基于扰动观测的玉米摘穗收获自适应控制系统研究

Adaptive Control System for Corn Ear-picking Harvesting Based on Disturbance Observation

摘要:

为减少玉米收获机在复杂时变作业环境下的不确定性扰动及时滞问题，提高收获机控制系统抗扰性及玉米收获质量，以摘穗损失率为控制目标，以拉茎辊转速、作业速度和割台高度为主要控制子系统，提出一种基于扰动观测的玉米摘穗收获自适应调控方法。首先，针对收获机作业环境和系统特性，构建了玉米收获机摘穗系统模型;其次，采用并联型的加权PI控制器对各子系统预期目标值进行优化;然后，以自抗扰控制（Active disturbance rejection control，ADRC）作为反馈环节，采用扩张状态观测器在线估计系统内外部扰动，并进行补偿;最后，搭建了收获机自适应控制系统模型，对系统控制策略及各子系统控制性能进行仿真试验和田间试验验证。试验结果表明，各子系统均可以按照既定的控制规则协调工作，并能够快速稳定地实现控制目标，稳态误差最终收敛为0，具有较强的抗干扰性能力，控制效果良好。

Abstract:

To mitigate the issues of uncertainty disturbances and time delays faced by corn harvesting machines in complex and time-varying operational environments, and improve the disturbance rejection capability of the control system as well as the quality of corn harvesting, an adaptive control method based on disturbance observation was proposed for corn ear-picking harvesting. This method targeted to minimize the ear loss rate and utilized the rotational speed of the pulling rollers, operating speed, and header height as the primary control subsystems. Firstly，tailored to the operational environment and system characteristics of the harvester, models of the corn ear-picking system were constructed. Secondly, a parallel weighted PI controller was employed to optimize the desired target values for each subsystem. Thirdly, utilizing active disturbance rejection control （ADRC） as the feedback mechanism, an extended state observer was implemented to estimate and compensate for both internal and external disturbances in the system online;Finally, an adaptive control system model for the harvester was established, and simulation experiments were conducted to evaluate the effectiveness of the harvester system control strategy and the control performance of each subsystem. Field experiments were also conducted to verify the effectiveness of the control strategy. Experimental results demonstrated that all subsystems collaborated seamlessly according to predefined control rules, achieving control objectives quickly and stably with steady-state errors eventually converging to zero. The system exhibited strong anti-disturbance capabilities and achieved satisfactory control effects.