초록 ▼

The airspeed limiting performance envelope of a helicopter is converted to a groundspeed envelope by factoring-in the wind speed and direction. A groundspeed command for an unmanned helicopter is provided as a function of the range to the helicopter's destination. The function may be calculated so a

The airspeed limiting performance envelope of a helicopter is converted to a groundspeed envelope by factoring-in the wind speed and direction. A groundspeed command for an unmanned helicopter is provided as a function of the range to the helicopter's destination. The function may be calculated so as to provide a nominal groundspeed command equal to a nominal groundspeed command limit, or the function may be a fixed function to cause the aircraft to creep toward final approach. The cosine and sine of the desired relative flight direction of the aircraft, which is equal to the true bearing to the destination minus the true heading of the aircraft, are utilized to scale the groundspeed command into a longitudinal groundspeed command and a lateral groundspeed command. If one of the groundspeed commands is over a corresponding limit, the other groundspeed command is scaled back so that the vector addition of the two commands will cause flight in the desired direction. Exceedance of either a right or left groundspeed command, as well as saturation of the right or left cyclic pitch channel will cause the aircraft heading to be yawed into the direction of the limit exceedance or channel saturation.

대표청구항 ▼

[ We claim:] [1.] Apparatus for providing a groundspeed envelope for a helicopter, comprising:means providing a true wind direction signal indicative of the direction of wind in the environment of the helicopter;means providing a true heading signal indicative of the true heading of the helicopter;m

[ We claim:] [1.] Apparatus for providing a groundspeed envelope for a helicopter, comprising:means providing a true wind direction signal indicative of the direction of wind in the environment of the helicopter;means providing a true heading signal indicative of the true heading of the helicopter;means providing a wind speed signal indicative of the speed of the wind in the environment of the helicopter; andmeans for providing a relative wind direction signal as the difference between said true wind direction signal and said true heading signal, for providing a longitudinal wind speed signal as the wind speed signal multiplied by the cosine of said relative wind direction signal, for providing a lateral wind speed signal as the product of said wind speed signal and the sine of said relative wind direction signal, for providing a forward airspeed limit signal, an aft airspeed limit signal, a right airspeed limit signal, and a left airspeed limit signal, said limit signals being indicative of the airspeed safety envelope of the helicopter, for providing a forward groundspeed limit signal as a summation of said longitudinal wind speed signal and said forward airspeed limit signal, for providing an aft groundspeed limit signal as a summation of said longitudinal wind speed signal and said aft airspeed limit signal, for providing a right groundspeed limit signal as a summation of said lateral wind speed signal and said right airspeed limit signal, and for providing a left groundspeed limit signal as a summation of said lateral wind speed signal and said left airspeed limit signal.