基于车速传感器的雷达测速仪检定装置

发布时间：2019-03-16 12:34

【摘要】：近年来，我国公路运输发展势头十分迅猛，成为我国经济崛起一大助力。与此同时，道路交通管理问题日益复杂也成为有关部门不得不面临的一大挑战。各种违章、违法现象屡见不鲜，尤以超速行驶危害最大。目前，我国各地有关部门对道路车辆行驶速度的监控主要依赖雷达测速仪。然而，雷达测速仪测速不准的现象时有发生，极大的降低了有关部门执法的公正性和权威性。质疑雷达测速仪准确性和合法性的声音此起彼伏，使其陷入了“测人”需先“测己”的尴尬境地。解决问题的唯一办法就是有关部门运用雷达测速仪检定装置，对雷达测速仪在投入使用前和到计量周期后进行可靠性检定。目前国内市场上雷达测速仪检定装置种类繁多，然而检定条件均比较苛刻，需要在实验室条件下完成，这对于大量固定安装在道路上的测速系统来说，操作起来十分困难，而且检定的环境过于理想化，忽视了道路环境、气候、安装角度、电磁干扰等对雷达测速仪造成的干扰。本文在大量分析和论证的基础之上，开发了一种新的雷达测速仪检定装置。该装置可在雷达测速仪安装位置就地开展检定工作，省去了送检的麻烦，并最大程度的还原了被测系统的使用环境，提高了检定结果的有效性。本文的设计思路是使用该装置与被测雷达系统对同一辆测试用车进行速度采集，并将二者获取的车速数据进行实时对比，以此达到检定雷达测速仪的目的。本装置由车速采集设备和上位机（PC）数据分析软件构成。所需车速信号由车速传感器提供，因其直接来源于车轮转动，，保证了数据的“原生态”，可靠性高。针对磁电式轮速传感器和霍尔式车速传感器分别设计了两种不同的接口，保证设备能够满足大部分测试用车使用。车速采集设备由信号预调理电路、单片机、显示部分和无线收发模块构成。磁电式轮速传感器抗干扰能力差，产生的正弦波信号有大量干扰，且电压幅值受车速影响明显，因此需要对其进行预调理。通过二极管双向限幅电路、二阶有源低通滤波电路和施密特触发器组成的预调理电路，将其转换为频率不变，占空比适中的方波，供单片机计算车速使用；霍尔式车速传感器因其自身优势而不需要经过预调理电路即可用于计算。显示部分为LED数码管，显示车速精确到小数点后一位，便于驾驶人员对速度的掌控。无线收发模块用于单片机与上位机之间的数据传输。为保证数据传递的同步性，我们选取上位机软件为主节点，雷达测速仪与车速采集设备为从节点。主节点在测试过程中，每1ms向两个从节点同时发出数据请求，从节点接收到数据请求命令后，同时向主节点发送车速数据，主节点在接收到二者的车速数据后，进行数据分析、存档并给出检定报告。
[Abstract]:In recent years, our country highway transportation development momentum is very rapid, become our country economic rise a great help. At the same time, the increasing complexity of road traffic management has become a major challenge for the relevant departments. All kinds of violations, illegal phenomena are common, especially speeding the greatest harm. At present, the relative departments of our country mainly rely on radar velocimeter to monitor the speed of road vehicles. However, the phenomenon that the radar velocimeter is not allowed to measure the velocity often occurs, which greatly reduces the fairness and authority of the law enforcement of the relevant departments. The sound of questioning the accuracy and legality of radar velocimeter has caused it to fall into the awkward position of "measuring oneself" first. The only way to solve the problem is to use the calibration device of radar velocimeter to verify the reliability of radar velocimeter before it is put into use and after the period of measurement. At present, there are many kinds of calibration devices for radar velocimeter in the domestic market, however, the verification conditions are relatively harsh and need to be completed in laboratory conditions, which is very difficult to operate for a large number of fixed speed measuring systems installed on roads. Moreover, the verification environment is too idealized, neglecting the interference caused by road environment, climate, installation angle, electromagnetic interference and so on to radar velocimeter. On the basis of a great deal of analysis and demonstration, a new calibration device of radar velocimeter is developed in this paper. This device can carry out on-the-spot verification work in the installation position of radar velocimeter, save the trouble of sending to check, restore the operating environment of the tested system to the maximum extent, and improve the validity of the verification results. The design idea of this paper is to use the device and the measured radar system to collect the speed of the same test vehicle and compare the speed data obtained by the two in real-time so as to achieve the purpose of calibrating the radar velocimeter. The device is composed of speed acquisition equipment and upper computer (PC) data analysis software. The required speed signal is provided by the speed sensor, because it is directly from the wheel rotation, which ensures the "original ecology" of the data and high reliability. Two different interfaces for magneto-electric wheel speed sensor and Hall speed sensor are designed to ensure that the equipment can meet the requirements of most test vehicles. Speed acquisition equipment is composed of signal pre-conditioning circuit, single chip microcomputer, display part and wireless transceiver module. The anti-jamming ability of the magnetoelectric wheel speed sensor is poor, the sine wave signal produced by the sensor has a lot of interference, and the voltage amplitude is obviously affected by the speed, so it is necessary to pre-adjust it. Through diode bi-directional limiting circuit, second-order active low-pass filter circuit and Schmitt flip-flop, the circuit is converted into square wave with constant frequency and moderate duty cycle, which can be used to calculate the speed of single-chip computer. Hall speed sensor can be calculated without pre-conditioning circuit because of its advantages. Display part for LED digital tube, display speed accurate to a decimal point, easy for drivers to control the speed. Wireless transceiver module is used for data transmission between MCU and host computer. In order to ensure the synchronization of data transmission, we select the host computer software as the main node, radar velocimeter and speed acquisition equipment as the slave node. During the testing process, each 1ms sends a data request to two slave nodes at the same time. After receiving the data request command from the slave node, the master node sends the speed data to the master node at the same time. After receiving the speed data of the two slave nodes, the master node carries on the data analysis. File and provide verification report.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U495;TN953.1

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