Optimization of Turning Maneuvers in Reversible Motion of an Automated Agricultural Machine-Tractor Unit

Path planning is a crucial component in the application of unmanned agricultural technologies. Machine-tractor units (MTAs) equipped with automated control systems and mounted agricultural implements are capable of executing non-standard motion trajectories and turning maneuvers under fi eld conditions, including reversible motion on sloped terrain. On small- contour plots, the proportion of idle travel is relatively high; therefore, reducing travel distance or turning time can increase the productivity of agrotechnical operations. ( Research purpose ) To calculate the optimal turning maneuver during reversible motion of an automated machine-tractor unit. ( Materials and methods ) The calculation of optimal motion within the turning zone is a key element of route planning aimed at improving the operational efficiency of a machine–tractor unit (MTA). Under constrained headland conditions, optimization of the turning trajectory becomes a complex dynamic nonlinear problem that is difficult to solve using traditional numerical methods. The study considered Lagrange’s second-order differential equations describing the curvilinear motion of a machine-tractor unit (MTA) in Cartesian coordinates. However, the solutions of this system of equations, which defi ne a family of “needle turns” for reversible motion, are inherently constrained. Therefore, to compute a short turn under constrained conditions, a turning zone optimization method was used. ( Results and discussion ) The study led to the development of kinematic models of a machine-tractor unit (MTA) equipped with a rotary mower and to the formulation of motion optimization problems within the turning zone under operational constraints. Turning scenarios ranging from symmetric to asymmetric needle turns were evaluated, and the optimal configuration was identified. Integration of the machine-tractor unit (MTA) model into the technological workflow enabled the calculation of an alternative turning option, a shaped turn with specific parameters for the given operating conditions. ( Conclusions ) Analytical studies of the automated agricultural machine–tractor unit (MTA) with a rotary mower demonstrated that the geometric and performance parameters of the shaped turn fall within a minimum turning width of 3.65 meters and a path length of 7.74 meters, corresponding to the technical characteristics of the Uralets 22 mini-tractor and the N-17 rotary mower.