Electronic mechanical parking mechanism with toothed disc and method for predicting its lifetime

Abstract

The application relates to a tooth disc type electronic mechanical parking mechanism and a service life prediction method thereof. The tooth disc type electronic mechanical parking mechanism comprises a static disc and a locking mechanism. The locking mechanism comprises a dynamic disc and a linear driving mechanism. A ratchet structure is arranged between the dynamic disc and the static disc. The linear driving mechanism comprises a helical gear and a rotary driving mechanism. The dynamic disc is fixed on an end face of the helical gear. The helical gear is installed on a shell of an EMB reducer through a sliding connection structure. The rotary driving mechanism comprises a motor and a worm. The worm is installed on a main shaft of the motor. The worm and the helical gear are vertically staggered and arranged in meshing. The worm and the helical gear in the tooth disc type electronic mechanical parking mechanism have a reverse self-locking function. After parking is completed, the motor does not need to be continuously powered, and the tooth disc type electronic mechanical parking mechanism has the advantages of compact structure, low energy consumption and convenient deployment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle control, in particular to a tooth disc type electronic mechanical parking mechanism and a tooth disc type electronic mechanical parking mechanism service life prediction method thereof. BACKGROUND

[0002] Drive-by-wire chassis is the guarantee of landing high-level automatic driving technology, and drive-by-wire brake system is the most critical system of drive-by-wire chassis. Electro-mechanical brakes (EMB) have the advantages of zero drag, fast response speed, high control precision and convenient maintenance, and are the mainstream of future automobile drive-by-wire systems. EMB completely abandons the liquid gas pressure device, and realizes real drive-by-wire braking.

[0003] Traditional automobile parking mechanisms include mechanical pull lock type and electronic mechanical parking brake (EPB), and these parking mechanisms need complex mechanical structures and pressure pipelines (gas pressure or hydraulic pressure) to realize parking. However, it is imperative to deploy a parking mechanism on the EMB system to realize the parking function. As we know, the EMB actuator usually uses a ball screw, a force amplification mechanism or a trapezoidal screw rod alone or in combination as a motion conversion mechanism to convert the rotary motion of the reducer into translation to push the brake pad to brake. It is worth noting that no matter which motion conversion mechanism is used, it does not have a self-locking function. Therefore, the parking mechanism is an important part of the EMB.

[0004] Currently, researchers have proposed many excellent parking mechanisms that can be deployed in EMB actuators, among which the mainstream parking mechanisms include ratchet pawl type parking mechanism, disc friction type parking mechanism and electromagnetic clutch type; the invention patent application with application publication number CN115817440 A and application publication number CN117227688 A realize parking by combining a ratchet pawl with an electromagnetic valve; the utility model patent with authorized announcement number CN221610450U realizes parking by using a friction disc; and the invention patent application with application publication number CN115853935A uses an electromagnetic clutch to wrap around the drive shaft of the EMB motor, and clamps the drive shaft of the EMB motor by energizing the electromagnetic clutch, so as to realize parking by friction.

[0005] However, the mainstream parking mechanisms proposed above have obvious deficiencies. For example, the ratchet pawl type parking mechanism needs to use an electromagnetic valve to push the pawl to be clamped into the ratchet groove when parking, and the pawl needs to be accurately clamped into the ratchet groove to meet the parking force, which is complex to control. The friction disc type parking mechanism usually has patterns on the friction pair to increase the friction force. However, after a long time of static friction, the patterns will be worn out, which may cause the parking mechanism to fail, or even cause a safety accident such as a car slipping and injuring people. The deficiencies of the electromagnetic clutch type parking mechanism are as follows: on the one hand, the power density of the electromagnetic clutch is small, and to achieve the parking brake torque, the size of the electromagnetic clutch will become very large, which leads to deployment difficulties, and does not meet the application requirements of the wire-controlled intelligent chassis. In addition, the electromagnetic brake needs to be continuously powered in the driving brake working condition to keep it loose, so it cannot meet the design standard of low energy consumption. On the other hand, during driving, the electromagnetic brake needs to be powered to loosen it, and at the same time, the EMB actuator needs to be braked. The whole control process is extremely complex, and it puts high requirements on the response time and service life of the electromagnetic brake.

[0006] In summary, the mainstream parking mechanism still has many problems to be solved. Therefore, it is of great significance to develop an electronic mechanical brake system with high safety performance, fast response speed, low energy consumption and small size to promote the rapid industrialization application of the electronic mechanical brake system. SUMMARY

[0007] In order to overcome the deficiencies of the prior art, the present application provides a tooth disc type electronic mechanical parking mechanism and a tooth disc type electronic mechanical parking mechanism life prediction method.

[0008] In order to achieve the various purposes of the present application, the present application adopts the following technical solutions:

[0009] A tooth disc type electronic mechanical parking mechanism is proposed to adapt to one of the purposes of the present application, which comprises a static disc arranged on the main shaft of an EMB driving motor and a locking mechanism for locking the static disc, wherein,

[0010] The static disc is fixedly connected to the main shaft of the EMB driving motor;

[0011] The locking mechanism comprises a dynamic disc and a linear driving mechanism for driving the dynamic disc to move linearly, wherein,

[0012] The dynamic disc and the static disc are provided with a ratchet structure therebetween;

[0013] The straight line driving mechanism comprises a helical gear and a rotary driving mechanism for driving the helical gear to rotate; the helical gear, the moving disc and the static disc are coaxially arranged; the moving disc is fixed on the end face of the helical gear; the helical gear is mounted on the shell of the EMB reducer through a sliding connection structure; the sliding connection structure is used to facilitate the helical gear to move along the axis direction of the main shaft of the EMB driving motor;

[0014] The rotary driving mechanism comprises a brush motor and a worm, wherein the worm is mounted on the main shaft of the brush motor, and the worm is in perpendicular interlaced arrangement engagement with the helical gear.

[0015] Preferably, the end face of the static disc close to the moving disc is a first locking surface; the end face of the moving disc opposite to the first locking surface of the static disc is a second locking surface; the ratchet structure comprises ratchets arranged on the first locking surface and the second locking surface respectively.

[0016] Preferably, the sliding connection structure comprises a plurality of rotation-stopping limiting pin shafts arranged on the helical gear, and the plurality of rotation-stopping limiting pin shafts are uniformly arranged along the circumferential direction of the helical gear; the shell of the EMB reducer is provided with a plurality of limiting holes matched with the rotation-stopping limiting pin shafts.

