一種用于壓力傳感器的溫度控制系統(tǒng)設計

摘 要:針對SiC高溫MEMS壓力傳感器易受溫度影響，產生零點漂移、測量誤差增大等問題，設計了一種溫度控制系統(tǒng)，根據科恩-庫恩公式建立了系統(tǒng)的數學模型，采用參數自整定PID控制算法，克服了純 PID 控制有較大超調量的缺點，實現了一個溫度控制系統(tǒng)。利用Matlab仿真軟件的Similink模塊建立系統(tǒng)的仿真模型，通過仿真和測試驗證系統(tǒng)滿足設計要求。解決了大溫度范圍下壓力傳感器難以補償的問題，使得壓力傳感器在高溫環(huán)境下的應用得以實現，提高了壓力傳感器的穩(wěn)定性。

關鍵詞:MEMS; 壓力傳感器; 溫度控制; 零點漂移

中圖分類號:TN911.7; TN86 文獻標識碼:A

文章編號:1004-373X(2010)14-0157-02

Design of Temperature Control System for Pressure Sensors

GUO Jiang

(College of Information Engineering， Southwest University of Science and Technology， Mianyang 621010， China)

Abstract: A temperature control system for the SiC MEMS pressure sensor is designed as the pressure sensor is susceptible to high temperature， and easy to result in zero drift， and measurement error increase. A mathematical model for the system is established according to Cohen-Coon formula. And finally a temperature control system is achieved with the parameter self-tuning PID control algorithm to overcome the shortcoming of a large overshoot adjustment of pure PID control. The Similink module simulation model was set up by the Matlab Simulation software system. The simulation and testing verifies that the system can meet the design demands. The pressure sensor is hard to be compensated within a large temperature range is solved， with which the application of the pressure sensor in high temperature environments is achieved and the stability of the pressure sensor is improved.

Keywords: MEMS; pressure sensor; temperature control; zero drift

0 引 言

在微電子器件領域，針對SiC器件的研究較多，已經取得了較大進展，而在MEMS領域針對SiC器件的研究仍有許多問題亟待解決。在國內，SiC MEMS的研究非常少，因而進行SiC高溫MEMS壓力傳感器的研究具有開創(chuàng)意義。碳化硅(SiC)具有優(yōu)良的耐高溫，抗腐蝕，抗輻射性能，因而使用SiC來制作壓力傳感器，能夠克服Si器件高溫下電學、機械、化學性能下降的缺陷，穩(wěn)定工作于高溫環(huán)境，具有光明的應用前景。

然而當外界溫度較大時，壓力傳感器受溫度影響精度不高，會產生零點漂移等問題，從而增大測量誤差。于是嘗試加工一個腔體，把壓力傳感器和溫度傳感器放置在里面形成一個小的封閉腔體，在外界溫度較高或較低的情況下，用加熱裝置先升溫到幾十度并維持這一溫度，給壓力傳感器做零點補償，提高壓力傳感器的測量精度。……