CN-121990157-A - Self-adaptive anti-skid brake control method for aircraft with runway/tire combination characteristic identification and pressure optimizing functions

CN121990157ACN 121990157 ACN121990157 ACN 121990157ACN-121990157-A

Abstract

The invention relates to the technical field of aircraft anti-skid brake control, in particular to an aircraft self-adaptive anti-skid brake control method with runway/tire combination characteristic identification and pressure optimizing functions, which comprises the steps of estimating the current runway combination characteristic level in real time according to the movement state of wheels and brake pressure; searching for the maximum brake pressure according to the updated basic brake pressure to obtain the optimizing pressure, comparing the expected brake pressure with the optimizing pressure, taking the minimum value of the expected brake pressure and the optimizing pressure as a brake pressure command, obtaining the output brake pressure according to the difference between the brake pressure command and the anti-skid command when the wheel slips, and taking the brake pressure command as the output brake pressure when the wheel does not slip. According to the invention, based on the braking pressure optimization of the runway combined characteristic estimation result, the maximum braking pressure allowed under the current runway and working condition is output on the premise of avoiding frequent skidding of the wheels, and the efficient short-distance braking is realized.

Inventors

ZHANG XIAOSHEN
CAO YONG
ZHANG XIA
YANG ZHIXIONG
CHEN JIALEI
CHEN GAIGE
Liang Juhan

Assignees

西安航空制动科技有限公司

Dates

Publication Date: 20260508
Application Date: 20260323

Claims (10)

