基于VB语言的发动机特性曲线绘制系统研究

《自动控制原理》实践报告实验三系统频率特性曲线的绘制及系统分析熟悉利用计算机绘制系统伯德图、乃奎斯特曲线的方法，并利用所绘制图形分析系统性能。

一、实验目的1．熟练掌握使用MATLAB软件绘制Bode图及Nyquist曲线的方法；2．进一步加深对Bode图及Nyquist曲线的了解；3．利用所绘制Bode图及Nyquist曲线分析系统性能。

二、主要实验设备及仪器实验设备：每人一台计算机奔腾系列以上计算机，配置硬盘≥2G，内存≥64M。

实验软件：WINDOWS操作系统（WINDOWS XP 或WINDOWS 2000），并安装MATLAB 语言编程环境。

三、实验内容已知系统开环传递函数分别为如下形式， （1）)2)(5(50)(++=s s s G （2）)15)(5(250)(++=s s s s G（3）210()(21)s G s s s s +=++ （4）)12.0)(12(8)(++=s s s s G （5）23221()0.21s s G s s s s ++=+++ （6）)]105.0)125.0)[(12()15.0(4)(2++++=s s s s s s G 1．绘制其Nyquist 曲线和Bode 图，记录或拷贝所绘制系统的各种图形； 1、 程序代码： num=[50];den=conv([1 5],[1 2]); bode(num,den)num=[50];den=conv([1 5],[1 2]); nyquist(num,den)-80-60-40-20020M a g n i t u d e (d B)10-210-110101102103-180-135-90-450P h a s e (d e g )Bode DiagramFrequency (rad/sec)-1012345-4-3-2-11234Nyquist DiagramReal AxisI m a g i n a r y A x i s2、 程序代码： num=[250];den=conv(conv([1 0],[1 5]),[1 15]); bode(num,den)num=[250];den=conv(conv([1 0],[1 5]),[1 15]);-150-100-5050M a g n i t u d e (d B )10-110101102103-270-225-180-135-90P h a s e (d e g )Bode DiagramFrequency (rad/sec)nyquist(num,den)3、 程序代码： num=[1 10];den=conv([1 0],[2 1 1]); bode(num,den)-150-100-50050100M a g n i t u d e (d B)10-210-110101102103-270-225-180-135-90P h a s e (d e g )Bode DiagramFrequency (rad/sec)-1-0.9-0.8-0.7-0.6-0.5-0.4-0.3-0.2-0.10-15-10-551015System: sys Real: -0.132Imag: -0.0124Frequency (rad/sec): -10.3Nyquist DiagramReal AxisI m a g i n a r y A x i snum=[1 10];den=conv([1 0],[2 1 1]); nyquist(num,den)-25-20-15-10-5-200-150-100-5050100150200Nyquist DiagramReal AxisI m a g i n a r y A x i s-100-5050100M a g n i t u d e (d B )10-210-110101102-270-225-180-135-90P h a s e (d e g )Bode DiagramFrequency (rad/sec)4、 程序代码： num=[8];den=conv(conv([1 0],[2 1]),[0.2 1]); bode(num,den)-18-16-14-12-10-8-6-4-20-250-200-150-100-50050100150200250Nyquist DiagramReal AxisI m a g i n a r y A x i snum=[8];den=conv(conv([1 0],[2 1]),[0.2 1]); nyquist(num,den)5、 程序代码： num=[1 2 1]; den=[1 0.2 1 1]; bode(num,den)num=[1 2 1];den=[1 0.2 1 1]; nyquist(num,den)-40-30-20-10010M a g n i t u d e (d B )10-210-110101102-360-270-180-90P h a s e (d e g )Bode DiagramFrequency (rad/sec)-2.5-2-1.5-1-0.500.51 1.5-3-2-1123Nyquist DiagramReal AxisI m a g i n a r y A x i s-100-5050100M a g n i t u d e (d B )10-210-110101102-270-225-180-135-90P h a s e (d e g )Bode DiagramFrequency (rad/sec)6、 num=[2 4];den=conv(conv([1 0],[2 1]),[0.015625 0.05 1]); bode(num,den)num=[2 4];den=conv(conv([1 0],[2 1]),[0.015625 0.05 1]); nyquist(num,den)2．利用所绘制出的Nyquist 曲线及Bode 图对系统的性能进行分析：（1）利用以上任意一种方法绘制的图形判断系统的稳定性； 由Nyquist 曲线判断系统的稳定性，Z=P-2N 。

计算机实习二需求分析：函数曲线动态绘制使用面向对象设计环境，编程实现函数曲线的自动绘制。

程序功能是：根据选择的演示函数，允许用户输入参数，然后动态用不同颜色绘制出相应函数曲线。

在用户没有做出其他选择之前，一直重复动态演示曲线绘制过程。

程序设计：1，对面向对象设计环境的认识：第一次接触面向对象设计环境，觉得和C语言和汇编语言有很大差别，不是给你一个界面一条条代码往下写，而是给出很多的控件备选，在这些控件的代码添写处写该孔件所要执行的功能，很多控件是相互联系的，一个控件会启用其他一个或几个控件的功能。

