人的木薯块根拔起过程自适应调节机理的试验研究

为了探明经验丰富薯农块根拔起过程的自适应调节机理,采用田间物理试验(高速摄像、块根拔起过程测定)和问询调查相结合的方法,对有经验薯农的木薯块根拔起过程进行了试验研究,从而为木薯收获机械拔起控制系统设计提供依据。结果表明:对于不同土质和块根生长的情况,薯农木薯块根拔起自适应调节过程不同。薯农依据自身经验,先通过试探感知拔起难度,后确定和修正块根拔起方式,进行块根拔起过程控制。对于土质硬度小和块根长度短、生长深度浅的情况,试探阶段结束后,将块根拔起速度控制在一个适当的水平,把块根直接拔出。对于土质硬度较大或块根长度较长、生长较深的情况,试探阶段结束后,先进行抖动拔起,后对拔起速度进行修正,停止抖动操作,把拔起速度维持在一个适当水平拔出块根。对于土质硬度大或块根长度长、生长深的情况,试探阶段结束后,先进行抖动松土,使土壤破裂和破坏土壤与块根的粘附力,以减小土壤阻力和拔起难度,后修正拔起方式,加大抖动速度,把块根拔出。本文为木薯收获机械拔起速度控制系统设计提供了依据。

Experimental Study of Adaptive Regulation Mechanism of People Uprooting Cassava

As to investigate adaptive regulation mechanism during the process when experienced farmers uprooting cassa-va, this paper, making use of high speed camera in field physical experiment, measurement of uprooting process and oral questions, conducts an exploratory study of cassava tuber pulling process by experienced farmers. The results show that for different soil and cassava tubers, adaptive adjusting process varies when farmers pull cassava tuber. Based on their own experience, farmers first probe the difficulty of pulling up, then determine and adjust the root pulling methods, and finally make control of root pulling process. For low soil hardness, short root length and shallow depth of the growth, farmers make uprooting speed in a appropriate level after the trial stage and then pull the root directly. For greater soil hardness or longer root length and shallow depth of the growth, farmers first pull up the root jitterly manually after the tri-al stage, make correction of pulling velocity and stop dithering. Finally farmers pull out cassava tubers by maintaining the pulling speed at an appropriate level. For greater soil hardness or longer root length and deep growth, after the trial stage, farmers first jitter to loosen the soil which leads to the soil rupture and destruction of adhesion force between soil and cassava tubers. As a consequence, soil resistance and difficulty of pulling up are reduced. And then uprooting way is adjusted, the jitter rate is increased while the jittering frequency is decreased. Finally, cassava tubers is pulled out by farmers.