电阻式触摸屏多点校准及触摸压力研究

Research on Multiple-point Calibration and Touch Pressure of Resistance Touch-screen

针对电阻式触摸屏在小点状目标应用环境中存在触点判断不准确、灵敏度不高的问题,提出两种改进措施;其一在现有三点校准算法基础之上,增加校准点数提高转换精度;通过贪心算法对随机校准点集进行优化约简,并利用最小二乘法求得校准系数;其二为提高触摸坐标的准确性和触摸方式的鲁棒性,加入触摸压力检测和阈值判定来去除无效点击;测试结果表明,基于贪心算法的多点校准可提高坐标校准系数的精度,而触摸压力判定的加入则有效提高了轻触时的坐标精度。

For the inaccuracy and low sensitivity of the resistive touch--screen to fix position in small point target application, more points were collected to increase conversion accuracy based on existing three-- point calibration. Greedy algorithm optimized and simplified the random calibrating spots, then least squares fitting algorithm calculated optimal calibration parameters with siruplified spots assemble. In or der to improve the accuracy of contact coordinate and adaptability of touch mode, the system adopted touch pressure measurement and thresh- old decision procedure to remove invalid click. Finally, test results show that multi--point calibration using greedy algorithm can improve the precision of coordinate calibration coefficients, and the adoption of Pressure Judgment increases the accuracy of gently touching coordinates effectively.