Detailed Project Plan

Engineering 8936

Term 8 Design Project

Autonomous Hovercraft

Dr. Andy Fisher

January 17, 2012

Colin Abbott 200621837

Blair Hunter 200642791

Colin Oldford 200717783

Michael Simmonds 200617777 Table of Contents

List of Figures

List of Tables 1.0 Project Scope

The scope of this project is to complete research that will lead to the design and construction of an autonomous hovercraft. The hovercraft will have the ability to maneuver a path that will contain multiple obstacles. This hovercraft can then be used to find an object or give video surveillance and return to its initial launch point. Once the craft is successful at navigation and surveillance, the next step would include making the craft optionally controlled by Bluetooth. Achieving these goals will lead to the ability to use the hovercraft as a surveillance device or an early scout to see up ahead.

2.0 Research

Research into a number of items is a key component to the success of our autonomous hovercraft. Completing proper research will aid us in making proper selections with regards to electronic hardware, control strategies and hovercraft construction. In addition to our own independent research, we also have Professor Hinchey as a valuable resource. As this project was used previously in a Term 7 design project we have the benefit of learning from their mistakes and will be able to avoid those with our design. Research categories are as follows:

• Investigation of past issues with Term 7 hovercraft including but not limited

to: problems with indoor use of compass and hovercraft skirt construction.

• Types of available sensors: Pros and cons of particular types,

microcontroller interfacing, cost, power requirements etc.

3 • Programming and controls strategies: PID control, non-linear controls.

• Hovercraft construction: traditional hovercraft skirt vs. Non-traditional

materials such as foams or hard rubbers, potential for a rapid-prototyped casing

• Surveillance and communications: Addition of a surveillance camera,

potential control using a Bluetooth interface

Research shall be completed by studying past designs as well as consultation with

Professor and other faculty that assisted during the previous Term 7 project. The internet will also be a significant resource for researching as well as text books made available by Professor Hinchey.

3.0 Simulation

We will also be making use of Matlab and Simulink to run simulations of our hovercraft control system. In particular we will be studying how the hovercraft behaves when going around a corner, the affects of different system variables, control strategies and gains.

Studying the affect of system constants, including weight, weight distribution, prop thrust, and friction will aid in determining specifications for our hovercraft such as material choices, size and shape. We will also be able to determine the best control strategy, for example using proportional or PID control and the affect of non-linear sensors.

Using the free body diagram of the hovercraft during a turn, we have already determined the system block diagram and created a simulink simulation. We have also created matlab M-codes capable of producing time stepping simulations using the

4 system partial differential equations as well as to generate root-locus plots for various system variables. We are currently completing our simulations concurrently with research.

4.0 Testing Phase

The testing process will be divided into 2 subsections which will have subsequent subsections.

4.1 Phase 1: Materials Selection

Testing will be performed during the selection process for the materials used for the hovercraft. During the materials selection phase the follow (but not limited to) components will be test: The main body of the hovercraft, The material to be used for the propellers, the material to used for the skirt and finally the material to be used for the aerodynamic fairing.

4.2 Phase 2: Equipment Selection

Upon the completion of the materials selection phase the equipment selection phase will begin. The phase will involve the selection of the major components of the hovercraft.

4.2.1 Motors

The motor(s) selection will be determined based on the results of the materials selection phase. The drive motor(s) will have to be able to produce an appropriate amount of torque for the propellers selected to allow for a varying range of speeds. The lift motor will have to produce a certain RPM for an extended period with minimal electrical draw.

5 4.2.2 Propellers

The propeller(s) design will be required to produce maximum thrust while minimizing the weight of the material used.

4.2.3 Electronics Selection

The electronics selected for this project will consist of the following: battery, micro controller, and a number of sensors whose usage will be determined as the project progresses.

5.0 Build Phase

The build phase will be divided into two separate portions.

5.1 Conceptual Phase

The conceptual phase of this project will involve modeling the components of the hovercraft in a CAD program. This will help to determine if there are any issues and allow for experimentation prior to the construction of the hovercraft. Some of the issues that may be encountered on this project are: interferences, weight, and placement of components. The conceptual model can be used to determine the required amount of thrust required for the hovercraft in addition to the optimal weight distribution for the vehicle. Figure 1 contains a rough conceptual model.

