Spring Final Review. Collision Encounter Reduction for Unmanned Aerial Systems (CERUNAS) 29 April 2014

Transcription

1 Spring Final Review Collision Encounter Reduction for Unmanned Aerial (CERUNAS) 29 April 2014

2 Team Organization Critical Risks 2

3 Description Engineering Management Critical Risks 3

4 Critical Risks 4

5 Concept of Operations and Critical 2 Nonfunctional CPEs: - CPE 4: suas Components < 100g - CPE 6: Subsystems < $100 Full descriptions of CPEs can be found in Backup Low Speed, Propeller Driven A/C (100m/s ± 10%) in straight, level flight in uncontrolled airspace CPE 3: Initiate Avoidance CPE 5: Record Telemetry suas (< 2lbs, 10m/s ± 10%) CPE 2: Transmit MAC Data CPE 1: Determine Collision Potential Critical Risks Mgmt. 5

6 Levels of Success (LOS) Manned A/C Encounter Cone (MAEC) is a geometric region based on the velocities of the suas and MAC LOS 2: Ability of System to Trigger Removal of suas from MAEC LOS 3: Ability of System to Sense Presence and Trigger Removal of suas from MAEC LOS 1: Ability of System to sense presence in MAEC Critical Risks Mgmt. 6

7 Description Critical Risks 7

8 High Level HW Manned Aircraft Component suas Component Mechanical Components: Manned AC hardware enclosure (6x6in, 1in deep) Electrical Components: Manned AC PCB Xbee transmitter GPS receiver Battery Software: Manned AC flight software CG Mechanical components: suas hardware enclosure Software: suas code Electrical Components: Battery suas PCB Xbee receiver Critical Risks Mgmt. 8

9 Functional Block Diagram Critical Risks Mgmt. 9

10 Manned A/C Hardware PVC enclosure size: 5 x 6 Critical Risks Mgmt. 10

11 Manned A/C Electronics Layout HW Item Description Key Details Power System Power all componentry on PCB CERUNAS developed using COTS components Processor and Supporting System Location Verification System Communication System Printed Circuit Board (PCB) Main processor handling outgoing position data Support systems for PIC are CERUNAS-developed using COTS components Determine manned A/C position COTS Broadcast location of manned A/C COTS Backplane for all necessary systems Critical CERUNAS developed Voltage from battery: 7.4V Voltage after regulator: 5V Voltage to components: 3.3V ICSP Headers: flash program PIC Breakout Headers: general purpose I/O PIC comm. w/ XBee: 32 MHz (1 instr. cycle/4 clock cycles) LEDs: alive, GPS lock, transmission indicator GPS connects to PIC by asynch. serial at 9600 baud Pressure sensor: 24 bit conversion, absolute pressure XBee transmitter frequency: 900 MHz, 9600 bps XBee power draw: 260 mw at 3.3 V Size to fit componentry: 2 x 6 Verification and Risks Mgmt. 11

12 suas Hardware PCB cavity in DataHawk: 2 x 3 Critical Risks Mgmt. 12

13 suas Electronics Layout HW Item Description Printed Circuit and Board Objectives (PCB) Power System Power all componentry on PCB CERUNAS developed using COTS components Processor and Supporting System Communication System Main processor for unpacking manned A/C position data and triggering avoidance CERUNAS developed using COTS components Receive location of manned A/C COTS Voltage from battery: 7.4V Voltage after regulator: 5V Voltage to components: 3.3V Key Details ICSP Headers: flash program PIC Breakout Headers: one pin triggers avoidance via autopilot PIC comm. w/ XBee: 9600 bps PIC comm. w/ autopilot: bps LEDs: alive (PIC OS running), power XBee transmitter frequency: 900 MHz, 9600 bps XBee power draw: 29 mw at 3.3 V Backplane for Critical all necessary systems Size to fit componentry: 2 Verification x 3 and Risks CERUNAS developed Mgmt. 13

14 Manned A/C Flgiht Software Key : Initialize sensors, LEDs Check Battery Low Set Low Battery LED Set TX LED On Valid Calculation frequency: 10 Hz Check packet validity Send data to Xbee transmitter Nominal Set TX LED Off Invalid Packetize Data Read from GPS logger Read from pressure sensor Compute altitude Functionality Check Code Input/ Output Code Code for Core Flight SW Functionality Non-critical for proof of concept work if time permits Critical Risks Mgmt. 14

