Fadec- full authority digital engine control-latest

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Full authority, digital, engine, control, FADEC, EEC, computer, aviation, troubleshooting, memory recall, life monitoring, Redundancy, Training, Modern trends, Markov Analysis, Input Parameters, operations, performance, efficiency, Trimming.

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Fadec- full authority digital engine control-latest

  1. 1. FADEC
  2. 2. <ul><li>What is FADEC? </li></ul><ul><li>Digital Electronic Controls </li></ul><ul><li>Design Requirements : Modern Engine Control System </li></ul><ul><li>Why is FADEC Preferred? </li></ul><ul><li>A Backgrounder </li></ul><ul><li>Location of FADEC </li></ul><ul><li>Electronic Aspects of FADEC </li></ul><ul><li>How does FADEC work? </li></ul><ul><li>FADEC : Functions </li></ul><ul><li>FADEC : Essential Features </li></ul><ul><li>FADEC : Infrastructure (Simplified) </li></ul><ul><li>Schematic Diagram </li></ul><ul><li>Advantages & Limitations </li></ul>FADEC
  3. 3. <ul><li>WHAT IS FADEC? </li></ul><ul><li>FADEC: (Full Authority Digital Engine Control System) </li></ul><ul><li>a digital electronic control system </li></ul><ul><li>able to autonomously control the engine </li></ul><ul><li>- throughout its whole operating range </li></ul><ul><li>- in both normal and fault conditions </li></ul><ul><li>- has a self-monitoring, self-operating, redundant & fail-safe setup </li></ul><ul><li>- comprises of a digital computer and the other accessories (that control all the aspects of aircraft engine performance) </li></ul>
  4. 4. <ul><li>WHAT IS FADEC? </li></ul><ul><li>key system of gas turbine engines </li></ul><ul><li>purpose is to provide optimum engine efficiency for a given flight condition </li></ul><ul><li>also controls engine starting and restarting. </li></ul><ul><li>- lowers the work-load of pilots </li></ul><ul><li>- reduces the occurrence of pilot errors . </li></ul><ul><li>provides for efficient engine operation </li></ul><ul><li>also allows the manufacturer to program engine limitations and receive engine health and maintenance reports. </li></ul>
  5. 5. <ul><li>WHAT IS FADEC? </li></ul>- no form of manual override available - places full authority to the control of operating parameters of the engine in the hands of the computer. - if a total FADEC failure occurs, the engine fails. Note: If the engine is controlled digitally and electronically but allows for manual override, it is considered solely an Electronic Engine Control (EEC) or Electronic Control Unit (ECU). An EEC, though a component of a FADEC, is not by itself FADEC. When standing alone, the EEC makes all of the decisions until the pilot wishes to intervene.
  6. 6. <ul><li>DIGITAL ELECTRONIC CONTROL </li></ul>The benefits of digital electronic control of mechanical systems are evident in greater precision and an ability to measure or predict performance degradation and incipient failure. Typical examples of this are digital implementations of flight control or fly-by-wire (FBW) and digital engine control, or Full-Authority Digital Engine Control (FADEC). Integrated Flight and Propulsion Control (IFPC) allows closer integration of the aircraft flight control and engine control systems. Flight control systems are virtually all fly-by-wire in the modern fighter aircraft of today; the benefits being weight reduction and improved handling characteristics.
  7. 7. DESIGN REQUIREMENTS OF MODERN ENGINE CONTROL SYSTEM <ul><li>Speed / Accuracy / Ease of Control (Least Aircrew Workloads) </li></ul><ul><li>Wide Operational Range </li></ul><ul><li>Reliability & Operational Safety </li></ul><ul><li>Low Operating & Maintenance Costs </li></ul><ul><li>Should Not Add Weight </li></ul><ul><li>Fuel Efficiency </li></ul><ul><li>Dependable Starts </li></ul>
  8. 8. <ul><li>WHY IS FADEC PREFERRED? </li></ul>New engines are likewise adopting FADEC for the benefits offered by digital control, improved reliability and performance, weight reduction and other improvements in system integration and data flow.
