Aircraft self-adaptive anti-skid brake control method with runway / tire combination characteristic identification and pressure optimization function
By introducing a runway combination characteristic identification and pressure optimization module into the aircraft anti-skid braking system, the problem of poor runway adaptability in the existing technology is solved, achieving efficient and safe braking control, avoiding wheel slippage, and improving the system's anti-skid efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XIAN AVIATION BRAKE TECH
- Filing Date
- 2026-03-23
- Publication Date
- 2026-05-08
AI Technical Summary
Existing aircraft anti-skid braking systems struggle to accurately assess runway/tire engagement characteristics under complex and variable runway conditions, leading to brake pressure fluctuations, frequent wheel slippage, and low efficiency. Furthermore, current advanced algorithms require a large amount of data and additional status signals, failing to achieve efficient and smooth braking quickly.
The system employs a runway combination characteristic identification module, a brake control and pressure optimization module, and a wheel anti-lock braking control module. By estimating the runway combination characteristic level in real time, it optimizes the brake pressure based on the estimation results to avoid wheel slippage and outputs the maximum allowable brake pressure, thereby achieving efficient short-distance braking.
Without adding hardware, it achieves superior anti-skid braking performance, improves the engineering application value and safety of the system, and enables efficient and smooth braking under various runway conditions.
Smart Images
Figure CN121990157A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of aircraft anti-skid braking control technology, specifically to an adaptive anti-skid braking control method for aircraft with runway / tire engagement characteristic identification and pressure optimization functions. Background Technology
[0002] Aircraft anti-skid braking systems (ABS) operate during takeoff and landing, aiming to quickly, stably, and safely stop the aircraft by fully utilizing the maximum engagement torque provided by the runway. However, ABS is a complex, highly uncertain, nonlinear system. The runway / tire engagement characteristics are uncertain, difficult to measure, and highly variable, and the actuators of the ABS contain numerous nonlinear and uncertain factors. This presents challenges to the design of ABS control strategies, such as unclear control objectives and the actual braking torque output of the ABS falling short of control expectations, thus limiting the full utilization of the maximum engagement torque provided by the runway. The key to advanced ABS control strategy design lies in accurately assessing the current runway / tire engagement characteristics, accommodating the complex dynamic characteristics of the system output, and outputting an acceptable maximum braking pressure that matches the peak runway / tire engagement torque, thereby achieving efficient, short-distance, and smooth braking of the aircraft.
[0003] Currently, the aircraft anti-skid braking control method based on "speed difference + pressure bias adjustment" is widely used in domestic engineering practice. This method employs pressure bias adjustment, adjusting the control strategy based on the wheel motion state. It reduces braking pressure when the wheels slip and increases braking pressure when the wheels exit the slipping state. Under this anti-skid braking control method, when the aircraft brakes in scenarios with poor engagement characteristics, the braking pressure fluctuates continuously, and the wheels repeatedly perform the slip-and-exit action. This results in low overall efficiency of the anti-skid braking system and may even induce landing gear vibration. Furthermore, this method generally has fixed control parameters; the sensitivity and output amplitude of the anti-skid control remain unchanged under different runway conditions and operating conditions, making it unsuitable for the complex and variable runways and operating conditions during aircraft braking. The "speed difference + pressure bias adjustment" based anti-skid braking control method struggles to find and output the maximum acceptable braking pressure for the current scenario and operating conditions.
[0004] To address the shortcomings of widely used aircraft anti-skid braking control methods, many novel runway / tire engagement characteristic estimation methods and adaptive brake pressure adjustment strategies have been proposed. In runway / tire engagement characteristic estimation, nonlinear state observers based on wheel dynamics models are a common approach. However, this method often relies on sufficient runway excitation conditions, is prone to getting trapped in local optima, has slow convergence speed, and places high demands on the computational power of the anti-skid brake controller. These limitations make it inconsistent with the operational goals of anti-skid braking systems: rapid, accurate, and smooth braking of aircraft. In adaptive brake pressure adjustment, cutting-edge research applies advanced algorithms and theories such as machine learning and nonlinear model predictive control to design adaptive control laws that are compatible with external uncertainties, internal nonlinearities, and time-varying parameters, achieving the control objective of outputting an acceptable maximum brake pressure and fully utilizing the runway / tire engagement torque. However, these advanced algorithms require a large amount of data as a design basis and additional state signals for implementation; currently, their maturity is not high enough to meet the practical conditions for engineering applications.
