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Utility of High Pressure Oil with Digital Proportional Values in Servo Applications



Richard J. Norcross


The Carderock Division of the Naval Surface Warfare Center is developing the Automated Paint Application, Containment, and Treatment System (APACTS). APACTS will apply anti-corrosive and anti-fouling paints to ship hulls in an environmentally sound manner. To provide accurate motion over very large surfaces, the APACTS motion system employs a self-propelled base carrying a long reach macro-manipulator, which in turn carries a quick response micromanipulator to maneuver the paint nozzle and containment device. The macro-manipulator is a commercial shooting boom aerial work platform (AWP). The AWP uses digital proportional hydraulic valves to control the oil flow to the actuators. The APACTS control system coordinates the flow to cause the macro-manipulator to move the micromanipulator along the ship's contours. The APACTS developer desires to operate the AWP's hydraulic system at higher then normal pressures. The added pressure generates the speeds and accelerations required by APACTS micro-manipulator to maintain nozzle trajectory relative to the surface. The experiments reported here indicate the servo performance of the standard digital proportional valves is retained with the increased oil feed pressures.
NIST Interagency/Internal Report (NISTIR) - 6896
Report Number


Aerial Work Platform, APACTS, Boomlift, Coordinated Control, Servo Control


Norcross, R. (2002), Utility of High Pressure Oil with Digital Proportional Values in Servo Applications, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed June 21, 2024)


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Created July 1, 2002, Updated December 3, 2008