Stability detection method, device and equipment of layshaft brake and storage medium

Abstract

The application provides a kind of method, device and equipment for detecting stability of layshaft brake and storage medium, it is related to transmission detection technical field.The method comprises: determining the output shaft target speed and target time length of the electric control mechanical automatic transmission to be detected;Adjust the gear position of electric control mechanical automatic transmission to be preset gear position, and adjust the speed of transmission output shaft of electric control mechanical automatic transmission to be output shaft target speed;Control the layshaft brake to execute multiple brake cycles, and obtain the output shaft torque of transmission output shaft corresponding to each brake cycle in brake phase, so as to determine the stability of layshaft brake according to the multiple output shaft torques obtained, wherein, in brake phase, the brake time length of layshaft brake is target time length.The method of the application solves the problem that the current electric control mechanical automatic transmission detection equipment does not have the stability detection function of layshaft brake due to the difficulty in extracting the friction work generated by layshaft brake.

Description

Technical Field

[0001] This application relates to the field of transmission testing, and in particular to a method, apparatus, equipment and storage medium for testing the stability of a countershaft brake. Background Technology

[0002] The countershaft brake is used in Automated Mechanical Transmission (AMT). The function of the countershaft brake is to brake during AMT shifting, generate friction work to reduce the speed of the countershaft of the transmission, thereby bringing the speed of the gear ring to be engaged on the output shaft of the transmission close to that of the engagement sleeve, thus quickly shifting into the gear, avoiding gear grinding, reducing shifting shock, and improving shifting quality.

[0003] During the braking phase of the secondary axle brake, reduced stability of the secondary axle brake can lead to brake failure, resulting in insufficient frictional work and severely impacting vehicle power and comfort. Therefore, the stability of the secondary axle brake needs to be tested before the AMT product is put into trial production.

[0004] Because the frictional work generated by the countershaft brake is difficult to extract, current AMT testing equipment does not have the function of detecting the stability of the countershaft brake. The stability detection of the countershaft brake is an urgent problem to be solved. Summary of the Invention

[0005] This application provides a method, apparatus, device, and storage medium for detecting the stability of a secondary shaft brake, in order to solve the problem that current AMT testing equipment does not have the function of detecting the stability of the secondary shaft brake because the frictional work generated by the secondary shaft brake is difficult to extract.

[0006] In a first aspect, this application provides a method for detecting the stability of a secondary shaft brake, the method comprising:

[0007] Determine the target rotational speed and target duration of the output shaft of the electromechanical automatic transmission to be tested;

[0008] Adjust the gear of the electromechanical automatic transmission to the preset gear, and adjust the speed of the output shaft of the electromechanical automatic transmission to the target speed of the output shaft;

[0009] The secondary shaft brake is controlled to perform multiple braking cycles, and the output shaft torque of the transmission output shaft corresponding to the braking phase of each braking cycle is obtained, so as to determine the stability of the secondary shaft brake based on the obtained multiple output shaft torques. In the braking phase, the braking duration of the secondary shaft brake is the target duration.

[0010] In one possible design, the countershaft brake is controlled to perform multiple braking cycles, and the output shaft torque of the transmission output shaft corresponding to the braking phase of each braking cycle is obtained, including:

[0011] In each braking cycle, the countershaft brake is controlled to apply the brakes;

[0012] Obtain the output shaft torque of the transmission output shaft;

[0013] When the braking duration reaches the target duration, the control pinion brake stops braking.

[0014] In one possible design, the method further includes, before controlling the countershaft brake to apply the brakes:

[0015] The solenoid valve of the countershaft brake of the electromechanical automatic transmission is turned on to control the braking of the countershaft brake;

[0016] Before controlling the countershaft brake to stop braking, the method further includes:

[0017] The solenoid valve of the control pinion brake is disconnected to control the pinion brake to stop braking;

[0018] Obtain the output shaft torque of the transmission output shaft, including:

[0019] The output shaft torque is obtained from a torque sensor located on the transmission output shaft.

[0020] In one possible design, before adjusting the gear of the electromechanical automatic transmission to a preset gear, the method further includes:

[0021] The solenoid valve of the gear selection actuator of the electromechanical automatic transmission is turned on until the gear is adjusted to the preset gear. The solenoid valve of the gear selection actuator is used to control the gear selection actuator of the electromechanical automatic transmission, and the gear selection actuator is used to adjust the gear.

[0022] In one possible design, the method further includes, before controlling the countershaft brake to perform multiple braking cycles:

[0023] The target speed of the input shaft is determined based on the target speed of the output shaft and the preset gear. The target speed of the input shaft refers to the speed of the input shaft of the electromechanical automatic transmission when the speed of the output shaft is the target speed of the output shaft.

[0024] The input shaft speed is obtained from a first speed sensor, and the output shaft speed is obtained from a second speed sensor, wherein the first speed sensor is located on the transmission input shaft and the second speed sensor is located on the transmission output shaft;

[0025] If the output shaft speed and the target output shaft speed are the same, and the input shaft speed and the target input shaft speed are the same, then the secondary shaft brake is controlled to perform multiple braking cycles.

[0026] In one possible design, after obtaining the output shaft torque of the transmission output shaft corresponding to the braking phase of each braking cycle, the method further includes:

[0027] Determine whether the torque of a consecutive preset number of output shafts is less than a preset torque;

[0028] If so, output indication information, which is used to indicate that the stability of the countershaft brake has decreased.

[0029] In one possible design, before adjusting the speed of the output shaft of the electromechanical automatic transmission to the target output shaft speed, the method further includes:

[0030] The motor speed is adjusted to the target output shaft speed, and the transmission output shaft speed is adjusted to the target output shaft speed. The motor and transmission output shaft are connected by a coupling.

[0031] Secondly, this application provides a stability detection device for a countershaft brake, comprising:

[0032] The determination module is used to determine the target rotational speed and target duration of the output shaft of the electromechanical automatic transmission to be tested;

[0033] The adjustment module is used to adjust the gear of the electromechanical automatic transmission to the preset gear and adjust the speed of the transmission output shaft of the electromechanical automatic transmission to the target speed of the output shaft.

