A method for controlling air-ground signals of an aircraft brake system

Abstract

A kind of airplane brake system air-ground signal control method, through air-ground signal control circuit, determine magnetic latching relay, determine airplane ground signal, determine airplane air signal and determine airplane air-ground control logic realize the control of airplane brake system air-ground signal, the original airplane brake system electrical control system landing gear system landing switch and landing gear is retracted to position switch respectively increase magnetic latching relay in this application, the ground state of airplane is determined by landing gear system landing switch and magnetic latching relay, the air state of airplane is determined by landing gear is retracted to position switch and magnetic latching relay, completely solve the problem of unstable and unreliable airplane air / ground signal due to landing gear system landing switch simultaneously determining the air / ground state of airplane during airplane landing phase due to landing gear system landing switch repeatedly disconnecting and connecting, improve the safety of airplane brake system.

Description

Technical Field

[0001] This invention relates to the field of aircraft braking technology, and in particular to an air-to-ground signal control method for an aircraft braking system. Background Technology

[0002] The General Specification for Aircraft Wheel Anti-skid Braking Control Systems (GJB2879A-2008) describes the grounding protection function as follows: Before the aircraft touches down, or even if it has touched down but the main landing gear has not yet fully rotated, the anti-skid braking system should be able to prevent the application of braking pressure to the landing gear. The introduction of grounding protection should not affect the basic function of the anti-skid braking system.

[0003] Domestically produced third- and fourth-generation aircraft commonly employ electromagnetic, electronic, and digital fly-by-wire anti-skid braking systems. These systems are gradually incorporating landing gear-mounted floor switches or nose wheel-mounted switches to provide grounding protection. These floor switches or nose wheel-mounted switches are mechanical contact switches. The aircraft's air or ground status is determined by the force applied to the landing gear, which changes the state of the mechanical contact switches—for example, the air contact is closed, and the ground contact is open. This switch signal, indicating the change in air / ground status, is introduced into the aircraft's anti-skid braking system controller to achieve grounding protection. Aircraft with grounding protection can use the brake pedals in the air. If grounding protection fails, braking is initiated immediately upon landing, resulting in better efficiency, shorter braking distance, and improved runway adaptability. Specifically... Figure 1 Schematic diagram of the air / ground signal electrical system of an aircraft braking system. Figure 1 In the diagram, 1 is a +28V DC power supply, 2 is a floor switch, 3 is an anti-slip brake controller, and 4 is the power ground.

[0004] Due to various factors such as the aircraft's landing condition and changes in its center of gravity, the landing gear load changes during the ground taxiing and braking process. This alters the force state of the mechanical contact switches, causing the air-to-ground signal provided by the landing switches to be unstable and unreliable. In some cases, the anti-skid braking system has to disable its grounding protection function, reducing the aircraft's ergonomics and increasing braking distance. In extreme cases, if the landing switch contacts abnormally connect on the ground, the anti-skid brake controller may receive the abnormal landing switch signal and release the braking pressure, causing the aircraft to lose braking function during braking.

[0005] A search revealed that invention CN 104494815A discloses a method for landing protection of an aircraft anti-skid braking system, including determining the system state, determining the aircraft landing state, and determining whether to initialize the aircraft landing state. By determining and initializing the aircraft landing state, various in-flight and ground states of the aircraft can be comprehensively covered, enabling landing protection in the air and anti-skid braking on the ground, forming a closed-loop control for landing protection. This invention improves the reliability of landing protection for aircraft anti-skid braking systems and achieves landing protection for aircraft with continuous in-flight power supply. However, this invention does not solve the problem of unreliable air / ground signals in the braking system.