15 suas Flight Software Initialize Read suas GPS data from UART Read from Xbee Have valid data? Yes No Compute relative position vector Calculation frequency: 10 Hz Set CAS pin high Buffer 20 data points No In MAEC Yes Set CAS pin low No Recent detection Yes Write data to flash Key: Functionality Check Code Input/Output Code Code for Core Flight SW Functionality Requires Autopilot Modification Critical Risks Mgmt. 15

16 LOS 1 Ground 1a LOS 1 Ground 1b LOS 2 Flight 2 LOS 3 Flight 3 Critical Risks 16

17 CERUNAS Architecture Electronics: individual component MAC component suas component Populated PCB Hardware MAC enclosure MAC mounting suas component mounting MAC/ suas mass & C.G. Software MAC, suas Unit MAC, suas, MAC, suas Subsystem s HW Implementation & Compliance Subsystem Integrated System FAA Compliance Ease of user Implementation Level of Success 1 Sensing Subsystem Level of Success 2 Avoidance Subsystem Level of Success 3 Full System Functionality Factor of 1000 Reduction (SW Model, Postprocessing) s: 10 Reqts. Analyses: 17 Reqts. Inspections: 16 Reqts. Critical Risks Mgmt. 17

18 Level of Success 1 Sensing Subsystem Characterization, Range 1a Goals: Verify MAC Xbee can transmit required beamwidth from MAC mock cockpit (CPE 2) Verify suas Xbee can receive MAC transmissions at 2km (CPE 1) Verify CERUNAS sensing at 2km decoupled from avoidance (CPE 1) Required Output MAC packet validity indicators & heading suas packet validity indicators & GPS coordinates Physical measurements from range marking Critical Risks Mgmt. 18

19 Level of Success 1 Sensing Subsystem Characterization, MAEC Detection 1b Goals: Characterize accuracy of CERUNAS sensing subsystem in relation to geometric MAEC (CPE 1) Verify that CERUNAS sensing system has capability to sense presence in MAEC decoupled from avoidance (CPE 1) Required Output Detection times MAC packet validity, coordinates, and heading Pos/Neg MAEC encounter indicators Physical measurements from range marking Critical Risks Mgmt. 19

20 Level of Success 2 Avoidance Subsystem Characterization 2 Goals: Verify CERUNAS Avoidance capability decoupled from sensing capability (CPE 3) Verify that CERUNAS allows return to nominal flight after avoidance Characterize latency time required for switch-on of flight termination mode Characterize avoidance maneuver descent speed and expected duration Required Output FTM initiation/termination indicators Latency time between FTM command and execution FTM initiation altitude Critical Risks Mgmt. 20

21 Level of Success 3 Full System Functionality NOTE: LOS 3 testing not complete 3 Goals: Verify that CERUNAS can sense presence in MAEC and trigger avoidance Characterize expected avoidance times for full system. Gather data for verification of geometric definition of factor of 1000 reduction Required Output Times for maneuver start/stop MAC packet validity indicators, coordinates, & heading suas GPS coordinates saved to flash memory MAEC entry/exit indicators and FTM initiation/termination indicators Critical Risks Mgmt. 21

22 Modeling LOS 1 Ground 1 LOS 2 Flight Critical Risks 22

23 Modeling - Monte Carlo Simulation Comparison Parameter Initial Parameter Value Percent Varied [%] Parameter Range suas X Position 1000 m m suas Y Position 2000 m m suas Z Position m m suas Lateral Speed 10 m/s m/s suas Vertical Speed (Operational Mode) suas Vertical Speed (Flight Termination Mode) 3 m/s m/s 10 m/s m/s Latency to Initiate FTM 5 sec sec Latency to Exit FTM 5 sec sec Manned A/C Speed 100 m/s m/s Critical Risks 23

24 Modeling - Monte Carlo Simulation Comparison Collisions without CAS: 739/100,000 = 0.739% Factor of Reduction FOR = Collisions with CAS: 653/100,000=0.653% # Collisions without CAS # Collisions with CAS = = 1.13 Critical Risks Mgmt. 24

25 Modeling - Monte Carlo Simulation Comparison Critical Risks Mgmt. 25

26 Modeling - Monte Carlo Simulation Comparison Iteration MAEC Horizontal Size [m] MAEC Vertical Size [m] Number of Collisions (out of 100,000) Factor of Reduction (60+10%) (60+20%) (60+30%) (200+10%) 78 (60+30%) (200+20%) 78 (60+30%) (200+20%) 84 (60+40%) (200+20%) 90 (60+50%) MAEC horizontal and vertical size were increased to see impact on number of collisions (out of 100,000) (200+20%) 96 (60+60%) (200+20%) 102 (60+70%) (200+30%) 102 (60+70%) (200+40%) 102 (60+70%) (200+50%) 108 (60+80%) Critical Risks Mgmt. 26

