An EMB Clamping Force Control Method Based on a High-Order Full-Drive System

Abstract

The present invention discloses an EMB clamping force control method based on a high-order fully actuated system, comprising the following steps: S1, obtaining a target clamping force value; S2, establishing a simplified dynamic model of a third-order EMB system for corner control; S3, through clamping force separation processing, converting it from a model for corner control to a high-order fully actuated model for clamping force control; S4, designing a controller based on the high-order fully actuated control method. When designing the controller of the electromechanical braking system based on the high-order fully actuated control method, its control law can be synthesized in a simple and explicit manner to obtain a desired linear closed-loop system with arbitrarily specified pole positions, and only one parameter needs to be adjusted, greatly simplifying the tuning task. The EMB clamping force control method based on the high-order fully actuated system provided by the present invention effectively overcomes the nonlinear stiffness and frictional load disturbances existing in the electromechanical braking system.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile manufacturing, and particularly relates to an EMB clamping force control method based on a high-order all-wheel drive system. Background Art

[0002] The electro-mechanical braking system completely cancels the hydraulic system and is an electronically controlled pure mechanical braking system. It has outstanding advantages such as a compact structure, rapid response, precise control, and strong compatibility, and is considered the best solution for future automotive braking systems. Under the condition of accurately obtaining the braking command, how to accurately and quickly control the clamping force of each wheel under external interference and efficiently design the controller of the desired closed-loop system at any pole position is the current research focus and difficulty of the electro-mechanical braking system.

[0003] In the research on electro-mechanical braking control methods, traditional three-closed-loop control, sliding mode control, linear active disturbance rejection control, neural network control, etc. are mostly used. However, in the above control methods, some have complex adjustment parameters, and some use state space models. The state space model emphasizes the state vector, which is suitable for state solution and estimation, and does not provide enough convenience for the solution of control inputs. In addition, problems such as non-linear stiffness and friction load disturbance in the electro-mechanical braking system seriously hinder the realization of its high-precision control effect. Therefore, there is an urgent need for a control method with simple adjustment parameters and precise control to achieve the rapid and accurate following of the clamping force to the target value. Summary of the Invention

[0004] In view of the above problems, the present invention provides an EMB clamping force control method based on a high-order all-wheel drive system, aiming to solve the problems existing in the prior art.

[0005] The specific technical solutions are as follows:

[0006] An EMB clamping force control method based on a high-order all-wheel drive system includes the following steps:

[0007] S1. Obtain the target clamping force value F d ;

[0008] S2. Establish a simplified dynamic model of a third-order EMB system for corner control

[0009] S3. Through clamping force separation processing, convert it from a model for corner control to a high-order all-wheel drive model for clamping force control, and perform the following transformation on the EMB system model:

[0010] The classical relationship between the clamping force and the motor angle is often expressed in the form of a cubic polynomial:

[0011] F cl = k3(θ - θ g )3 + k2(θ - θ g ) 2 + k1(θ - θ g ) + k0;

[0012] According to the above relationship, the clamping force is separated as follows:

[0013]

[0014] In the formula, F lc is the linear part of the clamping force; F nc is the non - linear part of the clamping force; k lc is the linear proportional coefficient of the clamping force; θ g is the motor rotation angle corresponding to the EMB braking gap;

[0015] Combined with the state - space equation of the EMB system model for angle control above, the state - space equation of the simplified dynamic model of the EMB system for clamping force control can be obtained:

[0016]

[0017] After corresponding transformation of the EMB system model, it is transformed into a high - order full - drive model for clamping force control:

[0018]

[0019] In the formula, the lumped disturbance d contains the unmodeled dynamics within the system and external disturbance variables;

[0020] S4. Design a controller based on the high - order full - drive control method to obtain the primary composite control law. The obtaining method is as follows. Based on the high - order full - drive control method, the composite control law u of the EMB high - order full - drive model consists of a feed - forward compensation controller u f and a feedback closed - loop controller u c :

[0021] u = u c + u f

[0022] The feed - forward compensation controller is:

[0023]

[0024] The feedback closed - loop controller is:

[0025]

[0026] Among them, represents the clamping force tracking error, where F cl is the clamping force, and the first - order derivative coefficient a0 = B m / Jm T; The second derivative coefficient a1 = (J m +TB m ) / J m T; The non - zero coefficient b0 of the control input = k lc K / J m T;

[0027] S5. Design a LESO (Linear Extended State Observer) to estimate the unmodeled dynamics and external disturbance variables in the system, obtain the lumped disturbance, and use the lumped disturbance to correct the primary composite control law to obtain the corrected composite control law;

[0028] S6. Input the corrected composite control law into the actual EMB system, and the driver can be controlled to output the target clamping force value.