[0017] Preferably, the main shaft of the EMB driving motor is provided with a transmission gear; the inner cavity of the static disc is provided with a tooth groove matched with the gear teeth of the transmission gear; the static disc is interference fitted on the transmission gear.

[0018] Another object of the present application is to provide a life prediction method of a tooth disc type electronic mechanical parking mechanism, comprising:

[0019] When it is detected that the current parking torque of the tooth disc type electronic mechanical parking mechanism is less than the preset parking torque required by the vehicle, the corresponding number of interlocking teeth of the tooth disc, the tooth disc hardness ratio, the tooth disc clamping force and the tooth disc creep rate are obtained;

[0020] According to the current parking torque and the number of interlocking teeth corresponding to the tooth disc, the torque borne by each ratchet in the tooth disc is determined, and according to the torque borne by each ratchet, the radius of the static disc and the radius of the center hole of the static disc, the shear force borne by each ratchet in the tooth disc is determined.

[0021] According to the radius of the static disc, the radius of the center hole of the static disc and the number of interlocking teeth, the radial cross-sectional area of each ratchet is determined, and according to the shear force borne by each ratchet and the radial cross-sectional area of each ratchet, the shear strength borne by each ratchet is determined.

[0022] The characteristic data set constructed by the torque borne by each ratchet, the shear force borne by each ratchet, the radial cross-sectional area of each ratchet, the shear strength borne by each ratchet, the hardness ratio of the dog plate, the clamping force of the dog plate, and the creep rate of the dog plate is input into the to-be-trained prediction model, and the output error between the wear life prediction value of the dog plate and the actual wear life is calculated.

[0023] If the output error is less than the preset error, the current to-be-trained prediction model is taken as a dog plate wear life prediction model to predict the wear life of the dog plate, and the dog plate wear life prediction of the dog plate type electronic mechanical parking mechanism is completed.

[0024] Optionally, the step of determining the current parking torque of the dog plate type electronic mechanical parking mechanism comprises:

[0025] The parking brake force torque, the parking brake force safety coefficient, the wheel brake radius, and the friction factor of the brake disc of a single wheel edge of the vehicle are obtained.

[0026] A first product between the parking brake force torque of the single wheel edge of the vehicle and the parking brake force safety coefficient is calculated, and a first ratio between the first product and the wheel brake radius is used to determine the brake force of the single wheel edge of the vehicle.

[0027] A second ratio between the brake force of the single wheel edge of the vehicle and the friction factor of the brake disc is used to determine the piston thrust output by the EMB actuator of the single wheel edge, and the current parking torque of the dog plate type electronic mechanical parking mechanism is calculated according to the piston thrust output by the EMB actuator.

[0028] Optionally, the step of determining the torque borne by each ratchet in the dog plate according to the current parking torque of the dog plate type electronic mechanical parking mechanism and the corresponding number of the embedded teeth pairs of the dog plate comprises:

[0029] The current parking torque of the dog plate type electronic mechanical parking mechanism and the corresponding number of the embedded teeth pairs of the dog plate are obtained.

[0030] A third ratio between the current parking torque of the dog plate type electronic mechanical parking mechanism and the corresponding number of the embedded teeth pairs of the dog plate is used to determine the torque borne by each ratchet in the dog plate.

[0031] Optionally, the step of determining the shear force borne by each ratchet in the dog plate according to the torque borne by each ratchet, the radius of the static plate, and the center hole radius of the static plate comprises:

[0032] The torque borne by each ratchet in the dog plate, the radius of the static plate, and the center hole radius of the static plate are obtained.

[0033] calculating a first difference between the radius of the static disc and the radius of the central hole of the static disc, and determining the shear force borne by each ratchet according to a fourth ratio between the torque borne by each ratchet and the first difference.

[0034] Optionally, the step of determining the radial cross-sectional area of each ratchet according to the radius of the static disc, the radius of the central hole of the static disc, and the number of ratchet pairs, and determining the shear strength borne by each ratchet according to the shear force borne by each ratchet and the radial cross-sectional area of each ratchet, comprises:

[0035] obtaining the radius of the static disc, the radius of the central hole of the static disc, the number of ratchet pairs, and the shear force borne by each ratchet;

[0036] calculating a second difference between the first square value of the radius of the static disc and the second square value of the radius of the central hole of the static disc, and calculating a second product between the second difference and the ratio of the circumference of a circle to its diameter;

[0037] calculating a fifth ratio between the second product and twice the number of ratchet pairs to determine the radial cross-sectional area of each ratchet;

[0038] determining the shear strength borne by each ratchet according to a sixth ratio between the shear force borne by each ratchet and the radial cross-sectional area of each ratchet.

[0039] Optionally, the step of training the wear life prediction model of the disc comprises:

[0040] obtaining a feature data set, wherein the feature data set comprises a plurality of feature data samples and their corresponding wear life label values;

[0041] initializing the to-be-trained prediction model, randomly assigning network weight values and biases of the to-be-trained prediction model, and randomly selecting a first feature data sample;

[0042] forwardly calculating the output of each hidden layer and the output of the output layer in the to-be-trained prediction model, and calculating an output error between the output of the output layer and the actual wear life of the disc, wherein the output of the output layer represents a wear life prediction value of the disc;

[0043] if the output error is greater than or equal to a preset error threshold, back-propagating the output error from the output layer to calculate the error of each hidden layer in the to-be-trained prediction model, so as to adjust the weight and bias of each neuron in the to-be-trained prediction model;

[0044] Circulating the above steps until the output error is less than the preset error threshold or a preset number of iterations is reached to complete the training of the die plate wear life prediction model.

[0045] Optionally, the to-be-trained prediction model and the base network architecture of the die plate wear life prediction model are back propagation neural networks; the wear life of the die plate represents the time during which the die plate can still maintain effective function when the wear degree of the die plate reaches a certain critical point; the die plate hardness ratio represents the hardness ratio between the dynamic plate material in the die plate and the static plate material in contact with the dynamic plate material; the die plate clamping force represents the pressure applied between the dynamic plate in the die plate and the static plate in contact with the dynamic plate; and the die plate creep rate represents the proportion of relative sliding between the dynamic plate in the die plate and the static plate in contact with the dynamic plate due to insufficient friction.