[0006] A search revealed an invention with publication number CN 10S000173A: an aircraft brake grounding protection system and method. This system includes a brake command sensor, a brake electronic control unit, left / right brake control valves, left / right main landing gear wheel speed sensors and wheel-mounted sensors, and an aircraft inertial navigation system. This invention ensures that during landing, if the pilot accidentally applies the brakes, the system does not generate brake pressure, keeping the brakes in a released state. When the aircraft wheel-mounted signal malfunctions, it prevents the aircraft from entering a brake grounding protection state at low speeds, ensuring the aircraft can still use the brakes at low speeds and improving landing safety. However, this invention does not address the problem of unreliable air / ground signals in the brake system. A search revealed an invention with publication number CN 105523177A: an aircraft brake grounding protection system. The system includes a brake controller, a brake control valve, wheel speed sensors, and wheel-mounted sensors. This invention ensures that during landing, if the pilot accidentally applies the brakes, the system will not output braking pressure, preventing the system from braking while landing and causing tire blowouts due to dragging, thus improving landing safety. However, this invention does not address the problem of unreliable air / ground signals in the braking system.

[0007] A search revealed that the invention with announcement number CN105620455A determines the aircraft's high / low speed status signal through logical operations of the low-speed detection unit in the anti-skid control box. The anti-skid control box collects the wheel speed signals of the left and right main landing gear wheels, processes and converts them, and uses them as a reference speed voltage signal to simulate the aircraft's speed. The low-speed detection unit of the anti-skid control box then provides the aircraft's high / low speed status. This invention ensures that the aircraft is in the air when it takes off again after landing, solving the problem of the grounding protection functioning only once. When the aircraft is on the ground, it is in a ground state, and its air / ground status is "1"; when the pilot depresses the brake pedal, the braking system outputs braking pressure to stop the aircraft; this solves the problem of brake failure caused by the grounding protection functioning at low speeds after landing. However, this invention does not solve the problem of unreliable air / ground signals in the braking system. Summary of the Invention

[0008] The purpose of this invention is to propose an air-to-ground signal control method for aircraft braking systems, which addresses the problems in existing technologies where unstable and unreliable air-to-ground signals provided by the landing switch cause loss of braking function during aircraft braking, as well as reduced human-machine interface efficiency and longer braking distances.

[0009] To achieve the above objectives, the following technical solution is adopted: a method for controlling air-to-ground signals of an aircraft braking system, comprising the following steps:

[0010] Step 1: Determine the air-to-ground signal control circuit, which includes a +28V DC power supply, a landing switch, an anti-skid brake controller, a power ground, a magnetic latching relay J1 coil, a magnetic latching relay J2 coil, and a landing gear retraction and positioning switch;

[0011] The +28V DC power supply is connected to the power input terminal of the anti-skid brake controller;

[0012] The +28V DC power supply is connected to the power input terminal of the floor switch; the power output terminal of the floor switch is connected to the positive terminal of the magnetic latching relay J1 coil; the negative terminal of the magnetic latching relay J1 coil is connected to the power ground.

[0013] The +28V DC power supply 1 is connected to the power input terminal of the landing gear retraction position switch; the power output terminal of the landing gear retraction position switch is connected to the positive terminal of the magnetic latching relay J2 coil; the negative terminal of the magnetic latching relay J2 coil is connected to the power ground.

[0014] The positive terminal of the magnetic latching relay is connected to the ground signal input terminal of the anti-skid brake controller;

[0015] The negative terminal of the magnetic latching relay is connected to the ground wire of the anti-skid brake controller.

[0016] Step 2: Determine the magnetic latching relay

[0017] A dual-coil, dual-contact, normally closed electromagnetic latching relay is selected as the automatic control element for air-to-ground signals in the aircraft braking system. The dual coils consist of two sets, J1 and J2. Coil J1 is the reset coil, and coil J2 is the set coil. The electromagnetic latching relay is powered by DC pulses or capacitor pulses to achieve contact switching. After contact switching, the armature inside the relay is held by a permanent magnet, and the contacts are in a holding state.

[0018] Step 3: Determine the aircraft ground status control logic

[0019] After the main landing gear wheel of the aircraft touches the ground, the landing gear system's landing switch is disconnected, the aircraft is in a ground state, the coil of the magnetic latching relay J1 is energized, and the magnetic latching relay contacts are set to open.

[0020] Step 4: Determine the aircraft's airborne signal

[0021] After takeoff, the landing gear retracts, the landing gear retraction position switch is activated, and the aircraft is in the air. The coil of the magnetic latching relay J2 is energized, the magnetic latching relay contacts are reset and closed, and the magnetic latching relay contacts return to the holding state.

