- No operator: So, we are now at the point where we can drive our tractor to the starting point in the field, the designated starting point of the predetermined course and then let the tractor automatically follow this path as accurately as it can; all the while controlling the applicator and the tractor until it gets to the end point of the course. The operator on the tractor is literally going for a ride. Why are they there at all? Some would argue that an operator is needed to monitor the process and be able to intervene just in case ‘something goes wrong’. I harken back to the days when my Dad put me on the tractor and told me that if something goes wrong, just stop the tractor and walk home. The same thing could be said here, if the computerized control system detects something wrong, it could simply stop the tractor and message (text) the farmer of what fault it has detected. The farmer could then go out to the tractor and investigate and remedy the situation.
Another argument for having an operator is that someone is needed to look out for intruders in the field such that the tractor does not drive over them. I see three levels of security here. First there could be a motion detector or infrared detector that could detect intruders. Secondly, a mechanical bumper could be placed in front of the tractor and applicator such that if it encountered or touched anything it would immediately stop the machine. And thirdly, an independent program could be checking to see that the tractor is always within the bounds of the field. If the tractor is ever caught outside the perimeter of the field, or within the boundary of an obstacle, it would immediately shut down.
There is also the thinking that driving a tractor is much too complicated for a machine to anticipate all that could go wrong. A little story is in order: Imagine years ago, maybe in your grand parents era, that a travelling salesman comes into the farm yard selling automatic washing machines. He explains to your grandmother, that all you have to do is put your clothes in, set the thing going, and you can walk away and do something else. A half hour later you can come return and your clothes are done – clean, and ready to hang on the line. This is incredible, and your grandmother says this is hogwash, impossible and she chases the salesman out of the yard. Later she goes in for dinner and tells everyone the incredible story of the automatic washing machine. Crazy, just how would this machine be able to pick up the clothes and put them through the wringer? How would this machine be able to monitor when things go wrong – like when the clothes wrapped around the wringer. No way the machine would never know how to reverse the wringer. The point here is that machines can be designed to be automated, and they can mitigate the faults. Manually driven machines, often fail when the operator pushes that machine beyond its design limits. If you get too close to that slough, you will get stuck.
To remove the operator from the tractor and have it completely autonomous; more than a course to follow is needed. The control system must have complete reliable control of the tractor, the steering, the powertrain and the brakes. Also control of the applicator is needed – turning it on and off at precisely the appropriate time. Monitoring the tractor and the applicator for overheated bearings, oil pressure, water temperature, and air pressure in the tires. Instrumenting and monitoring the tractor and applicator are all within the realm of today’s technology and in fact most of this monitoring is already being done today. The difference is that the results are now being sent to the operator, whereas with an autonomous system the monitored measurements would be relayed to a remote location – perhaps to the farmer’s cell phone while sitting in his half ton. Security to make sure that the tractor does not drive over someone or something. This could be achieved with layers of security. As earlier mentioned, the first level would be a motion detector and/or an infrared scan. The second tier of protection could be a mechanical bumper, and a visual video analysis of what is in front. To ensure that the tractor is always in the field, an independent software program could always be checking. A good reliable communication link would be needed from the tractor to the farmer, who may be miles away. If a fault or something unusual was detected, or perhaps the tractor just needs servicing, fuel or more inputs such as seed or fertilizer – it would need to be able to inform the farmer of its status. In most cases it would quietly do its job, and only demand attention when extenuating circumstances arose.
The advantages of removing the operator from the tractor are many. The most obvious is that you do not have to utilize the time and abilities of the operator on such a mindless task. The tractor could be much cheaper without the cab, air conditioner, and all the other comforts and amenities an operator requires. So, the tractor itself would cost less. Yes, you would need the computer and electronics to do all the steering and automatic stuff, but it pales in comparison to the cost of the cab and operator. I have heard that half the cost of a tractor goes into the comforts and conveniences of the operator. And since we don’t need the air conditioner and will have less weight without the cab, the fuel use could be reduced. An air conditioner can use 15 HP. Another advantage in having the process automated is that since we are not concerned about the operators time, the machine can operate 24/7, it needs no rest, it does not take holidays and it can drive in the dark. The speed of the tractor can be lowered and kept within the design limits of the machine, and at speed, optimum for that operation. This will save fuel and minimize the amount of break downs since it is not being pushed to the limit. But perhaps the greatest advantage in going automatic without an operator is that one can now have smaller tractors and smaller implements which it turns out are more efficient, as will be demonstrated in the next section.