An electromechanical brake system clamping force estimation method fusing multiple physical fields

Abstract

The application discloses a kind of electronic mechanical brake system clamping force estimation methods of fusion multi-physics field, belong to vehicle technical field.The method includes: through the automatic calibration motor zero position and caliper idle stroke of collision disc detection;According to motor speed, determine motor operating area, the motor operating area includes weak magnetic zone and non-weak magnetic zone;According to the motor operating area, determine motor torque;According to motor torque, motor zero position, caliper idle stroke and brake disc temperature, calculate first clamping force;According to the brake disc temperature and the first clamping force, output final clamping force.The application determines motor operating area, carries out correction in weak magnetic zone, avoids low estimate of motor torque under high-speed working condition, improves the accuracy of motor torque.Brake disc temperature is corrected to idle stroke, eliminates displacement drift caused by caliper thermal expansion, so that the clamping force estimation under the same motor position remains consistent under different temperature conditions, improves the accuracy of clamping force estimation.

Description

Technical Field

[0001] This invention belongs to the field of vehicle technology, specifically relating to a method for estimating the clamping force of an electromechanical braking system that integrates multiple physics fields. Background Technology

[0002] Electro-Mechanical Brake (EMB) systems eliminate the traditional hydraulic circuit, directly generating braking force by driving the caliper via an electric motor. Its core challenge lies in the fact that clamping force cannot be directly measured and must be estimated using models.

[0003] The existing technology has the following defects: (1) It is based on static models: it only uses a simple mapping of "motor current-torque-clamping force" and ignores factors such as temperature, wear, and changes in free stroke; (2) It does not integrate the detection of the brake disc: the zero-point calibration depends on offline operation. During vehicle operation, the thermal expansion of the caliper causes the free stroke to drift, and the estimation fails; (3) It ignores thermodynamic coupling: the increase in brake disc temperature will cause the caliper to expand thermally and the friction coefficient to decrease, which in turn leads to an increase in free stroke and a decrease in actual braking force; (4) It does not have an online calibration mechanism: after the caliper stiffness changes due to aging or corrosion, the model cannot be updated adaptively.

[0004] Therefore, there is an urgent need for a clamping force estimation method that can dynamically compensate for the effects of temperature, automatically calibrate the zero point, and integrate vehicle status feedback. Summary of the Invention

[0005] One objective of this invention is to provide a method for estimating the clamping force of an electromechanical braking system that integrates multiple physics fields, which can solve the aforementioned technical problems in the prior art.

[0006] According to a first aspect of the present invention, a method for estimating the clamping force of an electromechanical braking system that integrates multiphysics is provided, comprising:

[0007] The zero-point position of the motor and the free travel of the caliper are automatically calibrated by the touch plate detection.

[0008] The motor operating range is determined based on the motor speed, and the motor operating range includes the field weakening region and the non-field weakening region.

[0009] Determine the motor torque based on the motor's operating range;

[0010] The first clamping force is calculated based on the motor torque, the motor zero position, the caliper free travel, and the brake disc temperature.

[0011] The final clamping force is output based on the brake disc temperature and the first clamping force.

[0012] Optionally, determining the motor operating range based on the motor speed includes:

[0013] When the motor speed is less than the preset reference speed, the motor operating area is determined to be a non-weak magnetic region;

[0014] When the motor speed is greater than or equal to the preset reference speed, the motor operating region is determined to be the weak magnetic region.

[0015] Optionally, determining the motor torque based on the motor's operating range includes:

[0016] When the motor's operating region is not a field weakening region, the motor torque is calculated according to the following formula:

[0017] ;

[0018] in, This refers to the motor torque. The torque constant is This refers to the motor current.

[0019] When the motor's operating region is a weak magnetic field region, the motor torque is calculated according to the following formula:

[0020] ;

[0021] in, For the preset reference speed, This represents the real-time speed of the motor.

[0022] Optionally, calculating the first clamping force based on the motor torque, the motor zero-point position, the caliper free travel, and the brake disc temperature includes:

[0023] Calculate the caliper input torque based on the motor torque;

[0024] The effective displacement is calculated based on the current position of the motor, the zero point position of the motor, the caliper's free travel, and the temperature of the brake disc.

