Wired brake module, wired brake system, and control method thereof

Abstract

To provide a wired brake module and a method capable of coping with an extreme brake condition.SOLUTION: In a control method, S2 when it is estimated that current front stroke of a main piston cannot satisfy a brake request, steps are performed, the steps including: S31 performing current front stroke until stroke of the main piston reaches a first threshold, and disconnecting communication between a master brake cylinder and each of sub-brake cylinders; S32 drawing the main piston until the master brake cylinder communicates with a storage part, and allowing brake fluid from the storage part to be replenished in the master brake cylinder; S33 causing the main piston to advance again, reestablishing communication between the master brake cylinder and the sub-brake cylinder, and further increasing a brake fluid pressure of each of the sub-brake cylinder; and S34 returning to step S2.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present disclosure relates to the field of vehicle brakes, and more specifically, to a wired brake module, a wired brake system, and a control method for a wired brake system.

Background Art

[0002] Wired brake systems, especially electronic hydraulic brake systems (EHBs), are a new type of brake system developed from conventional hydraulic brake systems. These are more convenient for integration with systems such as electric vehicles, intelligent driving, or autonomous driving. The main differences between a wired brake system and a conventional hydraulic brake system are the use of an electronic brake pedal instead of a conventional brake pedal, and the replacement of the mechanical connection between the brake pedal and the brake module with an electronic connection or a communication connection. This achieves the separation of the electronic brake pedal from the master brake cylinder, enabling full electronic control of the braking operation.

[0003] On the one hand, the volume of the master brake cylinder of a vehicle and the stroke of the main piston in the master brake cylinder need to be designed based on extreme braking conditions. For example, when a vehicle is on a long downhill gradient, the driver tends to repeatedly depress the electronic brake pedal, which can lead to an increase in the temperature of the brake caliper, a decrease in the friction coefficient, and deformation under pressure. In such cases, a larger amount of brake fluid is required compared to normal road conditions. Such conditions are rare and may not even need to be considered for vehicles used in urban environments, but the existing design of the master brake cylinder must have the ability to handle these conditions.

Summary of the Invention

Problems to be Solved by the Invention

[0004] This application aims to solve or at least mitigate the problems existing in the prior art.

Means for Solving the Problems

[0005] According to one aspect of the present disclosure, a control method for a wired braking system is provided. This control method includes: S1. When receiving a braking request from an electronic brake pedal, driving a main piston in a master brake cylinder forward to compress the brake fluid in the master brake cylinder into sub-brake cylinders of brake calipers of each wheel, thereby establishing a brake fluid pressure. This method further includes: S2. Estimating whether the current forward stroke of the main piston can satisfy the braking request. If the result is affirmative, executing the current forward stroke until the braking request is satisfied; If the above result is negative, S31. Executing the current forward stroke until the stroke of the main piston reaches a first threshold value, and disconnecting the communication between each of the master brake cylinder and the sub-brake cylinders; S32. Retracting the main piston until the master brake cylinder communicates with a storage portion, enabling the brake fluid from the storage portion to replenish the master brake cylinder; S33. Advancing the main piston forward again, re-establishing the communication between each of the master brake cylinder and the sub-brake cylinders, and further increasing the brake fluid pressure in each of the sub-brake cylinders; S34. Returning to step S2; and performing the above steps. This method further includes the above steps.

[0006] According to another aspect of the present disclosure, a wired braking system is provided that executes the method according to any embodiment of the present disclosure.

[0007] According to another aspect of the present disclosure, a wired brake module is provided. This module includes: a drive motor, a first electronic control unit communicably connected to the drive motor, a main push rod drivingly connected to the drive motor, a master brake cylinder having a main piston and an auxiliary piston, the main piston and the auxiliary piston that divide the master brake cylinder into a first chamber and a second chamber, a first return spring between the main piston and the auxiliary piston, a second return spring between the auxiliary piston and an end wall of the master brake cylinder, and comprising the main piston, when in an initial position, contacts the main push rod, the first chamber and the second chamber each communicate with a reservoir, when the first electronic control unit receives a brake request from an electronic brake pedal, controls the drive motor to drive the main piston in the master brake cylinder forward to compress the brake fluid in the master brake cylinder, estimates whether the current forward stroke of the main piston can satisfy the brake request, and if the result is affirmative, executes the current forward stroke until the brake request is satisfied, if the result is negative, the following steps: execute the current forward stroke until the stroke of the main piston exceeds a predetermined threshold, then transmit a first signal to an electronic stability module of the vehicle body to notify to disconnect the master brake cylinder from each of the sub-brake cylinders, retract the main piston until the master brake cylinder communicates with the reservoir, enabling the brake fluid from the reservoir to refill the master brake cylinder, advance the main piston again and transmit a second signal to the electronic stability module of the vehicle body to notify to control the reconnection of the master brake cylinder with each of the sub-brake cylinders, is configured to execute.

