Aerodays 2011 DRESS presentation Distributed and Redundant Electro-mechanical nose wheel Steering System

Transcription

1 1 Aerodays 2011 DRESS presentation Distributed and Redundant Electro-mechanical nose wheel Steering System

2 2 DRESS CHARACTERISTICS AND OBJECTIVES European Commission funded project (FP6-3rd call - submitted in July 005) Schedule: Kick Off : June 2006 End : December 2009 Consortium: 13 partners from 8 countries 4 Industries 1 Research Institute 5 Universities 3 SMEs (Airbus, Messier-Dowty, Messier-Bugatti, Saab) (Institute of Aviation) (INSA, UHA, UCL, UCV, BUTE) (TTTech, Equipaero, Stridsberg) Budget Global total budget: Total funding:

3 3 DRESS CHARACTERISTICS AND OBJECTIVES Objectives: Study & Validate a redundant electromechanical actuator Study & Validate the control system based on a distributed architecture Particular attention to be paid to shimmy phenomenon (new system stiffness and damping of oscillations with an electromechanical system)

4 4 DRESS GENERAL PRESENTATION Background on nose wheel steering actuation: Hydraulically actuated steering systems used on current commercial aircraft Current probability for nose wheel steering system loss is low (10-5 / FH) In case of failure, the pilot can safely regain manual control using differential braking Current system safe, but limited if minimum visibility required (no CATIIIC landing) No potential automatic guidance relying on steering system Trend: - Effort to improve ATM (Air Traffic Management) - Move towards MEA (More Electric Aircraft)

5 DRESS TECHNICAL SPECIFICATIONS Functional analysis performed to identify the needs without focusing on olutions Main technical specifications, basis of DRESS design Maximum torque 7000Nm Maximum angular speed 20 /sec Towing mode capability (free to castor) Robust behavior regarding shimmy Total loss of steering event: objective 10-9/FH 5

6 6 DESCRIPTION OF DRESS SOLUTION Actuator architecture 2 identical path to apply torque at turning tube level Each path composed of -1 electric motor with its associated control unit - 1 prime reducer (cyclodrive) - 1 clutch - 1 end reducer (worm gear) Normal configuration Each path provide half of the demanded torque (torque summing) Failure of one path Remaining path provide the full torque (sizing for a limited number of occurrences)

7 DESCRIPTION OF DRESS SOLUTION System architecture (for potential future aircraft) based on field bus TTP (time trigger protocole) 3 cockpit RDC (acquisition node) 3 CPM (computation node) 3 Landing gear RDC (acquisition node) 2 EMCU (motor control unit) 3 angular sensors CAPT Tiller CAPT Brake Ped als Lan din g G ear Lever P ark Brake A/ SKID Sw itch F/ O Tiller O FF PU LL & TU R N PARK BRK ON A/SKID O N O FF Com mo n to ATA 32 System Specific to ATA 32 Braking Co ntrol System BCS DISCRETE Specific to ATA 32 Steering Co ntrol S ystem S CS Specific to ATA 32 L G E xtensio n Retraction System L GERS COCKPIT AVIONICS BAY NOSE LANDING GEAR BAY NOSE LANDING GEAR ANALOGUE and DISCRETE RDC ATA 32 BCS S CS L GERS RDC ATA 32 BCS S CS L GERS RDC ATA 32 BCS S CS L GERS AFDX A/C Avioni cs Bus AFDX CP M ATA 32 BCS SCS LGE RS CP M ATA 32 BCS SCS LGE RS CP M ATA 32 BCS SCS LGE RS Sp eci fic to ATA 32 Mo nito ring Contro l System ATA 32 Local Field Bus T TP CHA+CHB 2 CBGs BCS S CS LGE RS RDC ATA 32 SCS LGE RS RDC ATA 32 SCS LGE RS RDC ATA 32 SCS LGE RS DISC DISC DISC DISC E MCU E MCU P WM ANALOGUE P WM ANALOGUE DISC ANALOGUE DISC MO TOR MO TOR DISC RVDT RVDT RVDT F/ O Brake Ped als 7

8 8 DRESS PROTOTYPE Motor Key Characteristics Stritorque motor, embedding resolver position sensor, power off brake, temperature monitoring. Spline interface towards the transmission for bearing lifetime. EMCU Key Characteristics Motor torque control 270 VDC, 28 VDC Redundant, isolated RS-485 with Time- Triggered Protocol by TTTech. PWM motor drive with field-oriented control. The prototype EMCU overrated for the application.

9 9 DRESS PROTOTYPE ACTUATOR Cyclo reducer Clutch Worm gear Sized to withstand 55 C to 85 C NODE A TTP module board (provided by TTTECH) dedicated to manage TTP communications and to host the applicative software Clutch An IO-Board (HW and SW) developed by MB) dedicated to acquire sensors data (cockpit, VDTs, discrete, analog ) and controls actuators (Clutch, Brakes, ).

10 10 ACTUATOR RIG Actuator mounting frame with actuator load device The objective of this rig is to test the DRESS actuator under several conditions (load, temperature )

11 11 SYSTEM RIG (ATCSS CONFIGURATION) The objective of this rig is to test the DRESS system (steering precision and dynamic, avionic behavior, TTP functionality )

12 12 SYSTEM RIG (DCSS CONFIGURATION) The objective of this rig is to identify the system response to dynamic (up to 60Hz) excitation and allow a shimmy study(by modelisation).

13 13 OUTCOME OF DRESS Specification and design sizing case associated to an electromechanical teering system Electromechanical solution for steering actuation Improvement of safety objectives for a steering system ompliance with CATIIIC landings or automatic guidance system ) Shimmy damping with an electromechanical actuator Control of an active/active redundant actuator Use of a distributed architecture for system control Redundant and fail safe design of all electric aircraft systems

14 14 CONCLUSION DRESS solution not optimized for aircraft but generating lots of information Will enable accurate decisions for design choices on next aircraft generation (New Short Range)

15 15 Thank You for your attention