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

Overview of the Project: (5 to 6 lines)

In this project, controlling the retraction and extension of Airplane’s landing gear can be implemented using Finite State Machine (FSM). FSM is the most efficient algorithm which is mathematical model of computation.

Goals ( 2 to 3 points)

• Controlling the direction of Valve.
• Controlling the retraction and extension of Airplane’s landing gear.

Key Highlights of the Project: (4 to 5 points)

A direction valve is controlled by the software to allow the hydraulic pressure to either raise or lower the landing gear.

Deliverables of this project: (4 to 5 points)

Implementing the control for the retraction and extension of Airplane’s landing gear using the Finite state machine with the knowledge of various states of switch and gear.

Expected Outcomes: (4 to 5 points)

The student will be getting the Knowledge of Finite State Machine algorithm which is used to achieve the control over the retraction and extension of Airplane’s landing gear using the switch and gear states of Airplane.

AIM:

GR_DWN(0):

State Machine is initialized & Program is in Gear_Down State & Light_Status : Green

Enter the Pilot's Lever Position and Squat Switch Status:0 0

Current State:Checking Before Take Off
Light Status:Green

CHK_BFR_TKFF(1):

Enter the Pilot's Lever Position,Squat Switch Status and Hydraulic Mechanism Status:2 0 0

Wait for 2 secs

Current State: Raising Gear
Light Status:Red
Direction Value Status:Up

RSING_GR(2):

Enter the Limit Switch Status, Pilot's Lever Position :1 2

Wait for 1 sec

Current State: Gear Up
Light Status:Off
Hydraulic Control for Landing Gear Status:Disabled

GEAR_UP(3):

Enter the Pilot's Lever Position:1

Current State:Checking Before Landing
Light Status:Red
Hydraulic Control for Landing Gear Status:Enabled

CHK_BFR_LANDING(4):

Enter the Pilot's Lever Position and Status of Hydraulic Mechanism:3 1

Current State : Lowering Gear
Light Status:Green
Direction Valve Status:Down
Gas Pressurized Spring System Status:Enabled

LWRING_GR(5):

Enter the Limit_Switch Status,Pilot_Lever Status ::1 0

Current State: Checking Before Take Off
Light Status:Green

C Code:

#include <stdio.h>

#include<states.h>

void Initiate_State_Machine();
void GearDown();
void CheckingBeforeTakeOFF();
void RaisingGear();
void GearUp();
void CheckBeforeLanding();
void LoweringGear();
static void(*statetable[])
(void)={GearDown, CheckingBeforeTakeOFF, RaisingGear, GearUp, CheckBeforeLanding, LoweringGear};
typedef enum State
{
GEAR_DOWN,
CHECKING_BEFORE_TAKEOFF,
RAISING_GEAR,
GEAR_UP,
CHECK_BEFORE_LANDING,
LOWERING_GEAR,
}State_Type;
typedef enum Switch
{
on,
off,
}Switch_status;
typedef enum pilot_lever
{
Raising,
falling
}pilot_lever;
typedef enum hydraulic_mechanism
{
working,
not_working
}hydraulic_mechanism;

static volatile Switch_status squat_switch;
static volatile Switch_status limit_switch;
static volatile pilot_lever pl;
static volatile hydraulic_mechanism hm;

State_Type current_state;

typedef struct
{
char* current_state_indication;
char* light;
char* direction_valve_status;
char* landing_gear_hydraulic_control;
char* Gas_Pressurized_Spring_system_status[2];

}State_Table;

static State_Table State_Machine[6]={{"GearDown","Green","Down","Enabled",{NULL,NULL}},
{"CheckingBeforeTakeOFF","Green","Down","Enabled",{NULL,NULL}},
{"RaisingGear","Red","Up","Enabled",{NULL,NULL}},
{"GearUp","Off","NULL","Disabled",{NULL,NULL}},
{"CheckBeforeLanding","Red","Down","Enabled",{NULL,NULL}},
{"LoweringGear","Green","Down","Enabled",{"Disabled","Enabled"}}
};
int main()
{
Initiate_State_Machine();
while(1)
{
statetable[current_state]();
}
}
void GearDown(void)
{
current_state=GEAR_DOWN;
printf("Enter the status of pilot's lever and squat switch");
fflush(stdout);
scanf("%d %d",&pl,&squat_switch);
if(pl==Raising && squat_switch==on)
{
current_state=CHECKING_BEFORE_TAKEOFF;
printf("current state:%s\n",State_Machine[current_state].current_state_indication);
printf("Light is :%s\n", State_Machine[current_state].light);
}
else
{
GearDown();
}
}

