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使用 Stateflow 图的空燃比控制系统

为使用 Simulink® 和 Stateflow® 设计的空燃比控制系统生成代码。

图 1、2 和 3 显示了 sldemo_fuelsys 模型(包含被控对象和控制器的闭环系统)的相关部分。被控对象在设计周期早期阶段的仿真过程中验证控制器。在此示例中,您将为相关控制器子系统 fuel_rate_control 生成代码。图 1 显示顶层仿真模型。

打开并配置 sldemo_fuelsys 模型。然后,编译模型以查看信号数据类型。

model = 'sldemo_fuelsys';
open_system(model)
coder.example.configure(model,'ERT','float');
set_param(model,'ShowPortDataTypes','on');
set_param(model,'SampleTimeColors','on');
sldemo_fuelsys([],[],[],'compile');
sldemo_fuelsys([],[],[],'term');

图 1:被控对象和控制器的顶层模型

空燃比控制系统由 Simulink 和 Stateflow 组成。控制系统是指您为其生成代码的模型部分。

open_system('sldemo_fuelsys/fuel_rate_control');

图 2:空燃比控制器子系统

控制逻辑是指定不同操作模式的 Stateflow 图。

open_system('sldemo_fuelsys/fuel_rate_control/control_logic');

图 3:空燃比控制器逻辑

关闭这些窗口。

close_system('sldemo_fuelsys/fuel_rate_control/airflow_calc');
close_system('sldemo_fuelsys/fuel_rate_control/fuel_calc');
close_system('sldemo_fuelsys/fuel_rate_control/control_logic');
hDemo.rt=sfroot;hDemo.m=hDemo.rt.find('-isa','Simulink.BlockDiagram');
hDemo.c=hDemo.m.find('-isa','Stateflow.Chart','-and','Name','control_logic');
hDemo.c.visible=false;
close_system('sldemo_fuelsys/fuel_rate_control');

使用 Embedded Coder 配置并构建模型

要为模型配置和编译生产 ANSI® C/C++ 代码,请将模型配置参数系统目标文件设置为 ert.tlc(嵌入式实时 (ERT))。您可以通过编程方式设置系统目标文件参数。

coder.example.configure('sldemo_fuelsys','ERT');

生成并检查代码。您可以使用上一步下一步按钮,以交互方式导航到相关的代码段。从图上下文菜单(右键点击 Stateflow 模块)中,选择 C/C++ 代码 > 导航至 C/C++ 代码。以编程方式使用 rtwtrace 实用工具。

slbuild('sldemo_fuelsys/fuel_rate_control');
rtwtrace('sldemo_fuelsys/fuel_rate_control/control_logic')
### Starting build procedure for: fuel_rate_control
### Successful completion of build procedure for: fuel_rate_control

Build Summary

Top model targets built:

Model              Action                        Rebuild Reason                                    
===================================================================================================
fuel_rate_control  Code generated and compiled.  Code generation information file does not exist.  

1 of 1 models built (0 models already up to date)
Build duration: 0h 0m 24.513s

查看生成的代码中的空燃比控制逻辑。

coder.example.extractLines('fuel_rate_control_ert_rtw/fuel_rate_control.c',...
    '/* Function for Chart:','case IN_Warmup:',1,0);
/* Function for Chart: '<S1>/control_logic' */
static void Fueling_Mode(const int32_T *sfEvent)
{
  switch (rtDWork.bitsForTID0.is_Fueling_Mode) {
   case IN_Fuel_Disabled:
    rtDWork.fuel_mode = DISABLED;
    switch (rtDWork.bitsForTID0.is_Fuel_Disabled) {
     case IN_Overspeed:
      /* Inport: '<Root>/sensors' */
      if ((rtDWork.bitsForTID0.is_Speed == IN_normal) && (rtU.sensors.speed <
           603.0F)) {
        if (rtDWork.bitsForTID0.is_Fail != IN_Multi) {
          rtDWork.bitsForTID0.is_Fuel_Disabled = IN_NO_ACTIVE_CHILD;
          rtDWork.bitsForTID0.is_Fueling_Mode = IN_Running;

          /* The fuel is actively controlled while in this state. */
          switch (rtDWork.bitsForTID0.was_Running) {
           case IN_Low_Emissions:
            rtDWork.bitsForTID0.is_Running = IN_Low_Emissions;
            rtDWork.bitsForTID0.was_Running = IN_Low_Emissions;
            rtDWork.fuel_mode = LOW;
            switch (rtDWork.bitsForTID0.was_Low_Emissions) {
             case IN_Normal:
              rtDWork.bitsForTID0.is_Low_Emissions = IN_Normal;
              rtDWork.bitsForTID0.was_Low_Emissions = IN_Normal;

              /* All sensors are in correct operating modes, so effective closed-loop mixture control can be used. */
              break;

关闭模型和代码生成报告。

clear hDemo;
close_system('sldemo_fuelsys',0);