[0025] The first clamping force is calculated based on the effective displacement and caliper stiffness.

[0026] Optionally, the step of calculating the effective displacement based on the current position of the motor, the zero-point position of the motor, the caliper's free travel, and the brake disc temperature includes:

[0027] Calculate the effective displacement using the following formula:

[0028] ;

[0029] in, For effective displacement, This is the current position of the motor. This is the zero position of the motor. For the caliper's idle stroke, For brake disc temperature, is the coefficient of thermal expansion.

[0030] Optionally, calculating the first clamping force based on the effective displacement and caliper stiffness includes:

[0031] Calculate the first clamping force using the following formula:

[0032] ;

[0033] in, For the first clamping force, For effective displacement, For caliper stiffness, This is the static friction threshold.

[0034] Optionally, the step of outputting the final clamping force based on the brake disc temperature and the first clamping force includes:

[0035] The temperature change value is calculated based on the brake disc temperature and the first clamping force.

[0036] The brake disc temperature is updated based on the temperature change value to obtain the updated brake disc temperature.

[0037] If the updated brake disc temperature exceeds the temperature threshold, the final clamping force output is 0.

[0038] If the updated brake disc temperature does not exceed the temperature threshold, the first clamping force is output as the final clamping force.

[0039] Optionally, calculating the temperature change value based on the brake disc temperature and the first clamping force includes:

[0040] Calculate the temperature change using the following formula:

[0041] ;

[0042] ;

[0043] ;

[0044] in, This represents the temperature change value. For frictional heat generation power, To dissipate heat and reduce power loss, For time step, For brake disc quality, The specific heat capacity of the brake disc material. For the first clamping force, For vehicle speed, The coefficient of friction, The convective heat transfer coefficient is... This is the effective heat dissipation area of ​​the brake disc. For brake disc temperature, For ambient temperature, The thermal radiation efficiency of the brake disc surface. is the Stefan-Boltzmann constant.

[0045] Optionally, the method further includes:

[0046] Determine whether the vehicle deceleration is within the effective braking range;

[0047] If the vehicle deceleration is within the effective braking range, the theoretical clamping force is calculated based on the vehicle deceleration.

[0048] The caliper stiffness is updated based on the theoretical clamping force and the effective displacement.

[0049] Optionally, updating the caliper stiffness based on the theoretical clamping force and the effective displacement includes:

[0050] Update the caliper stiffness according to the following formula:

[0051] ;

[0052] in, For the updated caliper stiffness, The caliper stiffness before the update, For stiffness update coefficients, For theoretical clamping force, This is the effective displacement.

[0053] The beneficial effects of this invention are as follows: By determining the motor's operating area and making corrections in the weak magnetic field region, this invention avoids underestimation of torque under high-speed motor operation, thus improving the accuracy of motor torque. It corrects the idle travel by adjusting the brake disc temperature, eliminating displacement drift caused by caliper thermal expansion, ensuring consistent clamping force estimation at the same motor position under different temperature conditions, and improving the accuracy of clamping force estimation. It automatically calibrates the motor zero-point position and caliper idle travel after power-on or brake pad replacement, requiring no manual intervention and eliminating zero-point drift caused by factors such as brake pad wear. Furthermore, it utilizes vehicle deceleration to deduce theoretical clamping force, updating caliper stiffness using a weighted average method, and adaptively adjusting caliper stiffness to improve the accuracy of clamping force estimation. Attached Figure Description

[0054] Figure 1 This is a flowchart of a method for estimating the clamping force of an electromechanical braking system that integrates multiple physics fields, according to an embodiment of the present invention. Detailed Implementation

[0055] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0056] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0057] Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0058] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0059] In the specification of this invention, the terms "first" and "second" may explicitly or implicitly include one or more of the same feature. In the description of this invention, unless otherwise stated, "multiple" means two or more. Furthermore, in the specification, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0060] like Figure 1 As shown in the figure, this embodiment introduces a method for estimating the clamping force of an electromechanical braking system that integrates multiple physics fields, including steps 1100-1500.

