从 BLF 文件中解码 CAN 数据
此示例说明如何在 MATLAB® 中从 BLF 文件中导入和解码 CAN 数据进行分析。此示例中使用的 BLF 文件是使用 Vector 的 CANoe™ 基于 CAN - General System Configuration (CAN) 采样生成的。此示例还使用 Vector 采样配置提供的 CAN 数据库文件 PowerTrain_BLF.dbc
。
打开 DBC 文件
使用 canDatabase
函数打开描述源 CAN 网络的数据库文件。
canDB = canDatabase("PowerTrain_BLF.dbc")
canDB = Database with properties: Name: 'PowerTrain_BLF' Path: '/tmp/Bdoc24a_2511836_3070643/tp8879c7f7/vnt-ex06202590/PowerTrain_BLF.dbc' UTF8_File: '/tmp/Bdoc24a_2511836_3070643/tp8879c7f7/vnt-ex06202590/PowerTrain_BLF.dbc' Nodes: {2x1 cell} NodeInfo: [2x1 struct] Messages: {12x1 cell} MessageInfo: [12x1 struct] Attributes: {11x1 cell} AttributeInfo: [11x1 struct] UserData: []
调查 BLF 文件
检索和查看有关 BLF 文件的信息。函数 blfinfo
解析有关 Vector 二进制记录格式 BLF 文件的格式和内容的一般信息,并将信息以结构体形式返回。
binf = blfinfo("Logging_BLF.blf")
binf = struct with fields:
Name: "Logging_BLF.blf"
Path: "/tmp/Bdoc24a_2511836_3070643/tp8879c7f7/vnt-ex06202590/Logging_BLF.blf"
Application: "CANoe"
ApplicationVersion: "11.0.55"
Objects: 43344
StartTime: 01-Jul-2020 14:47:34.427
EndTime: 01-Jul-2020 14:48:33.487
ChannelList: [2x3 table]
binf.ChannelList
ans=2×3 table
ChannelID Protocol Objects
_________ ________ _______
1 "CAN" 8801
2 "CAN" 7575
从 BLF 文件中读取数据
从动力总成系统总线记录感兴趣的数据,并存储在 BLF 文件的通道 2 中。使用 blfread
函数读取 CAN 数据。您还可以向函数调用提供 DBC 文件,该函数调用将启用报文名称查找和信号值解码。
blfData = blfread("Logging_BLF.blf", 2, "Database", canDB)
blfData=7575×8 timetable
Time ID Extended Name Data Length Signals Error Remote
__________ ____ ________ __________________ ______________________________ ______ ____________ _____ ______
2.2601 sec 103 false {'Ignition_Info' } {[ 1 0]} 2 {1x1 struct} false false
2.2801 sec 103 false {'Ignition_Info' } {[ 1 0]} 2 {1x1 struct} false false
2.3002 sec 100 false {'EngineData' } {[ 238 2 25 1 0 0 238 2]} 8 {1x1 struct} false false
2.3005 sec 102 false {'EngineDataIEEE'} {[ 0 128 59 68 0 0 0 0]} 8 {1x1 struct} false false
2.3006 sec 103 false {'Ignition_Info' } {[ 1 0]} 2 {1x1 struct} false false
2.3008 sec 201 false {'ABSdata' } {[ 0 0 0 0 172 38]} 6 {1x1 struct} false false
2.3009 sec 1020 false {'GearBoxInfo' } {[ 1]} 1 {1x1 struct} false false
2.3201 sec 103 false {'Ignition_Info' } {[ 1 0]} 2 {1x1 struct} false false
2.3401 sec 103 false {'Ignition_Info' } {[ 1 0]} 2 {1x1 struct} false false
2.3502 sec 100 false {'EngineData' } {[ 4 0 25 2 119 1 238 2]} 8 {1x1 struct} false false
2.3505 sec 102 false {'EngineDataIEEE'} {[53 127 119 64 0 128 187 67]} 8 {1x1 struct} false false
2.3507 sec 201 false {'ABSdata' } {[ 0 0 0 0 35 40]} 6 {1x1 struct} false false
2.3508 sec 1020 false {'GearBoxInfo' } {[ 1]} 1 {1x1 struct} false false
2.3601 sec 103 false {'Ignition_Info' } {[ 1 0]} 2 {1x1 struct} false false
