Electromechanical brake clamping force estimation method and device, controller, automobile and medium

Abstract

The invention relates to the technical field of automobiles, in particular to an electronic mechanical brake clamping force estimation method and device, a controller, an automobile and a medium, and aims at solving the technical problems that an existing electronic mechanical brake with a built-in sensor is large in overall size, difficult to arrange and high in single piece cost. The method comprises the following steps: acquiring a motor rotation angle of the electronic mechanical brake; according to the motor rotation angle, the transmission element lead of the electronic mechanical brake and the transmission ratio of the transmission mechanism, the piston movement stroke of the electronic mechanical brake is determined; according to the movement stroke of the piston and a pre-calibrated target corresponding table, the first caliper clamping force of the electronic mechanical brake is determined; an estimated caliper clamping force for the electromechanical brake is determined based on the first caliper clamping force for the electromechanical brake.

Description

Technical Field

[0001] This application relates to the field of automotive technology, and in particular to a method, device, controller, automobile, and medium for estimating the clamping force of an electromechanical brake. Background Technology

[0002] With the development of automotive intelligence, people have put forward higher requirements for vehicle braking precision. Electronic mechanical braking (EMB) is currently the most advanced brake-by-wire technology. It overcomes the inherent defects of traditional hydraulic braking and has advantages such as simple structure, powerful intelligent control function, high integration, faster response speed, and shorter braking distance. It is the ultimate form of braking development.

[0003] In the existing technology, the clamping force of the caliper is measured and fed back in real time by a pressure sensor built into the electromechanical brake. However, the sensor occupies the internal space of the brake, increases the overall size of the brake assembly, increases the axial dimension of the electromechanical brake, makes it inconvenient to arrange the brake on the vehicle, and leads to an increase in the overall cost of the electromechanical brake. Summary of the Invention

[0004] This application provides a method, device, controller, automobile, and medium for estimating the clamping force of an electromechanical brake, in order to solve the technical problems of large overall size, difficult layout, and high unit cost of current electromechanical brakes with built-in sensors.

[0005] Firstly, a method for estimating the clamping force of an electromechanical brake is provided, including:

[0006] The motor rotation angle of the electromechanical brake is obtained, and the motor rotation angle is the motor rotation angle when the gap between the brake disc and the brake friction pad is eliminated;

[0007] The piston stroke of the electromechanical brake is determined based on the motor rotation angle, the lead of the transmission element of the electromechanical brake, and the transmission ratio of the transmission mechanism. The transmission element is the transmission element between the transmission mechanism and the piston.

[0008] The first caliper clamping force of the electromechanical brake is determined according to the piston travel stroke and the pre-calibrated target correspondence table, wherein the target correspondence table includes the correspondence between the calibrated clamping force of the caliper and the calibrated travel stroke of the piston.

[0009] The estimated caliper clamping force of the electromechanical brake is determined based on the first caliper clamping force of the electromechanical brake.

[0010] Further, determining the first caliper clamping force of the electromechanical brake based on the piston travel stroke and a pre-calibrated target correspondence table includes:

[0011] Query the caliper clamping force corresponding to the piston travel stroke from the target mapping table;

[0012] When the caliper calibration clamping force corresponding to the piston travel stroke is found, the found caliper calibration clamping force is the first caliper clamping force;

[0013] If the caliper calibration clamping force corresponding to the piston movement stroke is not found, the caliper calibration clamping force adjacent to the piston movement stroke is retrieved from the target correspondence table, and the adjacent caliper calibration clamping force is interpolated to obtain the first caliper clamping force.

[0014] Further, determining the piston travel of the electromechanical brake based on the motor rotation angle, the lead of the transmission element of the electromechanical brake, and the transmission ratio of the transmission mechanism includes:

[0015] The piston stroke of the electromechanical brake is calculated using the following formula:

[0016]

[0017] Where, θ 电机 X represents the motor rotation angle, L represents the piston travel stroke, and i represents the transmission element lead.

[0018] Furthermore, determine whether the gap between the brake disc and the brake friction pads has been eliminated by the following method:

[0019] When the rate of change of the motor current of the electromechanical brake is greater than or equal to a preset rate of change threshold, it is determined that the gap between the brake disc and the brake friction pad is eliminated.

[0020] When the rate of change of the motor current is less than a preset rate of change threshold, it is determined that the gap between the brake disc and the brake friction pad has not been eliminated.

[0021] Further, determining the estimated caliper clamping force of the electromechanical brake based on the first caliper clamping force of the electromechanical brake includes:

[0022] The first caliper clamping force is the estimated caliper clamping force;

[0023] or;

[0024] The estimated caliper clamping force of the electromechanical brake is determined based on the first caliper clamping force and the second caliper clamping force of the electromechanical brake, wherein the second caliper clamping force is calculated based on the motor current of the electromechanical brake.

[0025] Furthermore, the clamping force of the second caliper is determined in the following manner:

[0026] The electromagnetic torque of the motor is determined based on the motor torque coefficient and motor current of the electromechanical brake.

[0027] The second caliper clamping force of the electromechanical brake is calculated based on the electromagnetic torque of the motor, the lead of the transmission element, and the efficiency of the transmission element.

[0028] Furthermore, the motor current is the motor current recorded during a locked motor or within a preset time period before the locked motor.

[0029] Further, the calculation of the second caliper clamping force of the electromechanical brake based on the electromagnetic torque of the motor, the lead of the transmission element, and the efficiency of the transmission element includes:

[0030] The second caliper clamping force of the electromechanical brake is calculated using the following formula:

[0031]

[0032] Where F2 represents the clamping force of the second caliper, KT represents the motor torque coefficient, I represents the motor current, and T 摩擦 The system friction torque of the electromechanical brake is represented by L, the lead of the transmission element is represented by η1, and the efficiency of the transmission element is represented by η1.