[0005] To meet the new demands of advanced aircraft for anti-skid braking systems, and to develop an adaptive anti-skid braking control method that can be quickly put into engineering applications, a method with runway combination characteristic identification and pressure optimization is urgently needed to achieve short-distance and smooth braking under complex and variable runway conditions. Summary of the Invention
[0006] To overcome the shortcomings of the aforementioned background technology, this invention provides an aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization functions. It aims to solve the practical problems of poor runway adaptability and low anti-skid efficiency in existing aircraft anti-skid braking systems. This method utilizes a runway engagement characteristic identification module, a brake control and pressure optimization module, and a wheel anti-lock braking control module, among others. These modules cooperate and coordinate their actions to estimate the runway engagement characteristic level under various runway conditions and operating conditions. Based on the runway engagement characteristic estimation results, the braking pressure is optimized to output the maximum allowable braking pressure under the current runway and operating conditions while avoiding frequent wheel slippage, thus achieving efficient short-distance braking.
[0007] The first objective of this invention is to provide an adaptive anti-skid braking control method for aircraft with runway / tire engagement characteristic identification and pressure optimization functions, comprising: The pilot presses the brake pedal to issue a braking command; Determine the desired braking pressure based on the braking command; The current runway engagement characteristics level are estimated in real time based on the wheel motion state and braking pressure. Based on the current estimated runway combination characteristics, update the base braking pressure and control parameters; among which, the control parameters include the proportional gain of the boost function, the proportional gain of the depressurization function, the reference speed deceleration rate, the proportional stage gain, the micro-stage gain, and the pressure bias adjustment stage gain. Based on the updated baseline braking pressure and control parameters, find the maximum acceptable braking pressure to obtain the optimal pressure; Compare the expected braking pressure with the optimal pressure, and take the smaller value as the braking pressure command. Determine whether the wheel is slipping based on the wheel speed and reference speed; When the wheel slips, the anti-slip amount is calculated based on the control parameters and the anti-slip command is obtained. Then, the output brake pressure is obtained by subtracting the brake pressure command from the anti-slip command. When the wheels do not slip, the anti-slip command is zero, and the brake pressure command is used as the output brake pressure.
[0008] In one embodiment, the runway integration characteristics are divided into three categories: excellent, medium, and poor. Excellent corresponds to runway types with an integration coefficient of 0.6-0.9, medium corresponds to runway types with an integration coefficient of 0.3-0.6, and poor corresponds to runway types with an integration coefficient of less than 0.3.
[0009] In one embodiment, the runway integration characteristics are initialized to excellent; if the aircraft wheels slip once, the runway is downgraded by one level. When the wheels are not slipping and the brake pressure is greater than the threshold value P s2 When the current runway's combined characteristics reach the medium level, the runway rating is upgraded to medium. When the wheels are not slipping and the brake pressure is greater than the threshold value P s1 When the current runway characteristics reach "excellent", the runway rating is upgraded to "excellent". in, P s2 =800Psi, P s1 =1200Psi.
[0010] In one embodiment, determining whether the wheel's motion state is slipping based on the wheel speed includes: The reference speed is obtained based on the wheel speed, the initial value of the reference speed, and the reference speed deceleration rate. Based on the speed difference between the reference speed and the wheel speed Determine whether the wheel's motion is slipping; when Determine if the wheels are slipping; when At that time, it was assumed that the wheels were not slipping; in, The speed difference between the reference speed and the wheel speed; For reference speed; The set slip coefficient.
