Electromechanical drive-by-wire brake, system, vehicle and clamping force estimation method

Abstract

The invention relates to an electronic mechanical drive-by-wire brake, system, vehicle and clamping force estimation method, a brake actuator comprises a support, and the support is provided with a brake block, a caliper body, a reverse planetary roller screw pair, a planetary gear reducer and a coreless axial flux motor. An eddy current type motor position sensor is fixedly arranged on the coreless axial flux motor; the coreless axial magnetic flux motor is matched with the planetary gear reducer to drive a lead screw of the reverse planetary roller lead screw pair to rotate so as to drive a lead screw nut of the reverse planetary roller lead screw pair to reciprocate on the support, and therefore the lead screw nut drives the brake block to reciprocate on the support. The eddy current type motor position sensor is used for detecting the rotation angle of the coreless axial flux motor; the device is high in integration level and small in installation space requirement.

Description

Technical Field

[0001] This invention relates to the field of vehicle brake-by-wire technology, specifically to an electromechanical brake-by-wire device, system, vehicle, and method for estimating clamping force. Background Technology

[0002] When a car is driving under different conditions, if deceleration is required, the driver presses the brake pedal. The brake pedal sensor on the electronic brake pedal detects braking signals such as pedal acceleration, displacement, and pedal force. The controller receives the braking command signal through the vehicle network, integrates other sensor signals related to the vehicle's current driving status, and combines them with a corresponding intention recognition algorithm to identify the driver's braking intention and calculate the optimal braking force required for each wheel. The four independently controlled braking modules receive signals from the controller to control the motor speed to achieve torque response, and then control the electromechanical brakes to generate the corresponding braking force to achieve braking. The biggest advantage of electromechanical braking technology is its rapid response. A typical EMB actuator mainly consists of a motor, a reduction and torque amplification mechanism, and a motion conversion mechanism.

[0003] A typical electromechanical brake uses a ball screw paired with a planetary gear reducer. A permanent magnet DC torque motor receives control signals from the EMB controller and outputs torque. The planetary gear reducer converts the high-speed, low-torque motion of the motor into low-speed, high-torque motion. The ball screw then converts the rotary motion into linear motion, pushing the brake pads to press against the brake disc and generate the target braking force. Existing EMB actuators have the following drawbacks: ① Radial flux motors have lower magnetic flux density. For the same output torque, the stator and rotor of the motor are larger, the moment of inertia is larger, and the response is slower. This affects the system response speed and requires more installation space, which makes installation difficult. ② The signal quality of the Hall effect sensor TMR used for motor position signal acquisition and control is greatly affected by vibration and temperature drift, which directly affects the motor control accuracy and thus the vehicle braking performance; ③ Under alternating positive and negative impact loads, ball screws are prone to stress corrosion, which shortens their lifespan and causes abnormal noise, leading to premature system failure. Summary of the Invention

[0004] To address the technical problems of large size of EMB actuators in existing technologies, this invention provides an electromechanical wire-controlled brake, system, vehicle, and clamping force estimation method.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: An electromechanical linear control brake actuator is characterized in that it includes a bracket, on which a brake block, a clamp body, a reverse planetary roller screw pair, a planetary gear reducer and a coreless axial flux motor are provided, and an eddy current type motor position sensor is fixedly provided on the coreless axial flux motor. The motor shaft of the coreless axial flux motor is a hollow shaft. The planetary gear reducer is located inside the motor shaft. The motor shaft is connected to the reducer input shaft of the planetary gear reducer. The reducer output shaft of the planetary gear reducer is connected to the lead screw of the inverse planetary roller screw pair. The lead screw nut of the inverse planetary roller screw pair is connected to the brake block. The coreless axial flux motor, in conjunction with the planetary gear reducer, drives the lead screw of the inverted planetary roller screw pair to rotate, thereby driving the lead screw nut of the inverted planetary roller screw pair to reciprocate on the bracket, which in turn drives the brake block to reciprocate on the bracket; the eddy current type motor position sensor is used to detect the rotation angle of the coreless axial flux motor.

[0006] The beneficial effects of this invention are: it adopts a coreless hollow shaft axial flux motor, which has high magnetic flux density, no iron loss, line loss and heat generation, and an efficiency of over 95%; when outputting the same torque, the stator and rotor of the motor are smaller in size, the moment of inertia is smaller, the response is faster and the lag is smaller; it has high integration and requires less installation space.

