Team USAS CDR. Tom Bateman Barry Blakeley Adam Dean Jake Hanft Mike Sheek. Team USAS CDR 1

Transcription

1 Team USAS CDR Tom Bateman Barry Blakeley Adam Dean Jake Hanft Mike Sheek Team USAS CDR 1

2 Presentation Overview Status of RFA s System Architecture Mechanical Design Elements Electrical Design Elements Software Design Elements Verification and Test Plans Project Management Team USAS CDR 2

3 Status of RFA s from PDR RFA Rationale Response Include a goal of a testbed with a validated model Provide additional capabilites of already existing COTS UAV stability systems Added the requirement of a simulated model of our system for test predictions and comparisons Revisit the dynamic range for data storage. Make sure the verification needs are met with low dynamic range 8 bytes = 1/256 MSB resolution. (Dynamics Usually > Bits) Made necessary adjustments for data storage needs Team USAS CDR 3

4 System Architecture Adam Dean Team USAS CDR 4

5 System Architecture Overview of Objectives USAS Goal Provide artificial pitch-rate damping for small UAV with the use of a microcontroller interfaced with a sensor package and the pitch control servo. The system will provide capability similar to existing stabilization gyro packages, with additional features and flexibility, such as in-flight gain control Team USAS CDR 5

6 System Architecture Overview of Requirements SAS Requirement Quantity Reason Artificial Pitch Axis Damping equivalent to 10% SM Primary Goal Inflight Command Override Return C.G. to full frontal position/ Disable Safety SAS Limited Control Authority ~ 10% Safety System Response Time ~ 10ms Airplane Pitch Bandwidth ~ 10Hz Automatic System Recovery Time << 250ms Pilot Reaction Time Data Sampling Rate >> 50 Hz Servo PRF Data Resolution >= 8 bit Max Servo Resolution Team USAS CDR 6

7 System Architecture Overview of Requirements Test Bed Aircraft Requirements changes since PDR are highlighted Requirement Quantity Reason Size (Generic) 0.60 in^3 Low cost/performance Wing Loading oz/ft^2 Flying qualities / Stall Speed TOGW 15 lb Max Flying qualities / Stall Speed / Payload Wingspan 72 in Size / Wing Loading Propulsion Electric Reduced noise & vibration, clean Payload Capacity (Electronics) 2.5 lb / 90 in^3 (PDR lb / 206 in^3) Electronics Payload Moveable CG +10% - 0% SM Testing Team USAS CDR 7

8 System Architecture Overview of Requirements Simulations Requirements changed since PDR are highlighted Requirement Reason Flight Dynamics Model Simulate the expected system response for test predictions and comparison to actual system data Aid in the design of control algorithm Wing Structural Model Insure the performance capablities of the aircraft Control System Software Simulation Validation of control software functionality prior to flight Team USAS CDR 8

9 System Architecture System Design SAS SAS System Element Purpose Quantity Reason Rate Gyro Measures the pitch rate of the airplane deg/s Control system calculations and algorithms Accelerometer Measures the airplane acceleration in the pitch axis g Control system calculations and algorithms Pressure Transducer Measure dynamic pressure with pitot-static tube 0-1 psi Calculate airspeed - used in the control system s software Microchip PIC1854F CPU Data processing Data Storage Storage of the measured flight quantities, pilot input, and control system output in flight 275 kb Testing, verification and data analysis Pilot Signal Transmission Gives the proper flight commands to the flight control system Command override Controller Signal Transmission Controls the movement of the c.g. apparatus and in-flight gain of the SAS Reduced pilot workload Team USAS CDR 9

10 System Architecture System Design Test Bed Aircraft Aircraft Characteristics Design Engine Type Electric Size 0.60 in^3 Wing Span 84 in. Wing Loading 37 oz/ft^2 Airfoil Root -S4233, Tip -SD7062 Material Fiberglass Composite Total Weight 13.5 lb +/- 5% Payload Capacity Electronics 90 in^3 Batteries 40 in^3 Avionics 52 in^3 Total 177 in^3 Structure Fiberglass Composite Shell w/ Plywood Bulkheads Fuselage Integrated Aluminum Backbone Modularity Moveable C.G. Adjustable Tail Volume Integrated Backbone Team USAS CDR 10

