Armach Robotics HSR | In operation brushes and optimising the design was an important part of the development effort, and is still subject to refinement. Much of that work was also done in cooperation with the FIT, Lander says. “We developed our own design for the brush heads, focusing on howmuch independent movement they would need to adjust to the contours of the ship’s hull, and howmuch is reasonable to be able to build into a system to ensure good contact around a number of different surface shapes,” he says. This involved finding the right combination of brush flexibility, head movement and number of brushes that work best on a robot of its size. “We have five brush heads on the vehicle, so each one has a bit of independent movement to handle some flex and curvature,” he says. “Since the vehicle is a metre long and two-thirds of a metre wide, there are complex shapes on a ship that we can’t yet crawl on, but for larger ships we can get onto probably 95-98% of the hull.” Hull conditionmonitoring The data on the hull’s condition is potentially as important for the ship’s operator as the cleaning, and consists mostly of location-referenced visual imagery, although sonar imagery is also collected. The imagery allows Armach to provide a detailed report documenting the pre- and post-cleaning conditions. Processed using software developed in-house, the feedback data allows a variety of impending problems to be detected and identified before they become more serious and expensive to rectify. “We will be able to report on areas of excessive growth, coating failure, anode wear, and detect any other anomalies on the hull,” Lander says. “And we will be able to provide better comparisons between inspections. “We also expect to add additional inspection capabilities to the HSR to allow for more detailed examinations that can support class inspections and help with pre-dry-dock maintenance planning.” Efficiency drive Efforts are continuing to improve the efficiency of the cleaning process and to make it faster, which are being embodied in a new and more easily manufacturable version of the HSR. “We are going to have a slightly larger cleaning path, and the brush size has gone up a bit,” Lander says. “We have been learning more about the relationship between brush size, bristle density and robot speed. There is a magic number of how many bristles should hit a spot per second, so even a 4 in difference in size on something that’s only 24 in wide makes it 15% faster, and that’s a big deal for the efficiency of a little robot on a big ship.” Cleaning time is highly dependent on vessel size, but Armach aims to clean a 300 m cruise ship in 8 hours using multiple robots. Time in port is a major constraint for cleaning a cruise ship, he points out: “It’s only in for 8 hours and we don’t want to disrupt its schedule.” Frequency of cleaning is governed largely by a vessel’s operational profile, he notes. “Armach works with each vessel to determine the schedule in accordance with the vessel’s bio-fouling management plan.” EverClean is offered as a subscription for an ‘always clean’ hull rather than single cleaning operations. “That said, costs are such that the fuel savings are more than enough to cover the costs,” Lander says. While multiple robots can work on the same ship, it takes one or two people to operate each HSR. However, Lander says Armach is working towards allowing multiple robots to operate autonomously, with only one person providing oversight of them all. Resident robots Looking ahead, EverClean is moving towards installing HSRs aboard vessels as resident systems. They will need only minimal engagement from the ship’s crew, Lander says, as they will be overseen from a remote operations centre in the US. “That will change the way we approach the operation, because it gives the robots more freedom to operate for longer periods. As we don’t face the issues that we would with a battery-powered robot, it’s not going to run out of power. Also, we can operate in the dark, so with a resident system and the vessel at anchor we can do the cleaning around the clock.” This approach, he says, suits tankers and container ships, for example, that often sit at anchor for long periods waiting for a port to grant entry or for a pier space to become available. Proactive cleaning is a big idea, Lander concludes. “Having clean ships sailing the ocean is a better long-term solution than allowing fouling to build up before cleaning them.” 113 Uncrewed Systems Technology | June/July 2023 Length: 1 m Width: about 66 cm Weight: 30 kg Propulsion through water: electric thrusters Propulsion on hull: electrically powered rubber tracks Power source: shoreside or shipboard generator through tether Control: manual ‘flying’ to hull and supervised autonomy Comms: 4G cellular or satellite link to Armach control centre Cleaning effectors: rotary brushes Some key suppliers Autonomy and sensor data processing software: Greensea Systems Fibre optic gyro: Emcore (formerly KVH) Doppler Velocity Logger: Water Linked Multi-beam sonar: Blueprint Underwater camera: Sidus Solutions Specifications
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