A wheel cylinder pressure regulating method and system for a brake-by-wire system

Abstract

The application relates to a wheel cylinder pressure regulating method and system of a brake-by-wire system, which comprises the following steps: based on a pre-established dynamic model of a master cylinder pressure change of a motor servo hydraulic brake-by-wire system, estimating disturbances and uncertain parameters of the brake-by-wire system, obtaining master cylinder pressure control parameters based on the estimation results; designing a wheel cylinder pressure increase and decrease logic threshold control method and determining a wheel cylinder allowable pressure error upper limit; based on the determined wheel cylinder allowable pressure error upper limit, obtaining control parameters of a wheel cylinder pressure regulating on-off electromagnetic valve based on an adaptive neural network on-off electromagnetic valve control method; based on the obtained master cylinder pressure control parameters and the on-off electromagnetic valve control parameters, controlling the master cylinder pressure and the on-off electromagnetic valve of the brake-by-wire system, and realizing wheel cylinder pressure regulation of the brake-by-wire system. The application can be widely applied in the field of brake-by-wire systems.

Description

TECHNICAL FIELD

[0001] The application provides a wheel cylinder pressure regulating method and system of a brake-by-wire system, in particular a wheel cylinder pressure regulating method and system of a motor servo hydraulic brake-by-wire system for vehicles, and belongs to the technical field of brake-by-wire. BACKGROUND

[0002] Brake-by-wire is one of the basic functions required by vehicles with advanced driver assistance systems and future full automatic driving capabilities. In addition, vehicle stability functions such as anti-lock braking systems, traction control systems (TCS) and electronic stability control programs have been widely equipped in modern vehicles, and even become essential functions to improve vehicle safety. These functions all require two basic capabilities of the brake-by-wire system, namely active braking and independent wheel braking force regulation, to maximize the tire force of each wheel.

[0003] In the past two decades, two types of brake-by-wire systems have been developed, namely electronic hydraulic brake-by-wire systems and electronic mechanical brake-by-wire systems. Due to heat dissipation and reliability problems, electronic mechanical brake-by-wire systems are still at the prototype level, which makes electronic hydraulic brake-by-wire systems the only practical brake-by-wire system solution. There are two types of electronic hydraulic brake-by-wire systems currently equipped on vehicles, one is a pump-accumulator-based electronic hydraulic brake-by-wire system, and the other is a motor servo hydraulic brake-by-wire system.

[0004] An electronic hydraulic brake-by-wire system is composed of an active high-pressure source and a wheel pressure regulating module, and the main difference between a pump-accumulator-based electronic hydraulic brake-by-wire system and a motor servo hydraulic brake-by-wire system is the high-pressure source. The pump-accumulator-based electronic hydraulic brake-by-wire system uses a pump-driven accumulator as the high-pressure source, while the motor servo hydraulic brake-by-wire system uses a motor-driven supercharger as the high-pressure source. Thanks to the servo capability of the motor, the motor servo hydraulic brake-by-wire system has become the mainstream BBW (brake-by-wire) solution.

[0005] Independent regulation of the braking pressure of each wheel is a basic function of an electronic hydraulic brake-by-wire system and a basic requirement for realizing vehicle stability control functions. However, the motor servo hydraulic brake-by-wire system mainly relies on the motor to regulate the wheel cylinder pressure, and the master cylinder pressure control method cannot be coordinated with the wheel cylinder pressure regulating process, while the energy consumption is high and the regulation accuracy is limited. SUMMARY

[0006] To address the issue of wheel cylinder pressure regulation in motor-servo hydraulic brake-by-wire systems, the present invention aims to provide a method and system for regulating wheel cylinder pressure in brake-by-wire systems. By employing a pressure regulation method that coordinates the pressure of the master cylinder and the wheel cylinder, the present invention eliminates the role of the traditional pump motor in the wheel cylinder pressure regulation process of a brake-by-wire system for the first time, and has significant advantages such as high regulation accuracy and low energy consumption.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a method for adjusting wheel cylinder pressure in a brake-by-wire system, comprising the following steps:

[0009] Based on the pre-established dynamic model of the master cylinder pressure change of the motor servo hydraulic brake-by-wire system, the disturbance and uncertainty parameters of the brake-by-wire system are estimated, and the master cylinder pressure control parameters are obtained based on the estimation results.

