摘要液位计作为一种实时监测液位的工具被运用于工业生产的许多领域。早期的 机械式液位计一定程度上解放了生产力，代替了人工液位测量。但是在现如今信 息化的社会里，信息更新速度慢，精度低等短板也使其远远不能满足生产要求。 液位计电子化也成为其必然的发展趋势。单片机已出现半个世纪，发展越来越成 熟。将单片机与超声波结合在一起应用于液位测量领域将很好的解决传统液位计 的所面临的问题，实现液位计的自动化，可移动化，信息化，互联网化，并大大 提高液位计的测量精度。82240

随着人们生活水平的提高，私家汽车进入千家万户。鉴于汽车发展存在巨大 的经济潜力，与汽车相关的配套设备发展迅速。本课题的研究内容是设计一个基 于单片机的超声波自动测量物体液位系统，其应用场景为汽车油箱的油量监测。

本系统的硬件部分主要由 STC90C51RC 单片机最小系统，HC-SR04 超声波模 块，BT-HC05 蓝牙模块，DS18B20 温度传感器组成。STC90C51RC 单片机最小系统 是系统的核心，用于控制超声波模块测距，蓝牙模块用于与上位机通信，温度传 感器用于校正数据。本系统的软件部分主要包括单片机程序与上位机程序。本系 统利用超生波传输距离与时间的关系来测液位。本系统设计了温度补偿电路，通 过实时的温度采集来提高了的精确度。相对传统液位监测系统本系统具有非接触 性，易控制，精确度高，自动化等优点。 

毕业论文关键词：单片机，超声波，液位测量

Abstract As a real-time monitoring liquid level tool, liquidometer is applied in many fields of industrial production。 The early mechanical liquidometer emancipates productivity to some extent and substitutes manual liquid level measurement。 However, in current informatized society, the low speed of information updating and low precision, etc。 makes it far from meeting the production requirement。 Liquidometer electronization becomes the inevitable development trend。 Single chip microcomputer has appeared for half a century and the development is increasingly mature。 The  application of single chip microcomputer combined with ultrasound wave to liquid level measurement will solve the problems that traditional liquidometer encounters, realize automation, removability, informatization and internet of liquidometer and enhance the measurement precision of liquidometer greatly。

With the growth in the living standard of people, private car enters thousands of households。 Whereas there is giant economic potential for the development of car, and the related matching devices of car develops rapidly, the research content of the paper is to design a system that measures the liquid level of substance with ultrasound wave automatically based on the single chip microcomputer。 The application scene is the oil level monitoring of car oil tank。

The hardware part of the system is mainly made up by minimum system of STC90C51RC single chip microcomputer, HC-SR04 ultrasonic wave module, BT-HC05 bluetooth module and DS18B20 temperature sensor。 The minimum system of STC90C51RC single chip microcomputer is the core of the system, used for controlling the spacing of ultrasonic wave module。 The Bluetooth module is used to communicate with upper computer and the temperature sensor is used for correcting data。 The software part of the system mainly includes single chip microcomputer program and upper computer program。 The system utilizes the relationship between the transmission distance of ultrasonic wave and the time to measure the liquid level。 The system designs temperature-compensation circuit and improves precision through

real-time temperature collection。 Compared with traditional liquid monitoring system, the system has the advantages of non-touch, easy controlling, high precision, automation, etc。