Actuators Sensors Team Objectives Operate actuators and sensors

Actuators & Sensors Team • Objectives: Operate actuators and sensors to carry out mission control and scientific data collection tasks. • Requirements: Design sensor/controller interface hardware • Members: Nathir Rawashdeh (lead), Garrett Chandler, Chenxing Wang, Srinivasa Patri & Z. Cai BIG BLUE II CDR University of Kentucky

Section Outline • Deployed Sensors & Actuators • Ballistic Cutter Actuator Design • Risks and Testing BIG BLUE II CDR University of Kentucky

Deployed Sensors & Actuators • • • Compass GPS (navigation) GPS (APRS communication) Wing Strain UV Sensor Pressure (inflation tank, wing, absolute) Temperature (wing, external & internal) Accelerometers High Current Switch BIG BLUE II CDR University of Kentucky

Deployed Sensors & Actuators The following components are covered in the sections on Navigation & Communication: – Compass – GPS (for Navigation) (for APRS communication) BIG BLUE II CDR University of Kentucky

Deployed Sensors & Actuators The following sensors are being developed by the Mechanical Engineering. Necessary interface circuitry will be provided. – Wing Strain (scientific data) – UV Sensor (for wing curing process) – Pressure (inflation tank) see inflation group BIG BLUE II CDR University of Kentucky

Deployed Sensors & Actuators Pressure (wing) • • • Sensor: MPX 5100 DP Case 867 c, “Motorola” Range: 0 – 100 k. Pa (0 – 14. 5 psi) Output Range: 0. 2 t 4. 7 Volts Size: 0. 41 x 29. 4 x 29. 9 Operating Temp: -40 to 125 ºC BIG BLUE II CDR University of Kentucky

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Deployed Sensors & Actuators Pressure (absolute) • Use: compute altitude • Sensor: 15 PSI-A-4 v from “All Sensors” • Size: 1. 1” x 1. 08” x 1. 03” • Range: 0 ± 0. 3 to 15 psi • Output: Ratiometric 4 V • Temp: -25 to 85ºC, 5 to 50ºC compensated BIG BLUE II CDR University of Kentucky

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Deployed Sensors & Actuators Temperature (wing) • • • Wing temp. Important scientific data Use MAX 6674 thermocouple interface chip (? ) Size: 0. 197” x 0. 157” x 0. 069” (5 x 4 x 1. 75 mm) Weight: <. 035 oz. (< 1 g) Power Consumption: 1 m. A@3 V 8 -pin SO Package, SPI- compatible serial interface • Range: 0°C to +128 °C @ 0. 125 °C resolution • Accuracy: ± 2 °C for the range 0 °C to +125 °C • Interface: SPI BIG BLUE II CDR University of Kentucky

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Deployed Sensors & Actuators Temperature (external & internal) • • • Sensor: TMP 100 temp. sensor, “Texas Instr. ” Size: 0. 12” x 0. 067” x 0. 037” (3 x 1. 7 x 0. 95 mm) Power Consumption: 45µA@3 V Range: -55º to 125ºC, ± 1º , ± 0. 0625ºC resolution. Interface: I 2 C Interface 40 ms conversion rate, 25 conversions per second BIG BLUE II CDR University of Kentucky

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Deployed Sensors & Actuators Accelerometers • To collect scientific data, two accelerometers are used to measure the attitude of the aircraft (orientation of axes relative to the horizon) • Sensors: Analog Dev. ADXL 202 E and ADXL 210 • Power Consumption: <0. 6 m. A @ 3 V • Operating Temperature: -40 to 85 °C • Range: -2 to 2 g , -10 to 10 g • Interface: Duty cycle using 1 PCA input per axis BIG BLUE II CDR University of Kentucky

Deployed Sensors & Actuators Accelerometers … continued +3 V 8 8051 X channel Duty Cycle output 7 ADXL 202 E 1 Rset 6 5 Xout T 2 2 Yout 3 4 Y channel Duty Cycle output BIG BLUE II CDR University of Kentucky

Deployed Sensors & Actuators High Current Switch • Part: IPS 031 Power MOSFET from “International Rectifier” • Use: provide bursts of high current. For example, ballistic cutter, ATV cam, solenoid actuators etc. • Size: roughly 10 x 20 x 5 mm • Range: 12 A, 18 A bursts • Protected: shuts off if current>12 A or if too hot • Features: low-current logic level inputs BIG BLUE II CDR University of Kentucky

