GPS Blade Control

[WILDCAT]

Just recently I have been working on a large project where they have used the GPS blade control on dozers and GPS control on Excavators. The GPS systems do have merit, but some days the system would drop out from lack of satellite coverage. The job is based in Australia (southern hemisphere). Does this problem occure in the northern hemisphere over America?
Which system is most popular in America -Topcon GPS system or Caterpillars Trimble system?

Regards,
WILDCAT

 

[pushcat]

I use a Trimble system. I do occasionally lose enough satellites so that I'm not able to use the automatics. Usually still have enough reception so I can do it manually, just lose the .05' accuracy. Just rough it in untill they come back in and then finish it. Strangely enough, it varies from job to job but often it happens around the same time on each particular job so that you can predict and plan ahead work you can do in the downtime.

 

[Turbo21835]

Yes it happens here too. As pushcat said, when you lose your satellites you loose your .05 accuracy. Depending if your doing the final grade or not, there are some tricks to get around that. There is a way in your in cab monitor that allows you to use different settings for automatic work. Most have it set on high accuracy. You can knock it down to medium accuracy and still use the auto feature. I dont use the automatic feature very much, depends on what im working on. I feel I can get a better grade by hand. This seems to hold true in slopes. Maybe its just the way the engineer has inputed the information into the system. The gps wants to leave defined lines and lips in a slope. It just doesnt work that way in the field. I pull most of those grades by hand. Funny that you mention that you can predict downtime. Most jobsites it is 12-1:30. Our crew would take lunch when we lose gps, since the big dozer and finish dozer wouldnt be able to do much.

 

[petersfamilytru]

Cost for Trimble???

What is the cost, per piece of equipment, for a full GPS package? I'm not sure if my dozer (Cat D6D is able to use the blade control, but it would be really nice if I could do everything else. I currently run a laser on the blade of my cat and on my scraper, but GPS would really help.

Just wondering if a little guy like me can afford such sophisticated attachments.

 

[WILDCAT]

Thankyou pushcat, Turbo21835 & petersfamilytru for your replies,
3 months ago, the client that I work for wanted all of thier subbies to run topcon systems in thier machines. They wanted to move away from grade pegs and all machines on site would have 3D screens to work the job. Originally the talk was for me to have a topcon mm system fitted to my grader. Before I was formerly asked to do that, we were using hand held rover systems. We experienced problems. One thing I will say, is a grade peg does not suffer from poor satellite coverage, flat batteries or problems with extreme cloud cover. The thing a grade peg can suffer from is any machine running it over. The cost of having a mm system fitted to a machine is considerable.

Regards,
WILDCAT

 

[pushcat]

When we got our GPS setup 5 or 6 years ago the cost for the total package on a new dozer would have been around $400,000. But we had a super low-houred D6M to put it on instead of a having to buy a new machine. Back then a new dozer was running around $225,000. I don't know exact cost these days but expect to drop at least $100,000 to get started.

As for slopes, that's the best part with using GPS. It works great on a straight slope until you get to a corner, like in a lagoon. Usually have to work the corners manually because of the design in the flash card has too many different angles too close together. I usually run off 2 points custom on the blade and set it to not undercut. Hard to explain without actually looking at the screen in the dozer

 

[JDOFMEMI]

The price tag is up there. I run all Trimble, and the last machine I set up was a 14G, and it was about 75K for the full automatics. Dozers are around the same, maybe a little more due to the larger valves needed for bigger machines.
Then to get it all to work, you need a base station for about 30K, and prefferably a hand held, or "Rover", for another 25K or so. This is just ballpark pricing, many variables.

They have some drawbacks, as have been posted, but the production is so great that even if it was sown 2 hrs a day, you will still double the finish product over the conventional way. And its rarely down more than 1/2 hr a day or so.
You do need a lot of work lined up to get the use out of it in order to justify the price, but it will definatley pay for itself.