[0010] A threshold control method for increasing and decreasing pressure in wheel cylinders is designed, and the upper limit of the allowable pressure error of wheel cylinders is determined.

[0011] Based on determining the upper limit of the allowable pressure error of the wheel cylinder, the control parameters of the wheel cylinder pressure regulating solenoid valve are calculated using an adaptive neural network switching solenoid valve control method.

[0012] Based on the obtained master cylinder pressure control parameters and solenoid valve control parameters, the master cylinder pressure and solenoid valve of the brake-by-wire system are controlled to achieve wheel cylinder pressure regulation of the brake-by-wire system.

[0013] Furthermore, based on the pre-established dynamic model of the master cylinder pressure change in the motor-servo hydraulic brake-by-wire system, the disturbance and uncertainty parameters of the brake-by-wire system are estimated, and the master cylinder pressure control parameters are obtained based on the estimation results, including:

[0014] A dynamic model of the pressure change in the master cylinder of a motor-servo hydraulic linear control system is established.

[0015] Based on the dynamic model of the pressure change in the master cylinder, a disturbance observer is designed to obtain the observed values ​​of the lumped disturbance of the master cylinder system.

[0016] Design an adaptive equation to estimate the uncertain parameter w, and obtain an estimate of the uncertain parameter w.

[0017] Based on the observed values ​​of the lumped disturbance of the master cylinder system, the estimated values ​​of the uncertain parameters, and the pre-designed master cylinder pressure controller, the master cylinder pressure control parameters are obtained.

[0018] Furthermore, the dynamic model of the master cylinder pressure change is expressed as follows:

[0019]

[0020] Where x1 represents the hydraulic pressure in the master cylinder, in MPa; x2 represents the rate of change of the master cylinder pressure, i.e., the derivative of the hydraulic pressure x1 in the master cylinder with respect to time, in MPa / s; ω represents the rotational speed of the servo motor, in rad / s; T f The equivalent frictional torque, expressed in Nm, is measured from the master cylinder system; w represents an uncertain parameter, expressed in MPa / (Nm·s). 2 ); u represents the current input of the servo motor, in amperes (A); k m This represents the torque gain of the servo motor, measured in Nm / A; A c The cross-sectional area of ​​the master cylinder piston is represented by the unit m. 2 G represents the reduction ratio from the rotation angle of the servo motor to the displacement of the master cylinder piston, in rad / m. Represents the lumped sum of other uncertain disturbances in the master cylinder system, in MPa / (s) 2 ); and These represent the first derivatives of x1 and x2 with respect to time, respectively.

[0021] Furthermore, based on determining the upper limit of the allowable pressure error of the wheel cylinder, the control parameters of the wheel cylinder pressure regulating solenoid valve are calculated using an adaptive neural network switching solenoid valve control method, including:

[0022] Based on the target wheel cylinder pressure p wd and cylinder pressure measurement p w Using a pre-designed guide controller, the first control parameter u is calculated. GC ;

[0023] Based on the target wheel cylinder pressure p wd and actual control output u v The second control parameter u is obtained by using a pre-designed inverse model controller. IMNC ;

[0024] According to the wheel cylinder pressure measurement p w The actual control output u of the system v and target wheel cylinder pressure p wd The third control parameter u is obtained by using a pre-designed system identification neural network and inner loop controller. SINC ;

[0025] Based on the first control parameter u GC Second control parameter u IMNC and the third control parameter u SINC The final control parameters of the switching solenoid valve are obtained.

[0026] Furthermore, the pressure p measured based on the wheel cylinder w The actual control output u of the system v and target wheel cylinder pressure p wd The third control parameter u is obtained by using a pre-designed system identification neural network and inner loop controller. SINC ,include:

[0027] According to the wheel cylinder pressure measurement p w and the actual control output u of the system v By utilizing a pre-designed system recognition neural network, the recognition pressure can be obtained.

[0028] Based on identification pressure and target wheel cylinder pressure p wd The third control parameter u is obtained by using a pre-designed inner loop controller. SINC .

[0029] Furthermore, the formula for calculating the final control parameters is as follows:

[0030] u v =u GC +u SINC +u IMNC

[0031] Among them, u GC The first control parameter to guide the output of the controller; u SINC To identify the second control parameter output by the controller; u IMNC This is the third control parameter output by the inverse model controller.