[0029] The above - mentioned EMB clamping force control method based on a high - order fully - actuated system also has the following characteristics. The simplified dynamic model of the EMB system for angle control includes a mechanical subsystem model and an electrical subsystem model. The mechanical subsystem model is:

[0030]

[0031] The electrical subsystem model is:

[0032]

[0033] In the formula, θ m and ω m are respectively the position and speed of the motor shaft; J m is the moment of inertia; B m is the viscous friction coefficient; T L is the load torque including the clamping force, external disturbance variables and non - linear friction force; n p is the number of motor pole pairs; Ψ f is the magnetic flux; i d and i q are respectively the d - q axis stator currents; u d and u q are respectively the corresponding stator voltages; R a is the stator resistance; L d and L q are respectively the d - q axis stator inductances, and T m is the motor output torque.

[0034] Replace the electrical subsystem model with a first - order inertial system model;

[0035]

[0036] In the formula, u is the control input of the motor servo driver; Gc (s) is the transfer function from u to T m ; K and T are the equivalent gain and time constant respectively, and the equivalent gain and time constant are obtained by using the MATLAB system identification toolbox;

[0037] The state - space equation of the simplified dynamic model of the above - mentioned EMB system for corner control is as follows:

[0038]

[0039] The above - mentioned EMB clamping force control method based on the high - order fully - actuated system also has the following characteristics. The EMB system model is transformed as follows:

[0040] The classical relationship between the clamping force and the motor angle is often expressed in the form of a cubic polynomial:

[0041] F cl = k3(θ - θ g ) 3 + k2(θ - θ g ) 2 + k1(θ - θ g )+ k0;

[0042] According to the above relationship, the clamping force is separated as follows:

[0043]

[0044] In the formula, F lc is the linear part of the clamping force; F nc is the non - linear part of the clamping force; k lc is the linear proportional coefficient of the clamping force; θ g is the motor rotation angle corresponding to the EMB braking clearance;

[0045] Combined with the state - space equation of the above - mentioned EMB system model for corner control, the state - space equation of the simplified dynamic model of the EMB system for clamping force control can be obtained:

[0046]

[0047] After the corresponding transformation of the EMB system model, it is transformed into a high - order fully - actuated model for clamping force control:

[0048]

[0049] In the formula, the lumped disturbance d includes the unmodeled dynamics within the system and the external disturbance variables.

[0050] The above EMB clamping force control method based on a high-order fully actuated system also has the following characteristics: the feedback closed-loop controller is designed as a feedback closed-loop controller with a dynamic compensator.

[0051] The feedback closed-loop controller with a first-order dynamic compensator is:

[0052]

[0053] where \(e\) represents a vector group composed of the clamping force error and its derivative, expressed as \(\omega\in R\) represents the state vector of the dynamic compensator of order 1 (which can be designed to a higher order); \(K\) e \(=[k\) e0 \(k\) e1 \(k\) e2 , \(K\) ω \(=k\) ω , \(a\) ω \(=a\) ω , \(b\) e \(=[b\) e0 \(b\) e1 \(b\) e2 all represent parameter matrices.

[0054] The above EMB clamping force control method based on a high-order fully actuated system also has the following characteristics: the process of designing the LESO extended state observer is as follows.

[0055] The dynamic state space model of the EMB system can be expressed as:

[0056]

[0057] where are the estimated values of \(b_0\), \(a_0\), and \(a_1\); the lumped disturbance \(\Delta_1\) can estimate the lumped disturbance \(d\) of the unmodeled dynamics and external disturbance variables in the system.

[0058] This state space model can be extended to the following model:

[0059]

[0060] where

[0061] Furthermore, the linear extended state observer is:

[0062]

[0063] The above EMB clamping force control method based on a high-order fully actuated system also has the following characteristics: using the extended state observer to estimate the lumped disturbance and correcting the feedforward compensation controller.

