实时控制软件第二周 停车场门禁控制系统的状态机的设计

控制系统的状态机设计

控制系统的状态

• 等待车辆（waiting）
• 起落杆上升（opening）
• 等待车辆通过（passing）
• 起落杆下降（closing）

外部事件 输入信号

• 入闸传感器：汽车进入 signal_in
• 出闸传感器：汽车离开 signal_out
• 起落杆上传感器，起落杆升到顶部 signal_up
• 起落杆下传感器，起落杆降到底部 signal_down

动作

• 起落杆的生降
• 红绿灯的变换

状态跃迁及触发信号

• waiting 》opening 入闸传感器信号
• opening 》passing 起落杆上传感器 灯变位绿
• passing 》closing 出闸传感器
• closing 》 waiting 起落杆下传感器 灯变位红

状态机的C++实现

include

using namespace std;

enum state { waiting, opening, passing, closing };
enum light { red,green};
enum signal { signal_in, signal_out, signal_up, signal_down};

void state_change(enum signal signal);

int main()
{
char c=0x00;
while (1)
{
c = getchar();
switch (c)
{
case 'i':state_change(signal_in);
break;
case 'u':state_change(signal_up);
break;
case 'o':state_change(signal_out);
break;
case 'd':state_change(signal_down);
break;
default:
break;
}

}

}

void state_change(enum signal signal)
{
static enum state currentState = waiting;
static enum light l = red;
static string str_state="";
static string str_light="";
switch (currentState)
{
case waiting:
switch (signal)
{
case signal_in:
currentState = opening;
break;
default:
break;
}
case opening:
switch (signal)
{
case signal_up:
currentState = passing;
l = green;
default:
break;
}
case passing:
switch (signal)
{
case signal_out:
currentState = closing;

default:
break;
}
case closing:
switch (signal)
{
case signal_down:
currentState = waiting;
l = red;
default:
break;
}
default:
break;
}

//输出状态
switch (currentState)
{
case waiting:
str_state = "waiting";
break;
case opening:
str_state = "opening";
break;
case passing:
str_state = "passing";
break;
case closing:
str_state = "closing";
break;
default:
break;
}
switch (l)
{
case red:
str_light = "red";
break;
case green:
str_light = "green";
break;
default:
break;
}

cout << "Current state:"<< str_state.c_str() << endl;
cout << "Light color:" <<str_light.c_str() << endl;

}

Written with StackEdit.