Novel three-degrees-of-freedom hitch mechanism for hillside tractors

Abstract

A hitch mechanism with three rotational degrees of freedom(DOF) is proposed, which can be used on tractor in hill region. The three DOFs hitch mechanism is composed of two telescopic upper links, one lower link and one hanging frame of farm implements. The hitch mechanism can adjust the posture of farm implements and realize the profiling operation on hillside. It can improve the uniformity of the tillage depth during tilling on sloped land. We studied the inverse kinematics solution model of this hitch mechanism, which can be used to control the position and posture of farm implements. Furthermore, we carried out the mechanical analysis of the hitch mechanism and established the mechanical model, which can be used to calculate the lifting force parameters and power parameters of the driving element. The solution method of the important parameters is given in the given workspace of the three DOFs mechanism. Taking a 25kW hillside tractor as an example, under the condition of meeting the ISO tractor's standard, we calculated the length range of the upper link, load of the upper link and the lower link. The calculation results show that this mechanism is feasible for the Hillside tractor.