An autonomous ‘air-ground payload transfer device’ with truly disruptive capabilities for drone delivery applications is set to replace winches.

The device, called SPARROW and developed by BMT, is a new type of lightweight suspended robot that descends on a line with the payload leaving the drone at height. While the drone remains in the approximate overhead, SPARROW has autonomous control of its descent while making horizontal adjustments for safe, quiet delivery. This allows the drone to remain much higher above the destination, unheard and unobtrusive at ground level, compared to when using a traditional winch.

Simon Gould, BMT Managing Director for Defence and Security UK, commented, “At BMT, we have an outstanding heritage and commitment to research and innovation that help to shape the ideas of tomorrow. This fully autonomous robotic concept is a great example of how we actively apply innovation to solve our customers’ complex problems. We are looking forward to seeing how this novel solution can help operators in a diverse range of applications and settings.”

Replacing a traditional drone-mounted winch, BMT’s novel robotic device (patent pending) lowers both itself and the payload at the bottom end of a low-profile, weight-bearing line (exactly where precise control is needed), with just the top end of the line attached to a 3rd party drone above. To provide autonomy, SPARROW has an internally powered cable drum, four small side-facing rotors, and all the necessary sensors, power, and processing. The drum rotation is controlled by an in-hub motor and brake, allowing a rapid and silent descent and ascent. The rotors do not generate lift and only operate when required to push sideways to counter the wind or move the payload horizontally.

The SPARROW concept enables the large, noisy, vulnerable drone to remain high above the complex ground environment at the destination. Just how high depends on the use case and wind strength; but safe controlled delivery is possible using this approach from 200ft in windy conditions, and 500-1000ft in light winds. In comparison to using a traditional winch from a low hover, a SPARROW delivery offers a much smaller, quieter physical presence at the point of delivery. It also allows a safer, more precise delivery to a wider variety of locations, including confined spaces close to vertical surfaces and urban infrastructure.

This approach may also offer value to manned helicopter operations and across other domains such as Maritime Ship-Shore deliveries, support to maintenance engineers on tall structures, Emergency Services, and commercial drone delivery to domestic addresses. The project is looking to partner and licence the technology to a range of leading established suppliers.

If trials continue to prove successful, BMT is offering an alternative vision of the future in which the environment is not filled by the buzzing of drones hovering in close proximity to people, but one where drones remain safely at height, out of sight, out of earshot and out of mind.

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