[0034] The control module is used to control the secondary shaft brake to perform multiple braking cycles and obtain the output shaft torque of the transmission output shaft corresponding to the braking stage of each braking cycle, so as to determine the stability of the secondary shaft brake based on the obtained multiple output shaft torques. In the braking stage, the braking duration of the secondary shaft brake is the target duration.

[0035] Thirdly, this application provides a stability testing device for a secondary shaft brake, which is used to implement the stability testing method for a secondary shaft brake as described in the first aspect and various possible implementations of the first aspect.

[0036] The equipment includes: a motor, a base, a control cabinet, and an operating console;

[0037] The electromechanical automatic transmission to be tested is fixed on the base. The input shaft of the electromechanical automatic transmission is equipped with a first speed sensor, and the output shaft of the electromechanical automatic transmission is equipped with a torque sensor and a second speed sensor. The electromechanical automatic transmission includes: a shift actuator solenoid valve and a countershaft brake solenoid valve.

[0038] The electric motor is fixed to the base, and the output shaft of the electric motor and the output shaft of the gearbox are connected by a coupling.

[0039] The control cabinet is communicatively connected to both the torque sensor and the motor.

[0040] The control panel includes: a server, a test tool that communicates with the server, and a control unit that communicates with the test tool;

[0041] The control unit is connected to the control cabinet, the first speed sensor, the second speed sensor, the solenoid valve of the gear shifting actuator, and the solenoid valve of the countershaft brake.

[0042] Fourthly, this application provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the stability detection method for a secondary shaft brake as described in the first aspect and various possible implementations of the first aspect.

[0043] Fifthly, this application provides a computer program product, including a computer program, which, when executed by a processor, is used to implement the stability detection method for a secondary shaft brake as described in the first aspect and various possible implementations of the first aspect.

[0044] This application provides a method, apparatus, device, and storage medium for detecting the stability of a countershaft brake. By controlling the countershaft brake to execute multiple braking cycles, within each braking cycle, the frictional work generated by the countershaft brake is quantified based on the output shaft torque of the transmission output shaft, thereby determining the stability of the countershaft brake based on multiple output shaft torque values. This method achieves the following technical effects: quantifying the frictional work by the output shaft torque and acquiring the output shaft torque through a zero-valued torque sensor solves the problem of extracting the frictional work generated by the countershaft brake; determining whether the braking performance of the countershaft brake has failed by continuously measuring the output shaft torque, thus determining the stability of the countershaft brake, solves the problem of countershaft brake stability detection; the detection equipment has a simple structure, is easy to install and disassemble, and requires processing relatively little data, improving the practicality of the detection equipment. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 A schematic diagram of the structure of the stability testing device for the countershaft brake provided in the embodiments of this application;

[0047] Figure 2 A flowchart illustrating the stability detection method for the countershaft brake provided in this application embodiment. Figure 1 ;

[0048] Figure 3 A flowchart illustrating the stability detection method for the countershaft brake provided in this application embodiment. Figure 2 ;

[0049] Figure 4 A flowchart illustrating the stability detection method for the countershaft brake provided in this application embodiment. Figure 3 ;

[0050] Figure 5 A flowchart illustrating the stability detection method for the countershaft brake provided in this application embodiment. Figure 4 ;

[0051] Figure 6 This is a schematic diagram of the structure of the stability detection device for the countershaft brake provided in the embodiments of this application.

[0052] Figure label:

[0053] 10-Electro-mechanical automatic transmission; 11-Transmission input shaft; 12-Counter shaft brake; 13-Transmission countershaft; 14-Shift actuator; 15-Transmission output shaft; 16-Shift actuator solenoid valve; 17-Counter shaft brake solenoid valve;

[0054] 20-Testing equipment; 21-Motor; 22-Base; 23-Control cabinet; 24-Operating console; 241-Server; 242-Testing tool; 243-Control unit;

[0055] 31-Coupling; 32-Torque sensor; 33-Second speed sensor; 34-First speed sensor;

[0056] 40 - Stability detection device for the secondary shaft brake; 41 - Determination module; 42 - Adjustment module; 43 - Control module. Detailed Implementation

[0057] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0058] In the embodiments of this application, the terms "first" and "second" are used to distinguish identical or similar items with substantially the same function and effect. For example, a first speed sensor and a second speed sensor are used only to distinguish different speed sensors and do not limit their order. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" do not necessarily imply that they are different. It should be noted that in the embodiments of this application, the words "exemplary" or "for example" are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design scheme described as "exemplary" or "for example" in this application should not be construed as being better or more advantageous than other embodiments or design schemes. Specifically, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner. In the embodiments of this application, "at least one" means one or more, and "more than one" means two or more.

[0059] It should be noted that the phrase "at...time" in the embodiments of this application can refer to the instant at which a certain situation occurs, or to a period of time after the occurrence of a certain situation; the embodiments of this application do not specifically limit this. Furthermore, the stability detection of the secondary shaft brake provided in the embodiments of this application is merely an example, and the stability detection method for the secondary shaft brake may include more or fewer elements.

[0060] To facilitate a clear description of the technical solutions in the embodiments of this application, some terms and technologies involved in the embodiments of this application will be briefly introduced below:

[0061] Automated Mechanical Transmission (AMT): This refers to a stepped mechanical automatic transmission that is based on a manual mechanical transmission (MT) and equipped with an automatic shift control system (ASCS). This transforms the manual shifting mechanism into an automatic shifting mechanism, thereby achieving automatic gear shifting.

[0062] Sub-shaft brake: This refers to the brake installed on the AMT sub-shaft (or intermediate shaft). The ASCS controls the sub-shaft brake through a sub-shaft brake solenoid valve.

[0063] Gear selection actuator: This refers to the mechanism that enables gear selection and shifting in an AMT (Automated Manual Transmission System). The ASCS (Automatic Steering Control System) controls the gear selection actuator via a solenoid valve.

