Authors

Abstract

In response to the issues faced by conventional combine harvesters' threshing drums, such as the difficulty in maintaining stable speed due to load fluctuations and torque disturbances, as well as the limited speed adjustment range to adapt to changes in crop varieties and properties, this study proposes a novel dual power source threshing drum (DPSTD). By incorporating a power coupling device and a motor into the existing mechanical structure, the DPSTD utilizes the flexible speed and torque output capabilities of the motor to achieve a wide speed adjustment range and enhance its resistance to interference. A robust model predictive control strategy is designed based on finite time disturbance observer (FTDO) to compensate for torque under load fluctuations. Simulation results demonstrate that the DPSTD can achieve rapid and accurate speed regulation. Moreover, under torque disturbances and load mutations, the DPSTD with the torque compensation control strategy, can reduce the speed error by 73.90%. This significantly improves the speed tracking performance of the threshing drum, exhibiting good anti-interference capabilities. Finally, the superiority of the DPSTD is validated through bench tests, confirming its effectiveness and feasibility and providing new insights for control research on threshing drums.

Abstract in Chinese

针对传统联合收获机脱粒滚筒面对负载波动和扭矩干扰时难以稳速影响作业效果，以及调速范围小难以适应作物品种和属性的变化等问题，本文基于并联式混合动力技术提出了一种新型双动力源脱粒滚筒 (DPSTD)，通过在原有的机械驱动结构上加入动力耦合装置和电机，利用电机灵活的转速和转矩输出功能实现脱粒滚筒的大范围调速并提高抗干扰能力。本文对DPSTD各部件进行数学建模，并设计了基于有限时间干扰观测器 (FTDO)的电机鲁棒模型预测控制策略，以实现DPSTD在负载波动和干扰下的扭矩补偿，进一步对DPSTD的调速和稳速性能进行研究，仿真结果表明，DPSTD可以快速精准地进行转速调节，并且在存在扭矩干扰和负载突变的情况下，采用扭矩补偿的控制策略的DPSTD可以将脱粒滚筒的转速误差均方根值降低73.90%，最大转速误差降低76.18%，冲击度均方根值降低33.51%，最大冲击度降低73.18%。可明显改善模式切换平顺性和脱粒滚筒转速跟踪效果，具备较好的抗干扰能力。最后台架试验进一步验证了DPSTD的调速和稳速性能，证明了其有效性和可行性，为联合收获机脱粒滚筒控制研究提供了新思路。