[0033] Further, the calculation of the second caliper clamping force of the electromechanical brake based on the electromagnetic torque of the motor, the lead of the transmission element, and the efficiency of the transmission element includes:

[0034] The second caliper clamping force of the electromechanical brake is calculated using the following formula:

[0035]

[0036] Where F2 represents the clamping force of the second caliper, KT represents the motor torque coefficient, I represents the motor current, and T 摩擦 Let L represent the system friction torque of the electromechanical brake, L represent the lead of the transmission element, η1 represent the efficiency of the transmission element, and J represent the system moment of inertia of the electromechanical brake. T represents the angular velocity of the motor. 粘滞 This represents the viscous torque of the electromechanical brake.

[0037] Further, determining the estimated caliper clamping force of the electromechanical brake based on the first caliper clamping force and the second caliper clamping force includes:

[0038] The clamping forces of the first caliper and the second caliper are weighted and averaged to obtain the estimated clamping force of the electromechanical brake.

[0039] Further, the weighted average of the first caliper clamping force and the second caliper clamping force to obtain the estimated caliper clamping force of the electromechanical brake includes:

[0040] The clamping force error coefficient is calculated, and the clamping force evaluation coefficient represents the difference between the clamping force of the first caliper and the clamping force of the second caliper.

[0041] If the clamping force error coefficient is greater than the preset coefficient threshold, a braking fault alarm will be output.

[0042] When the clamping force error coefficient is less than or equal to the preset coefficient threshold, the first caliper clamping force and the second caliper clamping force are weighted and averaged to obtain the estimated caliper clamping force of the electromechanical brake.

[0043] Secondly, an electromechanical brake clamping force estimation device is provided, comprising:

[0044] The acquisition module is used to acquire the motor rotation angle of the electromechanical brake, wherein the motor rotation angle is the motor rotation angle when the gap between the brake disc and the brake friction pad is eliminated;

[0045] The processing module is used to determine the piston travel of the electromechanical brake based on the motor rotation angle, the lead of the transmission element of the electromechanical brake, and the transmission ratio of the transmission mechanism, wherein the transmission element is the transmission element between the transmission mechanism and the piston; determine the first caliper clamping force of the electromechanical brake based on the piston travel and a pre-calibrated target correspondence table, wherein the target correspondence table includes the correspondence between the caliper calibration clamping force and the piston calibration travel; and determine the estimated caliper clamping force of the electromechanical brake based on the first caliper clamping force of the electromechanical brake.

[0046] Thirdly, a controller is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the steps of the electromechanical brake clamping force estimation method as described in any of the preceding claims.

[0047] Fourthly, a vehicle is provided, the vehicle including an electromechanical brake and the aforementioned controller.

[0048] Fifthly, a computer-readable storage medium is provided, the computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the electromechanical brake clamping force estimation method as described in any of the preceding claims.

[0049] In summary, this application proposes a method, device, controller, vehicle, and medium for estimating the clamping force of an electromechanical brake. By acquiring the motor rotation angle of the electromechanical brake, and based on the motor rotation angle, the lead of the transmission element of the electromechanical brake, and the transmission ratio of the transmission mechanism, the piston travel of the electromechanical brake is determined. According to a pre-calibrated target correspondence table of the piston travel, the first caliper clamping force of the electromechanical brake is determined. Based on the first caliper clamping force, the estimated caliper clamping force of the electromechanical brake is determined. It is evident that this application utilizes the characteristics of electromechanical brake products. By using the motor rotation angle signal of the electromechanical brake to calculate the piston travel, and then determining the first caliper clamping force of the electromechanical brake according to the piston travel and pre-calibrated target correspondence table, the clamping force of the brake is ultimately calculated. This eliminates the need for additional mechanical mechanisms and sensors, reducing both the overall size and cost of the electromechanical brake. Attached Figure Description

[0050] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a schematic diagram of the structure of an electromechanical brake according to one embodiment of this application;

[0052] Figure 2 This is a flowchart illustrating a method for estimating the clamping force of an electromechanical brake according to one embodiment of this application;

[0053] Figure 3 This is a schematic diagram of the disc clearance structure of an electromechanical brake according to one embodiment of this application;

[0054] Figure 4 This is a schematic diagram illustrating the relationship between piston stroke and clamping force in an electromechanical brake clamping force estimation method according to an embodiment of this application;

[0055] Figure 5 This is another flowchart illustrating a method for estimating the clamping force of an electromechanical brake according to one embodiment of this application;

[0056] Figure 6 This is another flowchart illustrating a method for estimating the clamping force of an electromechanical brake according to one embodiment of this application;

[0057] Figure 7 This is a schematic diagram of a device for estimating the clamping force of an electromechanical brake according to one embodiment of this application;

[0058] Figure 8 This is a schematic diagram of the structure of a controller according to one embodiment of this application;

[0059] Explanation of reference numerals in the attached figures:

[0060] 1. Motor; 2. Gear transmission mechanism; 3. Ball screw; 4. Piston; 5. Friction plate; 6. Brake disc; 7. Caliper body. Detailed Implementation

[0061] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0062] In some related technologies, electromechanical brakes in vehicles use pressure sensors of various shapes directly mounted within the brake for clamping force measurement. This testing method has several drawbacks: high installation requirements for built-in sensors; high cost of suitable small and accurate force sensors; difficulty in arranging electrical signal harnesses within the electromechanical brake; and the built-in sensors, being close to the brake disc, are susceptible to temperature changes, affecting the overall vehicle control accuracy and safety, leading to decreased measurement accuracy. Therefore, this invention, to meet the needs of electromechanical brakes, provides a method for estimating the clamping force of electromechanical brakes. By utilizing the motor rotation angle signal and / or motor current signal of the electromechanical brake, the clamping force is calculated, freeing the electromechanical brake from dependence on built-in sensors, reducing the overall size and cost of the electromechanical brake, and thus improving the accuracy of clamping force estimation.