[0032] In a second aspect, the present invention provides a wheel cylinder pressure regulating system for a brake-by-wire system, comprising:

[0033] The master cylinder pressure control parameter acquisition module is used to estimate the disturbance and uncertainty parameters of the brake-by-wire system based on the pre-established dynamic model of the master cylinder pressure change of the motor servo hydraulic brake-by-wire system, and obtain the master cylinder pressure control parameters based on the estimation results.

[0034] The wheel cylinder pressure increase / decrease logic threshold control module is used to design the wheel cylinder pressure increase / decrease logic threshold control method and determine the upper limit of the wheel cylinder's allowable pressure error.

[0035] The solenoid valve control parameter acquisition module is used to calculate the control parameters of the wheel cylinder pressure regulating solenoid valve based on the adaptive neural network solenoid valve control method, based on the determination of the upper limit of the allowable pressure error of the wheel cylinder.

[0036] The wheel cylinder pressure regulation module is used to control the master cylinder pressure and the solenoid valve of the brake-by-wire system based on the obtained master cylinder pressure control parameters and the solenoid valve control parameters, thereby realizing the wheel cylinder pressure regulation of the brake-by-wire system.

[0037] Furthermore, the solenoid valve control parameter acquisition module is equipped with an adaptive neural network solenoid valve model, which includes a guide controller, an inverse model controller, an inner loop controller, a system identification network, and an output controller; the input of the guide controller is the target wheel cylinder pressure p. wd and cylinder pressure measurement p w The output is the first control parameter u. GC The input to the inverse model controller is the target wheel cylinder pressure p. wd and actual control output u v The output is the second control parameter u. IMNC The input to the inner loop controller is the target wheel cylinder pressure p. wd and the output of the system identification network The output is the third control parameter u. SINC The input to the system identification network is the wheel cylinder measured pressure p. w and the actual control output u of the system v The output is the identified pressure. The output controller is based on the first control parameter u GC Second control parameter u IMNC and the third control parameter u SINC The final control parameters of the can-opening solenoid valve are obtained.

[0038] Thirdly, the present invention provides a computer-readable storage medium for storing one or more programs, said one or more programs including instructions that, when executed by a computing device, cause the computing device to perform any of the methods.

[0039] Fourthly, the present invention provides a computing device comprising: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for performing any of the methods.

[0040] The present invention has the following advantages due to the adoption of the above technical solutions:

[0041] 1. This invention proposes a master cylinder pressure control method that takes into account the loss of master cylinder fluid caused by the adjustment process of the wheel cylinder solenoid valve. It solves the problem that the existing master cylinder pressure control method cannot be coordinated with the wheel cylinder pressure adjustment process, and realizes for the first time pump-free wheel cylinder pressure regulation of the motor servo hydraulic line control braking system.

[0042] 2. The electronic valve control method based on adaptive neural network in the wheel cylinder pressure regulation process of this invention avoids the complex valve body modeling process.

[0043] Therefore, this invention can be widely applied in the field of brake-by-wire technology. Attached Figure Description

[0044] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings:

[0045] Figure 1 This is a flowchart of the wheel cylinder pressure adjustment method for the brake-by-wire system provided in an embodiment of the present invention;

[0046] Figure 2 This is the main cylinder model of the motor servo hydraulic wire control braking system established in the embodiments of the present invention;

[0047] Figure 3 This is a flowchart of the wheel cylinder pressure regulation logic threshold control method for a motor servo-driven wire-controlled hydraulic braking system provided in an embodiment of the present invention;

[0048] Figure 4 This is a flowchart of the control method for the solenoid valve of the wheel cylinder pressure regulating function in a motor servo-driven wire-controlled hydraulic braking system provided in an embodiment of the present invention. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of 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, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0050] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0051] Some embodiments of the present invention provide a wheel cylinder pressure regulation method for a brake-by-wire system. This method mainly includes two aspects: First, addressing the changes in system parameters and external disturbances caused by brake fluid loss in the master cylinder during wheel cylinder pressure regulation in a motor-servo hydraulic brake-by-wire system, a master cylinder pressure control mechanism capable of simultaneously handling parameter changes and compensating for external disturbances is proposed, providing stable back pressure for solenoid valve-based wheel cylinder pressure regulation. Second, addressing the complexity of solenoid valve modeling during wheel cylinder pressure regulation, an adaptive neural network-based wheel cylinder pressure regulation mechanism is proposed. The wheel cylinder pressure regulation method for a brake-by-wire system provided by the present invention solves the problem that existing master cylinder pressure control methods cannot coordinate with the wheel cylinder pressure regulation process. Simultaneously, the electronic valve control method based on the adaptive neural network avoids the complex valve body modeling process during wheel cylinder pressure regulation.

