2003 Volume 34 Issue 6 Pages 134-140
The piling ability of a hydraulic vibro-hammering machine in construction work depends on the dynamic characteristics of the ground. A simulator which can realize these dynamic characteristics, i.e. the mechanical impedance, of various types of ground is required for the performance test of the machine. An electro-hydraulic servo mechanism is applied in order to construct the simulator to realize the equivalent reaction force of the ground. The amplitude and the phase of sinusoidal input signal of the servo amplifier of the simulator are adjusted iteratively to coincide the mechanical impedance with the desired impedance using a fuzzy reasoning method. The aim of this research is to find the optimal adjustment law of the input signal so that the number of iterations can be reduced. Experimental results show the simulator performs well enough for practical use.