[0007] Employing an eddy current motor position sensor, the signal exhibits strong resistance to stray magnetic field interference; it is also resistant to shock and vibration; resistant to high temperatures with minimal temperature drift and higher accuracy; it can achieve angular acceleration acquisition and control; a built-in temperature sensor allows for temperature compensation of the motor position; and it features both analog and digital signal interfaces, ensuring a high level of safety.

[0008] The reverse planetary roller screw has a larger contact surface and more stable force distribution, which will not cause stress concentration. It is especially advantageous for the intermittent impact load of EMB. Its average life is 11 times that of ball screws of the same specification, so that the screw life matches the life of the EMB system.

[0009] The lead screw nut is integrated with the piston of the traditional brake actuator, that is, the lead screw nut replaces the piston of the traditional brake actuator and directly pushes the brake block to brake the vehicle. The planetary gear reducer is placed in the hollow shaft of the motor, so that the planetary gear reducer and the motor are integrated into a whole component and mounted on the bracket, eliminating the alignment error of separate installation. The connecting structure is eliminated, reducing the failure points.

[0010] Based on the above technical solution, the present invention can be further improved as follows.

[0011] Furthermore, a lead screw mating hole is provided at one end of the lead screw nut, and the lead screw mating hole is rotatably connected to one end of the lead screw through a planetary roller. The lead screw mating hole is a countersunk hole. The other end of the lead screw nut is fixedly connected to the brake block.

[0012] Furthermore, the planetary gear reducer is a two-stage planetary gear reducer.

[0013] Furthermore, the two-stage planetary gear reducer includes a first-stage planetary gear pair, a second-stage planetary gear pair, and a gear ring. Both the first-stage and second-stage planetary gear pairs mesh with the gear ring. The first-stage planetary gear pair is connected to the input shaft of the reducer, the second-stage planetary gear pair is connected to the output shaft of the reducer, and the gear ring is rotatably connected to the motor shaft.

[0014] Furthermore, the coreless axial flux motor includes a motor housing, a first rotor, a stator, and a second rotor. The motor housing is fixedly connected to the bracket. The first rotor, the stator, and the second rotor are all located inside the motor housing. The first rotor and the second rotor are respectively located on both sides of the stator. The stator is fixedly connected to the motor housing. The first rotor and the second rotor are rotatably connected to the motor housing. The motor shaft is inserted into the motor housing and rotatably connected to the motor housing. The first rotor and the second rotor are fixedly sleeved outside the motor shaft.

[0015] Furthermore, a reducer receiving hole is provided at one end of the motor shaft; a reducer mating hole is provided at the other end of the motor shaft, the reducer receiving hole is connected to the reducer mating hole, the reducer receiving hole and the reducer mating hole form a stepped hole, the diameter of the reducer receiving hole is larger than the diameter of the reducer mating hole; the planetary gear reducer is located in the reducer receiving hole, and the reducer input shaft of the planetary gear reducer is inserted and matched with the reducer mating hole.

[0016] Furthermore, it also includes a wheel-end ECU fixedly mounted on the bracket, the wheel-end ECU being electrically connected to the eddy current motor position sensor.

[0017] To address the aforementioned technical problems, the present invention also provides an electromechanical wire-controlled braking system, the specific technical content of which is as follows: An electromechanical brake system includes the aforementioned electromechanical brake actuator.

[0018] To address the aforementioned technical problems, the present invention also provides a vehicle, the specific technical content of which is as follows: A vehicle that uses the aforementioned electromechanical brake-by-wire actuator for braking.