还要设计一个合理的外观，通过设置相应的属性选项设计界面。

但是编程的思想和以前学习的语言是完全一样的，数据类型，定义，顺序，循环，选择结构的设计都和其他语言没太大分别，所以学习起来并不困难。

2，程序构思；把要绘制的函数放在一个列表框中，用时钟的启用和停止控制图像的都态绘制。

选择列表框中的一个函数，对应的一个时钟启用，其他的时钟禁用，在时钟控件的代码填写处写图像绘制的代码，用RGB 函数产生随机颜色。

直线用两点法绘图，其他的用描点法绘图，用FOR循环产生X值，再根据函数公式计算出Y值。

使用全局变量，因为每次只绘一个函数的图，所以全部函数可以用同样的变量，每次绘图给变量付值即可。

该学生毕业设计中经过老师的指导能及时纠正自己的行为，端正学习态度。

通过指导和自学，对所承担的任务进行了实施，结果较好。

报告中因为没有按指导要求使用画图软件，导致流程图不规范。

语言不规范。

结果得分：中 批改老师：章小莉 2006．9．29程序代码和注释Dim a, b, c, d As Single ‘定义单精度的通用变量Private Sub cancel_Click()Unload Me 退出程序End SubPrivate Sub Form_Load() ‘在列表狂中显示函数信息List1.AddItem "y=ax+b" ‘在列表狂中显示函数信息List1.AddItem "y=ax^2+bx+c" ‘在列表狂中显示函数信息List1.AddItem "y=asin(bx+c)+d" ‘在列表狂中显示函数信息List1.AddItem "y=acos(bx+c)+d" ‘在列表狂中显示函数信息List1.AddItem "y=x^a" ‘在列表狂中显示函数信息List1.AddItem "y=a^x" ‘在列表狂中显示函数信息List1.AddItem "y=loga^x" ‘在列表狂中显示函数信息List1.AddItem "y=tan(ax+b)" ‘在列表狂中显示函数信息List1.AddItem "y=cot(ax+b)" ‘在列表狂中显示函数信息End SubPrivate Sub lt1_Click() ‘使所有时钟停止，即停止绘图Timer1.Interval = 0Timer2.Interval = 0Timer3.Interval = 0Timer4.Interval = 0Timer5.Interval = 0Timer6.Interval = 0Timer7.Interval = 0Timer8.Interval = 0Timer9.Interval = 0End SubPrivate Sub lt2_Click()If List1.ListIndex = 0 Thena = InputBox("直线参数输入", "请输入系数a", 0)b = InputBox("直线参数输入", "请输入系数b", 0)Timer1.Interval = 1000 ‘当选择第一个函数时开启时钟一End IfIf List1.ListIndex = 1 Thena = InputBox("抛物线参数输入", "请输入系数a", 0)b = InputBox("抛物线参数输入", "请输入系数b", 0)c = InputBox("抛物线参数输入", "请输入系数c", 0)Timer2.Interval = 1000 ‘当选择第二个函数时开启时钟二End IfIf List1.ListIndex = 2 Thena = InputBox("正弦线参数输入", "请输入系数a", 0)b = InputBox("正弦线参数输入", "请输入系数b", 0)c = InputBox("正弦线参数输入", "请输入系数c", 0)d = InputBox("正弦线参数输入", "请输入系数d", 0)Timer3.Interval = 1000 ‘当选择第三个函数时开启时钟三End IfIf List1.ListIndex = 3 Thena = InputBox("余弦线参数输入", "请输入系数a", 0)b = InputBox("余弦线参数输入", "请输入系数b", 0)c = InputBox("余弦线参数输入", "请输入系数c", 0)d = InputBox("余弦线参数输入", "请输入系数d", 0)Timer4.Interval = 1000 ‘当选择第四个函数时开启时钟四End IfIf List1.ListIndex = 4 Thena = InputBox("幂函数参数输入", "请输入系数a", 0)Timer5.Interval = 1000 ‘当选择第五个函数时开启时钟五End IfIf List1.ListIndex = 5 Thena = InputBox("指数函数参数输入", "请输入系数a", 0)Timer6.Interval = 1000 ‘当选择第六个函数时开启时钟六End IfIf List1.ListIndex = 6 Thena = InputBox("对数函数参数输入", "请输入系数a", 0)Timer7.Interval = 1000 ‘当选择第七个函数时开启时钟七End IfIf List1.ListIndex = 7 Thena = InputBox("正切函数参数输入", "请输入系数a", 0)b = InputBox("正切函数参数输入", "请输入系数b", 0)Timer8.Interval = 1000 ‘当选择第八个函数时开启时钟八End IfIf List1.ListIndex = 8 Thena = InputBox("余切函数参数输入", "请输入系数a", 0)b = InputBox("余切函数参数输入", "请输入系数b", 0)Timer9.Interval = 1000 ‘当选择第九个函数时开启时钟九End IfEnd SubPrivate Sub lt3_Click()Picture1.Cls ‘清屏End SubPrivate Sub Text1_Change()End SubPrivate Sub Timer1_Timer()Picture1.ClsPicture1.Scale (-10, 10)-(10, -10) ‘定义坐标red = Rnd * 255green = Rnd * 255blue = Rnd * 255Intcolor = RGB(red, green, blue) ‘产生随机颜色X1 = -10X2 = 10Y1 = a * X1 + b ‘用已知的X值计算Y值Y2 = a * X2 + bPicture1.Line (-10, 0)-(10, 0)Picture1.Line (0, 10)-(0, -10) ‘画坐标Picture1.Line (X1, Y1)-(X2, Y2), Intcolor ‘用随机颜色画图End SubPrivate Sub Timer2_Timer()Picture1.Cls ‘清屏Picture1.Scale (-10, 10)-(10, -10) ‘定义坐标red = Rnd * 255green = Rnd * 255blue = Rnd * 255Intcolor = RGB(red, green, blue) ‘产生随机颜色For i = 0 To 20 Step 0.01 ‘循环产生等步长的很多X值X1 = -10 + iY1 = a * X1 ^ 2 + b * X1 + c ‘用已知的X值计算Y值Picture1.Line (-10, 0)-(10, 0)Picture1.Line (0, 10)-(0, -10) ‘画坐标Picture1.PSet (X1, Y1), Intcolor ‘用随机颜色画点Next iEnd SubPrivate Sub Timer3_Timer()Picture1.Cls ‘清屏Picture1.Scale (-10, 10)-(10, -10) ‘定义坐标red = Rnd * 255green = Rnd * 255blue = Rnd * 255Intcolor = RGB(red, green, blue) ‘产生随机颜色For i = 0 To 20 Step 0.01 ‘循环产生等步长的很多X值X1 = -10 + iY1 = a * Sin(b * X1 + c) + d ‘用已知的X值计算Y值Picture1.Line (-10, 0)-(10, 0)Picture1.Line (0, 10)-(0, -10) ‘画坐标Picture1.PSet (X1, Y1), Intcolor ‘用随机颜色画点Next iEnd SubPrivate Sub Timer4_Timer()Picture1.Cls ‘清屏Picture1.Scale (-10, 10)-(10, -10) ‘定义坐标red = Rnd * 255green = Rnd * 255blue = Rnd * 255Intcolor = RGB(red, green, blue) ‘产生随机颜色For i = 0 To 20 Step 0.01 ‘循环产生等步长的很多X值X1 = -10 + iY1 = a * Cos(b * X1 + c) + d ‘用已知的X值计算Y值Picture1.Line (-10, 0)-(10, 0)Picture1.Line (0, 10)-(0, -10) ‘画坐标Picture1.PSet (X1, Y1), Intcolor ‘用随机颜色画点Next iEnd SubPrivate Sub Timer5_Timer()Picture1.Cls ‘清屏Picture1.Scale (-10, 10)-(10, -10) ‘定义坐标red = Rnd * 255green = Rnd * 255blue = Rnd * 255Intcolor = RGB(red, green, blue) ‘产生随机颜色For i = 0 To 20 Step 0.01 ‘循环产生等步长的很多X值X1 = -10 + iY1 = X1 ^ a ‘用已知的X值计算Y值Picture1.Line (-10, 0)-(10, 0)Picture1.Line (0, 10)-(0, -10) ‘画坐标Picture1.PSet (X1, Y1), Intcolor ‘用随机颜色画点Next iEnd SubPrivate Sub Timer6_Timer()Picture1.Cls ‘清屏Picture1.Scale (-10, 10)-(10, -10) ‘定义坐标red = Rnd * 255green = Rnd * 255blue = Rnd * 255Intcolor = RGB(red, green, blue) ‘产生随机颜色For i = 0 To 20 Step 0.01 ‘循环产生等步长的很多X值X1 = -10 + iY1 = a ^ X1 ‘用已知的X值计算Y值Picture1.Line (-10, 0)-(10, 0)Picture1.Line (0, 10)-(0, -10) ‘画坐标Picture1.PSet (X1, Y1), Intcolor ‘用随机颜色画点Next iEnd SubPrivate Sub Timer7_Timer()Picture1.Cls ‘清屏Picture1.Scale (-10, 10)-(10, -10) ‘定义坐标red = Rnd * 255green = Rnd * 255blue = Rnd * 255Intcolor = RGB(red, green, blue) ‘产生随机颜色For i = 0.01 To 20 Step 0.01 ‘循环产生等步长的很多X值X1 = 0 + iY1 = Log(X1) / Log(a) ‘用已知的X值计算Y值Picture1.Line (-10, 0)-(10, 0)Picture1.Line (0, 10)-(0, -10) ‘画坐标Picture1.PSet (X1, Y1), Intcolor ‘用随机颜色画点Next iEnd SubPrivate Sub Timer8_Timer()Picture1.Cls ‘清屏Picture1.Scale (-10, 10)-(10, -10) ‘定义坐标red = Rnd * 255green = Rnd * 255blue = Rnd * 255Intcolor = RGB(red, green, blue) ‘产生随机颜色For i = 0 To 20 Step 0.001 ‘循环产生等步长的很多X值X1 = -10 + iY1 = Tan(a * X1 + b) ‘用已知的X值计算Y值Picture1.Line (-10, 0)-(10, 0)Picture1.Line (0, 10)-(0, -10) ‘画坐标Picture1.PSet (X1, Y1), Intcolor ‘用随机颜色画点Next iEnd SubPrivate Sub Timer9_Timer()Picture1.Cls ‘清屏Picture1.Scale (-10, 10)-(10, -10) ‘定义坐标red = Rnd * 255green = Rnd * 255blue = Rnd * 255Intcolor = RGB(red, green, blue) ‘产生随机颜色For i = 0 To 20 Step 0.001 ‘循环产生等步长的很多X值X1 = -9.9995 + iY1 = 1 / Tan(a * X1 + b) ‘用已知的X值计算Y值Picture1.Line (-10, 0)-(10, 0)Picture1.Line (0, 10)-(0, -10) ‘画坐标Picture1.PSet (X1, Y1), Intcolor ‘用随机颜色画点Next iEnd Sub使用说明：双击启动程序，在列表中选一个函数，点击开始绘图按钮，根据提示输入参数，就会自动用随机颜色画图，每秒画一次，单击一下“停止绘图”，即可使画图停止，保留最后一次的图型，单击一下“清屏”，就可以把屏幕清理干净。