[0063] In some embodiments, such as Figure 1 As shown, Figure 1This is a schematic diagram of an electromechanical brake used in an embodiment of this application. The electromechanical brake mainly includes: 1. a motor; 2. a gear transmission mechanism; 3. a ball screw; 4. a piston; 5. friction pads; 6. a brake disc; and 7. a caliper body. When the EMB motor 1 receives a braking signal from the controller, it rotates, driving the gear transmission mechanism 2 to rotate. The rotation of the gear transmission mechanism 2 drives the lead screw in the ball screw 3 to rotate. The rotation of the lead screw pushes the piston 4 forward, and the piston 4 pushes the friction pads 5 towards the brake disc 6, thereby clamping the brake disc 6. When clamping the brake disc 6, the pressure value of the caliper body 7 changes with the clamping force, thus generating braking force. The controller can then accurately estimate the clamping force of the electromechanical brake. This application eliminates the need for additional hardware and sensors, facilitating the placement of the electromechanical brake on the vehicle, reducing both the overall size and cost of the electromechanical brake. It should be noted that the ball screw in this application is equivalent to a transmission element, but other elements can also be used as transmission elements, and this application does not impose any limitations on this.

[0064] In this embodiment, since the friction plate 5 and piston 4 are separate, and the displacement of piston 4 has a strong correlation with the motor rotation angle, while the correlation of friction plate 5 is not strong, especially during return to its original position, there is no correlation when eliminating disc-plate gap. Therefore, the displacement of piston 4 is more accurate for estimating clamping force. Furthermore, during vehicle braking, the kinetic energy of the entire vehicle is converted into heat energy of the brake disc, causing the temperature of brake disc 6 to rise. The measurement accuracy of the sensor is greatly affected by the temperature of the brake disc, which in turn affects the control accuracy of the entire vehicle and its safety. Therefore, by removing additional mechanical mechanisms and sensors in the electromechanical brake, the temperature of brake disc 6 no longer affects the sensor measurement. Instead, the clamping force of the brake is directly calculated using the motor rotation angle signal and / or motor current signal of the electromechanical brake, thereby improving the accuracy of the electromechanical brake in estimating clamping force.

[0065] It should be noted that the above Figure 1 This is merely a schematic diagram of one system configuration used in the electromechanical brake clamping force estimation method provided in this application embodiment, and does not limit the system configuration of the automobile in which the electromechanical brake clamping force estimation method provided in this application embodiment is used.

[0066] In some embodiments, such as Figure 2 The diagram shown is a flowchart illustrating a method for estimating the clamping force of an electromechanical brake according to an embodiment of the present invention. This method is applied to... Figure 1 Taking the electromechanical brake as an example, the method for estimating the clamping force of the electromechanical brake may include the following steps:

[0067] S10A: Obtain the motor rotation angle of the electromechanical brake, wherein the motor rotation angle is the motor rotation angle when the gap between the brake disc and the brake friction pad is eliminated.

[0068] S20A: The piston travel of the electromechanical brake is determined based on the motor rotation angle, the lead of the transmission element of the electromechanical brake, and the transmission ratio of the transmission mechanism. The transmission element is the transmission element between the transmission mechanism and the piston.

[0069] S30A: Determine the first caliper clamping force of the electromechanical brake according to the piston travel stroke and the pre-calibrated target correspondence table, wherein the target correspondence table includes the correspondence between the calibrated clamping force of the caliper and the calibrated travel stroke of the piston.

[0070] S40A: Determine the estimated caliper clamping force of the electromechanical brake based on the first caliper clamping force of the electromechanical brake.

[0071] This embodiment provides a method for estimating the clamping force of an electromechanical brake, which can be executed by an automotive controller. Since the motors used in electromechanical brakes are generally brushless DC motors or permanent magnet synchronous motors, these motors integrate rotor angle and position sensors, enabling accurate acquisition of rotor speed and angle changes. Since the motor's angle position has a certain correlation with the caliper's clamping force, when the controller sends a target command to estimate the caliper's clamping force, the motor rotates. At this time, the motor angle of the electromechanical brake is acquired, and the brake clamping force is calculated using the motor angle signal.

[0072] In this embodiment, wear of the friction pads leads to an increase in disc clearance, which alters the caliper clamping force and piston travel characteristics, affecting the accuracy of clamping force estimation. Therefore, based on the operating characteristics of the motor and the EMB electromechanical brake, the motor rotation pushes the piston forward. When disc clearance appears, the friction pads contact the brake disc, causing a sharp increase in motor load and a significant rise in motor current. The rate of change of motor current is then used to determine when the disc clearance is eliminated, thus obtaining the motor rotation angle at which the clearance between the brake disc and brake friction pads in the electromechanical brake is eliminated. The elimination of the disc clearance is described as follows: Figure 3 As shown. Compared to the above embodiment, determining whether the disc gap has been eliminated includes: when the rate of change of the motor current of the electromechanical brake is greater than or equal to a preset rate of change threshold, determining that the gap between the brake disc and the brake friction pad has been eliminated; when the rate of change of the motor current is less than the preset rate of change threshold, determining that the gap between the brake disc and the brake friction pad has not been eliminated.

[0073] As can be seen, in this embodiment, based on the physical characteristics of the caliper, the clamping force and piston travel characteristics of the caliper after eliminating the disc-plate gap are not affected by the wear of the friction pads (disc-plate gap). Therefore, an accurate comparison relationship can be measured on a test bench. This correspondence can be preset in the system (i.e., the correspondence between the caliper's calibrated clamping force and the piston's calibrated travel) and obtained through linear interpolation. Therefore, to eliminate this influence, it is necessary to accurately estimate the disc-plate contact point to eliminate estimation errors caused by disc-plate gap changes. During the clamping process, when eliminating the brake gap, the system has no clamping force, and the motor current fluctuates within the idle travel range. Only when the rate of change of the motor current of the electromechanical brake is greater than or equal to a preset rate of change threshold can it be determined that the gap between the brake disc and the brake friction pad has been eliminated, thereby obtaining the motor rotation angle at the time of gap elimination in the electromechanical brake. It is evident that eliminating disc clearance during clamping can increase braking pressure on this road surface, thereby reducing the error in estimating clamping force during braking. This ensures the accuracy of obtaining the motor rotation angle of the electromechanical brake, and allows the clamping force of the electromechanical brake to be calculated directly using a characteristic of the motor rotation angle.