[0022] Step 5: Determine the aircraft air-to-ground control logic

[0023] After the landing gear is retracted into position, the landing gear retraction switch is activated, and the aircraft is in the air. The landing gear retraction switch controls the coil of the magnetic latching relay J2 to be energized, the contacts of the magnetic latching relay are closed, and the magnetic latching relay is in the reset state. The magnetic latching relay transmits the air state to the anti-skid brake controller, and the anti-skid brake controller switches the control logic to the air state.

[0024] After the aircraft's main wheels touch down, the aircraft is in a ground state. The landing switch controls the coil of the magnetic latching relay J1 to be energized, the magnetic latching relay contacts open, and the magnetic latching relay is in the set state. The magnetic latching relay transmits the ground state to the anti-skid brake controller, and the anti-skid brake controller switches the control logic to the ground state.

[0025] Preferably, the rated voltage of the magnetic latching relay is determined, the contact actuation or reset voltage is determined, and the contact actuation or reset time is determined.

[0026] Preferably, a magnetic latching relay with a DC voltage of 36V is selected, which meets the aircraft's +28V DC power supply requirement;

[0027] The DC pulse signal required for the state transition of the magnetic latching relay is in the millisecond range. The landing switch signal output by the landing gear system's landing switch and the landing gear retraction switch signal output by the landing gear retraction position switch are continuous DC voltage signals. Therefore, the landing switch signal and the landing gear retraction position switch signal of the aircraft landing gear system can drive the magnetic latching relay to complete the state transition.

[0028] The normal operating voltage for a magnetic latching relay is no greater than 24V DC, and the maximum value is no greater than 32V DC.

[0029] Preferably, a dual-coil single-contact or dual-contact magnetic latching relay with model number JMX-3M RG4.520.137-9 is selected.

[0030] The beneficial effects achieved by this invention are as follows:

[0031] This invention provides an air-to-ground signal control method for an aircraft braking system. It adds magnetic latching relays to the landing gear system's landing gear landing switch and landing gear retraction position switch in the original aircraft braking system's electrical control system. The landing gear system's landing switch and magnetic latching relay determine the aircraft's ground status, while the landing gear retraction position switch and magnetic latching relay determine the aircraft's air status. This completely solves the problem of unstable and unreliable air-to-ground signals during landing caused by the repeated opening and closing of the landing gear system's landing gear system's landing switch, which was previously used to simultaneously determine the aircraft's air / ground status. This improves the safety of the aircraft braking system. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of an existing technology circuit.

[0033] Figure 2 This is a schematic diagram of the air-to-ground signal control circuit for the aircraft braking system of the present invention. Detailed Implementation

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0035] An air-to-ground signal control circuit for an aircraft braking system includes a +28V DC power supply 1, a ground switch 2, an anti-skid brake controller 3, a power ground 4, a magnetic latching relay J1 coil 5, a magnetic latching relay J2 coil 6, and a landing gear retraction position switch 7.

[0036] The +28V DC power supply 1 is connected to the power input terminal of the anti-skid brake controller 3;

[0037] +28V DC power supply 1 is connected to the power input terminal of floor switch 2; the power output terminal of floor switch 2 is connected to the positive terminal of the magnetic latching relay J1 coil; the negative terminal of the magnetic latching relay J1 coil is connected to the power ground.

[0038] The +28V DC power supply 1 is connected to the power input terminal of the landing gear retraction position switch 7; the power output terminal of the landing gear retraction position switch 7 is connected to the positive terminal of the magnetic latching relay J2 coil; the negative terminal of the magnetic latching relay J2 coil is connected to the power ground.

[0039] The positive terminal of the magnetic latching relay is connected to the ground signal input terminal of the anti-skid brake controller 3;

[0040] The negative terminal of the magnetic latching relay is connected to the ground wire of the anti-skid brake controller.

[0041] After the landing gear retracts into position during takeoff, the landing gear retraction switch is activated, the magnetic latching relay coil J2 is energized, and the magnetic latching relay contacts are reset and closed, putting the aircraft in the air. After landing, the landing switch is in the normally closed state, the magnetic latching relay coil J1 is energized, and the magnetic latching relay contacts are set and opened, putting the aircraft on the ground.

