履带式联合收获机全向调平底盘设计与试验

针对履带式联合收获机在不平坦地表作业时，车体随地形起伏而倾斜，造成作业效率降低、驾驶员舒适性变差、安全性降低的问题，设计了一种履带式联合收获机全向调平底盘。该底盘由上架、下架、升降机构和电液控制系统组成，可实现联合收获机底盘倾斜时的自动与手动调节，纵向调节范围为-5°~7°，横向调节范围为-6.5°~6.5°，底盘最大提升高度为130mm。阐述了全向调平底盘的工作原理、电液控制系统结构与调平控制策略，进行了针对底盘性能的静态与动态调平的验证试验。静态调平试验对底盘前最低、后最低、左最低、右最低、左前最低、右前最低、左后最低、右后最低8种倾斜状态进行调平，结果表明，自动调平系统最长调节时间为8.2s,平均调节时间4.2s，倾斜度调节误差最大值为0.67°。动态调平试验针对自动调平控制、手动调平控制和固定地隙调平控制3种调平控制模式，进行了坡地、畦沟田块、水田等地形下的调平对比试验。在坡地与畦沟田块试验中，自动调平控制模式可以改善底盘的倾斜状态，提高底盘的稳定性；手动调平控制模式有一定的调节作用，但调节稳定性较差。在水田试验中，自动调平控制模式调平效果优于坡地与畦沟田块，说明在地形起伏较小的条件下，自动调平控制系统调平效果更好。动态调平试验表明，自动调平系统可以减小底盘倾斜度，提高底盘稳定性，增强联合收获机对不平坦地表的适应性。

Design and Test of Posture Controlled Chassis for Caterpillar Combine

Considering the fact that the tracked combine inclined with the undulation of the terrain when it worked on the uneven ground, which resulted in the reduction of the working efficiency, the poor driving comfort and the low safety of the manipulator, a kind of posture controlled chassis of the tracked combine was designed. The chassis was composed of upper frame, lower frame, lifting mechanism and electrohydraulic control system, which can realize automatic and manual adjustment when the combine chassis tilted. The longitudinal adjustment range was -5°~ 7°, the transverse adjustment range was -6.5°~ 6.5°, the maximum lifting height of the chassis was 130mm. The working principle of posture controlled chassis, the structure of electrohydraulic control system and leveling control strategy were described, and then static and dynamic leveling verification tests for chassis performance were carried out. The static leveling test was carried out on the eight tilting states of the chassis: the lowest in front, the lowest in rear, the lowest in left, the lowest in right, the lowest in front, the lowest in right, the lowest in rear and the lowest in right. The test result showed that the maximum adjustment time of the automatic leveling system was 8.2s, the average adjustment time was 4.2s, and the maximum inclination error was 0.67°. The dynamic leveling experiment was carried out for three leveling control modes: automatic leveling control, manual leveling control and fixed gap leveling control. In the experiment of slope and furrow field, the automatic leveling control mode can improve the tilt state of chassis and the stability of chassis. The manual leveling control mode had a certain adjustment effect, but the adjustment stability was poor. In the paddy field experiment, the leveling effect of the automatic leveling control mode was better than that of the slope and furrow fields, which showed that the leveling performance of the automatic leveling control system was better under the condition of small terrain fluctuation. The dynamic leveling test showed that the automatic leveling system can reduce the inclination of the chassis, improve the stability of the chassis and enhance the adaptability of the combine to the uneven ground.