基于MATLAB基础上的发动机万有特性曲线的建立杨丽娟;赵丹平【摘要】发动机性能的好坏直接影响着整车运行的平顺性、安全性、稳定性等,要全面评价发动机性能,万有特性曲线则是一个很好的工具.万有特性曲线是以发动机转速为横坐标,以扭矩或平均有效压力为纵坐标,在坐标系内画出等燃油消耗率曲线和等功率曲线[1].绘制万有特性曲线的方法有很多种,MATLAB语言是其中之一.本文利用强大的MATLAB绘图工具,绘制了发动机的万有特性曲线,经分析,该方法是一个有效的精确度较高的方法.【期刊名称】《交通节能与环保》【年(卷),期】2010(000)001【总页数】3页(P32-33,48)【关键词】MATLAB;发动机;万有特性【作者】杨丽娟;赵丹平【作者单位】内蒙古工业大学,内蒙古,赤峰,010051;内蒙古工业大学,内蒙古,赤峰,010051【正文语种】中文0 引言发动机是汽车的动力源，发动机性能的好坏直接影响着整车的动力性与经济性。

汽车的运行工况是个随机的过程，受到很多因素的影响，如道路条件、交通流量、气候条件以及汽车自身技术性能的变化等等。

在所有的运行工况下，发动机都应能够与传动系实现最佳匹配，以使整车动力性、经济性、排放性和噪声污染等方面均处于最佳状态。

然而，对发动机性能的分析与研究是保证整车性能达到最佳的重要前提。

MATLAB语言是一个功能强大的仿真软件，可以完成复杂的数学运算，实现对动态系统的建模仿真等，在工程计算中应用非常广泛。

本文利用MATLAB的强大的绘图功能，建立了发动机的输出转矩模型、油耗模型及万有特性曲线。

通过输出转矩模型，由当前发动机节气门开度及转速既可得到与之相对应的发动机的转出转矩，从而为分析发动机性能奠定基础；发动机油耗模型反应了其有效燃油消耗率与转速和转矩之间的关系，发动机在不同工况下运行时，由此模型既可得到不同工况下发动机的比油耗，从而为分析整车燃油经济性提供数据支持；万有特性曲线是在由发动机转速和转矩构成的坐标系内，绘制出等油耗曲线、等功率曲线、外特性曲线等，通过万有特性曲线既可较全面地了解发动机在不同工况下的性能指标。

