This Section Contains the Following Two Subsections

1Introductory Material

This section contains the following two subsections:

1.1 Executive Summary

1.2 Acknowledgements

1.1Executive Summary

The Senior Design Lab of the Department of Electrical and Computer Engineering at Iowa State University has been suffering a multitude of security breaches. Theft, unauthorized entry, unauthorized use of equipment, and increasing concern about vandalism are the main issues of concern. Presently, a numeric combination code is required to access the lab. This access code is provided to all senior design students to access and use the lab equipment. This security measure is vulnerable because this code can be passed by students to other unauthorized people. Furthermore, students have been allowing people without authorization to access the lab by holding the door open for them. In response to this practice, the Senior Design Lab has requested the design team develop a prototype system which provides a higher level of security for similar security scenarios. This security system must meet several criteria including authorized access only, prevention of multiple entries, occupant accountability, and alarm prevention.

The team has considered several possible approaches to the design of the prototype, and has decided upon a design that integrates several small and readily available consumer-grade components. Some of these components have been designed and built by the team, and are discussed later in this report.

To tackle the prime concern of authorized access only, the design team has decided to use an RFID kit from Phidgetsinc. This consumer level device can identify a user and pass the information to a PC via USB.

The other concern the design team faces is the multiple entry issue. After much consideration, the team has decided to use physical weight as a method of monitoring the number of occupants. An analog weight scale has been designed to communicate with a computer interface board via RS-232. The weight information for authorized personnel will be then matched with the unique RFID identification number to ensure access is only provided to the particular person and multiple entries will be prevented.

In order for the devices to interact and process relevant information, the team has written several modules of code that combine to create an overall security system that meets the requirements provided by Senior Design. These modules include RFID identification, weight verification, door sensing, database creation, and two way data communication threading between the database and software.

1.2Acknowledgements

The entrance security team would like to thank the senior design staff and faculty at Iowa State University for their assistance. The team would also like to thank Professor Mani Mina and Dr. Gregory Smith for the guidance they have provided through the planning, design, and implementation processes.

2Planning

The planning phase of this project consists of the following sections: preliminary project requirements, project solution plan, and planning review.

2.1Requirements Specification

This section contains a description of the problem as well as the functional and non-functional requirements that are part of that description. Furthermore, a solution is described that meets the given requirements. Finally, the project deliverables are discussed and explained.

2.1.1Problem Description

The team was to create a design for a security system that will only allow access for authorized individuals, and will prevent more than one person from entering at the same time.

2.1.2Intended Use

The intended use of this security system is to prove the concept that multiple entry and unauthorized access can be prevented using RFID tags and a weight scale as primary components. The system is not intended for actual use in the field, rather it is intended to show that such a system can be built.

The delivered system is also intended to be used to further prove this security system design by being modified to meet the non-functional requirements outlined in this document.

2.1.3Intended Users

This system is intended to be used by students enrolled in Iowa State University’s electrical and computer engineering senior design class. More specifically, it is intended to be used by the students assigned to the “Entrance Security System” project, senior design faculty and staff, and group advisors. These people will have a great deal of technical knowledge and will also have the tools needed to operate or expand the system. Furthermore, these users will have access to all technical documents concerning the entrance security system.

2.1.4Operating Environment

This project has been intended as a proof of concept for a theoretical security system. Therefore, the delivered system is intended to operate in a laboratory environment. This environment includes the following qualities:

• Temperature range from 18°C (64°F) to 23°C (73°F)
• Humidity range of 40% to 70% relative humidity
• Access to maintenance tools and measuring equipment
• Area security consisting of cameras and locks

2.1.5Problem Solution

In order to best solve the problem, a system was created using several preexisting security technologies. A summary of the technologies is listed below and will be further discussed in the following section.

• RFID Tags – Allow authorized access only
• Monitored Holding Area – Occupant flow control
• Weight Sensor – Determine number of occupants
• Alarm – Prevent security breach
• Software – Determine the event of a security breach

2.1.6Market Survey

There are many different technologies currently being implemented in security systems worldwide. RFID, retinal, fingerprint, vocal, and facial identification systems are many of the systems used to deter unauthorized access. There are, however, very few technologies used to prevent multiple entry. The leading systems currently in place usually involve security personnel, or some type of turnstile. These systems unfortunately are notoriously unreliable and are financially inefficient (costing a great deal for a small incremental amount of added security.)

Figure1: Turnstile security system A

Figure 2: Turnstile security system B

2.1.7Functional Requirements

The following are the client’s mandatory functioning requirements, which have been addressed by this system.

