Helicopter Flight Dynamics Unit 5 Helicopter Flight Controllers

Helicopter Flight Dynamics Unit 5: Helicopter Flight Controllers

Topics 1. External forces acting on helicopter 2. Control manners of helicopter 3. Control systems and their mechanical characteristic 4. The Development of helicopter controllers

External Forces Acting on Helicopter V V

Aerodynamic Forces of Main Rotor Thrust: T Hind force: H Side force: S Anti-torque: Mk Hub moments: MGx, MGz

Aerodynamic Forces of Tail Rotor V V Thrust: TT Anti-torque: Mk. T

Aerodynamic Forces of Fuselage Drag: Qf Lift: Yf V Side Force: Sf Roll Moment: Mxf Yaw Moment: Myf Pitch Moment: Mzf V

Aerodynamic Forces of Horizontal Tail V V Drag: Dh Lift: Yh

Aerodynamic Forces of Vertical Tail V V Drag: Dv Lift: Yv

Helicopter Control Manners • Control manners of helicopter with main rotor and tail rotor • Control manners of twin rotors helicopter • Control manners of tilt-rotor aircraft • Other control manners

Helicopter Types

Control of Fixed-wing Aircraft rudder elevator aileron

Control of Fixed-wing Aircraft Direct Control Indirect Control Degree of Freedoms Cockpit Control Unit Aerodynamic Surfaces Control Forces Forward Throttle Thrust T Pitch Stick Elevator MZ Roll Stick Aileron MX Yaw Paddle Rudder MY Altitude Stick + Throttle F Sideward Stick + Paddle S

Control of Helicopter Main Rotor Control System Engines Tail Rotor

Control of Helicopter with Main & Tail Rotors Degree of Freedoms Motions Cockpit Control Unit Aerodynamic Surfaces Control Forces Vertical Altitude Collective stick Rotor T Longitudinal Pitching, Forward & backward Stick Rotor H, MGz Lateral Rolling, sidestep Stick Rotor S, MGx Yaw Heading Rudder Tail rotor TT Main rotor is the lift surface to produce the lift of helicopter. On the other hand, it is the control surface to produce the forces or moments of heaving, pitching and rolling. Furthermore, it is the propeller to make helicopter to fly in any directions.

Comparison of Control Between helicopter and Fixed-wing Aircraft Direct Control Helicopter Indirect Control Fixed_wing Aircraft Direct Control Indirect Control Degree of Freedoms Cockpit Control Unit Aerodynamic Surfaces Control Forces Altitude Collective Rotor T Pitch Stick Rotor H, MGz Roll Stick Rotor S, MGx Yaw Rudder Tail rotor TT Forward Collective + stick H Sideward Collective + stick + Rudder S Forward Throttle Thrust T Pitch Stick Elevator MZ Roll Stick Aileron MX Yaw Paddle Rudder MY Altitude Stick + Throttle F Sideward Stick + Paddle S

Control of Tilt-rotor Aircraft Airplane Helicopter • • Thrust /power level controls Collective pitch and throttles Acts as altitude control • • Thrust /power level controls blade pitch and engine throttles Acts as altitude control Thrust/power Control

Control of Tilt-rotor Aircraft Helicopter Airplane Forward longitudinal cyclic pitch • • • Proprotor discs tilt forward Aircraft assumes nose-down altitude Airspeed increases • • elevator Elevator deflects downward Aircraft assumes nose-down altitude Altitude decreases Airspeed increases Forward Stick Control

Control of Tilt-rotor Aircraft Helicopter Airplane Backward longitudinal cyclic pitch elevator • • • Proprotor discs tilt backward Aircraft assumes nose-up altitude Airspeed decreases • • Elevator deflects upward Aircraft assumes nose-up altitude Altitude increases Airspeed decreases Backward Stick Control

Control of Tilt-rotor Aircraft Airplane Helicopter flaperon differential collective pitch and lateral cyclic pitch • • Right proprotor increase collective pitch Left proprotor decrease collective pitch Proprotor discs tilt to left Aircraft rolls to left • • • Right flaperon deflects downward Left flaperon deflects downward Aircraft rolls to left Left Stick Control

Control of Tilt-rotor Aircraft Helicopter Airplane differential collective pitch and lateral cyclic pitch • • flaperon Left proprotor increase collective pitch Right proprotor decrease collective pitch Proprotor discs tilt to right Aircraft rolls to right • • • Left flaperon deflects downward Right flaperon deflects downward Aircraft rolls to right Right Stick Control

Control of Tilt-rotor Aircraft Rudder Differential longitudinal cyclic Airplane Helicopter • • • Left proprotor disk tilts forward Right proprotor disk tilts backward Aircraft yaws to left • • Rudder deflect to left Aircraft yaws to left Left Pedal Control

Control of Tilt-rotor Aircraft Rudder Differential longitudinal cyclic Airplane Helicopter • • • Left proprotor disk tilts backward Right proprotor disk tilts forward Aircraft yaws to right • • Rudder deflect to right Aircraft yaws to right Right Pedal Control

The Development of Controller Smart Control System Helicopter flight dynamic model Commands from pilot Actuators Ambient disturbance Information from navigation sys. Airborne Computer Helicopter Sensors