6 Figure 1 - Conceptual Drawing of Hovercraft 5.2 Construction Phase

The construction phase will be an ongoing process. The materials and components used for the physical construction of the hovercraft will be previously determined from the testing phase and conceptual phase. If required the rapid prototype can be used for the construction of parts.

5.3 Programming Phase

The hovercraft will have to be programmed to meet the requirements of the scope will utilizing the sensors that have been selected. This phase will require troubleshooting adjustments to our initial code to ensure we get the best performance from our hovercraft.

7 6.0 Project Risks

Possible risks that may be faced by the project team as the project advances include safety, environment, ethics, cost, and schedule risks. We have identified some foreseeable risks and mitigation measures.

6.1 Safety Risks

Safety is the number one priority of this project team. Some risks that we have identified are exposed propellers on our hovercraft, exposed electronics, battery misuse and sharp corners. To mitigate the safety risks posed by the exposed propellers and electronics we will design guards and casings to cover these items. Batteries used will be lithium ion which have a high energy density can be dangerous. They shall be used as recommended by the manufacturer such as proper charging and avoiding excess heat. All sharp corners or any other potential hazards will be identified and fixed. All sharp corners will be rounded to mitigate the hazard.

6.2 Environmental Risks

The biggest environmental risk that we have identified for this project is the use of batteries. We will research the proper disposal procedures and also the proper procedure if there is a spill.

6.3 Ethical Risks

The only ethical issue that we have identified is the chance of improper use. Our project group will only use our project properly and only for this project. Once the project is finished, we will properly dispose of the hovercraft.

8 6.4 Cost Risks

Like any project, there is the risk of going over your budget. We will try to mitigate this by having a contingency and planning our project based on it. We will try to use existing parts from previous attempts at making a hovercraft which will diminish the amount of new parts that we will have to purchase. Table 1 contains an inventory of the existing parts that are available to us. Table 2 contains a breakdown of the budget and contingency plan.

Table 1 - Inventory of Available Parts

Inventory of Parts ITEM NUMBER Bluetooth Chip 1 Tire Tubes 2 Lift Fan Blades 3 Drive Fans with Guards 3 Collars 7 Wrenches 4 Allen Keys 3 Toy Hovercraft 3 Experimental Foam Hovercraft 1 Old Term 7 Hovercraft 1 Screwdriver 1 Ratchet Wrench 2 Motor Mounts 4 Motor 1 Stepper Motor 1 Charger 1 Glue Sticks Multiple Filter 1 Random Circuit Boards 4 Bungee Cords Multiple Capacitors Multiple Resistors Multiple

9 Connectors Multiple 15000 mAh LiPa Battery 1 2200 mAh LiPa Battery 6 5000 mAh LiPa Battey 4 10000 mAh NiMH Battery 2 5000 mAh NiMH Battery 2

Table 2 - Budget Breakdown

Funds Acquired From Amount in $ Faculty of Engineering 250 Group Members 40 Contingency Group Members 20 Total 310

The above funds will be used to purchase all required new parts. Many parts will be acquired from already used parts that members of our team have from previous projects as well as from professor Hinchey who has some of the parts from a prior attempt at this project. Memorial Universities Faculty of Engineering, Mechanical department is allowing us to use $250 worth of funds within the department which will assist us with construction and supply of any materials needed. Also each group member has decided to put in $10 dollars of their own money for any other parts that we may not be able to acquire from the above mentioned means for a total of $40 from the group. Also to make sure we can fit the project within our budget and not go over we decided to add

$5 more from each member to make up a contingency of $20 for any unforeseen purchases or circumstances. In total we will work with a budget of $310.

10 6.5 Schedule Risks

Any project can run the risk of running behind schedule. The best way to mitigate this risk is to leave a few weeks at the end of your schedule to allow for any problems that may occur as the project progresses. We can also mitigate schedule overruns by closely adhering to the project schedule and also having good communication between all project members.

7.0 Project Management

In order to complete this project on time, the project group developed a schedule to follow by using a Gantt chart. The initial Gantt chart is contained in Appendix A. The project team will adhere very closely to this schedule and will make updates weekly.

The project team will meet daily to discuss the project progress and deal with any issues each member will have. The project team will also meet weekly with our supervisor to keep him updated with the project progression and to ask any questions that any project team member may have.

11 Appendix A

Project Schedule