•utilize a shift up/idle back principle to save fuel, improve dozing cycle fuel efficiency and better match machine speed to application and ground conditions;
•automate blade and ripper controls to maintain optimal blade load, reduce track slip, protect the grade, and maintain peak productivity.
Advanced electronic controls also enable breakthrough powertrain technology, such as the electric drive available on Caterpillar’s D7E.
Simplified Operator Control
The role of the dozer operator continues to evolve. “The operator’s role has changed in terms of controlling various functions of the dozer,” says Peterson. “In most ways that work is much easier. Controls are more comfortable and ergonomic. Machine direction, speed, blade pitch and angle are now controlled with a simple joystick or thumb switch inputs. Advanced controls automate portions of the cycle, improving productivity and reducing operator fatigue.”
For example, electronically controlled drivetrains no longer require the operator to shift gears, or even use brakes. The drivetrain controller, combined with the engine controller, ensure the machine is adjusted perfectly. This takes the pressure off the operator to determine when it’s time to upshift or downshift. The operator can instead focus on the task at hand, with less mental and physical fatigue.
“The electronic technology that controls our dozers today is much more sophisticated, yet is meant to be seamless to the operator,” says Boebel. “Outside of simplified controls, owners and operators may not necessarily see the electronics that are improving their dozer’s performance. But they will notice that they aren’t filling it with fuel as often or get a job done faster than expected.”
Making Grade Control Possible
According to Peterson, powertrain integration and machine control and guidance technologies are the two areas that have had the most dramatic influence on dozer productivity and efficiency. “Machine control and guidance is another key area where electronics help us deliver more customer value,” he says.
The evolution from pilot to electrohydraulic controls has largely been driven by the desire to integrate automated grade control systems into the machines. Automated grade control enhances efficiency, reduces rework and enables even novice operators to achieve grade quickly.
The majority of today’s dozers are outfitted with some type of automatic grade control system, which controls blade functions. Several different types are available, ranging from 2D systems such as laser controls to 3D systems such as GPS or total stations. No matter which system is used, all have one thing in common: they improve the overall work efficiency by eliminating several of the steps required if preparing a site in a conventional way.
With automatic grade control, the final site design can be planned in the office and then loaded into the grade control system mounted on the machine. The system will then automatically control the blade to form the site. At the same time, it records the blade position. As a result, the final site design is controlled from the very start.
“Electrohydraulic controls enable grade control systems, which allow the dozer to automatically make adjustments accordingly,” says Gilbeck. “This has revolutionized the use of dozers — how efficient they are and how fast they can go.”
Such technology does take some of the decision making out of the operator’s hands. But no matter how much electronics and electrohydraulic controls have enhanced dozer performance, the operator remains a critical component to precise grading.
“Operators today are held to a higher standard,” says Boebel. “Customers are demanding the technology that makes their machines more productive. But they also recognize how important it is for operators to be integrally involved to maximize machine productivity and minimize input costs.” ET