Doosan Infracore North America has added an electronically controlled excavator model with machine-assisted technologies to its next generation of crawler excavators in the United States.
The fully electro-hydraulic control system on the DX225LC-7X crawler excavator enables advanced machine guidance and machine control systems. This includes a 2D and upgradable 3D grading system.
The DX225LC-7X is part of the company’s excavator plans for 2022 and 2023 as it replaces Doosan-5 models. The Doosan -7 Series crawler excavators, including the standard DX225LC-7, feature higher digging forces and lifting capacities and increased fuel efficiency. Diesel engines in the excavators will continue to meet Tier 4 Final emissions standards without diesel particulate filters.
The larger models will come with D-ECOPower for saving fuel. Models now available for dealers to order include the reduced-tailswing 14-metric-ton DX140LCR-7, the DX225LC-7, the DX255LC-7 and the DX350LC-7.
“Doosan continues to build on the success of its existing excavator platform with more machine features that help our customers improve their productivity,” says Joel Escalante, product specialist. “We’ve enhanced the excavator cab with additional comfort features and now offer an all-around view monitor for even better operator visibility of the jobsite.”
Upgrades to the standard machines are an improvement in efficiency and productivity from previous models. However, he suggests the DX225LC-7X takes control to another level.
“The reason we put the DX225LC-7X as a different machine is because the DX225LC-7X has a fully electro-hydraulic system,” Escalante says. “What that means is the controls, your joysticks, have no pilot hoses; it's all electronic.”
The technology on the machine includes programmable joystick switches for ease of operation, a fully electronic joystick, a rotary sensor and equipment sensors on the boom, arm, bucket and upper body of the DX225LC-7X, including a laser catcher. This system allows the excavator to provide supplementary assistance with precision functions and tasks and results in greater productivity and efficiency. For the operator, the joystick and pedals are fully electric, but give the operator the same feeling as the regular hydraulic joysticks.
“The difference is that on the standard machines you have pilot hoses sending the signal for a specific function they're doing to control the bucket the arm, boom, etc.; whereas, on the -7x system, it's all electrical, and the computer is telling the pilot system and the main control valve what to do the moment the operator starts functioning the joysticks,” he says.
For now, the DX225LC-7X is the only Doosan -7 series model to have this option. With the 22.5-metric-ton machines being one of Doosan’s top sellers worldwide, it made sense for it to be the first model with the electronic controls. Escalante says the company is developing the technology on other models.
Escalante says Doosan recently had the DX225LC-7X at its demo center, and customers were fascinated by how easy it was to operate.
"The guys love the way how fast they can set it,” he says. “It is a very user-friendly system."
Despite being a technological advancement for the Doosan excavators, the controls are a lot easier.
“You don't need a very skilled operator as long as they understand how to set the system,” Escalante says. He recalled a recent customer, a father, a very skilled operator, and his son, a young operator, were trying out the new machine. The son did better than his father because he knew how to play video games and understood the new system.
“The design behind it is to help the operator be faster while still remaining comfortable and also be more efficient and optimize the machine performance and efficiency,” Escalante says.
“This system allows a better integration of the 2D and 3D machine guidance and machine control systems with grade assist and slope setting,” Escalante says. Customers can dictate which system to put on their machines. Doosan integrates Topcon, Trimble or Leica or whatever system the customer works with. Cost is reduced for the customers to integrate with whatever system is on their fleet.
“The difference with the DX225LC-7X is that when you activate the grading system, the touchscreen allows you to set the assist mode, which allows the computer to help the operator,” he says. “All the operators must do is pull the arm function, and the machine controls the bucket and boom automatically to maintain the grading or slope. It's much more precise.”
Feedback to the operator is provided through audio and visual displays, including a new 8-inch Smart Touch screen, that are common in the Doosan -7 series. Escalante says the monitor gives operators improved control for intended or designed direction of travel and more precise control of setting bucket-tooth depth, height and slope.
“Normally when they’re trenching for a sewer system or water piping, it has to have a gradient,” he says. “When they trench this gradient, the slope has to be maintained from 100 yards, 300 yards or much more. With the 3D systems, they set the slope, and the operator just maintains the slope by looking at the screen.”
On the left side of the monitor is a column of color that changes as the depth gets closer to the set level. “When you're getting close, it goes from orange to green, and the operator knows through the corner of his eye because his eye is on the bucket at all times,” Escalante says. The alarm can also be set to beep to alert the proximity of the proper slope and depth.