1. An aircraft self-adaptive anti-skid brake control method with runway/tire combination characteristic identification and pressure optimizing functions is characterized by comprising the following steps: The pilot steps on the brake to give a brake instruction; determining an expected brake pressure according to the brake command; estimating the current runway combination characteristic level in real time according to the motion state of the wheels and the brake pressure; Updating basic brake pressure and control parameters according to the currently estimated runway combination characteristic level, wherein the control parameters comprise proportional gain of a boost function and proportional gain of a buck function, and reference speed deceleration rate, proportional gain, differential gain and pressure bias regulation gain; searching for the maximum brake pressure according to the updated basic brake pressure and the control parameters to obtain the optimizing pressure; comparing the expected braking pressure with the optimizing pressure, and taking small values of the expected braking pressure and the optimizing pressure as braking pressure instructions; judging whether the wheel movement state is a slip state or not based on the wheel speed and the reference speed; When the wheel slips, calculating the anti-slip quantity according to the control parameters, obtaining an anti-slip instruction, and then obtaining output brake pressure according to difference between the brake pressure instruction and the anti-slip instruction; when the wheel does not slip, the anti-slip instruction is zero, and the braking pressure instruction is taken as the output braking pressure.
2. The method for controlling an adaptive anti-skid brake of an aircraft with runway/tire combination characteristic identification and pressure optimizing functions according to claim 1, wherein the runway combination characteristic level is classified into three categories of excellent, medium and poor, wherein the excellent corresponds to a runway type with a runway combination coefficient of 0.6-0.9, the medium corresponds to a runway type with a runway combination coefficient of 0.3-0.6, and the poor corresponds to a runway type with a runway combination coefficient of 0.3 or less.
3. The method for controlling adaptive anti-skid braking of an aircraft with runway/tire combination characteristic identification and pressure optimizing functions according to claim 2, wherein the runway combination characteristic level is initialized to be optimal, the wheels skid once, and the runway falls one step; when the wheels are not slipped and the braking pressure is larger than the threshold value P s2 , the current runway combination characteristic is achieved, and the runway rating is upgraded to the middle; When the wheels are not slipped and the brake pressure is larger than the threshold value P s1 , the combination characteristic of the current runway is excellent, and the runway rating is improved to be excellent; Where P s2 =800Psi,P s1 = 1200Psi.
4. The method for adaptive anti-skid brake control of an aircraft having runway/tire combination characteristic identification and pressure optimizing functions according to claim 1, wherein determining whether the wheel movement state is a slip state based on the wheel speed comprises: Acquiring a reference speed according to the initial value of the wheel speed and the reference speed deceleration rate; According to the speed difference between the reference speed and the wheel speed Judging whether the motion state of the wheels is a slipping state or not; When (when) Judging the skidding state of the wheels; When (when) When the wheel is not slipped; Wherein, the Is the speed difference between the reference speed and the wheel speed; Is the reference speed; is the set slip coefficient.
5. The method for controlling adaptive anti-skid braking of an aircraft with runway/tire combination characteristic identification and pressure optimizing function according to claim 1, wherein calculating the amount of skid resistance according to the control parameter and obtaining the anti-skid command P ant comprises: P ant =P antP +P antD +P antI Wherein P antP is the anti-slip amount calculated by the proportional gain, P antD is the anti-slip amount calculated by the differential gain, and P antI is the anti-slip amount calculated by the pressure bias adjusting gain.
6. The method for adaptive anti-skid brake control of an aircraft with runway/tire combination characteristic identification and pressure optimizing function according to claim 1, wherein searching for a maximum brake pressure acceptable according to the updated basic brake pressure and control parameters to obtain the optimizing pressure comprises: Taking the basic brake pressure as the initial pressure after the runway combination characteristic level is updated, and then adjusting the brake pressure according to the wheel motion state and the boosting and reducing functions until the maximum brake pressure which can be accepted by the runway is found; When the runway is combined with the characteristic level to update, the initial optimizing pressure is the updated basic brake pressure, the optimizing pressure in the next control period is selected to be increased or decreased according to the motion state of the wheels, and the like until the optimizing pressure corresponding to the current runway is found.
7. The method for adaptive anti-skid brake control of an aircraft having runway/tire combination characteristic identification and pressure optimizing functions as set forth in claim 6, wherein the amount of boost in each control cycle when operating according to a boost function is: when working according to the step-down function, the step-down amount in each control period is as follows: in the formula, Is a control period; is the speed difference between the reference speed and the wheel speed; Is the reference speed; the slip coefficient is set; 、 The boost gain and the buck gain are respectively.
8. A computer program product comprising a computer program, characterized in that the computer program, when executed by a processor, implements the method for controlling adaptive anti-skid braking of an aircraft with runway/tyre combination characteristic identification and pressure optimizing functions according to any one of claims 1 to 7.
9. An electronic device, comprising: processor, and A memory for storing executable instructions of the processor; wherein the processor is configured to perform the aircraft adaptive anti-skid brake control method with runway/tire combination characteristic identification and pressure optimizing function of any one of claims 1 to 7 via execution of the executable instructions.
10. A system for the adaptive anti-skid brake control method for an aircraft having runway/tire combination characteristic identification and pressure optimizing functions of claim 1, comprising: The anti-skid brake controller is used for providing a brake instruction when a pilot steps on a brake, and determining expected brake pressure according to the brake instruction; the runway combination characteristic identification module is used for estimating the current runway combination characteristic level in real time according to the movement state of the wheels and the brake pressure; The control parameter updating module is used for updating basic brake pressure and control parameters according to the currently estimated runway combination characteristic level, wherein the control parameters comprise the proportional gain of a boosting function, the proportional gain of a depressurization function, a reference speed deceleration rate, the proportional gain, the differential gain and the pressure bias regulating gain; The brake control and pressure optimizing module is used for searching the maximum brake pressure according to the updated basic brake pressure and control parameters to obtain the optimizing pressure; The machine wheel anti-lock control module is used for judging whether the motion state of the machine wheel is a slip state or not based on the machine wheel speed and the reference speed, calculating the anti-slip quantity according to the control parameters when the machine wheel slips, obtaining an anti-slip instruction, then obtaining output brake pressure according to difference between the brake pressure instruction and the anti-slip instruction, and taking the brake pressure instruction as the output brake pressure when the machine wheel does not slip.