[0019] To address the aforementioned technical problems, this invention also provides a method for estimating the clamping force of an electromechanical wire-controlled brake actuator, the specific technical content of which is as follows: A method for estimating the clamping force of an electromechanical linear brake actuator includes the following steps: S1. Collect the angular displacement and current of the coreless axial flux motor; S2. Estimate the first clamping force of the brake based on the dynamic stiffness characteristics and the angular displacement of the motor; S3. Based on the torque balance principle, estimate the second clamping force of the brake according to the angular displacement of the motor and the motor current; S4. The maximum likelihood estimation method is used to determine the clamping force of the electromechanical linear brake actuator as the one with the highest probability between the first clamping force estimate and the second clamping force estimate. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of an electromechanical linear brake according to an embodiment of the present invention; Figure 2 This is a cross-sectional view of the inverse planetary roller screw pair in an embodiment of the present invention; Figure 3 This is a side view of the inverse planetary roller screw pair in an embodiment of the present invention; Figure 4 This is a cross-sectional view of the planetary gear reducer in an embodiment of the present invention; Figure 5 This is a side view of the planetary gear reducer in an embodiment of the present invention; Figure 6 This is a cross-sectional view of a hollow shaft coreless axial flux motor according to an embodiment of the present invention; Figure 7 This is a side view of the first rotor in an embodiment of the present invention; Figure 8 This is a cross-sectional view of the eddy current type motor position sensor in an embodiment of the present invention; Figure 9 This is a front view of the eddy current type motor position sensor in an embodiment of the present invention; Figure 10 This is a front view of the signal disk in an embodiment of the present invention; Figure 11 This is a stiffness characteristic curve diagram in an embodiment of the present invention.

[0021] The attached diagram lists the components represented by each number as follows: 1. Brake block; 2. Bracket; 3. Clamp body; 4. Reverse planetary roller screw pair; 5. Planetary gear reducer; 6. Coreless axial flux motor; 7. Eddy current motor position sensor; 8. Thrust bearing; 9. Wheel end ECU; 10. Lead screw; 11. Planetary roller; 12. Lead screw nut; 13. First-stage planetary gear pair; 1301. Reducer input shaft; 14. Second-stage planetary gear pair; 1401. Reducer output shaft; 15. Gear ring; 16. Motor shaft; 1601. Reducer receiving hole; 1602. Reducer mating hole; 17. Motor three-phase power interface; 18. First rotor; 1801. Rotor magnet; 19. Stator; 20. Second rotor; 21. Motor housing; 22. Induction coil; 23. Signal disk. Detailed Implementation

[0022] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0023] like Figure 1 As shown, this embodiment provides an electromechanical wire-controlled brake actuator, including a bracket 2. The bracket 2 is provided with a brake block 1, a clamp body 3, a reverse planetary roller screw pair 4, a planetary gear reducer 5, a coreless axial flux motor 6, and a wheel-end ECU 9. An eddy current type motor position sensor 7 is fixedly mounted on the coreless axial flux motor 6. The wheel-end ECU 9 is fixedly connected to the bracket 2 and electrically connected to the eddy current type motor position sensor 7.

[0024] Brake pad 1 consists of a steel plate, an adhesive heat insulation layer, and a friction block. It generates braking force through friction with the vehicle's brake disc. Brake bracket 2 is used to fix and support the caliper, ensuring stability and safety during braking. Specifically, it fixes and supports the caliper, enhancing braking performance and improving driving safety. Caliper body 3 has a U-shaped structure, made of cast steel, and fixes the brake pad, maintaining a proper clearance between the brake pad and the brake disc.

[0025] The motor shaft 16 of the coreless axial flux motor 6 is a hollow shaft. The planetary gear reducer 5 is located inside the motor shaft 16. The motor shaft 16 is connected to the reducer input shaft 1301 of the planetary gear reducer 5. The reducer output shaft 1401 of the planetary gear reducer 5 is connected to the lead screw 10 of the reverse planetary roller screw pair 4. The lead screw nut 12 of the reverse planetary roller screw pair 4 is connected to the brake block 1. An arc-shaped stop is provided at the right end of the motor shaft 16. The thrust groove, an arc-shaped thrust groove, is equipped with multiple thrust balls or thrust rollers. The thrust outer ring matches the multiple thrust balls or thrust rollers to form a thrust bearing 8 consisting of the motor shaft 16, multiple thrust balls or thrust rollers, and the thrust outer ring. The bearing cover restricts the position of the thrust outer ring of the thrust bearing 8 to prevent it from falling off. The bearing cover is fixedly connected to the motor housing 21 of the coreless axial flux motor 6 by screws or bolts. The motor housing 21 is fixedly connected to the bracket 2 by screws.