  9. 9. A BACKGROUNDER <ul><li>The FADEC systems were first used in the automotive Industry where it is well proven. </li></ul><ul><li>Now-a-days airlines and the militaries all over the world incorporate it on turbine powered aircraft. </li></ul><ul><li>FADECs are made for piston engine and jet engines both but they differ in the way of controlling the engine . </li></ul><ul><li>Advanced, intelligent & robust propulsion controls are critical for improving the safety and maintainability of future propulsion systems. </li></ul><ul><li>Propulsion system reliability is considered to be critical for aircraft survival. Hence, FADEC systems came into being. </li></ul>
  10. 10. A BACKGROUNDER <ul><li>FADEC is now common on many engines and semiconductor and equipment cooling technology has advanced so that control units can now be mounted on the engine and still provide highly reliable operation for long periods. </li></ul><ul><li>Developing and implementing modern intelligent engine systems requires the introduction of numerous sensors, actuators and processors to provide the advanced functionality. </li></ul>
  11. 11. A BACKGROUNDER <ul><li>The application of artificial intelligence and knowledge-based system for both software and hardware provides the foundation for building the intelligent control system of the future. </li></ul><ul><li>With time, control systems became more sophisticated with the introduction of additional engine condition sensors and multiple servo-loops. </li></ul>
  12. 12. A BACKGROUNDER <ul><li>The task of handling engines was eased by the introduction of electronic control in the form of magnetic amplifiers in early civil and military aircraft. </li></ul><ul><li>The mag-amp allowed engines to be stabilized at any speed in the throttle range by introducing a servo-loop with engine exhaust gas temperature as a measure of engine speed and an analogue fuel valve to control fuel flow. </li></ul>
  13. 13. A BACKGROUNDER <ul><li>Transistors, integrated circuits and high temperature semi-conductors have all played a part in the evolution of control systems from range temperature control through to full digital engine control systems. </li></ul><ul><li>This allowed the pilot to accelerate and decelerate the engine while the control system limited fuel flows to prevent over- speeds or excessive temperatures. </li></ul>
  14. 14. A BACKGROUNDER <ul><li>With modern FADEC systems there are no mechanical control rods or mechanical reversions, and the pilot can perform carefree handling of the engine throughout the flight envelope. </li></ul><ul><li>On modern aircraft the engine is supervised by a computer to allow the pilot to operate at maximum performance in a combat aircraft or at optimum fuel economy in a passenger carrying aircraft. </li></ul>
  15. 15. A BACKGROUNDER <ul><li>Today, each FADEC is unique and therefore is expensive to develop, produce, maintain, and upgrade for its particular application. </li></ul><ul><li>In the future, it is desired to establish a universal or common standard for engine controls and accessories. This will significantly reduce the high development and support costs across platforms. </li></ul>
  16. 16. <ul><li>LOCATION OF FADEC </li></ul>FADEC is normally located on the engine fan casing. Therefore, FADEC cooling is difficult. However, there are many features of engine control which are distributed around the engine – such as reverse thrust, presently pneumatically actuated – which would need to be actuated by alternative means in a more-electric engine. This leads to the possibility of using distributed engine control.
  17. 17. <ul><li>ELECTRONIC ASPECTS OF FADEC </li></ul>Modern ECUs use a microprocessor which can process the inputs from the engine sensors in real time. An electronic control unit contains the hardware and software (firmware). The hardware consists of electronic components on a printed circuit board (PCB), ceramic substrate or a thin laminate substrate. The main component on this circuit board is a microcontroller chip (CPU). The software is stored in the microcontroller or other chips on the PCB, typically in EPROMs or flash memory so the CPU can be re-programmed by uploading updated code or replacing chips. This is also referred to as an Electronic Engine Management System (EMS).
  18. 18. <ul><li>HOW DOES FADEC WORK? </li></ul>FADEC works by receiving multiple input variables of the current flight condition including air density, throttle lever position, engine temperatures, engine pressures, and many others. Each FADEC is essentially a centralized system, with a redundant, central computer and centrally located analog signal interfacing circuitry for interfacing with sensors and actuators located throughout the propulsion system.
  19. 19. <ul><li>Engine operating parameters such as fuel flow, stator vane position, bleed valve position and others are computed from this data and applied as appropriate. </li></ul><ul><li>For example, to avoid exceeding a certain engine temperature, the FADEC can be programmed to automatically take the necessary measures without pilot intervention. </li></ul><ul><li>The inputs are received by the EEC and analyzed up to 70 times per second. </li></ul><ul><li>HOW DOES FADEC WORK? </li></ul>
  20. 20. <ul><li>HOW DOES FADEC WORK? </li></ul>FADEC computes the appropriate thrust settings and applies them. During flight, small changes in operation are constantly being made to maintain efficiency. Maximum thrust is available for emergency situations if the throttle is advanced to full, but remember, limitations can’t be exceeded. Another new feature of the FADEC system is the ability to record the last 900 hours of flight. With readings taken every second, this stored information can be used to diagnose problem areas as well as review recent flight history.
