Project Plan Rev. 0.1 Page 2
Project Bluebird
University of Portland / School of Engineering Phone 503 943 73145000 N. Willamette Blvd. Fax 503 943 7316
Portland, OR 97203-5798
Project Plan
Project Osprey: RC-VTOL
Contributors:
Aaron Duane
Jesse Fledderjohann
Hilary Henderson
Chris Hope
Approvals
Name / Date / Name / DateDr. Ward / Mr. Walt Harrison
Insert checkmark (√) next to name when approved.
University of Portland School of Engineering Contact: Karen Ward
Project Plan Rev. 0.96 Page 20
Project Osprey
Revision History
Rev. / Date / Author / Reason for Changes0.90 / 10/29/07 / Team Osprey / Initial draft
0.91 / 10/31/07 / Team Osprey / First faculty advisor revisions
0.92 / 11/4/07 / Team Osprey / Second faculty advisor revisions
0.93 / 11/5/07 / Team Osprey / Third faculty advisor revisions
0.95 / 11/5/07 / Team Osprey / Submitted to Industrial Representative
0.96 / 11/7/07 / Team Osprey / Revisions from Industry Representative
University of Portland School of Engineering Contact: Karen Ward
Project Plan Rev. 0.96 Page 20
Project Osprey
Table of Contents
Summary 1
Introduction 2
Background 3
Product Overview 4
General Description 4
Project Overview 4
Block Diagram 4
Deliverables 6
Introduction 6
Hardware Deliverables 6
Telemetry sensors and transmission 6
Output of Control Responses to Transmitter 7
Software Deliverables 7
Display of Telemetry Data 8
User Input 9
Mathematical Interpretation of User Input 9
Development Process 10
General Approach 10
Task and team organization 10
In-process testing 10
Individual design strategies 10
Block diagram 10
Risks/ Contingencies 12
Parts cannot integrate 13
Not meeting milestones 13
Not completing tasks on time 13
Unstable flight hardware 13
Cannot combine video & data display 13
Unreliable control radio link 14
Insufficient Telemetry radio 14
Milestones 15
Schedule 15
Overview 15
Resources 18
Budget 18
Conclusions 19
Appendix A: Glossary 20
Glossary 20
List of Figures
Figure 1: Block Diagram of Project Osprey 5
Figure 2: Overall Development Process 11
Figure 3: Osprey schedule part 1 16
Figure 4: Osprey schedule part 2 17
University of Portland School of Engineering Contact: Karen Ward
Project Plan Rev. 0.96 Page 20
Project Osprey
List of Tables
Table 1: Hardware deliverables 6
Table 2: Software Deliverables 8
Table 3: Project Osprey risks and contingencies 12
Table 4: Key Osprey Milestones 15
Table 5: Overall Osprey budget 18
University of Portland School of Engineering Contact: Karen Ward
Project Plan Rev. 0.96 Page 20
Project Osprey
Chapter / Summary1
Project Osprey will build a system to control a remote controlled model vertical takeoff and landing airplane as well as display information such as attitude and a camera feed to the pilot. This will be accomplished in four parts: pilot inputs and joystick reading, computer outputs and interface with transmitters, telemetry sensors and transmitter, and telemetry receiver and data display. Since each of these parts can be designed and tested individually, they will be developed in parallel. The joystick and computer output sections will then be combined, as will the telemetry systems, and those two parts will be tested together. Finally, the whole system will be integrated and tested. This is done because individual testing and debugging is much easier than testing and debugging an entire system.
The project schedule can be found in Chapter 5: Development Process. The project is scheduled for completion around March 21 2008. The budget for this project is also in Chapter 5, and comes to a total of about $2066.
University of Portland School of Engineering Contact: Karen Ward
Project Plan Rev. 0.96 Page 20
Project Osprey
Chapter / Introduction2
This document is designed to give the reader an overview of the process that will be used by Team Osprey to produce the deliverables defined both in this document as well as in Project Osprey’s functional specification. It also outlines the schedule that the project development process will follow, and gives a budget for the project. It will be useful to anyone with an interest in the process used to create Project Osprey’s deliverables.
Chapter 3: Background explains what the project is and why it is useful.
Chapter 4: Product Overview reviews the functional specifications and requirements for the project.
Chapter 5: Development Process gives information about the process that will be used to complete the project, including schedule information, a budget, and a list of personnel and their functions.
