ECE 477 Digital Systems Senior Design Project Spring 2007

Homework 4: Packaging Specifications and Design

Due: Friday, January 26, at NOON

Team Code Name: Hazardous Rover Group No. 10

Team Member Completing This Homework: Azad Affif Ishak

e-mail Address of Team Member: aishak@ purdue.edu

Evaluation:

Component/Criterion / Score / Multiplier / Points

Introduction

/ 0 1 2 3 4 5 6 7 8 9 10 / X 1
Commercial Product Packaging / 0 1 2 3 4 5 6 7 8 9 10 / X 3
Project Packaging Specifications / 0 1 2 3 4 5 6 7 8 9 10 / X 2
PCB Footprint Layout / 0 1 2 3 4 5 6 7 8 9 10 / X 2
List of References / 0 1 2 3 4 5 6 7 8 9 10 / X 1
Technical Writing Style / 0 1 2 3 4 5 6 7 8 9 10 / X 1
TOTAL

Comments:

Comments from the grader will be inserted here.

1.0  Introduction

The project is to build a model of a surveillance vehicle that could be used in dangerous areas where humans could not normally go. However, if it were to be assembled for real usage, a more durable vehicle’s components are needed.

The vehicle will have many external peripherals on board. Therefore, it must be designed in such a way that the electronic components together with other parts are protected while still allowing the car to freely move. The car will also be mounted with a robotic arm which can pick up small objects with the assist of live video feed from the wireless camera to the web interface. Careful consideration must be taken while designing the vehicle especially in two critical areas which are compartment space and stability. In order to better understand the design considerations, we will discuss two commercially available products.

2.0  Commercial Product Packaging

The following is an analysis of two commercial products that have some similar concepts to the Hazardous Rover project. Positive and negative aspects of the product’s packaging will be discussed and some constructive aspects might be adapted to our project.

2.1  Product #1

Figure 1: Talon Robot

Product one is a military robot the Talon designed by Foster-Miller incorporation [6]. The robot is made of stainless steel and use track system which made it very sturdy. Since it will mostly be used for military practical usage, it has many features that resemble a military tank. A portable control unit will be used to communicate wirelessly with the robot. The robot uses a high cost lithium battery for a long battery life. It is also designed to hold various types of arsenal depending on the mission.

The vehicle is known for its superb speed among other commercially available military robots. This advantage is indeed an important characteristic of a military vehicle. It also has additional navigation aides such as infrared and night vision video which is to be expected. Talon can travel on sand, snow and even drive up stairs. All these advantages will be the trade off for its expensive cost which is around $60,000.

There are too many features can be adapted to Hazardous Rover but might not be practical for a model vehicle. Talon uses high quality wireless camera system which is good since the human operator needs to be able to see clearly via the web interface to control Hazardous Rover. Other feature which is applicable to our project would be the microphone and speaker.

2.2  Product#2

Figure 2: Inspection Robot

Product 2 is an inspection robot by Danduct Clean [7]. The robot looks resembles a small RC car and is used to inspect air dusts for ventilation problem. As can be seen from figure 2, the vehicle is not a wireless product. It has a 33m communication cable connected at the back of the vehicle. The operator can control it by using a control box that has a joystick and other switches and a live video feed can be previewed on an external monitor such as the television.

The car is 215mm long, 190mm wide, 110mm high and weights about 3 kg. The car is so small that made it perfect for usage in small areas. Two cameras are mounted at the front and at the back which gives a good view for inspection. However, there are couples of disadvantages of the vehicle. Firstly, it is not wireless which made it has a limited range of application. The camera could not be controlled to pan or to tilt.

3.0  Project Packaging Specifications

The Hazardous Rover will still hold the appearance of a hummer with a few modifications. Starting from the front part of the vehicle, a robotic arm will be mounted on the vehicle. A sturdy plastic platform will be extended from the middle of the car to the front so that the arm’s base can be placed. By having a 6lb of weight at the front of the vehicle, the vehicle need to be designed in such a way weight balancing can be achieved. The main circuitry (PCB) will be placed in the middle of the vehicle because it will be the center of mass of the car.