[0061] Step 1100: Automatically calibrate the motor zero point position and caliper free travel by detecting the contact plate.

[0062] When the vehicle is powered on, the motor is in its initial position, typically with the calipers fully released. Due to factors such as brake pad wear and temperature changes, there is an unknown gap between the calipers and brake discs at this time. The motor moves towards the calipers at a very low speed, and the motor position and current are monitored in real time.

[0063] During the idle travel range, the motor only overcomes the friction of the transmission mechanism, and the current remains basically constant. When the caliper contacts the brake disc, the load increases sharply, and the motor current will show a significant jump.

[0064] If the displacement is less than -0.5mm, it is determined that there is no contact, and the motor continues to move forward at low speed. If the displacement is greater than or equal to -0.5mm and the current suddenly increases, it is determined that there is contact, the motor zero point position is recorded, and the caliper free travel is calibrated to 0.5mm.

[0065] By employing low-speed propulsion and current monitoring, the critical position where the caliper just contacts the brake disc is precisely located. A fixed free travel value is set as the benchmark for subsequent calculations, avoiding zero-point drift caused by factors such as brake pad wear and temperature changes, thus ensuring the accuracy of clamping force estimation.

[0066] Step 1200: Determine the motor operating area based on the motor speed. The motor operating area includes the field weakening zone and the field non-field weakening zone.

[0067] Specifically, when the motor speed is less than the preset reference speed, the motor working area is determined to be a non-weakening magnetic region; when the motor speed is greater than or equal to the preset reference speed, the motor working area is determined to be a weakening magnetic region.

[0068] The base speed is set to 3000 rpm. When the motor speed is less than 3000 rpm, it is considered to be in the non-weakening field zone. When the motor speed is greater than or equal to 3000 rpm, it is considered to be in the weakening field zone.

[0069] Step 1300: Determine the motor torque based on the motor operating range.

[0070] When the motor's operating region is not in the field weakening zone, the motor torque is calculated using the following formula:

[0071] ;

[0072] in, This refers to the motor torque. The torque constant is This refers to the motor current.

[0073] When the motor's operating region is in the weak magnetic field zone, the motor torque is calculated using the following formula:

[0074] ;

[0075] in, For the preset reference speed, This represents the real-time speed of the motor.

[0076] In the non-field weakening region, the motor torque is directly proportional to the motor current, and the torque constant is constant, allowing the motor to output maximum torque. In the field weakening region, because the back electromotive force increases with speed, the magnetic field needs to be weakened to maintain voltage balance, resulting in a decrease in torque for the same current. A correction factor is then applied. This attenuation relationship is described: the higher the real-time speed of the motor, the lower the motor torque.

[0077] Step 1400: Calculate the first clamping force based on the motor torque, the motor zero position, the caliper free stroke, and the brake disc temperature.

[0078] Specifically, step 1400 includes steps 1410-1430.

[0079] Step 1410: Calculate the caliper input torque based on the motor torque.

[0080] Calculate the caliper input torque using the following formula:

[0081] ;

[0082] in, Input torque to the caliper, This refers to the motor torque. For the reduction ratio, For transmission efficiency.

[0083] Step 1420: Calculate the effective displacement based on the current position of the motor, the zero point position of the motor, the caliper free travel, and the temperature of the brake disc.

[0084] The current position of the motor can be obtained through sensor detection. The motor zero-point position is the motor position caliper just making contact with the brake disc, as calipered during the disc contact detection phase. The caliper free travel represents the gap from the contact point to when the caliper actually begins to produce elastic deformation.

[0085] The distance the motor moves from the contact point can be calculated using the motor's current position and its zero-point position. During braking, the brake disc's temperature rise causes additional expansion. This additional expansion rate is used to correct for the aforementioned distance, resulting in the effective displacement that truly causes the caliper to elastically deform.

[0086] Specifically, the effective displacement is calculated according to the following formula:

[0087] ;

[0088] in, For effective displacement, This is the current position of the motor. This is the zero position of the motor. For the caliper's idle stroke, For brake disc temperature, is the coefficient of thermal expansion.

