Mechanism self-checking method of aircraft electric brake suitable for various actuating structures

Abstract

According to the mechanism self-checking method of the aircraft electric brake suitable for various actuation structures, the self-checking process of a self-checking state machine is reasonably designed, the change rate of a pressure sensor is used as a criterion, driving control logic is combined, power-on self-checking and mechanism self-checking in an all-electric brake system are completed, and the self-checking efficiency is improved. And stable zero searching of the brake mechanism to reach the pre-brake position is realized. The method is suitable for various disc type brake structures, caliper type brake structures and the like, the reliability is high, and the brake pressure head can still be driven to reach the pre-brake position under the conditions of carbon disc abrasion, brake device rigidity change, sensor zero drift, mechanism pre-brake force change and even different brake structures. The problem of under-pressure landing of an all-electric brake system is solved, an important component power-on detection method is provided, and accident signs in the aircraft landing process are eliminated.

Description

Technical Field

[0001] This invention relates to a mechanism self-testing method for aircraft electric brakes that are adaptable to various actuation structures, belonging to the technical field of all-electric braking systems. Background Technology

[0002] Aircraft braking systems need to withstand the dynamic impact loads during landing and absorb the kinetic energy of the aircraft during landing, enabling control of the aircraft's taxiing, turning, and landing. All-electric braking technology, due to its simple structure, high reliability, and good dynamic performance, is gradually replacing traditional hydraulic-electric brakes and is widely used in various types of aircraft.

[0003] Before a fully electric brake reaches ground, a self-check of the braking mechanism's internal health status is required to inform the control system's decisions. This self-check is a crucial step, involving two aspects: first, determining whether key components in the actuation mechanism are functioning correctly; and second, driving the brake pressure head to the pre-braking position to prevent the aircraft from landing with the brakes applied excessively. Currently, there are few patents related to the self-check logic of fully electric brakes; existing patents mainly concern the power-on self-check logic of electro-hydraulic transmissions.

[0004] Based on the existing patent literature, no solution has been provided for the self-testing of electronic components and mechanisms in all-electric brakes, and the risk of false alarms and failures in self-testing caused by sensor drift and failure has not been taken into account. Summary of the Invention

[0005] The technical problem to be solved by this invention is: in order to overcome the shortcomings of the prior art, and to address the problems of force sensor drift, carbon disc wear leading to cumbersome adjustment of pre-brake pressure value and stop brake pressure value, a mechanism self-testing method for aircraft electric brakes that is adaptable to various actuation structures is provided. By rationally designing the mechanism self-testing process, the brake mechanism can stably find zero and reach the pre-brake position.

