PNT Roundup: Inertial, acoustic, lidar, Wi-Fi and beacon news

Independence, redundancy at sea

Acoustically aided inertial navigation technology will enable a specialized sea vessel maintain dynamic positioning through GNSS disruptions in challenging environments.

Sonardyne Inc.‘s dual Ranger 2 Pro DP-INS systems aboard the ultra-light intervention vessel Brandon Bordelon will track remotely operated underwater vehicles (ROVs) during inspection, repair and maintenance activities, providing an independent position reference for the ship’s Marine Technologies Class 2 dynamic positioning system.

The Lodestar motion sensing instrument platform (attitude and heading reference system, or AHRS) is tightly integrated with Sonardyne’s acoustic positioning components, providing power and control of surface and subsea transceivers as well as instruments such as Doppler velocity logs. The seamless integration of acoustics and inertial technologies exploits the long-term accuracy and precision characteristics of acoustic positioning with the continuous availability and fast update rate from high-grade inertial sensors.

Specialized vessels such as this normally rely on GNSS and ultra-short baseline (USBL) acoustics as their primary sources of dynamic positioning reference data. However, a vessel’s station-keeping capability can be compromised if the USBL is affected by noise or thruster aeration and the GNSS signal is simultaneously interrupted. GNSS signal interruption is particularly common around Equatorial regions and during periods of high solar radiation.

Wideband Acoustic. The integrated acoustic-inertial system addresses this vulnerability, exploiting the long-term accuracy of Sonardyne’s Wideband  2 acoustic signal technology with inertial measurements.

The resulting navigation output can ride through short-term acoustic disruptions and is completely independent from GNSS.

The equipment includes Sonardyne’s ship-mounted inertial navigation sensor and two HPT 7000 acoustic transceivers. The HPTs have been installed on the Brandon Bordelon through hull deployment poles and are optimized for tracking and dynamic positioning in ultra-deep water.

The equipment includes three ring laser gyroscopes that measure the angular rate and three accelerometers that measure the specific force of the moving platform. The INS output is low noise and accurate in the short term, but degrades over time. Therefore, it must be seamlessly aided with complimentary acoustic positioning observations.

Ranger 2 DP-INS uses a tightly coupled integration of range and bearing measurements from seabed transponders to aid the INS and control integration drift.

Industry effort pushes beyond-LOS UAV flight

At the International Lidar Mapping Forum in February, two organizations announced an industry consortium to push for removal of barriers to use of drones in long-distance inspections.

The presentation by Sharper Shape and Edison Electronic Institute made the point that UAVs — specifically, lidar-equipped UAVs — offer potential for more frequent and more affordable inspection and data capture for overhead assets such as power lines. Currently, Federal Aviation Administration (FAA) regulations restrict commercial operations to visual line of sight (VLOS). The EEI Sharper Utility project will advocate for beyond visual line of sight (BVLOS) flights.

The presentation explored such issues as:

• Types of information obtainable during UAV inspections and how that information can be used to improve infrastructure and asset management programs.
• How UAVs provide a cost-effective alternative to traditional inspection methods, and the critical factors contributing to cost-efficiency.
• Why industry-wide coordinated effort is required to institute change.
• Steps and the key principles to enable commercial-scale drone operations for the electricity industry.
• Identification of stakeholders and the regulators.
• The anticipated date of permitted BVLOS drone flights in U.S. utility inspections.

The Eyes of Texas. In related news, Xcel Energy announced a UAV flight research and development mission that traveled beyond the operator’s line of sight during survey of a transmission line in the Canadian River Breaks region north of Amarillo, Texas, in early February. Two contractors piloted the lidar-equipped Vapor 55 drone. Xcel began using unmanned aircraft to visually inspect substations in 2015, and is the first utility to receive and use the FAA’s certificate of authorization to perform a mission for research and development purposes beyond visual line of sight.

Xcel Energy inspects 320,000 miles of electricity and natural gas infrastructure, including more than 1,000 substations, gas regulator stations and dozens of major power plants in eight states. GPS World will carry further news of this flight in a subsequent issue.

Indoor Nav at Vast Mobile World Congress

Add Infrared Aiding in Retail Show

A scalable indoor positioning hybrid technology from Pole Star of Toulouse, France, combining GPS, Wi-Fi, Bluetooth Low Energy beacons, and motion sensors, and MOCA of Barcelona, Spain, with a location-based mobile engagement platform, provided show navigation, guidance and tracking for the GSMA Mobile World Congress in February.

The joint solution delivers three service levels that combine users’ geolocation with other data to provide expanded contextualized messages. As many as 95,000 show attendees — iOs and Android users alike — were guided through the 240,000 square meters (2.6 million square feet) of the FiraBarcelona, receiving personalized notifications from an intelligent recommendation system based on proximity.

Using geofencing, the 2,200 exhibitors could interact with attendees and attract them to theirs booths. Finally, indoor location analytics enabled the event organizers to visualize and correlate behavior and preferences of attendees.

Infrared. Pole Star also announced at the Retail Big Show in New York in January that it is integrating its NAO Campus indoor positioning technology with the Pricer Product Location solution based on Infrared trilateration. The combination will enable shoppers, once inside a store, to optimize their shopping route and be guided to the products and promotions they are looking for. Hyper-local targeting for shoppers and Indoor location-based analytics for retailers and brands are among the benefits touted.

Pricer, based in Uppsala, Sweden, offers in-store automated product positioning using infrared (IR) communication, combined with tracking algorithms to calculate the position of its electronic shelf labels (ESLs). A typical Pricer label response signal is seen by multiple points in the communication network reading different signal strengths depending on the distance from the label.

Automated in-store product positioning in retail is a “holy grail” for retailers, according to the company. By mapping in real time where the products are placed on the sales floor using the IR technology, companies can engage customers in the aisles, help customers find products and manage product placement compliance.