[0074] It should be noted that the preset rate of change threshold can be an empirical value or a calibration value, depending on the actual situation, and this application does not impose any restrictions on it.

[0075] Based on the above embodiments, after obtaining the motor rotation angle of the electromechanical brake, the piston travel of the electromechanical brake is determined according to the motor rotation angle, the lead of the transmission element of the electromechanical brake, and the transmission ratio of the transmission mechanism. The transmission element is the transmission element between the transmission mechanism and the piston in the electromechanical brake. This application takes a ball screw as an example, and determines the motor rotation angle based on the ball screw rotation angle and the transmission ratio of the transmission mechanism. The formula relating the motor rotation angle and the ball screw rotation angle is as follows:

[0076] θ 电机 =i×θ 输出 (1)

[0077] Where, θ 电机 Represented as motor rotation angle; θ 输出 Let represent the ball screw rotation angle; i represents the transmission ratio of the transmission mechanism. This application determines the piston stroke by utilizing the ball screw rotation angle and the ball screw lead. The formula relating the ball screw rotation angle and the piston stroke is as follows:

[0078]

[0079] Where L represents the lead of the ball screw; θ 输出X represents the ball screw rotation angle; X represents the piston stroke. Then, based on formulas (1) and (2), the relationship between the piston stroke and the motor rotation angle is determined, and the calculation formula is as follows:

[0080]

[0081] Where, θ 电机 X represents the motor rotation angle, L represents the piston travel stroke, and i represents the transmission element lead.

[0082] After the piston travels in the electromechanical brake, the first caliper clamping force of the electromechanical brake is determined according to a pre-calibrated target correspondence table of the piston travel. This includes: querying the target correspondence table for the caliper calibration clamping force corresponding to the piston travel; if the caliper calibration clamping force corresponding to the piston travel is found, the found caliper calibration clamping force is the first caliper clamping force; if the caliper calibration clamping force corresponding to the piston travel is not found, the caliper calibration clamping force adjacent to the piston travel is retrieved from the target correspondence table, and interpolation is performed on the adjacent caliper calibration clamping force to obtain the first caliper clamping force.

[0083] As can be seen, in this embodiment, the pre-calibrated target correspondence table represents the correspondence between the calibrated clamping force of the calibrated calibrated piston travel, such as... Figure 4 As shown, the clamping force and calibrated values ​​of the caliber under different piston strokes are experimentally calibrated in advance and recorded in a correspondence table. The calibrated clamping force of the caliber corresponding to the piston stroke is retrieved from the pre-calibrated target correspondence table. When the calibrated clamping force corresponding to the piston stroke is found, the retrieved calibrated clamping force is the first caliber clamping force. When the calibrated clamping force corresponding to the piston stroke is not found, the calibrated clamping force of the caliber adjacent to the piston stroke is retrieved from the target correspondence table. The adjacent calibrated clamping forces are interpolated to obtain the first caliber clamping force. The interpolation can be performed using simple linear interpolation or more complex interpolation methods based on the clamping force values ​​corresponding to adjacent piston strokes. This application does not impose any limitations on this. As can be seen, after interpolating the clamping forces of adjacent calipers, it is not necessary to calibrate many values ​​in the target correspondence table. This allows for quick and accurate lookup of the clamping forces of calipers near the piston stroke from the target correspondence table, thereby improving the efficiency of calculating the clamping force of electromechanical brakes.

[0084] As can be seen, this application provides a control scheme for estimating the clamping force of an electromechanical brake by utilizing the motor rotation angle. By determining the piston travel of the electromechanical brake based on the motor rotation angle, the lead of the transmission element of the electromechanical brake, and the transmission ratio of the transmission mechanism, the first caliper clamping force of the electromechanical brake is calculated according to a pre-calibrated target correspondence table. This effectively prevents the electromechanical braking system from becoming detached from its reliance on built-in sensors, achieving the estimation of the brake clamping force without additional mechanical mechanisms and sensors. This not only reduces the overall size of the electromechanical brake but also lowers its overall cost. Furthermore, the estimated clamping force is less susceptible to temperature influences, thereby improving the accuracy of the estimated clamping force.

[0085] Furthermore, such as Figure 5 The diagram shown is another flowchart illustrating a method for estimating the clamping force of an electromechanical brake according to an embodiment of the present invention, which is applied to... Figure 1 Taking the electromechanical brake as an example, the method for estimating the clamping force of the electromechanical brake may include the following steps:

[0086] S10B: Determine the electromagnetic torque of the motor based on the motor torque coefficient and motor current of the electromechanical brake;

[0087] S20B: Calculate the second caliper clamping force of the electromechanical brake based on the electromagnetic torque of the motor, the lead of the transmission element, and the efficiency of the transmission element. The second caliper clamping force is the estimated caliper clamping force of the electromechanical brake.

[0088] In this embodiment, the clamping force calculated from the current is inaccurate during motor acceleration and deceleration. Therefore, the clamping force is only accurately calculated when the motor current is at low speed or stalled. Thus, the clamping force cannot be calculated simply by observing the presence of current; it needs to be calculated under appropriate operating conditions. When the control sends the target command to estimate the clamping force of the electromechanical brake, the motor rotates. At this time, the motor speed of the electromechanical brake is acquired. When the motor speed is less than the preset speed, the influence of rotational inertia and viscous resistance on the system is negligible and constant during uniform motor rotation or stall. The electromagnetic torque of the motor can be calculated from the motor current of the electromechanical brake, and then the clamping force of the brake can be calculated based on the electromagnetic torque. Therefore, by using the end of a braking operation, i.e., selecting a point close to the clamping brake disc approaching the motor stall or stalling, the motor current recorded within a preset time period before or during the stall of the electromechanical brake is acquired, and the clamping force of the caliper is calculated. Because the motor is affected by the system's rotational inertia and viscous resistance during rapid acceleration and deceleration, this application requires obtaining the motor current recorded during or within a preset time before the electromechanical brake stalls. At this time, the influence of the system's rotational inertia and viscous resistance is small and negligible, and is a constant, so the caliper clamping force can be calculated quickly and accurately.