[0006] The technical solution adopted in this invention is: a mechanism self-testing method for aircraft electric brakes adaptable to various actuation structures, comprising: S1: Initialize variables, including brake mechanism self-test timing, self-test state machine status, pressure feedback value change rate, Hall position status variable, and fault status variable; shut down the power circuit and record the zero bias current value; initialize brake mechanism self-test timing; filter the AD acquisition value of brake pressure; proceed to S2. S2, detect the Hall signal and power supply of the brake mechanism and determine the self-test time of the brake mechanism. If the self-test time of the brake mechanism does not exceed the time limit, proceed to S3; if the self-test time of the brake mechanism exceeds the time limit, proceed to S7. S3, determine the stage of the self-test state machine. If the self-test state machine is in the positive pressure stage, proceed to S4; if the self-test state machine is in the brake release stage, proceed to S5; if the self-test state machine is in the self-test failure stage, proceed to S7; if the self-test state machine is in the self-test success stage, proceed to S6. S4, open-loop drive brake head forward propulsion, and calculate the rate of change of the filtered pressure feedback value, including: If the rate of change of the current pressure feedback value jumps beyond the set threshold, the pressure sensor is considered to be faulty, the fault status is recorded, the self-test state machine stage is changed to the self-test failure stage, and the process enters S7. If the rate of change of the current pressure feedback value does not exceed the set threshold, the force sensor state count is performed. If the rate of change of the pressure feedback value continues to be positive, the self-test state machine is changed to the brake release stage and enters S5. If the force sensor status count does not reach the set count value, continue with step S4; If the force sensor state count does not reach the set count value, but the self-test time count of the brake mechanism exceeds the time limit, it indicates that the force sensor is faulty. Change the self-test state machine stage to the self-test failure stage and enter S7. Simultaneously, the Hall position sensor is detected. If the Hall position sensor is faulty, the self-test state machine is changed to the self-test failure stage and enters S7. S5, use open-loop reverse propulsion to drive the brake head away from the brake disc, calculate the rate of change of the filtered pressure feedback value, and count the force sensor status until the detected force sensor pressure value enters the error band, record the current force sensor pressure value, update the current brake pressure value to zero, change the self-test state machine stage to the self-test success stage, and enter S6. If the force sensor state count does not reach the set count value, but the self-test time count of the brake mechanism exceeds the time limit, it indicates that the force sensor is faulty. Change the self-test state machine stage to the self-test failure stage and enter S7. Simultaneously, the Hall position sensor is detected. If the Hall position sensor is faulty, the self-test state machine is changed to the self-test failure stage and enters S7. S6, record the current pressure sensor value as the pre-brake zero value, record the current Hall position count value as the initial zero value; and update the self-test state machine stage to the self-test success stage, and feed back the information of the self-test state machine stage to the upper control system via the bus; S7 records the current fault status, distinguishing between motor Hall sensor faults, force sensor faults, and transmission mechanism faults. If it is a force sensor fault or a Hall sensor fault, it uses Hall fault-tolerant open-loop control to reverse the brake head away from the brake disc and counts until the counting timer is completed. The fault status is reported via the bus.

[0007] The advantages of this invention compared to the prior art are: 1. This invention uses the rate of change of pressure sensor as a criterion, combined with drive control logic, to complete the power-on self-test and mechanism self-test in the all-electric braking system. Compared with traditional methods, it can accurately locate the fault in the braking system and improve the test coverage of the braking system.

[0008] 2. This invention, by employing a scheme to monitor the rate of change of the pressure sensor, avoids the problems of pre-brake pressure value changes caused by pressure sensor drift and pre-brake position drift caused by carbon disc wear during long-term use. It can effectively ensure that the all-electric brake can reach the pre-brake position after the mechanism self-test is successful; if the self-test fails, the brake pressure head can be disengaged from the brake disc, eliminating the possibility of braking under pressure.

[0009] 3. In the self-testing logic of this invention, the state judgment and switching rely solely on pressure sensors, without relying on traditional Hall effect counting as a means of brake release. This greatly reduces the debugging work for designers in finding the pre-brake position and the stop brake pressure position. Moreover, the detection sensor is of a single source, relying only on pressure sensors, which can reliably adapt to different drive motors, brake devices of different stiffness, and different types of brake mechanisms such as disc and caliper brakes. Attached Figure Description

[0010] Figure 1 This is a flowchart of the self-test control method for the all-electric braking mechanism. Detailed Implementation

[0011] The present invention will be described in conjunction with the accompanying drawings.

[0012] This invention provides a power-on self-test process for a mechanism based on pressure sensor change rate monitoring. Through a rationally designed self-test process, it achieves stable zero-finding and pre-braking position of the braking mechanism. This method is adaptable to various disc and caliper brake structures, exhibiting high reliability. It can still drive the brake head to the "pre-braking position" even under conditions of carbon disc wear, changes in brake device rigidity, sensor zero-point drift, changes in pre-braking force, and even different brake structures. This invention eliminates the problem of pressurized landing in fully electric braking systems, provides a method for power-on detection of critical components, and eliminates accident symptoms during aircraft landing.