[0008] The apparatus and method according to the present disclosure can handle extreme braking conditions via control logic and make the wired brake module more compact.

Brief Description of the Drawings

[0009] Referring to the accompanying drawings, the present disclosure will be more easily understood. Those skilled in the art can easily understand that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this application. Additionally, like numbers in the figures are used to represent similar components.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0010] First, referring to FIGS. 1 to 7, a wired brake system and its control method according to an embodiment of the present disclosure will be introduced. The wired brake system can include a wired brake module 2 and an electronic stability module 3 of a vehicle body. In addition to the wired brake system, the vehicle brake assembly further includes an electronic brake pedal 1 for the four wheels of the vehicle and brake calipers 41, 42, 43, 44. The electronic brake pedal 1 can be equipped with or without the feeling of the pedal or the movement of the pedal, and the control signal of the electronic brake pedal 1 can include, for example, the movement, angle, or pressure of the brake pedal. Each brake caliper employs a hydraulic brake caliper and each has a sub-hydraulic cylinder 41, 42, 43, 44. The wired brake module 2 may include a drive motor 22, a first electronic control unit 21 communicably connected to the drive motor 22, and a main push rod 23 drivingly connected to the drive motor 22. For example, the output shaft 221 of the drive motor 22 and the gear 231 form a worm gear mechanism, and the gear 231 and the main push rod 23 form a screw nut mechanism, thereby enabling the drive motor 22 to move the main push rod 23 forward or retract it. A master brake cylinder 28, and the master brake cylinder 28 in which a main piston 24 and an auxiliary piston 25 are disposed divides the first chamber 271 and the second chamber 272. A first return spring 291 and a second return spring 292 (only shown in FIG. 1) are disposed between the main piston 24 and the auxiliary piston 25, and between the auxiliary piston 25 and the end wall of the master brake cylinder 28. When the main piston 24 is in the initial position (the drive motor 22 is in the initial position), the main piston 24 contacts the main push rod 23, and the first chamber 271 and the second chamber 272 communicate with a storage portion 26 through independent pipelines 261, 262 communicating with the storage portion 26, respectively.The seal is arranged near the ports where the pipelines 261 and 262 enter the brake cylinder 28. As a result, it will be understood that when the main piston 24 and the auxiliary piston 25 move leftward beyond their respective ports, the first chamber 271 and the second chamber 272 are sealed from the reservoir 26.

[0011] The electronic stability module 3 of the vehicle body comprises a first passage 34 and a second passage 32 which fluidly connect the first chamber 271 and the second chamber 272 to two sub-brake cylinders of the brake calipers of two wheels respectively. More specifically, the first passage 34 connects the first chamber 271 and branches into a first branch 341 and a second branch 342, which are connected to a first sub-brake cylinder 43 and a second sub-brake cylinder 44 of a first brake circuit 46, which may be the brake cylinders of the brake calipers of the left front wheel and the right rear wheel respectively. Similarly, the second passage 32 connects the second chamber 272 and branches into a third branch 321 and a fourth branch 322, which are connected to a third sub-brake cylinder 41 and a fourth sub-brake cylinder 42 of a second brake circuit 45, which may be the brake cylinders of the brake calipers of the left rear wheel and the right front wheel respectively. The first main valve 35 and the second main valve 33 are arranged on the first passage 34 and the second passage 32 respectively, and the second electronic control unit 31 is communicably connected to the first main valve 35 and the second main valve 33. The pressure sensor 36 is connected to the first main valve 35 on the master brake cylinder side of the first passage 34 (arranged as shown in the illustrated embodiment), or the second main valve 33 on the master brake cylinder side of the second passage 32, thereby monitoring the brake fluid pressure on the master brake cylinder side of the first main valve 35 of the first passage 34, or the brake fluid pressure on the master brake cylinder side of the second main valve 33 of the second passage 32. In addition to the above-described components, the electronic stability module 3 of the vehicle body further comprises other components for achieving the vehicle body stability function, which are not detailed here.