• Allow access to authorized personal only
• Prevent multiple entry during a single system access
• Trigger an alarm in the event of a security breach
• Log the username/date/time for each system use
• Log past security breaches and alarms

2.1.8Non-Functional Requirements

The following are the client’s ideal requirements which are non-functioning and are not specifically addressed by this system.

• Prevent theft of equipment
• Account for user possessions
• Mechanically deter security breaches

2.1.9Deliverables

Upon completion of this project, the following components were delivered.

• Mountable wall unit
• Circuit diagrams
• Logic and control software
• Computer input/output interface board
• RFID cars and compatible RFID scanner
• Weight sensor
• Project poster
• Final report
• Installation/Use instructions and documentation

2.2 Project Plan

This section outlines the administrative process that was required for this project including the work breakdown structure, resource requirements, and project schedule.

2.2.1Work Breakdown Structure

Table 1shows the breakdown of hours per person in the team.

Table 1: Personnel Effort Requirement (hours)

Task 1: Project Definition

This task included statement of the problem, requirements, and the specification made by the client.

Task 2: Technical Considerations

This task contained a list of technologies picked by the team that could be used in product design. It includes extensive research of each technology considered and the components needed to implement it. The team will selected the best technology that was feasible to approach the prototype design.

Task 3: End-Product Design

This task consisted of the design process for the system once a feasible technology was chosen. The end result was a well-designed concept that met the client’s requirement.

Task 4: End-Product Implementation

This task consisted of taking the concept design and implementing it.

Task 5: End-Product Testing

This task consists of testing the implemented design to ensure the prototype functions properly, and meets the client’s need.

Task 6: End-Product Documentation

Since documentation occurs throughout the entire project, this task was to ensure that all documentation was reviewed and logically assembled near the completion of the project.

Task 7: End-Product Demonstration

The task was to demonstrate the end product to the Industrial Review Board, the client, and the advisor.

Task 8: Project Reporting

This task involved creating a detailed report of the entire process, from problem definition to presentation.

2.2.2Resource Requirements

This section includes the total financial resources required for the project. Besides the material cost, the cost of labor was also calculated based on the hourly rate of $10.00. The information on Table 12 lists all items including parts, services, equipment, telephone, postage and printing costs.

Table 2: Product Cost analysis

Item / W/O Labor / With Labor
Parts & Materials
1. RFID Unit
2. Resistors (12)
3. Slide Switches (2)
4. USB Cables
5. Interface Board
6. Printing Circuit Board
7. Enclosures
8. Aluminum Tape
9. Weight Scale
10. Wires
Subtotal: / $ 70.00
$ 1.00
$ 4.00
$ 2.00
$ 50.00
$ 5.00
$ 5.00
$ 16.00
$ 45.00
$ 5.00
$ 203.00 / $ 70.00
$ 1.00
$ 4.00
$ 2.00
$ 50.00
$ 5.00
$ 5.00
$ 16.00
$ 45.00
$ 5.00
$203.00
Other Costs (from table 4) / $ 31.00 / $ 31.00
Labor at $12.00 per hour
Ali, Nahiyan
Chatergee, Shrabantee
Kumar,Vaibhav
Weigel, Alex
Zeng, Tao
Subtotal: / $ 234.00 / $ 2616
$ 2304
$ 2676
$ 2580
$ 2580
$ 12,756
Total Project Cost / $234.00 / $ 12,990

2.2.3Project Schedule

A timeline for the project is shown below in Figure 8.

Figure 3: Gantt chart of expected project time span

Figure 4: Revised Gantt chart of expected project flow and time span

Figure 10 below shows the deliverable schedule and it has not changed from the original chart in the project plan. The deliverables are mandated through the senior design class schedule.

Figure 5: Gant chart of schedule of deliverables

2.2.4Project Risk

The majority of the risk in the project is in the compatibility of the components to communicate with each other. The RFID sensor is of primary concern since the design team does not have the necessary skills to build a replacement. Also, there is a great deal of risk involved with the software. The team must learn to program in the correct language in order to properly use the interface board. Finally the remaining portion of foreseeable risk is the weight scale itself. Since the team was forced to build the electrical components of the scale, there is an increase concern of component or connections failure.

2.3Plan Review

The planning phase of the project schedule was completed successfully, but was not without some minor revision. The general system plan was proven to be adequate. The design phase was then able to take over and the initial planning gave it a suitable foundation.

3Design

The design phase was executed immediately following completion of the planning phase. This section of the report explains the detailed design.

3.1Engineering Specification

This section describes each of the different design areas and explains the details behind each area.