[0052] Correspondingly, some other embodiments of the present invention provide a wheel cylinder pressure regulation system for a brake-by-wire system.

[0053] Example 1

[0054] like Figure 1 As shown, a method for adjusting wheel cylinder pressure in a brake-by-wire system provided in this embodiment is described, which includes the following steps:

[0055] 1) Based on the pre-established dynamic model of the master cylinder pressure change of the motor servo hydraulic wire control brake system, the disturbance and uncertainty parameters of the wire control brake system are estimated, and the master cylinder pressure control parameters, i.e. the current input value of the servo motor, are obtained based on the estimation results.

[0056] Specifically, it includes the following steps:

[0057] 1.1) Establish a dynamic model of the pressure change of the master cylinder in the motor servo hydraulic linear control system.

[0058] like Figure 2 The diagram shows the dynamic model of the master cylinder pressure change in the motor-servo hydraulic linear control system established in this embodiment. It includes a servo motor, a transmission mechanism, a master cylinder push rod, and a master cylinder connected in sequence. Under the control of the input torque, the servo motor drives the transmission mechanism to rotate. The rotation of the transmission mechanism causes the master cylinder push rod to move. The displacement of the master cylinder push rod causes the master cylinder piston, connected to the end of the push rod and located inside the master cylinder, to move, resulting in a change in the brake fluid pressure within the master cylinder.

[0059] based on Figure 1 The dynamic model of the master cylinder pressure change shown is as follows:

[0060]

[0061] Where x1 represents the hydraulic pressure in the master cylinder, in MPa; x2 represents the rate of change of the master cylinder pressure, i.e., the derivative of the hydraulic pressure x1 in the master cylinder with respect to time, in MPa / s; ω represents the rotational speed of the servo motor, in rad / s; T f The equivalent frictional torque, expressed in Nm, is measured from the master cylinder system; w represents an uncertain parameter, expressed in MPa / (Nm·s). 2 ); u represents the current input of the servo motor, in amperes (A); k m This represents the torque gain of the servo motor, measured in Nm / A; A c The cross-sectional area of ​​the master cylinder piston is represented by the unit m. 2 G represents the reduction ratio from the rotation angle of the servo motor to the displacement of the master cylinder piston, in rad / m. Represents the lumped sum of other uncertain disturbances in the master cylinder system, in MPa / (s) 2 ); and These represent the first derivatives of x1 and x2 with respect to time, respectively.

[0062] 1.2) Based on the dynamic model of the master cylinder pressure change, a disturbance observer is designed to obtain the lumped disturbance of the master cylinder system. The observed values.

[0063] The designed disturbance observer is as follows:

[0064]

[0065] in, This represents the observed value of the hydraulic pressure x1 in the main cylinder, in MPa; This represents the observed rate of change of pressure in the master cylinder, expressed in MPa / s. Representative of the aggregate of disturbances The observed values ​​are in MPa / (s) 2 ); and Represent and The first derivative with respect to time; Represents the estimated value of the uncertain parameter, in MPa / (Nm·s). 2 );ω o ψ represents a design parameter greater than 0, without units; ψ represents the regression factor in the observations, with units of Nm, and the formula for calculating ψ is:

[0066]

[0067] 1.3) Design an adaptive equation to estimate the uncertain parameter w, and obtain an estimate of the uncertain parameter w.

[0068] The adaptive equation for the uncertain parameter w is:

[0069]

[0070] Where t represents the running time of the control algorithm, in seconds; τ represents the integral variable, in seconds; dτ represents the derivative operation with respect to τ; Γ represents a design constant; σ² represents another design constant; and s represents the error variable, calculated using the following formula:

[0071]

[0072] Where λ represents a design positive constant greater than 0, e = x1 - x 1d The control error representing the master cylinder pressure, where x 1d This represents the target master cylinder pressure, in MPa. This represents the derivative of the master cylinder pressure control error with respect to time. s, e, and All represent intermediate values ​​after calculation, and no unit needs to be specified.