[0012] Furthermore, in the wired brake system, the first electronic control unit 21 and the second electronic control unit 31 are communicatively connected. The electronic brake pedal 1 is communicatively connected to both the first electronic control unit 21 and the second electronic control unit 31. Furthermore, although not shown, the electronic brake pedal 1, the first electronic control unit 21, and the second electronic control unit 31 can each be electrically connected to a first power source and a second power source, whereby power can be supplied to all three power sources, the first power source may be the main power source, and the second power source may be a backup power source. From the above description, in the wired brake system according to the embodiments of the present application, it is clear that the electronic brake pedal 1 is communicatively connected only to the wired brake module 2, and the main push rod 23 completely depends on the drive motor 22 for operation. In contrast, in a conventional mechanical pedal, the brake pedal 1 is mechanically connected to the main push rod 23 such that depressing the brake pedal 1 directly pushes the main push rod 23, and the motor provides only auxiliary assistance.

[0013] In the wired brake module 2, in step S1, when a brake request is received from the electronic brake pedal 1, the first electronic control unit 21 controls the drive motor 22 to rotate forward, and advances the main push rod 23 through the transmission mechanism. The main push rod 23 further advances the main piston 24 in the master brake cylinder 28, compressing the brake fluid in the master brake cylinder. For example, the brake fluid in the first chamber 271 and the second chamber 272 enters the sub-brake cylinders 41, 42, 43, 44 of the brake calipers of each wheel, thereby establishing a brake fluid pressure. When a brake release request is received from the electronic brake pedal 1, the first electronic control unit 21 controls the drive motor 22 to reverse and contract the main push rod 23 through the transmission mechanism. At that time, the main piston 24 and the auxiliary piston 25 return to their initial positions by the elastic force of the first and second return springs 291, 292.

[0014] Next, referring to FIG. 7, a control method for a wired braking system will be introduced. In the wired braking system shown in FIGS. 1 to 6, the main entities that execute this method are both the first electronic control unit 21 of the wired brake module 2 and the second electronic control unit 31 of the electronic stability module 3 of the vehicle body. Specifically, the method is mainly executed by the first electronic control unit 21, but the steps involving the disconnection and communication of the passage between the master brake cylinder and the sub-brake cylinder can be executed by the second electronic control module 31 based on a notification from the first electronic control unit 21. In an alternative embodiment, the method can also be executed by a single electronic control unit, control device, or processor. For example, the first electronic control unit 21 and the second electronic control unit 31 can be integrated together. Therefore, the execution entity of the control method of the present disclosure is not limited by a specific embodiment. The control method of the wired braking system includes: S1. When receiving a braking request from the electronic brake pedal 1, driving the main piston in the master brake cylinder forward to compress the brake fluid in the master brake cylinder into the sub-brake cylinder of the brake caliper of each wheel, thereby establishing a brake fluid pressure. Although a master brake cylinder having a main piston and an auxiliary piston is illustrated, it should be understood that the method of the present disclosure can be applied to master brake cylinders of various structures.

