CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application No. 201710641540.1 filed on Jul. 31, 2017, which is incorporated herein by reference in its entirety.

FIELD

This disclosure relates to an aircraft, and more particularly to a flap slat control lever of the aircraft.

BACKGROUND

A high-lift system of a modern large aircraft includes slats positioned at a leading edge of a wing and flaps positioned at a trailing edge of the wing. During a low speed stage such as take-off, landing, or the like, the slats at the leading edge and/or the flaps at the trailing edge can extend outward and/or bend downward to increase the wing area, thereby changing the configuration and providing lift for the aircraft. This makes sure that the aircraft has a reasonable taxiing distance and a safe take-off speed, while improving the climb rate, the approach speed and the approach attitude, etc.

A flap slat control lever (or Flap/Slat Control Lever, FSCL) is a control part of the high-lift system for controlling the extension and retraction of the flaps and slats. The FSCL is usually mounted on a central console for operation by a pilot.FIG. 1illustrates a perspective view of a traditional FSCL, which includes for example a handle101, a light guide plate102with position marks, a housing103, a locking element104, a pull rod105with a force-sensitive device, a spring assembly106, a plunger107, a locking pin108, a sector gear109, an engagement member110, a pinion shaft111, slots for engagement112, a planetary gear train connected with the pull rod, and a four-way RVDT sensor (not shown), and the like. In operation, the pilot needs to lift the handle101first, and then move the handle101to actuate the pull rod105to move along a guide rail (usually in the form of a groove). During this process, the force-sensitive device of the pull rod105generates a lifting force and a friction force which hinder the movement. At the same time, the pull rod105actuates the planetary gear train to rotate so as to drive the RVDT sensor, which generates a pull rod displacement signal to be transmitted to a slat/flap control computer (SFCC). The SFCC can control the operation of the flaps and slats according to the pull rod displacement signal.

Although the function of the FSCL is simple, with the ever growing of the safety level and complexity of the aircraft system, the requirement on its availability has been increasing as well. The design requirement for failure probability of the high-lift system for an earlier single-channel aircraft is smaller than or equal to 1E-6. Thus, an FSCL with a traditional architecture can meet the system's requirement on its availability. The design requirement for failure probability of the high-lift system for a later large dual-channel aircraft is smaller than or equal to 1E-9. Such requirement is thus allocated to the lever from top to bottom, requiring that the failure probability of the lever should be smaller than or equal to 1E-9. A lever with a traditional architecture has a failure probability far from achieving the level of being smaller than 1E-9.

In addition, the comfort of operating the FSCL is also difficult to control. The lever has certain lifting force and friction force. The lifting force locks the lever within a corresponding slot. When the lever is to be moved, it is necessary to overcome the lifting force, so as to move the lever along the guide rail. When the lever is moved along the guide rail, it will generate a friction force. The friction force provides perceptibility for the pilot in the process of moving the lever. The design of the lifting force and the friction force should meet the human-machine efficacy and function needs. If the forces are too large, it will impose a burden on the pilot; otherwise if the forces are too small, it will be difficult for the lever to slide into the slot. If the friction force is too small, there will be no obvious feeling during the operation, and it may cause misoperation.

The disclosure intends to solve a technical problem of providing an improved flap slat control lever.

SUMMARY OF THE INVENTION

This disclosure provides an improved flap slat control lever.

According to one embodiment of this disclosure, a flap slat control lever comprises: a first displacement sensor to detect a displacement of the flap slat control lever and generate a first displacement detection signal; a second displacement sensor to detect the displacement of the flap slat control lever and generate a second displacement detection signal; a first control command module to receive the first displacement detection signal from the first displacement sensor; and a second control command module to receive the second displacement detection signal from the second displacement sensor, wherein the first control command module is in a standby state and the second control command module is in a working state, the first control command module sends the first displacement detection signal to the second control command module, wherein the second control command module compares the first displacement detection signal with the second displacement detection signal, and if a difference between the first displacement detection signal and the second displacement detection signal is within an error tolerance, sends the first displacement detection signal or the second displacement detection signal to a slat/flap control computer as a control signal to control operation of flaps and slats.

In one aspect, the second control command module sends either one, a larger one or a smaller one of the first displacement detection signal and the second displacement detection signal to the slat/flap control computer as the control signal to control the operation of the flaps and slats.

In one aspect, if the first control command module is in failure, the first control command module will not send the first displacement detection signal to the second control command module, and the second control command module sends the second displacement detection signal to the slat/flap control computer as the control signal to control the operation of the flaps and slats; or if the second control command module is in failure, the second control command module is switched to a deactivated state, and the first control command module is switched to a working state, wherein the first control command module sends the first displacement detection signal to the slat/flap control computer as the control signal to control the operation of the flaps and slats.

