農用搬運車懸吊系統之設計與模擬分析

Abstract

農用搬運車為一款本土產業自主研發與成功製造的農機，主要做為運輸農用物品及收成後之農穫物，因其良好的地形適應能力，廣受農民之喜愛，也著實減輕了農民的農務辛勞。 近年來臺灣的農業工作環境已有很大的改變，國內業者的製造技術也相對成熟，已經能製造出各式各樣不同種類之農用搬運車，若能再將一般車輛上已經成熟之許多技術帶入農用搬運車，相信一定能讓搬運車更為成熟。而本研究目的在改善農運搬運車之懸吊系統進而提升搬運車之舒適性。 本研究先使用電腦輔助軟體ADAMS/Car建立懸吊系統模型與農用搬運車全車模型並進行模擬分析，再利用車輛之1/4模型搭配MATLAB進行控制器設計。本研究搬運車之時速為20、30及40公里，路面為自行建構之sin波路面，搬運車重量視為一不確定性，考慮200~1800 kg之搬運車重量，利用強韌控制之理論進行控制器設計。 模擬結果顯示垂直方向加速度會隨搬運車之時速增加，此控制器能將搬運車在時速20~40公里間時域之垂直方向加速度大小降下來。再將此結果經快速傅立葉轉換後觀察發現，其在搬運車行經不平路面段時之頻率，也就是約為1.1 Hz時之大小有明顯之降低。而在4~10 Hz間之大小皆會略為增加一點，但根據ISO 2631-1 舒適性評估指標，其皆在人體可接受範圍內。

Agricultural transporters are one type of agricultural machinery which are developed and made successfully by local companies. The major function of an agricultural transporter is to transport farm crops and products. Moreover, because of their great adaptability to landform, these machines are applied extensively to reduce human labor. In recent years, the agricultural environment has changed dramatically. Domestic manufacturers have a great deal of experience with fabricating technology, so they already have the ability to make a variety of agricultural transporters. If we can further introduce this technology to other vehicles, more progress can be made in the field of agricultural transporters. This research focuses on the suspension system in order to further improve the ride comfort of agricultural transporters. In this paper, a computer aided engineering software called ADAM/Car was used to build the suspension system and transporter model. Then a quarter car model and MATALB software were also used to design the controller. The result of this simulation shows that the vertical acceleration increases with speed. This controller can reduce vertical acceleration value from 20 to 40 km/h in the time domain. The Fast Fourier Transform was also used to transform the result to the frequency domain. When the transporter travels on an uneven road, the result shows that the gain in 1.1 Hz was apparently reduced in the frequency domain. Although the gain in 4 to 10 Hz only increased slightly, according to the ISO 2631-1 comfort index, the results still fall within an acceptable range for humans.