  21. 21. FADEC : FUNCTIONS FADEC ENGINE CONTROL ACQUIRE SENSOR DATA PROCESS CONTROL LAWS COMMAND ACTUATORS AIRFRAME COMMUNICATION REPORT ENGINE STATUS RECEIVE ENGINE POWER COMMAND ENGINE HEALTH MONITORING DIAGNOSTIC PROGNOSTIC ADAPTIVE
  22. 22. FADEC : ESSENTIAL FEATURES <ul><li>Conrol & Monitoring of Engine Operations </li></ul><ul><li>Dual Channels & Redundancy </li></ul><ul><li>Engine Life Monitoring </li></ul><ul><li>Record of Engine Performance Parameters </li></ul><ul><li>Automated Troubleshooting </li></ul><ul><li>Memory Read or Recall of Engine Data </li></ul><ul><li>Control of Common Engine Problems </li></ul><ul><li>Display of Warnings </li></ul><ul><li>Adaptation </li></ul><ul><li>Isochronous Idle Speed </li></ul>
  23. 23. FADEC : INFRASTRUCTURE <ul><li>CONTROL OPERATIONS IN GAS TURBINE ENGINES </li></ul>
  24. 24. FADEC : INFRASTRUCTURE <ul><li>CONTROL OPERATIONS IN GAS TURBINE ENGINES </li></ul><ul><li>- Air Control (Compressor Entry) </li></ul><ul><li>- Fuel Control (Main / AB / Starting System) </li></ul><ul><li>- Starting & Ignition Control </li></ul><ul><li>- Lubrication Control </li></ul><ul><li>- Surge Control (Through Bleed Valve) </li></ul><ul><li>- Thrust Control (Through Exhaust Nozzle) </li></ul><ul><li>- Vibration Control (Through Air / Fuel Control) </li></ul>
  25. 25. FADEC : INFRASTRUCTURE <ul><li>SAMPLE CHAIN OF CONTROL (MECH.) OPERATION </li></ul>FADEC COMPUTER GEAR DRIVEN MECHANICAL PUMP ELECTRO-HYDRO-MECHNICAL CONTROL UNIT ACTUATED ASSEMBLY SOLENOID VALVES SERVO ACTUATING MOTORS WORKING FLUID FROM ENGINE / AIRCRAFT AIRCRAFT COMPUTER COCKPIT POSITION SENSORS MECHANICAL ACTUATORS POSITION SENSOR-1 POSITION SENSOR-2
  26. 26. FADEC : INFRASTRUCTURE <ul><li>SAMPLE CHAIN OF CONTROL (ELECT.) OPERATION </li></ul>ELECTRO-HYDRO-MECHNICAL CONTROL UNIT POSITION SENSOR-1 SOLENOID VALVES SERVO ACTUATING MOTORS POSITION SENSOR-2 POSITION SENSORS MECHANICAL ACTUATORS FADEC COMPUTER POWER SUPPLY VARIOUS INPUTS FROM ENGINE & AIRCRAFT DISPLAY PANEL IN COCKPIT PILOT’s THROTTLE IN COCKPIT
  27. 27. FADEC : INFRASTRUCTURE <ul><li>HARDWARE: </li></ul><ul><li>- Dual Power Supply </li></ul><ul><li>FADEC Computer (With Logic Circuit PCBs & Programmed / Programmable Memory) </li></ul><ul><li>A Set of Servo Actuating Motors / Solenoid Valves / Position Sensors (for every System Control Unit) </li></ul><ul><li>Dual Position Sensors for Actuators (of every System) </li></ul><ul><li>A Set of Electrical Harnesses (for every System) </li></ul><ul><li>Display Panel with Indicators / Warning Lights (in Cockpit) </li></ul><ul><li>Multiple Engine RPM, Pressure Sensors & Thermocouples </li></ul><ul><li>Pilot’s Throttle </li></ul>
  28. 28. FADEC : INFRASTRUCTURE <ul><li>SOFTWARE: </li></ul><ul><li>- EPR Schedules (For Thrust, over Entire Range of Engine Operation Without FADEC Computer Failure) </li></ul><ul><li>N Schedules (For Thrust as per Pilot’s Throttle, Engine Operation in case of Limited FADEC Computer Functionality) </li></ul><ul><li>Note: In case of certain degree of FADEC failure there is an automatic mode switch-over from EPR to N rating. However, if the failure disappears, the pilot can reset the mode to switch-back to EPR mode. </li></ul>
  29. 29. FADEC : INFRASTRUCTURE <ul><li>INPUTS: </li></ul><ul><li>From Aircraft. </li></ul><ul><ul><ul><li>Ambient Temperature </li></ul></ul></ul><ul><ul><ul><li>Altitude </li></ul></ul></ul><ul><ul><ul><li>Mach Number </li></ul></ul></ul><ul><ul><ul><li>Angle of Attack </li></ul></ul></ul><ul><ul><ul><li>Impact Pressure </li></ul></ul></ul><ul><ul><ul><li>Landing Gear Position </li></ul></ul></ul><ul><ul><ul><li>Missile / Rocket Firing Signals etc. </li></ul></ul></ul>