3.2 实验记录（核心代码及调试过程）1.核心代码：'.............驱动力与行驶阻力平衡图Private Sub Command1_Click()Picture1.DrawWidth = 1Picture1.ClsDim i, j, n As IntegerDim Ft, Ff, Fw, Umax, Uumax As SinglePicture1.Scale (-20, 18000)-(150, -2000)Picture1.Line (0, 0)-(125, 0): Picture1.Line (0, 0)-(0, 16000)Picture1.CurrentX = 125: Picture1.CurrentY = -300: Picture1.Print "Ua(km/h)"Picture1.CurrentX = 125: Picture1.CurrentY = 192: Picture1.Print "→"Picture1.CurrentX = 5: Picture1.CurrentY = 16000: Picture1.Print "F/N"Picture1.CurrentX = -2: Picture1.CurrentY = 16000: Picture1.Print "↑"Picture1.CurrentX = -5: Picture1.CurrentY = -1: Picture1.Print "0"For i = 20 To 120 Step 20Picture1.Line (i, 0)-(i, 200)Picture1.CurrentX = i - 5: Picture1.CurrentY = -10: Picture1.Print iNext iFor i = 1000 To 15000 Step 1000Picture1.Line (0, i)-(1.5, i)Picture1.CurrentX = -15: Picture1.CurrentY = i + 50: Picture1.Print iNext iPicture1.DrawWidth = 2For n = 600 To 4000Tq = -19.313 + 295.27 * (n / 1000) - 165.44 * (n / 1000) ^ 2 + 40.874 * (n / 1000) ^ 3 - 3.8445 * (n / 1000) ^ 4For j = 1 To 5Ft = Tq * i0 * ηt * x(j) / rFf = f * 9.8 * mUa = 0.377 * r * n / (i0 * x(j))Fw = 0.5 * 1.2258 * ca * (Ua / 3.6) ^ 2Picture1.Circle (Ua, Ft), 0.1, vbBluePicture1.Circle (Ua, (Ff + Fw)), 0.1, vbRedUmax = UmaxIf Ua > Umax ThenUmax = UaElseUmax = UmaxEnd IfNext jNext nUumax = CInt(Umax * 100) / 100Picture1.CurrentX = 40: Picture1.CurrentY = 16000: Picture1.Print "最高车速为："; Uumax; "km/h"End Sub'.............爬坡度图Private Sub Command2_Click()Picture1.ClsPicture1.DrawWidth = 1Dim i, j, n As IntegerDim xx, Ff, Fw, Ft, ii, imax, iimax As SinglePicture1.Scale (-20, 70)-(150, -10)Picture1.Line (0, 0)-(125, 0): Picture1.Line (0, 0)-(0, 60)Picture1.CurrentX = 125: Picture1.CurrentY = -3: Picture1.Print "Ua(km/h)"Picture1.CurrentX = 125: Picture1.CurrentY = 0.85: Picture1.Print "→"Picture1.CurrentX = 5: Picture1.CurrentY = 60: Picture1.Print "i(%)"Picture1.CurrentX = -2: Picture1.CurrentY = 60: Picture1.Print "↑"Picture1.CurrentX = -5: Picture1.CurrentY = -1: Picture1.Print "0"For i = 20 To 120 Step 20Picture1.Line (i, 0)-(i, 1)Picture1.CurrentX = i - 5: Picture1.CurrentY = -1: Picture1.Print iNext iFor i = 10 To 50 Step 10Picture1.Line (0, i)-(2, i)Picture1.CurrentX = -10: Picture1.CurrentY = i + 1: Picture1.Print iNext iPicture1.DrawWidth = 2For n = 600 To 4000Tq = -19.313 + 295.27 * (n / 1000) - 165.44 * (n / 1000) ^ 2 + 40.874 * (n / 1000) ^ 3 - 3.8445 * (n / 1000) ^ 4For j = 1 To 5Ft = Tq * i0 * ηt * x(j) / rFf = f * 9.8 * mUa = 0.377 * r * n / (i0 * x(j))Fw = 0.5 * 1.2258 * ca * (Ua / 3.6) ^ 2xx = (Ft - Ff - Fw) / (9.8 * m)α = Atn(xx / Sqr(1 - xx * xx))ii = 100 * Tan(α)If ii > 0 ThenPicture1.Circle (Ua, ii), 0.1, vbBlueEnd Ifimax = imaxIf ii > imax Thenimax = iiElseimax = imaxEnd IfNext jNext niimax = CInt(imax * 100) / 100Picture1.CurrentX = 40: Picture1.CurrentY = 50: Picture1.Print "最大爬坡度为："; iimax; "%" End Sub'...........动力特性图Private Sub Command3_Click()Picture1.DrawWidth = 1Picture1.ClsDim i, j, n As IntegerDim Ft, Fw, D As SinglePicture1.Scale (-20, 90)-(150, -10)Picture1.Line (0, 0)-(125, 0): Picture1.Line (0, 0)-(0, 85)Picture1.CurrentX = 125: Picture1.CurrentY = -3: Picture1.Print "Ua(km/h)"Picture1.CurrentX = 125: Picture1.CurrentY = 0.9: Picture1.Print "→"Picture1.CurrentX = 5: Picture1.CurrentY = 85: Picture1.Print "D"Picture1.CurrentX = -2: Picture1.CurrentY = 85: Picture1.Print "↑"Picture1.CurrentX = -5: Picture1.CurrentY = -1: Picture1.Print "0"For i = 20 To 120 Step 20Picture1.Line (i, 0)-(i, 1)Picture1.CurrentX = i - 5: Picture1.CurrentY = -1: Picture1.Print iNext iFor i = 20 To 80 Step 20Picture1.Line (0, i)-(2, i)Picture1.CurrentX = -10: Picture1.CurrentY = i + 1: Picture1.Print "0"; i / 200Next iPicture1.DrawWidth = 2For n = 600 To 4000For j = 1 To 5Tq = -19.313 + 295.27 * (n / 1000) - 165.44 * (n / 1000) ^ 2 + 40.874 * (n / 1000)^ 3 - 3.8445 * (n / 1000) ^ 4Ft = Tq * i0 * ηt * x(j) / rUa = 0.377 * r * n / (i0 * x(j))Fw = 0.5 * 1.2258 * ca * (Ua / 3.6) ^ 2D = 200 * (Ft - Fw) / (m * 9.8)If D > 0 ThenPicture1.Circle (Ua, D), 0.1, vbBlueEnd IfNext jNext nEnd Sub'.............功率平衡图Private Sub Command4_Click()Picture1.DrawWidth = 1Picture1.ClsDim i, j, n As IntegerDim Pe, Pf, Pw As SinglePicture1.Scale (-20, 80)-(150, -10)Picture1.Line (0, 0)-(125, 0): Picture1.Line (0, 0)-(0, 75)Picture1.CurrentX = 125: Picture1.CurrentY = -3: Picture1.Print "Ua(km/h)" Picture1.CurrentX = 125: Picture1.CurrentY = 0.9: Picture1.Print "→"Picture1.CurrentX = 5: Picture1.CurrentY = 75: Picture1.Print "Pe/kw"Picture1.CurrentX = -2: Picture1.CurrentY = 75: Picture1.Print "↑"Picture1.CurrentX = -5: Picture1.CurrentY = -1: Picture1.Print "0"For i = 20 To 120 Step 20Picture1.Line (i, 0)-(i, 1)Picture1.CurrentX = i - 5: Picture1.CurrentY = -1: Picture1.Print iNext iFor i = 10 To 70 Step 10Picture1.Line (0, i)-(2, i)Picture1.CurrentX = -10: Picture1.CurrentY = i + 1: Picture1.Print iNext iPicture1.DrawWidth = 2For n = 600 To 4000For j = 1 To 5Tq = -19.313 + 295.27 * (n / 1000) - 165.44 * (n / 1000) ^ 2 + 40.874 * (n / 1000) ^ 3 - 3.8445 * (n / 1000) ^ 4Pe = Tq * n / 9550Ua = 0.377 * r * n / (i0 * x(j))Pf = (m * f * Ua / 3600) / ηtPw = (ca * Ua ^ 3 / 76140) / ηtPicture1.Circle (Ua, Pe), 0.1, vbBluePicture1.Circle (Ua, (Pf + Pw)), 0.1, vbRedNext jNext nEnd Sub'...........