[0064] The feedforward compensation controller is modified to:

[0065]

[0066] The feedback closed-loop controller with a first-order dynamic compensator is modified to;

[0067]

[0068] Wherein,

[0069] In summary, the beneficial effects of this solution are:

[0070] In the EMB clamping force control method based on a high-order fully actuated system provided by the present invention, the controller of the electromechanical braking system is designed based on the high-order fully actuated control method. Its control law can be synthesized in a simple and explicit manner to obtain a desired linear closed-loop system with arbitrarily specified pole positions, and only one parameter needs to be determined, greatly simplifying the tuning task. The EMB clamping force control method based on a high-order fully actuated system provided by the present invention has the effect of effectively overcoming the nonlinear stiffness and frictional load disturbances existing in the electromechanical braking system. Description of the Drawings

[0071] Figure 1 It is a schematic diagram of the classical relationship between the clamping force and the motor angle;

[0072] Figure 2 It is a block diagram of a high-order fully actuated controller based on LESO and with a first-order dynamic compensator. Detailed Embodiments

[0073] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0074] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0075] The present invention will be further described below in conjunction with specific embodiments, but it is not limited to the present invention.

[0076] Figure 1 It is a schematic diagram of the classical relationship between the clamping force and the motor angle, Figure 2 It is a block diagram of a high-order fully actuated controller based on LESO and with a first-order dynamic compensator, as Figure 1 and Figure 2As shown in the figure, the EMB clamping force control method based on a high-order full-drive system provided in this embodiment includes the following steps:

[0077] S1. Obtain the target clamping force value F d ;

[0078] S2. Establish a simplified dynamic model of a third-order EMB system for corner control

[0079] S3. Through clamping force separation processing, convert it from a model for corner control to a high-order full-drive model for clamping force control;

[0080] S4. Design a controller based on the high-order full-drive control method to obtain the primary composite control law;

[0081] S5. Design a LESO extended state observer to estimate the unmodeled dynamics and external disturbance variables in the system, obtain the lumped disturbance, and use the lumped disturbance to correct the primary composite control law to obtain the corrected composite control law;

[0082] S6. Input the corrected composite control law into the actual EMB system to control the driver to output the target clamping force value.

[0083] In the above embodiment, the simplified dynamic model of the EMB system for corner control includes a mechanical subsystem model and an electrical subsystem model, where the mechanical subsystem model is:

[0084]

[0085] The electrical subsystem model is:

[0086]

[0087] In the formula, θ m and ω m are the position and speed of the motor shaft respectively; J m is the moment of inertia; B m is the viscous friction coefficient; T L is the load torque including the clamping force, external disturbance variables and non-linear friction force; n p is the number of motor pole pairs; Ψ f is the magnetic flux; i d and i q are the d-q axis stator currents respectively; u d and u q are the corresponding stator voltages respectively; R a is the stator resistance; L d and L q are the d-q axis stator inductances respectively, and T m is the motor output torque.

[0088] Replace the electrical subsystem model with a first-order inertial system model;

[0089]

[0090] where u is the control input of the motor servo driver; G c (s) is the transfer function from u to T m ; K and T are the equivalent gain and time constant respectively, and the equivalent gain and time constant are obtained using the MATLAB system identification toolbox;

[0091] The state-space equation of the simplified dynamic model of the above EMB system for corner control is:

[0092]

[0093] In the above embodiment, perform the following transformation on the EMB system model:

[0094] The classical relationship between the clamping force and the motor angle is often expressed in the form of a cubic polynomial:

[0095] F cl = k3(θ - θ g ) 3 + k2(θ - θ g ) 2 + k1(θ - θ g ) + k0(2);

[0096] Perform the following separation process on the clamping force according to the above relationship:

[0097]

[0098] where F cl is the clamping force; F lc is the linear part of the clamping force; F nc is the non-linear part of the clamping force; k lc is the linear proportional coefficient of the clamping force; θ g is the motor angle corresponding to the EMB braking gap;

[0099] Combined with the state-space equation of the above EMB system model for corner control, the state-space equation of the simplified dynamic model of the EMB system for clamping force control can be obtained:

[0100]

[0101] After performing the corresponding transformation on the EMB system model, transform it into a high-order full-drive model for clamping force control:

[0102]

[0103] In the formula, the first-order derivative coefficient a0=B m / J m T; second-order derivative coefficient a1=(J m +TB m ) / J m T; non-zero coefficient of control input b0 = k lc K / J m T; Lumped disturbance d including unmodeled dynamics within the system and external disturbance variables.

