Coordinated optimal control of the speed of shearer and scraper conveyor based on their energy consumption models

The synergy of “intelligentization + equipment” is one of the indispensable technologies to realize the intelligentization of fully mechanized coal mining.The shearer and scraper conveyor(abbreviated as SC)are the core equipment of fully mechanized mining, whose coordination determines the overall smartness, efficiency, and energy consumption in coal mining production.Based on the authors’ previous research on the shearer’s energy consumption model and the characteristics of bidirectional mining, the authors established the energy consumption model of the scraper conveyor considering the operation of the shearer through the analysis of the density and real-time coal flow as well as operational resistance on scraper conveyor during each mining process.In order to verify the validity of the established model, a realistic SC system of the 9105 mining face of a coal mine in Shanxi province was taken as a study case.The MATLAB simulation result of the variation trend of the scraper conveyor’s energy consumption, especially when the traction speed and the chain speed are at the reference or proportionally change in a certain range, is consistent with the practical experience.Simulations with 45 groups of speed coordination reveal insights into the impact of the three speeds on the energy consumption of the SC, and the path of the maximum decrease for the energy consumption through speed coordination can be derived.Furthermore, an optimal control method for coordinated traction speed, drum rotational speed, and chain speed based on the energy consumption models is proposed to minimize the total energy consumption in the bidirectional mining under various constraints such as production quantity, speed limits, mining time, etc.With the purpose of highlighting the superiorities of the proposed optimal control method, the optimized coordinated speeds and their corresponding energy consumptions are obtained through MATLAB simulation on the same 9105 mining face.The comparisons among the reference speeds, and the optimized ones demonstrate that the proposed coordinated optimal control reduces the total energy consumption up to 10.9% in a single production cycle, in which the energy consumption of the shearer and scraper conveyor are reduced by 4.47% and 11.71%, respectively.The results show that the proposed coordinated optimal control can effectively decrease the energy consumption of the SC.