Powerline robotics is slowly becoming key tools for electric utilities. Contrary to drones that are usually limited to inspection tasks, wheeled robots like LineRanger can perform a broader range of applications. In this paper, a suite of mechanical devices is featured, as several new asset management tasks were recently added to LineRanger’s capabilities. While previous applications focused on non-contact inspection (visual, electro-magnetic, etc.), the new tasks at hand involved reaching adjacent conductors to probe line components with micro-Ohmmeter, installing and retrieving custom build sensors for multi-day line monitoring, and assessing aging conductors surface properties, to refine their thermal model and optimize the line capacity during heat waves. All three applications were recently field validated onto LineRanger, and mechanical design insights shall be presented for each module.

Even if UAVs undoubtedly had a profound effect on the visual inspection capabilities of transmission lines, rolling robots, especially for bundled configurations, will still play an extensive role in the maintenance of these strategic assets. As such, LineRanger is among the most efficient and capable wheeled platform, that can travel at an average speed of 8 km/h. In this paper, LineRanger mechanical design insights are shared, unfolding how strictly mechanical solutions deals with ease of obstacle crossing, ease of installation procedure without requiring any linemen to access the high voltage environment area, and ease of deployment of dedicated, custom-made sensors onto the line component of interest. This novel robotic platform is now being deployed onto Hydro-Quebec power grid network, performing high value applications.

In this paper, a slip-limiting controller for redundant line-suspended robots is presented. This kind of robot is usually equipped with v-shaped wheels, which brings uncertainty about the effective wheel radius, particularly when crossing obstacles. The proposed algorithm is able to estimate and limit wheel slippage in the presence of such uncertainty, relying only on wheel angular velocity measurements. Slip limitation occurs in the control allocation algorithm and hence is decoupled from the high-level velocity controller, allowing a broad applicability in centralized control approaches. Experimental results on Line Ranger show that it effectively reduces wheel slippage compared to traditional centralized control while being more energy efficient than traditional decentralized control approaches.

Robotic platforms dedicated to powerline inspection are often complex to operate, take several minutes to cross any obstacle, and must be operated by highly trained specialists. To further its goal of massive inspection of its power grid, Hydro-Québec developed an innovative robot that is simple to operate and can be used directly by line maintenance technicians. LineRanger was developed following the field deployment of LineROVer and LineScout but aims at surpassing them in terms of inspection efficiency. With an ingenious and passive obstacle-crossing system, this new robot allows large-scale inspection of bundled-type powerlines, since the obstacle crossing time is considerably reduced. In this paper, details on the robot's key features are presented along with its mathematical analysis, which guarantees its stability on flexible bundles and directly influenced the design. Finally, the LineRanger prototype is presented, with insights about its first field deployments.

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 sensor's 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.

This paper is a contribution to an invited session on the benchmarking of parallel mechanisms. The aim of the session is to compare different existing designs and prototypes of parallel mechanisms using a common set of benchmarking criteria. First, the kinematic architectures of parallel mechanisms of the multipteron family are presented. In addition to the tripteron and the quadrupteron, the pentapteron, a five-degree-of-freedom (dof) parallel mechanism is introduced. Then, the benchmarking criteria are applied to the prototypes of the tripteron (3-dof) and the quadrupteron (4-dof) prototypes. Although the tripteron and quadrupteron parallel mechanisms have been presented elsewhere, their properties, highlighted by the benchmarking analysis presented here are revealed for the first time.