University of Portland School of Engineering Contact: Karen Ward
Project Plan Rev. 0.96 Page 20
Project Osprey
Chapter / Background3
Vertical takeoff and landing, or VTOL, bridges the gap between horizontal-only and vertical-only aircraft. Vertical-flight-only aircraft, such as helicopters, can take off and land in very small areas, but they are not particularly efficient or fast for traveling long distances. Horizontal-only aircraft such as normal fixed-wing airplanes can travel long distances efficiently and rapidly, but they require a long runway to take off and land; this limits the number of locations from which they can operate. VTOL combines the ability to fly long distances while configured as a fixed-wing aircraft with the ability to change configuration and land vertically like a helicopter.
Hardware already exists (as part of a mechanical engineering senior design project) for a remote-controlled VTOL model airplane. It is configured with two pairs of wings in tandem, with a brushless electric motor and a propeller attached in the center of each wing. The wing and propeller assemblies are rotated between horizontal and vertical by servos. By controlling the speed, and therefore thrust, of each of those four electric motors, and by controlling the pitch of each wing, the airplane can be piloted.
One of the challenges to successful VTOL aircraft is the fact that the control inputs need to produce different outputs depending on flight mode. For example, imagine that the pilot wants the nose of the aircraft to pitch downward. Whether in vertical flight mode or horizontal, the pilot does this by pushing forward on his flight control joystick. However, the aircraft must decide what to do: if it is flying in vertical mode, it must increase thrust in the back of the airplane and decrease thrust in the front, causing it to pitch forward; if it is in horizontal mode, it must increase pitch on the rear wings and decrease pitch on the forward wings to create the same effect. Project Osprey’s functional specification describes in more detail the appropriate responses for all desired movements.
Another challenge, one unique to remote-control aircraft design, is the perspective change that occurs due to the pilot having a fixed view of the airplane. When it is flying away from the pilot, all the controls are the same direction for the pilot and the plane. However, when the aircraft is returning to the pilot, facing him, the left and right sides of the plane are reversed, so a command from the pilot to roll to his left results in the airplane rolling to the pilot’s right. This can be very confusing, especially for an inexperienced pilot. Precise control also becomes very difficult as the distance between the pilot and the aircraft increase and the pilot is less able to see the airplane clearly. The camera system will allow the pilot to operate the aircraft beyond effective visual range of the pilot.
To reduce the complexity and time requirements of this project, commercially available hardware and software will be used whenever possible and appropriate. This reduces the time spent on redesigning specific pieces of the project and increases time available for integrating the pieces of the project, working on optional refinements, and giving the pilot time to practice flying the airplane before it is demonstrated.
University of Portland School of Engineering Contact: Karen Ward
Project Plan Rev. 0.96 Page 20
Project Osprey
Chapter / Product Overview4
General Description
Project Overview
The purpose of this project is to provide a means for a pilot to control a radio-controlled vertical take-off and landing airplane and to provide the pilot with information about that airplane’s state. The pilot’s control inputs are captured by a joystick, then processed by a laptop and output to a radio control transmitter which interfaces directly with a receiver on the plane, thereby controlling the physical hardware onboard. The state of the aircraft will be sensed by a gyro and an altimeter and transmitted back to the pilot through a telemetry radio link. Video information will also be sent back to the pilot by another radio link. The video information will be displayed to the pilot on the screen of the laptop, along with a graphical attitude/altitude display. The pilot will use this information to fly the aircraft.
Block Diagram
The diagram below illustrates the relationships between the different components of the project and how the pilot interacts with it. Gray boxes are hardware that will be located with the pilot on the ground, blue boxes are hardware located onboard the aircraft, and red arrows are radio links.
Figure 1: Block Diagram of Project Osprey
Deliverables
Introduction
The following sections use tables of deliverables to present information more clearly. The items are numbered by table and line. For example, item 2-4 is the fourth item in the second table. Hardware is discussed first, followed by software.
Hardware Deliverables
Table 1: Hardware deliverables
Item / Part / Brief Description1-1 / Radio receiver / Takes input from pilot controls and interfaces with transmitters, servos, motors
1-2 / Telemetry sensor- Gyroscopes / Gyroscopes, with no more than 5º drift away from intended direction while in flight
1-3 / Telemetry sensor- Altimeters / One barometric altimeter for altitudes above ten feet and an ultrasonic altimeter for altitudes less than ten feet.
1-4 / Telemetry sensor-Camera / Mass less than 6 oz., 480 lines at 30 Hz or better camera with transmitter
1-5 / Telemetry transmitter / Mass less than 5 oz., transmitter capable of transmitting sensor data to receiver on ground at a minimum distance of ¾ mile.