[0064] When a vehicle equipped with an AMT (Automated Manual Transmission) is in motion, the AMT shifts gears based on vehicle speed and accelerator pedal opening. During gear shifting, the shift actuator controls the engagement sleeve to move towards the gear ring to engage. If the rotational speed of the gear ring is significantly higher than that of the engagement sleeve, gear grinding can occur. Therefore, it is necessary to reduce the rotational speed of the gear ring to avoid gear grinding. Since the gear ring is mounted on the transmission output shaft via bearings and meshes with gears on the transmission countershaft, reducing the rotational speed of the transmission countershaft will reduce the rotational speed of the gear ring.

[0065] Normally, the speed of the transmission's secondary shaft is reduced by the secondary shaft brake. The specific principle is as follows: the ASCS controls the secondary shaft brake solenoid valve to open, and then controls the secondary shaft brake to brake through electro-pneumatic, electro-hydraulic, or electro-electric means, generating friction work to reduce the speed of the transmission's secondary shaft; when the speed of the transmission's secondary shaft is reduced to the target speed, that is, when the speed of the gear ring to be engaged is close to the speed of the engagement sleeve, the ASCS controls the secondary shaft brake solenoid valve to open, so as to control the secondary shaft brake to stop braking.

[0066] After prolonged braking, the stability of the countershaft brake decreases, severely impacting vehicle power and comfort. Therefore, it's necessary to test the stability of the countershaft brake; typically, a decrease in stability is determined when the brake's braking performance fails. The AMT (Automated Manual Transmission) obtains kinetic energy from the engine output via the clutch. During gear shifts, the driven end of the clutch disengages from the driving end, and the AMT cannot obtain kinetic energy from the engine. At this time, the countershaft brake reduces the speed of the transmission's countershaft through friction braking. Friction work W T It can effectively characterize the stability of the countershaft brake. When the stability of the countershaft brake decreases, the frictional work W T Decrease, therefore, according to the friction work W T Determine the stability of the secondary shaft brake.

[0067] However, during the actual testing process, it was found that due to the frictional work W T Difficult to extract, therefore the frictional work W is quantified by the output shaft torque of the transmission output shaft. T In other words, when the gear position of the AMT is determined, the transmission ratio between the transmission output shaft and the transmission countershaft is known. Based on the transmission ratio and the output shaft torque, the torque of the countershaft brake is determined, and thus the friction work W is determined. TMeanwhile, the AMT's structure is compact and complex, making it impractical to remove the countershaft brake from the AMT, test it, and then reinstall it. Therefore, a dedicated testing device is needed to test the stability of the countershaft brake based on the output shaft torque without damaging the overall AMT structure.

[0068] Based on this, embodiments of this application provide a method, apparatus, device, and storage medium for detecting the stability of a countershaft brake, which can be used in the field of transmission testing technology. In these embodiments, the countershaft brake is controlled to perform multiple braking cycles, and the frictional work generated by the countershaft brake is quantified by the output shaft torque of the transmission output shaft, so as to determine the stability of the countershaft brake based on the multiple output shaft torque values. This solves the problem that current testing equipment for electromechanical automatic transmissions lacks the function of detecting the stability of the countershaft brake because the frictional work generated by the countershaft brake is difficult to extract.

[0069] Figure 1 This is a schematic diagram of the structure of a stability testing device for a secondary shaft brake provided in an embodiment of this application. The testing device is used to implement a stability testing method for the secondary shaft brake. It should be noted that... Figure 1 The examples shown are merely examples of system architectures that can be applied to the embodiments of this application, in order to help those skilled in the art understand the technical content of this application, but do not mean that the embodiments of this application cannot be used in other devices, systems, environments or scenarios.

[0070] like Figure 1 As shown, the testing equipment 20 includes: a motor 21, a base 22, a control cabinet 23, and an operating table 24;

[0071] Specifically, the structure of the testing equipment 20 is relatively simple. It can be a device specifically designed to test the stability of the countershaft brake 12, or it can be an improvement based on existing transmission testing equipment.

[0072] The electromechanical automatic transmission 10 to be tested is fixed on the base 22. The transmission input shaft 11 of the electromechanical automatic transmission 10 is equipped with a first speed sensor 34, and the transmission output shaft 15 of the electromechanical automatic transmission 10 is equipped with a torque sensor 32 and a second speed sensor 33. The electromechanical automatic transmission 10 includes: a shift actuator solenoid valve 16 and a countershaft brake solenoid valve 17.

[0073] Specifically, the base 22 can secure the electromechanical automatic transmission 10 in various ways, including but not limited to clamp fixation and angle fixation. The base 22 is used to ensure that the electromechanical automatic transmission 10 will not vibrate or shift during the testing process.

[0074] The torque sensor 32 can be a sensor for acquiring torque, including but not limited to inductive and metal resistance strain gauge types. The torque sensor 32 is used to monitor and acquire the output shaft torque of the transmission output shaft 15.

[0075] The first speed sensor 34 can be a sensor for acquiring speed, including but not limited to electromagnetic, photoelectric, and Hall effect sensors. The first speed sensor 34 is used to monitor and acquire the input speed of the transmission input shaft 11.

[0076] The second speed sensor 33 is similar to the first speed sensor 34, and will not be described again here. The second speed sensor 33 is used to monitor and acquire the output shaft speed of the transmission output shaft 15.

[0077] The gear shifting actuator solenoid valve 16 can be a direct-acting solenoid valve. When the gear shifting actuator solenoid valve 16 is turned on, the gear shifting actuator 14 is controlled to select and shift gears by means of electro-pneumatic, electro-hydraulic or electro-electric control.

[0078] The countershaft brake solenoid valve 17 can be a direct-acting solenoid valve. When the countershaft brake solenoid valve 17 is turned on, the countershaft brake 12 is controlled to brake by means of electro-pneumatic, electro-hydraulic or electro-electric control, so as to reduce the speed of the countershaft 13 of the transmission.

[0079] The motor 21 is fixed on the base 22, and the output shaft of the motor 21 and the output shaft 15 of the gearbox are connected by a coupling 31.