外特性曲线Private Sub Command5_Click()Picture1.DrawWidth = 1Picture1.ClsDim i, n As IntegerDim Pe As SinglePicture1.Scale (-400, 250)-(5000, -20)Picture1.Line (0, 0)-(4500, 0): Picture1.Line (0, 0)-(0, 200)Picture1.CurrentX = 4300: Picture1.CurrentY = -3: Picture1.Print "n(r/min)"Picture1.CurrentX = 4500: Picture1.CurrentY = 3: Picture1.Print "→"Picture1.CurrentX = 100: Picture1.CurrentY = 200: Picture1.Print "Ttq(N*m)"Picture1.CurrentX = 100: Picture1.CurrentY = 80: Picture1.Print "Pe(kw)"Picture1.CurrentX = -60: Picture1.CurrentY = 205: Picture1.Print "↑"Picture1.CurrentX = -5: Picture1.CurrentY = -1: Picture1.Print "0"For i = 500 To 4000 Step 500Picture1.Line (i, 0)-(i, 3)Picture1.CurrentX = i - 200: Picture1.CurrentY = -1: Picture1.Print iNext iFor i = 20 To 180 Step 20Picture1.Line (0, i)-(50, i)Picture1.CurrentX = -300: Picture1.CurrentY = i + 3: Picture1.Print iNext iPicture1.DrawWidth = 2For n = 600 To 4000Tq = -19.313 + 295.27 * (n / 1000) - 165.44 * (n / 1000) ^ 2 + 40.874 * (n / 1000) ^ 3 - 3.8445 * (n / 1000) ^ 4Pe = Tq * n / 9550Picture1.Circle (n, Pe), 2, vbRedPicture1.Circle (n, Tq), 2, vbBlueNext nEnd Sub2.数据图表：驱动力与行驶阻力平衡图：动力特性图：爬坡度图：发动机外特性曲线：发动机功率平衡图：3.2 实验记录（核心代码及调试过程）1.核心代码：'.........加速度的倒数曲线Private Sub Command7_Click()Picture1.DrawWidth = 1Picture1.ClsDim i, j, n As IntegerDim Ff, Ft, Fw, a, δ As SinglePicture1.Scale (-20, 160)-(150, -10)Picture1.Line (0, 0)-(125, 0): Picture1.Line (0, 0)-(0, 150)Picture1.CurrentX = 125: Picture1.CurrentY = -3: Picture1.Print "Ua(km/h)"Picture1.CurrentX = 125: Picture1.CurrentY = 1.8: Picture1.Print "→"Picture1.CurrentX = 5: Picture1.CurrentY = 150: Picture1.Print "1/a"Picture1.CurrentX = -2: Picture1.CurrentY = 150: Picture1.Print "↑"Picture1.CurrentX = -5: Picture1.CurrentY = -1: Picture1.Print "0"For i = 20 To 120 Step 20Picture1.Line (i, 0)-(i, 1.5)Picture1.CurrentX = i - 5: Picture1.CurrentY = -1: Picture1.Print iNext iFor i = 10 To 140 Step 10Picture1.Line (0, i)-(2, i)Picture1.CurrentX = -10: Picture1.CurrentY = i + 1: Picture1.Print i / 10Next iPicture1.DrawWidth = 2For n = 600 To 4000For j = 1 To 5Tq = -19.313 + 295.27 * (n / 1000) - 165.44 * (n / 1000) ^ 2 + 40.874 * (n / 1000) ^ 3 - 3.8445 * (n / 1000) ^ 4Ft = Tq * i0 * ηt * x(j) / rUa = 0.377 * r * n / (i0 * x(j))Fw = 0.5 * 1.2258 * ca * (Ua / 3.6) ^ 2Ff = f * 9.8 * mδ = 1 + Iw / (m * r ^ 2) + If1 * x(j) ^ 2 * i0 ^ 2 * ηt / (m * r ^ 2) a = (Ft - Ff - Fw) / (δ * m)If a > 0 ThenPicture1.Circle (Ua, 10 / a), 0.1, vbBlueEnd IfNext jNext nEnd Sub'..............直接挡加速时间曲线Private Sub Command8_Click()Picture1.DrawWidth = 1Picture1.ClsDim i, n As IntegerDim Ff, Ft, Fw, a, δ, t, tt As SinglePicture1.Scale (-10, 90)-(60, -10)Picture1.Line (0, 0)-(55, 0): Picture1.Line (0, 0)-(0, 75)Picture1.CurrentX = 53: Picture1.CurrentY = -3: Picture1.Print "t(s)"Picture1.CurrentX = 55: Picture1.CurrentY = 0.9: Picture1.Print "→"Picture1.CurrentX = 2: Picture1.CurrentY = 75: Picture1.Print "Ua(km/h)"Picture1.CurrentX = -0.7: Picture1.CurrentY = 75: Picture1.Print "↑"Picture1.CurrentX = -3: Picture1.CurrentY = -1: Picture1.Print "0"For i = 10 To 50 Step 10Picture1.Line (i, 0)-(i, 1)Picture1.CurrentX = i - 1.5: Picture1.CurrentY = -1: Picture1.Print iNext iFor i = 10 To 70 Step 10Picture1.Line (0, i)-(1, i)Picture1.CurrentX = -5: Picture1.CurrentY = i + 1: Picture1.Print it = 0For Ua = 0 To 70 Step 0.01n = Ua * i0 * x(4) / 0.377 / rIf n >= 600 ThenTq = -19.313 + 295.27 * (n / 1000) - 165.44 * (n / 1000) ^ 2 + 40.874 * (n / 1000) ^ 3 - 3.8445 * (n / 1000) ^ 4Ft = Tq * i0 * ηt * x(4) / rFw = 0.5 * 1.2258 * ca * (Ua / 3.6) ^ 2Ff = f * 9.8 * mδ = 1 + Iw / (m * r ^ 2) + If1 * x(4) ^ 2 * i0 ^ 2 * ηt / (m * r ^ 2)a = (Ft - Ff - Fw) / (δ * m)t = t + 1 * 0.01 / a / 3.6Picture1.Circle (t, Ua), 0.1, vbBlueEnd IfNext Uatt = CInt(t * 100) / 100Picture1.CurrentX = 15: Picture1.CurrentY = 80: Picture1.Print "0-70（km/h）直接挡加速时间为："; tt; "s"End Sub加速度曲线图：加速度倒数曲线：直接挡加速时间图：3.2 实验记录（核心代码及调试过程）1.核心代码'.........