[0089] 25°C is the reference temperature, serving as the baseline for thermal expansion correction. When the brake disc temperature rises, the caliper also expands due to heat, causing the original caliper travel to increase. Because caliper expansion increases the gap between the friction pads and the disc, the motor needs to travel a longer distance to eliminate the gap.

[0090] When the brake disc temperature rises, the caliper free travel increases, and the effective displacement under the same motor position... To reduce the clamping force, the motor needs a larger displacement to achieve the same clamping force. In the above formula, the idle stroke changes linearly with temperature. For common metallic materials, this linear approximation is sufficiently accurate in the range of 25-300℃.

[0091] Step 1430: Calculate the first clamping force based on the effective displacement and caliper stiffness.

[0092] Calculate the first clamping force using the following formula:

[0093] ;

[0094] in, For the first clamping force, For effective displacement, For caliper stiffness, This is the static friction threshold.

[0095] The static friction threshold includes the static friction between the caliper piston and the seal ring, such as the elastic deformation and frictional resistance of the seal ring that needs to be overcome when the piston first begins to move. It also includes the static friction of the guide pin or transmission mechanism, such as the initial friction of transmission mechanisms like ball screws and gears.

[0096] When effective displacement When the elastic force is very small, the theoretical elastic force This may not be enough to overcome these static resistances, and in fact, no clamping force will be generated. Therefore, only when the following conditions are met... Only output the calculated value when the condition is met. Otherwise, force an output of 0 to avoid false clamping force output due to displacement noise or minor vibrations.

[0097] Step 1500: Output the final clamping force based on the brake disc temperature and the first clamping force.

[0098] Specifically, step 1500 includes:

[0099] Step 1510: Calculate the temperature change value based on the brake disc temperature and the first clamping force.

[0100] Specifically, the temperature change is calculated using the following formula:

[0101] ;

[0102] ;

[0103] ;

[0104] in, This represents the temperature change value. For frictional heat generation power, To dissipate heat and reduce power loss, For time step, For brake disc quality, The specific heat capacity of the brake disc material. For the first clamping force, For vehicle speed, The coefficient of friction, The convective heat transfer coefficient is... This is the effective heat dissipation area of ​​the brake disc. For brake disc temperature, For ambient temperature, The thermal radiation efficiency of the brake disc surface. is the Stefan-Boltzmann constant.

[0105] The temperature change is the temperature increment per unit time step. During braking, the work done by friction is converted into heat, which is input into the system and expressed as frictional heat generation power. In addition, the system loses heat to the environment through convection and radiation, which is expressed as power loss due to heat dissipation. Net power is the power generated by frictional heat. With heat dissipation power loss The difference over the time step The net heat inside is This heat causes a change in the temperature of the brake disc.

[0106] In scenarios such as the initial stage of emergency braking or continuous downhill braking, frictional heat generation exceeds heat dissipation, leading to a buildup of net heat and an increase in brake disc temperature. In scenarios such as a long downhill at constant speed with sufficient heat dissipation, the brake disc temperature remains stable. During the cooling phase after braking, heat dissipation is even greater, causing the brake disc to release heat and its temperature to decrease.

[0107] Step 1520: Update the brake disc temperature based on the temperature change value to obtain the updated brake disc temperature.

[0108] The updated brake disc temperature is the sum of the original brake disc temperature and the temperature change value. If the temperature change value is positive, the brake disc temperature rises, and the updated brake disc temperature is higher than the original brake disc temperature. If the temperature change value is negative, the brake disc temperature falls, and the updated brake disc temperature is lower than the original brake disc temperature.

[0109] Step 1530: If the updated brake disc temperature exceeds the temperature threshold, the final clamping force is output as 0.

[0110] The temperature threshold is 300℃. When the brake disc temperature exceeds 300℃, the clamping force output is forcibly disabled to ensure safety.

[0111] Step 1540: If the updated brake disc temperature does not exceed the temperature threshold, the first clamping force is output as the final clamping force.

[0112] If the brake disc temperature does not exceed the temperature threshold, the first clamping force can be output directly.

[0113] In this embodiment, the method further includes steps 2100-2300.

[0114] Step 2100: Determine whether the vehicle deceleration is within the effective braking range.