Deployed Sensors & Actuators High Current Switch … continued BIG BLUE II CDR University of Kentucky

Ballistic Cutter Actuator Tantalum Cap scalable BIG BLUE II CDR University of Kentucky

Ballistic Cutter Actuator Circuit BIG BLUE II CDR University of Kentucky

Future Needs Any necessary sensor or actuator interface circuitry will be provided as needed. For example: – Parachute or wing-door deployment verification signals – Wing lift measurements BIG BLUE II CDR University of Kentucky

Risks & Testing • Risks: – Sensor failure at low temperature/pressure – Interference & Errors can falsely trigger actuators – Low battery when deploying chute • Testing: Interactive during development and at launch site. Test functionality at low temp/pressure. BIG BLUE II CDR University of Kentucky

Telemetry Objective: Develop data strings for communication with ground stations and for logging data into the black box during the flight. Team members: Aaron Welch Archana Vasudevan Dale Reid Chun Guan Matt Field BIG BLUE II CDR University of Kentucky

Requirements • Provide high capacity local storage (black box) for telemetry data • Provide high bandwidth communication with ground • Develop reasonable coding scheme for telemetry data, possibly for each stage of flight BIG BLUE II CDR University of Kentucky

Flash Memory • Used in 2 subsystems: 2 MB black box and 8 MB storage for camera • SPI interface • 3 V compliant, so no regulation needed • Available in MMC packaging • Camera storage may be multiplexed chip selects to conserve I/O pins • Total I/O pins required: 4 on MC, 5 on camera (if multiplexing required) BIG BLUE II CDR University of Kentucky

Flash Memory • Data. Flash – – Atmel AT 45 DCB 004 8 MByte Capacity SPI Interface 2. 7 V - 3. 6 V Supply – – Two SRAM Buffers 13. 2 m. W Read Power 5 V Tolerant Inputs Environment: -40 to 85 C BIG BLUE II CDR University of Kentucky

Multiplexing Flash Cards Serial In, Serial Out, and Serial Clock lines will all be common connections BIG BLUE II CDR University of Kentucky

Telemetry String • • • Radios operate at 1200 baud Data rate to ground: ~2 seconds Black box data rate: variable String length to ground: 64 bytes String length to black box: 70 bytes If sufficient rate available, pictures can be sent down as well BIG BLUE II CDR University of Kentucky

Example Telemetry String Format • Bytes 1 to 28: GPS data. Includes time (hh: mm: ss), altitude, latitude, longitude, speed, track, and other data • Bytes 29 to 60: Sensor data • Bytes 61 and 62: Software tracking location • Byte 63: Health check bits • Byte 64: “/r” byte signaling end of string • Bytes 65 to 70: Sensor data only for logging BIG BLUE II CDR University of Kentucky

Byte Breakdown of Sensors • • • 29, 30: airspeed (differential pressure sensor) 31 -34: altitude (absolute pressure sensor) 35, 36: yaw rate (gyro) 37 -42: 3 -axis accelerometer 43, 44: compass 45 -48: wing pressure sensors (left and right) 49, 50: wing thermocouple 51, 52: tank pressure 53, 54: chute thermocouple 55, 56: internal temperature 57, 60: Mission length in seconds Byte 63: Health check • • Bit 0: Mission Control microprocessor Bit 1: Autopilot microprocessor Bit 2: Chute Control microprocessor Bit 3: Camera health Bit 4: ATV state (on/off) Bit 5: Wing/Inflation state Bit 6: Door state Bit 7: open Logged Data only • • • 65, 66: chip temperature 67, 68: external temperature 69, 70: UV intensity BIG BLUE II CDR University of Kentucky

Ground Program • Used to decode telemetry string for easy reading in realtime • Gives the ability for much more complex encoding schemes BIG BLUE II CDR University of Kentucky

Camera Sub-System • Objective Capture, process and store digital still images. • Requirements – – – 640 x 480 Pixel Resolution Storage for 100 Pictures Image Sensor Stable to -10 C Infinite Focal Length High Level Interface BIG BLUE II CDR University of Kentucky

