发布时间 : 星期一 文章毕业论文，基于单片机的超声波检测系统更新完毕开始阅读f3109a67f5335a8102d22045
XXXXXX毕业论文
蓄电池电解液比重的超声波测量系统设计
学 院 专 业 班 级 学 籍 号 姓 名 指导教师
XXXXX大 学
20XX年X月X日
XXX大学学士学位论文
摘 要
目前，对开口式铅酸蓄电池电解液比重的测量大部分采用吸式或者浮式比重计，这两种比重计都是利用浮子在电解液中所受的浮力来测量电解液的比重，由于电解液的粘滞性很大，在实际的测量中，浮子常常被粘附在器壁上，从而造成读数的不准确，而且这种方法既费时费力，而且效率不高，不能满足实时在线测量的要求。
本系统采用超声波传感器作为测量媒介，利用MSP430FG4619单片机作为控制核心。发射单元中，由2.00MHz晶振发出的方波脉冲经分频电路、推挽电路、场效应管放大电路后驱动发射换能器；在接收单元，超声波经液体传播后被接收换能器所接收，由于接收到的方波脉冲信号很微弱，因此加了两级运算放大，又经过比较电路输出标准的方波信号进入单片机的中断。由单片机控制双D触发器CD4013发射固定周期的驱动脉冲，当接收单元接收到信号，经比较器LMll9将此接收信号传送到单片机，最后由单片机进行运算数据处理，从而得到电解液的比重。
关键词：蓄电池电解液；超声波；换能器；单片机；比重
i XXX大学XXXXXX学院
XXX大学学士学位论文
ABSTRACT
At Present,the proportion of open-type lead-acid storage battery electrolyte measurement uses the type of suction or the floating hydrometer majority,the hydrometers of these two are the using of float in the electrolyte to measure the sustained buoyancy of the proportion of the electrolyte,due to electrolysis viscous fluid is high,the actual measurement,often float wall adhesion in the browser，resulting in inaccurate readings,so this method is time-consuming effort,and inefficient,can not meet the real-time online measurement requirements.
This system uses ultrasonic sensors as the measurement media,using single-chip microcomputer MSP430FG4619 as the control core. In the unit of launch,2.00MHz crystal oscillator sends out the square-wave pulse,the pulse drives the transmitting transducer through the frequency dividing circuit,the push-pull circuit and the FET amplifying circuit. In the unit of receiver,the receiving transducer receives the ultrasonic wave after spreading the liquid,as a result of the receiving square wave pulse is so weak,it adds two levels of operational amplifier and comparator to standard square-wave signal.Controls double D integrated circuit trigger CD4013 to launch the fixed cycle,when the reception unit receives the launch signal,the LMll9 comparator to transmit the signal to the single-chip. Experiments will be set through the time and the proportion of the spread of fitted values,thus getting the proportion of electrolyte.
Key Words: Battery Electrolyte; Ultrasonic Wave; Transducer; Single-chip; Specific Gravity
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XXX大学学士学位论文
目 录
摘 要 ............................................................................................................................................ i ABSTRACT .................................................................................................................................... ii
第1章 绪论 ............................................................................................................................... 1
1.1 课题的来源、目的和意义 ............................................................................................... 1 1.2 研究现状 ........................................................................................................................... 1 1.3 本文的研究内容及结构 ................................................................................................... 4 第2章 总体设计方案 ................................................................................................................. 5
2.1 铅酸蓄电池工作原理 ....................................................................................................... 5 2.2 超声波换能器 ................................................................................................................... 6 2.3 超声波测量比重的工作原理 ........................................................................................... 9 2.4 超声波测量比重的硬件要求 ......................................................................................... 10
2.4.1 发射部分 ............................................................................................................... 11 2.4.2 接收部分 ............................................................................................................... 11 2.4.3 单片机控制部分 ................................................................................................... 12 2.4.4 温度补偿部分 ....................................................................................................... 12 2.5 超声波测量比重的软件要求 ......................................................................................... 12 2.6 本章小结 ......................................................................................................................... 13 第3章 超声波比重测量的硬件设计 ....................................................................................... 14
3.1 发射电路单元 ................................................................................................................. 14
3.1.1 现有的发射驱动电路 ........................................................................................... 14 3.1.2 本系统的发射驱动电路 ....................................................................................... 16 3.2 接收电路单元 ................................................................................................................. 18
3.2.1 运算放大电路 ....................................................................................................... 18 3.2.2 比较电路 ............................................................................................................... 21 3.3单片机的外围电路 .......................................................................................................... 22
3.2.1 时钟电路 ............................................................................................................... 22 3.2.2 复位电路 ............................................................................................................... 24 3.2.3 温度补偿电路 ....................................................................................................... 25 3.2.4 显示电路 ............................................................................................................... 26 3.4 电源电路 ......................................................................................................................... 28
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