Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 6: IPAD system development and operation

The strategy of the IPAD implementation plan presented, proposes a three phase development of the IPAD system and technical modules, and the transfer of this capability from the development environment to the aerospace vehicle design environment. The system and technical module capabilities for each phase of development are described. The system and technical module programming languages are recommended as well as the initial host computer system hardware and operating system. The cost of developing the IPAD technology is estimated. A schedule displaying the flowtime required for each development task is given. A PERT chart gives the developmental relationships of each of the tasks and an estimate of the operational cost of the IPAD system is offered

Automatic translation from FBD-PLC-programs to NuSMV for model checking safety-critical control systems

Programmable logic controllers (PLCs) are digital control systems, commonly used in industrial automation and safety-critical applications. Control systems used in safety-critical areas must undergo an extensive and thorough certification and verification process. In safety-critical applications, the PLC programming standard IEC 61131-3 is widely accepted in industry. PLC programmers who develop control systems for safety-critical systems are often required to verify the logic of PLCs by using formal methods such as model checking. Translating manually from a PLC program to the input language of a model checker takes times and is often error-prone. We develop a compiler to automatically translate PLC programs in the function block diagram (FBD) language, one of five industry standard PLC programming notations, to the input language of the model checker NuSMV. We have evaluated correctness, robustness, and performance of the PLC-NuSMV compiler using a case study. Evaluation results show that the compiler can translate the PLC programs correctly. The compiler can also identify several input errors and can scale to relative large PLC programs

SURVEILLANCE SYSTEM FOR IDGHwAY MONITORING

Surveillance System for Highway Monitoring is an intelligent system which can detect congestion in the highways and automatically alert the highway users. This project aims to design and build a system which is able to monitor traffic congestion on highways and automatically alert the users. This will help the road users in planning their journey by giving them the current situation of the highways. The system consists of mainly the Programmable Logic Controller (PLCs ), sensors and alert devices. This system functions to give awareness to highway users and also help reduce highway congestion by monitoring the highways. The infrared sensors will detect the vehicles and the PLC will be programmed to count the frequency of vehicles that passes the sensor. If the frequency exceeds a certain limit, it will firstly warn the highway users at the entrance of the highway and along the highway so that they may use other road alternatives. If the frequency exceeds the second limit, then the system will warn the highway users that the high is jam and recommends another route to be taken

Subsea Production Control System Modelling

Subsea control systems in subsea production system (SPS) play a vital role in the safe and productive operation of any oil or gas field. These systems operate in extreme environments, thus making the installation and commissioning the system risky and costly. For a new developer, a better understanding on how the system works is needed to ensure that the system will meet all design specifications and reduce the risk and costs associated with installation and commissioning. Leading oil and gas companies turned to identify the critical responses and behaviors expected from the designed system through simulation software, where the whole subsea control systems from the Hydraulic Power Unit to the Subsea Control Module can be modeled. In this report, a case study from Cadlao field off the shores of Philippines is used to perform a simulation study on. The field uses a direct hydraulic control system, which from the literature review done, is considered to be the building stone of all other control systems available. The simulation was made by a new simulation tool called Agito ITI SimulationX. The simulation results are then compared with those from the actual field outputs recorded from the Cadlao field. The results of the simulation and the discussion showcases the response of the gate valve actuator and its relation with umbilical hose and Directional Control Valve. Comparison between the experimented results and the simulated results were made to stand upon relativeness of the simulated results

Refinement-based verification of sequential implementations of Stateflow charts

Simulink/Stateflow charts are widely used in industry for the specification of control systems, which are often safety-critical. This suggests a need for a formal treatment of such models. In previous work, we have proposed a technique for automatic generation of formal models of Stateflow blocks to support refinement-based reasoning. In this article, we present a refinement strategy that supports the verification of automatically generated sequential C implementations of Stateflow charts. In particular, we discuss how this strategy can be specialised to take advantage of architectural features in order to allow a higher level of automation.Comment: In Proceedings Refine 2011, arXiv:1106.348