Theoretical Methods for Precision Increment of Earthwork Made by Power Shovel Actuator

Abstract

Single-bucket shovels take their place in earth working due to their flexibility, universality, and possibility of their usage in the solution of various building problems. Strict demands for earth-working accuracy are stated in different standards and laws, such as Russia's SNiP (Stroitel'nye normy i pravila-building norms and rules). Such rules allow soil shortage of not more than 0.05 m while making earthworks. Possible biases of the shovel's cutting-edge trajectory may be caused by kinematical and dynamical factors. By means of mathematical modeling, possible biases is obtained. It is caused by technological errors of the links of kinematical chain, movement biases of hydraulic cylinders rods, and temperature expansion of machine parts. The sum of such biases exceeds the amount of 0.05 m stated by SNiP. When a mathematical model of the ear working process is developed with dynamical characteristics, it shows additional biases of the shovel's cutting-edge trajectory. Based on the foregoing, it seems difficult to make earth working of appropriate accuracy. The solution of this problem is developed. It is offered to use a new method to introduce adjustments to control system of power shovel, which is based on moving average. The research held shows the efficiency of this method in a wide range of cases: with different distributions laws, with systematical biases, and with different amount of measurements. The offered method allows obtaining positive results of the regulation for any earth-working process.