Ruggedized Interconnect Solutions for Today’s UAV

Drones have expanded from hobbyist or recreational uses to a broad range of commercial applications and military operations. Today, drones are also used for:

• Border/perimeter patrol
• Remote aerial sensing
• Urban and rural policing
• Surveying and mapping for forestry, oil and gas, agriculture, and package delivery
• Other mission-critical tasks

In fact, military and commercial drones are now typically used more frequently than recreational drones.

Repeated takeoffs and landings can significantly stress the UAV’s electrical system. As a result, commercial and military drones require electrical and electronic UAV interconnects that are much more durable and reliable than what’s currently being used in recreational drones.

Each component and every system used in military or commercial drones must be tested and designed to withstand extreme environmental conditions and high-performance demands. That includes electrical wiring interconnection systems (EWIS), wiring harnesses and connectors for batteries, controllers, motors, and flight control systems.

A drone failure in a firefighting or military surveillance application could be catastrophic. Failure in a medical emergency where a UAV is used to deliver medication, blood, or medical devices to an otherwise inaccessible or hostile location can mean the difference between life and death.

Military and commercial drones employ an array of electrical and electronic components in complex systems and subsystems in which reliability cannot be compromised. Electric-propulsion motors, electronic speed controllers (ESC), flight controllers, global positioning system (GPS) modules, cameras, sensors, radios, and more all draw upon a drone’s battery power. The reliability of battery interconnects is a critical factor in EWIS design.

Unlike recreational drones, which generally use power connectors and battery interconnects from varied sources with no common standards, commercial drones and military UAVs require military-grade legacy connectors that have been rated for harsh environments. However, these interconnects are typically larger and not optimal for small UAV applications where size and weight are critical considerations. Designers face a dilemma between selecting interconnects that are either underbuilt or overbuilt for UAV applications.

What’s more, the introduction of smart battery technology requires additional signal pins to support a communication link between the charging system and battery pack. Smart batteries use specialized hardware and software to report information on voltage, current, and capacity, as well as temperature, impedance, and state of health.

As an additional safeguard, a battery identification resistor is typically inserted inside the battery pack between an extra pin and ground to prevent installation of the wrong battery in the drone’s charging system. To add to the challenge, some UAV designers require interconnects developed specifically for drone batteries with exposed interconnects that must be designed to withstand the harsh environments in which the drones operate.

Making electrical and electronic interconnects rugged for use in harsh environments can add weight and volume. To help meet UAVs’ demanding size, weight, and power (SWaP) requirements, TE developed a range of high-efficiency relays, contactors, and other interconnection solutions in various shapes and sizes to handle higher voltage and amperage within a compact footprint:

Micro Circular Connectors

Based on robust MIL-DTL-38999 Series 3 standards, circular connectors such as TE’s DEUTSCH Wildcat series connectors offer a significantly reduced shell size with two housing sizes and four layouts accommodating 3, 5, or 9 contacts.

Small, Micro-, and Nano-Miniature Connectors

Compact rectangular, coax, and sealed circular connectors offer extreme weight and space savings. Small-form-factor rectangular connectors (369 series) are fully sealed for IP67 rating and accommodate blind mating. Smaller-scale connectors, like Nanonics connectors, are designed to fit micro-miniature D, subminiature, and ultra-miniature coaxial needs. The circular 8-position CeeLok FAS-T Nano connector features a 0.30-inch (7.6 mm) diameter and supports 10 Gigabit Ethernet.

Connectors for Compact Fiber Connectivity

ARINC 845-compliant EB termini (EB16) combine high performance and non-contact vibration resistance in mini sizes for single-mode and multimode fiber.Advanced transceiver modules, including ParaByte fiber optic transceivers, feature a small thermal signature and support up to 12.5 Gb/s transmission rates per channel.

Reduced Bulk Cabling

Cross-linked insulation in Raychem cabling from TE is mechanically tough, thermally stable, and much lighter compared to thick-walled, soft-polymer insulation used in conventional cable systems and cable assemblies.

Backplane Connectors for Space-Efficient Board-to-Board and Box-to-Box Connectivity

Light, next-generation high-speed backplane connectors, such as the MULTIGIG RT 3 connector, comply with the VITA 46 VPX standard and are available with reliable quad-redundant contacts and support for 25+ Gb/s data speeds

Today’s UAV projects benefit from the cross-discipline development of power-management and interconnection solutions from automotive, aerospace, energy, and rail sectors. Insights from industry standards groups — such as the Society of Automotive Engineers (SAE) — address challenges imposed by higher power and voltage levels. Standards bodies are discussing next-generation, small-form-factor interconnects for safety-certifiable embedded computing modules and systems packaging suitable for UAVs.

As the UAV market expands and innovation evolves, the temptation to employ interconnects used in recreational drones will be eliminated. Instead, using rugged interconnects for UAV electrical and electronic components will enable drones to carry out tomorrow’s critical missions.

• Drones have expanded from hobbyist and recreational uses to a broad range of commercial and military applications.
• Advances in UAV interconnect technologies have helped propel a vast drone industry that is predicted to grow to a $500 billion global market in the next decade.
• Military and commercial drones employ an array of electrical and electronic components in complex systems and subsystems in which reliability cannot be compromised.
• Each component and system used in military or commercial drones must be tested and designed to withstand extreme environmental conditions and performance demands.
• The use of drones in increasingly challenging environments is driving development of ruggedized interconnects for UAVs such as TE’s Unmanned Power (UMP) connectors.
• TE developed a range of high-efficiency relays and contactors in various shapes and sizes to handle higher voltage and amperage within a compact footprint to meet designers’ demanding SWaP requirements.
• As the market for drones and small UAVs expands, the need for development of cost-effective, efficient, SWaP-optimized interconnects designed for harsh environmental conditions also grows.