Serge Montambault

LineScout Technology: Development of an Inspection Robot Capable of Clearing Obstacles While Operating on a Live Line

Robotic systems are used in a range of applications to carry out inspection and repair tasks in hostile environments and in otherwise inaccessible locations. Applied robotics has found several niche applications in Hydro-Quebec operations. One example of a recently developed robotic solution for power line applications is the LineROVer Technology. Now that the technology has proven its worth for power system applications, the next logical step in the project is to develop a vehicle capable of clearing such obstacles as insulator strings, vibration dampers, aircraft warning spheres and corona rings. It must also clear spacer dampers and insulator strings as it travels along conductor bundles. The LineScout robot developed meets this requirement and can clear obstacles as it travels down a line. It can move along several axes, allowing it to adjust its shape in real time to various line configurations and to a wide range of obstacles while remaining as light and compact as possible. The robots geometry was engineered to give it at least six possible obstacle-clearing sequences, making it versatile in unforeseen situations. The robot can operate on an energized line, has one-day battery life and can be remotely controlled 5 km away. The control approach and electronics allow intuitive human operation of the robot. Moreover, it can operate semi-autonomously, learning to clear obstacles by means of automated sequences. The LineScout Technology described in this paper is a versatile moving platform that extends live-line inspection capabilities and lends itself to future power line repair work

Field-oriented developments for LineScout Technology and its deployment on large water crossing transmission lines

Condition assessments for power transmission line infrastructure and conductors are essential to maintain a reliable and efficient system. LineScout is a high-performance robot designed to undertake detailed, comprehensive inspections of transmission lines, which contributes to maintaining the integrity of equipment and the safety of inspection crews. This paper outlines Hydro-Quebecs LineScout Technology, describing briefly the main systems and key design issues and discussing the technologys impact and benefits on power transmission line inspection and maintenance practices. The paper then focuses on field results gathered over the past 2 years with LineScout Technology. Very important lessons were learned from more than 20 field deployments of the robot on live transmission lines. An appreciable amount of significant feedback came from these field visits and was decisive in improving the technology. Specifically, transportation and installation methods and onboard energy management strategy are presented. Also discussed, for the first time, is a simplified wheel contact radius estimate, useful for improving the wheel odometer readings. Finally, one field deployment on a large water crossing transmission line is presented in detail. The paper discusses the importance of the work done and of newly implemented features in terms of the quality and efficiency of inspections, the reliability of systems, and the safe operation of the technology.

Design and Validation of a Mobile Robot for Power Line Inspection and Maintenance

This paper presents the LineScout Technology, a mobile teleoperated robot for power line inspection and maintenance. Optimizing several geometric parameters achieved a compact design that was successfully tested over many line configurations and obstacle sequences. An overview of the technology is presented, including a description of the control strategy, followed by a section focusing on key aspects of the prototype thorough validation. Working on live lines, up to 735 kV and 1,000 A, means that the technology must be robust to electromagnetic interference. The third generation prototype, tested in laboratory and in field conditions, is now ready to undertake inspection pilot projects.

LineScout Technology: From inspection to robotic maintenance on live transmission power lines

Power line inspection and maintenance practices are evolving as changing market regulations, significantly increased line loading and system availability requirements put pressure on grid owners to innovate. Robotics is thus making its debut in that field. Described in previous papers as an inspection tool, Hydro-Québec LineScout Technology is evolving into a teleoperated mobile robot capable of performing basic maintenance tasks. Programmable pan-and-tilt camera (PPTC) units were designed and implemented as the first step towards enhanced teleoperation control. LineArm, a dual end effector robotic arm, was specifically designed for work on bundled conductors. Design specifications and kinematics of these two subsystems are presented. Implemented application modules to be mounted on LineArm are also presented and their utilization is reported as a milestone in power line live maintenance. Lastly, future work and challenges in applying robotics to transmission line maintenance are briefly discussed.