[0046] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0047] 1. The die plate type electronic mechanical parking mechanism of the present application arranges a dynamic plate and a static plate on the main shaft of an EMB driving motor; drives the worm to rotate through the motor, thereby pushing the bevel gear and the dynamic plate fixed on the bevel gear to move axially, so as to make the ratchet teeth on the second locking surface of the dynamic plate engage with the ratchet teeth on the first locking surface of the static plate to lock the EMB driving motor, thereby realizing the parking function; compared with the common parking structure, the die plate type electronic mechanical parking mechanism of the present application has a large torque density and a small volume, and is convenient to deploy on an EMB brake actuator.

[0048] 2. The die plate type electronic mechanical parking mechanism of the present application utilizes the reverse motion self-locking function of the vertically staggered and engaged worm and bevel gear; after the torque of the power source (motor) is transmitted to the static plate and the parking is completed by the motor driving the dynamic plate to clamp the static plate, the motor can stop working while still maintaining the parking force; compared with the parking scheme in which most of the existing parking structures use electromagnetic valves and electromagnetic brakes as power sources, the die plate type electronic mechanical parking mechanism of the present application has the advantages of compact structure, low energy consumption, and convenient deployment.

[0049] 3. Since the die plate in the electronic mechanical parking mechanism is subjected to static friction for a long time, each ratchet tooth in the die plate will be worn out, which may cause the parking mechanism to fail, or even cause a safety accident such as a car accident, etc. Therefore, the die plate type electronic mechanical parking mechanism life prediction method of the present application has the following beneficial effects:

[0050] Firstly, the service life prediction method of the tooth disc type electronic mechanical parking mechanism can accurately predict the wear life of the tooth disc by establishing a tooth disc wear life prediction model based on a back propagation neural network (BPNN) and considering multiple important factors such as torque, shear force, radial cross-sectional area, shear strength, tooth disc hardness ratio, clamping force and creep rate of the ratchet. This method provides the ability to predict the degree of wear in advance by real-time monitoring of these key parameters, thereby effectively avoiding failures caused by wear.

[0051] Secondly, the service life prediction method of the tooth disc type electronic mechanical parking mechanism can significantly improve the safety of the tooth disc type electronic mechanical parking mechanism. By predicting the wear life of the tooth disc, measures can be taken before the wear reaches the critical point, avoiding the problem of rolling caused by the failure of the parking mechanism. The safety hazards caused by rolling may lead to serious traffic accidents, and this prediction method can greatly reduce this risk.

[0052] Thirdly, the service life prediction method of the tooth disc type electronic mechanical parking mechanism can greatly reduce maintenance costs. The tooth disc wear life prediction model can monitor the wear state of the tooth disc in real time, thereby helping vehicle operators or owners to discover problems in advance and perform maintenance, avoiding unnecessary frequent inspections and premature replacement, and also avoiding expensive repair costs caused by sudden failure.

[0053] Fourthly, the service life prediction method of the tooth disc type electronic mechanical parking mechanism can greatly improve the reliability and service life of the parking mechanism. By real-time monitoring and prediction of tooth disc wear, the use conditions and maintenance cycle of the parking mechanism can be continuously optimized in actual work. In this way, the overall reliability and service life of the tooth disc type electronic mechanical parking mechanism are improved, thereby reducing the failure rate and maintenance requirements in long-term operation.

[0054] Fifthly, the service life prediction method of the tooth disc type electronic mechanical parking mechanism has significant practical value and can effectively solve the failure and safety problems caused by tooth disc wear in the tooth disc type electronic mechanical parking mechanism, providing important technical support for the safety, economy and intelligent development of intelligent transportation systems. BRIEF DESCRIPTION OF DRAWINGS

[0055] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the following drawings, in which:

[0056] Figure 1 is a structural schematic diagram of the tooth disc type electronic mechanical parking mechanism of the present application;

[0057] Figure 2 is a structural schematic diagram of the bevel gear and the driving disc;

[0058] Figure 3 is a structural schematic diagram of a static disc;

[0059] Figure 4 is a structural schematic diagram of a spring piece;

[0060] Figure 5 is a flowchart of a tooth disc type electromechanical parking mechanism life prediction method in an embodiment of the present application;

[0061] Figure 6 is a flowchart of training a tooth disc wear life prediction model in an embodiment of the present application;

[0062] Figure 7 is a schematic diagram of a calculation process based on a back propagation neural network in an embodiment of the present application;

[0063] Figure 8 is a principle block diagram of a tooth disc wear life prediction device in an embodiment of the present application;

[0064] Figure 9 is a structural schematic diagram of a computer device in an embodiment of the present application.

[0065] In the figure: 1 - static disc; 101 - first locking surface; 2 - moving disc; 201 - second locking surface; 3 - bevel gear; 4 - spring piece; 5 - limit pin; 6 - transmission gear; 7 - worm; 8 - brush motor; 9 - main shaft of EMB driving motor. DETAILED DESCRIPTION

[0066] The embodiments of the present application are described in detail below with reference to the accompanying drawings. The embodiments described below are examples for explaining the present application and should not be construed as limiting the present application.

[0067] It should be understood by those skilled in the art that the singular forms "a," "an," and "the" used in this application include plural references unless specifically stated otherwise. It should be further understood that the use of the term "include" in the specification of the present application means that the features, integers, steps, operations, elements, and / or components described in the specification exist, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there can be an intermediate element. In addition, "connected" or "coupled" used herein can include wireless connection or wireless coupling. The phrase "and / or" used herein includes all or any single unit and all combinations of the associated listed items.

[0068] As those skilled in the art will appreciate, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further appreciated that terms, such as those defined in commonly used dictionaries, should be given their ordinary and customary meaning, unless explicitly defined otherwise herein and unless the context clearly dictates otherwise.

[0069] As those skilled in the art will appreciate, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further appreciated that terms, such as those defined in commonly used dictionaries, should be given their ordinary and customary meaning, unless explicitly defined otherwise herein and unless the context clearly dictates otherwise. As those skilled in the art will appreciate, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further appreciated that terms, such as those defined in commonly used dictionaries, should be given their ordinary and customary meaning, unless explicitly defined otherwise herein and unless the context clearly dictates otherwise. As those skilled in the art will appreciate, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further appreciated that terms, such as those defined in commonly used dictionaries, should be given their ordinary and customary meaning, unless explicitly defined otherwise herein and unless the context clearly dictates otherwise.