In one aspect, the first control command module and the second control command module verify whether the first displacement detection signal and the second displacement detection signal are within a preset range of values respectively, wherein the first control command module being in failure comprises the first control command module failing the verification of the first displacement detection signal, and wherein the second control command module being in failure comprises the second control command module failing the verification of the second displacement detection signal, or the second control command module determining that the difference between the first displacement detection signal and the second displacement detection signal is not within the error tolerance for a predetermined times.

In one aspect, the first control command module and the second control command module each comprises a monitor channel and receives the first displacement detection signal from the first displacement sensor and the second displacement detection signal from the second displacement sensor respectively via the monitor channels.

In one aspect, the flap slat control lever also comprises: a lifting force mechanism to generate a lifting force for the flap slat control lever; a friction force mechanism to generate a friction force during movement of the flap slat control lever, wherein the first control command module and the second control command module each comprises a control channel to control the lifting force of the lifting force mechanism and the friction force of the friction force mechanism when in the working state.

In one aspect, the flap slat control lever also comprises: a force sensor to sense a force applied on the flap slat control lever to generate a force signal; and a third control command module to receive the force signal, and if the force signal is above a preset threshold, send a valid discrete signal to the slat/flap control computer to extend the flaps and slats to a go-around configuration.

In one aspect, the slat/flap control computer operates according to the valid discrete signal from the third control command module when receiving both the control signal from the first control command module or the second control command module and the valid discrete signal from the third control command module.

In one aspect, the first displacement sensor and the second displacement sensor each comprises any one of a RVDT, a potentiometer, or a photoelectric encoder.

In one aspect, the photoelectric encoder comprises a grating plate and a photoelectric detection device, wherein the photoelectric encoder outputs three groups of square wave pulses with phase-A, phase-B and phase-Z respectively, wherein the two groups of pulses with phase-A and phase-B determine a motion direction of the lever, and the pulses with phase-Z determine a position of the lever.

According to another embodiment of this disclosure, a method for operating a flap slat control lever is provided, the method comprising: detecting a displacement of the flap slat control lever and generating a first displacement detection signal; detecting the displacement of the flap slat control lever and generating a second displacement detection signal; using a first control command module to receive the first displacement detection signal; and using a second control command module to receive the second displacement detection signal, wherein the first control command module is in a standby state and the second control command module is in a working state, the first control command module sends the first displacement detection signal to the second control command module, wherein the second control command module compares the first displacement detection signal with the second displacement detection signal, and if a difference between the first displacement detection signal and the second displacement detection signal is within an error tolerance, sends the first displacement detection signal or the second displacement detection signal to a slat/flap control computer as a control signal to control operation of flaps and slats.

In one aspect, the second control command module sends either one, a larger one or a smaller one of the first displacement detection signal and the second displacement detection signal to the slat/flap control computer as the control signal to control the operation of the flaps and slats.

In one aspect, if the first control command module is in failure, the first control command module will not send the first displacement detection signal to the second control command module, and the second control command module sends the second displacement detection signal to the slat/flap control computer as the control signal to control the operation of the flaps and slats; or if the second control command module is in failure, the second control command module is switched to a deactivated state, and the first control command module is switched to a working state, wherein the first control command module sends the first displacement detection signal to the slat/flap control computer as the control signal to control the operation of the flaps and slats.

In one aspect, the first control command module and the second control command module verify whether the first displacement detection signal and the second displacement detection signal are within a preset range of values respectively, wherein the first control command module being in failure comprises the first control command module failing the verification of the first displacement detection signal, and wherein the second control command module being in failure comprises the second control command module failing the verification of the second displacement detection signal, or the second control command module determining that the difference between the first displacement detection signal and the second displacement detection signal is not within the error tolerance for a predetermined times.

In one aspect, the method also comprises: controlling, by the first control command module or the second control command module in the working state and through a control channel, a lifting force and a friction force of the flap slat control lever.

In one aspect, the method also comprises: sensing a force applied on the flap slat control lever to generate a force signal; and using a third control command module to receive the force signal, and if the force signal is above a preset threshold, sending a valid discrete signal to the slat/flap control computer to extend the flaps and slats to a go-around configuration.

In one aspect, the method also comprises: operating, by the slat/flap control computer, according to the valid discrete signal from the third control command module when receiving both the control signal from the first control command module or the second control command module and the valid discrete signal from the third control command module.

The flap slat control lever of this disclosure employs multiple redundancy measures, and optionally has adjustable lifting force and friction force. The flap slat control lever includes a plurality of displacement sensors and a plurality of control command modules. Different combinations of these components ensure that the pilot can operate the FSCL under any predictable operation condition, so as to output a useful command signal to the high-lift system. Furthermore, the flap slat control lever can also adjust the lifting force and/or the friction force of the FSCL, so as to accommodate different system/operator requirements.