void CheckingBeforeTakeOFF(void)
{
current_state=CHECKING_BEFORE_TAKEOFF;
printf("Enter the status of pilot's lever and squat switch and hydraulic mechanism:");
fflush(stdout);
scanf("%d %d",&pl,&squat_switch,&hm);
if(pl==falling&&squat_switch==off)
{
GearDown();
}
else if(pl==Raising && squat_switch==on && hm==working)
{
current_state=RAISING_GEAR;
printf("Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("Light is:%s\n",State_Machine[current_state].light);
printf("Status of Direction valve:%s\n",State_Machine[current_state].direction_valve_status);
}
else if(pl==Raising && squat_switch==on && hm==not_working)
{
current_state=RAISING_GEAR;
printf("Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("Light is:%s\n",State_Machine[current_state].light);
printf("Status of Direction valve:%s\n",State_Machine[current_state].direction_valve_status);
printf("Status of gas pressurised Spring System:%s\n",State_Machine[current_state].Gas_Pressurized_Spring_system_status);
}
}

void RaisingGear(void)
{
current_state=RAISING_GEAR;
printf("Enter the status of pilot's lever and limit switch:");
fflush(stdout);
scanf("%d %d",&pl,&limit_switch);
if(pl==falling && limit_switch==on)
{
current_state=CHECK_BEFORE_LANDING;
printf("Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("Light is:%s\n",State_Machine[current_state].light);
printf("Landing Gear Hydraulic Control:%s\n",State_Machine[current_state].landing_gear_hydraulic_control);
}
else if(pl==Raising && limit_switch==off)
{
current_state=GEAR_UP;
printf("Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("Light is:%s\n",State_Machine[current_state].light);
printf("Landing Gear Hydraulic Control:%s\n",State_Machine[current_state].landing_gear_hydraulic_control);
}
else
{
RaisingGear();
}
}

void GearUp(void)
{
current_state=GEAR_UP;
printf("Enter the status of pilot's lever:");
fflush(stdout);
scanf("%d",&pl);
if(pl==falling)
{
current_state=CHECK_BEFORE_LANDING;
printf("Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("Light is:%s\n",State_Machine[current_state].light);
printf("Landing Gear Hydraulic Control:%s\n",State_Machine[current_state].landing_gear_hydraulic_control);
}
else
{
GearUp();
}

}

void CheckBeforeLanding(void)
{
current_state=CHECK_BEFORE_LANDING;
printf("Enter the status of pilot's lever and hydraulic mechanism status:");
fflush(stdout);
scanf("%d %d",&pl,&hm);
if(pl==falling && hm==working)
{
current_state=LOWERING_GEAR;
printf("Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("Light is:%s\n",State_Machine[current_state].light);
printf("Status of Direction valve:%s\n",State_Machine[current_state].direction_valve_status);
}
else if(pl==falling && hm==not_working)
{
current_state=LOWERING_GEAR;
printf("Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("Light is:%s\n",State_Machine[current_state].light);
printf("Status of Direction valve:%s\n",State_Machine[current_state].direction_valve_status);
printf("Status of gas pressurized Spring System:%s\n",State_Machine[current_state].Gas_Pressurized_Spring_system_status);
}
else if(pl==(Raising))
{
CheckBeforeLanding();
}
}

void LoweringGear(void)
{
current_state=LOWERING_GEAR;
printf("Enter the status of pilot's lever and limit switch:");
fflush(stdout);
scanf("%d %d",&pl,&limit_switch);
if(pl==falling && limit_switch==on)
{
current_state=CHECKING_BEFORE_TAKEOFF;
printf("Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("Light is:%s\n",State_Machine[current_state].light);
}
else if(pl==Raising && limit_switch==off)
{
current_state=GEAR_DOWN;
printf("Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("Light is:%s\n",State_Machine[current_state].light);
printf("Landing Gear Hydraulic Control:%s\n",State_Machine[current_state].landing_gear_hydraulic_control);
}
if(limit_switch==off)
{
LoweringGear();
}
}

void Initiate_State_Machine()
{
current_state==GEAR_DOWN;
printf("The Finite State Machine is Initialized and current the program is in""GearDown State & Light is:%s\n",State_Machine[current_state].light);
}

Output: