Analysis of Steering Performance of Arch Waist Agricultural Travelling Chassis with Dual Power Flow Differential Steering Mechanism

Abstract

The steering mechanism directly affects the steering performance and operational efficiency of agricultural
machinery. The conventional differential steering mechanism applies to a limited number of turning radii
and often requires components such as brakes. Therefore, a dual power flow differential steering
mechanism has been designed to enable arch waist agricultural travelling chassis to achieve in-situ steering
and any turning radius on any terrain. We established the kinematic model for the differential steering
mechanism's output shaft rotational velocity (input) of the gearbox, shaft rotational velocity of the steering
motor (input), and the rotational velocity of the two semi shafts (output). The kinematic model for the
output shaft rotational velocity (input) of the gearbox, shaft rotational velocity (input) of the steering motor
and turning radius was obtained based on the relationship between the rotational velocities of two semi
shafts and the turning radius of the arch waist agricultural travelling chassis. Additionally, we set up the
dynamics model for the differential steering mechanism's output shaft torque (input) of the gearbox, shaft
torque of the steering motor (input) and the torque of the two semi-shafts (output). Finally, the differential
steering mechanism was installed on the arch waist agricultural travelling chassis to test the steering
performance on the concrete pavement and farmland. The test results revealed that the prototype has good
straight-line stability, with a yaw rate of 0.82%, which is in line with the national standard. The average
minimum radius for in-situ steering on the concrete pavement is 0.033 m. The average minimum radius for
operation on the farmland is 0.040 m, effectively reducing the contact area between the ground and the
prototype. Therefore, it can be widely used in complex terrains such as hills and mountains.