The Guardbot system is able to be controlled remotely, by hand, or programmed to navigate through a GPS signal. In this way, the unit can be programmed for perimeter checking, as well as for complex moves within a larger area, such as an airport flight line. The Guardbot’s augmented reality user interface is highly intuitive and boosts operator alertness to ensure full control. Using the system's ground control station, a user has available a 2D/3D motion planning feature, as well as moving map displays.
Guardbot weighs approximately 57 pounds depending on its payload. It has a 22 degree climb capability, and can travel through snow, over sand and mud, and float or swim in water at nearly seven miles per hour without making a sound. Guardbot is battery operated and will run between eight and 16 hours per charge, depending on the mission profile and payload.
Guardbot attains its motion through the use of a patented drive-mechanism. Basically, the drive is produced using a motorized pendulum to propel the unit by changing its center of gravity. This allows it to easily provide forward and backward operation, as well as make 360-degree turns. The unit is designed for non-intrusive surveillance, providing inspection and identification. It accelerates and decelerates quickly and smoothly on land, while amphibious movement is consistent.
The Guardbot incorporates two dynamic DC brushless motors manufactured by Maxon Motor. The motors provide the 6.2 nm torque specifications needed for easy acceleration and deceleration of the Guardbot. Permissible torques run as high as 23 nm. For this application, motors are being operated from a 48V DC EaglePicher battery pack. Feedback control of the motors is used for accuracy.
According to Peter Muhlrad, president of American Unmanned Systems, “The motors are the most critical components of the Guardbot. That’s what allows it to move the way it does.” Each motor is also connected to a planetary gearhead and rotary encoder feedback system manufactured by Maxon.
Guardbot has been designed for a variety of highly sensitive applications including airfield and warehouse surveillance, aircraft inspection, laser and RF detection, and harbor and ship patrol. Many of these high-security operations are not well protected, using only stationary cameras. Dependent on the sensors used inside the Guardbot, it can also perform smoke and fire detection, hazmat/chemical detection, radiation detection, audio surveillance, and much more.
American Unmanned Systems is currently testing and evaluating an underwater version of the Guardbot. Other-sized models are also under test, including a half-sized model that’s 11 inches high, and a large unit over three yards high that will offer higher speeds and a more robust construction for higher payloads.
— Paul McGrath is Regional Applications Engineer for Maxon Precision Motors.