磁阻传感器在强磁场干扰下会导致灵敏度降低,使用环境温度变化会导致零点偏移电压及灵敏度变化,传感器使用的环境磁场也会影响测量结果。为解决上述问题,提高新型车辆检测仪的智能水平,对新型智能车辆检测仪灵敏度的自修复与自校准技术进行了研究,新型智能车辆检测仪采用磁阻传感器作为敏感元件,通过对自修复线圈施加强电流脉冲产生强磁场重新磁化磁阻传感器的方法进行车辆检测仪的灵敏度自修复,通过对自校准线圈多次施加电流产生特定磁场对车辆检测仪的零点偏移电压和灵敏度进行自校准,同时可消除环境磁场对测量结果的影响。针对车辆检测仪强磁干扰后的灵敏度自修复,自校准进行了对比实验。实验结果表明,采用的方法能够对智能车辆检测仪的灵敏度进行自修复和自校准。
Geomagnetic sensors can be affected by large magnetic disturbing fields,which may lead to output signal degradation;and surrounding temperature variation can make zero offset voltage and sensitivity to change;in addition environmental magnetic field also has influence on measuring results.To solve the above problems and enhance the intelligence level of vehicle detector,study on the sensitivity self-healing and self-calibration of new intelligent vehicle detector was carried out.The vehicle detector uses geomagnetic sensor as the sense element.A large pulse current is exerted in the self-healing coil,which generates a large magnetic field to re-magnetize the magnetic sensor,and the self-healing of the detector sensitivity is implemented.A certain current is exerted in the self-calibration coil for several times to generate a specific magnetic field,which carries out the self-calibration of zero offset voltage and sensitivity,at the same time the influence of environmental magnetic field can be removed.Comparison experiments on sensitivity self-healing and self-calibration were carried out;experiment results show that the proposed technique can implement the sensitivity self-healing and self-calibration for intelligent vehicle detector.