[0080] Specifically, the way and function of fixing the electric motor 21 on the base 22 are similar to those of fixing the electromechanical automatic transmission 10, and will not be described in detail here.

[0081] The electric motor 21 can be a variable frequency motor, including but not limited to a three-phase asynchronous motor, a DC brushless motor, an AC brushless motor, etc. The electric motor 21 enables the output shaft 15 of the gearbox to reach the target output shaft speed, thereby enabling the input shaft 11 of the gearbox to reach the target input shaft speed.

[0082] The reason why the electric motor 21 is connected to the transmission output shaft 15 instead of the transmission input shaft 11 is that the transmission input shaft 11 is connected to the driven end of the clutch, which is more complex. Connecting the electric motor 21 to the transmission input shaft 11 would increase the time for AMT installation and removal.

[0083] The coupling 31 can be a rigid coupling, including but not limited to flange couplings, sleeve couplings, and clamp couplings. The coupling 31 can ensure a high degree of alignment between the output shaft of the motor 21 and the output shaft 15 of the gearbox, and can transmit a large torque, making it widely used.

[0084] Control cabinet 23 is communicatively connected to torque sensor 32 and motor 21 respectively;

[0085] Specifically, the control cabinet 23 can be a motor control cabinet with a built-in display screen, used to adjust the speed of the motor 21, and also to acquire and display the torque of multiple output shafts sent by the torque sensor 32, so that the testing personnel can determine the stability of the secondary shaft brake 12 based on the multiple output shaft torques.

[0086] Communication lines can be various types of buses, including but not limited to Controller Area Network (CAN) and Local Interconnect Network (LIN). Communication lines are used to transmit control information and also parameter information.

[0087] The control panel 24 includes: a server 241, a test tool 242 that is connected to the server 241, and a control unit 243 that is connected to the test tool 242. The control unit 243 is connected to the control cabinet 23, the first speed sensor 34, the second speed sensor 33, the gear shifting actuator solenoid valve 16, and the countershaft brake solenoid valve 17.

[0088] Specifically, server 241 can be an electronic device for data processing, including but not limited to portable computers and desktop computers. Server 241 is used to determine the rotational speed of the transmission output shaft 15 and the braking time of the countershaft brake 12 in each braking cycle based on the parameters and preset gear of the electromechanical automatic transmission 10; the control panel 24 is also used to determine whether to control the countershaft brake 12 to brake based on the output shaft speed and the input shaft speed.

[0089] Test tool 242 can be a test instrument that assists in testing, including but not limited to the CANcase data tester. Test tool 242 is used to perform data format conversion, such as converting data to binary format, batch format, or text format.

[0090] The control unit 243 can be various types of microcomputer systems, including but not limited to embedded microprocessors, single-board computers, and microcontrollers. The control unit 243 is used to control the on / off state of the shift actuator solenoid valve 16 and the countershaft brake solenoid valve 17, and also to acquire the input shaft speed sent by the first speed sensor 34 and the output shaft speed sent by the second speed sensor 33, and transmit the output shaft speed and input shaft speed to the server 241.

[0091] Furthermore, the control cabinet 23 can send the output shaft torque to the control unit 243 so that the server 241 can obtain and process the output shaft torque to determine whether to output indication information; the control cabinet 23 can also obtain the output shaft speed from the server 241 through the control unit 243 and control the speed of the motor 21 to be the output shaft speed.

[0092] Figure 2 A flowchart illustrating the stability detection method for the countershaft brake provided in this application embodiment. Figure 1 .like Figure 2 As shown, in this embodiment... Figure 1 Based on the system architecture, a stability detection method for the secondary shaft brake is described in detail. This embodiment provides a stability detection method for the secondary shaft brake, including:

[0093] S101. Determine the target rotational speed and target duration of the output shaft of the electromechanical automatic transmission to be tested;

[0094] Specifically, when an AMT is installed in a vehicle, the frictional work W generated during AMT gear shifting... T for:

[0095] W T =T3×θ3

[0096] Where T3 is the secondary shaft torque of the secondary shaft brake, i.e., the friction torque, and θ3 is the friction angle through which the friction pad of the secondary shaft brake rotates relative to the brake pad. The friction angle θ is:

[0097] θ=w3×t

[0098] Where w3 is the target angular velocity of the countershaft before shifting gears, and t is the target duration.

[0099] According to the law of conservation of energy, the frictional work W generated by the secondary shaft brake is... T This is equal to the kinetic energy loss of the secondary shaft brake, that is:

[0100]

[0101] Where J is the equivalent moment of inertia of the transmission during braking, w t3 This is the target angular velocity of the countershaft braking after gear shifting.

[0102] According to Newton's second law, we know that:

[0103] T3=Jα3

[0104] Where α3 is the angular acceleration of the secondary shaft when the secondary shaft brake is applied.

[0105] From the above formula, we can see that:

[0106]

[0107] The specific process for determining the target output shaft speed n2 is as follows:

[0108] Based on the engaged gear, the first transmission ratio i between the transmission input shaft and the transmission countershaft is obtained. 13 and the second transmission ratio i between the transmission countershaft and the transmission output shaft. 23 ;

[0109] According to the AMT's preset shift curve, the engine angular velocity before shifting is known, i.e., the target angular velocity w1 of the input shaft.

[0110] According to the first transmission ratio i 13 Second transmission ratio i 23 The input shaft target angular velocity w1 is used to determine the secondary shaft target angular velocity w3 and the output shaft target angular velocity w2, which are then converted into the output shaft target rotational speed n2.

[0111] Based on this, the specific process for determining the target duration t is as follows:

[0112] After the AMT gear shift is completed, the target braking speed n of the input shaft after the shift is obtained through the speed sensor located on the transmission input shaft. t1 And convert it into the input shaft braking target angular velocity w t1 ;

[0113] The angular acceleration α1 of the transmission input shaft after a gear shift is obtained by using an angular acceleration sensor located on the transmission input shaft.