Camera Sub-System Components Image Sensor JPEG Engine FLASH Storage 4 2 SPI RS-232 Camera Driver Data Bus Global Variables BIG BLUE II CDR University of Kentucky

Camera Sub-System Components • Camera Module – Image Sensor • Omnivision OV 7640 • Environment: -10 to 70 C • 640 x 480 x 16 bpp – JPEG Engine • Omnivision OV 528 • Configurable Compression • Serial Data Transmission • Atmel Data. Flash – AT 45 DCB 008 • C 8051 F 310 Processor – UART (Camera) – SPI (FLASH) – I 2 C (Data Bus) BIG BLUE II CDR University of Kentucky

Camera Sub-System Verification • In chamber: temperature and pressure. • On test plane: vibration and shock. • On bench: file system and data processing. BIG BLUE II CDR University of Kentucky

Parachute Control • Objective Deploy parachute to terminate mission as prescribed by the sequ • Team Members – – Garrett Chandler David Jackson Kevin Morris Muthulakshmi Muthukumarasamy – – Srinivasa Patri Osamah Rawashdeh Dale Reid Archana Vasudevan BIG BLUE II CDR University of Kentucky

Parachute Control Integration Mission Control Flight Control Accelerometers Airspeed Wing Actuators Compass Rate Gyros Flash Memory Altimeter Accelerometers Video Actuators Pressures Radio Temperatures GPS Chute Deploy Altimeter Chute Control Data Bus Cut Actuator Servos Global Variables CMOS - JPEG Flash Memory Camera Driver BIG BLUE II CDR University of Kentucky

Parachute Control Requirements • • Deploy at Fixed Minimum Altitude Deploy on Request from Mission Controller Signal Fault Tolerant Firing Circuit Automatically Identify and Respond to Error Conditions BIG BLUE II CDR University of Kentucky

Parachute Control Components Altimeter 2 Chute Actuator 4 1 analog TTL Chute Control Data Bus Altimeter 1 Global Variables GPS BIG BLUE II CDR University of Kentucky

Parachute Control Components • Processor – Silicon Labs 310 • Altimeter – All Sensors Corp. – 15 PSI-A-4 V (104 k. Pa) • Chute Actuator – Holex 5800 Guillotine – TTL Logic Interface BIG BLUE II CDR University of Kentucky

Parachute Control Failure Identification • Monitor Processors – Watchdog Counters in Global Variables – Reset Counters in Global Variables – Health Identifiers in Global Variables • Monitor Data Bus – Read/Write Tests to Global Variables • Monitor Power Bus – Backup Power Activated • Monitor Altitude – Minimum Set Point – High Rate of Decent BIG BLUE II CDR University of Kentucky

Parachute Control Verification • In chamber: simulated decent. • On test plane: decent rate, min. altitude. • On bench: awash in radio EMI. BIG BLUE II CDR University of Kentucky

Flight Testing • Flight Testing Team: – – – Andrew Simpson Arvind Santhanakrishnan Thomas Ritchie Daniel Porter Michiko Usui Bobby Jones BIG BLUE II CDR University of Kentucky

Flight Testing • Test fly individual pieces Test Flights Components Past Tests Required Tests Composite Wing 10 5 Wing Cure Sensor 0 0 Inflation System 0 0 Wing Door 0 0 Airframe 8 5 Tail 3 5 Parachute 6 5 Flight Control 0 10~15 Chute control 0 5 Mission Control 0 0 Sensors/Actuators 16 10 Telemetry 0 5 Still Camera 0 5 Communications 0 ATV 15 10 Total: 58 70 Feb 14 CDR March Preparation for Launch Flight Testing of Final Design Test fly final configuration Flight Testing of individual components Spring Break W/S Mechanical Component Electrical Component April May 5 Launch BIG BLUE II CDR University of Kentucky

Flight Testing • Test fly final configuration – Varying altitudes – Varying conditions • Drop test at low altitude – Measure G-loads – Apply to high altitude John Herbst’s Hot Air Balloon BIG BLUE II CDR University of Kentucky

Flight Testing • Obtain Lift and Drag for wing from wind tunnel • Test inviscid and viscous numerical models using CFD ( – Vary Re, Mach number, Alpha and Beta for final configuration BIG BLUE II CDR University of Kentucky

Action Items BIG BLUE II CDR University of Kentucky