[0015] After step S1, step S2 is executed to estimate whether the current forward stroke of the main piston can meet the braking requirement. If the result is affirmative, the current forward stroke is executed until the braking requirement is met. If the result is negative, the following steps can be executed. In the master brake cylinder of the present disclosure, the main piston, the auxiliary piston, and the master brake cylinder are configured such that a single forward stroke of the main piston and the auxiliary piston meets only the braking needs under conventional operating conditions, rather than under extreme braking conditions such as long downhill conditions. For extreme braking conditions, the methods described below are used to address them. Therefore, compared with conventional products, the length of the master brake cylinder in the embodiments of the present disclosure may be shorter, and the single stroke of the main piston and the auxiliary piston may also be shorter, thereby achieving a more compact wired brake module. Nevertheless, a single forward stroke of the main piston and the auxiliary piston can meet most conventional operating conditions. Therefore, in most cases, the judgment result is affirmative, and the main piston advances to a predetermined position according to the conventional control method for executing the brake. For example, taking the state shown in FIG. 2 as an example, when the main piston 24 moves to the illustrated position, the pipeline having the high-pressure brake fluid is shown in bright color in the figure. The high-pressure brake fluid enters the sub-brake cylinders 41, 42, 43, 44 of the brake calipers of each wheel and can provide a braking force corresponding to the current braking requirement. Further, if the judgment result is negative, steps S31 to S34 are executed. In some embodiments, step S2 includes collecting one or more parameters during the forward stroke of the main piston and estimating whether the maximum stroke of the main piston can meet the braking requirement based on a comparison of the one or more collected parameters with historical parameters or preset parameters.One or more parameters are selected from, for example, vehicle speed, vehicle deceleration, stroke of the main push rod 23, rotor position of the drive motor 22, brake fluid pressure in the sub-brake cylinder, and / or brake torque.

[0016] Parameters such as the volume of the master brake cylinder of the vehicle, the volume of the sub-brake cylinder, and the length of the pipeline between the master brake cylinder and the sub-brake cylinder are known and determined parameters on the vehicle and should be understood as such. Other parameters such as the friction coefficient of the friction pads of the brake caliper and the thickness of the friction pads can vary under extreme conditions. Based on the aforementioned known and determined parameters, there is a corresponding relationship between the position of the main piston 24 and the braking torque applied by the brake caliper under general conditions. These corresponding parameters can be preset in the first electronic control unit 21 as preset parameters. On the one hand, the first electronic control unit 21 can also periodically collect the corresponding relationship between the position of the main piston 24 and the braking torque applied by the brake caliper under conventional conditions and store it as historical data (which can be updated periodically). On the other hand, there may be a corresponding relationship between the position of the main piston 24 and the stroke or pressure of the electronic brake pedal 1. Therefore, in the specific determination method of step S2, when the stroke or pressure of the electronic brake pedal 1 is small, for example, when the corresponding position of the main piston is less than a specific ratio R (for example, 80%, 70%, and 60%) of the maximum forward stroke of the main piston, since there is a large margin in the forward stroke of the main piston itself, it can be directly determined that the current forward stroke of the main piston can meet the braking requirement. Conversely, when the stroke or pressure of the electronic brake pedal 1 is large, for example, when the corresponding position of the main piston is equal to or greater than the ratio R (for example, 80%, 70%, 60%) of the maximum forward stroke of the main piston, when the main piston 24 advances to the position corresponding to the ratio R, one or more of the above parameters such as the deceleration can be collected, and the collected deceleration is compared with the preset deceleration or historical value of the system when the main piston is in that position under conventional conditions. Based on this comparison, it is estimated whether the current braking requirement can be met before the main piston continues its forward stroke to the maximum forward stroke.More specifically, as an embodiment, when the ratio R is 80% and the depth or force of the driver's depression of the brake pedal corresponds to 90% of the maximum forward stroke of the main piston, when the main piston moves to 80% of the maximum forward stroke, the current actual deceleration is detected and compared with a preset or historical value of the deceleration. If the two are equal, the main piston is determined to be able to satisfy the current brake demand when moving to 90%. If the actual deceleration is only 70% of the set value or historical value, even if the current piston forward stroke reaches 100%, it can be presumed that the brake demand cannot be satisfied, and steps S31 to S34 are executed. In some embodiments, step S2 includes collecting one or more parameters when the stroke of the main piston reaches a second threshold that is 80% to 90% of the maximum stroke of the main piston. It will be understood that the foregoing determination method is merely illustrative. Those skilled in the art are proficient in various methods for controlling the main piston stroke based on the brake demand, and based on the feedback from the parameters collected at a fixed position or the real-time feedback of the collected parameters, it is possible to estimate whether the brake demand can be satisfied through various mathematical models. Therefore, the implementation of step S2 is not limited to the above-described embodiments.

