Ana Maria Ambrosio

National Institute for Space Research, Brazil | inpe · Curso de Pós-Graduação em Engenharia e Tecnologia Espaciais (ETE)

Satellite’s operation is an intricate task because it involves a complex system with many critical variables to be observed and analysed. Tools to support operation are crucial to ensure system health monitoring and avoid human error in the operation’s conduct. In Brazil, the National Institute for Space Research (INPE) has more recently developed...

During the satellite’s operations, simulation tools perform an important role in ensuring the space mission success. In this sense, the models implemented in the context of an operational satellite simulator that enables analysis of health status and maintenance during operations shall reflect the current satellite behavior with high fidelity. More...

Nanosatellite, including the CubeSat platform, is a low-cost and fast alternative for human resources training and technological validation in the space area. Over the years and with increasing numbers of nanosatellite missions, this alternative has demonstrated satisfactory. Also, it has attracted the attention of the space industry, involving mor...

Tangible user interface brings back physical cognitive artifacts empowered with Internet of Things, and it will be a key instrument in Industry 4.0 to control software. Such artifacts are tangible mental representation of the context of a system being built with software tools. One of the challenges on applying tangible user interface to define an...

Satellite operational simulator is a tool used to support the operation of a satellite. In this paper an Artificial Neural Network (ANN) was used to design models that describe parts of a satellite’s Electrical Power Supply Subsystem. The results are compared with previous research using an identification technique called n4sid and with the real te...

With the purpose of making the use of model based techniques in industrial software development more efficient, this work proposes the combined application of two verification techniques: model checking with UPPAAL and CoFI (Conformance and Fault Injection) model based testing with ConData. This combination is supported by ConTEA, a software tool f...

Operational simulators have a fundamental role in space programs. During a satellite operation, these simulators are essential for validating critical manoeuvres, testing new on-board software versions, and supporting the diagnosis of anomalies. With the purpose of reusing the operational simulators, the Brazilian National Institute for Space Resea...

Operational satellite simulators are mainly used for training operators and validating operational procedures, requiring reasonable level of fidelity in the simulated satellite telemetry. In this paper we propose the use of the subspace identification method to improve a higher level of fidelity of the model representing the CBERS-4 Electrical Powe...

O uso de Modelagem & Simulação contribui para a realização das atividades de Verificação & Validação de sistemas espaciais, ajudando a compreender o sistema e possibilitando análises para redução de riscos e custos. Este artigo apresenta o resultado de uma experiência realizada durante o estágio do Curso de Inverno realizado no INPE em 2015. O está...

Problems in requirements documents are among the root cause of a number of accidents in space missions. A common approach toward the minimization of these problems is to transform the requirements into models that represent the system's behavior. However, this solution requires dealing with issues such as choosing the best modeling formalism, defin...

This article presents the result of an experiment developed during the short internship of the Winter Introductory Course on Space Engineering and Technology at INPE which supported the SIMCBERS simulator modeling and verification. It was implemented a performance model of the Data Collection Subsystem using Simulink. The results that came from thi...

In space systems engineering, the Operational Simulator (OS) is a computational tool that can be used to test and validate the ground control system, to train the flight control operators, and to support the operation of spacecrafts. In order to accomplish these tasks, the OS must produce data of all the spacecraft subsystems in real-time. Among th...

Satellite simulators are developed in the context of a space mission lifecycle to represent the real behavior of a satellite during operation and may be used for different purposes. To attain a particular purpose new functions are added or modified according to the mission phase needs, requiring models re-adaptation in a system evolving concept. Th...

The process of a satellite simulator software verification demands high-efficiency in meeting realistic set of functional requirements. Based on this, the manual verification process becomes impracticable, thereby requiring an automated process. The satellite behavior that is represented here into tables of cause-effect rules requires to assure tha...

This paper aims to describe the structure of a framework for an automated pico and nanosatellite model validation, using commercial tools. It was proposed that the models are as granular as in the verification plans (it is not possible to test internal behaviors from a black box artifact), so, each model represent an element in a unique file and a...