The Hummer is 13 inch wide and 15 inch long, a pretty big vehicle for an RC car. The tires are 4.8 inch diameter long and indeed will support the stability of the car. The antenna of the wireless bridge will be protruding from the roof in the rear section of the vehicle. The internet camera will be mounted on top of the car. For a better visibility for the arm and also the vehicle, it will be expanded about 3 inches upward from the roof of the car. Two servos will be driving the camera so that it can be moved 180 degrees.

The battery will be placed at the back of car for weight balancing, inside the car behind the rear wheel to be exact. Another practical reason for having the battery at the back is for the effortless way to charge the battery without removal. All the details of each component will be summarized in the summary section. The best way to see the packaging of the vehicle is by contemplating the scale CAD drawing illustration of the size and shape in appendix A.

4.0  PCB Footprint Layout

Appendix C is the basic PCB footprint layout of the project. The PCB will contain headers for the pan and tilt servos and will contain through holes for the remainder of the external PCB wire connections so that wires can be soldered directly to the PCB. The estimated PCB size is 4.5 inches long and 5 inches wide.

5.0  Summary

The 4.8 diameter long tires and pretty big chassis of the hummer will allow for enough strength and durability. The main focus of the packaging design will be the compartment to fit various parts on the vehicle. Fortunately, the hummer’s shell is large and empty inside where the wireless bridge, battery, and PCB can be placed beneath it. Proper weight balancing is also crucial to determine the smoothness operation of the vehicle. A test was conducted to test the load that the vehicle can hold while still moving at the average speed. 13 pounds of load were placed onto the car and it successfully carried them. Various packaging improvements could be implemented to Hazardous Rover such as a more sturdy shell. However those improvements will add to the cost of making this model. Some changes to the current packaging might occur later when assembling the real parts together. Theoretically the placements of the parts in this homework will work but practically it might not.
List of References

[1] Freescale, MC9S12NE64 Microcontroller Datasheet

http://cobweb.ecn.purdue.edu/~477grp10/documents/MC9S12NE64V1.pdf

[2] D-Link, DCS-900W Wireless Internet Camera

http://www.dlink.com/products/?pid=297

[3] Power-Sonic, PS-1230 Rechargeable 12V 3.0 AH Battery http://shay.ecn.purdue.edu/~477grp8/datasheets/ps-1230.pdf

[4] D-Link DWL-G820

http://www.newegg.com/Product/Product.asp?Item=N82E16833127153

[5] Robotic Arm Trainee

http://www.robotstore.com/store/product.asp?pid=128&catid=11

[6] Foster-Miller. (2006) “TALON ROBOTS”

http://www.fostermiller.com/lemming.htm

[7] Danduct Clean, Inspection Robot

http://www.danduct.com/Inspect.html


Appendix A: Project Packaging Illustrations

1. Mechanical Arm

2. Wireless Bridge

3. Battery

4. PCB

5. Wireless Camera

6. Lights


Appendix B: Project Packaging Specifications

Tooling Requirement

The construction of the Hazardous Rover requires basic tooling tools. Below is the list:

·  Screw drivers

·  Soldering and de-soldering equipment

·  Wire strippers

·  Cutting tools (for plastic)

Table 1 show the weight and cost requirements for the main parts of Hazardous Rover.

Component / Weight (lbs) / Price / Quantity
Freescale microcontroller and PCB [1] / 1 / $98 / 1
Webcam D-Link DCS-900W[2] / 5 / $90.00 / 1
Wireless Bridge DWL-G820 [4] / 2 / $58.00 / 1
Robotic Arm Trainee [5] / 6 / $80.00 / 1
Power Sonic Battery [3] / 3 / 14.91 / 1
Pan tilt / 1 / $39.95 / 1
Motors / 0.5 / $5.50 / 2
Total: / 18.5 / $386.36

Table 1: Weight and Cost requirement
Appendix C: PCB Footprint Layout

Figure 4: PCB Footprint layout of Hazardous Rover

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