Project 2 - Implement the Code for controlling the retraction and extension of Airplane’s landing gear

Aim: Code for controlling the retraction and extension of Airplane’s landing gear.

Description of the Hardware:

Actually an airplane has 3 gears for landing :
• Nose Gear
• Left Gear
• Right Gear
There is a hydraulic pump which is exerting pressure to the
gears to bring it down or pull it up and that pump is
electrically driven.

Limit switches:

Every leg of the gear has one limit switch.Nose gear has
one extra Squat Switch to determine whether the airplane
is in ground or not.

Main Code:

#include
#include"FSH.h"
static void (*state_table[])(void)= {Gear_Down, Checking_Before_Takeoff, Raising_Gear,
		Gear_Up,Checking_Before_Landing, Lowering_Gear};
int main()
{
	Init_State_Machine();
	while(1)
{
		state_table[current_state]();
}
}


void Init_State_Machine()
{

	current_state = GR_DWN;
	printf("\n State machine is initialized & Program is in Gear_Down State & Light Status :%s\n",
			State_Machine[current_state].light_status);
}

void Gear_Down(void)
{
	current_state= GR_DWN;

	printf("\n Enter the Pilot's Lever Position and Squat Switch Status:");
	fflush(stdout);
	scanf("%d %d",&pilot_lever,&squat_switch);
	if(pilot_lever == Rising && squat_switch == open)
	{
		current_state = CHK_BFR_TKFF;
		printf("\n Current State: %s\n",State_Machine[current_state].current_state_indication);
		printf("Light Status: %s\n",State_Machine[current_state].light_status);
	}
	else
	{
		Gear_Down();
	}
}

void Checking_Before_Takeoff()
{
current_state = CHK_BFR_TKFF;

printf("\n Enter the Pilot's Lever Position,Squat Switch Status and Hydraulic Mechanism Status:");
fflush(stdout);
scanf("%d %d %d",&pilot_lever, &squat_switch, &hydraulic_mechanism);
printf("\n Wait for 2 secs\n");
if(pilot_lever == Falling || squat_switch == close)
{
	Gear_Down();
}
else if(pilot_lever == UP && squat_switch == open && hydraulic_mechanism == Working)
{
	current_state = RSING_GR;
	printf("\n Current State: %s\n", State_Machine[current_state].current_state_indication);
	printf("Light Status: %s\n", State_Machine[current_state].light_status);
	printf("Direction Valve Status: %s \n\n", State_Machine[current_state].direction_valve_status);
}
else if(pilot_lever == UP && squat_switch == open && hydraulic_mechanism == Malfunctioning)
{
	current_state = RSING_GR;
	printf("\n Current State: %s\n", State_Machine[current_state].current_state_indication);
	printf("Light Status: %s\n", State_Machine[current_state].light_status);
	printf("Direction Valve Status: %s\n", State_Machine[current_state].direction_valve_status);
	printf("Gas Pressurized Spring System Status: %s\n",State_Machine[current_state].gas_pressurized_spring_status);
}
}

void Raising_Gear()
{
	current_state = RSING_GR;

	printf("\n Enter the Limit Switch Status,Pilots Leaver Status:");
	fflush(stdout);
	scanf("%d %d",&limit_switch,&pilot_lever);
	printf("\n Wait for 1 sec \n");
	if(pilot_lever == Falling && limit_switch == open)
	{
		current_state = CHK_BFR_LND;
		printf("\Current State: %s\n", State_Machine[current_state].current_state_indication);
		printf("Light Status: %s \n",State_Machine[current_state].light_status);
		printf("Hydraulic Control for Landing Gear Status: %s\n", State_Machine[current_state].hydraulic_pump_control_status);
	}
	else if(limit_switch == close && pilot_lever == UP)
	{
		current_state = GR_UP;
		printf("\n Current State: %s\n", State_Machine[current_state].current_state_indication);
		printf("Light status: %s\n",State_Machine[current_state].light_status);
		printf("Hydraulic Control for Landing Gear Status: %s\n",State_Machine[current_state].hydraulic_pump_control_status);
	}
	else
	{
		Raising_Gear();
	}
}


void Gear_Up()
{
	current_state = GR_UP;