Tests in the space systems development life cycles are necessary to early verify requirements fulfillment, ensuring that the systems developed are correct. Nowadays, the efforts to develop miniaturized satellites and their test suite is increasing. Additionally, it is growing the initiatives is adopting MBSE (Model Based System Engineering) to auto...

Abstract The National Institute for Space Research – INPE (in Portuguese “Instituto Nacional de Pesquisas Espaciais”) is the major research center of the space sector at Brazil. Among the main research and development activities at INPE, is the Space Engineering and Technology ETE (in Portuguese “Engenharia e Tecnologia Espaciais”), which cover...

The software in satellite applications has become increasingly larger, more complex and more integrated, so its verification and validation require exploration of new approaches. In this paper we present a Model-Based Testing (MBT) approach applied to the Communication Module of the ITASAT-1 university satellite. The models are Finite State Machine...

Specifying a resilience benchmark is a difficult task due to the complexity of the benchmark components and the need for standardization. Existing approaches for benchmark specification, including document-based and program-based approaches, are limited in terms of their scope and in the support they provide to the benchmark users. In this short pa...

The role of embedded software in the last space accidents highlights the importance of verification and validation techniques for the development of space embedded software. In this context, this work analyses the contribution of two verification techniques applied to the onboard data handling software of space products. The first technique is mode...

Este relatório compila e analisa os resultados da modelagem de quatro trabalhos experimentais realizados durante a disciplina de Verificação e Validação de Sistemas Espaciais (CSE-207-4), ministrada pela professora Dra. Ana Maria Ambrosio, no terceiro período letivo de 2013, do curso de pósgraduação em Engenharia e Tecnologias Espaciais (PG-ETE)....

Satellite simulators are used to support the tasks of space mission analysis and satellite verification and operation, having high dependability requirements. When used for different missions or different phases of the same mission, robustness and scalability are two particularly important properties. This practical experience report presents the r...

Attitude and Orbit Control System (AOCS) is one subsystem of the Service Module of a satellite which mostly endures faults in space operations. The criticality and complex nature of the subsystem demands an extensive effort in its integration and controller's software testing, mainly for validating the Fault Detection, Identification and Recovery (...

A large gap between the academic studies and the industry effective use of model-based testing approaches is still a reality, despite the academic effort in developing new techniques and tools. CoFI (Conformance and Fault Injection) is a model-based methodology developed to address the testing needs of embedded software in space missions. Beside ot...

Due to its large territory, Brazil relies on space systems to perform a myriad of supporting activities. Space systems design requires strong modeling and simulations techniques for achieving high performance. This article describes the development of a goal-driven user interface (UI) for spacecraft distributed simulations using a service oriented...

This work describes an initiative to a serious game-like user interface used for an operational satellite simulator. The simulator is part of a simulation architecture intended to provide a richer behavior analysis tool set to the real artefact, as a source of possible behaviors scenarios. In order to interact with the underlying behaviour, the use...

Hybrid systems are characterized by a composition of discrete and continuous dynamics. In particular, the system has a continuous evolution and occasional jumps. The jumps are caused either by controllable, uncontrollable external events or by its continuous evolution. Inevitably, this type of system is present in mobility devices such as cars, shi...

Telemetry data is the only source for identifying/predicting anomalies in artificial satellites. Human specialists analyze these data in real time, but its large volume, makes this analysis extremely difficult. In this experience paper we study the hypothesis of using clustering algorithms to help operators and analysts to perform telemetry analysi...

To write a satellite simulator specification for a relatively simple satellite may be simple as the information can be shared among the small group of hardware experts, system engineers and software programmers. However, this becomes extremely difficult as the number of people involved increases. This paper focuses on questions related to how to wr...

This paper presents a field study on real errors found in space software requirements documents. The goal is to understand and characterize the most frequent types of requirement problems in this critical application domain. To classify the software requirement errors analyzed we initially used a well-known existing taxonomy that was later extended...

Poorly written requirements are a common source of software defects. In application areas like space systems, the cost of malfunctioning software can be very high. This way, assessing the quality of software requirements before coding is of utmost importance. This work proposes a systematic procedure for assessing software requirements for space sy...