[0011] In one embodiment, the anti-slip amount is calculated based on control parameters, and an anti-slip command is obtained. P ant ,include: P ant = P antP + P antD + P antI in, P antP The anti-slip amount is calculated based on the proportional gain. P antD The anti-slip amount is calculated using the micro-gradient gain. P antI The anti-slip amount is calculated for the gain of the pressure bias adjustment stage.
[0012] In one embodiment, based on the updated baseline braking pressure and control parameters, the maximum acceptable braking pressure is determined to obtain the optimal pressure, including: The base braking pressure is used as the initial pressure after the runway bonding characteristics level is updated. Then, the braking pressure is adjusted according to the wheel motion state according to the pressure increase and decrease function until the maximum braking pressure that the runway can accept is found. When the runway combination characteristics are updated, the initial optimization pressure is the updated base braking pressure. The optimization pressure in the next control cycle is adjusted according to the wheel motion state, either increasing or decreasing the pressure, and so on, until the optimization pressure corresponding to the current runway is found.
[0013] In one embodiment, when operating according to the boost function, the boost amount in each control cycle is:
[0014] When operating according to the voltage reduction function, the voltage reduction in each control cycle is:
[0015] In the formula, To control the cycle; The speed difference between the reference speed and the wheel speed; For reference speed; The set slip coefficient; , These are the boost gain and buck gain, respectively.
[0016] The second objective of this invention is to provide a computer program product, including a computer program that, when executed by a processor, implements an aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization functions.
[0017] A third objective of this invention is to provide an electronic device comprising: Processor; and Memory for storing the executable instructions of the processor; The processor is configured to execute an aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization functions by executing the executable instructions.
[0018] A fourth objective of this invention is to provide a system for an aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization functions, comprising: Anti-slip brake controller, used by the pilot to issue a braking command by pressing the brake pedal; and to determine the desired braking pressure based on the braking command; The runway integration characteristics identification module is used to estimate the current runway integration characteristics level in real time based on the wheel motion state and brake pressure. The control parameter update module is used to update the base braking pressure and control parameters based on the currently estimated runway combination characteristic level. The control parameters include the proportional gain of the boost function, the proportional gain of the depressurization function, the reference speed deceleration rate, the proportional stage gain, the micro-stage gain, and the pressure bias adjustment stage gain. The brake control and pressure optimization module is used to find the maximum acceptable brake pressure based on the updated base brake pressure and control parameters, and obtain the optimized pressure; it compares the desired brake pressure with the optimized pressure, and takes the smaller value as the brake pressure command. The anti-lock braking control module is used to determine whether the wheel is slipping based on the wheel speed and a reference speed. When the wheel slips, the anti-slip amount is calculated according to the control parameters and an anti-slip command is obtained. Then, the output brake pressure is obtained by subtracting the brake pressure command from the anti-slip command. When the wheel does not slip, the anti-slip command is zero and the brake pressure command is used as the output brake pressure.
[0019] The present invention has at least the following beneficial effects: This invention provides an adaptive anti-skid braking control method for aircraft with runway / tire engagement characteristic identification and pressure optimization functions. This method utilizes only the existing hardware and state signals of the aircraft's anti-skid braking system to achieve functions such as runway engagement characteristic level estimation, pressure optimization based on the current runway engagement characteristic level, and adaptive anti-skid control. This invention achieves superior anti-skid braking performance without introducing additional hardware, possessing high engineering application value and low implementation cost. Furthermore, relying on existing, maturely transmitted state signals to implement the control logic enhances safety. In summary, this invention has high engineering application value, strong safety, and superior anti-skid braking performance. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the principle of the adaptive anti-skid braking control method for aircraft provided by the present invention; Figure 2 Flowchart of the aircraft adaptive anti-skid braking control method provided by the present invention; Figure 3 This is the curve showing the relationship between the desired braking pressure and the braking command. Figure 4 The results are from tests conducted under typical dry runway conditions: (a) aircraft speed and wheel speed, and (b) pressure efficiency calculation. Figure 5 The results are from tests conducted under typical wet runway conditions: (a) aircraft speed and wheel speed, and (b) pressure efficiency calculation. Figure 6 The results are from tests conducted under typical icy runway conditions. (a) Aircraft speed and wheel speed, (b) Pressure efficiency calculation. Detailed Implementation
[0021] To illustrate the technical means and effects adopted by the present invention in order to achieve the intended purpose, the following detailed description is provided in conjunction with embodiments.
