丘陵山区农用轮式动力底盘仿形行走关键技术研究

With situations that common agricultural machines operate difficultly and agricultural mechanization level is very poor in hill and mountain areas, basing on irregularities in rough terrain, agricultural dynamic chassis with wheeled terrain adaptive locomotion for hill and mountain areas (ADCWTALHMA) is selected as research objective. The theory of multi-wheel driving and terrain adaptive locomotion with multi-degree-of-freedom anywhere and anytime was proposed. The variation of kinematic parameters were researched when the chassis terrain adaptively running in the severe terrains by adjusting the multi-degree-of-freedom passively. Key technologies such as performance parameters including the chassis’ configuration, composition principle, steering, driveline, the passing ability, control measures to keep bodywork horizontal and dynamics characteristic were researched. All the research was also verified by the computer simulations and experiments. ADCWTALHMA can not only have high terrain adaptive locomotion and passing ability but also keep bodywork horizontal by adjustment of the cantilevers’ angles cooperating with rear axle’s transverse terrain adaptive locomotion, which can resolve the two difficult problems of agricultural dynamic chassis’ operating in hill and mountain areas at the same time easily. All the research can impel the procession resolving the bottleneck problem of locomotion about the agricultural dynamic chassis for hill and mountain areas, and can speed ADCWTALHMA’s development.

针对丘陵山区农业机械运行困难、机械化薄弱的问题，根据丘陵山区崎岖不平的地形特点，以适应丘陵山区的农用轮式仿形行走动力底盘为研究对象，提出一种全时多轮驱动、多自由度仿形行走的轮式仿形行走理论，研究底盘通过多自由度调节被动实现丘陵山区崎岖地面仿形行走的运动规律，研究底盘结构、组成原理、转向和动力传递等性能参数以及行走通过性，车体调平控制和动力学特性等关键技术，并进行计算机仿真模拟及试验验证。丘陵山区农用轮式仿形行走动力底盘不仅具有崎岖地面的高适应性和通过性，而且通过悬架悬臂夹角调节与后桥横向仿形协同实现车体调平控制，同时解决丘陵山区农用动力底盘行走、作业的两大难题。本项目的开展可加快丘陵山区农用动力底盘行走技术瓶颈问题的解决及农用轮式仿形行走动力底盘的推广应用。

丘陵山区农业机械行走理论不完善、行走技术短缺及其衍生课题严重制约我国丘陵山区农机化发展，研究特殊形态的行走技术和用行走技术推进的特殊动力底盘极为重要。本项目基于多自由度轮式全地形仿形行走理论，以“通过多自由度被动调节实现丘陵山区崎岖地面行走作业并且通过悬架的悬臂夹角调节与后桥横向仿形协同实现车体调平控制”为初始方案，从“行走机构仿形”及“车体调平”两方面研究。. 针对轮距随农作物行距变化而适应性调整的技术需求，研究轮距调整联动转向原理，提出轮距调整和转向独立或同时进行的轮距可调式转向机构方案，设计系列轮距可调式农用底盘；针对离地间隙随农作物高度变化而大范围无级调整的技术需求，设计升降过程中轮距、轴距不变，具有独立悬架高度调节装置的动力底盘；针对现代化智能机械终端执行件较多的同步液压系统，提出并联转子液压泵流量脉动瞬时同步原理，研制试验样机，完成并联齿轮泵的变量控制试验和并联同步分流器的恒流控制试验。针对车体倾斜等问题，提出“自适应调平”和“动态补偿调平”两种调平机理，分别进行样机试制和试验验证：自适应调平底盘可减小由地形变化引起的侧倾角和俯仰角变化，仿真分析和样车试验都验证底盘侧倾角和俯仰角之和可降低 60%左右；丘陵山区农用仿形行走动态调平底盘4组调平悬架的悬臂夹角可精确调节，不仅能实现全时多轮驱动、多自由度仿形行走，而且通过悬架悬臂夹角调节实现车体调平控制，同时解决行走、作业两大难题，仿真分析和样车试验分别验证底盘可在 0.5°、1°精度范围内实现动态调平；针对“补偿调平”，提出一种预检测主动调平技术原理，提前检测行驶前方地面情况并判断如何实施调平动作，调平动作先于车辆倾斜，可以主动预防、避免或减少车辆在崎岖不平地面上行驶作业时的车体倾斜。. 研究“仿形”和“调平”等关键技术，能提高农用动力底盘在丘陵山区等复杂地面的行走通过性和稳定性，为丘陵山区农用仿形行走动态预调平底盘应用提供参考。