27 Level of Success 1 Sensing Subsystem Characterization, Range Sensing Subsystem Characteristics: Distance Required 2km Achieved 4km Cross-sectional area: Required 120m x 415m Achieved 256 x 300m Location: Manned A/C - NCAR suas - CU East Campus Legend Packets Received Packets Not Received Transmission along lateral axis impeded by obstructions between South Campus testing site and NCAR Critical Risks Mgmt. 27

28 Level of Success 2 Flight 1 CONOPS CAS light triggers red on ground station 30 m At 70 m, suas board triggers FTM for 2 secs 40 m Launch Critical James takes manual RC control Autopilot takes control Data Hawk begins helix flight path Risks Mgmt. 28

29 Level of Success 2 Avoidance Subsystem Characterization Critical Risks Mgmt. 29

30 Level of Success 2 Avoidance Subsystem Characterization Repetition FTM Altitude (m) CAS Verification Latency Time (s) 1 90 No Yes Yes Yes Yes No Yes Yes Yes Yes No Yes Yes Yes Yes No - Avoidance Subsystem Characteristics: CAS successful 12/16 trials FTM Switch-on Latency: Expected 2.00s Average 3.08s FTM Initiation Altitude Expected 70.00m Average 71.25m Variable in test code times out after 4 repetitions, negating CAS, requires soft reset Critical Risks Mgmt. 30

31 Engineering Approach Engineering Issues Key Lessons Critical Risks 31

32 Engineering Approach Engineer Develop requirements hardware components Structures Engineer Electronics Engineer SW and Modeling Engineer Construct hardware components Manufacturing Engineer Develop PCB architecture Write code for interface between ma/c and suas Engineer and perform tests for requirements V&V verified and validated? Completion Key: Verification and Engineering Electronics & RF Equipment Physical Componentry Software and Modeling Critical Risks Mgmt. 32

33 Engineering Issues Connection between autopilot and CERUNAS Code parsed data in different ways Clock speed (57600 on autopilot) to change on CAS Interfacing SPI between pressure sensor and ma/c PIC Components foregone in interest of time: Interfacing between flash memory and PIC *Given lower priority have ground station telemetry Second Xbee receiver for packet integrity No time for battery power indicator Original requirements not specific enough for full design outline evolves in time with new information rewritten as appropriate Critical Risks Mgmt. 33

34 Key Lessons Aspect of Requirement Development System Interfaces Lesson - Keep project focused toward specific goals from customer, regulations, and mission success - must evolve during entire process - Do not underestimate difficulty of tracking connections between individual components and subsystems - Make sure to understand clocks, baud rates, transmission frequencies between existing technology and that developed for project - Ensure tests track to established requirements, or else make changes to existing architecture - Verification means you built the right thing; validation means you built the thing right. Critical Risks Mgmt. 34

35 Management Approach Budget Industry Cost Analysis Critical Risks 35

36 Management via a systems level consideration of team activities Activities monitored via inquiry, involvement, and status meetings Scheduling based on understanding of development progress and team inputs regarding process Adjusted based on progress and design changes Personnel tasking based on skillsets and critical path identification Ongoing documentation to ensure updated picture of system Critical Risks

37 Issue: Unexpected difficulty of integration with existing platform. Lesson: Account for additional time when integrating with existing systems Issue: Critical path delays due to SW incompletion and personnel transition Lesson: Ensure that critical path tasking is allocated sufficient support at an early date Issue: Insufficient time between completion of development and SWIT Lesson: Allocate additional buffer before test to allow for possibility of issues with SWIT Critical Risks

38 Data Hawk HW borrowed from customer PCB manufacture and remanufacture more expensive than anticipated Planned CDR Cost: $ Current Cost: $ Differences due to component pricing Critical Risks Mgmt. 38

39 Estimated Total Cost: $215,690 Estimated Total Hours: 3450 $51,562 $57,788 24% SW 27% Electronics 18% SEIT 18% PM 13% HW $37,850 $39,517 $28,977 Critical Risks Mgmt. 39