[0026] The coreless axial flux motor 6, in conjunction with the planetary gear reducer 5, drives the lead screw 10 of the inverse planetary roller screw pair 4 to rotate, thereby driving the lead screw nut 12 of the inverse planetary roller screw pair 4 to reciprocate on the bracket 2. This causes the lead screw nut 12 to drive the brake block 1 to reciprocate on the bracket 2, allowing the brake block 1 to move closer to or further away from the clamp body 3, ultimately achieving the clamping or releasing operation of the vehicle's brake disc. The eddy current type motor position sensor 7 is used to detect the rotation angle of the coreless axial flux motor 6.

[0027] The embodiments of the present invention employ a coreless hollow shaft axial flux motor, which has high magnetic flux density, no iron loss, line loss and heat generation, and an efficiency of over 95%. When outputting the same torque, the stator and rotor of the motor are smaller in size, the moment of inertia is smaller, the response is faster and the lag is smaller. It also has high integration and requires less installation space.

[0028] Employing an eddy current motor position sensor, the signal exhibits strong resistance to stray magnetic field interference; it is also resistant to shock and vibration; resistant to high temperatures with minimal temperature drift and higher accuracy; it can achieve angular acceleration acquisition and control; a built-in temperature sensor allows for temperature compensation of the motor position; and it features both analog and digital signal interfaces, ensuring a high level of safety.

[0029] The reverse planetary roller screw has a larger contact surface and more stable force distribution, which will not cause stress concentration. It is especially advantageous for the intermittent impact load of EMB. Its average life is 11 times that of ball screws of the same specification, so that the screw life matches the life of the EMB system.

[0030] The lead screw nut is integrated with the piston of the traditional brake actuator, that is, the lead screw nut replaces the piston of the traditional brake actuator, and the lead screw nut directly pushes the brake block 1 to brake the vehicle; the planetary gear reducer 5 is placed in the hollow shaft of the motor, so that the planetary gear reducer 5 and the motor are integrated into a single component and mounted on the bracket 2, eliminating the centering error of separate installation; the connecting structure is eliminated, reducing the failure points.

[0031] like Figures 2 to 3 As shown, one end of the lead screw nut 12 has a lead screw mating hole, which is rotatably connected to one end of the lead screw 10 via planetary rollers 11. The lead screw mating hole is a countersunk hole. The other end of the lead screw nut 12 is fixedly connected to the brake block 1. A hole or groove is provided on the bracket 2 to accommodate the lead screw nut 12, allowing the lead screw nut 12 to reciprocate within the hole or groove, but not to rotate within it. Specifically, both the lead screw nut 12 and the hole or groove accommodating it can be square holes or square grooves; alternatively, both the lead screw nut 12 and the hole or groove accommodating it can be polygonal holes or polygonal grooves. This allows the lead screw nut 12 to act as a piston pushing the brake block 1. The reverse planetary roller screw is also a dedicated transmission device developed from the perspective of EMB system requirements, converting rotary motion into translational motion. It simultaneously possesses both threaded drive and rolling helical drive. The rotation of the lead screw is converted into the translational motion of the lead nut through the planetary motion of the rollers. There is no axial displacement between the roller and the lead screw, or between the roller and the lead nut. The roller rolls and slides between the lead screw and the lead nut to achieve the transmission of motion and force.

[0032] like Figure 4 and Figure 5 The planetary gear reducer 5 is a two-stage planetary gear reducer. The two-stage planetary gear reducer includes a first-stage planetary gear pair 13, a second-stage planetary gear pair 14, and a gear ring 15. Both the first-stage planetary gear pair 13 and the second-stage planetary gear pair 14 mesh with the gear ring 15. The first-stage planetary gear pair 13 is connected to the reducer input shaft 1301, the second-stage planetary gear pair 14 is connected to the reducer output shaft 1401, and the gear ring 15 is rotatably connected to the motor shaft 16. The two-stage planetary gear reducer is used to reduce the speed and torque output from the hollow shaft coreless axial flux motor 6. The two-stage planetary gear pairs are in series; the reduction ratio of the first-stage planetary gear pair 13 is 6.60, the reduction ratio of the second-stage planetary gear pair 14 is 4.53, and the total reduction ratio of the two-stage planetary gear reducer is 29.92.