[0073] P o Both B2 and B2 are constant matrices, and their calculation formulas are as follows:

[0074]

[0075] ε0 is a variable related to the error, represented as follows:

[0076]

[0077] Where ε1 and ε2 represent the transformation errors, calculated by the following formula:

[0078]

[0079] in, This represents the derivative of ε1 with respect to time.

[0080] 1.4) Estimates based on uncertain parameters And a pre-designed master cylinder pressure controller, which receives the current input to the servo motor.

[0081] The current input of the servo motor is:

[0082]

[0083] in, This represents the derivative of the target master cylinder pressure with respect to time, in MPa / s. The second derivative of the target master cylinder pressure with respect to time, in MPa / s. 2 ;x1d , and All of these are target values ​​and related variables, which are known quantities.

[0084] 2) Design the logic threshold control method for increasing and decreasing pressure in the wheel cylinder, and determine the upper limit of the allowable pressure error of the wheel cylinder.

[0085] like Figure 3 As shown, after the wheel cylinder pressure regulation is started, it first goes through an initialization phase (i.e., powering on the controller), and then enters the pressure holding 1 state; in the pressure holding 1 state, when the wheel cylinder measures pressure p... w Greater than the target wheel cylinder pressure p wd When the pressure is reduced, it enters a decompression state. In the decompression state, when the wheel cylinder measures the pressure p... w Less than the target cylinder pressure p wd When it enters the pressure holding state 2; in the pressure holding state 1, when the wheel cylinder measures the pressure p w Less than the target cylinder pressure p wd When it enters the pressurization state, in the pressurization state, when the wheel cylinder measures the pressure p w Greater than the target wheel cylinder pressure p wd When it enters the pressure holding state 2; in the pressure holding state 2, when the wheel cylinder measures pressure p w Less than the target cylinder pressure p wd The upper limit of the allowable pressure error Δp ​​between the wheel cylinder and the cylinder w The difference, or the wheel cylinder measured pressure p w Greater than the target wheel cylinder pressure p wd The upper limit of the allowable pressure error Δp ​​between the wheel cylinder and the cylinder w When the sum is equal, it enters the holding pressure 1 state.

[0086] 3) Based on determining the upper limit of the allowable pressure error of the wheel cylinder, the control parameters of the wheel cylinder pressure regulating switch solenoid valve are calculated using the adaptive neural network switching solenoid valve control method.

[0087] like Figure 4 As shown, the adaptive neural network switching solenoid valve model established in this embodiment includes a guide controller, an inverse model controller, an inner loop controller, a system identification network, and an output controller. The input to the guide controller is the target wheel cylinder pressure p. wd and cylinder pressure measurement p w The output is the first control parameter u. GC The input to the inverse model controller is the target wheel cylinder pressure p. wd and actual control output u v The output is the second control parameter u. IMNC The input to the inner loop controller is the target wheel cylinder pressure p. wd and the output of the system identification network The output is the third control parameter u.SINC The input to the system identification network is the wheel cylinder measured pressure p. w and the actual control output u of the system v The output is the identified pressure. The output controller is based on the first control parameter u GC Second control parameter u IMNC and the third control parameter u SINC The final control parameters of the can-opening solenoid valve are obtained.

[0088] Specifically, the adaptive neural network switching solenoid valve control method proposed in this embodiment includes the following steps:

[0089] 3.1) Based on the target wheel cylinder pressure p wd and cylinder pressure measurement p w Using a pre-designed guide controller, the first control parameter u is calculated. GC .

[0090] In this embodiment, the guiding controller is set as a proportional-integral-derivative type controller, and its output is expressed as:

[0091]

[0092] Where, k p ,k i and k d Represents non-negative design parameters; e r This represents the wheel cylinder pressure error, and e r =p w -p wd .

[0093] 3.2) Based on the target wheel cylinder pressure p wd and actual control output u v The second control parameter u is obtained by using a pre-designed inverse model controller. IMNC .

