Vishnu Kumar Kaliappan

Designing and Verifying Communication Protocols Using Model Driven Architecture and Spin Model Checker

The need of communication protocols in todaypsilas environment increases as much as the network explores. Many new kinds of protocols, e.g. for information sharing, security, etc., are being developed day-to-day which often leads to rapid, premature developments. Many protocols have not scaled to satisfy important properties like deadlock and livelock freedom, since MDA focuses on the rapid development rather than on the quality of the developed models. In order to fix the above, we introduce a 2-Phase strategy based on the UML state machine and sequence diagram to satisfy the properties of communication protocols. We convert these models into PROMELA code for execution on the SPIN model checker. The results are compared with the developed UML models.

Fault tolerant controller design for component faults of a small scale unmanned aerial vehicle

In this paper additive fault detection and isolation method coupled with fault tolerant control architecture are developed in order to deal with component faults for a rotorcraft based unmanned aerial vehicle (RUAV). The failure considered is malfunction with internal components of the helicopter which occurs during the maneuvers: rotor angular rate variations, etc. These faults lead from trivial to catastrophic damage of the system. The proposed fault detection and reconfiguration control is based on a parameter estimation approach which drives a reconfigurable control system (RCS) build with the Pseudo-inverse method. The complete setup is implemented under Hardware-in-the-loop-simulation (HILS). The PC104 board with QNX RTOS platform is used for simulation. Simulation results illustrate the efficiency and effectiveness of the proposed approach.

Behavior-based decentralized approach for cooperative control of a multiple small scale unmanned helicopter

RUAV (Rotorcraft based Unmanned Aerial Vehicle) have been exploited in various fields such as surveillance, reconnaissance and search. Most of the study in this area is focused on single RUAV; however using multiple unmanned vehicles is big advantage to accomplish the mission in a short time and effective way. Moreover little amount of research has been undertaken in the development of multiple RUAV control systems. This paper proposes a behavior-based decentralized approach that allows an RUAV to carry out its own mission of flying to a specified region while the distances between RUAVs are maintained constantly to avoid collision. The main goal of the proposed controller is to make the RUAV cooperate among each other to achieve the defined task. In this research Reynolds flocking model based behavior approach has been utilized. Along with this the testing environment for multiple RUAV is developed to validate proposed control algorithm. Complete setup is implemented and run under QNX RTOS, based on PC104 embedded board. The multiple RUAV is tested and evaluated using HILS (Hardware-In-the-Loop Simulation). To validate the proposed approach, simulation is performed to achieve the waypoint with multiple RUAVs.

Hardware-In-the-Loop Simulation Platform for the Design, Testing and Validation of Autonomous Control System for Unmanned Underwater Vehicle

Significant advances in various relevant science and engineering disciplines have propelled the development of more advanced, yet reliable and practical underwater vehicles. A great array of vehicle types and applications has been produced along with a wide range of innovative approaches for enhancing the performance of unmanned underwater vehicle (UUV). These recent advances enable the extension of UUVs’ flight envelope comparable to that of manned vehicles. For undertaking longer missions, therefore more advanced control and navigation will be required to maintain an accurate position over larger operational envelope particularly when a close proximity to obstacles (such as manned vehicles, pipelines, underwater structures) is involved. In this case, a sufficiently good model is prerequisite of control system design. System evaluation and testing of unmanned underwater vehicles in certain environment can be tedious, time consuming and expensive. This paper, focused on developing dynamic model of UUV for the purpose of guidance and control. Along with this a HILS (Hardware-In-the-Loop Simulation) based novel framework for rapid construction of testing scenarios with embedded systems has been investigated. The modeling approach is implemented for the AUV Squid, an autonomous underwater vehicle that was designed, developed and tested by research team at Center for Unmanned System Studies at Institut Teknologi Bandung.

