Machine control has come a long way over the last 15 years in the UK. 15 years ago, machine control was only found on the largest of construction projects. Projects that lead the way in terms of innovation, testing the latest developments with the companies that were at the pinnacle of the construction industry.
Now, machine control can be found at a lot of sites throughout the UK and the world. Construction sites that now can benefit from the increased accuracy and time savings that come with using machine control.
But where did machine control start?
The History of Modern Machine Control.
Modern machine control in construction is considered to be when we started to use surveying equipment to give direct guidance to the machine and the machine operator. The earliest machine control was first seen in the mid to late 1990’s. Just as I started construction engineering, but I didn’t have any experience of machine control until 2007.
Take up of machine control has been slow and patchy throughout the UK. Although those who have been working with it will probably say different. As once you do start working with it. It is easy to see the advantages.
Whilst my first experience with machine control was in 2007 and 2008 not everyone I worked for/with were willing to take on board the cost or fitting of the systems to their machines. In 2009 I worked with a company that wouldn’t consider machine control and needed numerous engineers to set batter rails and profile boards. And they worked the engineers hard, and also had a high turnover due to the excessive workload required to keep all the machines working.
It wouldn’t be until midway through 2010 that I would be involved in machine control again.
The Early Fitment of Machine Control Systems.
The first machines that had machine control that I remember were dozers. The machine control systems were fitted to Dozers retrospectively. There was no ability to control the machine as there is nowadays.
This meant that these systems only provided the machine operator with guidance. The skill of the machine operator was to achieve the positions and levels given on the screen in the cab. No longer was the only way to achieve the right levels of a road or earthworks site down to the site team to bone in between two profiles and then to send the information (via site sign language) to the dozer driver.
The benefits of the machine control systems were clear even at this stage without any automation the machines themselves. The increased ability of the site teams to achieve the finished earthworks profiles accurately in layers paid big dividends in time saved.
It wasn’t long before surveying equipment manufacturers and construction equipment manufacturers teamed up to offer integrated solutions.
Machine Control – Integrated Solutions.
It was the early 2010’s that saw the start of collaboration between the heavy construction equipment manufacturers and the surveying equipment manufacturers.
Fitting the sensors, wiring and ancillaries to dozens, graders and excavators made a lot of sense at the time. This paved the way for the machines have a degree of automation. Letting the machine set the level of the blade or bucket once again paid dividends in time and therefore money or profit.
All good then you would think.
Yes, apart from the way the parties went about the collaboration. In their wisdom, they decided to team up with only one supplier.
Trimble and Caterpillar teamed up together, and Topcon and Komatsu teamed up together.
This left the site teams with a problem. Most construction site hire in their equipment for a particular project. And hiring equipment means that you don’t always get the brand of machine you request.
This meant that the site surveying or engineering team had to be adaptable. Often having to have different survey equipment and different survey software in order to make the machine control work.
To complicate the matter further for the site survey or engineering team there was also the matter of the different forms of machine control. By this I mean whether the machine was receiving its position signals via a GPS System or via a total station system. Each has its own pro’s and con’s.
This meant that often in the early 2010’s the site teams usually had to go with a single manufacturer for all their machine control solutions for the site. They had to choose early on to go with either Trimble, Topcon or possibly Leica.
Machine Control – Cross Communication.
It was in the early 2010’s that I remember being able to run different manufactures GPS systems with each other. Trimble were still trying to closely guard their systems from being used with other manufacturers. But Topcon were making it easier to cross communicate between systems.
Most sites in the UK have Trimble GPS Base Stations, and this is still true today. And they are nearly always set to their own communication protocol. I had a Topcon GPS Base and Rover kit and wanted to use the GPS rover off a Trimble Base Station. With the base station corrections being transmitted on a CMR+ Trim Talk format I could have corrections and accuracy from the GPS satellite system. If it was set to the RTCM3.0 Trim Talk format I could get the GPS and GLONASS satellite system corrections.
Knowing that this was possible, it then became easy to have Trimble, Topcon and Leica machine control systems running on a site from one single base station.
Machine Control – GPS Systems take over.
By 2015 nearly all the sites were using GPS Machine Control rather than the total station systems. I remember using the total station systems in 2010/2011 on the A1D2B project. Using them for controlling dozers and graders. We had to get in early to set them up in the morning so that the site team could be working from 7:30. But I think there were several reasons that over the course of the next few years using total stations for machine control died out.
But it wasn’t the early mornings that killed of the total station machine control. Total station have one advantage over GPS Machine control but that wasn’t enough for them to stay the course. Total stations are more accurate than GPS systems over smaller distances. But they need to have line of sight of a prism to work.
This means that the machine can only work towards the total station. If the total station looses sight of the prism then the machine doesn’t know where it is. It also must stay still until the total station is locked on to the prism again.
Then there is the effective range of the total station. Most total stations will have a working range of about 300m. After this the accuracy will decrease due to the angular error and the distance involved. Also, the range of the radio attached to total station is limited. This is due to the power of the radio on the total stations. The furthest range I have ever had with a total station radio is about 700m, and at this distance it wasn’t working all the time.
Another problem that affected total station machine control was issues when working close to the total station. Vibration from the machine control plant would affect the compensators inside the total station meaning that the accuracy of the work would suffer. You can see this affect if you look through a total station (or a level) when machines are passing.
Vibrations from the machine were also a problem for both the GPS Pods and the prisms mounted on the machine. The prisms had to be mounted securely and this meant that they were subject to constant shocks and vibrations. This meant the life span of the prisms were greatly reduced too.
This is also the case for the GPS Pods too. But this was solved by mounting these on springs to cushion the sensors from the shocks. To compensate for the movement of the these sensors, the rate at which these sensors work is 50Hz. Taking 50 reading every second compared to the one reading every second of the GPS rover units used by Site Engineers and Surveyors.
Machine Control – A Brief History.
So, by the 2020’s machine control had moved pretty much entirely to GPS Systems. The accuracy of the GPS systems has improved somewhat with the increased numbers of satellites that can now be tracked at any time of the day.
Now, not only is there the American GPS System, the Russian GLONASS system, the European Galileo System and the Chinese BeiDou system. Four main satellite systems for navigation purposes alone. That surveyors and engineers have harnessed, increased the accuracy and put to use to control machines on construction projects.
There are just three main companies providing the kit that enables machine control to be possible, they are Trimble, Leica and Topcon.
I wonder where machine control will be in another ten years.