11 Team USAS CDR 11

12 System Architecture System Design C.G. Apparatus Parameter Relevant Specification Objective Notes Moveable Weight 1.08 lbs Attain +10% - 0% SM SM is linearly related to slew of Balance Weight Total Longitudinal Movement 11.5 in Attain +10% - 0% SM Use gear rack and pinion design to move apparatus Control Servo Futaba Sail-Winch Servo Torque oz-in Speed rad/s Max Revolutions - 6 Torque / Speed Gear wheel radius -.75 Needed revolutions Max Travel Time s Slide Mechanism 3/8 Diameter radial bearings Prevent apparatus from sticking Bearings will slide in grooves cut in backbone Position Measurement Servo Feedback Measurement Data Acquisition Eliminate need for external sensor Team USAS CDR 12

13 System Architecture Verification Analysis SAS Simulink model of simulated dynamic response Test Bed Aircraft Flying qualities determination spreadsheet C.G. location/manipulation stability spreadsheet Static wing loading simulation, test, and analysis Technology Demonstrator Aircraft (TDA) flight Team USAS CDR 13

14 Mechanical Design Elements Mike Sheek / Tom Bateman Team USAS CDR 14

15 Mechanical Design Outline Drawing Tree Stability Analysis Stability Configurations CG Apparatus Adjustable Tailboom Fuselage Design Wing Design Weight Analysis Team USAS CDR 15

16 Mechanical Design Elements Drawing Tree Team USAS CDR 16

17 UAV Stability Configurations Difference in positions of horizontal stabilizer with reference to wing root c/4 C r / 4 C rtail / 4 c Total distance traveled by moveable CG apparatus M_CG loc Forward Tail loc Aft Static Margin 10.0% CG aft of cr/4 (in) 2.49 Moveable CG wgt = 1.08 lb Aft Aft 0.0% 3.41 Forward Forward 5.7% 2.26 Aft Forward -4.3% 3.17 Team USAS CDR 17

18 CG Control Apparatus Backbone Roller Track Shuttle Assembly Limit Stop Rack Gear Ball Bearing Rollers Drive Servo Servo Battery Team USAS CDR 18

19 CG Control Apparatus (cont) Bearing Shaft Spur Gear Drive Servo Spacer Ball Bearing Roller Shuttle Frame Team USAS CDR 19

20 Adjustable Tailboom Stabilizer Vertical Fin Tailboom Backbone Rudder Servo Elevator Servo Tailboom Adapter Team USAS CDR 20

21 Fuselage Design Effectively integrate backbone concept to fuselage design Create non-structural fuselage shell with minimum weight Connect all components directly to backbone for structural support Lighten fuselage by ~20% from TDA Team USAS CDR 21

22 Nose Section Cutaway Electric Powerplant Control Linkage Main Battery 15x6 Propeller Backbone NWS Servo Nose gear Strut Nose gear Mount Team USAS CDR 22

23 Wing Design & Construction Team USAS CDR 23

24 Structural Design Normal Bending Moment Distribution M, lb-ft Spanw ise Station Distributed Load Approximated (test) Load Point Load at Tip Team USAS CDR 24

25 Wing Structural Load Test Digital pull scales Elastic bands Support structure Load straps Tip support Holding Jig Team USAS CDR 25

26 Wing Structural Load Test Wing Panel Under Fully Applied Load Team USAS CDR 26

27 Aileron Servo & Pitot-Static Probe Access Pitot-Static Probe Servo Bay Control Linkage Aileron Servo Access Panel / Servo Mount Team USAS CDR 27

28 Test Bed Weight Analysis Aircraft Subsystem Weight (kg) Weight (lb) Weight % Power plant Batteries % Wing % Fuselage / Backbone % Electric Power plant % Electronics % Moveable CG Apparatus % Tail % Landing Gears % Total % Team USAS CDR 28

29 Electrical Design Elements Jake Hanft Team USAS CDR 29

30 Electrical Design Elements Block Diagrams Microcontroller PIC18F458 Rate Gyro Pressure Transducer Electrical Schematics Chassis Power Analysis QuikFlash Board Data Acquisition Accelerometer Team USAS CDR 30