[0070] The hardware referred to by the names "server", "client", "service node" and the like in the present application is essentially an electronic device with the equivalent capabilities of a personal computer, and is a hardware device with the necessary components disclosed by the von Neumann principle, including a central processing unit (including an arithmetic unit and a controller), a memory, an input device, and an output device. The computer program is stored in the memory, the central processing unit calls the program stored in the external memory into the memory for running, executes the instructions in the program, and interacts with the input and output devices to complete a specific function.

[0071] It should be noted that the concept of "server" in the present application can also be extended to the case of a server cluster. According to the network deployment principle understood by those skilled in the art, the servers should be logically divided, and in physical space, these servers can be independent of each other but can be called through an interface, or can be integrated into a physical computer or a computer cluster. Those skilled in the art should understand this variation and should not be restricted by the implementation of the network deployment of the present application.

[0072] One or more technical features of the present application, unless explicitly specified, can be deployed on a server to implement access by remotely calling the online service interface provided by the server, or can be directly deployed and run on a client to implement access.

[0073] The neural network model referred to or possibly referred to in the present application, unless explicitly specified, can be deployed on a remote server and remotely called at the client, or can be deployed on a client with sufficient device capability for direct calling. In some embodiments, when it is run on a client, its corresponding intelligence can be obtained through transfer learning to reduce the requirement for client hardware running resources and avoid excessive occupation of client hardware running resources.

[0074] The various data involved in the present application, unless explicitly specified, can be remotely stored on a server or stored on a local terminal device, as long as it is suitable for being called by the technical solutions of the present application.

[0075] Those skilled in the art should know that the various methods of the present application, although based on the same concept and described to present commonality among them, are independently executable unless otherwise specified. Similarly, for each embodiment disclosed in the present application, it is based on the same inventive concept, and therefore, for the same concept of expression, and although the concept of expression is different, it is only for the convenience of appropriately transforming the concept, and should be understood as equivalent.

[0076] The various embodiments to be disclosed in the present application can be combined with each other unless it is explicitly indicated that they are mutually exclusive. The relevant technical features of the various embodiments can be combined flexibly to form new embodiments, as long as such combination does not deviate from the spirit of the present application and can meet the needs of the prior art or solve some deficiencies in the prior art. For this variation, those skilled in the art should know.

[0077] Please refer to Figures 1 to 4 The tooth disc type electronic mechanical parking mechanism of the present application comprises a static disc arranged on the main shaft of an EMB driving motor and a locking mechanism for locking the static disc, wherein,

[0078] The static disc is fixedly connected to the main shaft of the EMB driving motor;

[0079] The locking mechanism comprises a dynamic disc and a linear driving mechanism for driving the dynamic disc to move linearly, wherein,

[0080] The dynamic disc and the static disc are provided with a ratchet structure therebetween;

[0081] The linear driving mechanism comprises a helical gear and a rotary driving mechanism for driving the helical gear to rotate; the helical gear, the dynamic disc and the static disc are coaxially arranged; the dynamic disc is fixed to the end face of the helical gear; the helical gear is mounted on the housing of an EMB reducer through a sliding connection structure; the sliding connection structure is used to facilitate the movement of the helical gear along the axial direction of the main shaft of the EMB driving motor, and the sliding connection structure comprises a plurality of rotation-stopping limiting pin shafts arranged on the helical gear, which are uniformly arranged along the circumferential direction of the helical gear; the housing of the EMB reducer is provided with a plurality of limiting holes matched with the rotation-stopping limiting pin shafts.

[0082] The rotary driving mechanism comprises a brush motor and a worm, wherein the worm is mounted on the main shaft of the brush motor, and the worm and the helical gear are vertically and staggeredly arranged in engagement.

[0083] Please refer to Figures 1 to 4 The end face of the static disc close to the dynamic disc is a first locking surface; the end face of the dynamic disc opposite to the first locking surface of the static disc is a second locking surface; the ratchet structure comprises ratchets arranged on the first locking surface and the second locking surface, respectively.

[0084] Please refer to Figures 1 to 4The sliding connection structure includes multiple sets of anti-rotation limiting pins disposed on the helical gear, and the multiple sets of anti-rotation limiting pins are evenly arranged along the circumferential direction of the helical gear; the housing of the EMB reducer is provided with multiple sets of limiting holes that cooperate with the anti-rotation limiting pins; by setting the anti-rotation limiting pins, the helical gear can be limited and guided, so that the helical gear can only move axially under the drive of the screw helical gear.

[0085] In this embodiment, there are two sets of anti-rotation limiting pins.

[0086] Please see Figures 1 to 4 The main shaft of the EMB drive motor is provided with a transmission gear; the inner cavity of the stationary disc is provided with a tooth groove that meshes with the gear teeth of the transmission gear; the stationary disc is interference-fitted onto the transmission gear, thereby fixing the stationary disc onto the main shaft of the EMB drive motor.

[0087] Please see Figures 1 to 4 The inner cavity of the helical gear is provided with a spring plate. One end of the spring plate is fixed to the housing of the EMB reducer, and the other end extends obliquely into the inner wall of the helical gear. In this embodiment, there are at least two sets of spring plates. By setting multiple sets of spring plates, the axial movement of the helical gear is limited, so that the helical gear can only move axially under the rotation of the worm.

[0088] Please see Figures 1 to 4 The crank-type electromechanical parking mechanism of this application arranges a moving plate and a stationary plate on the main shaft of an EMB drive motor. The end face of the stationary plate near the moving plate is a first locking surface; the end face of the moving plate opposite to the first locking surface of the stationary plate is a second locking surface. The ratchet structure includes ratchet teeth respectively disposed on the first locking surface and the second locking surface. A brushed motor drives a worm gear to rotate, thereby pushing a helical gear and a moving plate fixed on the helical gear to move axially, so as to cause the ratchet teeth on the second locking surface of the moving plate to mesh with the ratchet teeth on the first locking surface of the stationary plate to lock the EMB drive motor, thereby achieving the parking function. In addition, the crank-type electromechanical parking mechanism of this application achieves parking through the meshing of the ratchet teeth on the moving plate and the stationary plate. Compared with the existing common parking structures, the crank-type electromechanical parking mechanism of this application has a high torque density, small size, and is convenient to deploy on an EMB brake actuator.

[0089] The tooth disc type electronic mechanical parking mechanism of the application utilizes the reverse motion self-locking function of the vertically staggered meshing worm and bevel gear, and ingeniously designs a parking power transmission mechanism to transmit the torque of the power source (brush motor) to the driving disc. After the driving disc clamps the static disc to complete parking, the brush motor can stop working while still maintaining the parking force. Compared with the existing parking schemes that use electromagnetic valves and electromagnetic brakes as the power source, the tooth disc type electronic mechanical parking mechanism of the application has the advantages of compact structure, low energy consumption and convenient deployment.

