沈阳农业大学学报2026，Vol.57Issue(4)：97-111,15.DOI:10.3969/j.issn.1000-1700.2026.04.010
丘陵小型农机三点悬挂倾角前馈控制系统研究
Feedforward Control System for Inclination Angle of Three-Point Hitch Mechanism of Small Agricultural Machines in Hilly Areas
摘要
Abstract
[Objective]To address the problems of large hydraulic delay,low control accuracy,and severe inertial overshoot in the three-point hitch system of small unmanned tractors equipped with light implements when operating on hard terrain,due to the use of hydraulic on-off valves and strong pressure operation mode,this paper studies and designs a feedforward CP-bang-bang lift control system based on a piecewise compensation pre-model.[Methods]This system uses inclination sensors installed on the vehicle body and the lower pull rod to obtain the real time lift angle through the vehicle body attitude feedback compensation method,and automatically offsets the body pitch disturbance caused by terrain undulations,and establishes a one-dimensional geometric control model of the three-point hitch.Considering the dynamic asymmetry of the hydraulic system in the lifting and lowering conditions,the area identification method is used to establish the open-loop transfer functions of the system respectively,and a CP compensation pre-model is constructed based on this.This model predicts the sliding amount caused by the system's motion inertia and performs feedforward compensation on the timing of the on-off valve's closure,and combines the bang-bang control strategy to construct a CP-bang-bang controller.[Results]Simulation and field comparison test results show that under the same conditions,the perfor-mance of the improved CP-bang-bang controller is significantly better than that of the traditional bang-bang controller.Test data show that compared with bang-bang control,the average absolute positioning error of the CP-bang-bang controller is reduced from 2.00° to 0.87°,and the stop bar accuracy is improved by 56.5%;the average adjustment time is shortened from 2.84s to 2.62s.[Conclusion]This study proves that under the premise of using conventional hydraulic on-off valves,the piecewise compensation feedforward method can effectively overcome hydraulic delay and system asymmetry,achieving rapid and precise control of the hitch height,which is of great significance for the performance optimization of intelligent agricultural machinery equipment in hilly areas.关键词
三点悬挂/CP-bang-bang控制/液压延时/动力学非对称性/前馈控制Key words
three-point hitch/CP-bang-bang control/hydraulic delay/dynamic asymmetry/feedforward control分类
农业科技引用本文复制引用
张闻宇,蔡希扬,曾山,孙杨,卢一鸣,郑乐,高巧明..丘陵小型农机三点悬挂倾角前馈控制系统研究[J].沈阳农业大学学报,2026,57(4):97-111,15.基金项目
贵州科技计划项目(黔科合支撑[2024]100) （黔科合支撑[2024]100）
广东省基础与应用基础研究基金项目(2025A1515012286) （2025A1515012286）
山东省重点研发计划项目(2022SFGC0202) （2022SFGC0202）
华南农业大学创新训练项目(X202510564128) （X202510564128）
华南农业大学工程学院创新创业项目(2024105641198) （2024105641198）