31 Controller Board Block Diagram PROCESS INTERRUPT PITCH DYNAMIC Z-AXIS DATA SWITCH RATE PRESSURE ACCELERATION PITCH COMMAND CG CONTROL GAIN CONTROL PWMD PWMD PWMD 0/1 A/D A/D A/D 0/1 A/D A/D A/D MICROCONTROLLER VDD 0/1 PWM A/D PWM A/D 0101 PITCH FEEDBACK CG CONTROL FEEDBACK PITCH COMMAND CG COMMAND COMMAND OVERRIDE V REF REG DATA ACQUISITION (EXTERNAL EEPROM (512k)) Legend POWER 6-9 VDC COMMANDS SENSORS V REF FEEDBACK OUTPUTS Team USAS CDR 31

32 Command Override Process PWM (C/O Signal) LPF 0.1 or 0.2 V + COMPARATOR - Digital Output (1/0) I/O Pin Vref (0.15 V) Team USAS CDR 32

33 PWM Decoder Process PWM + - LPF One-Shot Control Voltage Team USAS CDR 33

34 Sensor Board Block Diagram Rate LPF Out1 Filter, SF, Zero g offset VDC Accel LPF Out2 Pressure LPF Out3 Team USAS CDR 34

35 SAS Schematic Team USAS CDR 35

36 Sensor Board Schematics Team USAS CDR 36

37 Power Analysis Power Breakdown Standard 9 Volt battery ~ 200mAh 1/2 hour of flight time Bench testing required for regulator operation Component Microcontroller (PIC18F458) Rate Gyro (ADXRS150) Accelerometer (ADXL 150) Pressure Transducer (SDX Series) Voltage Regulator (LM340T-5.0) Operating Voltage Range (V) Current Draw (ma) to (8.0 Max) 4 to (3.0 Max) < 20 < Vin 20 8 Total 5 <300 Team USAS CDR 37

38 Data Acquisition Specification Parameter goal Reason Notes Sampling Rate > 50 Hz Servo PRF Resolution 10 bit ADC Resolution Minimum Channels 8 Signals to be monitored 1 Pilot Elevator Command Calculated Output Command 2 Pitch Rate CH No. 3 4 Control System Output Airspeed 5 CG Position 6 Gain Control 7 Pitch Feedback 8 CG Control Feedback Minimum Sampling Time 300s 1/2 Flight Duration Estimated endurance 10 min Minimum Storage Capacity 275kB 50Hz x 9ch x 300s x 2 byte/data point Team USAS CDR 38

39 System Noise Analysis Possible Sources of Noise Component System Input Plan of Action May have khz of noise during flight Propeller Engine Brushes 10,000 rpm 10 x rpm (100,000) Test system with engine on and off Vibrational Noise Pressure Noise ~10 khz ~10 khz Filter accordingly Team USAS CDR 39

40 Software Design Elements Tom Bateman Team USAS CDR 40

41 Control Process Flow Start (power on) Z-axis acceleration Dynamic pressure Pitch rate A/D A/D A/D Initialize variables Watchdog/ Brownout Bypass CG control Estimate commanded pitch rate 0/1 Data switch Pilot command Gain control CG control PWM PWM PWM Read sensor inputs Read command inputs Timing Loop Compute PR error Apply control gain Primary Control Algorithm Command override 0/1 Read feedback inputs Compute elevator deflection Elevator servo CG Servo Data switch A/D A/D 0/1 Command Override? Y Bypass pitch control N Apply SAS Authority Limiting Output elevator control signal PWM Pitch command CG command PWM Command CG to full forward 0101 Output data External acquisition EEPROM Team USAS CDR 41

42 Primary Control Algorithm Pseudo Code STEP DESC I/O IN / OUT TYPE QTY UNITS 1 Read pitch rate RG IN A/D bin 2 Read z acceleration ACC IN A/D bin 3 Read dynamic pressure PT IN A/D bin 4 Read PC servo feedback signal FB_P IN A/D bin 5 Read CG servo feedback signal FB_CG IN A/D bin 6 Read PC pilot command CMD_P IN A/D bin 7 Read CG position command CMD_CG IN A/D bin 8 Read gain control CMD_G IN A/D bin 9 Read command override state CMD_CO IN DIG 0, 1 bool 10 Read data acquisition state CMD_DA IN DIG 0, 1 bool 11 Scale pitch rate deg/s 12 Scale z acceleration g 13 Convert dynamic pressure to indicated airspeed ft/s 14 Convert PC feedback signal to position deg 15 Convert CG feedback to longitudinal position in 16 Convert pilot command to commanded position deg 17 Convert CG command to commanded position in 18 Convert gain control to numerical gain TBD Team USAS CDR 42

