Abstract

The automation of the land excavation machines can find applications in the excavation of soil in both terrestrial and planetary mining and construction. In the process of automating an earthmoving machine, we have utilized a model of soil-tool interaction that predicts resistive forces experienced at the tool during digging. The predicted forces can be used to model the closed loop behavior of a controller that serves the joints of the excavator so as to fill the bucket. Accurately predicting the excavation force that will be encountered by digging tools on the soil surface is a crucial part of designing of mini hydraulic excavator. Based on principles of soil mechanics, this paper focuses on application of an analytical model that is relatively simple and easy to determine required resistive force. Here, soil parameters like soil cohesions, soil density and soil surcharge etc. that can be determined by traditional soil strength tests and taken as reference. The excavation force is investigated and it is helpful in designing of the components of kinematic linkages. This paper emphasize on graphical representation of the relations between excavation force and different parameters like soil density, soil blade friction angle, soil cohesion, internal friction angle and depth of tool. This paper evaluates the digging force based on fixed bucket size of 300 mm length × 300 mm width × 300 mm depth and the minimum digging depth up to 1.5 m especially designed for construction applications.