[0094] In this embodiment, the inverse model controller utilizes a neural network to fit the inverse dynamics of the system. The input of this neural network is the wheel cylinder measured pressure p. w and the system's actual control output u v The output is the second control parameter. The neural network here includes, but is not limited to, multilayer perceptron networks, radial basis function neural networks, etc.

[0095] 3.3) Measure the pressure p according to the wheel cylinder w The actual control output u of the system v and target wheel cylinder pressure p wd The third control parameter u is obtained by using a pre-designed system identification neural network and inner loop controller.SINC .

[0096] Specifically, it includes the following steps:

[0097] 3.3.1) Measure the pressure p according to the wheel cylinder. w and the actual control output u of the system v By utilizing a pre-designed system recognition neural network, the recognition pressure can be obtained.

[0098] Specifically, the system identification neural network in this embodiment includes, but is not limited to, multilayer perceptron networks and radial basis function neural networks. The input to the system identification neural network is the wheel cylinder measured pressure p. w and the system's actual control output u v The output is the identified pressure.

[0099] 3.3.2) Based on identification pressure and target wheel cylinder pressure p wd The third control parameter u is obtained by using a pre-designed inner loop controller. SINC .

[0100] In this embodiment, the inner loop controller is configured as a proportional-integral-derivative controller, and its input is the identification pressure. The target wheel cylinder pressure is output as the third control parameter u. SINC :

[0101]

[0102] in, This represents the identification pressure output by the system identification network, measured in MPa.

[0103] 3.4) Based on the first control parameter u GC Second control parameter u IMNC and the third control parameter u SINC The final control parameters of the switching solenoid valve are obtained.

[0104] In this embodiment, pulse width modulation (PWM) is used to control the solenoid valve, and the final control parameter u of the solenoid valve is... v The calculation formula is:

[0105] u v =u GC +u SINC +u IMNC (12)

[0106] Among them, u GC To guide the controller output, unitless; u SINCUnitless; u IMNC This is the output of the inverse model controller and has no unit.

[0107] 4) Based on the obtained master cylinder pressure control parameters and solenoid valve control parameters, the master cylinder pressure and solenoid valve of the brake-by-wire system are controlled to achieve wheel cylinder pressure regulation of the brake-by-wire system.

[0108] Example 2

[0109] The above-described embodiment 1 provides a method for regulating wheel cylinder pressure in a brake-by-wire system. Correspondingly, this embodiment provides a system for regulating wheel cylinder pressure in a brake-by-wire system. The system provided in this embodiment can implement the wheel cylinder pressure regulation method of embodiment 1. This system can be implemented through software, hardware, or a combination of both. For example, the system may include integrated or separate functional modules or units to execute the corresponding steps in the methods of embodiment 1. Since the system in this embodiment is basically similar to the method embodiment, the description process in this embodiment is relatively simple. Relevant details can be found in the description of embodiment 1. The system embodiment provided in this embodiment is merely illustrative.

[0110] This embodiment provides a wheel cylinder pressure regulation system for a brake-by-wire system, comprising:

[0111] The master cylinder pressure control parameter acquisition module is used to estimate the disturbance and uncertainty parameters of the brake-by-wire system based on the pre-established dynamic model of the master cylinder pressure change of the motor servo hydraulic brake-by-wire system, and obtain the master cylinder pressure control parameters based on the estimation results.

[0112] The wheel cylinder pressure increase / decrease logic threshold control module is used to design the wheel cylinder pressure increase / decrease logic threshold control method and determine the upper limit of the wheel cylinder's allowable pressure error.

[0113] The solenoid valve control parameter acquisition module is used to calculate the control parameters of the wheel cylinder pressure regulating solenoid valve based on the adaptive neural network solenoid valve control method, based on the determination of the upper limit of the allowable pressure error of the wheel cylinder.

[0114] The wheel cylinder pressure regulation module is used to control the master cylinder pressure and the solenoid valve of the brake-by-wire system based on the obtained master cylinder pressure control parameters and the solenoid valve control parameters, thereby realizing the wheel cylinder pressure regulation of the brake-by-wire system.

[0115] Example 3

[0116] This embodiment provides a processing device corresponding to the wheel cylinder pressure adjustment method of the brake-by-wire system provided in Embodiment 1. The processing device can be a processing device for a client, such as a mobile phone, laptop, tablet computer, desktop computer, etc., to execute the method of Embodiment 1.