43 Primary Control Algorithm Pseudo Code STEP PROCESS NOTES 1 Compute estimated alpha az*2*w/(g*rho*v^2*a) = alpha 2 Compute SAS commanded elevator deflection scale factor 3 Estimate tail downwash lookup table or scale factor and alpha 4 Compute tail moment contribution flight mechanics 5 Compute wing moment contribution flight mechanics 6 Compute angular acceleration alpha_dot_dot = M / I 7 Integrate to find pitch rate Euler integration: d_alpha dot = alpha_dot_dot * dt 8 Compare computed PR to measured PR 9 Apply proportional gain to PR error 10 Differentiate measured pitch rate to find angular acceleration dpr / dt 11 Compare measured AA to computed AA 12 Apply derivative gain to AA error 13 Compute elevator deflection error 14 Apply elevator correction to pilot command 15 Output elevator command signal Team USAS CDR 43

44 Testing of Control Algorithm - Simulink Team USAS CDR 44

45 Simulink Model (Detail) Team USAS CDR 45

46 System Dynamic Response System Off Step Input System On System Off Turbulence System On Team USAS CDR 46

47 Simulink Model Final model will include: Random processes simulating system noise Individual sensor inputs Simulated pilot input through random process implementation Detailed control algorithm based off of aircraft dynamics and control models Team USAS CDR 47

48 Additional Testing of Software Complete hardware mock set-up Initiate disturbances to fuselage and tail assembly Analyze data to see system response Team USAS CDR 48

49 SAS Latency Analysis Include analysis based off of processor speed and estimated number of commands Team USAS CDR 49

50 Integration Plan Tom Bateman Team USAS CDR 50

51 Unit Test Plan Major Task Description Primary Goal Deliverables Basic Microcontroller (MC) Operations Perform basic I/O operations on the PIC18F4xx, including digital I/O, A/D input, PWM output and memory writes Familiarization Test and verify MC implementation of digital I/O, ADC, and PWM capabilities Advanced MC operations Perform PWM servo feedback control tests PWM input and output, ADC input, R/C Receiver interfacing, performance analysis Operate R/C controls with MC in the loop Sensors and signal conditioning Perform bench tests of sensors, determine signal conditioning requirements Familiarization, signal conditioning design Test and verify sensor outputs, signal ranges, SNR's, and signal conditioning hardware Advanced sensor operations Calibrate and test sensors in field environment, using PIC interface Unit test of sensors, flight certification Test and verify operation of MC and sensor package in flight Programming Write individual signal processing and control blocks Code development Test and verify operation of real time control software modules Support Operations Develop critical subsystems, such as command override processing, power conditioning, backup systems Electronic hardware design Develop, test, and verify operation of all necessary electronic hardware support elements Manufacturing Quality Control Implement quality assurance on critical airframe components Flight safety, mission performance Test and verification data on critical components, such as wing Evaluation Flight Testing Shakedown flight testing of airframe Pilot familiarization, aircraft trim adjustments, evaluation of flying qualities Qualitative flight test analysis Specification Flight Testing Detailed flight test of airframe Establish baseline aircraft performance characteristics All aircraft performance parameters applicable to SAS verification testing Structured Research Build and test individual sensor subsystems in ASEN 4519 Resource management Perform measurements with primary sensors using MC Team USAS CDR 51

52 Verification and Test Plans Barry Blakeley Team USAS CDR 52

53 Verification and Test Plans Systems to verify UAV flying qualities SAS performance Alternative test Team USAS CDR 53

54 Verification of Flying Qualities Hypothesis UAV will qualify at Level 1 or Level 2 on a modified Cooper-Harper scale Pilot compensation not a factor for desired performance. Team USAS CDR 54