 

[Dieselfixer]

Having a GPS system installed on a Cat 120H motor grader tomorrow. Price of the unit with installation is $32,000.00

 

[RT Engineering]

I am intrested in a GPS system. Still trying to decide between Topcon, Trimble, Leica, or brand X . They are all expensive, and I believe it will stay that way for a while. Does any one have any good, or bad things about these or any other systems?

One problem I have found with the Trimble system is that the machine control GPS is a completely different system from their surveying GPS system. So I would need to buy two complete expensive systems. I should have my PLS license next year, and would like to use the equipment for both machine control and land surveying.

How are you creating the 3D models? What is involved in changing the model when a 'Bust' is found in the field?

Is anyone using a remote network instead of a fixed base station? Good results?

Thanks,

RT

 

[petersfamilytru]

OUCH!!! It looks like Peters Family Trucking is going to be using the trusty old laser's for quite some time. I don't think I'll be installing $100,000 worth of equipment on a $60,000 Cat anytime soon.

Thanks for the information!

www.petersfamilytrucking.com

 

[pushcat]

We use our Trimble system for both survey and machine control. I don't understand when you say you need two seperate systems, it uses the same base, you just have to buy the rover and supporting software, but that all came with the package we bought anyway. We used to have engineers and surveyors draw our designs for us, but lately we have been doing it ourselves. It's not that difficult once you get on to it.

 

[WILDCAT]

G'day Dieselfixer,

For that price that you mentioned ($32,000) was that the total system up and operational or was it just what they call hard wiring the machine?

Regards,

WILDCAT

 

[Dieselfixer]

Hi Wildcat
That price is for the total up and running system.

 

[roddyo]

This would make an Exellent Category

I love this forum. It would be even better if there was a category dedicated to lasers and GPS systems. That would put all these questions and answers at one place. Any way you look at it Laser and GPS is the wave of the future. Just my 2 cents.:ban

 

[D6c10K]

Wildcat,
We do land surveying and ocassionally set up job control for GPS guided equipment. This usually consists of setting a few control points surrounding the job. (set with EDM or GPS and leveled for elevation) They usually set a 4x4 post somewhere near the center of the job to mount their GPS base on and then localize it using our control points.

Most areas here either have GPS networks in place or are in the process of building them so using a GPS base is becoming much less necessary, although that may not be an option in your area. You use a cellular signal to log into the network that is already tranmitting GPS correction data....no more base. Localization at the job site would still normally be required.

As far as dead times for satellites...in my area there is an hour or two mid-day that has been a problem in the past when you could only get 4 or 5 satellites. Since we started using a receiver (ours is Topcon) that uses both GPS and Russian Glonass satellites that reduced coverage problems to a minimum and we often are tracking 8-12 signals. The European Galileo network is in process of being built which will add even more. If I were buying a system I'd make sure it was capable of tracking all three constellations, or at least be able to be upgraded to all three when the Europeans come on line.

With all that said, you're still going to loose lock ocassionally for no obvious reason, which can be frustrating, and of course trees and buildings always cause problems.

As far as the machine controls/software themselves, I don't have experience with them so I can't give opions there. Of course someone is going to have to produce the DTM (digital terrain model) for the site, typically the engineering company that did the design.

If you're not familiar with GPS, I'd spend some time learning or find someone to help you evaluate both the hardware and software so you're sure it has the features you need.

 

[Countryboy]

Welcome to Heavy Equipment Forums D6c10K! :drinkup

 

[morgsD6r]

RT Engineering we use Topcon, Trimble, Leica, and brand X at work. leica seems to stuff up the most with signal and program upload topcon is the easyest to use and stuffs up the least.

 

[Countryboy]

Welcome to Heavy Equipment Forums morgsD6r! :drinkup

 

[grunk36]

accugrade/trimble is the best

for the last 1.5 year i have been driving a D6R series 3 with the cat accugade on its the most fantastic system the more i use it the more advanced it gets you can say it grows together with the operator i have got glonass/gps receivers ms 990 and glonass/gps base station and never ever loose the signal not yet anyway