[0115] The effective braking range is 0.1-10 m / s. 2 The lower limit of deceleration is used to avoid excessive back-calculation errors caused by interference from sensor noise, wind resistance, road gradient, etc., when the vehicle speed is extremely low or close to stopping. The upper limit of deceleration is used to exclude emergency braking or conditions close to the traction limit, in which case ABS may be activated or tire slippage may occur, and the vehicle dynamics model is no longer applicable.

[0116] Step 2200: If the vehicle deceleration is within the effective braking range, calculate the theoretical clamping force based on the vehicle deceleration.

[0117] In an EMB system, the clamping force itself is unknown, but vehicle deceleration can be measured by sensors. Under stable braking conditions, there is a definite mechanical relationship between deceleration and clamping force. As the system ages, caliper stiffness may decrease (e.g., due to corrosion or increased brake pad compression). If the same caliper stiffness is used in this case, the estimated clamping force will be too high.

[0118] Specifically, the theoretical clamping force is calculated according to the following formula:

[0119] ;

[0120] in, For theoretical clamping force, For the overall vehicle quality, To slow down the vehicle, The coefficient of friction of the brake disc. This refers to the effective friction area of ​​the brake disc.

[0121] Step 2300: Update the caliper stiffness based on the theoretical clamping force and the effective displacement.

[0122] Update the caliper stiffness according to the following formula:

[0123] ;

[0124] in, For the updated caliper stiffness, The caliper stiffness before the update, For stiffness update coefficients, For theoretical clamping force, This is the effective displacement.

[0125] The updated caliper stiffness is used for clamping force calculation in the next control cycle. Stiffness update factor. Setting it to 0.8 indicates slow updates, which can track slow stiffness changes (such as wear and corrosion) while avoiding drastic jumps caused by noise from a single measurement or deceleration fluctuations. Because the stiffness update factor is 0.8, the new caliper stiffness responds slowly to a single observation, so frequent slight braking can gradually update the caliper stiffness without abrupt changes due to a single error.

[0126] This invention improves the accuracy of motor torque estimation by determining the motor's operating area and making corrections in the weak magnetic field region, thus avoiding torque underestimation under high-speed conditions. It also corrects for the idle travel by adjusting the brake disc temperature, eliminating displacement drift caused by caliper thermal expansion and ensuring consistent clamping force estimation at the same motor position under different temperature conditions. The invention automatically calibrates the motor zero-point position and caliper idle travel after power-on or brake pad replacement, eliminating zero-point drift caused by brake pad wear and other factors. Furthermore, it utilizes vehicle deceleration to deduce theoretical clamping force and updates caliper stiffness using a weighted average method, adaptively adjusting caliper stiffness to further improve the accuracy of clamping force estimation.

[0127] While specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention.

[0128] Those skilled in the art will recognize that the modules and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0129] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described apparatus and equipment can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0130] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or modules may be electrical, mechanical, or other forms.

[0131] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of the embodiments of the present invention, depending on actual needs.

[0132] In addition, the functional modules in the embodiments of the present invention can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0133] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0134] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

[0135] It should be understood that the sequence numbers of the steps in the invention's content and embodiments do not absolutely imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention. The foregoing description of embodiments of this disclosure has been provided for illustrative and descriptive purposes. The foregoing description is not exhaustive and is not intended to limit this disclosure to the exact form disclosed. Various modifications and variations may exist based on the foregoing teachings, or various modifications and variations may be derived from the practice of this disclosure. These embodiments were chosen and described to illustrate the principles of this disclosure and its practical application, so that those skilled in the art can utilize this disclosure in various implementations and modifications suitable for the specific purpose of the concept.

Claims

1. A method for estimating the clamping force of an electromechanical braking system that integrates multiphysics, characterized in that, include: The zero-point position of the motor and the free travel of the caliper are automatically calibrated by the touch plate detection. The motor operating range is determined based on the motor speed, and the motor operating range includes the field weakening region and the non-field weakening region. Determine the motor torque based on the motor's operating range; The first clamping force is calculated based on the motor torque, the motor zero position, the caliper free travel, and the brake disc temperature. The final clamping force is output based on the brake disc temperature and the first clamping force.