55 Verification of Flying Qualities Pilot Rating Scale Rating Aircraft Characteristics Excellent highly desirable Good negligible deficiencies Fair some mildly unpleasant deficiencies Minor but annoying deficiencies Moderately objectionable deficiencies Very objectionable but tolerable deficiencies Major deficiencies Major deficiencies Major deficiencies Major deficiencies Demands on the Pilot Pilot compensation not a factor for desired performance Pilot compensation not a factor for desired performance Minimum pilot compensation required for desired performance Desired performance requires moderate pilot compensation Adequate performance requires considerable pilot compensation Adequate performance requires extensive pilot compensation Adequate performance not attainable with maximum tolerable pilot compensation. Controllability not in question Considerable pilot compensation is required for control Intense pilot compensation is required to retain control Control will be lost during some portion of required operation Team USAS CDR 55

56 Verification of Flying Qualities (continued) Measured Response Pilot compensation required to maintain attitude Controlled Experimental Variables Prefer wind speed < 5 mph Prefer ambient temperature 50ºF - 70ºF Pilot experience Wind speed < 25 mph Ambient temperature 35ºF Team USAS CDR 56

57 Verification of Flying Qualities (continued) Sensors Pilot assessment of aircraft flying qualities Team USAS CDR 57

58 Verification of Flying Qualities (continued) Test table Trial Maximum Throttle Setting (%) Maneuvers Control-surface check (pre-flight) Left and right turns Left and right aileron rolls Climb without stall Left and right turns Left and right aileron rolls Abrupt upward pitch Left and right turns Left and right aileron rolls Abrupt upward pitch Team USAS CDR 58

59 Verification of Flying Qualities (continued) Procedure Radio and servo check Conduct flying tests according to the test table The pilot will rate the UAV flying qualities Measurement Error Estimate N/A Analytical Prediction of Measured Responses N/A Team USAS CDR 59

60 Verification of Flying Qualities (continued) Plot and Analysis N/A Applicable Drawing USAS-T-01 Test-Bed Aircraft Team USAS CDR 60

61 Verification and Test Plans Systems to verify UAV flying qualities SAS performance Alternative test Team USAS CDR 61

62 Verification of Stability Augmentation Hypothesis Stability Augmentation System will provide pitch-rate damping equivalent to 10% static margin (SM) Measured Response Pitch-rate damping time constant Pitch rate oscillatory frequency Team USAS CDR 62

63 Verification of Stability Augmentation (continued) Controlled Experimental Variables Throttle setting Static margin Stretch goal: Vary tail volume to test dynamic stability Sensors Pressure transducer with pitot-static tube Rate gyro Accelerometer Team USAS CDR 63

64 Verification of Stability Augmentation (continued) Test Matrix SM (%) Throttle (%) Team USAS CDR 64

65 Verification of Stability Augmentation (continued) Procedure Fly in stable configuration with 50% throttle Pilot pitch command Enable augmentation system Fly in stable configuration with 50% throttle Pilot pitch command Fly in stable configuration with 75% throttle Pilot pitch command Reduce SM to 7.5% with 50% throttle Pilot pitch command Keep SM at 7.5% with 75% throttle Pilot pitch command Continue according to test matrix Team USAS CDR 65

66 Verification of Stability Augmentation (continued) Measurement Error Estimate ±1% Analytical Prediction of Measured Responses Simulink model Team USAS CDR 66

67 Verification of Stability Augmentation (continued) Plots and Analysis Damping vs. throttle Damping vs. SM Applicable drawing N/A Team USAS CDR 67

68 Verification and Test Plans Systems to verify UAV flying qualities SAS performance Alternative test Team USAS CDR 68

69 Alternative Test for Stability System Controlled Experimental Variable Static margin Test Table SM (%) Team USAS CDR 69

70 Alternative Test for Stability System (continued) Procedure Install fuselage and tail section in wind chamber Adjust SM according to test table Team USAS CDR 70

71 Alternative Test for Stability System (continued) Measurement Error Estimate ±1% Analytical prediction of Measure Responses Simulink model Team USAS CDR 71

72 Alternative Test for Stability System (continued) Plot and Analysis Damping vs. static margin Applicable drawing N/A Team USAS CDR 72

