Team Vision for System Level Design Phase

The System Level Design phase focused primarily on the generation of design concepts and the solidification of high-level implementation details of those concepts. The work done in this phase forms a bridge between understanding the problem at hand and the design of a solution for that problem.  Beyond Concept Selection and high-level architecture design modelling, feasibility analysis was performed on both the concepts and the problem at hand.  The Problem Definition phase opened more questions than it answered by the time it was finished, and so answers to those questions of scope and others were explored.

Systems Level Design Goals:

  1. Develop multiple design concepts based on the CRs and ERs and the various tools provided in the systems level design phase modules.
    1. Subtract and operate
    2. Function Trees
    3. Transformation Diagrams
  2. Analyze the feasibility of the developed concepts.
  3. Develop selection criteria based on CRs and ERs to help filter through the concepts.
    1. Construct a Pugh chart based on the selection criteria
  4. Identify potential rules, regulations and safety standards that need to be considered in future development and testing.
  5. Develop high level systems level flow charts to describe basic connections and concepts.

Updated Use Cases

The use cases which were created during the Problem Definition phase were concerned with operational modes and failure modes. In this phase, the team found that those use cases did not sufficiently constrain and define the problem at hand.  In an effort to avoid feature creep, three use cases which will be tested against were selected by the customer and developed by the team.

Flooded Area

In the use case of flooded areas, the drone is expected to operate in flood like conditions while gathering data in mostly suburban areas.

Night Time Search Operations

Night time  operation will have to adjust for the lack of light and the fact that the visible light camera will no longer be as effective.

Lost Hiker (Daytime)

The lost hiker scenario will assume mostly wooded areas and lots of foliage, making direct line of sigh detection difficult.

Functional Decomposition

Subtract and Operate




StructuralProvides Lift

AileronsFeedbackProvides mechanical heading control

PropTransmissionCreates thrust

MotorTransmissionProvides rotational energy to prop

BatteryPowerMain power source


StructuralProvides stiffnessProvides strengthProtects electronics, other in event of crash
SkinStructuralProvides optimal aerodynamicsProtects sensitive electronics inside from weather, wind, etc.
MicrocontrollerControlProvides computerized controlControls failure operationProvides control system stabilization
Microcontroller mountStructuralKeeps microcontroller coolProtects microcontoller from turbulence, sudden impact
Motor mountStructuralKeeps motor coolMinimizes vibrations to rest of frame
Thermal imaging cameraInformationProvides sensor data for person locationProvides navigational aide
Camera GimbalStructuralMinimizes vibration to cameraHolds camera in optimal data collection positionprotects camera from sudden impact
Control Surface ServosControlMoves Ailerons/Elevators

Wing Tips/StabilizersStructuralGuides planeReduces severity of wing inconsistencies
RF RX/TXControl/TransmissionProvides telemetry to pilotProvides emergency controlProvides emergency data dump
CasingStructuralProtects inner mechanicsDesigned to be aerodynamicHolds things together for flight
Thermal SensorInformationSense body heat

Memory UnitInformationStores the flight dataHold recorded sensor dataKeeps location of people found
GPSInformationKeeps track of drone locationRecords location of person found
CameraInformationTakes picture of scenery and area belowUsed to gather information for person detection
Remote ControlControlControl code to the drone during non-autonomous stageAllows for communication between drone and pilot
AntennaeTransmissionAllows for information transfer

Each part listed in the subtract and operate function falls under four categories: structural, control, transmission, and information. Information includes parts that are mainly utilized for data storage and processing. Structural components include the parts that make up the physical frame the drone, such as drone casing and camera gimbal. Lastly, the control parts deal with maneuvering the drone and flight control.

Function Tree

Transformation Diagram

Safety Standards

ASTM F2909-19Standard to address minimum requirements for determining if a drone is continually airworthy
ASTM F2910-14Standard Specifications for designing and building small unmanned aerial systems
ASTM F3002-14aStandard Specifications for designing control systems for small unmanned aerial systems
ASTM F3366Standard Specification for General Maintenance Manual
ASTM 3201-16Standard Specification for ensuring dependability of software used on UAS
NFPA 2400

Small UAS for Public Safety

FCC Part 1515.247.a3 RF on the 5.8GHz band
FCC Part 1515.245 RF on the 2.4GHz band
FAA 107.12Requirement for a remote pilot certificate with a small UAS rating
FAA 107.29Daylight Operation. No persons may operate a small unmanned aircraft system during night.
FAA 107.51

Operating Limitations.

The groundspeed of a UAS may not exceed 87 knots (100mph).

The altitude of the UAS cannot be higher than 400 feet above ground level (unless there are structures...)

FAA 107UAVs should weight less than 55 lbs
FAA 107Visual line of sight must always be maintained with pilot and drone

Concept Development


Drone Type Analysis

  • Fixed wing drones and drones that are capable of switching are able to fly above 40 minutes at various price ranges.
  • Small increases in flight time on a rotary drone costs significantly more money.