[0089] In this embodiment, the motor torque coefficient is typically a known parameter, and the motor current can be measured by the motor control system. The electromagnetic torque of the motor is determined based on the motor torque coefficient and motor current of the electromechanical brake. The relationship between the motor torque coefficient and motor current is as follows:

[0090] T 电机 =KT×I (4)

[0091] Where KT represents the motor torque coefficient; I represents the motor current; T 电机 This is expressed as the electromagnetic torque of the motor. The relationship between the electromagnetic torque of the motor and the output torque of the gear transmission mechanism is given by the following formula:

[0092]

[0093] Where J represents the system's moment of inertia; Expressed as the motor angular velocity; T 负载 T represents the output torque of the transmission mechanism. 摩擦 T is expressed as the frictional torque of the system. 粘滞 This is expressed as the viscous torque of the system, i.e., T. 粘滞 =K×ω, where K represents the viscosity coefficient and ω represents the motor speed.

[0094] In this embodiment, after obtaining the relationship between the motor torque coefficient and the motor current, as well as the relationship between the motor electromagnetic torque and the output torque of the gear transmission mechanism, the second caliper clamping force of the electromechanical brake is determined based on the lead of the ball screw, the ball screw efficiency, and the output torque of the transmission mechanism. The formula relating the caliper clamping force to the output torque of the gear transmission mechanism is as follows:

[0095]

[0096] Where L represents the lead of the ball screw; η1 represents the efficiency of the ball screw. Here, the ball screw is equivalent to a transmission element. Then, based on the electromagnetic torque of the motor, the lead of the transmission element, and the efficiency of the transmission element, i.e., according to formulas (4), (5), and (6), the clamping force of the second caliper of the electromechanical brake is calculated. The formula for calculating the clamping force of the second caliper of the electromechanical brake is as follows:

[0097]

[0098] Where F2 represents the clamping force of the second caliper, KT represents the motor torque coefficient, I represents the motor current, and T... 摩擦 Let represent the system friction torque of the electromechanical brake, L represent the lead of the transmission element, η1 represent the efficiency of the transmission element, and J represent the system moment of inertia of the electromechanical brake. Expressed as the motor angular velocity, T 粘滞 It is expressed as the viscous torque of an electromechanical brake.

[0099] Compared to the above embodiments, when the motor is rotating at a constant speed or stalled, the system is less affected by rotational inertia and viscous resistance. and T 粘滞 The simplified formula relating caliper clamping force to motor current is negligible and can be used to determine the relationship:

[0100]

[0101] Where F2 represents the clamping force of the second caliper, KT represents the motor torque coefficient, I represents the motor current, and T... 摩擦 Let L represent the system friction torque of the electromechanical brake, L represent the lead of the transmission element, and η1 represent the efficiency of the transmission element.

[0102] As can be seen, this application provides a control scheme for estimating the clamping force of an electromechanical brake by utilizing the motor rotation angle of the electromechanical brake. By determining the electromagnetic torque of the motor based on the motor torque coefficient and motor current of the electromechanical brake, and then calculating the clamping force of the second caliper of the electromechanical brake based on the electromagnetic torque of the motor, the lead of the transmission element, and the efficiency of the transmission element, the clamping force of the brake is finally estimated. This effectively prevents the electromechanical braking system from becoming detached from its dependence on built-in sensors, and achieves the estimation of the clamping force of the brake without additional mechanical mechanisms and sensors. This not only reduces the overall size of the electromechanical brake, but also lowers the overall cost of the electromechanical brake. Furthermore, the estimated clamping force is no longer easily affected by temperature, thereby improving the accuracy of the estimated clamping force of the electromechanical brake.

[0103] In some embodiments, such as Figure 6 The diagram shown is a flowchart illustrating a method for estimating the clamping force of an electromechanical brake according to an embodiment of the present invention. This method is applied to... Figure 1 Taking the electromechanical brake as an example, the method for estimating the clamping force of the electromechanical brake may include the following steps:

[0104] S10C: Calculate the piston travel of the electromechanical brake based on the motor rotation angle, transmission element lead, and transmission ratio of the transmission mechanism, and determine the first caliper clamping force of the electromechanical brake based on the correspondence between the piston travel and the pre-calibrated target table.

[0105] S20C: Determine the electromagnetic torque of the electromechanical brake based on the motor current and motor torque coefficient, and calculate the second caliper clamping force of the electromechanical brake based on the electromagnetic torque of the motor, the lead of the transmission element and the efficiency of the transmission element.

[0106] S30C: Perform a weighted average of the first caliper clamping force and the second caliper clamping force to obtain the estimated caliper clamping force of the electromechanical brake.

[0107] In this embodiment, due to the influence of system rotational inertia and viscous resistance during rapid acceleration and deceleration, the accuracy of directly estimating the caliper clamping force using the second caliper clamping force obtained from the motor current is not high. Therefore, when the control sends the target command to execute the estimated caliper clamping force of the electromechanical brake, the motor rotates. At this time, this embodiment also calculates the piston travel of the electromechanical brake based on the motor rotation angle, the lead of the transmission element, and the transmission ratio of the transmission mechanism. Based on the correspondence between the piston travel and the pre-calibrated target, the first caliper clamping force of the electromechanical brake is determined. After determining the first caliper clamping force, the electromagnetic torque of the electromechanical brake is determined based on the motor current and the motor torque coefficient. Based on the electromagnetic torque, the lead of the transmission element, and the efficiency of the transmission element, the second caliper clamping force of the electromechanical brake is calculated. After obtaining the second caliper clamping force, the estimated caliper clamping force of the electromechanical brake is determined by weighted averaging the first caliper clamping force obtained from the motor rotation angle and the second caliper clamping force obtained from the motor current. The weighted averaging process for the clamping forces of the first and second calipers includes: calculating a clamping force error coefficient, whereby the clamping force evaluation coefficient represents the difference between the clamping forces of the first and second calipers; when the clamping force error coefficient is greater than a preset coefficient threshold, a brake fault alarm is output; when the clamping force error coefficient is less than or equal to the preset coefficient threshold, a weighted averaging process is performed on the clamping forces of the first and second calipers to obtain the estimated clamping force of the electromechanical brake.