73 Project Management Plan Adam Dean Team USAS CDR 73

74 Organizational Responsibilities Task Lead Responsibility Program Manager Adam Dean Scheduling, Task Management, Project Progress Chief Financial Officer (CFO) Barry Blakeley Program Budget, Budget Projections, Budget Reports Website Maintanence Mike Sheek Website Maintenance/Updates Safety Engineer Tom Bateman Group and System Safety Control System Software Control System Hardware Moveable C.G. Apparatus Test-Bed Aircraft Flight Control/USAS Integration Projest Test and Evaluation Jake Hanft Jake Hanft Mike Sheek Tom Bateman Tom Bateman Barry Blakeley Development and functionality of the control system Functionality testing development, and integration of the control system hardware Design, Fabrication and Verification of the integrated movable C.G. apparatus Assessment of aerodynamic, and structural properties of the aricraft to determine flight characteristics and overall design Integration of the flight control system with the C.G. apparatus and the SAS Acquisitions of proper flight data to test the SAS and result evaluation and documentation Team USAS CDR 74

75 Project Organization Chart Chief Chief Financial Financial Officer Officer (CFO) (CFO) -Barry -Barry Blakeley- Blakeley- Safety Safety Engineer Engineer -Tom -Tom Bateman- Bateman- Project Project Manager Manager (PM) (PM) -Adam -Adam Dean- Dean- Website Website Maintenance Maintenance -Mike -Mike Sheek- Sheek- Control Control System System Software Software -Jake -Jake Hanft- Hanft- Movable Movable CG CG Apparatus Apparatus -Mike -Mike Sheek- Sheek- Control Control System System Hardware Hardware -Jake -Jake Hanft Hanft Test-Bed Test-Bed Aircraft Aircraft -Tom Bateman- -Tom Bateman- Flight Flight Control Control / / USAS USAS Integration Integration -Tom -Tom Bateman- Bateman- Project Project Test Test and and Evaluation Evaluation Team USAS CDR -Barry -Barry Blakeley- Blakeley- 75

76 Work Breakdown Structure 1.0 Program Management 2.0 System Engineering 3.0 Control System 4.0 Test-Bed Aircraft 6.0 C.G. Apparatus 7.0 Verification 8.0 Tests and Reporting 1.1 Scheduling 2.1System Integration 1.2 Budget Management (CFO) 1.3 Task Delegation and Organization 1.4 Weekly Time Sheet Collection 1.5 Website and Documentation 2.2 System Specifications 2.3 Design to Specs. Monitoring 3.1 Micro Controller 3.2 Control Theory 3.3 Power System 3.4 Software 3.5 Sensors (Rate Gyros, Accelerometer, etc.) 3.6 Data Acquisition 3.7 Integration 4.1Aero Dynamic Design 4.2 Structure 4.3 Fuselage Design 4.4 Backbone Design 4.5 Flight Controls 4.6 Tail/Tail- Boom Design 4.7 Fabrication 6.1 C.G. Apparatus Design 6.2 C.G. S/W 6.3 C.G. Manipulation Effects 7.1 SAS Simulation 7.2 Static Wing Loading Test 7.3 C.G. Control System Bench Test 7.4 TDA Flight Test 7.5 Test-Bed Aircraft Flight Test 7.6 C.G. Control System Flight Test 7.7 SAS Hardware Bench test 8.1 CDR 8.2 PDR 8.1 Fall Final Report 8.1 Spring Final Report 8.2 Test Plans 8.3 SAS Passive Inflight Test 8.2 SAS Active In-flight Test 8.3 Test analysis Team USAS CDR 76

77 Program Schedule Team USAS CDR 77

78 Program Schedule Team USAS CDR 78

79 Estimated Budget Breakdown Aircraft Stability System Movable CG Structure and hardware $ Sensors $ Position measurement $15.00 Radio and controls $ Software $0.00 Servo & battery $16.99 Propulsion and power source $ Microprocessor $0.00 Radio $ Miscellaneous $ Interface and Hardware $ Hardware $56.60 Data Acquisition $ Verification $ $2, $ $ Grand Total $3, PDR Estimate $3, Expenditures $1, Team USAS CDR 79

80 Specialized Facilities and Resources Wind Tunnel/Chamber Pitot Tube Calibration SAS Pre-Flight Test Aircraft Test Airspace Team USAS CDR 80

81 USAS First Flight Team USAS CDR 81