Deriving the behavioral properties from UML designs as LTL for model checking

Design models help the system development to analyze and visualize its working scenario as a blueprint or a prototype. A successful or error free design leads to an efficient implementation. Thus ensuring the design correctness is a crucial factor in a complex system development like communication protocols. They are reactive in nature and the general verification like correctness evaluation will not yield an effective design because they change their behaviors from time-to-time. One of the way to overcome this problem is to verify their functional behaviors based on the time interval i.e., temporal ordering. To achieve this, an approach called verification property generator is proposed in this paper. The possible functional behaviors are captured in linear temporal logic for the given unified modeling language diagram based on the assumption rules. Here, the safety and liveness properties are defined independently that reduces the verification overhead. The approach is presented in general and hence the properties can be evaluated under any model checking environment.

Reconfigurable intelligent control architecture of a small-scale unmanned helicopter

Over the past decades, substantial research has been undertaken in the design of intelligent architecture for the rotorcraft-based unmanned aerial vehicles (RUAV). Designing intelligent architecture is a challenging problem because future RUAVs are utterly autonomous and their performance is comparable with that of manned vehicles. This paper deals with the design and development of a layered architectural framework that addresses the issue arising in autonomous intelligent control systems. The architecture consists of two layers. The high-level layer is occupied by planning routines. In this level, the waypoints and mission tasks from the command center are executed. The function of the low-level layer is to stabilize the flight and follow the commanded trajectory from the upper layer. These layers integrate the following functionalities: (1) waypoint navigation and control, which includes auto-landing; (2) obstacle detection and avoidance; (3) fault detection and identification; and (4) system reconfiguration in two levels (high-level and low-level controllers). The resulting layered architecture is discussed in detail. Moreover, the novel fault detection and identification method is developed to address multiplicative and additive faults. A testing environment for RUAV is developed to validate this architecture. Complete setup is carried out using an embedded board run under a real-time operating system. The algorithms are tested and evaluated using hardware-in-the-loop simulation (HILS). The simulation result proves that the proposed architecture demonstrates the desired efficiency and reliability.

Linear velocity based predictive control design and experiment for pursuit-evasion of a multiple small scale unmanned helicopter

In this paper, linear velocity based predictive control of unmanned aerial vehicle (UAV) for pursuit-evasion scenario is presented. The issues of multi-UAV control system are resolved with distributed control structure, to control and coordination multiple pursuers. The group operation of UAVs is realized by decentralized linear velocity predictor control, which interacts with other UAV through communication system. In this research Reynolds biologically inspired steering behavior model has been utilized. The proposed algorithm is implemented on JR Voyager G-260 small scale helicopter controller and tested with HILS (Hardware-In-the-Loop Simulation). With the multiple UAVs the variety of test from waypoint to pursuit-evasion is taken to demonstrate the effectiveness of our approach.

An approach to verify component-based designs

Ensuring design correctness is an important task in the software development and in particular component-based protocol development. We developed a component-oriented design approach for the design of communication protocols and distributed systems. The approach aims at the reuse of components represented by Unified Modeling Language (UML) diagrams. In this paper we propose a verification approach to verify our component-based protocol designs by combing trace equivalence and model checking. Foremost, the internal and external component behaviors are verified independently regarding their formal correctness. Next, the correctness and consistency of compositions are verified. This is achieved by generating the component adaptation path as traces during the composition. The requirements, i.e., safety and liveness properties, are formulated using linear temporal logic formulae. We apply the Spin tool as our model checking mechanism. For this, we present a method for automatically transforming the protocol design components into PROMELA.

A Structured Template for an Effcient Dependable System Design Using Model Driven Architecture and Spin Tool

Dependability is one of the critical system level issues in protocol design and it is not efficiently solved today. The main factor in this issue is the lack of design/modeling specifications with proper semantics. Most of the design specifications capture either hardware or software entities. In order to solve this problem we propose an architecture template for designing dependable systems. Our approach uses the model driven architecture as the base and it is redesigned by addressing the properties of dependability. More preciously, the verification and validation tools are incorporated in the design phase, which enables the development to be stable at any cost of time. In order to test the efficiency of the template, the example data transfer protocol (protocol used for data transfer over an unreliable media) is analyzed and implemented with the template. The spin plug-in tool is used in the proposed template to verify the design level test results. Our test results impress the designer to verify the expected results with the system design and to identify the errors which are unnoticed during the design phase.