最高挡百公里耗油量Private Sub Command1_Click()Dim n(1 To 8), B0(1 To 8), B1(1 To 8), B2(1 To 8), B3(1 To 8), B4(1 To 8)n(1) = 815: n(2) = 1207: n(3) = 1614: n(4) = 2012: n(5) = 2603: n(6) = 3006: n(7) = 3403: n(8) = 3804B0(1) = 1326.8: B0(2) = 1354.7: B0(3) = 1284.4: B0(4) = 1122.9: B0(5) = 1141#: B0(6) = 1051.2: B0(7) = 1233.9: B0(8) = 1129.7B1(1) = -416.46: B1(2) = -303.98: B1(3) = -189.75: B1(4) = -121.59: B1(5) = -98.893: B1(6) = -73.714: B1(7) = -84.478: B1(8) = -45.291B2(1) = 72.379: B2(2) = 36.657: B2(3) = 14.524: B2(4) = 7.0035: B2(5) = 4.4763: B2(6) = 2.8593: B2(7) = 2.9788: B2(8) = 0.71113B3(1) = -5.8629: B3(2) = -2.0553: B3(3) = -0.51184: B3(4) = -0.18517: B3(5) = -0.091077: B3(6) = -0.05138: B3(7) = -0.047449: B3(8) = -0.00075215B4(1) = 0.17768: B4(2) = 0.043072: B4(3) = 0.0068164: B4(4) = 0.0018555: B4(5) = 0.00068906: B4(6) = 0.00035032: B4(7) = 0.0002823: B4(8) = -0.000038568Picture1.Scale (-10, 50)-(150, -10)Picture1.Line (0, 0)-(120, 0): Picture1.Line (0, 0)-(0, 45)Picture1.CurrentX = 120: Picture1.CurrentY = -3: Picture1.Print "Ua(km/h)"Picture1.CurrentX = 120: Picture1.CurrentY = 1: Picture1.Print "→"Picture1.CurrentX = 5: Picture1.CurrentY = 45: Picture1.Print "Qs(L/100km)"Picture1.CurrentX = -2.5: Picture1.CurrentY = 46: Picture1.Print "↑"Picture1.CurrentX = -3: Picture1.CurrentY = -1: Picture1.Print "0"For i = 20 To 100 Step 20Picture1.Line (i, 0)-(i, 1)Picture1.CurrentX = i - 6: Picture1.CurrentY = -1: Picture1.Print iNext iFor i = 10 To 40 Step 10Picture1.Line (0, i)-(3, i)Picture1.CurrentX = -12: Picture1.CurrentY = i + 1: Picture1.Print iNext ig = 3880 * 9.8f = 0.013CdA = 2.77ηt = 0.85i0 = 5.83r = 0.367Uamin = 0.377 * r * n(1) / (0.793 * i0)Qmin = 100Picture1.DrawWidth = 2For ua = Uamin To 100 Step 0.01Pe = (g * f * ua / 3600 + CdA * ua ^ 3 / 76140) / ηtnn = 0.793 * i0 * ua / (0.377 * r)For i = 1 To 7If nn >= n(i) And nn <= n(i + 1) ThenB0B0 = B0(i) + (B0(i + 1) - B0(i)) * (nn - n(i)) / (n(i + 1) - n(i)) B1B1 = B1(i) + (B1(i + 1) - B1(i)) * (nn - n(i)) / (n(i + 1) - n(i)) B2B2 = B2(i) + (B2(i + 1) - B2(i)) * (nn - n(i)) / (n(i + 1) - n(i)) B3B3 = B3(i) + (B3(i + 1) - B3(i)) * (nn - n(i)) / (n(i + 1) - n(i)) B4B4 = B4(i) + (B4(i + 1) - B4(i)) * (nn - n(i)) / (n(i + 1) - n(i)) End IfNext iBe = B0B0 + B1B1 * Pe + B2B2 * Pe ^ 2 + B3B3 * Pe ^ 3 + B4B4 * Pe ^ 4Qs = Pe * Be / (1.02 * 7 * ua)Picture1.PSet (ua, Qs), vbBlueIf Qs < Qmin ThenQmin = QsUj = uaEnd IfNext uaText1.Text = CInt(Uj * 100) / 100Text2.Text = CInt(Qmin * 100) / 100End Sub'..............次高挡百公里耗油量Private Sub Command2_Click()Picture1.ClsPicture1.DrawWidth = 1Dim n(1 To 8), B0(1 To 8), B1(1 To 8), B2(1 To 8), B3(1 To 8), B4(1 To 8)n(1) = 815: n(2) = 1207: n(3) = 1614: n(4) = 2012: n(5) = 2603: n(6) = 3006: n(7) = 3403: n(8) = 3804B0(1) = 1326.8: B0(2) = 1354.7: B0(3) = 1284.4: B0(4) = 1122.9: B0(5) = 1141#: B0(6) = 1051.2: B0(7) = 1233.9: B0(8) = 1129.7B1(1) = -416.46: B1(2) = -303.98: B1(3) = -189.75: B1(4) = -121.59: B1(5) = -98.893: B1(6) = -73.714: B1(7) = -84.478: B1(8) = -45.291B2(1) = 72.379: B2(2) = 36.657: B2(3) = 14.524: B2(4) = 7.0035: B2(5) = 4.4763: B2(6) = 2.8593: B2(7) = 2.9788: B2(8) = 0.71113B3(1) = -5.8629: B3(2) = -2.0553: B3(3) = -0.51184: B3(4) = -0.18517: B3(5) = -0.091077: B3(6) = -0.05138: B3(7) = -0.047449: B3(8) = -0.00075215B4(1) = 0.17768: B4(2) = 0.043072: B4(3) = 0.0068164: B4(4) = 0.0018555: B4(5) = 0.00068906: B4(6) = 0.00035032: B4(7) = 0.0002823: B4(8) = -0.000038568Picture1.Scale (-10, 50)-(150, -10)Picture1.Line (0, 0)-(120, 0): Picture1.Line (0, 0)-(0, 45)Picture1.CurrentX = 120: Picture1.CurrentY = -3: Picture1.Print "Ua(km/h)"Picture1.CurrentX = 120: Picture1.CurrentY = 1: Picture1.Print "→"Picture1.CurrentX = 5: Picture1.CurrentY = 45: Picture1.Print "Qs(L/100km)"Picture1.CurrentX = -2.5: Picture1.CurrentY = 46: Picture1.Print "↑"Picture1.CurrentX = -3: Picture1.CurrentY = -1: Picture1.Print "0"For i = 20 To 100 Step 20Picture1.Line (i, 0)-(i, 1)Picture1.CurrentX = i - 6: Picture1.CurrentY = -1: Picture1.Print iNext iFor i = 10 To 40 Step 10Picture1.Line (0, i)-(3, i)Picture1.CurrentX = -12: Picture1.CurrentY = i + 1: Picture1.Print iNext iPicture1.DrawWidth = 2m = 3880g = 3880 * 9.8f = 0.013CdA = 2.77ηt = 0.85i0 = 5.83r = 0.367Qmin = 100For ua = 25 To 100 Step 0.01Pe = (g * f * ua / 3600 + CdA * ua ^ 3 / 76140) / ηtnn = 0.793 * i0 * ua / (0.377 * r)For i = 1 To 7If nn >= n(i) And nn <= n(i + 1) ThenB0B0 = B0(i) + (B0(i + 1) - B0(i)) * (nn - n(i)) / (n(i + 1) - n(i)) B1B1 = B1(i) + (B1(i + 1) - B1(i)) * (nn - n(i)) / (n(i + 1) - n(i)) B2B2 = B2(i) + (B2(i + 1) - B2(i)) * (nn - n(i)) / (n(i + 1) - n(i)) B3B3 = B3(i) + (B3(i + 1) - B3(i)) * (nn - n(i)) / (n(i + 1) - n(i)) B4B4 = B4(i) + (B4(i + 1) - B4(i)) * (nn - n(i)) / (n(i + 1) - n(i)) End IfNext iBe = B0B0 + B1B1 * Pe + B2B2 * Pe ^ 2 + B3B3 * Pe ^ 3 + B4B4 * Pe ^ 4Qs = Pe * Be / (1.02 * 7 * ua)Picture1.PSet (ua, Qs), vbRed If Qs < Qmin ThenQmin = QsUj = uaEnd IfNext uaText1.Text = CInt(Uj * 100) / 100Text2.Text = CInt(Qmin * 100) / 100 End Sub2.数据图表：最高档等速百公里燃油消耗量曲线图：西华大学实验报告 第 页 次高档等速百公里燃油消耗量曲线图：。

