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 <iostream>
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;

		
}

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