[0013] like Figure 1 As shown, the present invention provides a mechanism self-testing method for an aircraft electric brake adaptable to various actuation structures, comprising the following steps: Step 1: Initialize variables, including brake mechanism self-test timing, self-test state machine status, rate of change of pressure feedback value, Hall position status variable and fault status variable; shut down the power circuit and record the zero bias current value; initialize brake mechanism self-test timing; filter the AD acquisition value of brake pressure; proceed to Step 2. Step 2: Detect the Hall signal and +5V power supply of the brake mechanism and determine the self-test time of the brake mechanism. If the self-test time of the brake mechanism does not exceed the time limit, proceed to Step 3; if the self-test time of the brake mechanism exceeds the time limit, proceed to Step 7. Step 3: Determine the stage of the self-test state machine. If it is in the positive pressure stage, proceed to Step 4; if it is in the brake release stage, proceed to Step 5; if it is in the self-test failure stage, proceed to Step 7; if it is in the self-test success stage, proceed to Step 6. Step 4: Drive the brake pressure head forward in an open-loop manner and calculate the rate of change of the filtered pressure feedback value. If the rate of change of the current pressure feedback value jumps beyond the set threshold, the pressure sensor is considered faulty, the fault status is recorded, the self-test state machine stage is changed to the self-test failure stage, and the process proceeds to Step 7. If the rate of change of the current pressure feedback value does not jump beyond the set threshold, the force sensor status is counted. If the rate of change of the pressure feedback value remains positive, the self-test state machine stage is changed to the brake release stage, and the process proceeds to Step 5. If the force sensor status count does not reach the set count value, the process continues with Step 4. If the force sensor status count does not reach the count value, but the self-test timeout of the brake mechanism indicates a force sensor fault, the self-test state machine stage is changed to the self-test failure stage, and the process proceeds to Step 7. Simultaneously, the Hall position sensor is detected. If the Hall position sensor is faulty, the self-test state machine is changed to the self-test failure stage, and then proceeds to step seven. Step 5: Use open-loop reverse propulsion to drive the brake pressure head away from the brake disc, calculate the rate of change of the filtered pressure feedback value, and count the force sensor status until the detected force sensor pressure value enters the error band. Record the current force sensor pressure value and update the current brake pressure value to zero. Change the self-test state machine stage to the self-test success stage and proceed to Step 6. If the force sensor status count does not reach the count value, but the self-test time of the brake mechanism exceeds the count, it indicates that the force sensor is faulty. Change the self-test state machine stage to the self-test failure stage and proceed to Step 7. Simultaneously, the Hall position sensor is checked. If the Hall position sensor is faulty, the self-test state machine is changed to the self-test failure stage, and then proceeds to step seven.

[0014] Step 6: Record the current pressure sensor value as the pre-brake zero value and the current Hall position count value as the initial zero value; update the self-test state machine to the self-test success stage, and feed back the information of the self-test state machine stage to the upper control system via the bus. Step 7: Record the current fault status, distinguishing between motor Hall sensor fault, force sensor fault, and transmission mechanism fault. If it is a force sensor fault or Hall sensor fault, use Hall fault-tolerant open-loop control to reverse the brake head away from the brake disc and count the faults until the counting timer is complete. Report the fault status via the bus.

[0015] Table 1. Self-inspection and testing items of the organization

[0016] The parts of this invention not described in detail are well-known to those skilled in the art.

