Unmanned Systems Technology 033 l SubSeaSail Gen6 USSV l Servo actuators focus l UAVs insight l Farnborough 2020 update l Transforma XDBOT l Strange Development REVolution l Radio telemetry focus

Servo actuators | Focus UUV actuators UUVs have to endure far higher pressures than UAVs, and their servos must incorporate more rigorous sealing while still allowing free output shaft movement. This is of course to prevent saltwater ingress that would rapidly corrode the geartrain – rendering the actuator inoperable – and destroying the motor, processors and sensors. For UUVs operating down to 2000 m (where pressures exceed 200 bar) or deeper, some actuator companies now use oil-filling systems to pressurise their enclosures, compensating for the pressure outside. This typically requires major modifications to the housing to enable free flow of the oil, as well as a connection to a pressure compensator pump that will add or subtract oil from the servos as needed to keep the oil pressure slightly above the external water pressure. Customising these servos for different UUVs is prevalent, to cater for the different pressures at different operating depths, as well as variations in UUV architectures. For example, some customers want oil to flow from one servo to other servos and systems. Such engineering is now being put to the test even further, as the past two years have seen new UUVs being built for civil and military operations down to depths of 6000 m. While the gearbox, motors and ball bearings are comparatively unaffected by the quantities of oil such depths require, chips and processors can suffer major problems. If the plastic enclosure of a servo’s CPU for example is too exposed to the pressure of the oil (and its viscosity at 6000 m or so), the chip can become damaged. Oscillators made from piezoelectric crystal are especially vulnerable to oil ingress. While they are often housed in their own metal enclosure – and OPV servos are useful for testing new autopilot hardware and software, such as when using manned aircraft to trial autonomy 888-321-9178 | 631-298-9179 | [email protected] | ultramotion.com | Cutchogue, NY • High bandwidth professional linear servo actuator • Brushless DC control electronics built-in • Ultra reliable, contactless absolute position feedback • Hardened against shock, vibration, and liquid exposure • Lightweight, high power density • Multiple communication protocols supported including RS-422 serial, CANopen, RC PWM, 4-20 mA, and more A1 series: Standard Servo Cylinder A2 series: Industrial Servo Cylinder AU series: Subsea Servo Cylinder AM series: Ruggedized Servo Cylinder