[0022] This invention is mainly aimed at addressing the fact that the algorithms used in existing aircraft anti-skid braking control require a large amount of data as a design basis and additional state signals to be implemented. Currently, their maturity is not high enough and they do not yet meet the practical conditions for engineering application.
[0023] The purpose of this invention is to provide an adaptive anti-skid braking control method for aircraft with runway / tire engagement characteristic identification and pressure optimization functions. This method estimates the runway engagement characteristic level under various runway conditions and operating conditions, optimizes the braking pressure based on the runway engagement characteristic estimation results, and outputs the maximum allowable braking pressure under the current runway and operating conditions while avoiding frequent wheel slippage, thus achieving efficient short-distance braking.
[0024] See Figure 1As shown, the overall architecture of the aircraft adaptive anti-skid braking control method provided by the present invention includes a runway combination characteristic identification module, a brake control and pressure optimization module, a wheel anti-lock control module, and an anti-skid brake controller. Each module cooperates and coordinates with each other to estimate the runway combination characteristic level under various runway conditions and operating conditions, optimize the brake pressure based on the runway combination characteristic estimation results, and output the maximum allowable brake pressure under the current runway and operating conditions while avoiding frequent wheel slippage, thereby achieving efficient short-distance braking.
[0025] To achieve the above objectives, see Figure 2 As shown, an adaptive anti-skid braking control method for aircraft with runway / tire engagement characteristic identification and pressure optimization functions includes: S1. The pilot presses the brake pedal to issue a braking command; the desired braking pressure is determined based on the braking command. In this embodiment, the anti-slip brake controller starts working after receiving a braking command and determines the desired pressure based on the braking command. P d ; S2. Estimate the current runway engagement characteristics in real time based on the wheel motion state and braking pressure; Runway integration characteristics are classified into three categories: excellent, medium, and poor. Excellent corresponds to runway types with an integration coefficient of 0.6-0.9, medium corresponds to runway types with an integration coefficient of 0.3-0.6, and poor corresponds to runway types with an integration coefficient of less than 0.3.
[0026] If the runway's performance is initially set to excellent, and the runway degrades by one level for each instance of wheel slippage. When the wheels are not slipping and the brake pressure is greater than the threshold value P s2 When the current runway's combined characteristics reach the medium level, the runway rating is upgraded to medium. When the wheels are not slipping and the brake pressure is greater than the threshold value P s1 When the current runway characteristics reach "excellent", the runway rating is upgraded to "excellent". in, P s2 =800Psi, P s1 =1200Psi.
[0027] In this embodiment, after receiving the braking command, the runway integration characteristic identification module works, initializes the runway integration characteristic state to "excellent", and evaluates the current runway integration characteristic level in real time based on the wheel motion state and braking pressure during the braking process. S3. Update the base braking pressure and control parameters based on the current estimated runway combination characteristics level; among which, the control parameters include the proportional gain of the boost function, the proportional gain of the depressurization function, the reference speed deceleration rate, the proportional stage gain, the micro-stage gain, and the pressure bias adjustment stage gain. In this embodiment, the base braking pressure is updated based on the runway condition. P 0 and control parameters; S4. Based on the updated basic braking pressure and control parameters, find the maximum acceptable braking pressure to obtain the optimal pressure; compare the expected braking pressure and the optimal pressure, and take the smaller value as the braking pressure command. Based on the updated baseline braking pressure and control parameters, the maximum acceptable braking pressure is determined to obtain the optimal pressure, including: The base braking pressure is used as the initial pressure after the runway bonding characteristics level is updated. Then, the braking pressure is adjusted according to the wheel motion state according to the pressure increase and decrease function until the maximum braking pressure that the runway can accept is found. When the runway combination characteristics are updated, the initial optimization pressure is the updated base braking pressure. The optimization pressure in the next control cycle is adjusted according to the wheel motion state, either increasing or decreasing the pressure, and so on, until the optimization pressure corresponding to the current runway is found.
