Transcript FLY-BY-WIRE
SUBMITTED BY PRAMOD H S DEPT OF MECHATRONICS JSS POLYTECHNIC NANJANGUD HISTORY OF FBW Electronic signaling of the control surfaces was tested in the 1950s. This replaced long runs of mechanical and hydraulic connections with electrical ones. The first digital fly-by-wire aircraft to take to the air (in 1972) was an modified electronically The term "fly-by-wire" implies a purely electricallysignaled control system. It is used in the general sense of computer-configured controls. where a computer system is interposed between the operator and the final control actuators or surfaces. This modifies the manual inputs of the pilot in accordance with control parameters. Fly-By-Wire was designed so that the pilot moves his controls that provided electrical inputs into a computer. The computer then uses information from other inputs and then calculates the proper control changes. This command is transmitted by WIRE to an actuator or a servo back to the wing/tail which moves the control surface. INNER VIEW OF AN FBW Fly-by-wire control systems allow aircraft computers to perform tasks without pilot input. Automatic stability systems operate in this way. Gyroscopes fitted with sensors are mounted in an aircraft to sense movement changes in the pitch, roll and yaw axes. Any movement (from straight and level flight) REFERENCE MEASURED + ERROR CONTROLLER SYSTEM INPUT - MEASURED OUTPUT SENSOR SYSTEM SYSTEM OUTPUT THERE ARE TWO TYPES OF SYSTEMS IN FBW THEY ARE ANALOG SYSTEM DIGITAL SYSTEM Fly-by-wire replace hydromechanical or electromechanical flight control systems with electronic circuits. The control mechanisms in the cockpit now operate signal transducers, which in turn generate the appropriate electronic commands. These are next processed by controller with an analog signal. an electronic A digital fly-by-wire flight control system is similar to its analog counterpart. The signal processing is done by digital computers and the pilot literally can "fly-via-computer". It increases the flexibility of the flight control system. The digital computers can receive input from any aircraft sensor. This also increases the electronic stability, because the system is less dependent on the values. This eliminates mechanical contacts. The mechanical contacts are replaced by wires Due to the elimination of the mechanical contacts wear and tear is reduced. The control system used in this type is far more intelligent then the conventional system. APPLICATIONS OF DIGITAL FBW The F-8 digital fly-by-wire program served as the springboard for DFBW technology to be used in both military and civilian aircraft. satellite manufacturers also routinely technology in their vehicles and spacecraft. Space Shuttle Several unmanned aerial vehicles (UAVs) use the Analog system Digital system 1) Accuracy low 1) Accuracy high 2) Circuit Complication 2) circuit is simplified 3) Calibration is tough 3) calibration is easy This system has less or no drawbacks. But some of the people argue that the system containing software program is never free of troubles rather how many times it is been checked or serviced. Rather then software the failures of sensors may also be trouble. But this problems are not considered because the sensors are highly precise and developed for these types of system. ADVANCED AEROPLANES WHICH ARE BASED ON FBW SUKHOI-47 TYPHOON F-22 RAPTOR MI-35 Fly-by-wireless Power-by-wire Fly-by-optics Higher accuracy Due to the elimination of the mechanical contacts wear and tear is reduced. The control system used in this type is far more intelligent then the conventional system.