Design of FBW Flight Control Systems for Modern Combat Aircraft Shyam Chetty Former Director, CSIR-NAL Bangalore 1 IIT Dharwad 2018 1
ABOUT TEJAS Smallest, light-weight, supersonic aircraft Designed for multiple roles Fight other aircraft & establish control over airspace: highly agile, light weight, advanced radar, BVR missiles Spying on enemy (reconnaissance): Special Infra red sensors and cameras Bombing in enemy territory: can carry multiple combination of bombs, advanced radar, stealth, fire laser guided bombs Self-defense: Radar warning receivers, chaffs, flares to fool missiles Electronic warfare: electronic counter-measures Over 4500 flights on 27 Aircraft by 26 Pilots 2
TEJAS 3 View - Geometry S = 38.4 m 2 b = 8.2 m AR = 1.751 t/c ~ 3-4 % 50 o 62.5 o MAC = 5.6 m s max = 17.5 o, 27.5 o, 30 o -30 o to +30 o ab max = 60 o -25 o to +25 o L = 13.2 m 3
Required Capabilities of Combat Aircraft in Attacking Air Targets 4
Required Capabilities of Combat Aircraft in Attacking Ground (Surface) Objects 5
Fully Loaded War Machine 6
With Laser Guided Bombs for Precision Ground Attack LGB LDP 7
CONTROL CONFIGURED VEHICLE (CCV) AERODYNAMICS CONTROL ACT * STRUCTURES PROPULSION * - ACTIVE CONTROL TECHNOLOGY 8
SIX Degrees of Freedom of Motion LATERAL YAW AXIAL ROLL VERTICAL PITCH 9
Aircraft Primary Controls Rudder ( Yaw ) Engine ( Thrust) Elevator ( Pitch ) Aileron ( Roll ) 10
Aircraft Control (Pitch) Elevators Video 11
Aircraft Control (Roll) Aileron Aileron Video 12
Aircraft Control (Yaw) Rudder Video 13
CONVENTIONAL AIRCRAFT 14
FLY-BY-WIRE FLIGHT CONTROL Computers + Sensors Actuators 15
A Tale of 4 Forces & 2 Ratios 16
How Drag is Reduced? 17
How is L/D & T/W increased 18
Flight Control Laws Brain 19
FBW Flight Control Hardware 20
DFCC 21
ACTUATORS 22
SENSORS 23
FCS Software Development 24
TEJAS FCS OFP SOFTWARE FUNCTIONS REAL TIME EXECUTIVE (SYNCHRONIZATION, SCHEDULING) 25
TEJAS IFCS Test Facilities 26
Control Law Schematic Glimpses into the exciting world of modern aircraft design 27
Human Pilot Modeling & Pilot- Aircraft Coupling Glimpses into the exciting world of modern aircraft design 28
Control Law Block Schematic Glimpses into the exciting world of modern aircraft design 29
Cockpit Controls HOTAS Hands On Throttle & Stick (30 to 40 functions being controlled) 38
HOTAS Stick Grip 39
HOTAS Throttle Grip Glimpses into the exciting world of modern aircraft design 40
THROTTLE Grip Controls 41
Tejas Cockpit aircraft Ergonomics Glass Cockpit Tejas (TD1, TD2 & PV1) Tejas (PV2) 42
TEJAS Cockpit Glass Displays Cockpit 43
HUD Head Landing Up display Configuration (HUD) 44
Helmet Mounted Display Helmet Mounted Display 45
Man-Machine Interaction 46
Development of Multi Function Autopilot
Development of Multi Function Autopilot
Longitudinal Autopilot Modes Altitude Hold In this mode aircraft levels out in pitch (longitudinal axis) and altitude at the time level will be remembered and held. Altitude Select Pilot selects an altitude to reach and engages the mode The aircraft climbs or descents to the pilot selected altitude 42
Coupled Autopilot Modes Auto Level In this mode the aircraft is leveled out from unusual attitudes or from disorientation Approach Approach mode generates commands To capture and track the Localizer (LOC) To capture and hold the Glide Slope (GS) 36
Flight Director 37
H / V NAV Mode Selection 31
Autopilot Mode / State Transitions
The CLAW Design Cycle 48
SIMULATION PLATFORMS Engineer In Loop Pilot In Loop Inflight Simulators 49
Iron Bird FCS Test Rig 50
Iron Bird Facility 51
Structural Coupling Rig 52
Airframe Structural Modes 53
Test & Integration Facilities 54
TEJAS Lightning Tests 55
Work Centers of LCA Programme 56
Industry Participation in LCA Programme 57
58
Cold Weather Trials at -15 deg C at Leh 59
Amidst Majestic Himalayas Video 60
Hot Weather +45 deg. C Trials at Jaisalmer 61
Wake Clearance 62
Air to Air Refueling 63
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