  • Fixed wing drones are able to achieve a significantly greater flight time with lower battery capacity compared to rotary drones.
  • It can be observed that rotary drones struggle to have a flight time above 40 minutes even for various battery capacities.
  • SUI Endurance with a battery capacity of 9000 mAh only has a flight time of 40 minutes (and costs about $13500).
  • No such plateau is observed for fixed-wing aircraft.
  • There is a higher cost per minute to fly rotary drones than fixed-wing drones.

                                                                                                                                Flight Time Analysis

  • It becomes extremely expensive to achieve long flight time.
  • Price increases significantly as battery capacity increases.

Morphological Chart

Concept Selection

Concept Component1 - Flex2 - Fixed3 - Rotary
PropulsionOpen PropEDFOpen Prop
Take-offVTOLSpring-Assisted LaunchVTOL
Imaging/SensingVisible LightVisible LightVisible Light
Sensor MountingGimbalUnderneathGimbal
Body TypeVTOL FixedFixedRotary (3-4)
Crash ProtectionParachuteParachuteParachute
SteeringElevonsElevonsThrust Vectoring
Data StorageP2P RadioP2P RadioP2P Radio
Indicate Victim LocationDon'tDon'tDon't
Sensors for PeopleVisible LightVisible LightVisible Light
ConstructionFoamAluminumCarbon Fiber/Wood

Pugh Chart

Microcontroller Selection

Benchmarking for Microcontrollers was done by comparing several different types of microcontrollers together. For ease of comparison, a color coordinated chart was created to compare the different features and decide which microcontroller had the most desired features. According to preliminary results, the MK64F12 stood out as the most desirable as it had the largest ROM, RAM, and number of UARTs. The only draw back with this microcontroller was its price point in comparison to the other devices; however, due to previous circumstances the team has access to several of these microcontrollers, making the price point negligible.

Motor Selection

Selection CriteriaDescription
Operating VoltageVoltage at which the motor operates.

Lighter motors yield a faster change in speed; Heavier motors yield a slower change in speed.

Efficiency (g/W)

Thrust per power. The motor must be efficient throughout the range of operation.

PowerBatteries must be able to handle the power requirements of the motor.

Rotational force about an axis.

Effects the time it takes the propeller to reach a desired speed.

Higher torque motors are easier to tune.

Kv Rating

The negative of the torque constant.

High Kv motors tend to be more efficient at high RPMS but at the expense of torque.

High Kv motors tend to require more current than lower Kv motors to produce a certain torque.

Motor selection criteria is highly dependent on the selected concept. The following all affect the operation of the motors:

  • Frame Size
  • Propeller Size
  • Stator Size

As a result, no comparisons will be made at this stage.

Battery Selection

Battery Selection is highly dependent on concept selection due to the current draw requirements of the different models.  The "C rating" of a battery is the main determinant of the battery's current draw capacity, and consequently, batteries with higher C rating cost more money.  Once concept selection is completed and finalized, we will select appropriate batteries.  Some of the criteria we are considering are:

  • Series cell count
  • Parallel cell count
  • C rating
  • Capacity

Updated Risk Management Plan

RiskDescriptionRisk Type






(L x S)

Action(s) Taken
OverbudgetBudget is limited - no funding outside of team members and RITResource3515Avoid
FabricationMachine shop/Construct tools could be busy, or available building resources could be limitedTime339As soon as a preliminary design is settled upon, start to source materials and fabricate parts as they become finalized, not once all parts are finalized
Software (telemetry)Telemetry is difficult, and difficult to debug.  Significant technical challenge.Technical339Start early, plan ahead for this challenge, since it will be necessary during testing.
InjurySomeone could be hit by the drone, or cut by the spinning propSafety2510Have a designated drone spotter when testing, mark dangerous area on drone with labels, have a testing plan with steps clearly outlined to ensure personnel safety, only test drone in areas away from residential areas
Drone ProtectionEffective crash mitigation tech may be expensive or technically difficult to implement, affect CR's and putting drone safety at riskResource4312Choose a concept which has crash protection built in.  Ensure pilots are trained before flying the real aircraft.
Efficient WiringSmall problems in wiring and electrical design can become troublesome quickly.Technical339Consider current flows, do initial testing.  Overbuild subsystems likely to cause problems (engine power subsystem, for example).
TestingA quick, accurate, and safe way to test drones is critical given that we cannot test on campusTechnical/Time5420Choose a concept which we are capable of testing.
Flight TimeThe drone should be able to maintain flight long enough to test fully and not worry about sudden loss of power mid-flightTechnical248Choose a concept for which we can optimize power consumption and therefore flight time.
Limited Number of DronesOnly so many testing drones can be constructed with budget constraintsResource339We will only be able to build one drone, but we have two indoor aircraft that may be used as trainers.
Loss of Team MemberReduced work capacity due to missing/absent team members.Resource5