[0033] like Figure 6 and Figure 7As shown, the coreless axial flux motor 6 includes a motor housing 21, a first rotor 18, a stator 19, and a second rotor 20. The motor housing 21 is fixedly connected to the bracket 2. The first rotor 18, the stator 19, and the second rotor 20 are all located inside the motor housing 21. The first rotor 18 and the second rotor 20 are respectively located on both sides of the stator 19. The stator 19 is fixedly connected to the motor housing 21, and the first rotor 18 and the second rotor 20 are rotatably connected to the motor housing 21. The motor shaft 16 is inserted into the motor housing 21 and rotatably connected to it. The first rotor 18 and the second rotor 20 are fixedly sleeved on the outside of the motor shaft 16. A three-phase power interface 17 is also provided on the motor housing 21 for connecting the motor power supply. The first rotor 18, stator 19, and second rotor 20 are all ring-shaped disc structures. The stator 19 is made of copper. By engraving multiple coils in a ring array on both sides of the stator 19, electromagnetic force is applied to the rotor magnets 1801 on the first rotor 18 and the second rotor 20 to drive the first rotor 18 and the second rotor 20 to rotate, thus realizing the motor function. The first rotor 18 and the second rotor 20 are both provided with rotor magnets 1801, which are evenly distributed in a ring array on the first rotor 18 or the second rotor 20.

[0034] The coreless axial flux motor is a novel axial magnet motor designed and developed to meet the requirements of EMB actuator systems. It features a shared laser-lithographic stator and two axially opposed rotors with a double air gap design. The magnetic field direction is parallel to the motor shaft, and the axial magnetic field is tested by current to drive the motor rotation. With no iron losses and low heat generation, the coreless motor's high efficiency contributes to the high efficiency of the EMB system, and the EMB system experiences less brake fade due to high and low temperatures and lifespan. The coreless axial flux motor also boasts high magnetic flux density, providing higher output torque (i.e., braking clamping force) and safer braking. The motor body has a high degree of integration, a compact shape, and increased vehicle installation rate.

[0035] One end of the motor shaft 16 has a reducer receiving hole 1601; the other end of the motor shaft 16 has a reducer mating hole 1602, which connects to the reducer receiving hole 1601. The reducer receiving hole 1601 and the reducer mating hole 1602 form a stepped hole, and the diameter of the reducer receiving hole 1601 is larger than the diameter of the reducer mating hole 1602. The planetary gear reducer 5 is located inside the reducer receiving hole 1601, and the reducer input shaft 1301 of the planetary gear reducer 5 is inserted and matched with the reducer mating hole 1602. By placing the planetary gear reducer 5 inside the reducer receiving hole 1601, the axial dimension can be reduced, making the entire brake actuator structure more compact.

[0036] like Figure 8 , Figure 9 as well as Figure 10 As shown, the eddy current motor position sensor includes a circuit board, a signal disk 23, and a chip. The circuit board has multiple layers of induction coils 22; each layer of induction coils 22 includes one transmitting coil and two receiving coils with a 90° phase difference. The transmitting coil, controlled by the chip, generates a high-frequency oscillating magnetic field of 2–5 MHz; the 90° orthogonal sine and cosine receiving coils generate a high-frequency oscillating induced electromotive force due to electromagnetic induction. After demodulating the received high-frequency signal, the chip obtains the sine and cosine envelope analog signals (with the high-frequency carrier signal removed), which are then input to the microcontroller (MCU). The metal signal disk 23, by inducing eddy currents, weakens the excitation magnetic field of the transmitting coil, and the induced electromotive force of the receiving coil is correspondingly weakened. As the signal disk 23 rotates, the induced electromotive force of the receiving coil changes with the area covered by the sine and cosine coils. Advantages: ① High accuracy of differential sine and cosine signal analog output, angle error ≤ ±1°; strong anti-common-mode noise capability. ② Output real-time delay ≤ 4μs. ③ Input and output decoupling enables good EMC performance while maintaining a stable output amplitude. ④ Wide operating voltage range (-18V to +18V), with overvoltage and reverse polarity protection. ⑤ Strong anti-interference capability against DC and AC stray magnetic fields. A signal disk 23 is fixedly mounted on the motor shaft 16. Multiple signal teeth are intermittently arranged on the outer circumference of the signal disk 23, and the multiple signal teeth and the signal disk 23 are integrated into one structure. The induction coil 22 of the eddy current type motor position sensor 7 is directly opposite the signal teeth on the outer circumference of the signal disk 23.

