Vehicle Sensor Control for Parking Lot Management System

INTRODUCTION

As the title indicates the goal of the project was to develop a parking lot management system. In this project we had reduced our project into 5 design phases. In order to acheive the goal, we encountered with some problems and we made progress compared to the 1st and 2nd phase progres report.

As already accompanied with this report, we done VHDL code for the parking lot management system based on the state machine and Seven segment diplay was provided for debuging purpose. These modules were tested separately working in proper sequence relative to the timing diagram.

From the test result, the system has to increment whenever a car is coming in to the parking lot. When a car leaves, the system has to decrement by 1 from the total count(# of car in parking lot). In stead of assuming parking lot is infinite, we restricted the limit of parking spot (7 for max and 0 for min) and elminiate the internal error of system (# of parking spot < 0).

SPECIFICATION

• CLK
• S_en (signal for enterance from the sensor)
• S_ex (signal for exit from the sensor)
• Reset (for reset the system and turn system on)

• So_en (solenoid enable signal for entrance)
• So_ex (solenoid enable signal for exit)
• 7 segment display

Whenever a car is approaching to the gate for the entrance, a signal from the sensor for the entrance (S_en) is fired off to the system then the system checks if a parking lot is not full. If the parking lot is not full the system enable the solenoid to open the gate. The system makes an increment in the count of the car and displays the result. Whenever a car is approaching to the gate for the exit, a signal from the sensor for the exit (S_ex) is fired off to the system then the system opens the gate. The system makes a decrement in the count of the car and displays the result.

BLOCK DIAGRAM

SCHEMATIC DIAGRAM

TIMING DIAGRAM

A structured logic device description

CIRCUIT DESCRIPTION

The system has seven states all together.

• Idle state: The state is reset first; the state remains in this state if both inputs from Hall effect sensor S-en = 0 and S-ex = 0. Otherwise it goes the next state
• Signal entrance state: At this state the system makes sure if a parking lot is not full.
• Signal exit state: At this state the system makes sure if any car is left before it opens the gate. So that it does not count negative number.
• Solenoid entrance state: From signal entrance state once it is checked that the parking lot is not full, (S_en = 1) it enables the solenoid for the entrance and makes the proper count increment. The result is displayed by the display condition state.
• Solenoid exit state: From signal exit state once it is checked that the parking lot is not empty, (S_ex =1) it enables the solenoid for the exit and makes the proper count decrement. The result is displayed by the display condition state.
• Display condition state: The count of the car is always displayed by this state.
• Signal state: Once the car is exited or entered, the system has to close the gate, which disables solenoid exit state and solenoid entrance state respectively.

We had a problem to enable the solenoid from the the Hall effect sensor signal output. because the output signal was not enough to show, when the solenoid is enabled to open the gate.

we had a problem when we write the code, however with the help of our professor we managed to fix the problem easily.

SUMMARY

A signal from a sensor, to be specific from Hall Effect Sensor, fired off to the system, the system has to be able to identify and respond if the signal is for entrance or exit.

If the signal is for entrance(from entrance sensor), the system has to make sure if the parking lot is not full (If Parking spot is left) before it opens the gate. If the parking is not full, any spot is left, it has to open the gate, make the proper count increment and display the result. If the signal is for exit (from exit sensor), the system has to open the gate, make the proper count decrement and display the result.