Research status and development trend of hydraulic support precision pushing and fast follow-up technology

The hydraulic support precise pushing and fast follow-up is the key technical support to realize intelligent mining of working face. In order to realize intelligent mining, the precise pushing of hydraulic support is equivalent to the precise position control of valve-controlled cylinder system in coal mine environment, and fast follow-up of hydraulic support need to be realized through follow-up process, liquid supply with stable pressure, fast support movement, etc. Aiming at the precise advancing technology of hydraulic support, it is pointed out that the mature precise position control technology of valve control in related fields can be used for reference. This paper summarizes the research achievements of the electro-hydraulic proportional valve, high-speed on-off valve and electromagnetic directional valve control cylinder position control technology. This paper also summarizes the problems existing in the application of above achievements in the field of coal mines. It is proposed that the precise pushing of hydraulic support can be realized by developing large-flow high-pressure water-based electro-hydraulic proportional valve suitable for the underground environment and developing the intelligent optimization control algorithm. Aiming at the fast follow-up technology of hydraulic support, it is pointed out that the current automatic follow-up of hydraulic support is slow due to unreasonable follow-up process, unstable liquid supply system, and unreasonable support moving process. It is easy to appear the situation of not moving in place and losing support. The related research achievements of improving the follow-up speed are summarized from three aspects: optimizing the follow-up process, supplying liquid with stable pressure, and fast pushing support. The following points are pointed out. At present, the follow-up process cannot be dynamically adjusted according to the speed of the shearer, and the automatic follow-up based on equipment perception is still at the theoretical stage. Optimizing the structure and control algorithm of the liquid supply system is the main way to realize the liquid supply with stable pressure in the working face. But it can not effectively solve the problem of pressure and flow stability at the end of the hydraulic support when the multi-support cooperates. Improving the structure of the hydraulic system is the main way to achieve fast support pushing. But there are some problems such as the large pressure drop when high-pressure oil is transmitted over a long distance, the pipe explosion at the high-pressure point, and the difficulty of pipeline layout caused by increasing the pipe diameter. In view of the above problems, it is proposed to realize the precise pushing and fast follow-up of hydraulic support from four aspects: the constant pressure control of the working face liquid supply system, the improvement of the control precision of hydraulic support pushing, the guarantee of the automatic follow-up effect of hydraulic support, and the improvement of the whole follow-up speed of the working face. It is pointed out that the development trends of precise pushing and fast follow-up technology of the hydraulic support are centralized-distributed agile and efficient liquid supply, improvement of the edge computing capacity of hydraulic support controller, enhancement of adaptability of follow-up control strategy to stope environment, dynamic coupling and follow-up control of stope and equipment.hancement of adaptability of follow-up control strategy to stope environment, dynamic coupling and follow-up control of stope and equipment.