Robots are go


FORGET about working around the clock to make the best use of soil moisture. If a Queensland team led by John Billingsley is on target, you can stay in bed and have the tractor do it for you.

At the National Centre for Engineering in Agriculture, Professor Billingsley's team has been tine-tuning the accuracy of global positioning systems (GPS) to the point where a robot tractor could take on the business of row crop planting. The refinement brought GPS accuracy down from plus or minus 10 metres to plus or minus 2 centimetres. That will get a tractor through a tight gateway with room to spare.

The brain of the test robot was a bush walkergrade GPS receiver on the tractor linked by radio to an identical receiver used as a base station. The system is practicaland affordable and the broad acre farm of the future could see a number of small machines chugging away quietly night and day seeding, cultivating or whatever, with never the need for a smoko.

The sedate pace of the work means that any malfunction would result in minimal damage, with the tractor wedging up on a safety bumper, stopping and automatically radioing home for help. Professor Billingsley said, "The guidance bit works though it needs more development for commercialisation - but the big problem will certainly be interfacing it with the farmer. A lot of tasks are cut and dried and held in the on-board computer, like 'Go down the row and spray anything that looks likely ' or 'When you get to the end of the row, duck into the next one, keep going until there are no more rows, then come home'. But we are certainly working on the idea of incorporating commands into the data stream. The most likely scenario to use this, though, is for the robot to sit in the middle of the field and bawl for help. The farmer looks at a TV image that it sends and replies, 'You've just met a possum. Shut up and get on with it!'"

Bushwalker-grade GPS became a lot more accurate last year when the USA terminated Selective Availability, the technology that distorts GPS, preventing hostile forces or terrorist groups from using it to target weapons. Professor Billingsley says the new method places an each-way bet - it uses the radio carrier wave, rather than the 'message' , so it would still work if the US President faced the wrath of yachties and motorists and switched Selective Availability on again.

Program 5 Contact: Professor John Billingsley 07 4631 2513 email

Region North