Issue 45 | Uncrewed Systems Technology Aug/Sept 2022 Tidewie USV Tupan | Performance monitoring | Bayonet 350 | UAVs insight | Xponential 2022 | ULPower UL350i and UL350iHPS | Elroy Air Chaparral | Gimbals | Clogworks Dark Matter

30 Dossier | TideWise USV Tupan Landing pad The UAV’s landing pad is also made of aluminium, as a compromise between weight and robustness. The team concedes that composite materials could have lower weight-to-strength on paper, but the hardness of composites could be insufficient for avoiding damage during hard landings. “Another reason for choosing aluminium for the landing pad is its excellent energy absorption properties,” Coelho adds. “During harder landings, we don’t want the UAV to bounce back upwards or along the pad’s length, so the easiest way to avoid that is to have a structure that’s very good for bending or ‘shivering’ a little to absorb such impacts.” Joyeux says, “The key to a successful landing is to minimise the relative motions between the two bodies – that is, the UAV and the pad. To achieve that, we contracted Stable, in Norway, a specialist in stabilised platforms and other items such as furniture for marine vessels, to develop an actuated, gyro-stabilised gimbal to sit under the landing pad. We are now on the second generation of that system, and it runs smoothly.” A mechanism for catching the UAV and holding it securely atop the landing pad has been designed by TideWise, and is in the process of being patented. It draws the UAV inward from wherever it is in the 1.7 sq m area of the pad to within the 0.45 sq m centre – matching the UAV’s landing footprint – in less than 3 seconds, without damaging the UAV. This proprietary mechanism is the result of several prototypes. Referred to in-house as the ‘hashtag’, four bars are electromechanically actuated from the perimeter of the pad into its centre, with just enough force to slide the UAV’s legs into the middle (if offset) while trapping them to avoid knocking it over. “We’re on the second generation of the hashtag too,” Coelho says. “On the first version, the bars moved parallel to each other, but now they rotate in the four corners of the landing pad, in a way that creates a special shape and reduces in size at the ideal rate for capturing the UAV.” Survey systems and integration The selection and combinations of sensor payloads on the Tupan are dictated by customer demand, and the biggest demand is for ocean data, including stabilised 360 º electro-optical cameras, multi-beam sonars, motion sensors, water quality measurements such as salinity pH levels, and water current data from ADCPs. Coelho adds, “We use Eiva’s software to collect and process the data; they’ve been doing marine data acquisition and related solutions for many years now.” August/September 2022 | Uncrewed Systems Technology USV Tupan Diesel-electric Differential thrust Dimensions: 4.95 x 1.78 x 0.6 m Full displacement: 1400 kg Unladen displacement: 1100 kg Maximum speed: 6 knots Maximum endurance: 12 days Payload capacity: 200 kg nominal Some key suppliers Simulations: Open Robotics (Gazebo) Data collation and processing: Eiva Stabilised platform gimbal: Stable Diesel engine generator: WhisperPower Onboard battery charger: WhisperPower Propulsion electric motors and controllers: WEG Rudder mechanics and motor: Jefa Rudder motor controller: Roboteq GNSS: u-blox IMU: AceINNA Wind sensors: LCJ Capteurs Survey motion unit: Applanix Multi-beam sonars and data acquisition: Norbit Lidar: Velodyne Main computer: COTS SBC: Seeed Studio Coaxial cables: AF Datalink Antennas for wi-fi and cellular: Poynting Networking equipment: Mikrotik COFDM radio: Domo Tactical Communications Satcom antennas: KVH GNSS antennas: Tallysman AIS transponders: Em-Trak Specifications While the UAV can capture data on assets high above the water’s surface, the Tupan can use sonar or other sensors for inspecting assets at or deep below the waterline