Preliminary Experimental Research on the Influence of Counterbalance Valves on the Operation of a Heavy Hydraulic Manipulator during Long-Range Straight-Line Movement

Abstract

The effective use of robotic manipulators is particularly important when carrying out hazardous tasks. Often, for this type of mission, manipulators equipped with a hydraulic drive system are used, and their work results primarily from the implementation of precise movements through their effectors. In heavy manipulators, limiting the uncontrolled movement resulting from high inertia and relatively low stiffness has an impact on the improvement of the control precision. Therefore, the paper presents experimental studies that allow the assessment of the impact of the use of counterbalance valves on the precision and dynamics of a manipulator with a hydrostatic drive system. The tests were carried out for a wide range of effector velocities along a horizontal trajectory, on the basis of which, it was found that it was possible to improve the precision and dynamics of the work of such manipulators due to the precision of the trajectory and pressures in the drive system.

The Influence of the Operator’s Perception on the Energy Demand for a Hydraulic Manipulator with a Large Working Area

“…Due to the typical ranges of manipulators with a large working area [1,11,21,33,34], the tests were carried out for three ranges L (6 m, 3 m, and 1.5 m), corresponding to the size ratio K of ×10, ×5, and ×2.5. The maximum marker spacing (effector movement range) was 8 m, 4 m, and 2 m, respectively.…”

“…The second group is teleoperated manipulators that work in unknown and less structured environments, and their tasks are not predefined [14,15]. Due to the wide scope of their application [16][17][18][19][20][21][22][23][24][25], they are characterized by a large working area (larger than the operator's arm reach) and a hydraulic drive system, and their control method (e.g., direct or coordinated teleoperation) allows for the transfer of manipulation skills from humans to manipulators.…”

Experimental Research on the Influence of Size Ratio on the Effector Movement of the Manipulator with a Large Working Area

“…The research was conducted for distances 2, 4, and 8 m, which gave size ratio K = 2.5; K = 5 and K = 10. These are typical size ratios during positional control for manipulators with a large working area [23,24,31,[40][41][42][43]. Each subject moved, using his hand, the laser spot (effector) displayed on the screen from point A to B (right to left) and back from B to A (left to right) in a straight line.…”

“…The research was conducted for distances 2, 4, and 8 m, which gave size ratio K = 2.5; K = 5 and K = 10. These are typical size ratios during positional control for manipulators with a large working area [23,24,31,[40][41][42][43].…”

“…The use of this type of control is particularly desirable and important if an inexperienced operator controls the manipulator. Thanks to this, operators are able to achieve high control efficiency comparable to experienced operators in a relatively short time [22][23][24].…”