Simulation model of the manipulator workflow when removing uncontrolled vegetation along with the root system in forest plantations

One of the urgent problems that arises when growing long-term forest stands is the problem of timely and high-quality sapling thinning. Manual or mechanized cutting or clearing of uncontrolled trees and shrubs often results in their survival. One of the methods for destruction of such vegetation that protects the cleared areas from its regeneration is a method for removing uncontrolled underwood including the root system that is performed by using a working body attached to the end of the manipulator arm of a multifunctional machine. The authors take into account the results previously obtained when modeling the spherical working space of machines with manipulator installations. To determine the optimal values of the design and technological parameters of the manipulator with a working body located at its end the authors have developed a mathematical model describing the process of these technical means influence on the uncontrolled underwood, providing high performance and quality characteristics of both the manipulator itself and the working body. This modeling was based in general on the methods of classical mechanics. To substantiate the kinematic parameters of the manipulator and the working body the authors have developed a number of design schemes indicating the positions of the pulled out underwood in several coordinate systems. These coordinates included the characteristic points of the uncontrolled underwood with substantiation of the features of their adoption, points of application of external forces (driving moments and moments of resistance movement, gravity of the manipulator elements) acting on the manipulator and the working body. The authors have compiled a number of time-dependent differential equations of the movement of the manipulator elements (platform, rotary rack, body and rod); the graph of the manipulator workflow indicates the initial parameters and nominal displacement values. Based on the developed mathematical model for a number of initial conditions, the authors have calculated the trajectories, constructed the graphs of the movement of the characteristic points of the manipulator and the underwood, and proposed the directions of further application of the obtained control actions.