40 Backup Charts and Objectives Critical Requireme nts Risks Verificatio n and Plannin g 40

41 Critical CPE ID CPE Description Rationale CERUNAS must determine that the suas is in the encounter cone of a manned A/C based on reception of a signal provided by the manned A/C The manned A/C component of CERUNAS must be able to indicate either or both: The location and heading of the A/C Encounter cone boundaries for a suas CERUNAS must initiate any suas maneuvers required to move the suas outside of the manned aircraft encounter cone The suas elements of CERUNAS must have a mass of less than 100g Telemetry data for the suas must be collected and downlinked for any collision avoidance maneuvers CERUNAS transmitter and receiver Critical units must 6 each be mass producible and for less than $100 Objectives Schedule Manufacturing Status Requireme nts Indication of potential manned A/C-sUAS collisions Indication of potential manned A/C-sUAS collisions Avoidance of manned A/C-sUAS collisions Weight key to effective integration of CERUNAS with existing suas components Need to understand CAS effectiveness in real-world flight and to validate mission success - Cost-effective compared to cost of suas Verificatio - Cost-effective n and Plannin Risks for private pilot g Budget implementation 41

42 Sensing 1A System Level Requirement Number Requirement Text CAS.1 The CAS shall determine that the suas is in the encounter cone of a manned A/C based on reception of a signal provided by a manned A/C in order to reduce the volume of the MAEC by a factor of Critical Risks 42

43 Sensing 1B Functional Level System Level Requirement Number Requirement CAS.1 The CAS shall determine that the suas is in the encounter cone of a manned A/C based on reception of a signal provided by a manned A/C in order to reduce the volume of the MAEC by a factor of CAS.1.1 The initial volume of the MAEC for the manned A/C shall extend 2km in front of the manned A/C at an angle defined by the expected velocities for both the suas and manned A/C. Critical Risks 43

44 Avoidance Functional Level System Level Requirement Number CAS.3 Requirement The CAS shall complete any suas maneuvers required to move the suas outside of the MAEC while placing primary focus on avoidance and secondary focus on preservation of the suas. CAS suas post-maec recovery shall return control of suas flight operations to autopilot immediately after leaving MAEC. CAS CAS CAS suas autopilot shall be allowed full control of suas flight operations for remainder of mission following avoidance. Upon leaving MAEC, CERUNAS shall return control of suas to the installed autopilot. Recovery of suas shall return vehicle to original, preencounter flight regime. Critical Risks 44

45 Full Functionality Functional Level System Level Requirement Number CAS.1 Requirement The CAS shall determine that the suas is in the encounter cone of a manned A/C based on reception of a signal provided by a manned A/C in order to reduce the volume of the MAEC by a factor of CAS.2 CAS.3 The CAS shall complete any suas maneuvers required to move the suas outside of the MAEC while placing primary focus on avoidance and secondary focus on preservation of the suas. Telemetry data for the suas shall be collected and downlinked or saved for later download for any collision avoidance maneuvers. CAS suas post-maec recovery shall return control of suas flight operations to autopilot immediately after leaving MAEC. CAS suas autopilot shall be allowed full control of suas flight operations for remainder of mission following avoidance. CAS CAS CAS Critical Upon leaving MAEC, CERUNAS shall return control of suas to the installed autopilot. Recovery of suas shall return vehicle to original, preencounter flight regime. Added mass of CERUNAS to suas shall reduce suas flight time limitations based on power supply by no more than 10%. Risks 45

46 Miscellaneous Functional Level Level Requirement Number CAS.5 Requirement Telemetry data for the suas shall be collected and downlinked or saved for later download for any collision avoidance maneuvers. CAS.6 ing shall be carried out to allow for characterization and validation of CERUNAS system behaviors and to provide discrete data for post-processing analysis of system functionality. CAS.2.2 The manned A/C mountable element of the CAS shall not impact the functionality of any manned A/C HW or communications systems and shall have the ability to comply with applicable FAA regulations. CAS.4.1 CAS.4.2 The suas elements of the CAS shall have a mass of less than 100g. The suas elements of the CAS shall draw no more than 0.3 W from pre-existing UAV power. CAS Manned A/C mountable element of CAS shall have a redundant system to ensure packet integrity. CAS Manned A/C mountable element power supply shall operate as a single cell, with at least 5000 mah and 3.3 V. CAS Manned A/C mountable element power supply shall be rechargeable, with ~8 hr between charges. CAS Critical Manned A/C component of CAS shall be functional without impingement on pilot field of vision. Risks 46

47 Miscellaneous (cont.) Functional Level Requirement Number Requirement CAS Manned A/C component shall have the abliity to maintain stationary functioning location in the manned A/C cockpit for at least eight hours. CAS Manned A/C component of CAS shall be mounted via industrial suction cups to A/C windshield. CAS Added mass to suas shall be distributed about center of mass to maintain original mass distribution. CAS Power supply for suas mountable component of CAS shall be rechargeable. CAS Power supply for suas mountable component of CAS shall provide charge after a single charge cycle for a minimum of 30 minutes. CAS Technical installation of manned aircraft component should require <5 minutes for full functionality. CAS LEDs shall be implemented into manned A/C component circuitry to indicate power to component, sufficient battery life, GPS lock, and packet integrity. CAS Critical LEDs shall be implemented into suas mountable component circuitry to indicate power to component and verify system is on and software running. Risks 47