1-6 / Telemetry receiver / USB compatible receiver to accept data
1-7 / Camera transmitter / Mass less than 8 oz., transmitter able to send camera data to receiver on ground at a minimum distance of ¾ mile.
1-8 / Camera receiver / USB compatible receiver takes the transmitted camera signals and prepares them to be analyzed by the computer for display.
Telemetry sensors and transmission
The sensors and telemetry equipment are located on the plane and will transmit the data to the receiver on the ground and be processed and displayed for the pilot on the computer screen. The sensors that are going to be used are listed in the above table and then described in more detail later in this section.
After all the inputs from the human interface have been analyzed in the computer, they are transmitted from the computer by two four-channel transmitters using aircraft radio control frequencies. Onboard the plane, the signals are received by a radio receiver (Item 1-1) which then control the appropriate servos and motors.
There are several different sensors that measure the condition of each of the various motors and control surfaces. The gyroscopes (Item 1-2) will work together to make sure the pilot is able to determine plane’s attitude as well as determine the rate of change so the pilot can know how fast the plane is changing direction.
There are two different kinds of altimeters (Item 1-3) that will be used in the aircraft, a barometric altimeter that will tell the altitude of the aircraft when it is above approximately 10 feet, and an independent, more accurate altimeter that will be used for remote landing to tell the pilot the altitude close to the ground more precisely to avoid landing too hard.
In order for the pilot to be able to pilot the aircraft in situations other than line of sight, a camera (Item 1-4) is used to give the pilot a first person forward view. This helps the pilot fly at far distances when view of the plane is obstructed. The range of the camera transmitter (Item 1-7) is approximately a mile, so in order to fly using the camera, the plane must be no more than a mile away. For better transmission, the plane shouldn’t be more than ¾ of a mile away from the receiver (Item 1-8).
The telemetry transmitter (Item 1-5) used by this project will sense the wing positions as well as take data from the altimeter (Item 1-3) and gyroscope (Item 1-2). Then the transmitter will transmit the data to the receiver (Item 1-6) located on the ground for analysis and display on the computer. The telemetry device also contains the barometric altimeter as well as four sensors that will be used to determine the orientation of the wings, either vertical or horizontal, by measuring the position of the servos connected to each wing. The receiver for the telemetry signal has a USB interface to allow for easy connection to the computer.
Output of Control Responses to Transmitter
A programmable potentiometer will be used to interface with the transmitters being used. Since the transmitters are standard aircraft remote control radios, they normally use physical potentiometers controlled by the pilot for their inputs; in this case, they will receive their input from a programmable potentiometer controlled by the computer instead (Item 2-4).
Software Deliverables
The following section presents a comprehensive list of all software deliverables within the project. This includes control software and telemetry display software as well as user input and mathematical interpretation of user input.
Table 2: Software Deliverables
Item / Software / Brief Description2-1 / Control Input / Captures the inputs from the USB joystick device
2-2 / Control Variables / Saves inputs to one set of variables and the outputs to a distinct set of variables
2-3 / Control Math / Uses control functions to translate the inputs into outputs
2-4 / Control Output / Writes the output values to the programmable potentiometer
2-5 / Telemetry Data In / Capture the data input from the telemetry package
2-6 / Telemetry Video / Displays the video feed from the onboard camera to the pilot
2-7 / Telemetry Short Range Altitude / Displays the short range altitude to the pilot in a range between 0 and 12 feet
2-8 / Telemetry Long Range Altitude / Displays the long range altitude to the pilot in a range between 0 and at least 100 feet
2-9 / Telemetry Wing Tilt / Displays the current wing tilt setting to the pilot as an angle graph
2-10 / Telemetry Airspeed / Displays the current airspeed to the pilot as a graph
2-11 / Telemetry Positional Calculation / Uses the rate data from the gyroscope to calculate the 3D position of the aircraft
2-12 / Telemetry Artificial Horizon / Displays 3D positional information to the pilot in the form of an artificial horizon
2-13 / Telemetry Refresh / The telemetry data must be updated and re-displayed for real time operation
Display of Telemetry Data
A custom software suite is required to display relevant flight data to the pilot. Much of the internal structure of the software is being provided by Eagle Tree Systems, the company that produces the telemetry package. The remaining tasks in software design will be to use and manipulate the example code in order to fulfill the specifications. The telemetry data and video display will run on a generic Windows laptop; therefore storage, memory and processing power are not issues.