EN
The effectiveness of agrocultural processes in wooded areas depends, inter alia, on the kind of machines used. Mobile machines chopping branches with low power engines are characterized by limited adaptation of the drive unit to the operating conditions. This results in increased fuel consumption and increased exhaust emissions. In order to develop innovative control systems that reduce fuel consumption, it is required to determine the conditions of use of such machines. The article characterizes the periodic−variable cycle of chopping wood machines, depending on the frequency of branch delivery. The research was carried out at the following distances of the branch stack from the chipper: 0.5 m; 1.5 m and 2.5 m, indicating the characteristics of changes in the throttle angle (signalling the change in system load). The share of idle and active work time in the process of the waste chopping depending on the distance between the chipper and the pile of branches was determined and described. It was proved that at a distance of about 0.5 m, idle operation accounts for about 22% of the chopping process time, and at a distance of 2.5 m, the share of idle labour increases to ca. 35%. These distances, due to the topography of the terrain in real operating conditions, can be much larger. This suggests that carrying out work on reducing energy consumption and emissions of harmful exhaust compounds, depending on the operating conditions, is justified because the idle operation of the grinding machine can account for even more than 50% of the entire operation of the device. Benefits resulting from the development of innovative control systems for drive units of machines chopping branches are particularly important due to the limitation of the quantitative impact of exhaust emissions on the natural environment and machine operators.