3 . through experiment using sensor and technique of dynamic measurement , the data of the pump pressure , pressure of upper and nether cavity of hydraulic vat and punching power has obtained synchronously . then exact figure and corresponding relation of these parameter also some relationship between these parameter is got by means of technology of signal processing during elevating , falling and pressure - retaining . 4 在液压打桩锤实验装置上利用传感器和动态测试技术得到油泵出口压力、液压缸上、下腔压力和桩锤下打力的同步实测数据，再利用信号处理技术分析上述参数在上升、下打和保压过程的精确值及对应关系，获取了液压系统动力学参数与打桩锤力学特性关系的设计知识。
Plc has small cubage , strong function , high reliability , ability to adapt abominable field environment of construct machine to face . in order to improve adaptive ability of hydraulic pile hammer to various soil , various finial velocity and dropping length must be obtained by adjusting time of lifting , dropping and keeping pressure that is accurately selected by the control system of plc Plc体积小、功能强、可靠性高、能适应建筑施工机械恶劣的野外环境。通过plc电控系统可以准确选择不同的上升、下降和保压时间，使得液压打桩锤具有不同的下打高度，从而获得不同的打击末速度，提高了液压打桩锤对不同土壤的适应能力。
