Study On The Key Technologies Of Self-adaptive Cutting For Shearer

Shearer is the key electromechanical equipment of mechanized coalface, and shearer automatic cutting is the essential condition to realize"automation"and"less humanizing"of mechanized coalface. Coal science and Technology in china's the eleventh five-year plan pointed out explicitly that"shearer memory cutting and adaptive control technology is an important content in the future". However, at present shearer used by coal mine enterprise of our country still controlled by hand, the primary cause of which is that coal mining machine's automaticity is low, and does not have the auto-adapted cutting function. So it is necessary to study automation control of shearer, which will realize automation, information and fewer human, and provide technical support for safety, high yield, and high efficiency of production in coal mine. This paper took research and development of electric traction shearer automation control system as purpose and proposed shearer's self-adaptive cutting method based on memory cutting and cutting load analysis on the basis of analyzing research work experience and existing problems before. We take cutting load of shearer as control goal, traction speed adjustment as major control mean and rocker height adjustment as minor mean to realize auto-adapted automatic cutting of shearer. This article researched deeply auto-adapted cutting system's body position, cutting path memory, cutting path tracking as well as cutting load dynamic examination for key technologies, and the main achievement included:(1) This article established three-dimensional coordinate system of the mining coal working surface, fixed the body location and posture of shearer with sensing information fusion of shearer, hydraulic support, the scraper chain conveyor, built theoretical model of position localization and the posture localization and infered the formula.(2) This article researched memory point selection, memory point data compression method and memory point data construction in the cutting path memory process, established memory points aggregate that take conventional point as the path curve body, key point as control command main body, feature point as the condition unusual main body, and encapsulated memory data with the model of artificial immunization, removed centralized distorted part of memory data with improved negative selection algorithm.(3) This text analysed and studied the track object, track strategy and track effect in the shearer's cutting path track process, proposed path tracking object based on erroneous belt on the base of analysing the existent question in the multinomial interpolation and the spline curve interpolation, proposed path tracking strategy based on conventional memory point, movement tracking strategy based on key memory point, and condition revision strategy based on feature memory point, and established the cutting path track evaluation model with the grey relational grade theory.(4) On basis of analyzing the merit and demerit of shearer cutting loading detection method this article proposed shearer cutting load examination plan based on the cutting motor electric current spectrum, established theoretical model about the cutting loading and the cutting electric current, and decomposed and restructured cutting electric current signal obtained from experiment with wavelet analysis theory. The experiment result indicated that the cutting electric current signal lags behind cutting loading in the time domain, but in frequency domain exists strong corresponding relationships. We established the"rotational speed-loading-electric current"model with artificial neural network and trained neural network model through experiment data got from industrial site motor loading speed-governing experiment, and obtained neural network model figure about relationships among the three.The laboratory experiments, factory experiments and coal mine working surface experiments indicated the body positioning scheme could gain the position and the posture information of shearer accurately, when the seam inclination reaches 15°the position error did not surpass 1.4%. The cutting path memory scheme can record the path information, the control command information and the device status information of shearer with smaller data storage. In the actual production process track absolute error of cutting path is smaller than 0.06m, the grey relational grade between tracking path and tracking object is bigger than 0.9. The cutting loading analysis method based on cutting motor electric current can detect actual cutting loading in the shearer working process, on the basis of which the traction speed and drum height adjust themselves.