Can a six-legged 'spider' tractor handle tricky transport tasks?
Sunday, June 8, 2014
The Mantis stands 2.6 metres tall to the top of its cab with five metres between opposing 'feet'
by NORMAN DUNN
A prototype "spider" tractor developed in Britain claims to reduce crop or ground cover damage during difficult transport jobs – or offer a unique cross-country transport for tourists. The so-called Mantis Hexapod from Micromagic Systems achieves this by avoiding wheelings altogether and relying on its six hydraulically powered legs to overcome demanding surfaces and obstacles.
Although payload hasn't yet been published by the designer and developer, Matt Denton, a load platform is already in place and measures 4.2 x 2.2 metres. Power comes from a 2.2 litre, 42 kW (57 h.p.) Perkins turbo diesel driving a 165 Bar (150 lpm maximum) variable displacement hydraulic pump and a 20 – 50 l /m gear pump.
Net weight is just under two tons and plenty of space has been built into the design for clearing hillocks, bushes, ditches and drains. First reports on practical applications say it could be suitable for work on sensitive areas, such as nature reserves, or as a harvest help for top fruit.
Certainly, wheelings are avoided on soft field surfaces, but can six "feet" actually reduce the danger of soil compaction damage? Only time will tell.
Wood smoke smell keeps corn clear of marauding hogs
Each year, silage corn creeps further north in Europe. It's now a major crop even in south Sweden and some parts of Finland. It brings with it a big wildlife problem, though, because silage corn has become a favourite item on the menu for wild hogs.
Shooting would be too simple for Europe. It's strictly controlled and the preserve, mainly, of licensed hunters. So a new industry has grown up, focusing on ways to scare the foraging beasts off the corn fields.
The latest introduction in this line relies on the smell of forest fires. The German firm Funke has launched a product featuring coconut-shell chips filled into hollow pipes. Funke says the coconut material is roasted to give off a strong smoky smell. "Wild hogs, in particular, fear this scent because it signifies a forest fire to them. We find that bands of hogs move off the second they catch a whiff of this scent." The company recommends that a coconut chip pipe be rammed into the field borders every 60 metres. The pipes each come with half a litre of the odorous aggregate and each fill lasts for around two months before renewal is needed. Sometimes a more natural (and less expensive) solution works even better: in Germany a plant-breeding farm protects first seedlings out in the field from hares, wild hogs and deer through scattering human hair along the plot borders. The hair is collected from local barbers and over a couple of decades has proved itself as a very effective method of warning off would-be foragers.
Robotic spraying saves costs, cuts chemical use
A fully automatic crop spraying system developed in the Netherlands claims to be unique because it features a trailed sprayer and "normal" tractor that can be detached and used for other jobs on the farm. Developed at the country's top agricultural university in Wageningen, the first users are top-fruit growers.
Research team leader Marcel Wenneker explains that there's a heightened need for automation in orchards with weekly spraying normal from April through to September harvest. "The savings in labour alone make the system worthwhile. But we can add to this increased accuracy in application which helps the environment and which also, we have found, brings savings of between 25 and 30 per cent in the amount of spray applied." GPS steering of the tractor was rejected for this application as not precise enough in valuable top-fruit orchards where maximum acceptable error in navigation is 20 centimetres. A "demonstration and playback" system was fitted on the tractor, whereby the machinery is driven around the orchard spraying route once, the route recorded on computer and then followed automatically. The current computer system has room for around 10 orchards in its memory. Additional camera control is also in place. This takes over and slows or stops the tractor and spraying operation if an obstacle looms ahead. The camera control is also linked to smartphones, so that the farmer can follow the sprayer progress at home and also stop the operation if required. The separate sprayer has its own robot control system with spray application computer linked to continuous laser analysis of the crop on each side of the route. Wenneker says this permits exact control of application volumes and high accuracy. GPS field mapping can also be fed into the sprayer system, so that application pressures can be altered to avoid drift danger at field borders or in the vicinity of waterways or ponds, for example. BF