  30. 30. FADEC : INFRASTRUCTURE <ul><li>INPUTS: </li></ul><ul><ul><ul><li>From Engine. </li></ul></ul></ul><ul><ul><ul><li>Throttle Lever Position </li></ul></ul></ul><ul><ul><ul><li>RPM </li></ul></ul></ul><ul><ul><ul><li>Turbine Outlet / Exhaust Gas Temperature </li></ul></ul></ul><ul><ul><ul><li>Exhaust Nozzle Area </li></ul></ul></ul><ul><ul><ul><li>Fan Duct Flaps Position </li></ul></ul></ul><ul><ul><ul><li>Bearing Temperatures </li></ul></ul></ul><ul><ul><ul><li>Engine Vibration </li></ul></ul></ul><ul><ul><ul><li>Engine Pressures </li></ul></ul></ul>
  31. 31. FADEC : INFRASTRUCTURE <ul><li>SIMPLIFIED FADEC ARCHITECTURE </li></ul>FADEC LANE-A MONITOR FADEC LANE-A CONTROL FADEC LANE-B MONITOR FADEC LANE-B CONTROL FADEC LANE-A FADEC LANE-B ENGINE THRUST DEMAND ENGINE FUEL DEMAND
  32. 32. FADEC : INFRASTRUCTURE <ul><li>SIMPLIFIED FADEC ARCHITECHTURE </li></ul><ul><li>This simplified architecture is typical of many dual-channel FADECs. </li></ul><ul><li>There are two independent lanes: Lane A and Lane B. Each lane comprises a Command and Monitor portion, which are interconnected for cross monitoring purposes, and undertakes the task of metering the fuel flow to the engine in accordance with the necessary control laws to satisfy the flight crew thrust command. </li></ul><ul><li>The analysis required to decide upon the impact of certain failures in conjunction with others, requires a Markov model in order to be able to understand the dependencies. </li></ul>
  33. 33. FADEC : INFRASTRUCTURE <ul><li>MARKOV ANALYSIS MODEL </li></ul><ul><li>By using this model the effects of interrelated failures can be examined. </li></ul><ul><li>The model has a total of 16 states as shown by the number in the bottom right-hand corner of the appropriate box. </li></ul><ul><li>Each box relates to the serviceability state of the Lane A Command (Ca) and Monitor (Ma) channels and Lane B Command (Cb) and Monitor (Mb) channels. </li></ul><ul><li>These range from the fully serviceable state in box 1 through a series of failure conditions to the totally failed state in box 16. </li></ul><ul><li>Clearly most normal operating conditions are going to be in the left-hand region of the model. </li></ul>
  34. 34. FADEC : INFRASTRUCTURE <ul><li>MARKOV MODEL ANALYSIS </li></ul>CaMa.CbMb 1 CaMa. Cb Mb 4 Ca Ma.CbMb 2 Ca Ma .CbMb 3 CaMa.Cb Mb 5 Ca Ma. CbMb 14 CaMa . Cb Mb 12 CaMa .Cb Mb 13 Ca Ma . CbMb 15 CaMa . CbMb 16 Ca Ma.Cb Mb 8 CaMa .CbMb 6 Ca Ma. Cb Mb 7 Ca Ma . Cb Mb 9 Ca Ma .Cb Mb 10 CaMa. CbMb 11 CONTROLLABLE ENGINE DISPACHABLE ENGINE ENGINE SHUT-DOWN NO FAILURE 1 FAILURE 2 FAILURES 3 FAILURES 4 FAILURES
  35. 35. FADEC : INFRASTRUCTURE <ul><li>Concentrating on the left-hand side of the model it can be seen that the fully serviceable state in box 1 can migrate to any one of six states: </li></ul><ul><ul><li>Failure of Command channel A results in state 2 being reached. </li></ul></ul><ul><ul><li>Failure of Monitor channel A results in state 3 being reached. </li></ul></ul><ul><ul><li>Failure of Command channel B results in state 4 being reached. </li></ul></ul><ul><ul><li>Failure of Monitor channel B results in state 5 being reached. </li></ul></ul><ul><ul><li>Failure of the cross-monitor between Command A and Monitor A results in both being lost simultaneously and reaching state 6. </li></ul></ul><ul><ul><li>Failure of the cross-monitor between Command B and Monitor B results in both being lost simultaneously and reaching state 11. </li></ul></ul>