Claims

1. A self-testing method for the mechanism of an aircraft electric brake adaptable to various actuation structures, characterized in that, include: S1: Initialize variables, including brake mechanism self-test timing, self-test state machine status, pressure feedback value change rate, Hall position status variable, and fault status variable; shut down the power circuit and record the zero bias current value; initialize brake mechanism self-test timing; filter the AD acquisition value of brake pressure; proceed to S2. S2, detect the Hall signal and power supply of the brake mechanism and determine the self-test time of the brake mechanism. If the self-test time of the brake mechanism has not exceeded the time limit, proceed to S3. S3, determine the current stage of the self-test state machine, including: If the self-test state machine is in the positive pressure stage, then proceed to S4; If the self-test state machine is in the brake release stage, then proceed to S5; S4, open-loop drive brake head forward propulsion, and calculate the rate of change of the filtered pressure feedback value, including: If the rate of change of the current pressure feedback value does not exceed the set threshold, the force sensor state count is performed. If the rate of change of the pressure feedback value continues to be positive, the self-test state machine is changed to the brake release stage and enters S5. S5, use open-loop reverse propulsion to drive the brake head away from the brake disc, calculate the rate of change of the filtered pressure feedback value, and count the force sensor status until the detected force sensor pressure value enters the error band, record the current force sensor pressure value, update the current brake pressure value to zero, change the self-test state machine stage to the self-test success stage, and enter S6. S6, record the current pressure sensor value as the pre-brake zero value, record the current Hall position count value as the initial zero value; and update the self-test state machine stage to the self-test success stage, and feed back the information of the self-test state machine stage to the upper control system via the bus.

2. The self-testing method for an aircraft electric brake adaptable to multiple actuation structures according to claim 1, characterized in that, Also includes: S7 records the current fault status, distinguishes between motor Hall sensor fault, force sensor fault, and transmission mechanism fault. If it is a force sensor fault or Hall sensor fault, the Hall fault-tolerant open-loop control is used to reverse the brake head to drive away from the brake disc and counts until the counting timer is completed; the fault status is reported through the bus.

3. The self-testing method for an aircraft electric brake adaptable to multiple actuation structures according to claim 2, characterized in that, S2 further includes: If the self-check of the braking mechanism takes too long, proceed to step S7.

4. The self-testing method for an aircraft electric brake adaptable to multiple actuation structures according to claim 3, characterized in that, S3, determining the stage of the self-test state machine, further includes: If the self-test state machine is in the self-test failure stage, then proceed to S7; If the self-test state machine is in the self-test success phase, then proceed to S6.

5. A self-testing method for an aircraft electric brake adaptable to multiple actuation structures according to claim 4, characterized in that, S4, which involves open-loop driving the brake pressure head forward and calculating the rate of change of the filtered pressure feedback value, also includes: If the rate of change of the current pressure feedback value jumps beyond the set threshold, the pressure sensor is considered to be faulty, the fault status is recorded, the self-test state machine stage is changed to the self-test failure stage, and the process proceeds to S7.

6. The self-testing method for an aircraft electric brake adaptable to multiple actuation structures according to claim 5, characterized in that, S4, which involves open-loop driving the brake pressure head forward and calculating the rate of change of the filtered pressure feedback value, also includes: If the force sensor status count does not reach the set count value, continue with step S4.

7. A self-testing method for an aircraft electric brake adaptable to multiple actuation structures according to claim 6, characterized in that, S4, which involves open-loop driving the brake pressure head forward and calculating the rate of change of the filtered pressure feedback value, also includes: If the force sensor state count does not reach the set count value, but the self-test time count of the brake mechanism exceeds the time limit, it indicates that the force sensor is faulty. Change the self-test state machine stage to the self-test failure stage and enter S7.

8. A self-testing method for an aircraft electric brake mechanism adaptable to multiple actuation structures according to claim 7, characterized in that, In step S4, the Hall position sensor is detected simultaneously. If the Hall position sensor is faulty, the self-test state machine is changed to a self-test failure stage and proceeds to step S7.

9. A self-testing method for an aircraft electric brake adaptable to multiple actuation structures according to claim 8, characterized in that, The S5 also includes: If the force sensor state count does not reach the set count value, but the self-test time count of the brake mechanism exceeds the time limit, it indicates that the force sensor is faulty. Change the self-test state machine stage to the self-test failure stage and enter S7.

10. A mechanism self-testing method for an aircraft electric brake adaptable to multiple actuation structures according to claim 9, characterized in that, In step S5, the Hall position sensor is detected simultaneously. If the Hall position sensor is faulty, the self-test state machine is changed to a self-test failure stage and proceeds to step S7.

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