[0114] According to the first transmission ratio i 13 and the input shaft braking target angular velocity w t1 The target angular velocity w of the secondary shaft braking can be calculated. t3 ;

[0115] According to the first transmission ratio i 13 Given the input shaft angular acceleration α1, the secondary shaft angular acceleration α3 can be calculated, and then the target duration t can be determined.

[0116] S102. Adjust the gear of the electromechanical automatic transmission to the preset gear, and adjust the speed of the output shaft of the electromechanical automatic transmission to the target speed of the output shaft.

[0117] Specifically, the AMT gear is adjusted to the preset gear, and this preset gear is maintained throughout the testing process. Simultaneously, the transmission output shaft speed is adjusted to the target output shaft speed w2. This is because the frictional work W generated by the countershaft brake increases after the AMT gear and the transmission output shaft speed change. TThis leads to changes that make it impossible to determine the stability of the secondary shaft brake based on the multiple output shaft torques T2 obtained.

[0118] Considering that in practical applications, the transmission ratio of AMT is relatively large and the difference in the speed of the transmission output shaft before and after shifting is not significant, in order to simplify the testing process, the speed of the transmission output shaft is always controlled to be the target speed w2.

[0119] S103. Control the secondary shaft brake to execute multiple braking cycles, and obtain the output shaft torque of the transmission output shaft corresponding to the braking stage of each braking cycle, so as to determine the stability of the secondary shaft brake based on the obtained multiple output shaft torques. In the braking stage, the braking duration of the secondary shaft brake is the target duration.

[0120] Specifically, the countershaft brake is controlled to perform multiple braking cycles. Each braking cycle includes a braking phase and a non-braking phase. During the braking phase, the countershaft brake continuously applies the brakes for a target duration. During the non-braking phase, the countershaft brake stops applying the brakes until the next braking cycle begins. The purpose of this is to simulate a real shifting environment on the testing equipment and perform numerous braking simulations to determine whether the stability of the countershaft brake still meets the preset conditions after multiple braking simulations.

[0121] The output shaft torque can be obtained through a torque sensor. However, during the detection process, an external electric motor drives the transmission output shaft to rotate, at which point the transmission output shaft possesses a certain torque. Therefore, before controlling the countershaft brake, the torque sensor is set to zero so that the torque obtained by the torque sensor can directly reflect the output shaft torque T. 3i .

[0122] Obtain the output shaft torque T corresponding to each braking stage. 3i The torque T of each output shaft is displayed one by one on the control cabinet's screen. 3i This is to facilitate testing personnel in determining the output shaft torque T. 3i The stability of the countershaft brake was determined. Extensive experiments revealed that when the countershaft brake failed, the output shaft torque decreased to 20% of its initial value after 10 consecutive cycles. Therefore, multiple output shaft torques T were monitored. 3i If this condition is met, it indicates that the stability of the output shaft is reduced.

[0123] Furthermore, the control cabinet will output shaft torque T 3i The data is sent to the server via the control unit, and the server determines the output shaft torque T based on this information. 3i Determine the stability of the secondary shaft brake.

[0124] The stability detection method for the secondary shaft brake provided in this embodiment controls the secondary shaft brake to perform multiple braking cycles. Within each braking cycle, the frictional work generated by the secondary shaft brake is quantified based on the output shaft torque of the transmission output shaft, thereby determining the stability of the secondary shaft brake based on multiple output shaft torque values. This method achieves the following technical effects: quantifying the frictional work by the output shaft torque and obtaining the output shaft torque through a zeroed torque sensor solves the problem of extracting the frictional work generated by the secondary shaft brake; determining whether the braking performance of the secondary shaft brake has failed by continuously measuring the output shaft torque, and thus determining the stability of the secondary shaft brake, solves the problem of secondary shaft brake stability detection; the detection equipment has a simple structure, is easy to install and disassemble, and requires processing relatively little data, improving the practicality of the detection equipment.

[0125] Figure 3 A flowchart illustrating the stability detection method for the countershaft brake provided in this application embodiment. Figure 2 .like Figure 3 As shown, in this embodiment... Figure 2 Based on the embodiments, the stability detection method of the countershaft brake is described in detail. The stability detection method of the countershaft brake provided in this embodiment includes:

[0126] S201. Determine the target rotational speed and target duration of the output shaft of the electromechanical automatic transmission to be tested;

[0127] S201 is similar to S101, and will not be described again in this embodiment.

[0128] S202. Adjust the speed of the motor to the target speed of the output shaft, and adjust the speed of the output shaft of the gearbox to the target speed of the output shaft.

[0129] Specifically, the control cabinet and the motor are connected via communication, and the control cabinet adjusts the motor speed to the target output shaft speed. The motor and the gearbox output shaft are connected via a coupling, and the motor drives the gearbox output shaft to the target output shaft speed.

[0130] S203. The solenoid valve of the gear shifting actuator of the electromechanical automatic transmission is turned on until the gear is adjusted to the preset gear.

[0131] Specifically, the control unit and the solenoid valve of the gear shifting actuator are communicatively connected. The control unit controls the solenoid valve of the gear shifting actuator to open. When the solenoid valve of the gear shifting actuator is open, the gear shifting actuator is controlled to select and shift gears through electro-pneumatic, electro-hydraulic, or electro-electric methods. When the AMT's gear is adjusted to the preset gear, the control unit controls the solenoid valve of the gear shifting actuator to close. When the testing equipment detects the stability of the AMT, the AMT's gear is always at the preset gear.

[0132] S204. Determine the target speed of the input shaft based on the target speed of the output shaft and the preset gear.

[0133] Specifically, the input shaft target speed refers to the speed of the input shaft of an electromechanical automatic transmission when the output shaft speed is at the output shaft target speed. After the gear position is determined in an AMT (Automated Manual Transmission), the first gear ratio i between the transmission input shaft and the transmission countershaft... 13 and the second transmission ratio i between the transmission countershaft and the transmission output shaft. 23 This can be determined based on the target output shaft speed and the second transmission ratio i. 23 The target speed of the countershaft can be determined; then, based on the target speed of the countershaft and the first transmission ratio i... 13 The target speed of the input shaft can be determined.