[0028] When operating according to the boost function, the boost amount in each control cycle is:
[0029] When operating according to the voltage reduction function, the voltage reduction in each control cycle is:
[0030] In the formula, To control the cycle; The speed difference between the reference speed and the wheel speed; For reference speed; The set slip coefficient; , These are the boost gain and buck gain, respectively.
[0031] In this embodiment, the brake control and pressure optimization module finds the acceptable maximum brake pressure based on the basic brake pressure and control parameters determined in S3, and obtains the optimized pressure. P opt And compare the expected braking pressure. P d With the pressure of seeking excellence P opt The smaller of the two values is taken as the braking pressure command. P com ; S5. Determine whether the wheel's motion state is slipping based on the wheel speed and reference speed; When the wheel slips, the anti-slip amount is calculated based on the control parameters and the anti-slip command is obtained. Then, the output brake pressure is obtained by subtracting the brake pressure command from the anti-slip command. When the wheels do not slip, the anti-slip command is zero, and the brake pressure command is used as the output brake pressure.
[0032] Determining whether the wheel is slipping based on wheel speed includes: The reference speed is obtained based on the wheel speed, the initial value of the reference speed, and the reference speed deceleration rate. Based on the speed difference between the reference speed and the wheel speed Determine whether the wheel's motion is slipping; when Determine if the wheels are slipping; when At that time, it was assumed that the wheels were not slipping; in, The speed difference between the reference speed and the wheel speed; For reference speed; The set slip coefficient.
[0033] The anti-slip amount is calculated based on the control parameters, and the anti-slip command is obtained. P ant ,include: P ant = P antP + P antD + P antI in, P antP The anti-slip amount is calculated based on the proportional gain. P antD The anti-slip amount is calculated using the micro-gradient gain. P antI The anti-slip amount is calculated for the gain of the pressure bias adjustment stage.
[0034] In this embodiment, the anti-lock braking control module selects whether to output an anti-slip command based on the wheel's motion state. When the wheel slips, the anti-lock braking control module operates, calculates the anti-slip amount based on the control parameters determined in S3, and outputs an anti-slip command; when the wheel does not slip, no anti-slip command is output. To further illustrate the aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization functions provided by the present invention, it is described in conjunction with the accompanying drawings.
[0035] An adaptive anti-skid braking control method for aircraft with runway / tire engagement characteristic identification and pressure optimization functions includes: Step 1: The pilot presses the brake pedal to issue a braking command, and the desired braking pressure is determined based on the braking command. P d The magnitude. The correspondence between expected braking pressure and braking command is as follows: Figure 3 As shown.
[0036] Step 2: Upon receiving the braking command, the runway engagement characteristic identification module activates, estimating the current runway engagement characteristic level in real time based on the wheel motion state and braking pressure. This module categorizes runway engagement characteristics into three levels: excellent, medium, and poor. Excellent corresponds to runway types with an engagement coefficient of 0.6-0.9, medium to runway types with an engagement coefficient of 0.3-0.6, and poor to runway types with an engagement coefficient below 0.3.
[0037] The runway integration characteristics module initializes the runway integration characteristics to excellent. If the aircraft wheels slip once, the runway will be downgraded by one level (excellent → medium or medium → poor).