[0104] In the above embodiment, based on the high-order all-wheel drive control method, the composite control law u of the EMB high-order all-wheel drive model is composed of a feedforward compensation controller u f and feedback closed-loop controller u c constitute:

[0105] u=u c +u f (7)

[0106] The feedforward compensation controller is:

[0107]

[0108] The feedback closed-loop controller is:

[0109]

[0110] in, Indicates the clamping force tracking error.

[0111] It should be noted that in order to achieve fast, accurate and stable tracking of the clamping force, a composite control law is designed under the high-order all-wheel drive control method to obtain the ideal clamping force error tracking dynamics, and a dynamic compensator is used to provide additional degrees of freedom for improving the control performance. In order to achieve stable tracking of the clamping force, LESO is designed for online clamping force state estimation and compensation of the nonlinear part of the clamping force, the load torque including nonlinear friction, and external disturbances.

[0112] It should also be noted that the above control law is combined with the high-order all-wheel drive model to obtain

[0113]

[0114] The pole locations of the closed-loop system (10) can be determined by choosing k i (i=0,1,2) to arbitrarily assign. The characteristic polynomial of (10) is designed as

[0115] λ1(s)=(s+ω c ) 3 (11)

[0116] The control gain can be explicitly obtained as

[0117] k2 = 3ω c -a1; k1 = 3ω 2 c -a2; k0 = ω 3 c (12)

[0118] Let It can be obtained that

[0119]

[0120] where G s1 (s) represents the transfer function from s1 to e1.

[0121] It can be clearly seen from the above formula that G s1 (s) is a low-pass filter, and its filter bandwidth is defined by ω c e1 is the filtered value of s1, and it satisfies that the convergence of s1 to 0 indicates the convergence of e1 to 0.

[0122] Thus, the transfer function from s1 to e1 is obtained.

[0123] In the above embodiment, the process of designing the LESO extended state observer is as follows.

[0124] The dynamic state space model of the EMB system can be expressed as:

[0125]

[0126] where are the estimated values of b0, a0, a1; the lumped disturbance Δ1 can estimate the lumped disturbance d of the unmodeled dynamics and external disturbance variables in the system.

[0127] This state space model can be extended to the following model:

[0128]

[0129] where

[0130] Furthermore, the linear extended state observer is:

[0131]

[0132] In the above embodiment, the lumped disturbance is estimated by using the extended state observer, and the feedforward compensation controller is corrected.

[0133] The feedforward compensation controller is corrected to:

[0134]

[0135] The feedback closed-loop controller is modified to;

[0136]

[0137] wherein,

[0138] In the above embodiment, the feedback closed-loop controller is designed as a feedback closed-loop controller with a dynamic compensator:

[0139]

[0140] where e represents a vector group composed of the clamping force error and its derivative, expressed as ω ∈ R represents the state vector of the dynamic compensator of order 1 (can be designed to a higher order); K e =[k e0 k e1 k e2 , K ω =k ω , a ω =a ω , b e =[b e0 b e1 b e2 all represent parameter matrices.

[0141] Under the composite control law (7) of (8) and (9), the system (6) has the following closed-loop dynamic system:

[0142]

[0143] where

[0144] The high-order fully actuated model corresponding to the closed-loop dynamic system (15) is:

[0145]

[0146] where

[0147] β0 = a ω k e0 +b e0 k ω

[0148] β1 = k e0 +a ω (a1 + k e1 ) + b e1 k ω

[0149] β2 = a1 + ke1 +a ω (a0 + k e2 ) + b e2 k ω

[0150] β3 = a ω +a0 + k e2 (17)

[0151] Let the expected characteristic polynomial of model (16) be

[0152] λ2(s) = (s + ω c ) 4 (18)

[0153] The explicit solutions of β i (i = 0, 1, 2, 3) are as follows:

[0154]

[0155] The transfer function from d to e1 is expressed as follows:

[0156]

[0157] Then, when |d| ≤ d max and , the closed-loop characteristic polynomials given by the composite control laws (7) and (18) obtained based on (14) and (8) can ensure that the system (6) is uniformly ultimately bounded stable. Moreover, the dynamics of s1 satisfy

[0158]

[0159] Proof:

[0160] From the transfer function formula (13) from s1 to e1 and the transfer function formula (20) from d to e1, we can obtain:

[0161]

[0162] When , we can obtain

[0163]

[0164] Integrating on [0, t] gives

[0165]

[0166] Proof completed

[0167] It should also be noted that the LESO is designed as follows.