[0134] S205. Obtain the input shaft speed from the first speed sensor and the output shaft speed from the second speed sensor;

[0135] Specifically, the first speed sensor is located on the transmission input shaft, and the control unit obtains the input shaft speed from the first sensor; the second speed sensor is located on the transmission output shaft, and the control unit obtains the output shaft speed from the second sensor.

[0136] S206. If the output shaft speed and the target output shaft speed are the same, and the input shaft speed and the target input shaft speed are the same, then control the secondary shaft brake to perform multiple braking cycles.

[0137] Specifically, the control unit sends the acquired input shaft speed and output shaft speed to the server, which then determines whether the output shaft speed and the target output shaft speed are the same, and whether the input shaft speed and the target input shaft speed are the same.

[0138] If the output shaft speed and the target output shaft speed are the same, and the input shaft speed and the target input shaft speed are the same, then the detection device has completely simulated the braking scenario of the AMT (Automated Manual Transmission) in a vehicle. In this case, the processor determines that it can begin controlling the sub-shaft brake to execute multiple braking cycles.

[0139] If the output shaft speed and the target output shaft speed are not the same, and / or the input shaft speed and the target input shaft speed are not the same, it indicates that the detection equipment has not simulated the scenario of the AMT (Automated Manual Transmission) being used for braking in a vehicle. In this case, the processor determines that it cannot start controlling the sub-shaft brake to perform multiple braking cycles, and the control cabinet needs to readjust the motor speed until the output shaft speed and the target output shaft speed are the same, and the input shaft speed and the target input shaft speed are the same.

[0140] S207. Control the secondary shaft brake to perform multiple braking cycles and obtain the output shaft torque of the transmission output shaft corresponding to the braking stage of each braking cycle, so as to determine the stability of the secondary shaft brake based on the obtained multiple output shaft torques.

[0141] Specifically, the control unit controls the countershaft brake to perform multiple braking cycles, and in each braking cycle, the braking duration of the countershaft brake is controlled to the target duration. At the same time, during the braking phase of each braking cycle, the output shaft torque recorded by the torque sensor located on the transmission output shaft is collected. This torque sensor has been set to zero before braking.

[0142] Each time the control cabinet collects an output shaft torque, it displays that output shaft torque along with the previously collected output shaft torques on the control cabinet's display screen. The testing personnel use these output shaft torques to determine the stability of the secondary shaft brake.

[0143] The stability assessment criteria for the secondary shaft brake are obtained through numerous experiments based on the overall parameters of the AMT (Automated Manual Transmission), the current gear position of the AMT, and the output shaft speed before and after braking. For example, if the output shaft torque decreases to 20% of the initial output shaft torque after 10 consecutive increases, the secondary shaft brake is considered to have failed, meaning its stability has decreased.

[0144] Figure 4 A flowchart illustrating the stability detection method for the countershaft brake provided in this application embodiment. Figure 3 .

[0145] In this embodiment, each braking cycle includes a braking phase and a non-braking phase, such as... Figure 4 As shown, this embodiment is... Figure 3 Based on the embodiments, the braking phase of each braking cycle is described in detail. Accordingly, S207 includes:

[0146] S2071. The solenoid valve of the countershaft brake of the electromechanical automatic transmission is turned on to control the braking of the countershaft brake.

[0147] Specifically, the control unit is communicatively connected to the countershaft brake solenoid valve, and the control unit controls the countershaft brake solenoid valve to open. When the countershaft brake solenoid valve is open, the countershaft brake is controlled to brake via electro-pneumatic, electro-hydraulic, or electro-electric methods to reduce the speed of each shaft in the transmission. When the countershaft...

[0148] S2072. Obtain the output shaft torque from the torque sensor;

[0149] Specifically, the torque sensor is located on the transmission output shaft. The control cabinet obtains the output shaft torque corresponding to the current braking phase from the torque sensor and displays this output shaft torque on the display screen.

[0150] S2073. When the braking duration is the target duration, the control valve of the secondary shaft brake is disconnected to control the secondary shaft brake to stop braking.

[0151] Specifically, when the braking duration of the secondary shaft brake is the target duration, the control unit controls the secondary shaft brake solenoid valve to open; when the secondary shaft brake solenoid valve is open, the secondary shaft brake is controlled to stop braking by means of electro-pneumatic, electro-hydraulic or electro-electric control.

[0152] The period between the end of one braking phase and the start of the next is the non-braking phase of the current braking cycle. During the non-braking phase, the AMT's gear position and output shaft speed remain unchanged, and the secondary shaft brake stops braking. The purpose of the non-braking phase is to simulate the driving process between two adjacent gear shifts in a real-world driving environment. The duration of each non-braking phase is preset by the server and can be completely identical, completely different, or partially identical and partially different.

[0153] Figure 5 A flowchart illustrating the stability detection method for the countershaft brake provided in this application embodiment. Figure 4 .

[0154] In one possible design, the control cabinet acquires and displays multiple output shaft torques sent by the torque sensor, allowing the testing personnel to determine the stability of the secondary shaft brake based on these torques. Then, the multiple output shaft torques are sent to the control unit, enabling the server to determine the stability of the secondary shaft brake based on these torques. Accordingly, after S207, the method further includes:

[0155] S301. Determine whether the torque of a consecutive preset number of output shafts is less than the preset torque;

[0156] Specifically, the stability of the secondary shaft brake can be judged manually by inspectors or automatically by the control panel. When the stability of the secondary shaft brake is judged by the control panel, the control cabinet communicates with the control panel. Each time the control cabinet acquires an output shaft torque, it sends that output shaft torque to the control panel. The control panel automatically determines whether a preset number of consecutive output shaft torques are all less than a preset torque.

[0157] If so, it means that the torque of multiple output shafts meets the preset conditions, the secondary shaft brake fails, and S302 is executed;

[0158] If not, it means that multiple output shaft torques do not meet the preset conditions and the secondary shaft brake has not failed. Then, continue to execute S301, that is, continue to acquire new output shaft torques and make automatic judgments until a preset number of consecutive output shaft torques are all less than the preset torque, or the stability detection of the secondary shaft brake ends.

