Underground Loaders Intelligent Shift Strategy Research

Scraper is a kind of equipment specially designed for the underground trackless mining operations, which combines shoveling, shipping and discharging in it. Its body is short and hinged in central. Currently, its transmission system is constituted of hydraulic mechanical transmission with torque converter. As it is known to all, the torque converter's efficiency is low (usually from 50% to 85%), the underground work environment is severe and the work condition changes frequently. In order to improve the work efficiency and the dynamic performance of the Scraper, it is necessary to shift frequently. But frequent operations of shifting would increase the labor intensity and cause the problem of not shifting in time. In order to improve the efficiency of operations and reduce the labor intensity, it is necessary to adopt automatic transmission technology in Scraper. This paper takes a certain type of underground diesel loader as research object. The main content includes:1 The work characteristics of the various components of the hydraulic transmission system have been systematically analyzed. Based on this, the mathematical model of components of the underground loader hydraulic transmission system was established. Aiming at the present disadvantages of non-leading of the engine's speed regulation mathematical model, a continuous differentiable dynamic mathematical model of the engine was introduced. And all kinds of resistance force underground in the process of working and moving was analyzed and calculated, then the dynamic equations of hydraulic mechanical transmission system was deduced.2 The basic theory of matching calculations of hydraulic transmission system of Scraper was systematically introduced, and the matching calculation of a certain type of Scraper was done. From the view of energy saving, two intelligent shift laws have been proposed based on a more in-depth study of energy shift law of Scraper. One took the speed of the engine and the speed of the vehicle as controlling parameters, and another one took throttle angle, the pressure of the steering pump and the speed of the vehicle as controlling parameters. 3 In MATLAB/SIMULINK environment, the simulation system of automatic shift for the Scraper was established and the simulation was carried out, which used the improved back propagation neural network algorithm of intelligent shift control strategy based on the analysis of different intelligent shift control strategy. The simulation results showed that the Scraper intelligent shift control system based on improved back propagation neural network algorithm is feasible and the intelligent shift control system of the Scraper can ensure the transmission system of the Scraper often work in highly efficient area of the converter in order to achieve the purpose of saving energy.4 By taking 2 cubic Scraper for experimental object, the experiment of traction force and speed was carried on, and the matching calculations of the transmission system were verified.