How to select 2D or 3D grade control systems for your crawler excavator
By Ryan Johnson
An excavator grade control system can increase your productivity, reduce your material expenses and create a safer job site.
Grade control systems for use with excavators are not new. You may already have some experience with these accessories on your machines.
Excavator operators can work more efficiently with some technology help from a grade control system. They will know they are delivering a product to grade to match a design file provided to them.
“Among the most common applications for these systems with excavators is digging a utility trench at a uniform grade over short distances,” said Aaron Kleingartner, dealer and product marketing manager for Doosan Infracore North America, LLC.
“They are also beneficial for excavating footings and producing a finished slope. With a system installed on the excavator, the operator can accurately dig, place a pipe and add fill material.”
Some construction firms can eliminate the need for an employee to check the grade. This frees them up to do other work, while the excavator operator maintains an accurate grade. And it can be safer to have fewer employees working outside of equipment on a jobsite.
“Another system benefit is avoiding overdigging,” Kleingartner said. “When this happens, you’re required to add material back in your trench. That means adding more Class 5 base material before the footing can be done.”
2D or 3D?
You can choose between two grade control systems — 2D or 3D — depending on the type of work that you’re doing.
Two-dimensional (2D) grade control systems allow excavator operators to work off a single plane — either flat, single or dual-slope. Operators know the grade is correct from point A to point B to dig a straight-line trench. They can expect a consistent grade on a vertical plane.
Three-dimensional (3D) grade control systems allow operators to add variable distances, such as a curved line or a curved trench. The excavator can be moved on the jobsite and still dig on grade. The 3D guidance system is especially beneficial for operators working on complex designs, like larger-scale drainage projects.
Construction firms can choose from several tech companies that have developed the technology for grade control. One of these companies is Trimble. Its GC900 Grade Control System is available for excavators and can be particularly useful in the 25 to 35 tonne excavator size class, based on the type of work these machines perform on a regular basis.
“Once a customer decides to add a grade control system to an excavator, the customer will work with a local dealer and a technology expert from the company that developed the system,” Kleingartner said. “They can help the customer properly install the components on the excavator, provide training and ensure it’s working correctly before they transport their machine to the job site.”
Components of grade control systems include:
- Two receivers (masts) situated on the back of the excavator above the counterweight.
- Mainframe sensor.
- Boom tilt sensor.
- Arm tilt sensor.
- Bucket link sensor.
- An optional angle tilt sensor.
- In-cab monitor.
Once installed, these components are likely to stay on that machine for the machine’s useful life. In addition, a monitor is installed in the excavator cab that provides vital information to the operator.
“Grade control systems use information gathered from global navigation satellite systems (GNSS), GPS, laser, sonic or total station technology,” Kleingartner said. “These information sources help excavator operators accurately position the excavator bucket in real time as the bucket, boom and arm move.”
Once the system is installed on an excavator, operators have a wealth of information available to increase their proficiency. The system provides real-time information to operators to ensure the project is completed correctly.
“Your operators are still in control of the excavator,” Kleingartner said. “Using the second monitor installed in the cab, your operator can see the location of the bucket and the programmed dig depth requirements. The system gives an indication of how far above or below grade you’re working, based on the tip of the bucket.”
Fleet managers can remotely monitor the excavator operator and the machine’s grade control system. Some grade control system manufacturers provide their customers with website access, making this information available to remote fleet managers or owners who are not at the job site.
Autonomous is the future
Although some grade control systems today allow an extra benefit that controls the work, it is still routinely left up to the operator to properly follow the programmed coordinates.
“What’s coming within the next five years is more machine automation,” Kleingartner said.
Some heavy construction equipment manufacturers, including Doosan Infracore, are already developing this technology.
“Doosan showcased its Concept-X technology at a live event at its proving grounds in South Korea in November 2019,” Kleingartner said. “Viewers saw excavators, wheel loaders and articulated dump trucks working autonomously. Using a site mapping drone overhead, instructions were provided wirelessly from an on-site workstation to the excavator.”
Until this sought-after autonomous jobsite is available, construction firms can still benefit immediately from adding a 2D or 3D grade control system to their excavators. They should contact their local equipment dealer to inquire about a system for their machine.