2.3801 sec 103 false {'Ignition_Info' } {[ 1 0]} 2 {1x1 struct} false false
2.4002 sec 100 false {'EngineData' } {[ 10 0 25 3 119 1 238 2]} 8 {1x1 struct} false false
⋮
查看来自“EngineData”报文的信号。
blfData.Signals{3}
ans = struct with fields:
PetrolLevel: 1
EngPower: 7.5000
EngForce: 0
IdleRunning: 0
EngTemp: 0
EngSpeed: 750
重新打包并可视化感兴趣的信号值
使用 canSignalTimetable
函数将来自总线上每个唯一报文的信号数据重新打包为一个信号时间表。此示例根据 CAN 报文时间表,为三个感兴趣的报文“ABSdata”、“EngineData”和“GearBoxInfo”创建三个单独的信号时间表。
signalTimetable1 = canSignalTimetable(blfData, "ABSdata")
signalTimetable1=1136×4 timetable
Time AccelerationForce Diagnostics GearLock CarSpeed
__________ _________________ ___________ ________ ________
2.3008 sec -100 0 0 0
2.3507 sec 275 0 0 0
2.4008 sec 275 0 0 0
2.4507 sec 275 0 0 0
2.5008 sec 275 0 0 0
2.5507 sec 275 0 0 0
2.6008 sec 275 0 0 0
2.6507 sec 275 0 0 0
2.7008 sec 350 0 0 0
2.7507 sec 425 0 0 0.5
2.8008 sec 425 0 0 0.5
2.8507 sec 500 0 0 0.5
2.9008 sec 575 0 0 0.5
2.9507 sec 575 0 0 0.5
3.0008 sec 650 0 0 0.5
3.0507 sec 725 0 0 0.5
⋮
signalTimetable2 = canSignalTimetable(blfData, "EngineData")
signalTimetable2=1136×6 timetable
Time PetrolLevel EngPower EngForce IdleRunning EngTemp EngSpeed
__________ ___________ ________ ________ ___________ _______ ________
2.3002 sec 1 7.5 0 0 0 750
2.3502 sec 2 7.5 375 0 0 4
2.4002 sec 3 7.5 375 0 0 10
2.4502 sec 4 7.5 375 0 0 17
2.5002 sec 5 7.5 375 0 0 23
2.5502 sec 6 7.5 375 0 0 30
2.6002 sec 7 7.5 375 0 0 36
2.6502 sec 8 7.5 375 0 0 43
2.7002 sec 9 9 450 0 0 50
2.7502 sec 10 10.5 525 0 0 59
2.8002 sec 10 10.5 525 0 0 69
2.8502 sec 11 12 600 0 0 80
2.9002 sec 11 13.5 675 0 0 92
2.9502 sec 12 13.5 675 0 0 106
3.0002 sec 13 15 750 0 0 121
3.0502 sec 13 16.5 825 0 0 136
⋮
signalTimetable3 = canSignalTimetable(blfData, "GearBoxInfo")
signalTimetable3=1136×3 timetable
Time EcoMode ShiftRequest Gear
__________ _______ ____________ ____
2.3009 sec 0 0 1
2.3508 sec 0 0 1
2.4009 sec 0 0 1
2.4508 sec 0 0 1
2.5009 sec 0 0 1
2.5508 sec 0 0 1
2.6009 sec 0 0 1
2.6508 sec 0 0 1
2.7009 sec 0 0 1
2.7508 sec 0 0 1
2.8009 sec 0 0 1
2.8508 sec 0 0 1
2.9009 sec 0 0 1
2.9508 sec 0 0 1
3.0009 sec 0 0 1
3.0508 sec 0 0 1
⋮
为了可视化感兴趣的信号,可以绘制信号时间表中的列随时间变化的图,以便进一步分析。
subplot(3, 1, 1) plot(signalTimetable1.Time, signalTimetable1.CarSpeed, "r") title("{\itCarSpeed} Signal from {\itABSdata} Message", "FontWeight", "bold") xlabel("Timestamp") ylabel("Car Speed") subplot(3, 1, 2) plot(signalTimetable2.Time, signalTimetable2.EngSpeed, "b") title("{\itEngSpeed} Signal from {\itEngData} Message", "FontWeight", "bold") xlabel("Timestamp") ylabel("Engine Speed") subplot(3, 1, 3) plot(signalTimetable3.Time, signalTimetable3.Gear, "y") title("{\itGear} Signal from {\itGearBoxInfo} Message", "FontWeight", "bold") xlabel("Timestamp") ylabel("Gear")