[0117] The processing device includes a processor, a memory, a communication interface, and a bus. The processor, memory, and communication interface are connected via the bus to enable communication between them. The memory stores a computer program that can run on the processor. When the processor runs the computer program, it executes the wheel cylinder pressure regulation method of the brake-by-wire system provided in Embodiment 1.

[0118] In some embodiments, the memory may be high-speed random access memory (RAM), and may also include non-volatile memory, such as at least one disk storage device.

[0119] In other embodiments, the processor can be a general-purpose processor of various types, such as a central processing unit (CPU) or a digital signal processor (DSP), and is not limited thereto.

[0120] Example 4

[0121] The wheel cylinder pressure adjustment method of the brake-by-wire system in Embodiment 1 can be specifically implemented as a computer program product. The computer program product may include a computer-readable storage medium on which computer-readable program instructions for executing the wheel cylinder pressure adjustment method of the brake-by-wire system described in Embodiment 1 are loaded.

[0122] A computer-readable storage medium can be a tangible device that holds and stores instructions for use by an instruction execution device. A computer-readable storage medium can be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any combination thereof.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for regulating wheel cylinder pressure in a brake-by-wire system, characterized in that, Includes the following steps: Based on the pre-established dynamic model of the master cylinder pressure change of the motor servo hydraulic brake-by-wire system, the disturbance and uncertainty parameters of the brake-by-wire system are estimated, and the master cylinder pressure control parameters are obtained based on the estimation results. A threshold control method for increasing and decreasing pressure in wheel cylinders is designed, and the upper limit of the allowable pressure error of wheel cylinders is determined. Based on determining the upper limit of the allowable pressure error of the wheel cylinder, the control parameters of the wheel cylinder pressure regulating solenoid valve are calculated using an adaptive neural network switching solenoid valve control method. Based on the obtained master cylinder pressure control parameters and solenoid valve control parameters, the master cylinder pressure and solenoid valve of the brake-by-wire system are controlled to achieve wheel cylinder pressure regulation of the brake-by-wire system. The dynamic model of the master cylinder pressure change based on the pre-established motor-servo hydraulic brake-by-wire system estimates the disturbance and uncertainty parameters of the brake-by-wire system. Based on the estimation results, the master cylinder pressure control parameters are obtained, including: A dynamic model of the pressure change in the master cylinder of a motor-servo hydraulic linear control system is established. Based on the dynamic model of the pressure change in the master cylinder, a disturbance observer is designed to obtain the observed values ​​of the lumped disturbance of the master cylinder system. Design an adaptive equation to estimate uncertain parameters, and obtain the uncertain parameters. The estimated value; Based on the observed values ​​of the lumped disturbance of the master cylinder system, the estimated values ​​of the uncertain parameters, and the pre-designed master cylinder pressure controller, the master cylinder pressure control parameters are obtained.

2. The wheel cylinder pressure adjustment method for a brake-by-wire system as described in claim 1, characterized in that, The dynamic model of the pressure change in the master cylinder is expressed as follows: in, Represents the hydraulic pressure inside the master cylinder, in units of ; The rate of change of pressure in the master cylinder, i.e., the hydraulic pressure within the master cylinder. The derivative with respect to time, in units of ; Represents the rotational speed of the servo motor, in units of ; Represents the equivalent frictional torque, with units of . This was obtained from measurements of the master cylinder system; Represents an uncertain parameter, in units of ; This represents the current input of the servo motor, in units of... ; This represents the torque gain of the servo motor, measured in units of... ; Represents the cross-sectional area of ​​the master cylinder piston, in units of... ; The reduction ratio represents the distance from the rotation angle of the servo motor to the displacement of the master cylinder piston, in units of... ; Represents the lumped sum of other uncertain disturbances in the master cylinder system, in units of ; and Represent and The first derivative with respect to time.