[0042] The present invention also includes an air-to-ground signal control method for an aircraft braking system. Through the aforementioned air-to-ground signal control circuit, the control of the air-to-ground signal of the aircraft braking system is achieved by determining the magnetic latching relay, determining the aircraft ground signal, determining the aircraft air signal, and determining the aircraft air-to-ground control logic. The specific steps are as follows.

[0043] Step 1: Determine the magnetic latching relay

[0044] A magnetic latching relay is an automatic switch. Normally, the open and closed states of its contacts are held in place by the magnetic force generated by a permanent magnet. This embodiment selects a dual-coil, dual-contact normally closed electromagnetic latching relay as the automatic control element for air-to-ground signals in the aircraft braking system. The dual coils consist of two sets, J1 and J2, with coil J1 being the reset coil and coil J2 being the set coil. The magnetic latching relay is powered by a DC pulse or a capacitor pulse to achieve contact switching. After contact switching, the armature inside the relay is held by the permanent magnet, and the contacts remain in the holding state.

[0045] This embodiment determines the pulse width of the DC pulse or capacitor pulse supply to the dual-coil single-contact or dual-contact magnetic latching relay; determines the rated voltage; determines the contact actuation or reset voltage; and determines the contact actuation or reset time.

[0046] 1) Select a magnetic latching relay with a DC voltage of 36V.DC, which meets the aircraft's power supply requirement of +28V.DC.

[0047] 2) The DC pulse signal required for the state transition of the magnetic latching relay is in the millisecond range. The landing switch signal output by the landing switch of the aircraft landing gear system and the landing gear retraction switch signal output by the landing gear retraction position switch are continuous DC voltage signals. Therefore, the landing switch signal and the landing gear retraction position switch signal of the aircraft landing gear system can drive the magnetic latching relay to complete the state transition.

[0048] 3) The normal operating voltage for the magnetic latching relay is no more than 24V DC, and the maximum value is no more than 32V DC.

[0049] In this embodiment, a dual-coil single-contact or dual-contact magnetic latching relay with model number JMX-3M RG4.520.137-9 is selected. Its rated voltage is 36V.DC, and the normal operating or reset voltage is no more than 24V.DC, with a maximum value of no more than 32V.DC.

[0050] Step 2: Determine the aircraft ground status control logic

[0051] After the main landing gear wheel of the aircraft touches the ground, the landing gear system's landing switch is disconnected, the aircraft is in a ground state, the coil of the magnetic latching relay J1 is energized, and the magnetic latching relay contacts are set to open.

[0052] In this embodiment, after the aircraft's main landing gear lands, the coil of the magnetic latching relay J1 is energized, causing the magnetic latching relay contacts to open.

[0053] Step 3: Determine the aircraft's airborne signal

[0054] After takeoff, the landing gear retracts, the landing gear retraction position switch is activated, and the aircraft is in the air. The magnetic latching relay coil J2 is energized, the magnetic latching relay contacts are reset and closed, and the magnetic latching relay contacts return to the holding state.

[0055] Step 4: Determine the aircraft air-to-ground control logic

[0056] The air-to-ground signal for the aircraft braking system consists of the landing gear system landing switch, the landing gear retraction position switch, and the magnetic latching relay.

[0057] After the landing gear is retracted into position, the landing gear retraction switch is activated, and the aircraft is in the air. The landing gear retraction switch controls the coil of the magnetic latching relay J2 to be energized, the contacts of the magnetic latching relay are closed, and the magnetic latching relay is in the reset state. The magnetic latching relay transmits the air state to the anti-skid brake controller, and the anti-skid brake controller switches the control logic to the air state.

[0058] After the main wheels of the aircraft touch down, the aircraft is in a ground state. The landing switch controls the coil of the magnetic latching relay J1 to be energized, the contacts of the magnetic latching relay open, and the magnetic latching relay is in the set state. The magnetic latching relay transmits the ground state to the anti-skid brake controller, and the anti-skid brake controller switches the control logic to the ground state.

[0059] This completes a method for controlling air-to-ground signals in an aircraft braking system.