[0017] If it is determined that the current maximum forward stroke of the main piston cannot satisfy the brake demand, the following steps can be executed. That is, S31. Until the stroke of the main piston reaches the first threshold, execute the current forward stroke and disconnect the communication between each of the master brake cylinder and the sub-brake cylinder; S32. Retract the main piston until the master brake cylinder communicates with the storage portion, enabling the brake fluid from the storage portion to replenish the master brake cylinder; S33. Advance the main piston again to re - establish communication between each of the master brake cylinder and the sub - brake cylinders, and further increase the brake fluid pressure in each of the sub - brake cylinders, and S34. Return to step S2, and can be executed.

[0018] In some embodiments, the first threshold is set to 80% to 100% of the maximum forward stroke of the main piston. For example, as shown in FIG. 3, the first threshold may be 100% of the maximum forward stroke of the main piston. At that time, the brake fluid in the first chamber and the second chamber is substantially transferred to the first passage 34, the second passage 32, and each sub - brake cylinder. At this point, the communication between the main brake cylinder and each sub - brake cylinder is cut off, which can be achieved by cutting off the ports of the main brake cylinder or each sub - brake cylinder or the pipeline between them. In the embodiments of the present disclosure, the first main valve 35 and the second main valve 33 are respectively arranged on the first passage 34 and the second passage 32, and step S31 includes closing the first main valve 35 and the second main valve 33. After the first main valve 35 and the second main valve 33 are closed, the brake fluid in the pipeline on the side surface of the sub - brake cylinder and in the sub - brake cylinder remains under high pressure, thereby maintaining the brake torque of each wheel. Even during the subsequent retraction of the main piston in S32, the pressure in each sub - brake cylinder is not affected. In some embodiments, step S31 further includes recording the first pressure P1 of the brake fluid in the first passage 34 or the second passage 32 before the main piston stroke reaches the first threshold and before closing the first main valve 35 and the second main valve 33. This step can be implemented by a pressure sensor 36 connected to the first passage 34.

[0019] After step S31 is completed, as shown in FIGS. 4 and 5, step S32 is executed. The main piston is retracted until the main brake cylinder communicates with the storage portion (the state shown in FIG. 5). As a result, the brake fluid in the storage portion is replenished into the main brake cylinder, for example, the first chamber 271 and the second chamber 272. This step can be achieved by reversing the drive motor 22 to return it to the initial position, returning the main push rod 23 to the initial position. At this point, the main piston 24 and the auxiliary piston 25 return to the initial position under the action of the return spring. As can be seen from the figure, in this step, the brake fluid on the side of the main brake cylinder of the first main valve 35 and the second main valve 33, as well as the brake fluid in the first chamber 271 and the second chamber 272, becomes a low-pressure state. In some embodiments, in order to avoid the generation of a large negative pressure, the first threshold can alternatively be set to 95% of the maximum forward stroke of the main piston or other appropriate values so that some of the brake fluid remains in the main brake cylinder. In the state shown in FIG. 5, the brake fluid in the storage portion 26 is replenished into the main brake cylinder, for example, into its first chamber 271 and the second chamber 272.

[0020] After step S32 is completed, as shown in FIG. 6, step S33 is executed. The main piston 24 advances again, and the main brake cylinder is reconnected to each sub-brake cylinder to further increase the brake fluid pressure in each sub-brake cylinder. In some embodiments, step S33 includes monitoring a second pressure P2 of the brake fluid on the side of the main brake cylinder of the first main valve 35 in the first passage or the second main valve 33 in the second passage during the re-advancement of the main piston 24. When the second pressure P2 is equal to or greater than the first pressure P1, the first main valve 35 and the second main valve 33 are opened to reconnect the main brake cylinder to each sub-brake cylinder. The second pressure P2 can also be detected by a pressure sensor 36 that communicates with the side of the main brake cylinder of the first main valve 35 on the first passage 34. This pressure comparison step prevents backflow of the brake fluid and the resulting reduction in braking force. After step S33, step S34 is executed, and step S34 returns to step S2 to determine whether the second forward stroke can meet the brake demand. Generally, in extreme cases, the main piston 24 may even need to execute two or three forward strokes, that is, one or two times, steps S31 to S34. Accordingly, the length of the main brake cylinder and the stroke of the main push rod can be reduced to 1 / 2 or even shorter than the length of existing products. Therefore, according to another aspect of the present disclosure, a wired brake system is provided that enables the execution of methods according to various embodiments and reduces the length of its main brake cylinder and / or the stroke with the main push rod to further 1 / 2 of existing products.

