Locus control of a Knuckle Boom Crane for forestry machines

Abstract

In this report, a locus control system for a Knuckle Boom Crane is developed using the 3 dimensional Joy Stick as an input device. The Knuckle Boom Crane has 4 degrees of freedom, because of the Telescopic Cylinder; thus a restricted condition is needed for the locus control. In this control system, the length of the Telescopic Cylinder is in proportion to the distance from the base to the tip of the Knuckle Boom Crane. The system allows an operator to manage the Knuckle Boom Crane with only one Joy Stick instead of manipulating the several levers. As a result of the experimentation, this controller is able to keep the tip of the Crane within 20 mm from a target line. This accuracy is enough for forestry use. Because the amount of the hydraulic fluid is limited, this controller was a function to keep the velocity of movement less than the velocity of maximum flow. So this control system is not limited by the rack of hydraulic fluid, and makes the velocity larger.