Description

Self-adaptive anti-skid brake control method for aircraft with runway/tire combination characteristic identification and pressure optimizing functions Technical Field The invention relates to the technical field of aircraft anti-skid brake control, in particular to an aircraft self-adaptive anti-skid brake control method with runway/tire combination characteristic identification and pressure optimizing functions. Background The anti-skid braking system works in the take-off, landing and running stage of the airplane, and aims to fully utilize the maximum combination moment provided by the runway to rapidly, stably and safely brake and stop the airplane. However, aircraft anti-skid braking systems are a complex, non-linear system with a high degree of uncertainty. The combination characteristics of the runway/tyre are uncertain, difficult to measure, complex and variable, and the non-linearity and uncertainty factors in the actuating mechanism of the anti-skid braking system are numerous. The design of the anti-skid braking control strategy of the aircraft brings challenges of unclear control targets, inferior actual output braking moment of the anti-skid braking system, control expectation and the like, and restricts the full utilization of the maximum combined moment provided by the anti-skid braking system of the aircraft on the runway. The key of the advanced anti-skid brake control strategy design is that the current runway/tire combination characteristic level is accurately estimated, the complex dynamics characteristic output of a compatible system is compatible, the acceptable maximum brake pressure matched with the peak value combination moment of the runway/tire is output, and the efficient, short-distance and stable brake of the aircraft is realized. At present, the aircraft anti-skid brake control method based on speed difference and pressure bias adjustment is widely applied to engineering practice in China. The method adopts a pressure bias adjustment method, adjusts a control strategy based on the movement state of the wheel, reduces the braking pressure when the wheel slips, and increases the braking pressure when the wheel exits from the slipping state. Under the action of the anti-skid brake control method, when the aircraft brakes under the scene of poor combination characteristics, the brake pressure can continuously fluctuate, the wheels continuously repeatedly skid and exit the skid action, the whole working efficiency of the anti-skid brake system is low, and the undercarriage vibration can be excited. In addition, the method generally has fixed control parameters, and under different runway conditions and running conditions, the sensitivity and the output amplitude of the anti-skid control are kept unchanged, so that the method cannot adapt to changeable complex runways and working conditions in the braking process of the aircraft. The anti-skid brake control method based on speed difference and pressure bias adjustment is difficult to find and output the maximum brake pressure acceptable in the current scene and working condition. Aiming at the defects of the anti-skid brake control method of the airplane with wide application, a plurality of novel runway/tire combination characteristic estimation methods and brake pressure self-adaptive adjustment strategies are proposed. In the context of runway/tire combination property estimation, nonlinear state observers based on the mechanical model of the wheel are common means. The method is often dependent on sufficient runway excitation conditions, is easy to sink into a local optimal solution, has low convergence speed and has high requirement on the calculation capability of the anti-skid brake controller. These limitations result in inconsistent with the goal of the anti-skid brake system to brake the aircraft quickly, accurately, and smoothly. In the aspect of self-adaptive regulation of brake pressure, advanced algorithms such as machine learning, nonlinear model predictive control and the like and theoretical design self-adaptive control laws are applied to the front-edge research so as to be compatible with external uncertainty, internal nonlinearity and parameter time variability of a system, and control targets of outputting acceptable maximum brake pressure and fully utilizing runway/tire combined moment are realized. However, these advanced algorithms require a large amount of data as a design basis, and require additional status signals to implement, so that the maturity is not high enough at present, and the actual conditions of engineering application are not met. In order to meet the new requirements of advanced airplanes on an anti-skid brake system, a self-adaptive anti-skid brake control method capable of being quickly put into engineering application is obtained, short-distance and stable braking is realized under complex and changeable runway conditions, and an airplane self-adaptive anti-skid brake control method with