具力量感知能力之藍芽智慧刀桿

Abstract

因應工具機之高速切削技術發展，適當的切削力感測器能夠同步監測部分加工參數進而使加工效率與品質達到最佳化，讓加工邁向高速化、細微化、精密化等目標。本研究旨在研發一個直接量測式無線動態切削力感測器，該動態切削力感測器與刀桿結合為一智慧型刀桿，以材料力學和靜力學原理輔助，建立多軸切削力與感測器結構應變之力學模型，並以應變規作為應變量測元件，結合力學模型及全橋式電路原理以消除力之耦合效應、建立數值模型。其後內嵌自行研發之藍芽切削力感測模組(BCFMM)，掛載切削力量測應用程式，包含校正及歸零等功能，並寫入卡曼濾波器之數學模型，再以靜態力量測試對感測器進行校正，根據實驗結果，求出實驗數值模型之力耦合因子及敏感度，並與理論數值模型相互驗證。續將解耦合矩陣之數值運算重新寫入微處理器，進行三個量測通道的力量解耦合之驗證。硬體方面，感測器性能經測試可達到：精度±1.1 N、±2.6 N、±0.37 Nm；量測範圍±1684.2 N、±6407.7 N，±200.72 Nm；取樣頻率2 kHz；解析度24位元；功耗397 mW；模組尺寸Ø50×10mm3。接著，對智慧型刀桿進行動平衡校正，並利用加速規進行剛性分析，驗證模擬結果及其對應主軸轉速之模態安全範圍，才將刀桿式切削力感測器安裝於CNC工具機。最後，根據切削力學原理，建立一個簡化之切削力預測模型，進行切削實驗並驗證，實現智慧刀桿之概念。

In response to the development of high-speed cutting technology for machine tools, a proper cutting force sensor is necessary to monitor machining status in real-time. The purpose is to make the machining process faster and optimize the machining quality. This thesis presents a method for measuring dynamic cutting force based on direct measurement and an innovative design of tool holder which is combined with wireless force sensor. A mechanics model is established and connected to full bridge circuit composed of strain gauges, which is for forces decouple and eliminating heat effect. A Bluetooth cutting force measurement module with Kalman filter is developed and embedded into tool holder. After static calibration, coupling factors and sensitivities can be obtained and verified to mathematical model, the decouple operation will be written into MCU. The performance of force sensor is following: module size Ø50×10mm3; sample rate 2 kHz; resolution 24 bit; accuracy ±1.1 N, ±2.6 N, ±0.37 Nm; measuring range ±1684.2 N, ±6407.7 N, ±200.72 Nm; power consumption 397 mW. Next, the safety of new tool holder is ensured by dynamic balance and modal test. Finally, the force sensing tool holder can be installed to CNC machine tool and conducted functional validation. A simplified cutting force prediction model is established to compare to cutting force signals. After validation, the concept of smart tool holder is achieved.