[0037] The eddy current type motor position sensor 7 is used to measure the angle (i.e., position) of the motor rotor in real time. The wheel-side controller MCU controls the motor rotor rotation angle to achieve precise control of the clamping force of the EMB actuator. It adopts the eddy current principle, and the chip model is TAS4240-AAAA. The wheel-side controller MCU needs to obtain the current rotation angle of the motor to determine its position. The motor position sensor collects the motor angle and converts it into a sine and cosine voltage signal, which is transmitted to the vehicle ECU through an interface circuit. The interface circuit filters the incoming signal and provides a certain diagnostic mechanism for the signal lines.

[0038] The TLE5501-E002 chip is based on the tunnel magnetoresistive principle and can measure 360° angles. Two independent Wheatstone bridges generate four sine and cosine signals for differential calculation, and then the arctangent is used to obtain the angle, thereby obtaining the position of the motor.

[0039] In some other embodiments, an electromechanical wire braking system is also provided, including the above-described electromechanical wire braking actuator.

[0040] In other embodiments, a vehicle is also provided that uses the aforementioned electromechanical brake-by-wire actuator for braking.

[0041] In some other embodiments, a method for estimating the clamping force of an electromechanical wire brake actuator is also provided, comprising the following steps: S1. Collect the angular displacement and current of the coreless axial flux motor 6. S2. Estimate the first clamping force of the brake based on the dynamic stiffness characteristics and the angular displacement of the motor; like Figure 11 As shown, the estimated value of the first clamping force of the brake is estimated based on the dynamic stiffness characteristics and the angular displacement of the motor. The specific scheme is as follows: The relationship between clamping force and motor angular displacement is the dynamic stiffness characteristic.

[0042] The contact point is identified by setting a threshold difference between the motor current and the angular displacement, thus determining the initial position and avoiding the influence of brake pad wear on the estimation results.

[0043] Based on a simplified braking model, the average dynamic stiffness characteristics are corrected by a scaling factor.

[0044] Establish dynamic stiffness characteristic estimation models under different thermal conditions to correct for the interference of factors such as temperature and friction on dynamic stiffness characteristics.

[0045] Due to the hysteresis effect of clamping force caused by friction and the elastic properties of the brake disc, a clamping force hysteresis estimation model is established to ensure the accuracy of clamping force estimation when the direction of motion changes transiently.

[0046] The dynamic stiffness model is modified as the EMB caliper's lifespan progresses to obtain the proportional relationship equation between the motor angular displacement and the estimated value of the first clamping force, thereby using the proportional relationship equation to calculate the estimated value of the first clamping force.

[0047] S3. Based on the torque balance principle, estimate the second clamping force of the brake according to the angular displacement of the motor and the motor current; The formula for calculating the estimated value of the second clamping force is as follows: ; in, This indicates the estimated value of the second clamping force. This refers to the electromagnetic force of the motor. Indicates the lever arm. , These represent the motor's current and angular displacement, respectively. , Let represent the motor torque constant and the equivalent moment of inertia at the motor output, respectively. Represents frictional torque. This represents the angular acceleration of the motor. t Indicates time.

[0048] S4. The maximum likelihood estimation method is used to determine the clamping force of the electromechanical linear brake actuator as the value with the highest probability between the first and second clamping force estimates. Combined with a genetic algorithm and Kalman filtering, an optimal estimate of the clamping force is provided, improving the accuracy and robustness of the clamping force estimation method.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the concept and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An electromechanical linear braking actuator, characterized in that, Includes a bracket (2), on which are provided a brake block (1), a clamp (3), a reverse planetary roller screw pair (4), a planetary gear reducer (5) and a coreless axial flux motor (6), on which are fixed an eddy current type motor position sensor (7). The motor shaft (16) of the coreless axial flux motor (6) is a hollow shaft. The planetary gear reducer (5) is located inside the motor shaft (16). The motor shaft (16) is connected to the reducer input shaft (1301) of the planetary gear reducer (5). The reducer output shaft (1401) of the planetary gear reducer (5) is connected to the lead screw (10) of the reverse planetary roller screw pair (4). The lead screw nut (12) of the reverse planetary roller screw pair (4) is connected to the brake block (1). The coreless axial flux motor (6) works in conjunction with the planetary gear reducer (5) to drive the lead screw (10) of the inverted planetary roller screw pair (4) to rotate, thereby driving the lead screw nut (12) of the inverted planetary roller screw pair (4) to reciprocate on the bracket (2), thereby driving the lead screw nut (12) to drive the brake block (1) to reciprocate on the bracket (2); the eddy current type motor position sensor (7) is used to detect the rotation angle of the coreless axial flux motor (6).