[0168] The dynamic state - space model of the EMB system can be expressed as:

[0169]

[0170] Where are the estimated values of \(b_0\), \(a_0\), and \(a_1\); the lumped disturbance \(\Delta_1\) can estimate the load torque including non - linear friction, the non - linear part of the clamping force, and external disturbances, etc.

[0171] This state - space model can be extended to the following model:

[0172]

[0173] Where

[0174] Furthermore, the linear extended state observer can be designed as:

[0175]

[0176] By the pole - placement method, the observer coefficients can be obtained as follows:

[0177]

[0178] Where \(\omega_0\) is the bandwidth parameter of the linear extended state observer.

[0179] When the derivative \(h(t)\) of the lumped disturbance is bounded, there exist a finite time \(T_1>0\) and a constant \(\sigma\) i >0 such that

[0180]

[0181] Where \(c\) is a positive integer.

[0182] When \(\omega_0\) is larger, the boundary of is smaller. Using the estimated state the first - order derivative and the second - order derivative of the clamping force and the lumped disturbance \(\Delta_1\) can greatly reduce the burden on the closed - loop controller, thus obtaining higher control accuracy.

[0183] So far, the LESO design is completed.

[0184] The high - order full - drive controller based on LESO and with a first - order dynamic compensator is modified to:

[0185] The feed - forward compensation controller is modified to

[0186]

[0187] The feedback closed - loop controller with a first - order dynamic compensator is modified to

[0188]

[0189] Among them

[0190] So far, the design of the high-order full-drive controller based on LESO and with a first-order dynamic compensator is completed, and the overall control structure of the controller is as shown in Figure 2 shown;

[0191] Stability Analysis of High-Order Full-Drive Controller Based on LESO and with a First-Order Dynamic Compensator

[0192] When the derivative h(t) of the lumped disturbance is bounded in the EMB, and the composite control law (7) is composed of Eqs. (31) and (32) and the controller gains and observer gains are obtained from Eqs. (25) and (29), the uniform ultimate boundedness of the system (6) can be guaranteed. In addition, the dynamics of s1 satisfy

[0193]

[0194] Proof: When a ω = 0, the system (6) under the composite control law (7) composed of Eqs. (31) and (32) has the following closed-loop system dynamics:

[0195]

[0196] Among them

[0197] By analogy with Eq. (15), the high-order full-drive model corresponding to Eq. (34) is:

[0198]

[0199] From Eqs. (13) and (19), the Laplace form of Eq. (35) is:

[0200]

[0201] When and at this time, it can be obtained that

[0202]

[0203] Based on (30), integrating on [T1, t] gives

[0204]

[0205] Proof completed

[0206] So far, the stability analysis of the high-order full-drive controller based on LESO and with a first-order dynamic compensator is completed.

[0207] Working principle: Use the high-order full-drive model to obtain the composite control law. Since the composite control law consists of a feedforward compensation controller and a feedback closed-loop controller, the extended state observer is used to correct the feedforward compensation controller and the feedback closed-loop controller to obtain the corrected composite control law. The corrected composite control law is input into the actual EMB system, and the drive can be controlled to output the corresponding clamping force. Under a certain magnitude of step disturbance, the target clamping force value can also be quickly restored.

[0208] The above are only the preferred embodiments of the present invention, and do not limit the implementation manners and protection scope of the present invention. For those skilled in the art, it should be realized that all the equivalent substitutions and obvious changes made by using the content of the specification of the present invention should be included in the protection scope of the present invention.