Escalante notes that operators can set different parameters for different styles of buckets and just activate that bucket when he switches with a quick coupler. When the DX225LC-7X is delivered to the customer, all the sensors are already calibrated. The buckets the customer uses need to be calibrated, and no specific tools are needed. The system will ask the operator to enter the required measurements to finalize the calibration process, with around an hour needed to calibrate three buckets.
Also, if the job site is using a laser to maintain the depth, the machine has a laser receiver, so the operator doesn’t have to reset the depth every time the machine is moved. “It displays an icon right on the monitor so he knows that he can just continue digging with the same parameters,” Escalante says.
In addition to grading, operators can set a virtual wall to determine placement of surrounding obstacles.
“If the operator has obstacles on either side, he can set the limits, so the machine won't swing past that,” Escalante says. The function can be overridden at any time if needed.
The machine also has a weigh and lift assist function to measure and display the current weight of the bucket as materials are being loaded, to warn the operator when the total loading weight is exceeded. Escalante says the sensors are within 3% accuracy to give customers an idea of how much material is being moved with the machine.
The Doosan -7 series excavators enable operators to adjust power modes while using attachments. The four power modes are power plus, power, standard and economy. Work modes are digging and lifting, and two work modes for attachments: one-way and two-way flow.
The two-way flow is for using high-flow attachments. In that mode, power priority is given to the attachment rather than the boom and arm. Operators will also be able to tailor the excavator’s power mode when using attachments.
Escalante says the power plus mode is designed for severe digging conditions and massive truck loading to move a lot of material.
“Then we have power mode; it's one level below the power plus, and it's for extremely deep trenching and truck loading,” Escalante says.
For general trench digging or pipe laying, there is standard mode. Further, Escalante says, economy mode is ideal for more precise grading to maximize control and efficiency.
“For new operators, I always tell them use a standard load because the machine is not so fast and so demanding,” he says. “What happens is if you go right to power plus, the machine is going to do what you ask. And what happens is here in North America, the operators have the tendency to go full throttle, and then it's all brain and muscle versus computer, and we know who wins that battle.” Despite the power and speed increase, the operator ends up being less sufficient and wastes time because he can’t keep up with the machine. “Every time I'm in a jobsite, I see this problem,” Escalante says.
On each of the Doosan-7 series, there is an optional 360-degree all-around view monitoring (AVM) camera system that displays a full view of the machine’s surroundings. The AVM system pairs with the optional ultrasonic sensors, providing a bird’s eye view of the jobsite and a beeping alarm if the machine gets too close to an obstacle.
“It won't stop him from hitting anything, but this alarm helps the operator concentrate much better on the attachment because the alarm will tell me when the rear is getting too close to a wall or some other obstacle,” Escalante says. The beeping gets louder as the machine gets closer to an object. The ultrasonic sensors are only available on the standard machines and not the short-radius models.
Doosan also added a new fine-swing mode on the Doosan-7 series in which the operator can turn off the rotation, or slew, brake to prevent material loss from the bucket, especially when lifting. Fine swing, which can be engaged or disengaged manually, gives operators more control.
One option that Escalante says he really supports operators using is the boom float function. “If you don't have the -7x by having a boom float on the machine, the operator can be very fast and shorten cycle times in all applications,” he says. Currently the boom float is an option, but Escalante would like to see it become a standard feature.
Doosan -7 Series quick specs
- Horsepower: 115 hp (86 kW) at 2,000 rpm
- Operating weight: 33,800 lbs. (15,400 kg)
- Maximum digging depth: 19 ft. 8 in. (6 m)
- Maximum digging reach (ground): 28 ft. (8.5 m)
- Maximum loading height: 23 ft. 3 in. (7.1 m)
DX225LC-7 and DX225LC-7X
- Horsepower: 174 hp (129 kW) at 1,800 rpm
- Operating weight: 52,600 lbs. (23,900 kg)
- Maximum digging depth: 21 ft. 7 in. (6.6 m)
- Maximum digging reach (ground): 31 ft. 10 in. (9.7 m)
- Maximum loading height: 22 ft. 5 in. (6.8 m)
- Horsepower: 189 hp (141 kW) at 1,900 rpm
- Operating weight: 59,300 lbs. (26,900 kg)
- Maximum digging depth: 22 ft. 4 in. (6.8 m)*
- Maximum digging reach (ground): 32 ft. 10 in. (10 m)
- Maximum loading height: 23 ft. 1 in. (7 m)
- Horsepower: 285 hp (213 kW) at 1,800 rpm
- Operating weight: 81,791 lbs. (37,100 kg)
- Maximum digging depth: 24 ft. 8 in. (7.5 m)
- Maximum digging reach (ground): 35 ft. 11 in. (11 m)
- Maximum loading height: 23 ft. 6 in. (7.2 m)