2. The electromechanical linear brake actuator according to claim 1, characterized in that, One end of the lead screw nut (12) has a lead screw mating hole, and the lead screw mating hole is rotatably connected to one end of the lead screw (10) through a planetary roller (11). The lead screw mating hole is a countersunk hole. The other end of the lead screw nut (12) is fixedly connected to the brake block (1).

3. The electromechanical linear brake actuator according to claim 2, characterized in that, The planetary gear reducer (5) is a two-stage planetary gear reducer.

4. The electromechanical linear brake actuator according to claim 3, characterized in that, The two-stage planetary gear reducer includes a first-stage planetary gear pair (13), a second-stage planetary gear pair (14), and a gear ring (15). The first-stage planetary gear pair (13) and the second-stage planetary gear pair (14) are both meshed with the gear ring (15). The first-stage planetary gear pair (13) is connected to the input shaft (1301) of the reducer, the second-stage planetary gear pair (14) is connected to the output shaft (1401) of the reducer, and the gear ring (15) is rotatably connected to the motor shaft (16).

5. The electromechanical linear braking actuator according to claim 1, characterized in that, The coreless axial flux motor (6) includes a motor housing (21), a first rotor (18), a stator (19), and a second rotor (20). The motor housing (21) is fixedly connected to the bracket (2). The first rotor (18), the stator (19), and the second rotor (20) are all located inside the motor housing (21). The first rotor (18) and the second rotor (20) are located on both sides of the stator (19). The stator (19) is fixedly connected to the motor housing (21). The first rotor (18) and the second rotor (20) are rotatably connected to the motor housing (21). The motor shaft (16) is inserted into the motor housing (21). The motor shaft (16) is rotatably connected to the motor housing (21). The first rotor (18) and the second rotor (20) are fixedly sleeved outside the motor shaft (16).

6. The electromechanical linear brake actuator according to claim 5, characterized in that, One end of the motor shaft (16) is provided with a reducer receiving hole (1601); the other end of the motor shaft (16) is provided with a reducer mating hole (1602), the reducer receiving hole (1601) and the reducer mating hole (1602) are connected, the reducer receiving hole (1601) and the reducer mating hole (1602) form a stepped hole, the diameter of the reducer receiving hole (1601) is larger than the diameter of the reducer mating hole (1602); the planetary gear reducer (5) is located in the reducer receiving hole (1601), and the reducer input shaft (1301) of the planetary gear reducer (5) is inserted and matched with the reducer mating hole (1602).

7. The electromechanical linear braking actuator according to claim 1, characterized in that, It also includes a wheel end ECU (9) fixed on the bracket (2), and the wheel end ECU (9) is electrically connected to the eddy current type motor position sensor (7).

8. An electromechanical linear braking system, characterized in that, Including the electromechanical linear braking actuator as described in any one of claims 1 to 7.

9. A vehicle, characterized in that, Braking is performed using an electromechanical linear brake actuator as described in any one of claims 1 to 7.

10. A method for estimating the clamping force of an electromechanical linear brake actuator as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Collect the angular displacement and current of the coreless axial flux motor (6); S2. Estimate the first clamping force of the brake based on the dynamic stiffness characteristics and the angular displacement of the motor; S3. Based on the torque balance principle, estimate the second clamping force of the brake according to the angular displacement of the motor and the motor current; S4. The maximum likelihood estimation method is used to determine the clamping force of the electromechanical linear brake actuator as the one with the highest probability between the first clamping force estimate and the second clamping force estimate.

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