At last: the driverless tractor!

Monday, February 20, 2012

Arable automation has really arrived with the introduction of a tractor that can handle 24-foot cultivation tools with no one in the cab. The catch: a manned tractor has to work alongside

by NORMAN DUNN

For years now, we've been promised large-scale automatic systems for cultivation. There have been plenty of smaller field robots – for soil testing, for instance. In fact, innovative self-driving machines are introduced almost every year now that satellite navigation is here to stay. But a full-blooded system of 500-h.p. or more hasn't managed to hit the headlines.

Now, it's with us. A tractor that can handle big, 24-foot cultivation tools with no one in the cab. What a time saver! What a boost to work capacity out on the fields!

There is, however, a catch with AGCO's Fendt-powered "GuideConnect" concept. There has to be another (manned) tractor working alongside. But the idea won a DLG gold medal for innovation at one of the world's largest farm equipment shows, Agritechnica in Germany during November 2011.

It's a concept that has really earned a gold award. After all, it means field output per labour unit can be doubled. And when that represents 25 acres an hour instead of just 12.5, then arable automation is making real progress.

Specifically, the manned and unmanned Fendt (and no doubt soon other AGCO steeds such as MF, Valtra or Challenger) are linked via RTK-GPS satellite navigation and wireless control. The manned machine sets the pace and directs headland manoeuvres and avoidance of any obstacles.

Fendt specialists have designed their system so that the following machine automatically stops at the end of a working pass until the manned lead tractor has completed its headland manoeuvres. Then it follows suit.

Alternatively, it remains open to the needs of the leading tractor operator who can, for example, lead the machine back down the route it has just completed for a double cultivation bout . . . or leave it sitting on the headland while the lead tractor finishes off the field.

Another alternative: when heading for home at the end of the day, the operator can signal the tractor behind simply to follow on. So far, though, the authorities have refused to consider this last permutation on the highways. But that's Europe for you. No doubt there are countries with larger-scale farming (and less-crowded roads) that will allow such a solution.

Talking of automation, the 2011 Agritechnica innovations included amplification of the "implement steers tractor" idea that really got going a few years ago when John Deere and Pöttinger launched this concept for silage harvesting. Then, sensors on the front of a tractor pulling a grass pick-up wagon automatically controlled the speed of both tractor and pick-up system according to the amount of forage in the swath. A similar system was introduced for big bale baling.

Now, Deere is back again with more on the same theme, this time in co-operation with potato harvester expert Grimme. Maintaining top crop quality is the criterion here, as well as absolute efficiency in time, fuel and labour management.

Sensors on the harvester steer the tractor to follow the potato drills exactly. The load on the elevator-chains and time required for efficient separation regulate tractor speed. On the headlands, another program steps in to control manoeuvres automatically.

What's more, ISOBUS compatibility between potato harvester controls and tractor computer system means a lot more operating information can be fed into the hardware, be recorded on-tractor and directly flashed to the farm office computer. As one engineer at Agritechnica pointed out, it's a simple step to go further and record yields, tuber damage and other parameters within the same concept.

Also making life a lot easier on the farm is new technology for the conventional front loader. With its latest "Cargo Profi" model, Fendt automates a lot of the repetitive loader operations. Fendt, and other manufacturers, now feature integrated weighing systems for their loaders that continually record how much material is being moved. Standard with some new designs are load-related shock absorbing and even automatic attachment shaker systems to get those pesky last shreds of dung off the fork. 

Electricity and field cultivations? It's also a reality now after the first showing of the Swiss Rigitrac EWD120 diesel-electric tractor. Initial power source for the Rigitrac is a conventional 120-h.p, four-cylinder diesel. But this drives an 85-kW generator that in turn powers four electric motors, one built into each wheel hub.

What you've then got is the ultimate in tractor control. Independent power at each hub means separate speeds and steering possibilities. No axles mean hydro-pneumatic suspension and hugely variable ground clearance can be added as standard. The revolutionary Rigitrac also features clever traction control software guided by torque recording at each wheel: a sort of virtual differential for each wheel.

Does the electrically powered tractor – with or without someone at the controls – represent the route ahead for modern agricultural machinery? Well, the concept saves a lot of weight, while offering much-improved manoeuvrability and comfort, so I would say we'll soon see more development in this field. BF

Norman Dunn writes about European agriculture from Germany.