This paper discusses the practical experience of verifying an On-Board Data Handling (OBDH) software to be used in a future satellite application at INPE using the CoFI testing methodology. This technique is proper for aerospace applications and is based on modeling the system under test as finite state machines. The test cases are automatically ge...

The perspectives of multiple launchings, in the near future, by INPE's satellite program motivated the development of an application using temporal planning techniques based on Artificial Intelligence (AI) concepts. It will be used for automatic generation of flight operation plans to control satellite activities. However, making a critical analysi...

This paper discusses the practical experience of verifying an On-Board Data Handling (OBDH) software to be used in a future satellite application at INPE using the CoFI testing methodology. This technique is proper for aerospace applications and is based on modeling the system under test as finite state machines. The test cases are automatically ge...

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This paper presents a comparative analysis of two verification techniques: (1) formal verification of the system specification and (2) execution of FSM-derived test cases on the delivered product. It uses as a testbench a didactic example of a coffee machine and a work team composed of post-graduation students. The purpose is to analyze the advanta...

This paper presents an Independent Software Verification and Validation process that applies reviews for verification and a systematic testing methodology to guide validation. This process was applied to a pilot project named Quality Software Embedded in Space Missions (QSEE) at INPE and pointed very good results. The main feature of the process is...

Service-orientation is a new paradigm that is emerging for the development of distributed and scalable applications. It is based on object-oriented and component-based paradigms, in which the services (autonomous platform-independent computational elements that can be described, published, discovered and accessed over the Internet using standard pr...

aspect of a specification (FSM model) and also for the data part (EFSM model). The output is an abstract test sequence in an IUT-independent notation. Test cases of the control structure is achieved by applying FSM-based techniques. In this case our aim was to

Software for space applications requires significant testing. This paper presents an evaluation of the CoFI testing methodology as applied to actual space software, where deterministic fault cases derived from state-based models were executed using the software-implemented fault injection technique. Different models were used to represent the behav...

Nowadays, IT outsourcing is an increasing market in the world. This tendency can also be observed in space sector. Particular attention to software acquisition is given by the European Cooperation for Space Standardization (ECSS) providing volumes in software quality assurance and software engineering for space missions in order to make it easier t...

The high cost and the compression of the development timescale of a realistic satellite simulator motivated the definition of a set of functional requirements based on standardized space services, which is presented in this paper. In order to improve as much as possible reusability and consequently decreasing cost in development, the use of standar...

This paper presents the tailoring of ECSS software product assurance requirements aiming at the development of scientific satellite payload embedded software by a Brazilian software supplier. The software item, named SWPDC, developed by DBA Engenharia de Sistemas LTDA within Software Factory context, is part of an ongoing research project, named Qu...

This article presents a set of proposed steps to translate a software service specification from a textual description into a formal notation. This translation is important to reduce ambiguity inherent in textual description and avoid misunderstandings. The referred steps were initially proposed in the context of a testing methodology; however, her...

This paper presents the new architecture of the satellite simulator software for the third China-Brazil Earth Resources Satellite (CBERS-3). This architecture is flexible and scalable to comply with the new challenge imposed of making software reusable to reduce cost. The article discusses previous solutions adopted at INPE since the 90’s. Advantag...

O presente artigo relata as experiências adquiridas pelo INPE e a DBA com a aplicação das normas ECSS no processo de verificação e validação do software embarcado em cargas úteis de satélites científicos. O software piloto SWPCD, objeto da terceirização da Fábrica de Software da DBA pelo INPE, encontra-se em fase de desenvolvimento no escopo do pro...

Comprehensive tests for space applications software are costly but extremely necessary. These software must be reliable and produced within schedule and budget. In a tentative of make the space mission software development for space agencies and industries more cost-effective, the European Committee for Space Standardization (ECSS) has been compili...

PLAVIS project aims at establishing the basis for a platform (an integrated set of tools) to support the VV&T activities, providing an environment that improves the validation and verification process applied to space software systems. This paper introduces an environment, named Plavis/FSM, which integrates the tools Condado, MGASet and Proteum/FSM...

The most critical activity of a V&V process is the test design, as it should be systematic and less dependent of the expert inspiration, mainly for companies developing software whose failures place millions of dollars in risk. Additionally, the trend towards services standardization for the most common space applications motivated us to define a c...

