Unmanned Systems Technology 023 I Milrem Multiscope I Wireless charging I Logistics insight I InterGeo, CUAV London & USA show reports I VideoRay Defender I OS Engines GR400U-FI I Ultrabeam Hydrographic Ultra-2 I IMUs

24 Dossier | Milrem Multiscope and run times of eight to 10 hours as a hybrid or up to 1.5 hours using electric power only, according to Milrem’s figures. By replacing the generator module with a second battery pack, its endurance as a pure electric vehicle increases to a maximum of three hours. The tracks provide a total tractive force of 1.1 tonnes, and enable it to climb gradients of up to 60% and traverse side slopes of up to 30%. Milrem wanted to develop a vehicle with good off-road performance and compact dimensions in relation to its payload, a combination that pushed the design team towards tracks rather than wheels. One reason for this choice is that all the propulsion, control and comms equipment can fit inside the volume encompassed by the tracks, leaving the space between the two track modules for the payload. A comparable wheeled vehicle in this weight class would be much bulkier. Another reason for choosing tracks for a vehicle in this size class is that they enable it to go almost anywhere. The ground pressure, even with a fully loaded vehicle, is less than that of a human foot, the company’s CEO Kuldar Vaarsi says, so the Multiscope can negotiate swamps, deserts and snow. “Clearly, tracked systems are more expensive from the life-cycle management and manufacturing perspectives than wheels, but in that size class the difference is not very big. Being almost fully electric is a big advantage in terms of cost,” he says, adding that maintenance costs as a result are far lower than for traditional diesel vehicles. A modular construction also keeps costs down, both in final assembly and for maintenance. If an individual module needs deeper maintenance than basic checks it can be sent away to be worked on and fitted with off- the-shelf spares in a bolt-on, plug- and-play operation. Structure, materials and layout The primary structure of each module consists of an open frame made from high-strength SSAB steel, with mounting points for a drive motor and sprocket at the front, the driven sprocket at the rear, the rubber sprung suspension arms that hold the wheels, and the front and rear track tensioners. The tracks themselves are the continuous rubber band type, from Mac’s Trax, while the rubber block suspension modules that connect the suspension arms to the frame are from Rosta. Each track module is enclosed by inner and outer side panels made from aluminium alloy. The panels are divided into bolted-on sections and quick-release ones secured by over-centre clips for easy access to the generator and battery compartments. Each track also has an aluminium alloy top cover. Physically, the two track units are held together by the payload bed, specifically by front and rear cross-beams with three bolts on each side underneath the bed; the bed itself consists of a steel grill to which various payload December/January 2019 | Unmanned Systems Technology An alternative firefighting layout puts a remotely controlled nozzle on the platform but leaves the hose connected to the fire engine (Courtesy of Milrem) Both the Multiscope and the THeMIS consist of two track modules connected by the height-adjustable payload platform and by power and data cables (Courtesy of Milrem)