[0060] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for controlling air-to-ground signals of an aircraft braking system, characterized in that: Includes the following steps: Step 1: Determine the air-to-ground signal control circuit, which includes a +28V DC power supply, a landing switch, an anti-skid brake controller, a power ground, a magnetic latching relay J1 coil, a magnetic latching relay J2 coil, and a landing gear retraction position switch; The +28V DC power supply is connected to the power input terminal of the anti-skid brake controller; The +28V DC power supply is connected to the power input terminal of the floor switch; the power output terminal of the floor switch is connected to the positive terminal of the magnetic latching relay J1 coil; the negative terminal of the magnetic latching relay J1 coil is connected to the power ground. The +28V DC power supply (1) is connected to the power input terminal of the landing gear retraction position switch; the power output terminal of the landing gear retraction position switch is connected to the positive terminal of the magnetic latching relay J2 coil; the negative terminal of the magnetic latching relay J2 coil is connected to the power ground. The positive terminal of the magnetic latching relay is connected to the ground signal input terminal of the anti-skid brake controller; The negative terminal of the magnetic latching relay is connected to the ground wire of the anti-skid brake controller; Step 2: Determine the magnetic latching relay A dual-coil, dual-contact, normally closed electromagnetic latching relay is selected as the automatic control element for air-to-ground signals in the aircraft braking system. The dual coils consist of two sets, J1 and J2. Coil J1 is the reset coil, and coil J2 is the set coil. The electromagnetic latching relay is powered by DC pulses or capacitor pulses to achieve contact switching. After the contact switching, the armature inside the relay is held by a permanent magnet, and the contact is in a holding state. Step 3: Determine the aircraft ground status control logic After the main landing gear wheel of the aircraft touches the ground, the landing gear system's landing switch is disconnected, the aircraft is in a ground state, the coil of the magnetic latching relay J1 is energized, and the contacts of the magnetic latching relay are set to open. Step 4: Determine the aircraft's airborne signal After takeoff, the landing gear retracts, the landing gear retraction switch is activated, and the aircraft is in the air. The coil of the magnetic latching relay J2 is energized, the magnetic latching relay contacts are reset and closed, and the magnetic latching relay contacts return to the holding state. Step 5: Determine the aircraft air-to-ground control logic After the landing gear is retracted into position, the landing gear retraction switch is activated, and the aircraft is in the air. The landing gear retraction switch controls the coil of the magnetic latching relay J1 to be energized, the contacts of the magnetic latching relay are closed, and the magnetic latching relay is in the reset state. The magnetic latching relay transmits the air state to the anti-skid brake controller, and the anti-skid brake controller switches the control logic to the air state. After the main wheels of the aircraft touch down, the aircraft is in a ground state. The landing switch controls the coil of the magnetic latching relay J2, the contacts of the magnetic latching relay open, and the magnetic latching relay is in the set state. The magnetic latching relay transmits the ground state to the anti-skid brake controller, and the anti-skid brake controller switches the control logic to the ground state.

2. The air-to-ground signal control method for an aircraft braking system according to claim 1, characterized in that: Determine the rated voltage of the magnetic latching relay, determine the contact actuation or reset voltage, and determine the contact actuation or reset time.

3. The air-to-ground signal control method for an aircraft braking system according to claim 2, characterized in that: A magnetic latching relay with a DC voltage of 36V was selected, which meets the aircraft's +28V DC power supply requirement. The DC pulse signal required for the state transition of the magnetic latching relay is in the millisecond range. The landing switch signal output by the landing gear system's landing switch and the landing gear retraction switch signal output by the landing gear retraction position switch are continuous DC voltage signals. Therefore, the landing switch signal and the landing gear retraction position switch signal of the aircraft landing gear system can drive the magnetic latching relay to complete the state transition. The normal operating voltage for a magnetic latching relay is no greater than 24V DC, and the maximum value is no greater than 32V DC.

4. The air-to-ground signal control method for an aircraft braking system according to claim 1 or 3, characterized in that: Select a dual-coil single-contact or dual-contact magnetic latching relay with model number JMX-3M RG4.520.137-9.

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