[0108] As can be seen, in this embodiment, the clamping force error coefficient between the clamping force of the first caliper and the clamping force of the second caliper is calculated. The formula for calculating the clamping force error coefficient is as follows:

[0109]

[0110] Where σ represents the clamping force error coefficient; F2 represents the clamping force of the second caliper; and F1 represents the clamping force of the first caliper. This application pre-sets a coefficient threshold and compares the clamping force error coefficient with this threshold. When the clamping force error coefficient is greater than the threshold, a brake fault alarm is output. When the clamping force error coefficient is less than or equal to the threshold, a weighted average is applied to the clamping forces of the first and second calipers to obtain the estimated clamping force of the electromechanical brake. This application uses the difference between the calculated clamping forces of the first and second calipers, i.e., the clamping force error coefficient, for parameter self-correction fuzzy control. The obtained clamping force of the second caliper is compared and verified with the clamping force of the first caliper, thereby improving the accuracy and reliability of the clamping force estimation. The range of the control quantity u used for correction only plays a minor adjustment role in the overall system regulation, resulting in higher control precision and better adaptability.

[0111] The formula for calculating the weighted average of the clamping forces of the first and second calipers is as follows:

[0112]

[0113] Where N1 + N2 = 1, N1 represents the weight of the clamping force of the first caliper; N2 represents the weight of the clamping force of the second caliper; and F3 represents the estimated clamping force of the electromechanical brake. During the increasing braking force phase, the weight N2 is greater than the weight N1, and the clamping force F2 calculated based on the motor current I has higher reliability; therefore, a larger weight N2 is assigned. During the maintaining and decreasing braking force phases, the weight N1 is greater than the weight N2, determined by the motor rotation angle θ. 电机 The estimated clamping force F1 has higher reliability; therefore, a larger weight N1 is assigned. This application achieves a more accurate estimated caliper clamping force for the electromechanical brake by weighted averaging the clamping forces of the first and second calipers. This reflects the overall cost of the electromechanical brake, thereby improving the accuracy and efficiency of the estimated caliper clamping force. It should be noted that the preset coefficient threshold and weights can be set according to actual conditions and can be empirical or calibrated values; this application does not impose any limitations on this.

[0114] As can be seen, this application provides a control scheme for estimating the clamping force of an electromechanical brake using the motor current and motor rotation angle. The scheme calculates the piston travel of the electromechanical brake based on the motor rotation angle, transmission element lead, and transmission ratio of the transmission mechanism. Then, based on a pre-calibrated target correspondence table, the first caliper clamping force of the electromechanical brake is determined. Next, the motor electromagnetic torque is determined based on the motor torque coefficient and motor current. Finally, the second caliper clamping force of the electromechanical brake is calculated based on the motor electromagnetic torque, transmission element lead, and transmission element efficiency. Based on the first and second caliper clamping forces, the clamping force of the brake is ultimately estimated. The second caliper clamping force is compared and verified with the first caliper clamping force, thereby further improving the accuracy and reliability of the caliper clamping force estimation.

[0115] It should be noted that, in conjunction with the above embodiments, the embodiments of this application use three control methods to calculate the clamping force of the electromechanical brake: the motor rotation angle signal and / or the motor current signal of the electromechanical brake. This eliminates the need for built-in sensors, reducing the overall size of the electromechanical brake, facilitating its layout, and eliminating the influence of brake disc temperature. This improves the accuracy of the electromechanical brake in estimating the clamping force and enhances vehicle safety.

[0116] In summary, this application proposes a method, device, controller, vehicle, and medium for estimating the clamping force of an electromechanical brake. By acquiring the motor rotation angle of the electromechanical brake, and based on the motor rotation angle, the lead of the transmission element of the electromechanical brake, and the transmission ratio of the transmission mechanism, the piston travel of the electromechanical brake is determined. According to a pre-calibrated target correspondence table of the piston travel, the first caliper clamping force of the electromechanical brake is determined. Based on the first caliper clamping force, the estimated caliper clamping force of the electromechanical brake is determined. It is evident that this application utilizes the characteristics of electromechanical brake products. By using the motor rotation angle signal of the electromechanical brake to calculate the piston travel, and then determining the first caliper clamping force of the electromechanical brake according to the piston travel and pre-calibrated target correspondence table, the clamping force of the brake is ultimately calculated. This eliminates the need for additional mechanical mechanisms and sensors, reducing both the overall size and cost of the electromechanical brake.

[0117] It should be understood that the sequence number of each step in the above embodiments does not 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 this application.

[0118] In one embodiment, an electromechanical brake clamping force estimation device is provided, which corresponds one-to-one with the electromechanical brake clamping force estimation method described in the above embodiments. For example... Figure 7 As shown, the electromechanical brake clamping force estimation device includes an acquisition module 101 and a processing module 102. Detailed descriptions of each functional module are as follows:

[0119] The acquisition module 101 is used to acquire the motor rotation angle of the electromechanical brake, wherein the motor rotation angle is the motor rotation angle when the gap between the brake disc and the brake friction pad is eliminated;

[0120] The processing module 102 is used to determine the piston travel of the electromechanical brake based on the motor rotation angle, the lead of the transmission element of the electromechanical brake, and the transmission ratio of the transmission mechanism, wherein the transmission element is the transmission element between the transmission mechanism and the piston; determine the first caliper clamping force of the electromechanical brake based on the piston travel and a pre-calibrated target correspondence table, wherein the target correspondence table includes the correspondence between the caliber clamping force and the piston caliber travel; and determine the estimated caliper clamping force of the electromechanical brake based on the first caliper clamping force of the electromechanical brake.

[0121] In one embodiment, the acquisition module 101 is further configured to:

[0122] When the rate of change of the motor current of the electromechanical brake is greater than or equal to a preset rate of change threshold, it is determined that the gap between the brake disc and the brake friction pad is eliminated.

[0123] When the rate of change of the motor current is less than a preset rate of change threshold, it is determined that the gap between the brake disc and the brake friction pad has not been eliminated.

