本論文使用雙頻式超音波測距法，來改良傳統超音波測距法的準確性。我們透過系統模擬實驗，驗證方法的可行性及其特性探討。經由模擬實驗之結果，若使用最佳化參數進行模擬，在最大3000mm之量測範圍內，最大之量測誤差在0.03mm以下。而使用改良後的超音波測距平台所實測的結果發現，設定發送頻率為39007Hz和39192Hz，兩頻率發送間隔0.7ms，激發150個波，取用波峰波谷到達時間數據130到210區段在使用10次同條件不同實驗數據加以平均的情形下，可達到小於0.1mm的重複精度。 This paper use dual frequency method to improve the accuracy for traditional ultrasonic measurement. We simulate the system to confirm the dual frequency method feasibility and the characteristic. If use optimization parameter to simulate, you can get the maximum measurement error below 0.03mm in the maximum measurement distance of 3000mm. Using the improved platform and exciting frequency of the 39007Hz and 39192Hz, two frequency transmissions are separated by 0.7ms, the arrival time range is 130 to 210 data and average of 10 samples, the STD of 0.1mm can be achieved.
