Improved User Interface Controls Enabled for Excavators and Other Earthmoving Equipment

Achievement date: 

A single, ergonomically supported joystick control for earthmoving equipment has been tested at the NSF-funded Engineering Research Center (ERC) for Compact and Efficient Fluid Power (CCEFP), headquartered at the University of Minnesota. The control relies on natural intuitive motions to both increase productivity and ease operator fatigue. 


Joystick controls have been used for decades to operate excavators, backhoes, and other types of earthmoving equipment. However, when using a joystick, the equipment’s swing, arm, stick, and bucket motions are not intuitively coupled to the operator’s joystick motions. In natural motion user interface controls, the equipment’s motion can be kinematically mirrored with the operator’s physical movement. These more intuitive controls alleviate the physical and cognitive burdens on human operators that can result from long-term use of joystick controls, thereby improving overall human-machine task efficiency.


With current earthmoving equipment controls, each standard electronic joystick affords two motions or degrees of freedom. Each joystick motion controls one axis of motion or function; hence two functions are controlled with each joystick. “Natural” motions can be achieved with a single device that has been shown to remove 85 percent more soil than the two-joystick interface when operated for short periods in tests on an excavator simulator. But when tested, this initial arrangement was still tiring to the operator because the weight of his arm did not have support during operation. Additionally, releasing the grip would cause the device to drop under its own weight.

Consequently, a search for new configurations was launched, with emphasis on achieving both natural correspondence and ergonomic arm support. A “kinematically similar” design emerged, which offers motion in the vertical plane and swing control by a separate joystick. This interface design proved to move 50 percent more soil than two joysticks, but continued to lack ergonomic support. By changing the motion to a horizontal plane, the operator’s learning time was not significantly affected and his or her arm could now be well supported. Tests concluded that on longer duration runs, using this natural motion control the operator did not fatigue and still moved 35 percent more soil than was possible on a similar run using two joysticks for control.