5Mitigation plan is to reduce our dependency on custom mechanical parts. (Ben is leaving)
Customer RedirectionA new customer is added, thus changing CRsTime144Mitigated.  At this point it is not feasible for the team to take on a new customer.
Customer AbsenceNo official outside customer is identified, leaving us with speculated CRs and little expert knowledgeInformation5210We have been continuing our design validation  and analysis techniques.
Extended WinterInclement conditions make flight testing difficultTime248Find resources where we can reserve indoor flying space, even if small.
Unexpected RoadblockUnforeseen technical hurdle, miscommunication or serious bug not found in testingTechnical5315Plan project.  Break large tasks into smaller ones until they can not be broken down further. Ensure communications are clear and quick.
Team CommunicationWealth of information spread across platforms and people could create discrepancies in planningPersonal515Communicate in advance of personnel absences, after every meeting post in group chat what assignments were and the expected due dates so there is accountability

Updated Engineering Requirements

Systems Architecture

Hardware Connections

Data Transmission

Power Subsystem

Software Flow

Phase 3 Preview

Gantt Chart

Team goals

For the next phase, we would firstly like to complete all necessary research including material and component selection, testing facilities and other subsystem research. Next, we would like to come to create at least a proof of concept of a frame designed as well as some prototyping data using FEA in ANSYS (mechanical engineers). As a team we need to come to a decision on electronics on board, select them and come up with a general layout of how they will be implemented (electrical and mechanical engineers). We would also try and order some parts so we can physically see any limitations our frame might have. Finally, we would like the computer engineers to start developing a plan on how this will be coded. The way we strive to achieve these goals are listed below.

Individual Goals


  • Speak with Dr. Kaputa about this UAV project, specifically about pattern recognition and possible testing options.
  • Work with the team to determine exactly what sensors will be used.
  • Talk to Gordon field house reps about possibly using the field house facilities for testing.
  • Work with Piers, Andy and Sabrina to come to a consensus on which microcontroller to use.
  • Determine which power supply to use, i.e. either two power supplies for motors and sensors, controller or modular power supply with multiple voltage outputs.
  • Research and understand power management schemes.


  • Look into sponsorships for sensors.
  • Assist with any DevOps infrastructure.
  • Research controls for both fixed wing and rotary drones.
  • Research PhysX for simulations.
  • Research design of debug infrastructure for embedded devices.
  • Finalize the selection of motors.


  • Assist with test/prototyping setup for software.
  • Narrow down budgets for each component needed for the drone.
    • Include budget plan for prototype components.
  • Assist with simulation options and which options are most applicable in terms of realistic flight mechanics and physics while still maintaining feasibility for quick testing.
  • Have a concrete selection for which microcontroller to use.
  • Work with Piers and Andy to decide how many sensors can be feasibly purchased within budget.
  • Figure out how much data needs to be stored for the duration of one flight (assuming that most processing will be done off board).


  • Design Electronics Holder.
  • Research and Design Emergency Release mechanism.
  • Research build materials.
  • Work with team to prototype different drone frames.
    • Keep in mind electric components and sensor wiring needed.
  • Prep drawings for next design review.
  • Learn ANSYS for FEA analysis.


  • Design Frame (SolidWorks).
  • Use cardboard, wood, and 3D printing to prototype early release connectors.
  • Use cardboard, wood, and 3D printing to prototype early frames for structural analysis.
  • Work with team to prototype different drone frames.
  • Prep drawings for next design review.
  • Learn ANSYS for FEA analysis.


  • Produce a good test-prototyping timeline.  In summary, what supporting designs do we want to have ready to run, and by when?  We will need to get going on some of this pretty soon in order to really understand our concepts.
  • Reach out to nearby organizations for sponsorship. While at this point we are not interested in gaining an external customer, finding some interested persons who also have funding would be nice.
  • Investigate options for simulation.  There are several modifications to the popular game Kerbal Space Program which add realistic flight mechanics and physics.  Qualities of real engines and wings can be added to the game with relative ease, which might make it worth looking at.  ANSYS is likely a better overall solution, but it may be faster to set up this game in the short term.
  • Explore places we can fly outdoors.  Martin Road Park, North Hampton Park come to mind.
  • Explore feasibility of different sensor options.  Questions include "how much power draw?", "how far can it see?", "how much onboard processing is needed?", and others.
  • Work with Ben and Mutahir on frame prototypes, specifically motor mounting options and propellers.  I think I have a CAD model of the standard motor mount for outrunners somewhere.
  • Look into gimbal options. These are traditionally quite expensive and involve a lot of motors or servos, as well as several PID feedback loops and complex vibration sensing.
  • Work on ensuring everyone is on task and not overwhelmed.  The weeks are getting shorter but the work is getting longer, so some facilitation will be necessary to minimize team-wide burnout and frustration.
  • Finalize battery selection criteria, and select the battery or batteries that we intend to use.
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