[0090] Please refer to Figure 5 In an embodiment, the tooth disc type electronic mechanical parking mechanism and the service life prediction method thereof of the application comprise:

[0091] In step S10, when it is detected that the current parking torque of the tooth disc type electronic mechanical parking mechanism is less than the preset parking torque required by the vehicle, the number of pairs of meshing teeth corresponding to the tooth disc in the tooth disc type electronic mechanical parking mechanism, the tooth disc hardness ratio, the tooth disc clamping force and the tooth disc creep rate are obtained.

[0092] The tooth disc wear life prediction system in the terminal device can respond to the instruction for predicting the wear life of the tooth disc of the tooth disc type electronic mechanical parking mechanism, and when it is detected that the current parking torque of the tooth disc type electronic mechanical parking mechanism is less than the preset parking torque required by the vehicle, the number of pairs of meshing teeth corresponding to the tooth disc in the tooth disc type electronic mechanical parking mechanism, the tooth disc hardness ratio, the tooth disc clamping force and the tooth disc creep rate are obtained. The preset parking torque required by the vehicle can be the theoretical parking torque of the vehicle. The wear life of the tooth disc represents the time during which the tooth disc can still maintain effective function when the wear degree reaches a certain critical point during use. The tooth disc hardness ratio represents the hardness ratio between the material of the driving disc and the material of the static disc in contact with the driving disc. The tooth disc clamping force represents the pressure applied between the driving disc and the static disc in contact with the driving disc. The tooth disc creep rate represents the proportion of relative sliding between the driving disc and the static disc in contact with the driving disc due to insufficient friction.

[0093] In some embodiments, the step of determining the current parking torque of the tooth disc type electronic mechanical parking mechanism comprises:

[0094] In step S101, the parking brake torque of a single wheel edge of the vehicle, the parking brake force safety coefficient, the wheel brake radius and the friction coefficient of the brake disc are obtained.

[0095] In step S103, the first product of the parking brake torque of the single wheel edge of the vehicle and the parking brake force safety coefficient is calculated, and the braking force of the single wheel edge of the vehicle is determined according to the first ratio between the first product and the wheel brake radius.

[0096] Step S105, determining the piston thrust of the EMB actuator output of the single wheel edge according to the second ratio between the braking force of the single wheel edge of the vehicle and the friction factor of the brake disc, and calculating the current parking torque of the tooth disc type electronic mechanical parking mechanism according to the piston thrust of the EMB actuator output.

[0097] Specifically, first, the parking braking force torque of the single wheel edge of the vehicle, the parking braking force safety factor, the wheel braking radius and the friction factor of the brake disc are obtained, the parking braking force torque N of the single wheel edge of the vehicle is calculated through vehicle information; then, the braking force F of the single wheel edge of the vehicle during parking is calculated by formula (1) through the parking braking force torque N of the single wheel edge of the vehicle and the wheel braking radius b. b , which is expressed as:

[0098]

[0099] Wherein, σ represents the parking braking force safety factor, σ>1, and the value range is [1.2, 1.5];

[0100] Then, the piston thrust F of the EMB actuator output of the single wheel edge during parking can be calculated according to formula (2) through the braking force F of the single wheel edge of the vehicle and the friction factor μ1 of the brake disc. b

[0101]

[0102] Finally, the current parking torque N required to be provided by the main shaft of the EMB driving motor is calculated through the calculated piston thrust F of the EMB actuator output of the single wheel edge during parking and EMB related parameters, and the torque is the current parking force of the tooth disc type electronic mechanical parking mechanism, wherein the EMB related parameters include reducer reduction ratio and motion conversion mechanism parameters, etc., and the motion conversion mechanism includes but is not limited to screw rod, force amplification mechanism and their combination.

[0103] Step S20, determining the torque borne by each ratchet in the tooth disc according to the current parking torque and the corresponding number of tooth pairs of the tooth disc, and determining the shear force borne by each ratchet in the tooth disc according to the torque borne by each ratchet, the radius of the static disc and the center hole radius of the static disc.

[0104] ​When the current parking torque of the crank-type electromechanical parking mechanism is detected to be less than the preset parking torque required by the vehicle, the following steps are taken: after obtaining the number of interlocking tooth pairs, the hardness ratio, the clamping force, and the creep rate of the crank-type electromechanical parking mechanism, the torque borne by each ratchet in the crank is determined based on the current parking torque and the number of interlocking tooth pairs. Based on the torque borne by each ratchet, the radius of the stationary disc, and the radius of the center hole of the stationary disc, the shear force borne by each ratchet in the crank is determined.

[0105] In some embodiments, the step of determining the torque borne by each ratchet tooth in the crankset based on the current parking torque and the number of interlocking tooth pairs corresponding to the crankset includes:

[0106] Step S201: Obtain the current parking torque of the crank-type electromechanical parking mechanism and the number of corresponding interlocking teeth of the crank;

[0107] Step S203: Determine the torque borne by each ratchet in the crankshaft based on the third ratio between the current parking torque of the crankshaft electromechanical parking mechanism and the number of corresponding interlocking tooth pairs.

[0108] The crankcase wear life prediction system in the terminal device can obtain the current parking torque N of the crankcase electromechanical parking mechanism and the corresponding number of interlocking tooth pairs C of the crankcase; based on a third ratio between the current parking torque N of the crankcase electromechanical parking mechanism and the corresponding number of interlocking tooth pairs C of the crankcase, the torque N borne by each ratchet in the crankcase is determined. C Wherein, the torque N borne by each ratchet tooth in the toothed disc C The expression is:

[0109]

[0110] Wherein, the N C N represents the torque borne by each ratchet tooth in the crankset, N represents the current parking torque of the crankset electromechanical parking mechanism, and C represents the number of corresponding interlocking tooth pairs in the crankset.

[0111] In a further embodiment, the step of determining the shear force borne by each ratchet tooth in the toothed disc based on the torque borne by each ratchet tooth, the radius of the stationary disc, and the radius of the center hole of the stationary disc includes:

[0112] Step S2001: Obtain the torque borne by each ratchet tooth in the toothed disc, the radius of the stationary disc, and the radius of the center hole of the stationary disc;

[0113] Step S2003, calculating a first difference between the radius of the static disc and the radius of the central hole of the static disc, and determining the shear force borne by each ratchet of the disc according to a fourth ratio between the torque borne by each ratchet and the first difference.