Claims

1. An EMB clamping force control method based on a high-order all-drive system, characterized in that: Including the following steps: S1. Obtain the target clamping force value F d ; S2. Establish a simplified dynamic model of the third-order EMB system for corner control S3. Through the separation process of the clamping force, transform it from the model for corner control into a high-order fully actuated model for clamping force control, and perform the following transformation on the EMB system model: The classical relationship between the clamping force and the motor angle is often expressed in the form of a cubic polynomial: F cl = k3(θ - θ g ) 3 + k2(θ - θ g ) 2 + k1(θ - θ g ) + k0; According to the above relationship, perform the following separation process on the clamping force: where, F cl is the clamping force; F lc is the linear part of the clamping force; F nc is the non-linear part of the clamping force; k lc is the linear proportionality coefficient of the clamping force; θ g is the motor rotation angle corresponding to the EMB braking gap; Combined with the state-space equation of the EMB system model for corner control, the state-space equation of the simplified dynamic model of the EMB system for clamping force control can be obtained: After performing the corresponding transformation on the EMB system model, transform it into a high-order fully actuated model for clamping force control: In the formula, the lumped disturbance d including the unmodeled dynamics in the system and the external disturbance variables; S4. Design a controller based on the high-order full-drive control method to obtain the primary composite control law. The obtaining method is as follows. Based on the high-order full-drive control method, the composite control law u of the EMB high-order full-drive model consists of a feedforward compensation controller u f and a feedback closed-loop controller u c as follows: u = u c + u f The feedforward compensation controller is: The feedback closed-loop controller is: Among them, represents the clamping force tracking error, where F cl is the clamping force, the first-order derivative coefficient a0 = B m / J m T; the second-order derivative coefficient a1 = (J m +TB m ) / J m T; the non-zero coefficient b0 of the control input = k lc K / J m T; S5. Design a LESO extended state observer to estimate the unmodeled dynamics in the system and the external disturbance variables, obtain the lumped disturbance, and use the lumped disturbance to correct the primary composite control law to obtain the corrected composite control law; S6. Input the corrected composite control law into the actual EMB system, and the driver can be controlled to output the target clamping force value.

2. The EMB clamping force control method based on a high-order all-drive system according to claim 1, characterized in that: The simplified dynamic model of the EMB system for corner control includes a mechanical subsystem model and an electrical subsystem model, where the mechanical subsystem model is: The electrical subsystem model is: where θ m and ω m are the position and speed of the motor shaft respectively; J m is the moment of inertia; B m is the viscous friction coefficient; T L is the load torque including the clamping force, external disturbance variables and non-linear friction force; n p is the number of pole pairs of the motor; Ψ f is the magnetic flux; i d and i q are the d-q axis stator currents respectively; u d and u q are the corresponding stator voltages respectively; R a is the stator resistance; L d and L q are the d-q axis stator inductances respectively, T m is the motor output torque; Replace the electrical subsystem model with a first-order inertial system model; where u is the control input of the motor servo driver; G c (s) is the transfer function from u to T m ; K and T are the equivalent gain and time constant respectively, and the equivalent gain and time constant are obtained using the MATLAB system identification toolbox; The state-space equation of the above simplified dynamic model of the EMB system for corner control is:

3. The EMB clamping force control method based on a high-order all-drive system according to claim 2, wherein: Design the feedback closed-loop controller as a feedback closed-loop controller with a dynamic compensator: The feedback closed-loop controller with a first-order dynamic compensator is; where, e represents a vector group composed of the clamping force error and its derivative, expressed as ω ∈ R represents the state vector of the dynamic compensator of order 1 (which can be designed to be of a higher order); K e =[k e0 k e1 k e2 , K ω =k ω , a ω =a ω , b e =[b e0 b e1 b e2 all represent parameter matrices.

4. An EMB clamping force control method based on a high-order all-drive system according to claim 3, characterized in that: The process of designing the LESO extended state observer is as follows, The dynamic state-space model of the EMB system can be expressed as: where are the estimated values of b0, a0, and a1; the concentrated disturbance Δ1 can estimate the lumped disturbance d of the unmodeled dynamics within the system and the external disturbance variables; This state-space model can be extended to the following model: Among them, Furthermore, the linear extended state observer is:

5. The EMB clamping force control method based on a high-order all-drive system according to claim 4, wherein: Use the extended state observer to estimate the lumped disturbance and correct the feedforward compensation controller, The feedforward compensation controller is corrected to: The feedback closed-loop controller with a first-order dynamic compensator is corrected to: Among them,

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