
c3ba833078699c5344462b217dc27657.ppt
- Количество слайдов: 10
MIT Space Systems Laboratory SPHERES 0 -G Autonomous Rendezvous and Docking Testbed Presented To DARPA Orbital Express December 2000 David W. Miller (617) 253 -3288 MIT, Cambridge MA millerd@mit. edu
SPHERES (AFRL-0012) CONCEPT OBJECTIVE — Provide a testbed for long duration, microgravity, low risk development of metrology, autonomy and control technologies in support of autonomous rendezvous and docking for Do. D and NASA missions. DESCRIPTION — — — Three 0. 25 meter diameter, 3. 0 kilogram, selfcontained satellites with on-board propulsion, processing, RF communication and metrology. Communicates with Shuttle/ISS Think. Pads (laptops) for Ku-band (up)downlink access. Patterned after MIT MODE (STS-40, 48, 62) and MACE (STS-67, ISS) controls laboratories. Successfully completed prototype testing on Air Force, NASA, and MIT funded KC-135 flights in Feb and Mar 2000. Manifested on ISS-9 a in May 2002
Using ISS to Mature Mission Technologies SPHERES on ISS is designed to mature algorithmic technologies (metrology, autonomy and control) for multi-vehicle autonomous rendezvous & docking. SPHERES has access to long duration m-G that allows 6 DOF per vehicle testing under large relative motions between vehicles in close proximity. SPHERES is a unique facility that allows algorithms at low TRL to be matured in a representative space environment — — Tolerant to risk associated with low TRL since crew can replenish consumables, terminate tests exhibiting anomalous behavior, etc. Fosters technology maturation due to crew observations, video coverage, and uplink of algorithms and downlink of data within days R&D has gone to great lengths to simulate the space environment in the research laboratory. Now, ISS simulates the research laboratory in space. SPHERES provides a low cost facility in space for developing & downselecting between algorithms for OE
Current Testing Using SPHERES Single SPHERE maneuver control on the KC-135 in February 2000 Multi-SPHERE formation flight coordination on the KC-135 Multi-SPHERE rendezvous and docking in the SSL 1 -G laboratory Future upgrades — — Emulate docking with a target vehicle in free drift Emulate a thruster failure in resupply vehicle Once docked, autonomously identify new inertia properties and reconfigure control Replace velcro with more advanced docking capability
Current Testing Using SPHERES Single and Multiple SPHERES units maneuvers in the KC-135, February and March 2000 — — Testbed Validation Initial Formation Flight
Current Testing Using SPHERES One-g SSL Laboratory Experiment — Development of 3 DOF rendezvous and docking using global coordinates
Relevance to DARPA’s Orbital Express (I) Orbital Express must demonstrate three key features — — (1) fuel transfer, (2) avionics upgrade & (3) routine auto. rendezvous & docking These are essential to replenishment, inspection, and repair of existing assets to lengthen life, recover from partial failures, upgrade technologies, and identify causes Fuel transfer demonstrated in Shuttle’s payload bay Avionics upgrade performed by astronauts on the Hubble Space Telescope: human-in-the-loop Rendezvous and docking demonstrated in limited forms — — Manual human-in-the-loop with Shuttle to MIR and ISS Automated with human-supervisorycontrol of Progress to MIR Orbital Express requires routine autonomous rendezvous & docking — — — Without human supervision With ability to adapt to low level anomalies That can accommodate cooperative, noncooperative, and eventually uncooperative target vehicles Routine autonomous rendezvous & docking is the most immature
Relevance to DARPA’s Orbital Express (II) Routine autonomous rendezvous & docking raises several questions — — — How does the problem change as different information becomes available from the two vehicles? — Both vehicles communicate and coordinate their motion — Target nulls residual velocities while docking vehicle performs all maneuvers — Docking vehicle must match residual motion of noncooperative target Can safe mode and recovery logic be developed that requires minimal human intervention? Can autonomous close proximity operations avoid collision and plume impingement? These define a wide design space which must be explored before committing these algorithms to OE flight demonstration The SPHERES Autonomous Rendezvous and Docking Testbed can be used to mature these algorithms in an environment that: — — Provides long duration micro-G for close proximity operations Is risk tolerant by allowing IFM and replenishment of consumables Has access to video coverage and Ku-Band (up)downlink facilitating iterative algorithm refinement Has low cost and high visibility
SPHERES (AFRL-0012) DETAILED OVERVIEW FLIGHT SYSTEM — — PRIORITY — Do. D SERB rank 15/34 Flight H/W (fits in 1 -1. 5 middeck lockers) — AF SERB rank 9/14 — 3 SPHERES, 4 metrology transmitters, 1 laptop (GFE) FUNDING NEEDED SPHERE satellite contents — Need $900 k to transition from high — CO 2 propulsion tank, RF fidelity prototype to operation on ISS communication, IR-ultrasonic global metrology, Inertial Measurement Unit — Flight hardware fabrication, STS(IMU), AA battery power ISS integration, operations Researcher uplinks algorithms, crew downloads from laptop, crew initiates test and — Potential non-DARPA sources include replenishes consumables, crew downloads and NASA ST-6 proposal & SBIR, and downlinks data to ground, researcher reviews Lockheed & AFRL data and refines algorithms, researcher uplinks refined algorithms. Cycle completed in days. STATUS — Currently manifested on ISS-9 a in May 2002 for 4 -6 months on ISS. High fidelity prototype built & operating in lab & KC-135, Phase 0/1 Safety Package complete, EMI tests conducted
SPHERES Team Capability MIT Space Systems Laboratory — David W. Miller — Formation flight, rendezvous and docking research in support of Techsat 21, ST-3, Terrestrial Planet Finder — Design and PI of 0 -g dynamics and controls laboratories — — MODE STS-40, 48, 62 DLS on MIR MACE STS-67, 106, ISS Jonathan P. How — Formation flight, differential GPS, robust control Brian Williams — Spacecraft autonomy, remote agent, Livingstone autonomous model-based diagnosis on DS-1 Payload Systems Incorporated — Developer and integrator of experiments in human-rated space platforms (Shuttle, MIR, ISS) The fact that our facilities have more reflights first flights is testimony to the versatility of, and demand for, our dynamics and controls laboratories
c3ba833078699c5344462b217dc27657.ppt