How does GPS auto steer work??

Question

Hi there, can you please help me, I need to know as much as I can about GPS auto steer in agriculture.

Why?

How?

Set up/equipment required?

Providers?

Ongoing costs?

everything you can help me with please!!!!

Thanks in advance :-)

Answer 1

Gps works by sampling satellite signals and comparing three associated signals in your area. By determining the time difference in the signal from the three that are your locals it can place you on your map but it depends on the equipment quality just how close. Generally don't expect to get closer than a meter. Equipment receives that signal and your coordinates and then looks at your heading which is determined by and reduced to an electronic signal of it's own. Feedback equipment then uses a mechanical device, probably hydraulic contoled by a microprocesser to adjust the direction. Pre-determined directions and distances that are put into an electonically programmed memory chip determine the course and the changes are made according to exact position, direction and speed. This would require a computer with appropriate program in many cases. Sampling is done from satellites probably every thirty seconds (if memory serves me correctly) as government regulations don't allow for faster sampling rates except for military equipment. Can you guess why? Anyway I would think that the cycling of info for direction is probably multiple times a second and verified by the gps signal when it occurs. This helps when you are in large tracks of land but more for the business of farming than actual direction control. Knowing what areas have been covered with respect to seeding and pesticide application, and determining harvest quantitative analyisis with respect to, obviously the harvest/ acre or section of that.This feedback system is used in road building equipment and boats more for direction/ piloting than in farming equipment and many equipment suppliers incorporate this as well as engine diagnostics to allert the operator of any problems as they occur as well as the maintenance divisions of the manufacturer. One might not even be aware of a slight problem without this equipment. Big ships are more likely to use this as well as the huge combines (multipurpose) and huge engineering machines. Most equipment is installed in the factory but some assorted late model equipment companies build in the ability to install and update the equipment at a later time. Older equipment is a tougher update but sometimes it is made available. As to the cost, if you have to ask you can't afford it.

Answer 2

Why- Accuracy, driver fatigue, fuel, seed, fertilizer, chemical savings.

How-The first answerer gave a good explanation of how GPS works. A GPS receiver is connected to the tractor/combine/applicator's steering hydraulics and controls the steering. How much money you want to spend determines the accuracy. Most standard auto-steer systems are sub meter, but for enough investment you can get down to sub inch accuracy (this requires ground stations in addition to satelites).

Equipment required-GPS antenna, receiver, steering control box and instructions.

Providers- Outback, John Deere (Greenstar), Auto Farm, Trimble, Raven. That's not all but it's a list of the ones that have been around longest.

Cost-The higher end autosteer (sub inch accuracy) can run $50,000 +. Outback is a good sub meter system and you can get into it for under $6,000. If you subscribe to a service, there is a yearly subscription cost to get connected to the satelites, or you can use a free one (WAAS is one I use).

Answer 3

Here are a couple of sites that will explain everything to you. The last site is a commercial site that will show you something about the costs.

http://www.thelandonline.com/l_precfarm/...

http://farmindustrynews.com/mag/farming_...

http://www.123farmworks.com/trimble.htm