2. The method for estimating clamping force in an electromechanical braking system integrating multiphysics as described in claim 1, characterized in that, The step of determining the motor operating range based on the motor speed includes: When the motor speed is less than the preset reference speed, the motor operating area is determined to be a non-weak magnetic region; When the motor speed is greater than or equal to the preset reference speed, the motor operating region is determined to be the weak magnetic region.

3. The method for estimating clamping force in an electromechanical braking system integrating multiphysics as described in claim 1, characterized in that, Determining the motor torque based on the motor's operating range includes: When the motor's operating region is not a field weakening region, the motor torque is calculated according to the following formula: ； in, This refers to the motor torque. The torque constant is This refers to the motor current. When the motor's operating region is a weak magnetic field region, the motor torque is calculated according to the following formula: ； in, For the preset reference speed, This represents the real-time speed of the motor.

4. The method for estimating clamping force of an electromechanical braking system integrating multiphysics as described in claim 1, characterized in that, The calculation of the first clamping force based on the motor torque, the motor zero-point position, the caliper free travel, and the brake disc temperature includes: Calculate the caliper input torque based on the motor torque; The effective displacement is calculated based on the current position of the motor, the zero point position of the motor, the caliper's free travel, and the temperature of the brake disc. The first clamping force is calculated based on the effective displacement and caliper stiffness.

5. The method for estimating clamping force of an electromechanical braking system integrating multiphysics as described in claim 4, characterized in that, The calculation of effective displacement based on the current position of the motor, the zero-point position of the motor, the caliper's free travel, and the brake disc temperature includes: Calculate the effective displacement using the following formula: ； in, For effective displacement, This is the current position of the motor. This is the zero position of the motor. For the caliper's idle stroke, For brake disc temperature, is the coefficient of thermal expansion.

6. The method for estimating clamping force of an electromechanical braking system integrating multiphysics as described in claim 4, characterized in that, The calculation of the first clamping force based on the effective displacement and caliper stiffness includes: Calculate the first clamping force using the following formula: ； in, For the first clamping force, For effective displacement, For caliper stiffness, This is the static friction threshold.

7. The method for estimating clamping force of an electromechanical braking system integrating multiphysics as described in claim 1, characterized in that, The step of outputting the final clamping force based on the brake disc temperature and the first clamping force includes: The temperature change value is calculated based on the brake disc temperature and the first clamping force. The brake disc temperature is updated based on the temperature change value to obtain the updated brake disc temperature. If the updated brake disc temperature exceeds the temperature threshold, the final clamping force output is 0. If the updated brake disc temperature does not exceed the temperature threshold, the first clamping force is output as the final clamping force.

8. The method for estimating clamping force of an electromechanical braking system integrating multiphysics as described in claim 7, characterized in that, The calculation of the temperature change value based on the brake disc temperature and the first clamping force includes: Calculate the temperature change using the following formula: ； ； ； in, This represents the temperature change value. For frictional heat generation power, To dissipate heat and reduce power loss, For time step, For brake disc quality, The specific heat capacity of the brake disc material. For the first clamping force, For vehicle speed, The coefficient of friction, The convective heat transfer coefficient is... This is the effective heat dissipation area of ​​the brake disc. For brake disc temperature, For ambient temperature, The thermal radiation efficiency of the brake disc surface. is the Stefan-Boltzmann constant.

9. The method for estimating clamping force of an electromechanical braking system integrating multiphysics as described in claim 4, characterized in that, The method further includes: Determine whether the vehicle deceleration is within the effective braking range; If the vehicle deceleration is within the effective braking range, the theoretical clamping force is calculated based on the vehicle deceleration. The caliper stiffness is updated based on the theoretical clamping force and the effective displacement.

10. The method for estimating clamping force of an electromechanical braking system integrating multiphysics as described in claim 9, characterized in that, The step of updating the caliper stiffness based on the theoretical clamping force and the effective displacement includes: Update the caliper stiffness according to the following formula: ； in, For the updated caliper stiffness, The caliper stiffness before the update For stiffness update coefficients, For theoretical clamping force, This is the effective displacement.

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