[0038] When the wheel does not slip, and the brake pressure is greater than the threshold value of 2, that is... P b > P s2 When the runway's current runway characteristics are considered to be at a medium level, the runway rating is upgraded to medium; when the wheels are not slipping and the braking pressure is greater than the threshold value of 1, the runway rating is upgraded to medium. P b > P s1 At that time, the current runway's characteristics were considered excellent, and the runway rating was upgraded to excellent. In this implementation example, P s2 =800Psi, P s1 =1200Psi.
[0039] Step 3: Based on the runway combination characteristic estimation results in Step 2, update the control parameters in the brake control and pressure optimization module and the anti-lock braking control module in real time. This mainly includes the basic brake pressure in the brake control and pressure optimization module. P 0. Proportional gain of boost function k 1. Proportional gain of the step-down function k 2, Reference speed reduction rate in wheel anti-lock braking control module a r Scale-order gain K P Micro-level gain KD Pressure bias adjustment stage gain K I1 , K I2 , K I3 The control parameters corresponding to the estimation results of different runway combination characteristics are shown in Table 1 below.
[0040] Table 1. Control parameters corresponding to the estimation results of different runway combination characteristics.
[0041] Step 4: Under the combined effect of the base braking pressure and the pressure increase / decrease functions, the braking control and pressure optimization module finds the optimal pressure corresponding to the current runway state. P opt Specifically, when the runway condition assessment results are updated, the initial optimization pressure... P ot_0 = P 0. The optimization pressure for the next control cycle is selected to increase or decrease based on the wheel's motion state. P opt_1 = P opt_0 + or P opt_1 = P opt_0 + This process continues until the optimization pressure corresponding to the current runway is found. P opt ; Compare expected braking pressure P d With the pressure of seeking excellence P opt The smaller of the two values is taken as the braking pressure command. P com ; The braking control and pressure optimization module finds the maximum acceptable braking pressure for the current runway characteristics based on the base braking pressure and the designed pressure increase and decrease functions. Specifically, the base braking pressure... P 0 is used as the initial pressure after the runway condition assessment results are updated. Then, the braking pressure is adjusted according to the wheel motion state using pressure increase and decrease functions until the maximum acceptable braking pressure for the runway is found. Specifically, when operating according to the pressure increase function, the pressure increase amount in each control cycle is... , In the formula, To control the cycle.
[0042] When operating according to the voltage reduction function, the voltage reduction in each control cycle is:
[0043] In the formula, To control the cycle; The speed difference between the reference speed and the wheel speed; For reference speed; The set slip coefficient; , These are the boost gain and buck gain, respectively.
[0044] Step 5: The anti-lock braking system (ABS) module determines the wheel's motion state based on its speed. The ABS module is designed with a reference speed, specifically: .
[0045] In the formula, For reference speed, As a reference initial velocity value, For the speed of the wheel, For reference speed deceleration rate, t For time.
[0046] Based on reference speed and wheel speed generation speed difference Specifically: .
[0047] by As a criterion for determining whether the wheels are slipping, when Determine if the wheels are slipping; when At that time, it was assumed that the wheels were not slipping. The slip coefficient is set in this embodiment example. .
[0048] When it is determined that the wheels are not slipping, the anti-lock braking control module does not output an anti-slip command; the anti-slip command is zero, and the brake pressure command is applied. P com As output braking pressure; When wheel slippage is detected, the anti-lock braking control module outputs an anti-slip command. P ant It consists of the calculation results of the proportional stage, the micro stage, and the pressure bias adjustment stage, i.e. P ant = P antP + P antD + P antI , P antP、P antD 、P antI The anti-slip amounts are calculated for the proportional stage, the micro-stage, and the pressure bias adjustment stage, respectively. The anti-slip amount output by the proportional stage is: , The anti-slip amount output by the micro-grading is: , The anti-slip amount output by the pressure bias adjustment stage is: , In the formula, .
[0049] Finally, the brake pressure command will be sent. P com and anti-slip instructions P ant By subtracting the values, the output braking pressure can be obtained, i.e. P = P com - P ant .
