小型割前脱粒收获机双滚筒恒速控制研究

对一种小型割前脱粒收获机双滚筒恒速控制问题进行了研究。建立了行走速度与滚筒角速度的数学模型,确定了在作物密度不可控的情况下,可以通过控制行走速度来稳定滚筒角速度。进行基本试验得到了收获机在额定工作时的喂入量和滚筒转速范围,以此作为恒速控制的基准值。在实际工作过程中,滚筒转速传感器实时检测滚筒转速反馈给控制器,控制器通过控制步进电机调节变量泵排量来控制收获机减速或加速,从而稳定滚筒转速。试验结果表明:该控制系统提高了割前脱粒收割机双滚筒工作转速的稳定性,减轻了操作者的劳动强度。

Seeding Depth Real-time Monitoring System for a No-till Planter

In order to improve the consistency of seedling on the straw mulching farmland, a deformation sensor made of polyvinylidene fluoride, or PVDF, film is fixed on the inner surface of depth wheel with two different types to monitor the deformation of the wheel in real-time.According to the deformation, the seeding depth can be measured indirectly, and the two different types of sensor are compared.The system hardware circuit can amplify and filter the signal generated by the sensor, and can extract the signal peak.The system is able to monitor the seeding depth in real-time based on the peak signal.The result shows that the output peak voltage of the two types of sensor is linearly proportional to the load of the depth wheel.And the sensitivity of the arched sensor is significantly higher than that of the tiled sensor.When the speed of the planter is between 5Km/h to 8Km/h, the accuracy of the system is more than 85%.