[0159] S302, Output indication information, which is used to indicate that the stability of the countershaft brake has decreased;

[0160] Specifically, if the control panel determines that the torque of a consecutive preset number of output shafts is less than a preset torque, it will display an indication message on the server's display interface and provide prompts according to the settings of the testing personnel. The indication message may include information such as reduced stability of the countershaft brake, or other similar messages.

[0161] The stability detection method for the secondary shaft brake provided in this embodiment controls the secondary shaft brake to perform multiple braking cycles. Within each braking cycle, the frictional work generated by the secondary shaft brake is quantified based on the output shaft torque of the transmission output shaft, thereby determining the stability of the secondary shaft brake based on multiple output shaft torque values. This method achieves the following technical effects: quantifying the frictional work by the output shaft torque and obtaining the output shaft torque through a zeroed torque sensor solves the problem of extracting the frictional work generated by the secondary shaft brake; determining whether the braking performance of the secondary shaft brake has failed by continuously measuring the output shaft torque, and thus determining the stability of the secondary shaft brake, solves the problem of secondary shaft brake stability detection; the detection equipment has a simple structure, is easy to install and disassemble, and requires less data processing, improving the practicality of the detection equipment; by driving the transmission output shaft to rotate with a motor, and then driving the transmission input shaft to rotate, and detecting whether the output shaft speed and input shaft speed have reached the corresponding target speed, the structure of the detection equipment is simplified, and the real shifting environment of an AMT is simulated; the newly added output shaft torque is displayed on the control cabinet screen, so that the testing personnel can determine the stability of the secondary shaft brake, or the stability of the secondary shaft brake can be automatically determined by the operating panel, solving the problem of determining the stability of the secondary shaft brake based on multiple output shaft torques.

[0162] In this embodiment of the invention, electronic devices or main control devices can be divided into functional modules according to the above method examples. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing unit. The integrated unit can be implemented in hardware or as a software functional module. It should be noted that the module division in this embodiment of the invention is illustrative and only represents one logical functional division; other division methods may be used in actual implementation.

[0163] Figure 6 This is a schematic diagram of the structure of the stability detection device for the countershaft brake provided in an embodiment of this application. Figure 6 As shown, the stability detection device 40 for the countershaft brake provided in this application embodiment includes: a determination module 41, an adjustment module 42, and a control module 43;

[0164] The determination module 41 is used to determine the target rotational speed and target duration of the output shaft of the electromechanical automatic transmission to be tested;

[0165] The adjustment module 42 is used to adjust the gear of the electromechanical automatic transmission to the preset gear and adjust the speed of the transmission output shaft of the electromechanical automatic transmission to the target speed of the output shaft.

[0166] The control module 43 is used to control the secondary shaft brake to perform multiple braking cycles and obtain the output shaft torque of the transmission output shaft corresponding to the braking stage of each braking cycle, so as to determine the stability of the secondary shaft brake based on the obtained multiple output shaft torques. In the braking stage, the braking duration of the secondary shaft brake is the target duration.

[0167] In one possible design, the control module 43 includes: a braking module and a first acquisition module;

[0168] The braking module is used to control the braking of the secondary shaft brake in each braking cycle;

[0169] The first acquisition module is used to acquire the output shaft torque of the transmission output shaft;

[0170] The braking module is also used to control the countershaft brake to stop braking when the braking duration is the target duration.

[0171] In one possible design, a braking module is used to control the conduction of the countershaft brake solenoid valve of the electromechanical automatic transmission to control the braking of the countershaft brake.

[0172] The braking module is also used to control the disengagement of the countershaft brake solenoid valve in order to control the countershaft brake to stop braking;

[0173] The first acquisition module is used to acquire the output shaft torque from a torque sensor, wherein the torque sensor is located on the transmission output shaft.

[0174] In one possible design, adjustment module 42 includes: a first adjustment module;

[0175] The first adjustment module is used to control the solenoid valve of the gear selection actuator of the electromechanical automatic transmission to be turned on until the gear is adjusted to the preset gear. The solenoid valve of the gear selection actuator is used to control the gear selection actuator of the electromechanical automatic transmission, and the gear selection actuator is used to adjust the gear.

[0176] In one possible design, the stability detection device 40 of the countershaft brake includes: a second acquisition module and an execution module;

[0177] The determination module is used to determine the target speed of the input shaft based on the target speed of the output shaft and the preset gear. The target speed of the input shaft refers to the speed of the input shaft of the electromechanical automatic transmission when the speed of the output shaft of the transmission is the target speed of the output shaft.

[0178] The second acquisition module is used to acquire the input shaft speed from the first speed sensor and the output shaft speed from the second speed sensor, wherein the first speed sensor is located on the transmission input shaft and the second speed sensor is located on the transmission output shaft;

[0179] The execution module is used to control the secondary shaft brake to perform multiple braking cycles if the output shaft speed and the target output shaft speed are the same, and the input shaft speed and the target input shaft speed are the same.

[0180] In one possible design, the stability detection device 40 of the countershaft brake includes: a judgment module;

[0181] The judgment module is used to determine whether the torque of a consecutive preset number of output shafts is less than the preset torque; if so, it outputs indication information, which is used to indicate that the stability of the countershaft brake has decreased.

[0182] In one possible design, adjustment module 42 includes: a second adjustment module;

[0183] The second adjustment module is used to adjust the speed of the motor to the target speed of the output shaft, so as to adjust the speed of the transmission output shaft to the target speed of the output shaft. The motor and the transmission output shaft are connected by a coupling.

[0184] In the specific implementation of the aforementioned stability detection method for the secondary shaft brake, each module can be implemented as a processor. The processor can execute computer execution instructions stored in the memory, so that the processor executes the stability detection method for the secondary shaft brake shown in the above method embodiment.

[0185] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the stability detection method for the secondary shaft brake as shown in the above method embodiments.

[0186] The aforementioned computer-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0187] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in an electronic device or a host device.

