Scholar-researcher Randolph Renyu Wu working with the Office of Safety and Traffic Operations R&D Advanced Research Team, recently developed a new robotic trunk design to be used in highway maintenance. The design provides a very good flexible arm which functions somewhat like the body of a snake or an elephant's trunk. This robotic trunk could be mounted on a truck elevator and serve as a platform for a detector or a paint sprayer with shields to protect the environment from being polluted by the lead paint and blast debris. It could remotely inspect bridge paint condition and the physical state of bridge members, recover stripping media and paint with increased efficiency, and reduce the manpower and time required to strip and paint an overpass.

The robotic system will be able to work over a bridge or under a bridge for automatic routine inspection and other chores. This system could also be used for underwater inspection of bridges using dive servo-motors as the illustration shows.

The robotic trunk is perfectly flexible; it can be bent in such a way that it can even perform manipulations behind an obstacle (obstruction) or in spaces otherwise difficult to reach. The robotic trunk is formed by several elements, each element having a rigid tube inside and supported on the globular hinge of the element below. The rigid tube acts as human bone, and the cables are like human muscles. A special fan-wormwheel mechanism is designed for the trunk unit to pull and loosen cables. This mechanism can reduce the number of motors by one half, ensures the execution of the robotic trunk, and simplifies the control system. The principal advantages of this robotic trunk are perfect flexibility and low cost.

- James A. Wentworth