3. The method for adjusting wheel cylinder pressure in a brake-by-wire system as described in claim 1, characterized in that, Based on determining the upper limit of the allowable pressure error of the wheel cylinder, and using an adaptive neural network-based solenoid valve control method, the control parameters of the wheel cylinder pressure regulating solenoid valve are calculated, including: Based on the target wheel cylinder pressure and cylinder pressure measurement The first control parameters are calculated using a pre-designed guide controller. ; Based on the target wheel cylinder pressure and actual control output The second control parameters are obtained by using a pre-designed inverse model controller. ; Pressure measured from the wheel cylinder The actual control output of the system and target wheel cylinder pressure The third control parameter is obtained by using a pre-designed system identification neural network and inner loop controller. ; Based on the first control parameter Second control parameter and third control parameter The final control parameters of the switching solenoid valve are obtained.

4. The wheel cylinder pressure adjustment method for a brake-by-wire system as described in claim 3, characterized in that, The pressure is measured based on the wheel cylinder. The actual control output of the system and target wheel cylinder pressure The third control parameter is obtained by using a pre-designed system identification neural network and inner loop controller. ,include: Pressure measured from the wheel cylinder and the actual control output of the system By utilizing a pre-designed system recognition neural network, the recognition pressure can be obtained. ; Based on identification pressure and target cylinder pressure The third control parameter is obtained by using a pre-designed inner loop controller. .

5. The wheel cylinder pressure adjustment method for a brake-by-wire system as described in claim 3, characterized in that, The formula for calculating the final control parameter is as follows: in, The first control parameter to guide the output of the controller; To identify the second control parameter output by the controller; This is the third control parameter output by the inverse model controller.

6. A wheel cylinder pressure regulation system for a brake-by-wire system, characterized in that, include: The master cylinder pressure control parameter acquisition module is used to estimate the disturbance and uncertainty parameters of the brake-by-wire system based on the pre-established dynamic model of the master cylinder pressure change of the motor servo hydraulic brake-by-wire system, and obtain the master cylinder pressure control parameters based on the estimation results. The wheel cylinder pressure increase / decrease logic threshold control module is used to design the wheel cylinder pressure increase / decrease logic threshold control method and determine the upper limit of the wheel cylinder's allowable pressure error. The solenoid valve control parameter acquisition module is used to calculate the control parameters of the wheel cylinder pressure regulating solenoid valve based on the adaptive neural network solenoid valve control method, based on the determination of the upper limit of the allowable pressure error of the wheel cylinder. The wheel cylinder pressure regulation module is used to control the master cylinder pressure and the solenoid valve of the brake-by-wire system based on the obtained master cylinder pressure control parameters and the solenoid valve control parameters, so as to realize the wheel cylinder pressure regulation of the brake-by-wire system. The dynamic model of the master cylinder pressure change based on the pre-established motor-servo hydraulic brake-by-wire system estimates the disturbance and uncertainty parameters of the brake-by-wire system. Based on the estimation results, the master cylinder pressure control parameters are obtained, including: A dynamic model of the pressure change in the master cylinder of a motor-servo hydraulic linear control system is established. Based on the dynamic model of the pressure change in the master cylinder, a disturbance observer is designed to obtain the observed values ​​of the lumped disturbance of the master cylinder system. Design an adaptive equation to estimate uncertain parameters, and obtain the uncertain parameters. The estimated value; Based on the observed values ​​of the lumped disturbance of the master cylinder system, the estimated values ​​of the uncertain parameters, and the pre-designed master cylinder pressure controller, the master cylinder pressure control parameters are obtained.

7. The wheel cylinder pressure regulating system of a brake-by-wire system as described in claim 6, characterized in that, The solenoid valve control parameter acquisition module is equipped with an adaptive neural network solenoid valve model, which includes a guide controller, an inverse model controller, an inner loop controller, a system identification network, and an output controller; the input of the guide controller is the target wheel cylinder pressure. and cylinder pressure measurement The output is the first control parameter. The input to the inverse model controller is the target wheel cylinder pressure. and actual control output The output is the second control parameter. The input to the inner loop controller is the target wheel cylinder pressure. and the output of the system identification network The output is the third control parameter. The input to the system identification network is the wheel cylinder measured pressure. and the actual control output of the system The output is the identified pressure. The output controller is based on the first control parameter. Second control parameter and third control parameter The final control parameters of the can-opening solenoid valve are obtained.

8. A computer-readable storage medium for storing one or more programs, characterized in that, The one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any of the methods described in claims 1 to 5.

9. A computing device, characterized in that, include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including instructions for performing any of the methods described in claims 1 to 5.

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