针对传统的电阻分压法获取阻值范围小、精度低等问题,文章提出了一种基于电流转换获取阻值的高精度检测法。首先,通过采用ARM处理器同时控制扫描电压动态变化和调整I/V转换电路中的反馈电阻阻值,借助2个方面的配合实现检测量程依据施加压力的大小进行自适应最优选择;在此基础上,通过控制多路复用模拟开关进行多通道信号采集;最终设计了一种用于手掌压力分布的实时检测系统。实验结果表明,采用该设计方案取得了较精确的测量效果,有效克服了传统方法的缺点。
Aiming at the small sampling range and low measurement accuracy of traditional resistor divider method, a high-precision pressure detection method is put forward based on current conversion to obtain re- sistance value. Firstly, it controls the scanning voltage dynamic change and adjusts the feedback resistor on I~ V conversion circuit by ARM processor. For they are coordinated, the optimal range can be detected adaptive- ly according to the size of pressure. On this basis, it achieves the multi-channel signal acquisition by control- ling multiplexing analog switches. Finally, a real-time detection system for palm pressure distribution is de- signed. The experimental results show that the design makes more accurate measurement results and effec-tively overcomes the shortcomings of the traditional methods.