【正文】 the following benefits are also enumerated: 1. Accurate selective mining of mineralized horizons2. Accurately finding the low wall batter line in coal stripping operations, thus reducing overdig, or lost coal3. Accurate representation of hazardous areas, such as loaded blast areas or areas underlain by old underground workings4. Creating more even benches, thus reducing truck cycle times and wear and tear on trucks and reducing dozer and grader time on benchesA case in point is the Collinsville Coal Mine, owned by Xstrata Coal and operated by Thiess Contractors in northern Queensland. Following the introduction of a guidance system, three pits containing million cubic meters of excavatordug overburden showed an average overdig of % and underdig of %. Overburden which was moved in 12 pits dug prior to the installation of GPS guidance amounted to million cubic meters and showed an average % of overdig and % of underdig. The reduction in overdig was sufficient to pay for the systems within a few months. Thiess subsequently installed guidance systems on the three other excavators at the site.The Role of High Precision GPS Machine Guidance in Mining (Seymour and Williams, 2022) GPS technology can now locate the bucket of a shovel or the blade of a dozer to within 50 mm. Other positive outes include precise selective mining, even when the ore is visually indistinguishable from waste。挖掘機工作裝置液壓系統(tǒng)屬于一種典型的工程機械復雜機電液系統(tǒng)，其機械結構參數(shù)的多變性，液壓系統(tǒng)的高度非線性，以及整個系統(tǒng)存在大量不確定量(不確定參數(shù)及不確定的非線性模型)，都使得液壓挖掘機工作裝置的運動控制成為一比較困難的工作。負載敏感系統(tǒng)是一個具有壓差反饋，在流量指令條件下實現(xiàn)泵對負載壓力隨動控制的閉環(huán)系統(tǒng)。當液壓泵的輸出流量不足時必須使各操作閥的輸出流量按比例地下降，即保持對各操作閥的操作量之間的比例(分流比)不變。 improve the mechanical operating performance, reduced vibration and noise, eliminate public hazards, better design and equipment cab. Hydraulic excavator control system is posed by the engine, hydraulic pumps, multivalve and actuator (hydraulic cylinders, hydraulic motors and other power system control system. Excavator hydraulic control system is flow control, negative flow control and load sensing systems the load sensing system for its energysaving, high efficiency and lifelong significant advantages to really develop in Europe in the 1980s, widely used in modern construction machinery. load sensing system is a pressure poor feedback, closedloop system in the flow of instruction under the conditions of pump load pressure servo control load sensing system according to the type of control can be divided into a pump controlled load sensing system and the valveregulated load sensing system。 bit in the system39。 The adjustment control of the electronic integrated hydraulic control unit is designed according to mon standards, their functions and specific tasks determined by the microprocessor control center and control. Usually microprocessor can store multiple sets of functions in the control scheme to adapt to the different structure and function o