[0124] In one embodiment, the processing module 102 is further configured to:

[0125] The piston stroke of the electromechanical brake is calculated using the following formula:

[0126]

[0127] Where, θ 电机 X represents the motor rotation angle, L represents the piston travel stroke, and i represents the transmission element lead.

[0128] In one embodiment, the processing module 102 is further configured to:

[0129] Query the caliper clamping force corresponding to the piston travel stroke from the target mapping table;

[0130] When the caliper calibration clamping force corresponding to the piston travel stroke is found, the found caliper calibration clamping force is the first caliper clamping force;

[0131] If the caliper calibration clamping force corresponding to the piston movement stroke is not found, the caliper calibration clamping force adjacent to the piston movement stroke is retrieved from the target correspondence table, and the adjacent caliper calibration clamping force is interpolated to obtain the first caliper clamping force.

[0132] In one embodiment, the processing module 102 is further configured to:

[0133] The first caliper clamping force is the estimated caliper clamping force;

[0134] or;

[0135] The estimated caliper clamping force of the electromechanical brake is determined based on the first caliper clamping force and the second caliper clamping force of the electromechanical brake, wherein the second caliper clamping force is calculated based on the motor current of the electromechanical brake.

[0136] In one embodiment, the processing module 102 is further configured to:

[0137] The electromagnetic torque of the motor is determined based on the motor torque coefficient and motor current of the electromechanical brake.

[0138] The second caliper clamping force of the electromechanical brake is calculated based on the electromagnetic torque of the motor, the lead of the transmission element, and the efficiency of the transmission element.

[0139] In one embodiment, the processing module 102 is further configured to:

[0140] The motor current is the motor current recorded when the motor is stalled or within a preset time period before stalling.

[0141] In one embodiment, the processing module 102 is further configured to:

[0142] The second caliper clamping force of the electromechanical brake is calculated using the following formula:

[0143]

[0144] Where F2 represents the clamping force of the second caliper, KT represents the motor torque coefficient, I represents the motor current, and T 摩擦 The system friction torque of the electromechanical brake is represented by L, the lead of the transmission element is represented by η1, and the efficiency of the transmission element is represented by η1.

[0145] In one embodiment, the processing module 102 is further configured to:

[0146] The second caliper clamping force of the electromechanical brake is calculated using the following formula:

[0147]

[0148] Where F2 represents the clamping force of the second caliper, KT represents the motor torque coefficient, I represents the motor current, and T 摩擦 Let L represent the system friction torque of the electromechanical brake, L represent the lead of the transmission element, η1 represent the efficiency of the transmission element, and J represent the system moment of inertia of the electromechanical brake. T represents the angular velocity of the motor. 粘滞 This represents the viscous torque of the electromechanical brake.

[0149] In one embodiment, the processing module 102 is further configured to:

[0150] The clamping forces of the first caliper and the second caliper are weighted and averaged to obtain the estimated clamping force of the electromechanical brake.

[0151] In one embodiment, the processing module 102 is further configured to:

[0152] The clamping force error coefficient is calculated, and the clamping force evaluation coefficient represents the difference between the clamping force of the first caliper and the clamping force of the second caliper.

[0153] If the clamping force error coefficient is greater than the preset coefficient threshold, a braking fault alarm will be output.

[0154] When the clamping force error coefficient is less than or equal to the preset coefficient threshold, the first caliper clamping force and the second caliper clamping force are weighted and averaged to obtain the estimated caliper clamping force of the electromechanical brake.

[0155] As can be seen, this application provides an electromechanical brake clamping force estimation device. By utilizing the characteristics of electromechanical brake products, it eliminates the need for additional mechanical mechanisms and sensors. By using the motor rotation angle, transmission element lead, and transmission ratio of the electromechanical brake, the piston travel is calculated. Then, based on the correspondence between the piston travel and a pre-calibrated target table, the first caliper clamping force of the electromechanical brake is determined, ultimately realizing the estimation of the brake's clamping force and thus improving the accuracy of the electromechanical brake's clamping force estimation.

[0156] For specific limitations regarding the electromechanical brake clamping force estimation device, please refer to the limitations on the electromechanical brake clamping force estimation method mentioned above, which will not be repeated here. Each module in the aforementioned electromechanical brake clamping force estimation device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the electronic device in hardware form or independently of it, or they can be stored in the memory of the electronic device in software form, so that the processor can call and execute the corresponding operations of each module.

[0157] In one embodiment, a controller is provided, the internal structure of which can be shown in the diagram below. Figure 8 As shown, the controller includes a processor, memory, and a network interface connected via a system bus. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The processor's network interface is used to communicate with other automotive components via a network connection to send relevant control parameters. When executed by the processor, the computer program implements a method for estimating the clamping force of an electromechanical brake.

[0158] In one embodiment, a controller is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the electromechanical brake clamping force estimation method as provided in any embodiment of this application.

[0159] In one embodiment, a vehicle is provided, the vehicle including an electromechanical brake and the aforementioned controller.

[0160] In one embodiment, a computer-readable storage medium is provided, the computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the electromechanical brake clamping force estimation method provided in any of the embodiments of this application.

[0161] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0162] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0163] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for estimating the clamping force of an electromechanical brake, characterized in that, include: The motor rotation angle of the electromechanical brake is obtained, and the motor rotation angle is the motor rotation angle when the gap between the brake disc and the brake friction pad is eliminated; The piston stroke of the electromechanical brake is determined based on the motor rotation angle, the lead of the transmission element of the electromechanical brake, and the transmission ratio of the transmission mechanism. The transmission element is the transmission element between the transmission mechanism and the piston. The first caliper clamping force of the electromechanical brake is determined according to the piston travel stroke and the pre-calibrated target correspondence table, wherein the target correspondence table includes the correspondence between the calibrated clamping force of the caliper and the calibrated travel stroke of the piston. The estimated caliper clamping force of the electromechanical brake is determined based on the first caliper clamping force of the electromechanical brake.