Reliable and intuitive teleoperation of LineScout: a mobile robot for live transmission line maintenance

Power line inspection and maintenance is a slowly but surely emerging field for robotics. This paper describes the control scheme implemented in LineScout technology, one of the first teleoperated obstacle crossing systems that has progressed to the stage of actually performing very-high-voltage power line jobs. Following a brief overview of the hardware and software architecture, key challenges associated with the objectives of achieving reliability, robustness and ease of operation are presented. The coordinated control through visual feedback of all motors needed for obstacle crossing calls for a coherent strategy, an effective graphical user interface and rules to ensure safe, predictable operation. Other features such as automatic weight balancing are introduced to lighten the workload and let the operator concentrate on inspecting power line components. Open architecture was considered for progressive improvements. The features required to succeed in making power line robots fully autonomous are also discussed.

LineScout Technology Opens the Way to Robotic Inspection and Maintenance of High-Voltage Power Lines

Historically, the inspection and maintenance of high-voltage power lines have been performed by linemen using various traditional means. In recent years, the use of robots appeared as a new and complementary method of performing such tasks, as several initiatives have been explored around the world. Among them is the teleoperated robotic platform called LineScout Technology, developed by Hydro-Québec, which has the capacity to clear most obstacles found on the grid. Since its 2006 introduction in the operations, it is considered by many utilities as the pioneer project in the domain. This paper’s purpose is to present the mobile platform design and its main mechatronics subsystems to support a comprehensive description of the main functions and application modules it offers. This includes sensors and a compact modular arm equipped with tools to repair cables and broken conductor strands. This system has now been used on many occasions to assess the condition of power line infrastructure and some results are presented. Finally, future developments and potential technologies roadmap are briefly discussed.

LineScout power line robot: Characterization of a UTM-30LX LIDAR system for obstacle detection

This paper presents the characterization of the Hokuyo UTM-30LX laser range finder applied to obstacle detection on power line conductors. First, an overview section defines requirements and explains why the UTM-30LX was selected for this application. Next, since there is no published characterization of this particular sensors performance, a comprehensive set of experiments is described, both general tests and ones specific to the novel problem of scanning a power line conductor to detect where obstructions are present. It is then explained how the LIDAR can be mounted on the LineScout power line robot and what algorithm is used to detect obstacles ahead. Basic results obtained on a full-scale power line mock-up clearly demonstrate the potential of the approach.

Field experiences using LineScout Technology on large BC transmission crossings

A shared dedication to safety, transmission reliability, and the use of innovative technologies to improve business practices brought together Hydro-Québec and British Columbia Transmission Corporation (BCTC) in the field deployment and enhancement of a high-performance power line inspection robot. Since 2003, Hydro-Québecs research institute (IREQ) has been developing LineScout Technology (LST), a mobile robot capable of crossing many of the obstacles found on live transmission lines, which consists of a modular platform onto which various sensors and tools can be deployed. Consequently, BCTC Research and Development Department (BCTC R&D) engaged discussions with the IREQ team in 2006 and developed over the years a very fruitful collaboration in deploying and improving this technology. Field experiences in British Columbia with the LST demonstrate that it is ready for deployment in inspection practices on different transmission networks around the world. Furthermore, this paper shows how collaboration between utilities can leverage the assets of each partner and lessen several obstacles likely to be found in the path of introducing robotics for transmission line inspection and maintenance.

State-of-the-art review of computer vision for the management of power transmission lines

A review of the current state-of-the-art computer vision applied to the management of power transmission lines is presented. It covers the highest value applications for electric utilities, with a specific interest for applications dedicated on the cable system. Although robotics provides additional means of data collection, this review is not centered on specific platforms. Strategic steps that could favor the efficient introduction of computer vision in the power transmission industry are also discussed.

Introduction of a LIDAR-based obstacle detection system on the LineScout power line robot

This paper is a sequel of an earlier paper that featured a thorough characterization of the Hokuyo UTM-30LX laser range finder, which showed promise for a specific application: allowing a power line robot to detect obstacles in its path. After a quick summary of the earlier conclusions, this paper pushes the validation farther by assessing for the first time this popular LIDARs performance when subjected to the particularly challenging, outdoor, power line environmental conditions: large temperature range, changes in lighting, strong magnetic fields, and oscillating or vibrating targets. Use of return signal intensity, predictably affected by the angle of incidence on the target and by target surface finish, is also investigated as a means to detect variations due to an obstacle. Scanning results with LineScout traveling at maximum speed on a full-scale power line span are then analyzed to validate the proposed detection thresholds.