Bomb disposal robot gets extra lift with actuator

The British Ministry of Defence and security services are taking delivery of Cutlass, the latest generation of robots for explosive ordnance disposal (EOD). These are being built by Remotec UK, Ltd in Coventry, to whom the actuators are being supplied.

These Cutlass vehicles will be used by the MoD for anti-terrorism operations worldwide, as well as EOD operations at home. Domestic incidents can include terrorism, crime and occasions such as failures in demolition projects and quarrying. Over the years there has also been many incidents such as old shells being used as doorstops and collections of ordnance being kept in homes.

Eighty Cutlasses have been ordered initially, which are being phased into service, with further orders expected to follow from a range of buyers.

The Cutlass is the primary replacement for Remotec's Wheelbarrow remote EOD vehicle design, which has done sterling service in Northern Ireland and elsewhere since the 1970s. It offers the latest technology in a modular design, making it capable of accommodating a wide range of payloads, sensors and tools.

A manipulator arm is equipped with a state-of-the-art gripper and has nine degrees of freedom for greater movement and agility inside limited spaces, such as the interior of a car. The actuator is used to lift the whole robotic arm to provide extra power to the internal base axis rotator gear, thus maximising its performance and helping counteract the turning moment created when a load is experience with the arm in an extended position.

David Baillie of HT Servo explains: "This sort of project usually requires a bespoke solution. We worked closely with the Remotec design team to identify maximum loads, speed requirements and other operating parameters. The best outcome would be to customise a standard actuator, as this would help contain costs.

"Fortunately the Thomson Electrak LA14 fitted the bill nicely, although we paired it with an extra powerful motor and made a few other modifications commensurate with the likely operating conditions of the Cutlass."

The actuator is based on a screw drive system so is suitable for applications requiring maximum load capacity. It is also designed to offer robust reliable performance over a long life. As an additional benefit it has a built-in anti-rotation mechanism, while its aluminium cover tube is both tough and lightweight. T-slots on the tube can be used for mounting and also allow magnetic sensors to be fitted along two sides, particularly useful as the Cutlass may be customised by or for some users.

Mobility on all terrain

The robot can either creep along at deliberately slow speeds for delicate operations, or accelerate to high speeds to enable rapid travel over a distance. The six-wheeled design offers mobility on all types of hard and soft terrain and in all weather conditions, including floods.

David notes: "Cutlass will provide the MoD with a step change in capability via a robot that is capable of adapting to new innovations in the world of bomb disposal."

The Cutlass system offers the latest technology in a modular design, thereby enabling the user to deal with the full range of both military and improvised explosive devices. Its highly versatile design means that it is capable of accommodating a wide range of payloads, sensors and tools.

QinetiQ is providing the vehicle command and control systems. The user-friendly operator command console will combine manual commands with advanced software to provide the unprecedented functionality required for such a demanding mission environment. All motion axes, including the six drive wheels on the Cutlass, are electrically driven, powered by an on-board lithium ion rechargeable battery.

David confides: "You feel a certain pride working on a job like this, especially when you are watching the evening news and you unexpectedly see a Cutlass being used for real."

For further details about linear actuators and other products from HT Servo, visit www.htservo.com.