[0021] According to still another aspect, there is provided a wired brake module 2 including a drive motor 22, a first electronic control unit 21 communicably connected to the drive motor 22, a main push rod 23 drivably connected to the drive motor 22, and a main brake cylinder 28 in which a main piston 24 and an auxiliary piston 25 are disposed, the main brake cylinder being divided into a first chamber 271 and a second chamber 272. When the main piston is in the initial position, the main piston 24 contacts the main push rod 23, and the first chamber 271 and the second chamber 272 communicate with the storage portion 26 respectively. When the first electronic control unit 21 receives a brake request from the electronic brake pedal 1, it performs the following steps: controlling the drive motor to drive the main piston in the master brake cylinder forward to compress the brake fluid in the master brake cylinder; estimating whether the current forward stroke of the main piston can meet the brake request; if the result is affirmative, executing the current forward stroke until the brake request is satisfied; if the result is negative, performing the following steps: executing the current forward stroke until the stroke of the main piston exceeds a predetermined threshold; sending a first signal to the electronic stability module of the vehicle body to notify disconnecting the master brake cylinder from each of the sub-brake cylinders; retracting the main piston until the master brake cylinder communicates with the storage portion to enable the brake fluid from the storage portion to replenish the master brake cylinder; and advancing the main piston again.

[0022] The specific examples described above in this application are merely for more clearly explaining the principle of this application, and various components are clearly shown or described in order to make the principle of this disclosure easier to understand. Those skilled in the art can easily make various modifications or changes to this application within the scope of this application. Therefore, it should be understood that all these modifications or changes are included within the scope of patent protection of this application.

Claims

1. A method for controlling a wired braking system, comprising: S1. When a braking request is received from the electronic brake pedal (1), driving the main piston (24) in the master brake cylinder (28) forward to compress the brake fluid in the master brake cylinder (28) into the sub-brake cylinders (41, 42, 43, 44) of the brake calipers of each wheel, thereby establishing a brake fluid pressure. In the method, the method further comprises: S2. Estimating whether the current forward stroke of the main piston (24) can satisfy the braking request. If the result is affirmative, executing the current forward stroke until the braking request is satisfied; If the result is negative, S31. Executing the current forward stroke until the stroke of the main piston (24) reaches a first threshold value, and disconnecting the communication between the master brake cylinder (28) and each of the sub-brake cylinders (41, 42, 43, 44); S32. Retracting the main piston (24) until the master brake cylinder (28) communicates with the storage portion (26), enabling the brake fluid from the storage portion (26) to replenish the master brake cylinder (28); S33. Advancing the main piston (24) again, re-establishing the communication between the master brake cylinder (28) and each of the sub-brake cylinders (41, 42, 43, 44), and further increasing the brake fluid pressure in each of the sub-brake cylinders (41, 42, 43, 44); S34. Returning to step S2; and executing the above steps, characterized by the method.

2. The method according to claim 1, wherein the first threshold value is 80% to 100% of the maximum forward stroke of the main piston (24).

3. Step S2 includes: collecting one or more parameters during the forward stroke of the main piston (24); estimating whether the current maximum stroke of the main piston (24) can satisfy the braking request based on a comparison between the one or more collected parameters and historical parameters or preset parameters. and The one or more parameters are selected from vehicle speed, vehicle deceleration, main push rod stroke, drive motor rotor position, brake fluid pressure in the sub-brake cylinder, and / or brake torque. The method according to claim 1, characterized in that.

4. Step S2 includes collecting one or more parameters when the stroke of the main piston (24) reaches a second threshold. The method according to claim 3, characterized in that the second threshold is 80% to 90% of the maximum stroke.

5. The master brake cylinder (28) includes a first chamber (271) and a second chamber (272). The first chamber (271) is connected to the first sub-brake cylinder and the second sub-brake cylinder via a first passage (34). The second chamber (272) is connected to the third sub-brake cylinder and the fourth sub-brake cylinder via a second passage (32). A first main valve (35) and a second main valve (33) are respectively arranged on the first passage (34) and the second passage (32). Step S31 includes closing the first main valve (35) and the second main valve (33). The method according to claim 1, characterized in that.

