衛星導航應用在農用車輛轉向系統之初步研究

Abstract

全球衛星定位系統正處於高度利用的熱絡階段，衛星定位不論在汽車、航空、農業、與工業上均有卓越的表現。本文研究的目的是希望開發一套穩定且適合在氣候環境較差之農地當中使用的車輛轉向控制系統。本研究設計改裝一實驗用的無人載具，安裝好當中的硬體設施，之後開始著手進行控制系統的試製。控制器的組成大致上分為: 筆記型電腦、8051單晶片、車身姿態儀、與GPS接收模組等，致動器則是由兩組步進馬達與齒輪組組合而成，為使車速穩定，使用齒輪組作帶動的元件。 實驗方法如下：先建立8051與控制訊號間的傳輸，之後將控制程式寫入晶片中並燒錄完成，第二步做8051與PC之間的溝通，選定與RS232之間的鮑率(1200)，第三步做GPS與PC的溝通、訊號的解析以及定位模式的確立，最後再將軟硬體加以整合後進行實地測試測並設計數組控制參數、藉由不斷的實測與調整來找出最佳的控制參數。由實驗得知當控制參數Kp/Ki/Kd=40/40/40與60/40/40時所得到的結果最佳。

The global positioning system is being at the stage of intensive applications. The satellite positioning, no matter where in the field of automobile, the aviation, the agriculture and the industry excellent performance. The main purpose of this study is to develop a steering control system of agricultural vehicles. At first an unmanned experimental car was designed and the hardware was mounted. The control system was then be done. The control program was written by Visual Basic6.0 as a software environment. The control theory was mainly based on the PID control because the PID system was stable and also if the factors (for example climate、 terrain、and environmental factors) outdoors were unstable for the establishment of control model. By adjusting Kp/Ki/Kd parameters we could try to find an optimal solution for this steering control system. Experiment procedures was starting from translation between 8051 chip and unmanned car 、 tried to burning program into the 8051 chip, then combined all the software and hardware parts, preparing to test on the real road. For conclusion, Kp/Ki/Kd=40/40/40 and 60/40/40 was the optimal solution of our experiment.