Integração, Flexibilidade e Tempo Real: Critérios Críticos no Desenho de uma Solução de Inspecção de Linhas*

by João Gomes Mota, Carlos Silva

* Integration, Flexibility and Real-Time: critical design criteria for the design of an over-head line inspection solution

presented at XII ERIAC, 12^th Meeting of the Iberian-American Region of CIGRÉ (XII Encontro Região Ibero-Americana do CIGRÉ), May 20^th - 24^th, 2007, Foz do Iguaçu, Brasil.

Snapshot of flight interface in clearance analysis mode

Abstract in Portuguese

Este artigo descreve o processo de concepção e implementação de uma solução de inspecção de linhas aéreas orientada pelos princípios de integração de modalidades de inspecção; flexibilidade dos equipamentos, procedimentos e tratamento dos dados; obtenção de resultados em tempo real que permita aos inspectores analisar e reagir imediatamente aos pontos de interesse detectados ao longo da linha. Supletivamente, foram considerados critérios de integração de bases de dados e expansibilidade.

A solução proposta baseia-se no uso simultâneo de sensores vídeo, termografia, laser, GPS e outros, dando competência aos inspectores para efectuarem múltiplas inspecções numa única passagem pelas linhas e combinando a experiência humana dos inspectores com a informática e o processamento de sinal em tempo real que permite reforçá-los em tarefas que envolvem grande intensidade numérica.

A solução destina-se às linhas eléctricas de transmissão e distribuição, às inspecções efectuadas pelo ar ou ao nível do solo. São descritas as funções já desenvolvidas de registo digital dos dados de inspecção, interface com os utilizadores e detecção automática de obstáculos na faixa.

O artigo inicia-se com a discussão do caderno de encargos e das especificações; na segunda secção apresenta-se a arquitectura da solução, justificando-se as opções tomadas; a terceira secção descreve as funções principais; de seguida, analisa-se o desempenho de algumas configurações no campo, os constrangimentos encontrados e as alterações efectuadas para os minimizar; na última secção avalia-se o projecto e lançam-se pistas de investigação para melhorar a inspecção de linhas.

Abstract translated and extended

This paper describes the reasoning behind the design and implementation of an over-head line inspection solution founded on: integration of multiple inspection types, flexibility on hardware, procedures and data processing and real-time results that enable inspectors to analise and act upon relevant issues as they travel along the line. In addition, database adequacy and expansibility were also considered.

The proposed solution is based on the simultaneous use of video, thermography, laser and GPS sensors, among others, enabling inspectors to perform multiple inspections in one single pass along the lines. It combines the human experience of inspectros with software engineering and real-time signal processing; human and machines reinforce each other and humans can be assisted in number-crunching tasks.

The solution fits both transmission and distribution lines; it can be fit onto cars of from the air.The functions already completed are described for: digital recording system, user interface and automatic clearance detection.

The paper begins with a requirements justification discussion; in the second section the solution architecture is introduced; the main functions are described in the third section; then, field results are reported on the next section including the challenges found in the field and the modifications performed to minimise those issues; in the last section the project is evaluated and new lines of research for enhancing over-head line inspection are proposed.

1. Introduction

The goal of the endeavour was to integrate all inspection modes and features in one single airborne inspection to minimise helicopter use and maximise the value of each pass. Moreover, inspecting all the issues simultaneously offers a better insight into the line condition.

Flexibility is important because companies doing over-head line inspections often have a great deal of hardware they want to keep on using. Therefore, any new solution should be modular and integrate existing modules while keeping the possibility to improve as the needs arise.

Other features were considered necessary: digital recording, time and spatial reference of all data, synchronisation of data flows and connection to asset databases.

2. Architecture

The proposed architecture is based on complementarity of people and equipments. Equipments are used to perform repetitive and quantitative tasks and to supply data so that inspectors can make qualitative evaluations and take decisions.

The software architecture is based on a ground module that acts like a server and provides data recording and synchronization and all sensor and client modules build upon it and communicate through the recording server.

3. Main modules developed

The following main modules have been developed:

Digital Recording Server

executes Device Manager tasks, records data in files and databases, provides the inspector with support information (elapsed time, remaining disk space, mission route), Index and Search during one mission or across missions, data extraction to get the data form the Digital Recording Server into an office computer and quality control. All data is accessed and viwed through an HTTP server.

Web interface

the real time viewer for inspectors to command and monitor the inspection process. It includes, video, LiDAR, sensor status and many more informations.

Track Clearance (or Right-of-Way)

Based on real-time processing of LiDAR data, this module classifies range samples into one of four categories: line, ground and obstacles and computes the clearance distances instantaneously.

4. Experimental results

The system has been demonstrated with the simultaneous recording of three video channels in PAL format, two audio channels, LiDAR data and GPS data. The flight interface has been demonstrated in a TabletPC with touchscreen using Java, ActiveX and Javascript technologies over an HTTP interface.

5. Conclusions, constraints and future developments

The project started as a response to EDP needs for over-head line inspection and it was designed to meet the economical, technical and aeronautical constraints already on the ground. Power and weight limits and flexibility to mount, unmount and replace sensors meet or exceed expectations. An expansion to ground vehicles has been envisaged.

Keywords

Manutenção preventiva, inspecção de linhas, equilíbrio ambiental, integração sensorial, laser, vegetação, faixa da linha, termografia, defeito, helicóptero.

Keywords translated

"Preventive maintenance, over-head line inspection, environmental balance, sensor integration, laser, vegetation, right-of-way, thermography, anomaly, helicopter"