# Presentation: 663710

## Slide 1

**Mini AERCam**

- Dr. Steven E. Fredrickson
- Automation, Robotics, and Simulation Division / ER6
- NASA Johnson Space Center

**NASA Robotics Education Project Webcast Series**
**26 September 2002**

## Slide 2

**AERCam Concept**

- AERCam = Autonomous Extravehicular Robotic Camera
- Free-flying robotic platform for visual and non-visual sensing in support of human space activities
- Emphasis on “small” and increasingly “intelligent”
- NASA JSC development activities
- AERCam Sprint ISS Risk Mitigation Experiment (1997)
- AERCam Integrated Ground Demonstration of telepresence and autonomous capabilities for increasing operator productivity (1998)
- Mini AERCam lab demonstration of enhanced capabilities implemented in miniaturized hardware  (2000 - present)

## Slide 3

**AERCam Roles in Human Space Flight**

- Enhance extravehicular activity (EVA) crew productivity
- Pre-EVA site reconnaissance
- Additional camera views for IVA crew and ground controllers during EVA
- “Flashlight” service for EVA crew
- Post-EVA site close-out verification
- Provide better camera views for berthing and maintenance operations
- Arbitrary viewing angle and range for improved situational awareness
- Enhanced control of berthing operations with orthogonal camera views
- Close-out photography for “as built” configuration documentation

## Slide 4

**AERCam Roles in Human Space Flight (continued)**

- Provide telepresence inspection
- Close-up visual inspection of solar arrays, radiators, etc.
- Routine autonomous scanning
- Anomaly detection and reporting
- Photogrammetry
- Provide platform for sensor positioning in areas potentially inaccessible to EVA crew
- Chemical leak detection
- Infrared camera (e.g. thermal mapping)

## Slide 5

**Anticipated AERCam Mission Scenario for ISS**

- Mission scenario under either teleoperation or autonomous control:
- Deploy from home base
- Maneuver to region of interest while avoiding obstacles
- Perform desired inspection or viewing
- Provide views while stationkeeping
- Capture visual mosaic of region for future analysis
- Conduct real-time visual or non-visual inspection of region
- Return to home base
- Recharge power and propulsion

## Slide 6

**AERCam Sprint**

- AERCam Sprint completed a successful ISS Risk Mitigation Experiment (RME) on STS-87 in December 1997
- Hand launched/retrieved by EVA crew
- Teleoperated from aft flight deck
- Proved feasibility of free flyer for inspection
- 35 pound, 14 inch diameter cushioned sphere
- Automatic attitude hold capability
- Single string system with impact energy controls

## Slide 7

**AERCam Sprint**

## Slide 8

- Configuration
- Untethered robot on a granite air bearing table
- Indoor GPS pseudo-satellites
- Mockups of Shuttle bulkheads, payload bay obstacles, and space suit
- Demonstration results
- Autonomous point-to-point maneuvering accomplished using differential carrier phase Global Positioning System (GPS) navigation
- Obstacle avoidance achieved using proximity sensors and a path planner
- Dynamic object tracking performed using stereo machine vision
- Advanced inspection techniques demonstrated using an image mosaicking system

**AERCam Integrated Ground Demonstration**

## Slide 9

**Mini AERCam Overview**

- Goal:  Develop an enhanced-capability “nanosatellite” AERCam
- Miniaturized AERCam Sprint-like free-flying camera system with advanced capabilities on path to operational system
- ~7.5 inch diameter sphere
- ~20% of AERCam Sprint volume
- Plan:  Develop and integrate lab demonstration unit in approximate form, fit, and function of a miniaturized flight configuration
- Free-flyer hardware will be demonstrated on an airbearing table
- On-orbit operational simulation with hardware-in-the-loop testing will complement airbearing table demonstration

## Slide 10

_**X-MIR Inspector**_
- Size: 22” Dia. x 36” Tall
- Mass: 159 lb
- Payload: 1 Camera

_**AERCam Sprint**_
- Size: 13.5” Sphere
- Mass: 34 lb
- Payload: Two Cameras

_**Mini AERCam**_
- Size: 7.5” Sphere
- Mass: 11 lb
- Payload: Three Cameras

_**PSA    **_
- Size: 12” Sphere

**Where Does Mini AERCam Fit?**

## Slide 11

**Mini AERCam Technologies**

- Rechargeable pressurized xenon gas propulsion system
- 6 DOF thrusting capability (12 thruster configuration)
- Compatible with nitrogen for ground operations
- Rechargeable batteries (Li-Ion chemistry)
- CMOS color cameras  (“Camera on a chip” technology)
- Solid state illumination (LEDs)
- Avionics
- PowerPC 740 based design
- I2C digital sensor network

