The Boeing Company

Boeing Commercial Airplane Company

Antonius A Lambregts

Rolf Hansen

Monte R Evans

In a method of flight control in which a thrust command is computed based on the total aircraft energy error relative to flight path and speed control commands, and an elevator command is computed based on the energy distribution error relative to the same flight path and speed control commands, an improvement is provided including an elevator control command in response to a column control input by the pilot. In the short term, the computing establishes a change in flight path angle beyond the sustainable flight path angle at the trim speed for the prevailing thrust condition. In the long term, the computing establishes a change in speed relative to a set reference speed, the speed change being proportional to the column control input. In the long term, the computing establishes a flight path angle equal to a sustainable value for the prevailing thrust condition and the altered speed condition.

Total energy based flight control system

A variable bandwidth factor KALT is applied in a total energy control system to obtain a reduction in throttle activity while maintaining system stability. The system has a total energy control loop and an energy distribution control loop. In the former, a net thrust command signal T.sub.c is generated to reduce the total energy error to zero. In the latter, an elevator position command signal .delta.e.sub.c is generated to reduce the energy rate distribution error, i.e. correct the distribution of energy between kinetic energy (speed) and potential energy (altitude). The error signal input into each loop has a flight path component and a speed component. The factor KALT is applied to both components of the total energy error to reduce the bandwidth of the total energy control loop with increasing altitude and thereby reduce throttle activity. The factor KALT is also applied to one of the components of the energy distribution error to prioritize reduction of that component to zero by control of elevator position. Preferably, speed control is prioritized, and energy errors are channeled into short term deviations in altitude.

Aircraft high altitude vertical flight path and speed control system

An aircraft's horizontal flight path and sideslip angle is controlled in a system having a roll control loop and a yaw control loop. An incremental aileron position command signal is generated in the roll control loop as a function of the sum of a yaw rate error and a sideslip error. An incremental rudder position command signal is generated in the yaw control loop as the function of the difference between these errors. The yaw rate error is determined as a function of a heading error. The manner in which the heading error is computed varies with the control mode in which the system is operating. In the simplest heading mode, the heading error is the difference between a heading command a sensed heading of the aircraft. In the inner loop of the roll control channel, a roll attitude command signal is generated as a function of heading error plus sideslip error. In the inner loop of the yaw control channel, a yaw rate command signal is generated as a function of heading error minus sideslip error. These inner loop command signals are combined with roll angle and yaw rate feedback, respectively, to produce a roll attitude error signal and a yaw rate error signal. The system also provides ground track angle and lateral navigation command modes.

Aircraft lateral-directional control system

A display system for use in an aircraft control wheel steering system provides the pilot with a single, quickened flight path angle display to overcome poor handling qualities due to intrinsic flight path angle response lags, while avoiding multiple information display symbology. The control law for the flight path angle control system is designed such that the aircraft's actual flight path angle response lags the pilot's commanded flight path angle by a constant time lag .tau., independent of flight conditions. The synthesized display signal is produced as a predetermined function of the aircraft's actual flight path angle, the time lag .tau. and command inputs from the pilot's column.

Aircraft flight path angle display system

Aircraft roll command signals are generated as a function of the Microwave Landing System based azimuth, groundtrack, groundspeed and azimuth rate or range distance input parameters. On initial approach, roll command signals are inhibited until a minimum roll command requirement is met. As the aircraft approaches the centerline of the runway, the system reverts to a linear track control.

Aircraft roll steering command system

An improved inner loop control is disclosed for use in an aircraft pitch axis control system. Signals representative of vertical acceleration and pitch rate are complementary filtered and summed to produce an 'inner loop' damping signal which is combined with 'outer loop' command signals to produce an elevator control signal. The improved approach provides higher outer loop control law gains and better system stability, resulting in higher control bandwidth and tighter command tracking, especially in turbulence.

Method and apparatus for an aircraft inner loop elevator control system

Disclosed is a vertical flight path angle steering system for aircraft, utilizing a digital flight control computer which processes pilot control inputs and aircraft response parameters into suitable elevator commands and control information for display to the pilot on a cathode ray tube. The system yields desirable airplane control handling qualities and responses as well as improvements in pilot workload and safety during airplane operation in the terminal area and under windshear conditions.

Vertical flight path steering system for aircraft

Upon aircraft landing approach, flare path command signals of altitude, vertical velocity and vertical acceleration are generated as functions of aircraft position and velocity with respect to the ground. The command signals are compared with corresponding actual values to generate error signals which are used to control the flight path.

Aircraft landing control system

Aircraft altitude, ground velocity, and altitude rate signals are input to a computer which, using a unique control law, generates a pitch control surface command signal suitable for guiding an aircraft on its flare path to a specified runway touchdown point despite varying wind conditions.

Method and apparatus for producing an aircraft flare path control signal

A landing approach system for aircraft utilizing ILS (instrument landing system) beam guidance information which converts angular glide slope information into linear altitude deviation relative to the glide slope beam center, using computed range information.

Independent glide slope gain programming system

A rate of change of energy computer utilizing signal processing of the inner vectorial product of inertial acceleration and inertial velocity wherein such parameters are derived utilizing outputs from the aircraft INS (inertial navigation system) and from body mounted accelerometers.

Apparatus for computing the rate of change of energy of an aircraft

Signals representative of the acceleration of an aircraft due to the change in flight path angle are coupled through a high pass filter (washout circuit) to obtain a short term compensation signal (V.sub.comp) which signal is further coupled to a low pass filter which provides short term integration to obtain the compansation signal (.DELTA. V.sub.comp) representative of change in speed in response to change in flight path angle. These compensation signals (V.sub.comp) and (.DELTA. V.sub.comp) are summed respectively with signals representative of longitudinal acceleration (or thrust control damping) and air speed error (or thrust control reference) to inhibit short term thrust control of the aircraft due to small flight path angle perturbations thereby improving the manual path control handling quality and the stability of the aircraft by the automatic control system. A modification of the system is disclosed for avoiding sensor noise developed by the .alpha. (angle of attack) vane sensor by utilization of other inputs to the system signal processing.

Thrust and flight path control decoupling system

A system for processing signals representative of airspeed error and inertial longitudinal acceleration of an aircraft to provide an output signal representative of windshear induced acceleration which is filtered to remove the high frequency components and which may be utilized to indicate the presence of windshear to a pilot who can then respond by resetting the thrust to maintain airspeed, or alternatively the output signal is utilized to correct the inertial damping signal of an airspeed control system under windshear conditions.

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Issaquah, WA, United States of America

Antonius A Lambregts