超声波测距系统的研究与实现

发布时间：2018-07-15 09:42

【摘要】：超声波优势在于指向性强、抗干扰能力较强、定向发射能力较强,且在介质中传播的衰减系数较小、反射能力较强等,超声波普遍运用在非接触式检测方式中,主要包括超声波检测距离、超声波检测厚度和超声波定位障碍物等。其中,超声波液位检测在工农业中也有着广泛的应用,因此,精准的液面高度测量成为工农业过程控制的重要组成部分。针对大型蓄水罐的液面高度检测,本文研究并实现一种操作步骤简便、检测精度高、智能化管理控制、制作成本较低的液位检测系统。为了达到提高超声波测距精度的目的,本文研究了利用渡越时间测量方法进行超声波测距的基本方法和理论,分析了影响超声波测距精度的主要因素,并提出了超声波测距系统的总体设计实现方案,对该系统进行硬件电路实现,包含单片机最小系统、超声波发射和接收电路、舵机方向控制电路、无线通信电路、液晶显示电路以及声光报警电路。根据测距系统的逻辑关系编写流程图以及使用C语言完成该系统软件实现。其中,利用卡尔曼滤波算法预估下一次测量液面高度并自动调整量程,以提高超声波传播时间的检测精度;在仅使用一个超声波传感器的情况下,利用标准挡板和舵机相结合的方法,精确测量并计算超声波传播速度,从而计算得到被测液面高度。最后,对超声波测距系统进行实际测量并分析检测结果和误差要素。该系统经过模拟测量,说明各项技术指标全部满足预定要求,且具有硬件电路结构简单、成本低廉、准确度较高等优势,并实现液面高度的实时显示和达到或超过阈值时的双重报警功能。
[Abstract]:The advantage of ultrasonic wave lies in its strong directivity, strong anti-interference ability, strong directional emission ability, small attenuation coefficient and strong reflection ability, etc. Ultrasonic wave is widely used in non-contact detection. Mainly include ultrasonic detection distance, ultrasonic detection thickness and ultrasonic positioning obstacles and so on. Among them, ultrasonic liquid level measurement has been widely used in industry and agriculture. Therefore, accurate liquid level measurement has become an important part of industrial and agricultural process control. In this paper, a kind of liquid level detection system with simple operation steps, high detection precision, intelligent management and control, and low production cost is studied and implemented for the liquid level height detection of large storage tanks. In order to improve the accuracy of ultrasonic ranging, this paper studies the basic method and theory of ultrasonic ranging using transit time measurement method, and analyzes the main factors that affect the accuracy of ultrasonic ranging. The overall design and implementation scheme of ultrasonic ranging system is put forward. The hardware circuit of the system is realized, including the minimum system of single chip microcomputer, the ultrasonic transmitting and receiving circuit, the direction control circuit of steering gear, the wireless communication circuit. Liquid crystal display circuit and acoustooptic alarm circuit. According to the logic relation of the ranging system, the flow chart is compiled and the software is implemented by C language. In order to improve the accuracy of ultrasonic propagation time, the Kalman filter algorithm is used to estimate the next level height and adjust the measuring range automatically, when only one ultrasonic sensor is used, The ultrasonic velocity is accurately measured and calculated by combining the standard baffle and the steering gear to calculate the height of the measured liquid surface. Finally, the ultrasonic ranging system is measured and the detection results and error elements are analyzed. The system has been simulated and measured, which shows that all the technical indexes meet the predetermined requirements, and the system has the advantages of simple hardware structure, low cost, high accuracy and so on. It also realizes the real-time display of liquid level height and the dual alarm function when the threshold value is reached or exceeded.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB559

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