Energy efficiency of pressure shock damper in the hydraulic lifting and leveling module

This study evaluates the energy efficiency of pressure shock damping in a hydraulic lifting
and leveling (HLL) module of a mobile robotic bricklaying system (RBS). The HLL module includes
a servohydraulic actuator (SHA) and a hydraulic shock damper (HSD). The proposed adjustable
HSD consists of a hydraulic accumulator circuit (HAC) and proportional damping valve. The
frequency characteristics of the impedance and damping efficiency indices were used to evaluate
the effectiveness of HSD damping. The dynamic responses of the SHA with and without HSD were
analyzed based on a nonlinear state-space model. To control the damping of the pressure shock in
the SHA-HSD system, a linear quadratic Gaussian (LQG) controller that follows two measurement
signals was implemented. The LQG controller was adapted to the specific dynamic requirements
of the SHA-HSD control system and nature of the RBS shock loads. The effectiveness of the LQG
controller was evaluated during RBS operation under laboratory conditions. The main purpose
of this study was to dynamically stabilize a leveled robot base subjected to shock loading during
automatic operation of the RBS.