## Slide 12

**Mini AERCam Technical Concept Overview (continued)**

- Communications
- Digital transceiver for video, commands, and telemetry
- Micro-patch antennas for communications and GPS navigation
- GN&C
- MEMS angular rate gyros for propagated relative attitude
- Relative navigation via GPS mini-receiver
- Pilot aids:  AAH, LVLH hold, attitude maneuvers, translation hold, point-to-point guidance

## Slide 13

- Top Hemisphere

- GSE Port (x2)

- Bottom Hemisphere

- Power Button Cluster

- Refuel Cluster

- Center Structural Ring

- Single Camera Cluster

- Transceiver Package

- Dual Camera Cluster

- Gyro Package

- GPS Receiver

- LED Array

- Avionics Board

- Full Vehicle Integration Exploded View

## Slide 14

**Mini AERCam Flight System Concept**

## Slide 15

**Mini AERCam Development Progression and Roadmap**

## Slide 16

**Internal ISS Segment**

**External ISS Segment**

- GPS

- Transceiver

**Base Comm and Tracking (CAT) Unit**

**Wireless Ethernet **

- Pilot Control Displays

- Simulated On-Orbit Camera View

- Situational Awareness

**Laptop Control Station**
**Hand Controllers**

**Free-Flyer Segment**

**Mini AERCam Ground Test Concept: Airbearing Test **

**Ethernet **

**Air-Bearing Segment**

## Slide 17

**Internal ISS Segment**

**External ISS Segment**

- GPS

- Transceiver

**Base Comm and Tracking (CAT) Unit**

**Wireless Ethernet **

- Pilot Control Displays

- Simulated On-Orbit Camera View

- Situational Awareness

**Laptop Control Station**
**Hand Controllers**

**Free-Flyer Segment**

**Simulated GPS Constellation**

**Mini AERCam Ground Test Concept:              Orbital Simulation**

**Simulation Processor**

**Orbit Models**
**Vehicle Dynamics**

- God’s Eye View (Truth)

**Thruster Emulator**
**I/O**

**Gyro Emulator**
**I/O**

**Ethernet **

**Simulation Segment**

## Slide 18

**ISS Segment**

**GPS Simulator Segment**

**Simulation Segment**

**VxWorks / Host and In-Circuit Emulator**

**Housing for Gyro Emulator HW and Thruster Emulator HW**

**VME Chassis with PowerPC 750 and I/O Cards**

**Sun Workstation**

**Simulation “God’s-Eye View” PC**

**Rotational Hand Controller**

**Translational Hand Controller**

**Control Station**

**Situational Awareness Displays**

**Base Station GPS Receiver**

**Free-Flyer**

**Remote PC --> DEC Workstation --> RF Signal Generators**

**Orbital Simulation Computer Configuration**

## Slide 19

**Allocation of Demonstration Elements**

- *A substitute for RF Tracking will be used for the September 2002 Air Bearing Table Demonstrations

## Slide 20

**Orbital Simulation and Air-Bearing Table Milestones**

- S1: Manual 6-DOF Simulation with Control Station
- S2: Manual 6-DOF Simulation with AAH
- S3: Relative Navigation in Simulation with GPS Hardware
- S4: Automatic Translation Hold (ATH) in Simulation with GPS Hardware
- S5: Point to Point Guidance and Control in Simulation
- S6: Contingency Path Planning in Simulation

- A1: Manual 3-DOF on Air-Bearing Table
- A2: Manual 3-DOF on Air-Bearing Table with AAH
- A3: Relative Navigation on Air-Bearing Table (RF Tracking Substitute)
- A4: Automatic Translation Hold (ATH) on Air-Bearing Table
- A5: Point to Point Guidance and Control on Air-Bearing Table

**Orbital Simulation**

**Air-Bearing Table**

**Sim**

**Live**

**Live**

## Slide 21

**Conclusion**

- AERCam project is making significant progress toward a free-flying inspection capability to assist human space explorers
- AERCam Sprint ISS Risk Mitigation Experiment proved the viability of a free-flying camera platform
- AERCam Integrated Ground Demonstration developed autonomous capabilities for increasing operator productivity
- Mini AERCam is miniaturizing free-flyer hardware and implementing enhanced capabilities
- For more information visit the AERCam website:
-    http://aercam.jsc.nasa.gov