门开度的大小，调节进入气缸的混合气的量来控制负荷的大小。

柴油机的负荷调节方式为“质调节”，在一定转速下通过调节向气缸内的喷射的燃油量来控制负荷的大小。

由于负荷调节方式以及燃烧方式不同，汽油机和柴油机的负荷特性也有所不同。

汽油机的指示热效率和柴油机指示热效率随负荷的变化规律相反。

汽油机燃油消耗率随负荷变化曲线比柴油机要陡，汽油机经济性指标比柴油机差，柴油机的燃油消耗率随负荷变化又缓慢又低，所以柴油机的经济性比汽油机的经济性强。

通过将发动机的各个参数绘制在一张图上形成发动机的万有特性曲线图，通过发动机万有特性曲线图可以看出在不同油耗下发动机运行的情况。

绘制万有特性曲线的方法有负荷特性法和速度特性法。

在绘制时，首先绘制不同转速下的负荷特性曲线组或者不同负荷下的速度特性曲线组，然后通过坐标转换，将负荷特性曲线组或者速度特性曲线组转换成等油耗的万有特性。

在等油耗万有曲线图上等油耗线越向外，燃油消耗率越高，经济性越差。

在水平方向上等间隔的油耗线稀疏，说明转速的变化对经济性影响较小，反之影响较大。

同理垂直方向上转速的等油耗线的疏密程度表明了发动机的经济性对负荷变化的适应性。

如果垂直方向上曲线分布密集，表明经济性对负荷变化较为敏感。

Visual Basic是一种由微软公司开发的包含协助开发环境的事件驱动编程语言。

它源自于BASIC编程语言。

VB拥有图形用户界面（GUI）和快速应用程序开发（RAD）系统，可以轻易的使用DAO、RDO、ADO连接数据库，或者轻松的创建ActiveX控件。

程序员可以轻松使用VB提供的组件快速建立一个应用序。

Visual Basic是一种可视化的编程语言，利用这种可视化技术进行编程，能使编程工作变得轻松快捷，摆脱了面向过程语言的许多细节，而是将主要精力集中在解决实际问题和设计友好界面上。