	printf("\n Enter the Pilot's Lever Position");
	fflush(stdout);
	scanf("%d",&pilot_lever);
	if(pilot_lever == Falling)
	{
		current_state = CHK_BFR_LND;
printf("\n Current State: %s\n",State_Machine[current_state].current_state_indication);
printf("Light Status: %s\n",State_Machine[current_state].light_status);
printf("Hydraulic Control for Landing Gear Status: %s\n", State_Machine[current_state].hydraulic_pump_control_status);
	}
	else
	{
		Gear_Up();
	}
}


void Checking_Before_Landing()
{
	current_state = CHK_BFR_LND;

printf("\n Enter the Pilot's Lever Position and Status of Hydraulic Mechanism:");
fflush(stdout);
scanf("%d%d",&pilot_lever, &hydraulic_mechanism);
if(pilot_lever == DOWN && hydraulic_mechanism == Working)
{
	current_state = LWRNG_GR;
	printf("\n Current State: %s\n",State_Machine[current_state].current_state_indication);
	printf("Light Status: %s\n",State_Machine[current_state].light_status);
	printf("Direction Valve Status: %s\n",State_Machine[current_state].direction_valve_status);
}
else if(pilot_lever == DOWN && hydraulic_mechanism == Malfunctioning)
{
	current_state = LWRNG_GR;
	printf("\n Current State: %s\n",State_Machine[current_state].current_state_indication);
	printf("Light Status: %s\n",State_Machine[current_state].light_status);
	printf("Direction Valve Status: %s\n",State_Machine[current_state].direction_valve_status);


}
if(pilot_lever== (UP || Rising || Falling))
{
	Checking_Before_Landing();
}
}

void Lowering_Gear()
{
	current_state = LWRNG_GR;

	printf("\n Enter the Limit Switch Status, Pilots Leaver Status::");
	fflush(stdout);
	scanf("%d%d",&limit_switch,&pilot_lever);
	if(limit_switch == close && pilot_lever == Rising)
	{
		current_state = CHK_BFR_TKFF;
		printf("\n Current State: %s\n", State_Machine[current_state].current_state_indication);
		printf("Light Status:%s\n", State_Machine[current_state].light_status);
	}
if(limit_switch == open && pilot_lever == DOWN)
{
	current_state = GR_DWN;
	printf("\n Current State: %s\n",State_Machine[current_state].current_state_indication);
	printf("Light Status:%s\n",State_Machine[current_state].light_status);
	printf("Hydraulic Control for Landing Gear Status:%s\n",State_Machine[current_state].hydraulic_pump_control_status);
}

else
{
	Lowering_Gear();
}
}

+

Header File:

#ifndef FSH_H_
#define FSH_H_

#include
void Int_State_Machine();
void Gear_Down();
void Checking_Before_Takeoff();
void Raising_Gear();
void Gear_Up();
void Checking_Before_Landing();
void Lowering_Gear();
typedef enum State
{
	GR_DWN,
	CHK_BFR_TKFF,
	RSING_GR,
	GR_UP,
	CHK_BFR_LND,
	LWRNG_GR
}State_Type;
typedef enum Switch
{
	open,
	close
}Switch_Status;
typedef enum Pilot_lever
{
	Rising,
	Falling,
	UP,
	DOWN
}Pilot_Lever_Status;
typedef enum Hydraulic_Mechanism
{
	Working,
	Malfunctioning
}Hydraulic_Mechanism_status;

static volatile Switch_Status squat_switch;
static volatile Switch_Status limit_switch;
static volatile Pilot_Lever_Status pilot_lever;
static volatile Hydraulic_Mechanism_status hydraulic_mechanism;

State_Type current_state;
typedef struct
{
	char* current_state_indication;
	char* light_status;
	char* direction_valve_status;
	char* hydraulic_pump_control_status;
	char* gas_pressurized_spring_status[2];
}State_Table;
static State_Table State_Machine[6]={
		{"Gear Down", "Green", "Down", "Enabled",{0,0}},
		{"Checking Before Take Off","Green", "Down", "Enabled",{0,0}},
		{"Raising Gear","Red","Up","Enabled",{"Disabled","Enabled"}},
		{"Gear Up","Off","Null","Disabled",{0,0}},
		{"Checking Before Landing","Red","Down","Enabled",{0,0}},
		{"Lowering Gear","Green","Down","Enabled",{"Disabled,Enabled"}}
};

Output :