[0114] After determining the torque borne by each ratchet of the disc, the torque N borne by each ratchet of the disc is obtained C , the radius R of the static disc and the radius r of the central hole of the static disc; a first difference between the radius R of the static disc and the radius r of the central hole of the static disc is calculated, and the shear force F borne by each ratchet of the disc is determined according to a fourth ratio between the torque N borne by each ratchet and the first difference. C C ; wherein the expression of the shear force F borne by each ratchet of the disc is: C

[0115]

[0116] wherein F C represents the shear force borne by each ratchet of the disc, N C represents the torque borne by each ratchet of the disc, R represents the radius of the static disc, and r represents the radius of the central hole of the static disc.

[0117] Step S30, determining the radial cross-sectional area of each ratchet according to the radius of the static disc, the radius of the central hole of the static disc and the number of the corresponding ratchet pairs, and determining the shear strength borne by each ratchet according to the shear force borne by each ratchet and the radial cross-sectional area of each ratchet.

[0118] After determining the torque borne by each ratchet of the disc according to the current parking torque and the number of the corresponding ratchet pairs of the disc, and determining the shear force borne by each ratchet of the disc according to the torque borne by each ratchet, the radius of the static disc and the radius of the central hole of the static disc, the radial cross-sectional area of each ratchet is determined according to the radius of the static disc, the radius of the central hole of the static disc and the number of the corresponding ratchet pairs, and the shear strength borne by each ratchet is determined according to the shear force borne by each ratchet and the radial cross-sectional area of each ratchet.

[0119] In some embodiments, the step of determining the radial cross-sectional area of each ratchet according to the radius of the static disc, the radius of the central hole of the static disc and the number of the corresponding ratchet pairs, and determining the shear strength borne by each ratchet according to the shear force borne by each ratchet and the radial cross-sectional area of each ratchet, comprises:

[0120] ​​Step S301, obtaining the radius of the static disc, the center hole radius of the static disc, the logarithm of the relative embedded teeth, and the shear force borne by each ratchet tooth;

[0121] Step S303, calculating a second difference value between the first square value of the radius of the static disc and the second square value of the center hole radius of the static disc, and calculating a second product between the second difference value and the circular constant;

[0122] Step S305, calculating a fifth ratio value between the second product and twice the logarithm of the relative embedded teeth to determine the radial cross-sectional area of each ratchet tooth;

[0123] Step S307, determining the shear strength borne by each ratchet tooth according to a sixth ratio value between the shear force borne by each ratchet tooth and the radial cross-sectional area of each ratchet tooth.

[0124] The tooth disc wear life prediction system in the terminal device can obtain the radius R of the static disc, the center hole radius r of the static disc, the logarithm C of the relative embedded teeth, and the shear force F borne by each ratchet tooth C ; calculating a second difference value between the first square value of the radius R of the static disc and the second square value of the center hole radius r of the static disc, and calculating a second product between the second difference value and the circular constant π; calculating a fifth ratio value between the second product and twice the logarithm of the relative embedded teeth to determine the radial cross-sectional area S of each ratchet tooth; wherein the expression of the radial cross-sectional area S of each ratchet tooth is:

[0125]

[0126] Wherein S represents the radial cross-sectional area of each ratchet tooth, C represents the logarithm of the relative embedded teeth, R represents the radius of the static disc, r represents the center hole radius of the static disc, and π represents the circular constant.

[0127] Further, after determining the radial cross-sectional area S of each ratchet tooth, the shear strength τ1 borne by each ratchet tooth is determined according to a sixth ratio value between the shear force F C borne by each ratchet tooth and the radial cross-sectional area S of each ratchet tooth, wherein the shear strength τ1 borne by each ratchet tooth is represented as:

[0128]

[0129] Wherein F C represents the shear force borne by each ratchet tooth, S represents the radial cross-sectional area of each ratchet tooth, and τ1 represents the shear strength borne by each ratchet tooth.

[0130] A safety constraint is applied to the shear strength τ1 borne by each ratchet tooth, that is:

[0131] τ1≤Kτ allow (7)

[0132] wherein, τ allow represents the allowable shear strength of the material of the moving disc and the static disc, K represents a safety factor, and K < 1;

[0133] In some embodiments, a minimum static disc radius calculation model can be constructed according to the torque N C , the number of teeth C, the allowable shear strength τ allow (τ a ) of the material of the moving disc and the static disc, the safety factor K, the radius R of the static disc, and the radius r of the central hole of the static disc, which is represented as:

[0134]

[0135] wherein, R represents the radius of the static disc, r represents the radius of the central hole of the static disc (determined by the motor shaft), C represents the number of teeth, K represents the safety factor, τ a represents the allowable shear strength of the material of the moving disc and the static disc, and N C represents the torque borne by each ratchet tooth.

[0136] The minimum static disc radius R is obtained by solving the minimum static disc radius calculation model constructed above under the premise of meeting the safety constraint.

[0137] Step S40, the feature data set constructed by the torque borne by each ratchet tooth, the shear force borne by each ratchet tooth, the radial cross-sectional area of each ratchet tooth, the shear strength borne by each ratchet tooth, the hardness ratio of the tooth disc, the clamping force of the tooth disc, and the creep rate of the tooth disc is input into the to-be-trained prediction model, and the output error between the wear life prediction value of the tooth disc and the actual wear life is calculated;

[0138] Step S50, if the output error is less than the preset error, the current to-be-trained prediction model is taken as a tooth disc wear life prediction model to predict the wear life of the tooth disc, and the tooth disc wear life prediction of the tooth disc type electronic mechanical parking mechanism is completed.

[0139] After the torque borne by each ratchet, the shear force borne by each ratchet, the radial cross-sectional area of each ratchet, and the shear strength borne by each ratchet are calculated, a feature data set composed of the torque borne by each ratchet, the shear force borne by each ratchet, the radial cross-sectional area of each ratchet, the shear strength borne by each ratchet, the hardness ratio of the dog plate, the clamping force of the dog plate, and the creep rate of the dog plate is input into the to-be-trained prediction model, and an output error between the wear life prediction value of the dog plate and the actual wear life is calculated; if the output error is less than the preset error, the current to-be-trained prediction model is taken as a dog plate wear life prediction model to predict the wear life of the dog plate, and the wear life prediction of the dog plate of the electronic mechanical parking mechanism is completed, wherein the basic network architecture of the to-be-trained prediction model and the dog plate wear life prediction model is a back propagation neural network.