因此Visual Basic在国内外各个领域的应用非常广泛，许多计算机专业和非计算机专业的人员常用它来编制开发应用程序和软件。

'添加个picture1和command1Option ExplicitDim lngCenter As LongDim lngMax As LongDim lngPad&Dim PCurrent As POINT, PLast As POINTPrivate Type POINTx As Longy As LongEnd TypePrivate Sub Form_Load()lngCenter = (Picture1.Top + Picture1.Height) / 2lngMax = Picture1.HeightPLast.x = 0PLast.y = lngCenterDim i&For i = 0 To Picture1.Width Step 100Picture1.Line (i, 0)-(i, Picture1.Height), &HFFC0C0NextFor i = 0 To Picture1.Height Step 100Picture1.Line (0, i)-(Picture1.Width, i), &HFFC0C0NextPicture1.DrawWidth = 1.5Picture1.Line (0, lngCenter)-(Picture1.Width, lngCenter), vbBlue Picture1.DrawWidth = 1End SubPrivate Sub Timer1_Timer()PCurrent.x = PCurrent.x + 50RandomizePCurrent.y = Rnd * lngMaxPicture1.Line (PCurrent.x, PCurrent.y)-(PLast.x, PLast.y), vbRed PLast.x = PCurrent.xPLast.y = PCurrent.yEnd SubPrivate Sub Command1_Click()Timer1.Enabled = Not Timer1.EnabledEnd Sub效果图：如果需要带有点规律性可以将获得y的坐标稍加处理下：Private Function getRndY() As IntegerDim lngTmp%If intRnd = 0 ThenRandomizeintRnd = Rnd * 3 + 1End IfRandomizelngTmp = Rnd * lngCenterIf PLast.y > lngCenter ThengetRndY = lngCenter + lngTmpElsegetRndY = lngTmpEnd IfintCurRnd = intCurRnd + 1If intCurRnd > intRnd ThenRandomizeintRnd = Rnd * 3 + 1&nb ......Public Sub Draw_Sin _( _pic1 As PictureBox, _sngXFrom As Single, _sngXTo As Single, _)Dim x1 As Single, y1 As SingleDim x2 As Single, y2 As Singlex1 = sngXFromy1 = Sin(x1)For x2 = (sngXFrom + sngStep) To sngXTo Step 0.1y2 = Sin(x2)pic1.Line (ScaleX_MathToScreen(x1),ScaleY_MathToScreen(y1)) _-(ScaleX_MathToScreen(x2),ScaleY_MathToScreen(y2))x1 = x2y1 = y2NextEnd SubPrivate Function ScaleX_MathToScreen(sngX As Single) ScaleX_MathToScreen = 500+ sngX * 500End FunctionPrivate Function ScaleY_MathToScreen(sngY As Single)ScaleY_MathToScreen = 500- sngY * 500End FunctionOption ExplicitPrivate Sub Form_click()ClsDim i, j As SingleMe.Scale (-1, 10)-(25, -1) '定义坐标系，原点靠近左下角Line (-1, 0)-(25, 0) '画x轴Line (0, -1)-(0, 10) '画Y轴For i = -1 To 25 Step 1 '画X轴刻度If i <> 0 ThenLine (i, 0)-(i, 0.2)CurrentX = i - 0.3: CurrentY = -0.2Print iEnd IfNextFor j = -1 To 10 '画Y轴刻度If j <> 0 ThenLine (0, j)-(0.3, j)CurrentX = -0.7: CurrentY = j + 0.1Print jEnd IfNextCurrentX = -0.4: CurrentY = -0.2Print "0" '画原点CurrentX = 0.5: CurrentY = 9.5Print "Y"CurrentX = 24: CurrentY = 0.5Print "X"RandomizeCurrentX = 1: CurrentY = Format(Rnd * 10, "0.00")For i = 2 To 24Line -(i, Format(Rnd * 10, "0.00")) '这里是随机生成的数据！NextEnd Sub在Form1中加Picture1控件Option ExplicitPrivate Sub Form1.Picture1_click()ClsDim i, j As SingleMe.Scale (-1, 10)-(25, -1) '定义坐标系，原点靠近左下角with Form1.Picture1Line (-1, 0)-(25, 0) '画x轴Line (0, -1)-(0, 10) '画Y轴For i = -1 To 25 Step 1 '画X轴刻度If i <> 0 ThenLine (i, 0)-(i, 0.2)CurrentX = i - 0.3: CurrentY = -0.2Print iEnd IfNextFor j = -1 To 10 '画Y轴刻度If j <> 0 ThenLine (0, j)-(0.3, j)CurrentX = -0.7: CurrentY = j + 0.1Print jEnd IfNextCurrentX = -0.4: CurrentY = -0.2Print "0" '画原点CurrentX = 0.5: CurrentY = 9.5Print "Y"CurrentX = 24: CurrentY = 0.5Print "X"RandomizeCurrentX = 1: CurrentY = Format(Rnd * 10, "0.00")For i = 2 To 24Line -(i, Format(Rnd * 10, "0.00")) '这里是随机生成的数据！Nextend withEnd Sub还可以更完善.。

基于VB汽车发动机故障诊断系统的设计序言自20世纪50 年代汽车技术与电子技术开始结合以来，电子技术在汽车上的应用范围越来越广，特别是70年代后，电子技术领域的集成电路、大规模集成电路和超大规模集成电路的发展，为汽车提供了处理快速、功能强大、性能可靠、成本低廉的汽车电子控制系统。

汽车电子控制系统极大地提高了汽车的动力性、经济性、安全性、舒适性，同时能够很好地解决汽车尾气排放问题和节能问题。

信息技术革命正在推动汽车技术翻开新的一页。

人类将迎来汽车的数字化、汽车的网络化、汽车的智能化，21世纪的汽车将成为一种智能的多媒体。

由于电子产品在汽车上的广泛应用，汽车综合性能在不断提升的同时，汽车的疑难杂症也逐渐增多，这对汽车维修人员提出了更高的要求。

在汽车的这些故障中，发动机所产生的故障占汽车总故障的19.8%以上，单位里程的配件消耗（在全车中约占24.0%）、保修工时消耗（在全车中约占24.0%）都很多。

而发动机是汽车其它机械运动的主要动力来源，其结构越来越复杂、工作条件也越来越苛刻，一旦出现故障将会直接导致汽车无法正常行驶。

综上所述，对汽车发动机展开故障诊断技术和系统的设计有着非常重要的现实意义。

国外汽车制造技术领先我们几十年，早就出现了类似的故障诊断专家系统或汽车资料数据库系统。

我国从20世纪60年代开始研究汽车检测技术，当时由交通部门主持研制了一些简单的诊断设备。

70年代末，我国下达了第一个关于汽车维修方面的国家级课题——“汽车不解体检测技术”。

从此，汽车检测与诊断技术在我国掀开了一个新篇章。

进入 80年代后，随着国民经济的发展，在交通部门的统筹规划下，汽车检测诊断技术再一次得到了迅速发展。

本课题结合帕萨特发动机的维修手册，构建基于Microsoft Visual Basic6.0系统，亦即是以VB6.0为开发平台，对汽车帕萨特发动机性能中的机械故障、电子故障进行诊断。

其中的诊断内容包括常见故障查询、1552代码查询、数据流分析、发动机系统简介、维修工艺简介、案例查询、案例添加等子系统。