[0050] Based on the above implementation examples, laboratory ground tests were conducted to obtain test results under three typical runway conditions: dry, wet, and icy. (See also...) Figure 4 , Figure 5 , Figure 6 As shown, the anti-skid braking control method of this invention can find the acceptable maximum braking pressure without skidding under dry track conditions, with a braking efficiency of up to 92.3% calculated based on braking pressure; under wet track conditions, only a few skids occur at low speeds, with a braking efficiency of up to 89.3%; and under the harsh conditions of icy track conditions, it can also find the acceptable maximum braking pressure with a limited number of skids, with an efficiency of up to 89.7%. The test results demonstrate the advanced nature of this invention.
[0051] This invention provides a computer program product, including a computer program that, when executed by a processor, implements an aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization functions.
[0052] This invention provides an electronic device, comprising: Processor; and Memory for storing the executable instructions of the processor; The processor is configured to execute an aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization functions by executing the executable instructions.
[0053] This invention provides a system for an aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization functions, comprising: Anti-slip brake controller, used by the pilot to issue a braking command by pressing the brake pedal; and to determine the desired braking pressure based on the braking command; The runway integration characteristics identification module is used to estimate the current runway integration characteristics level in real time based on the wheel motion state and brake pressure. The control parameter update module is used to update the base braking pressure and control parameters based on the currently estimated runway combination characteristic level. The control parameters include the proportional gain of the boost function, the proportional gain of the depressurization function, the reference speed deceleration rate, the proportional stage gain, the micro-stage gain, and the pressure bias adjustment stage gain. The brake control and pressure optimization module is used to find the maximum acceptable brake pressure based on the updated base brake pressure and control parameters, and obtain the optimized pressure; it compares the desired brake pressure with the optimized pressure, and takes the smaller value as the brake pressure command. The anti-lock braking control module is used to determine whether the wheel is slipping based on the wheel speed and a reference speed. When the wheel slips, the anti-slip amount is calculated according to the control parameters and an anti-slip command is obtained. Then, the output brake pressure is obtained by subtracting the brake pressure command from the anti-slip command. When the wheel does not slip, the anti-slip command is zero and the brake pressure command is used as the output brake pressure.
[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the principles of the present invention should be included within the protection scope of the present invention.
Claims
1. An adaptive anti-skid braking control method for aircraft with runway / tire engagement characteristic identification and pressure optimization functions, characterized in that, include: The pilot presses the brake pedal to issue a braking command; Determine the desired braking pressure based on the braking command; The current runway engagement characteristics level are estimated in real time based on the wheel motion state and braking pressure. Based on the current estimated runway combination characteristics, update the base braking pressure and control parameters; among which, the control parameters include the proportional gain of the boost function, the proportional gain of the depressurization function, the reference speed deceleration rate, the proportional stage gain, the micro-stage gain, and the pressure bias adjustment stage gain. Based on the updated baseline braking pressure and control parameters, find the maximum acceptable braking pressure to obtain the optimal pressure; Compare the expected braking pressure with the optimal pressure, and take the smaller value as the braking pressure command. Determine whether the wheel is slipping based on the wheel speed and reference speed; When the wheel slips, the anti-slip amount is calculated based on the control parameters and the anti-slip command is obtained. Then, the output brake pressure is obtained by subtracting the brake pressure command from the anti-slip command. When the wheels do not slip, the anti-slip command is zero, and the brake pressure command is used as the output brake pressure.
2. The aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization function according to claim 1, characterized in that, Runway integration characteristics are classified into three categories: excellent, medium, and poor. Excellent corresponds to runway types with an integration coefficient of 0.6-0.9, medium corresponds to runway types with an integration coefficient of 0.3-0.6, and poor corresponds to runway types with an integration coefficient of less than 0.
3.
