GPS自動噴藥機之開發一變率施噴系統基礎研究

Abstract

本研究以一農用桿式噴藥車為研究對象，於該噴藥車上架設全球定位系統接收儀，以便即時獲取噴藥車在田區的空間座標，並於噴藥車的施噴系統加入比例式流量控制閥。比例閥閥口開度所對應的相對流量與接收儀即時定位精度則由實驗結果獲得，從而找出系統施噴工作曲線與接收儀即時定位誤差。首先個別設計變率施噴系統，然後再對系統進行實驗模擬與分析。在施噴系統方面，利用控制系統的回流量來改變施噴量，以動態方式測試此系統，在不同幫浦設定壓力下比例閥閥口開度與回流量關係，最後將實驗數據進行迴歸分析，以了解比例閥開度特性，並找出其工作曲線。實驗結果分析顯示：比例閥閥口對流量可控制開度在11％~64％間，若將開度以三段20％、40％、60％設定再配合五種設定壓力，則能產生施噴量從7LPM~34LPM 的15 段變率施噴效果，可以運用在多變的作業環境上。 In the field, the real time position of the boom sprayer is obtained from a GPS receiver according to its space coordinate data. For the spraying system in the boom sprayer the feasibility is investigated by adding a proportional flow control valve. The opening of this control valve corresponding to the flow rate and real time error of the GPS receiver are obtained by experiment. First, a variable-rate spraying system and a positioning system was designed and tested separately. In the spraying system, system backflow rate is used to control the spraying rate. Then this system was tested dynamically in order to understand the influence of various setting values of the proportional control valve vs. backflow rate under the different pressure setting values of the pump. Finally, the data was analyzed by means of the regression method to predict the characteristics of the system performance. The experimental results show that for the backflow rate the controllable range of a proportional valve is within ll%¡X64%. The range is then divided into 3 stages : 20% 40%and 60%, with 5 various pump spraying pressures. There were 15 different variable-rate spraying outputs. For the purpose of variable environment, the spraying capacity is from 7 LPM to 34 LPM.