48 Inspection Functional Level System Level Requirement Number CAS.2.4 Requirement Manned A/C CAS component printed circuit boards (PCBs) shall be shielded from cockpit environmental factors detrimental to electronics functioning. CAS.2.5 Manned A/C component housing shall be detachable from any stationary functioning location in the manned A/C cockpit. CAS Initial MAEC shall have a semi-minor half-angle of 1.71 and a semi-major half angle of 5.71, as defined by expected manned A/C and suas velocities in a typical flight regime. CAS MAEC volume shall enclose the manned A/C such that the cross-section of the cone will grow from an ellipse enclosing the manned A/C dimensions to one that adds 60m to the minor axis and 200m to the major. CAS Manned A/C mountable element of CAS shall have redundant system to ensure packet integrity. CAS Manned A/C mountable element of CAS shall comply with 14 CFR so as not to impinge upon the operation of the existing navigation or communication systems. CAS Critical Manned A/C mountable element of CAS shall be powered by a designated power supply external to all A/C systems. Risks 48

49 Inspection (cont.) Functional Level Requirement Number Requirement CAS Manned A/C component of CAS shall be mounted via industrial suction cups to A/C windshield. CAS LEDs shall be implemented into manned A/C component circuitry to indicate power to component, sufficient battery life, GPS lock, and packet integrity. CAS suas elements of CAS shall be secured within the suas airframe. CAS LEDs shall be implemented into suas mountable component circuitry to indicate power to component and verify system is on and software running. CAS Telemetry data for collision avoidance maneuvers shall be stored on suas onboard memory. CAS Telemetry system for CERUNAS avoidance maneuvers shall be included in full suas component mass budget for test vehicle. CAS Telemetry shall be stored in a format which allows for direct download to a standard laptop or desktop computer. CAS Critical Unit count to lower per unit price by mass production shall be driven by conservative manufacturer price. Risks 49

50 Analysis System Level Level Requirement Number Requirement CAS.2 The manned A/C mountable element of the CAS shall not interface with existing manned A/C components while maintaining the capability to indicate either the location and heading of the A/C or encounter cone boundaries. CAS.4 CAS.6 The suas elements of the CAS shall have minimal impact on existing suas componentry. of the CERUNAS system designed for both the manned A/C and suas platforms shall be mass reproducible for less than $100. CAS.1.2 The post-cerunas avoidance region shall be determined by the initial MAEC. CAS.2.1 The suas mountable element of CERUNAS shall be able to sense edge of MAEC with an error of no greater than 3m. CAS.2.3 The manned A/C mountable element of the CAS shall not impact manned A/C flight dynamics or characteristics. CAS.3.1 All avoidance maneuvers implemented by the CAS shall comply with applicable FAA guidelines for suas operation. CAS.4.2 Critical The suas elements of the CAS shall draw no more than 0.3 W from pre-existing UAV power. Risks 50

51 Analysis (cont.) Functional Level System Level Requirement Number CAS.4.3 Requirement suas and manned A/C CAS component development shall promote ease of implementation. CAS.5.2 Telemetry data for any collision avoidance maneuvers shall be uniquely recorded for a period beginning at the maneuver start time and extending one (1) maneuver duration beyond the maneuver end time. CAS.5.1 Telemetry data for any collision avoidance maneuvers shall be saved on implemented suas internal data storage. CAS.5.3 The CAS elements for both the manned A/C and suas platforms shall be demonstrably reproducible for $100 +/- 10% based on manufacturer input. CAS Manned A/C mountable element of CAS shall comply with Title 14 Code of Federal Regulations (14 CFR) 21.21, 21.19, and such that no re-certification of aircraft type is required by installation of element. CAS Recovery of suas shall return vehicle to original, preencounter flight regime within a 10% tolerance with respect to pre-encounter suas velocity and maneuver CAS CAS CAS Critical Added mass to suas shall be distributed about center of mass to maintain the suas center of gravity. The battery powering CERUNAS suas components shall represent no more than 60% of the total CERUNAS mass budget. CAS telemetry system shall support sufficient memory to save data for all avoidances maneuvers plus two (2) average maneuver duration times. Risks 51