6. The method according to claim 5, characterized in that step S31 further includes recording a first pressure P1 of the brake fluid in the first passage (34) or the second passage (32) before the stroke of the main piston (24) reaches the first threshold and before closing the first main valve (35) and the second main valve (33).

7. Step S33 is monitoring a second pressure P2 of the brake fluid on the side of the main brake cylinder of the first main valve (35) in the first passage (34) or the second main valve (33) in the second passage (32) during the forward movement of the main piston (24); opening the first main valve (35) and the second main valve (33) when the second pressure P2 is greater than or equal to the first pressure P1. The method according to claim 5, characterized by including.

8. The wired brake system is characterized by implementing the method according to any one of claims 1 to 7.

9. The wired brake system is A wired brake module (2), comprising: a drive motor (22); a first electronic control unit (21) communicably connected to the drive motor (22); a main push rod (23) drivingly connected to the drive motor (22); a master brake cylinder (28) including a main piston (24) and an auxiliary piston (25); the main piston (24) and the auxiliary piston (25) that divide the master brake cylinder (28) into a first chamber (271) and a second chamber (272); a first return spring (291) between the main piston (24) and the auxiliary piston (25); and a second return spring (292) between the auxiliary piston (25) and an end wall of the master brake cylinder (28), wherein when the main piston (24) is in the initial position, it contacts the main push rod (23), and the first chamber (271) and the second chamber (272) each communicate with a storage portion (26). An electronic stability module (3) of a vehicle body, comprising: a first passage (34) fluidly connecting the first chamber (271) to a first sub-brake cylinder and a second sub-brake cylinder; a second passage (32) fluidly connecting the second chamber (272) to a third sub-brake cylinder and a fourth sub-brake cylinder; a first main valve (35) and a second main valve (33) respectively disposed on the first passage (34) and the second passage (32); a second electronic control unit (31) communicably connected to the first main valve (35) and the second main valve (33); and a pressure sensor (36) for monitoring a brake fluid pressure on a side surface of a main brake cylinder of the first main valve (35) of the first passage (34) or the second main valve (33) of the second passage (32). Comprising The wired brake system according to claim 8, wherein the first electronic control unit (21) and the second electronic control unit (31) are communicably connected.

10. A wired brake module (2), comprising a drive motor (22), a first electronic control unit (21) communicably connected to the drive motor (22), The main push rod (23) drivingly connected to the drive motor (22); A master brake cylinder (28) including a main piston (24) and an auxiliary piston (25); The main piston (24) and the auxiliary piston (25) that divide the master brake cylinder (28) into a first chamber (271) and a second chamber (272); Comprising; Comprising a first return spring (291) between the main piston (24) and the auxiliary piston (25); A second return spring (292) between the auxiliary piston (25) and the end wall of the master brake cylinder (28); Comprising; When the main piston (24) is in the initial position, it contacts the main push rod (23); The first chamber (271) and the second chamber (272) each communicate with the storage portion (26); When the first electronic control unit (21) receives a brake request from the electronic brake pedal (1), the following method: Controlling the drive motor (22) to drive the main piston (24) forward in the master brake cylinder (28) to compress the brake fluid in the master brake cylinder (28); Estimating whether the current forward stroke of the main piston (24) can satisfy the brake request, and if the result is affirmative, executing the current forward stroke until the brake request is satisfied; If the result is negative, the following steps: Executing the current forward stroke until the stroke of the main piston (24) exceeds a predetermined threshold, and then transmitting a first signal to the electronic stability module (3) of the vehicle body to notify it to disconnect the master brake cylinder (28) from each of the sub-brake cylinders (41, 42, 43, 44); Retracting the main piston (24) until the master brake cylinder (28) communicates with the storage portion (26), and enabling the brake fluid from the storage portion (26) to replenish the master brake cylinder (28); Advance the main piston (24) again and transmit a second signal to the electronic stability module (3) of the vehicle body to notify it to control the reconnection of each of the sub-brake cylinders (41, 42, 43, 44) of the master brake cylinder (28). A wired brake module (2) configured to perform the above.

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