inform key management decisions on the costs, benefits and risks of applying this technology on live projects. The project spanned system level design and software development. This was achieved by using a unified model based process incorporating SysML at the system level and using Simulink and Stateflow auto-coded into C at the software level. An ISO 26262 compliant development process based on those already used by the commercial partners was used as a baseline, and a modified process using formal methods was developed. Tools that are commercially available were used wherever possible, and technology demonstrators were generated within the program. One of the program partners is enhancing these tools to make them suitable for commercial sale. A number of trials were undertaken comparing these two processes on Electric Vehicle based systems. The paper includes the results of one of the trials, showing that the formal methods based approach found errors that were missed by the standard process without significantly increasing the development time.

Advances in addressing challenges in complex control systems design

This paper gives an account of various challenges that are faced in the design and development of complex control systems and software, within the automotive and aerospace domains, in particular, which are highly relevant to the incorporation of active mechanisms for dynamic systems. It also analyses what new recent advances are helping some of these being overcome in the research and engineering environments.