3.1.1System Description

The general system is composed of a compartment with two RFID security doors. Inside the compartment, there is a weight scale placed to determine the number of occupants and prevent the multiple entrances. Figure 1 shows an actual appearance of the compartment.

Figure 6: Actual appearance of the compartment

Both doors are monitored by a computer. When an authorized user activates the system by swiping an RFID tag, it is then recognized by the system. The computer then allows the door to be opened without alarm. In order to open the second door, a weight must be recorded by the compartment scale and must match the database. If the database entry and scale reading are not within the tolerance, an alarm will sound. Figure 2 shows a block diagram of the general system.

Figure 7: Block diagram of the general system

Since there are two RFID scanners (one at the first door, and one at the second door), the computer will take the signal that has been recognized first. If a user from outside the lab swipes the RFID tag earlier than the user from inside the lab, then the system will only operate as the entrance system; otherwise, it will only operate as the exit system. Figure 3 shows the state flow of this general system.

Figure 8: State flow of the general system

3.1.2Sub-systems

This system consists of the following three major subsystems:

• Entrance system
• Exit system
• Door switching system

3.1.2.1Entrance System

In order to enter the senior design lab, a user is required to swipe his/her RFID tag for his/her identification. The RFID scanner sends the data to the interface board controlled by the computer. Once the system has approved the entrance request, the interface board sends a signal to open the first door; otherwise the first door remains closed. The first door is able to open for only 10 seconds to allow the user to enter the compartment. If the door is not closed after 10 seconds, an alarm will sound. After entering the compartment, the user is required to stand on a digital weight scale, which measures the weight of the user. The weight scale will not send the data to the interface board until the system ensures that the first door has been locked. Once the logic is satisfied, the data is sent and compared to the previously recorded weight with a tolerance that is based on that particular users weight variance. If the weight is within tolerance, the second door will open; otherwise, the system will sound an alarm. Once the second door opens, the system sends a signal to the interface board to clear the recorded RFID number and set everything back to the initial state. The second door also remains able to open for only 10 seconds, otherwise an alarm will sound. If the user does not enter the lab within 10 seconds, the user has must exit the compartment and restart the entrance process. For some unpredictable reasons, if both doors happen to be open at the same time, the system will sound the alarm. Figure 4 shows a state flow of the entrance system.

Figure 9: State flow of entrance system

3.1.2.2Exit System

To exit the lab, the user must swipe their RFID card through the RFID reader from inside of the lab. Again, the second door remains open for only 10 seconds; otherwise it will sound the alarm. After 10 seconds has past, the weight scale sends the reading to the computer through the interface board. If the user is authorized, and is the only occupant, the first door will be made able to open and the user may exit the compartment. Figure 5 shows a state flow of the exit system.

Figure 10: State flow of exit system

3.1.3User Interface Description

This system is designed for two different types of users: Students, and System Administrators. The students will only need to be able to swipe their RFID card, listen to the voice commands given by the computer, and open doors. Meanwhile, system administrators will need to start/stop the software, and add/remove/change user weight and RFID cards.

3.1.3.1Student Interface

Students will be required to listen to simple voice commands given by the computer. Also, they will need to be able to swipe and RFID card over the RFID scanner (Figure 6 shown below.)

Figure 11: RFID Scanner

3.1.3.2System Administrator Interface

The system administrator control panel (Figure 7 shown below) is comprised of 2 sections: “RFID Reader Info” (left), and “Database (Right).” The “RFID reader info” is used to observe the operation of the RFID reader to insure that it is working properly. The “Database” section is used to add, modify, delete, and view database entries for user entry maintenance.

Figure 12: Entrance Security Control Panel

3.1.4Input/Output Specification

The peripheral components of the system are designed around the interface board. The interface board acts as a conduit for information between the user and the computer. As such, it is important to map all signals entering and exiting the interface board. Also, there exists communication between the RFID scanner and the computer directly. Figure 11 shows the system mockup from the planning phase.

Figure 13: System mockup from planning phase

Given the initial system plan, it was necessary to specify all the inputs and outputs for the system. A system communication breakdown is shown below.

Input

• RFID 1 (USB)
• RFID 2 (USB)
• Interface Board (RS-232 Serial)
• Door 1 Sensor (Digital)
• Door 2 Sensor (Digital)
• Weight Scale (Analog)

Output

• Alarm (Audio)
• Voice Commands (Audio)
• Interface Board Operational LED

Figure 12 shows a diagram of how each component communicates in the system.

Figure 12: Detailed Signal Design

3.1.5User Interface Operational Specification

This section is intended to show how the user is to interact with the system. The following figure series (Figure 13) explains the entrance process. The exit process is simply the reverse of the entrance process.