[0140] In some embodiments, referring to Figure 6 , the step of training the dog plate wear life prediction model comprises:

[0141] Step S501, acquiring a feature data set, wherein the feature data set comprises a plurality of feature data samples and corresponding wear life label values;

[0142] Step S503, initializing the to-be-trained prediction model, randomly assigning network weight values and biases of the to-be-trained prediction model, and randomly selecting a first feature data sample;

[0143] Step S505, forward calculation to obtain the output of each hidden layer in the to-be-trained prediction model and the output of the output layer, and calculating the output error between the output of the output layer and the actual wear life of the dog plate, wherein the output of the output layer represents the wear life prediction value of the dog plate;

[0144] Step S507, if the output error is greater than or equal to a preset error threshold, the output error is back propagated from the output layer to calculate the error of each hidden layer in the to-be-trained prediction model, so as to adjust the weight and bias of each neuron in the to-be-trained prediction model;

[0145] Step S509, repeating the above steps until the output error is less than the preset error threshold or a preset iteration number is reached, to complete the training of the dog plate wear life prediction model.

[0146] Specifically, according to the design parameters and material requirements, the parking mechanism sample is made, and is deployed to the EMB actuator terminal, and then the bench simulation real vehicle parking working condition is simulated, and the parking under various conditions such as parking, unparking and temporary parking is collected in stages and working conditions, according to the torque borne by each ratchet, the shear force borne by each ratchet, the radial cross-sectional area of each ratchet, the shear strength borne by each ratchet, various different hardness ratios of the tooth disc, the use of different tooth disc clamping forces, different motor speeds, tooth disc creep rates, different working temperatures, different working periods and other single or multiple variables, and according to the real vehicle working condition, reasonable bench test working condition spectrum is set, and then the tooth disc and other related information, working condition information and wear results are collected strictly according to the test plan. In order to meet the model of real vehicle deployment application, the tooth disc material parameters are used as compensation information, which can be used as design vehicle information input, and the working condition and environmental parameters are used as the main input information, which can be obtained and recorded in real time through the related sensors of the real vehicle.

[0147] Further, after completing the signal data collection, first, the data sets collected in different stages and under different working conditions are preprocessed, Gaussian filtering is used to filter the collected load, temperature, speed, friction, working period, vibration signals respectively, to remove the noise in the sensor signal and reduce the influence of noise on the model training accuracy. Then, the data is normalized to make the data range of each feature signal consistent, so as to avoid the influence of the too large numerical range of some features on the model training.

[0148] Further, since the double-tooth disc clamping wear test working condition of the parking mechanism is complex, in order to overcome the problem of limited data quantity and improve the robustness and generalization ability of the model after training, the application adopts a generative adversarial network (Generative Adversarial Networks, GAN) to enhance the collected data. The GAN is composed of a generator and a discriminator, through the adversarial training between the two, the generator can learn the distribution characteristics of the original data and generate new samples similar to the real data. This data enhancement method can effectively expand the data quantity of wear and parameter information, while maintaining the diversity and authenticity of the data.

[0149] Further, the application proposes to use a back propagation neural network (BPNN) as the tooth disc wear life prediction model. The torque borne by each ratchet tooth, the shear force borne by each ratchet tooth, the radial cross-sectional area of each ratchet tooth, the shear strength borne by each ratchet tooth, various different tooth disc hardness ratios, different tooth disc clamping forces, different motor speeds, tooth disc creep rates, different working temperatures, and other data are used to train the back propagation neural network to predict the wear life of the tooth disc of the electronic mechanical parking mechanism. In the back propagation neural network (BPNN), the neurons of the back propagation neural network (BPNN) are connected to each other through weights, signals are propagated forward between the layers of the network, and errors are adjusted through a back propagation mechanism to adjust the weights to optimize the performance of the model.

[0150] Subsequently, please refer to Figure 7 , Figure 7 The detailed calculation process based on the back propagation neural network (BPNN) is shown. The network consists of three layers, namely the input layer, the hidden layer, and the output layer. The input layer and the hidden layer each contain three neurons, each corresponding to a calculation unit. The input layer contains three input nodes (x (t-n) ,x (t-2) ,x (t-1) ) and a bias node (represented by a circle marked with "+1"), and the connections between the layers are represented by a weight matrix w, which is used to map the neurons of the current layer to the next layer to ensure the propagation and calculation of information in the network.

[0151] For the back propagation neural network (BPNN), the entire calculation process is as follows:

[0152] First, the input x is linearly combined with the weight matrix W and the bias term b to form the input of the hidden layer (Hidden Layer), i.e., Wx+b. Subsequently, the input is processed by a nonlinear activation function f(x) to generate the outputs a1, a2, and a3 of the hidden layer; then, the outputs are combined with the corresponding weights and bias terms as the input of the output layer (Output Layer) and are processed by the activation function again to finally generate the output results of the network. Equation (9) shows the mathematical relationship from the input layer to the hidden layer, which is represented as:

[0153]

[0154] where y m represents the input of the input layer, yt denotes the prediction value of point t, μ jm denotes the network weight of the output layer, μ j denotes the threshold value of the hidden layer, n denotes the number of nodes of the input layer, f l denotes the activation function of the hidden layer.

[0155] Formula (10) shows the mathematical relationship from the hidden layer to the output layer, which is represented as:

[0156]

[0157] wherein y denotes the input of the hidden layer, y t denotes the prediction value of point t; λ om denotes the network weight of the hidden layer, λ o denotes the threshold value of the output layer, l denotes the number of nodes of the hidden layer, f o denotes the activation function of the output layer, generally, the logistic function and the hyperbolic function are usually used as the activation function f l of the hidden layer o .

[0158] Further, in order to evaluate the prediction performance of the model, the root mean square error (RMSE), the least mean square error (LE), the mean absolute error (MAE) and the determination coefficient (R 2 ) are proposed in the present application. Among them, RMSE is used to reflect the overall error level between the predicted value and the true value of the model, which can highlight the influence of large errors; MAE as an intuitive indicator can quickly understand the average error level of the model; R 2 measures the goodness of fit of the model to the data. The smaller the RMSE and MAE values of the model, the larger the R 2 value, the more suitable the model is for predicting the wear life of the disc of the disc type electronic mechanical parking mechanism.