  36. 36. FADEC : INFRASTRUCTURE <ul><li>All of these failure states result in an engine which may still be controlled by the FADEC. However, further failures beyond this point may result in an engine which may not be controllable either because both control channels are inoperative or because the ‘good’ control and monitor lanes are in opposing channels or worse. </li></ul><ul><li>The model shown above is constructed according to the following rules: an engine may be dispatched as a ‘get-you-home’ measure provided that only one monitor channel has failed. </li></ul><ul><li>This means that states 3 and 5 are dispatchable: but not states 2, 4, 6, or 11 as subsequent failures could result in engine shut-down. </li></ul>
  37. 37. FADEC : ESSENTIAL FEATURES <ul><li>MILITARY / TRANSPORT AIRCRAFT </li></ul><ul><li>- LP Compressor EGV Control & HP Compressor EGV Control </li></ul><ul><li>- Main Fuel Control </li></ul><ul><li>Core AB Fuel Control & Fan AB Fuel Control </li></ul><ul><li>Starting Fuel Control & Ignition Control </li></ul><ul><li>Bleed Valve Control & Fan Duct Flaps Control </li></ul><ul><li>Exhaust Nozzle Control </li></ul><ul><li>Lubrication Control & Vibration Control </li></ul>
  38. 38. FADEC : SCHEMATIC DIAGRAM AIRCRAFT COMPUTER PILOT IN COCKPIT MAIN FUEL CONTROL CORE AB FUEL CONTROL STARTING & IGNITION CONTROL FAN AB FUEL CONTROL EXHAUST NOZZLE CONTROL FAN DUCT FLAPS CONTROL BLEED VALVE CONTROL LP COMPRESSOR AIR EGV CONTROL HP COMPRESSOR AIR EGV CONTROL FADEC EECU POWER SUPPLY
  39. 39. CPU / Memory Actuation electronics Sensor electronics Sensor electronics Actuation electronics Sensor electronics Actuation electronics Actuator_1 Sensor_1 Sensor_ j Actuator_n Sensor_2 Actuator_2 Communication Power BUS FADEC Centralized Engine Control Communication CENTRALIZED CONTROL ARCHITECTURE Each function resides within the FADEC and uses unique point-to-point analog connections to system effectors.
  40. 40. CPU / Memory Actuation electronics Sensor electronics Sensor electronics Actuation electronics Sensor electronics Actuation electronics Actuator_1 Sensor_1 Sensor_ j Actuator_n Sensor_2 Actuator_2 Communication Power BUS FADEC Centralized Engine Control Communication DISTRIBUTED CONTROL ARCHITECTURE Functions are distributed outside of the FADEC and communicate via a common interface standard.
  41. 41. FADEC : ADVANTAGES <ul><li>- Reduced Aircrew Workload. </li></ul><ul><li>Improved Fuel Efficiency up to 15% (Due to faster, Accurate Engine Control no trimming is required). </li></ul><ul><li>Reduced Aircraft Weight and Engine Size (Due to Absence of Heavy Mechanical Assemblies, No Scattering of Pipelines & Electrical Wirings). </li></ul><ul><li>Improved Reliability (Due to Redundancy and Dual Channel). </li></ul><ul><li>Enhanced Engine Life (Due to Engine Operation in Safer / Mean Range). </li></ul>
  42. 42. FADEC : ADVANTAGES <ul><li>Minimum Maintenance due to On Board Computer Guided Troubleshooting ( Aircraft can return to Flying at the Earliest). </li></ul><ul><li>Isochronous Idle speed leads to Smoother Engine Starts. </li></ul><ul><li>- Maximum Performance in a combat aircraft or at Optimum Fuel Economy in a Transport Aircraft are possible after necessary Adaptation / Programming of FADEC Computer. </li></ul>
  43. 43. FADEC : ADVANTAGES <ul><li>- Auto-testing removes the need for test-running the engine after minor maintenance work ( Resulting in annual savings of millions of gallon of fuel for the fleet. </li></ul>
  44. 44. FADEC : LIMITATIONS <ul><li>Pilot can not override the FADEC Control. </li></ul><ul><li>In the event of complete FADEC Failure, pilot left with no other option than having to fly with least performance, just sufficient to land safely. (This limitation has been removed in modern transport aircraft by having two FADEC Computers.) </li></ul>
  45. 45. SAFE TAKE OFFs & LANDINGs ALWAYS FADEC
  46. 46. FADEC: ANY QUESTION ?

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