Project 2 - Implement the Code for controlling the retraction and extension of Airplane’s landing gear
Overview of the Project:
In this project, controlling the retraction and extension of the Airplane’s landing gear can be implemented using a Finite State Machine (FSM). FSM is the most efficient algorithm which is a mathematical model of computation.
Goals
- Controlling the direction of the Valve.
- Controlling the retraction and extension of the Airplane’s landing gear.
Key Highlights of the Project:
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:
Implementing the control for the retraction and extension of the Airplane’s landing gear using the Finite state machine with the knowledge of various states of switch and gear.
Expected Outcomes:
The student will be getting the Knowledge of the Finite State Machine algorithm which is used to achieve control over the retraction and extension of the Airplane’s landing gear using the switch and gear states of the Airplane.
PROGRAM CODE
#include<stdio.h>//Header file
#include<States.h>//Created header file
static void (*state_table[])(void)={Gear_Down,Checking_Before_Takeoff,Raising_Gear,Gear_Up,Checking_Before_Landing,Lowering_Gear};
//Variables
int main()
{
Init_State_Machine();//Function calling
while(1)//Loop
{
state_table[current_state]();
}
return 0;
}
/*
* States.h
*/
#ifndef STATES_H_
#define STATES_H_
#include<stdio.h>
void Init_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
{
//States
GR_DWN,
CHK_BFR_TKFF,
RSING_GR,
GR_UP,
CHK_BFR_LND,
LWRNG_GR
}State_Type;
typedef enum Switch {
Open,
Close//Plane is in ground
}Switch_Status;
typedef enum Pilot_Lever
{
Rising,
Falling,
UP,
DOWN
}Pilot_Lever_Status;
typedef enum Hydraulic_Mechanism
{
Working,
Malfunctioning
}Hydraulic_Mechanism_Status;
/* -input for changing the State----- */
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"},
{"Raising Gear", "Red", "Up", "Enabled"},
{"Gear Up", "Off", "0","Disabled"},
{"Checking Before Landing", "Red", "Down", "Enabled"},
{"Lowering Gear", "Green", "Down", "Enabled"}
};
#endif /* STATES_H_ */
/*
* Gear_Down.c
*/
#include<States.h>
void Gear_Down(void)
{
current_state = GR_DWN;
printf("\nCurrent State: %s\n", State_Machine [current_state]. current_state_indication);
printf("\nEnter 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("\nCurrent State: %s\n", State_Machine [current_state]. current_state_indication);
printf("Light Status: %s\n", State_Machine [current_state].light_status);
}
else
{
Gear_Down();
}
}
/*
* Lowering_Gear.c
*/
#include "States.h"
void Lowering_Gear(){
//State
current_state = LWRNG_GR;
printf("\nCurrent State: %s\n",State_Machine[current_state].current_state_indication);
printf("\nEnter the Limit Switch Status, Pilots Leaver Status:");
fflush(stdout);
scanf("%d %d",&limit_switch,&pilot_lever);//taking i/p from the user
if(pilot_lever == Rising)
{
current_state= CHK_BFR_TKFF;
printf("\nCurrent 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)
{
current_state= GR_DWN;
printf("\nCurrent 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);
}
if(limit_switch == Close)
{
Lowering_Gear();
}}
/*
* Init_State_Machine.c
*/
#include "States.h"
void Init_State_Machine()//func
{
//System Initialized and its in State A
current_state = GR_DWN;
printf("\nState Machine is initialized & Program is in Gear_Down State & Light Status",State_Machine [current_state].light_status);
}
/*
* Checking_Before_Takeoff.c
*/
#include "States.h"
void Checking_Before_Takeoff()//func
{
current_state = CHK_BFR_TKFF;
printf("\nCurrent State : %s\n",State_Machine[current_state].current_state_indication);
printf("\nEnter 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("\nWait 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("\nCurrent 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("\nCurrent 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[hydraulic_mechanism]);
}
}
/*
* Gear_Up.c
*/
#include "States.h"
void Gear_Up()//func
{
current_state = GR_UP;
printf("\nCurrent State: %s\n",State_Machine[current_state].current_state_indication);
printf("\nEnter the Pilot's Lever Position:");
fflush(stdout);
scanf("%d",&pilot_lever);
if(pilot_lever == Falling)
{
current_state = CHK_BFR_LND;
printf("\nCurrent 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();
}
}
/*
* Raising_Gear.c
*/
#include "States.h"
void Raising_Gear()//func
{
current_state = RSING_GR;
printf("\nCurrent State : %s\n",State_Machine[current_state].current_state_indication);
printf("\nEnter the Limit Switch Status,Pilots Leaver Status:");
fflush(stdout);
scanf("%d %d",&limit_switch,&pilot_lever);
printf("\nWait for 1 sec\n");
if(pilot_lever == Falling && limit_switch == Open)
{
current_state = CHK_BFR_LND;
printf("\nCurrent 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("\nCurrent 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();
}
}
/*
* Checking_Before_Landing.c
*/
#include "States.h"
void Checking_Before_Landing()//func
{
current_state = CHK_BFR_LND;
printf("\nCurrent State: %s\n",State_Machine[current_state].current_state_indication);
printf("\nEnter 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("\nCurrent 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("\nCurrent 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);
}
if(pilot_lever == (UP || Rising || Falling))
{
Checking_Before_Landing();
}}OUTPUT
State Machine is initialized & Program is in Gear_Down State & Light Status
Current State: Gear Down
Enter the Pilot's Lever Position and Squat Switch Status:0 0
Current State: Checking Before Take Off
Light Status: Green
Current State: Checking Before Take Off
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 Valve Status: Up
Current State : Raising Gear
Enter the Limit Switch Status, Pilots Leaver Status: 1 2
Wait for 1 sec
Current State : Gear Up
Light Status: Off
Hydraulic Control for Landing Gear Status: Disabled
Current State: Gear Up
Enter the Pilot's Lever Position: 1
Current State: Checking Before Landing
Light Status: Red
Hydraulic Control for Landing Gear Status: Enabled
Current State: Checking Before Landing
Enter the Pilot's Lever Position and Status of Hydraulic Mechanism:3 0
Current State: Lowering Gear
Light Status: Green
Direction Valve Status: Down
Current State: Lowering Gear
Enter the Limit Switch Status, Pilots Leaver Status: 0 1
Current State: Gear Down
Light Status: Green
Hydraulic Control for Landing Gear Status: Enabled
Current State: Gear Down
Enter the Pilot's Lever Position and Squat Switch Status: