城市地面轨道交通的运营线路通常采用共享路权的模式，这种模式下会出现行人不遵守交通规则、社会车辆占用有轨列车车道等一系列路面突发状况，单纯依靠驾驶员人工瞭望无法保障运行安全，地面轨道交通事故时有发生。

        非接触式障碍物检测系统（毫米波雷达）是一种探测地面轨道列车前方100米范围内运动目标的障碍物检测系统。系统由车载检测装置和车载控制主机两部分组成。车载检测装置采用远、近距离双毫米波雷达传感器进行检测，远距离毫米波雷达主要针对列车前方100米范围内障碍物进行探测，近距离毫米波雷达则针对50米范围内列车周边更广区域进行二次探测，检测数据通过线缆传输给车载主机。当检测到的障碍物尺寸超过设定阈值，车载控制主机输出声光报警信号，给予驾驶员示警。

       毫米波雷达具有全天候工作的特点，能够探测目标的距离、速度、角度等多维参数信息。双毫米波雷达则保证了障碍物探测信息的准确性，从而大大提高了系统的可靠性。

    The operation line of urban ground rail transit usually adopts the mode of sharing road rights. In this mode, there will be a series of road accidents, such as pedestrian disobeying traffic rules, social vehicles occupying rail train lanes and so on. Simply relying on the manual observation of the driver can not guarantee the safety of operation, ground rail traffic accidents occur from time to time.

        Non-contact obstacle detection system (millimeter-wave radar) is a kind of obstacle detection system which detects the moving target within 100 meters ahead of the ground track train. The system consists of two parts: the on-board detection device and the on-board control main engine. The on-board detection device using remote and close range dual millimeter wave radar sensor for detection, and the long-range millimeter-wave radar is mainly used to detect obstacles within 100 meters in front of the train. The millimeter-wave radar at close range carries on the second detection to the wider area around the train in the range of 50 meters, and the detection data is transmitted to the main engine of the vehicle through the cable. When the size of the detected obstacle exceeds the set threshold. Vehicle control host output acousto-optic alarm signal to the driver warning.

        Millimeter-wave radar has the characteristics of all-weather operation, it can detect multi-dimensional parameter information such as distance, velocity and angle of target, while dual-millimeter-wave radar ensures the accuracy of obstacle detection information. Thus, the reliability of the system is greatly improved.