3. The aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization function according to claim 2, characterized in that, If the runway's performance is initially set to excellent, and the runway degrades by one level for each instance of wheel slippage. When the wheels are not slipping and the brake pressure is greater than the threshold value P s2 When the current runway's combined characteristics reach the medium level, the runway rating is upgraded to medium. When the wheels are not slipping and the brake pressure is greater than the threshold value P s1 When the current runway characteristics reach "excellent", the runway rating is upgraded to "excellent". in, P s2 =800Psi, P s1 =1200Psi.
4. The aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization function according to claim 1, characterized in that, Determining whether the wheel is slipping based on wheel speed includes: The reference speed is obtained based on the wheel speed, the initial value of the reference speed, and the reference speed deceleration rate. Based on the speed difference between the reference speed and the wheel speed Determine whether the wheel's motion is slipping; when Determine if the wheels are slipping; when At that time, it was assumed that the wheels were not slipping; in, The speed difference between the reference speed and the wheel speed; For reference speed; The set slip coefficient.
5. The aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization function according to claim 1, characterized in that, Calculate the anti-slip amount based on the control parameters and obtain the anti-slip command. P ant , include: P ant = P antP + P antD + P antI in, P antP The anti-slip amount is calculated based on the proportional gain. P antD The anti-slip amount is calculated using the micro-gradient gain. P antI The anti-slip amount is calculated for the gain of the pressure bias adjustment stage.
6. The aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization function according to claim 1, characterized in that, Based on the updated baseline braking pressure and control parameters, the maximum acceptable braking pressure is determined to obtain the optimal pressure, including: The base braking pressure is used as the initial pressure after the runway bonding characteristics level is updated. Then, the braking pressure is adjusted according to the wheel motion state according to the pressure increase and decrease function until the maximum braking pressure that the runway can accept is found. When the runway combination characteristics are updated, the initial optimization pressure is the updated base braking pressure. The optimization pressure in the next control cycle is adjusted according to the wheel motion state, either increasing or decreasing the pressure, and so on, until the optimization pressure corresponding to the current runway is found.
7. The aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization function according to claim 6, characterized in that, When operating according to the boost function, the boost amount in each control cycle is: When operating according to the voltage reduction function, the voltage reduction in each control cycle is: In the formula, To control the cycle; The speed difference between the reference speed and the wheel speed; For reference speed; The set slip coefficient; , These are the boost gain and buck gain, respectively.
8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization function as described in any one of claims 1 to 7.
9. An electronic device, characterized in that, include: processor; as well as Memory for storing the executable instructions of the processor; The processor is configured to execute the aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization function as described in any one of claims 1 to 7 by executing the executable instructions.
10. A system for the aircraft adaptive anti-skid braking control method with runway / tire engagement characteristic identification and pressure optimization function as described in claim 1, characterized in that, include: Anti-slip brake controller, used by the pilot to issue braking commands by pressing the brake pedal; And determine the desired braking pressure based on the braking command; The runway integration characteristics identification module is used to estimate the current runway integration characteristics level in real time based on the wheel motion state and brake pressure. The control parameter update module is used to update the base braking pressure and control parameters based on the currently estimated runway combination characteristic level. The control parameters include the proportional gain of the boost function, the proportional gain of the depressurization function, the reference speed deceleration rate, the proportional stage gain, the micro-stage gain, and the pressure bias adjustment stage gain. The brake control and pressure optimization module is used to find the maximum acceptable brake pressure based on the updated base brake pressure and control parameters, and obtain the optimized pressure; it compares the desired brake pressure with the optimized pressure, and takes the smaller value as the brake pressure command. The anti-lock braking control module is used to determine whether the wheel is slipping based on the wheel speed and a reference speed. When the wheel slips, the anti-slip amount is calculated according to the control parameters and an anti-slip command is obtained. Then, the output brake pressure is obtained by subtracting the brake pressure command from the anti-slip command. When the wheel does not slip, the anti-slip command is zero and the brake pressure command is used as the output brake pressure.