[0188] This application also provides a computer program product, comprising: a computer program stored in a readable storage medium, wherein at least one processor of an electronic device can read the computer program from the readable storage medium, and the at least one processor executes the computer program to cause the electronic device to perform the scheme provided in any of the above embodiments.

[0189] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disk, or optical disk.

[0190] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it is readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. The above 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 or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for detecting the stability of a secondary shaft brake, characterized in that, The method includes: Determine the target rotational speed and target duration of the output shaft of the electromechanical automatic transmission to be tested; Adjust the gear of the electromechanical automatic transmission to a preset gear, and adjust the speed of the output shaft of the electromechanical automatic transmission to the target speed of the output shaft; The system controls the secondary shaft brake to perform multiple braking cycles and acquires the output shaft torque of the transmission output shaft corresponding to the braking phase of each braking cycle, so as to determine the stability of the secondary shaft brake based on the acquired multiple output shaft torques. In the braking phase, the braking duration of the secondary shaft brake is the target duration. The output shaft torque is acquired from a torque sensor located on the transmission output shaft. When the secondary shaft brake is not braking, the torque sensor is set to zero. After obtaining the output shaft torque of the transmission output shaft corresponding to the braking phase of each braking cycle, the method further includes: Determine whether the torque of a consecutive preset number of output shafts is less than a preset torque; If so, output indication information, which is used to indicate that the stability of the secondary shaft brake has decreased.

2. The method according to claim 1, characterized in that, The process of controlling the secondary shaft brake to execute multiple braking cycles and obtaining the output shaft torque of the transmission output shaft corresponding to the braking phase of each braking cycle includes: In each braking cycle, the secondary shaft brake is controlled to apply the brakes; Obtain the output shaft torque of the transmission output shaft; When the braking duration is the target duration, the countershaft brake is controlled to stop braking.

3. The method according to claim 2, characterized in that, Before controlling the secondary shaft brake to brake, the method further includes: The solenoid valve of the countershaft brake of the electromechanical automatic transmission is turned on to control the braking of the countershaft brake; Before controlling the secondary shaft brake to stop braking, the method further includes: The solenoid valve of the secondary shaft brake is disconnected to control the secondary shaft brake to stop braking; The step of obtaining the output shaft torque of the transmission output shaft includes: The output shaft torque is obtained from a torque sensor located on the output shaft of the transmission.

4. The method according to claim 3, characterized in that, Before adjusting the gear of the electromechanical automatic transmission to a preset gear, the method further includes: The solenoid valve of the gear selection actuator of the electromechanical automatic transmission is controlled to be turned on until the gear is adjusted to the preset gear. The solenoid valve of the gear selection actuator is used to control the gear selection actuator of the electromechanical automatic transmission, and the gear selection actuator is used to adjust the gear.

5. The method according to claim 4, characterized in that, Before controlling the secondary shaft brake to perform multiple braking cycles, the method further includes: The target speed of the input shaft is determined based on the target speed of the output shaft and the preset gear. The target speed of the input shaft refers to the speed of the input shaft of the electromechanical automatic transmission when the speed of the output shaft of the transmission is the target speed of the output shaft. The input shaft speed is obtained from a first speed sensor, and the output shaft speed is obtained from a second speed sensor, wherein the first speed sensor is located on the input shaft of the transmission, and the second speed sensor is located on the output shaft of the transmission; If the output shaft speed is the same as the target output shaft speed, and the input shaft speed is the same as the target input shaft speed, then the secondary shaft brake is controlled to execute the multiple braking cycles.

6. The method according to claim 1, characterized in that, Before adjusting the rotational speed of the output shaft of the electromechanical automatic transmission to the target rotational speed of the output shaft, the method further includes: The speed of the motor is adjusted to the target speed of the output shaft, thereby adjusting the speed of the transmission output shaft to the target speed of the output shaft, wherein the motor and the transmission output shaft are connected by a coupling.

7. A stability detection device for a secondary shaft brake, characterized in that, The device includes: The determination module is used to determine the target rotational speed and target duration of the output shaft of the electromechanical automatic transmission to be tested; The adjustment module is used to adjust the gear of the electromechanical automatic transmission to a preset gear and adjust the speed of the transmission output shaft of the electromechanical automatic transmission to the target speed of the output shaft. The control module is used to control the secondary shaft brake to perform multiple braking cycles and to acquire the output shaft torque of the transmission output shaft corresponding to the braking phase of each braking cycle, so as to determine the stability of the secondary shaft brake based on the acquired multiple output shaft torques. In the braking phase, the braking duration of the secondary shaft brake is the target duration. The output shaft torque is acquired from a torque sensor located on the transmission output shaft. When the secondary shaft brake is not braking, the torque sensor is set to zero. The judgment module is used to determine whether the torque of a consecutive preset number of output shafts is less than a preset torque; If so, output indication information, which is used to indicate that the stability of the secondary shaft brake has decreased.

8. A stability testing device for a secondary shaft brake, characterized in that, The device is used to implement a stability detection method for a secondary shaft brake as described in any one of claims 1 to 6; The equipment includes: a motor, a base, a control cabinet, and an operating console; The electromechanical automatic transmission to be tested is fixed on the base. The input shaft of the electromechanical automatic transmission is equipped with a first speed sensor, and the output shaft of the electromechanical automatic transmission is equipped with a torque sensor and a second speed sensor. The electromechanical automatic transmission includes: a shift actuator solenoid valve and a countershaft brake solenoid valve. The electric motor is fixed on the base, and the output shaft of the electric motor and the output shaft of the transmission are connected by a coupling; The control cabinet is communicatively connected to the torque sensor and the electric motor, respectively. The control panel includes: a server, a test tool communicatively connected to the server, and a control unit communicatively connected to the test tool; The control unit is communicatively connected to the control cabinet, the first speed sensor, the second speed sensor, the gear shifting actuator solenoid valve, and the countershaft brake solenoid valve.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement a stability detection method for a secondary shaft brake as described in any one of claims 1 to 6.

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