This paper presents an approach for black-box test case derivation from a set of concurrent FSM, in which the product machine is not generated. The approach is based on the concept of independent and communicating transitions. An algorithm to recognize the communicating transitions from the concurrent-FSM-based specification is presented. A set of...

This work presents a customization of the European Cooperation for Space Standardization (ECSS) standards for defining a development process for the ground segment of the FBM project. The FBM project consists of a scientific/technological space mission developed in cooperation between Brazil and France. In this project, the development of the groun...

This paper describes a tool called ConData used as test generation for communication protocols specified as extended finite state machines. The strategy for test generation combines different specification-based test methods: (i) transition testing for the control part of a protocol and (ii) syntax and equivalence partitioning for the data part. Th...

This paper presents our experience in testing an object-oriented software: the Telemetry and Telecommand System (TMTC). The TMTC runs along a distributed architecture comprising microcomputers plus a Data Base server inter-connected via LAN under TCP/IP protocol. This in-house developed software was designed according to the Object Modelling Techni...

This paper describes a tool called ConData used as test generation for communication protocols specified as extended finite state machines. The strategy for test generation combines different specification-based test methods: (i) transition testing for the control part of a protocol and (ii) syntax and equivalence partitioning for the data part. Th...

This paper presents an adaptation of the Hierarchical Approach for Object-Oriented SofMare Testing, defined by Siegel', used in the verification and validation process of the Satellite Control System with the following characteristics: designed according to the Object Modeling Technology (OMT), implemented in C+ +, providing: a window-based user in...

This paper presents the experience of migration of National Space Research Institute (INPE) Satellite Control System from a centralized architecture to a distributed one. The aims of this migration are: to fulfill the requirements of the different space missions planned for the next years; to reduce the costs of hardware maintenance and software de...

This paper presents the architecture and the concepts of the GAN (Antenna Manager Software) designed to execute pre-defined strategies to acquire the Brazilian satellite SCD1 on the horizon as well as to monitor and recover the satellite in any abnormal situation. Its primary objective is to allow ground station operators to track automatically the...

The technological changes has been affecting the development process leading the organizations to modify the conception and the own way of organizing their work [6]. This paper presents the work and the lessons learned during the upgrade of the INPE's Satellite Control Center (SCC) by moving from the old VAX mainframe computer to a network of perso...

This paper describes the ATIFS, a testing toolset which supports the activities of black-box tests for reactive systems, especially communication systems. In ATIFS, two types of testing are carried out: conformance testing and software fault injection. These testing types allow one to answer such questions about the system under test as: "does the...

This paper presents a test process named CoFI (Conformance and Fault Injection), which has being defined as part of the doctorate program. CoFI integrates two existing test approaches: conformance test and fault injection technique. It was conceived for validating the space communication services being standardized by ESA. For the test case specifi...

This paper addresses the problem of automatically generating test cases of the behavior of communication software systems, the protocols, which are usually specified in Extended Finite State Machines. The specification technique Statecharts is considered here for specifying the protocol behavior with the objective of using its descriptive power of...

Safety, availability and reliability -attributes related to dependability -are very important issues in the context of Space Systems and Missions. In this paper we present a software architecture that integrates well-known Business Intelligent tools as Data warehouse, OLAP and Data Mining. We intend to take advantage of the largest amount of histor...

This paper presents a strategy for validation of an automatic satellite flight operation plan operated by INPE. Part of the strategy is based on a validation tool that applies software agent technology aiming to maintain the integrity of the satellite. The strategy is in line with the recommendations of major international spaces agencies for safet...

This paper presents some experiences in adapting the concepts, framework and methodology for protocol testing from the standard IS-9646 to validate space application protocols. In order to assess the space applications the conformance tests defined in IS-9646 are combined with the fault injection technique. This solution comprises a test architectu...

This work presents a new methodology for requirement refinement. It have been developed focusing on space systems case studies, including software analysis, satellite operations modes and missions requirements. This paper describes the technique called COFI-ref (COnformance and Fault Injection for Requirement Refinement) methodology with a small ex...