2. The method for estimating the clamping force of an electromechanical brake as described in claim 1, characterized in that, The step of determining the first caliper clamping force of the electromechanical brake based on the correspondence between the piston travel and a pre-calibrated target table includes: Query the caliper clamping force corresponding to the piston travel stroke from the target mapping table; When the caliper calibration clamping force corresponding to the piston travel stroke is found, the found caliper calibration clamping force is the first caliper clamping force; If the caliper calibration clamping force corresponding to the piston movement stroke is not found, the caliper calibration clamping force adjacent to the piston movement stroke is retrieved from the target correspondence table, and the adjacent caliper calibration clamping force is interpolated to obtain the first caliper clamping force.

3. The method for estimating the clamping force of an electromechanical brake as described in claim 1, characterized in that, The step of determining the piston stroke of the electromechanical brake based on the motor rotation angle, the lead of the transmission element of the electromechanical brake, and the transmission ratio of the transmission mechanism includes: The piston stroke of the electromechanical brake is calculated using the following formula: Where, θ 电机 X represents the motor rotation angle, L represents the piston travel stroke, and i represents the transmission element lead.

4. The method for estimating the clamping force of an electromechanical brake as described in claim 2, characterized in that, Determine whether the gap between the brake disc and the brake friction pads has been eliminated using the following method: When the rate of change of the motor current of the electromechanical brake is greater than or equal to a preset rate of change threshold, it is determined that the gap between the brake disc and the brake friction pad is eliminated. When the rate of change of the motor current is less than a preset rate of change threshold, it is determined that the gap between the brake disc and the brake friction pad has not been eliminated.

5. The method for estimating the clamping force of an electromechanical brake as described in any one of claims 1-4, characterized in that, The step of determining the estimated caliper clamping force of the electromechanical brake based on the first caliper clamping force of the electromechanical brake includes: The first caliper clamping force is the estimated caliper clamping force; or; The estimated caliper clamping force of the electromechanical brake is determined based on the first caliper clamping force and the second caliper clamping force of the electromechanical brake, wherein the second caliper clamping force is calculated based on the motor current of the electromechanical brake.

6. The method for estimating the clamping force of an electromechanical brake as described in claim 5, characterized in that, The clamping force of the second caliper is determined in the following manner: The electromagnetic torque of the motor is determined based on the motor torque coefficient and motor current of the electromechanical brake. The second caliper clamping force of the electromechanical brake is calculated based on the electromagnetic torque of the motor, the lead of the transmission element, and the efficiency of the transmission element.

7. The method for estimating the clamping force of an electromechanical brake as described in claim 6, characterized in that, The motor current is the motor current recorded when the motor is stalled or within a preset time period before stalling.

8. The method for estimating the clamping force of an electromechanical brake as described in claim 7, characterized in that, The calculation of the second caliper clamping force of the electromechanical brake based on the electromagnetic torque of the motor, the lead of the transmission element, and the efficiency of the transmission element includes: The second caliper clamping force of the electromechanical brake is calculated using the following formula: Where F2 represents the clamping force of the second caliper, KT represents the motor torque coefficient, I represents the motor current, and T 摩擦 The system friction torque of the electromechanical brake is represented by L, the lead of the transmission element is represented by η1, and the efficiency of the transmission element is represented by η1.

9. The method for estimating the clamping force of an electromechanical brake as described in claim 6, characterized in that, The calculation of the second caliper clamping force of the electromechanical brake based on the electromagnetic torque of the motor, the lead of the transmission element, and the efficiency of the transmission element includes: The second caliper clamping force of the electromechanical brake is calculated using the following formula: Where F2 represents the clamping force of the second caliper, KT represents the motor torque coefficient, I represents the motor current, and T 摩擦 Let L represent the system friction torque of the electromechanical brake, L represent the lead of the transmission element, η1 represent the efficiency of the transmission element, and J represent the system moment of inertia of the electromechanical brake. T represents the angular velocity of the motor. 粘滞 This represents the viscous torque of the electromechanical brake.

10. The method for estimating the clamping force of an electromechanical brake as described in claim 5, characterized in that, The step of determining the estimated caliper clamping force of the electromechanical brake based on the first caliper clamping force and the second caliper clamping force includes: The clamping forces of the first caliper and the second caliper are weighted and averaged to obtain the estimated clamping force of the electromechanical brake.

11. The method for estimating the clamping force of an electromechanical brake as described in claim 10, characterized in that, The step of weighted averaging the first caliper clamping force and the second caliper clamping force to obtain the estimated caliper clamping force of the electromechanical brake includes: The clamping force error coefficient is calculated, and the clamping force evaluation coefficient represents the difference between the clamping force of the first caliper and the clamping force of the second caliper. If the clamping force error coefficient is greater than the preset coefficient threshold, a braking fault alarm will be output. When the clamping force error coefficient is less than or equal to the preset coefficient threshold, the first caliper clamping force and the second caliper clamping force are weighted and averaged to obtain the estimated caliper clamping force of the electromechanical brake.

12. A device for estimating the clamping force of an electromechanical brake, characterized in that, include: The acquisition module is used to acquire the motor rotation angle of the electromechanical brake, wherein the motor rotation angle is the motor rotation angle when the gap between the brake disc and the brake friction pad is eliminated; The processing module is used to determine the piston travel of the electromechanical brake based on the motor rotation angle, the lead of the transmission element of the electromechanical brake, and the transmission ratio of the transmission mechanism, wherein the transmission element is the transmission element between the transmission mechanism and the piston; determine the first caliper clamping force of the electromechanical brake based on the piston travel and a pre-calibrated target correspondence table, wherein the target correspondence table includes the correspondence between the caliper calibration clamping force and the piston calibration travel; and determine the estimated caliper clamping force of the electromechanical brake based on the first caliper clamping force of the electromechanical brake.

13. A controller comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the electromechanical brake clamping force estimation method as described in any one of claims 1 to 11.

14. A car, characterized in that, The vehicle includes an electromechanical brake and a controller as described in claim 13.

15. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the electromechanical brake clamping force estimation method as described in any one of claims 1 to 11.

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