[0159]

[0160] wherein y m is the true value of the data sample, is the average value of the true value, y' m is the predicted value.

[0161] The trained model can be deployed to edge devices for local inference to reduce latency. At the same time, new data needs to be collected regularly and the model needs to be retrained to ensure that the prediction accuracy is continuously improved.

[0162] After the above steps, the disc wear life prediction model can be used to predict the wear life of the disc of the disc type electronic mechanical parking mechanism after the disc wear life prediction model is trained to a converged state.

[0163] As can be seen from the above embodiments, compared with the prior art, this application addresses the problem that in the prior art, after prolonged static friction, each ratchet tooth in the crank-type electromechanical parking mechanism will wear down, leading to parking mechanism failure or even serious accidents such as vehicle rollover and injury. This application has, but is not limited to, the following beneficial effects:

[0164] Firstly, this application establishes a toothed disc wear life prediction model based on backpropagation neural network (BPNN) and considers several important factors, such as the torque, shear force, radial cross-sectional area, shear strength, toothed disc hardness ratio, clamping force, and creep rate borne by the ratchet, which can accurately predict the wear life of the toothed disc. This method provides the system with the ability to predict the degree of wear in advance by monitoring these key parameters in real time, thereby effectively avoiding failures caused by wear.

[0165] Secondly, this application can significantly improve the safety of the crank-type electromechanical parking mechanism based on the crank-type. By predicting the wear life of the crank-type, measures can be taken before the wear reaches the critical point, avoiding the problem of vehicle slippage caused by parking mechanism failure. The safety hazards caused by vehicle slippage may lead to serious traffic accidents, and this prediction method can greatly reduce this risk.

[0166] Third, this application can greatly reduce maintenance costs. The crankcase wear life prediction model of this application can monitor the wear status of the crankcase in real time, thereby helping vehicle operators or owners to discover problems in advance and carry out maintenance, avoiding unnecessary frequent inspections and premature replacements, as well as avoiding expensive maintenance costs caused by sudden failures.

[0167] Fourth, this application can significantly improve the reliability and lifespan of the parking mechanism. By monitoring and predicting the wear of the crankshaft in real time, the operating conditions and maintenance cycles of the parking mechanism can be continuously optimized in actual operation. In this way, the overall reliability and service life of the crankshaft-type electromechanical parking mechanism are improved, thereby reducing the failure rate and maintenance requirements during long-term operation.

[0168] In summary, the life prediction method for the gear-type electromechanical parking mechanism proposed in this application has significant practical value. It can effectively solve the failure and safety problems caused by gear wear in the gear-type electromechanical parking mechanism, and provide important technical support for the safety, economy and intelligent development of intelligent transportation systems.

[0169] Please see Figure 8, a toothed disc wear life prediction device in a toothed disc type electromechanical parking mechanism provided for adapting to one of the purposes of the present application, comprising a wear life prediction trigger module 1100, a shear force determination module 1200, a shear strength determination module 1300, an output error determination module 1400, and a wear life prediction module 1500. Wherein the wear life prediction trigger module 1100 is configured to detect that the current parking torque of the toothed disc type electromechanical parking mechanism is less than the preset parking torque required by the vehicle, and obtain the corresponding number of tooth pairs, the tooth hardness ratio, the tooth clamping force and the tooth creep rate of the toothed disc in the toothed disc type electromechanical parking mechanism; the shear force determination module 1200 is configured to determine the torque borne by each ratchet tooth in the toothed disc according to the current parking torque and the corresponding number of tooth pairs of the toothed disc, and determine the shear force borne by each ratchet tooth in the toothed disc according to the torque borne by each ratchet tooth, the radius of the static disc and the center hole radius of the static disc; the shear strength determination module 1300 is configured to determine the radial cross-sectional area of each ratchet tooth according to the radius of the static disc, the center hole radius of the static disc and the number of tooth pairs, and determine the shear strength borne by each ratchet tooth according to the shear force borne by each ratchet tooth and the radial cross-sectional area of each ratchet tooth; the output error determination module 1400 is configured to input the feature data set constructed by the torque borne by each ratchet tooth, the shear force borne by each ratchet tooth, the radial cross-sectional area of each ratchet tooth, the shear strength borne by each ratchet tooth, the tooth hardness ratio, the tooth clamping force and the tooth creep rate into the to-be-trained prediction model, and calculate the output error between the wear life prediction value of the toothed disc and the actual wear life; the wear life prediction module 1500 is configured to, if the output error is less than the preset error, take the current to-be-trained prediction model as the toothed disc wear life prediction model to predict the wear life of the toothed disc and complete the toothed disc wear life prediction of the toothed disc type electromechanical parking mechanism.

[0170] On the basis of any embodiment of the present application, please refer to Figure 9 Another embodiment of the present application further provides an electronic device, which can be realized by a computer device, such as Figure 9As shown, the internal structure diagram of the computer device is shown. The computer device includes a processor, a computer readable storage medium, a memory and a network interface connected by a system bus. Among them, the computer readable storage medium of the computer device stores an operating system, a database and computer readable instructions, the database can store control information sequence, and the computer readable instructions are executed by the processor to enable the processor to realize a tooth disc type electromechanical parking mechanism life prediction method. The processor of the computer device is used to provide computing and control capability to support the operation of the entire computer device. The memory of the computer device can store computer readable instructions, and the computer readable instructions are executed by the processor to enable the processor to execute the tooth disc type electromechanical parking mechanism life prediction method of the present application. The network interface of the computer device is used to connect and communicate with the terminal. Those skilled in the art can understand, Figure 9 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement.

[0171] The processor in the embodiment is used to execute the specific functions of each module in Figure 8 The memory stores the program codes and various data required for executing the above-mentioned modules. The network interface is used for data transmission between the user terminal or the server. The memory in the embodiment of the present application stores the program codes and data required for executing all modules in the tooth disc wear life prediction device in the tooth disc type electromechanical parking mechanism of the present application, and the server can call the program codes and data of the server to execute the functions of all modules.

[0172] The present application also provides a storage medium storing computer readable instructions, which are executed by one or more processors to enable the one or more processors to execute the steps of the tooth disc type electromechanical parking mechanism life prediction method described in any embodiment of the present application.

[0173] The present application also provides a computer program product including computer programs / instructions, which are executed by one or more processors to implement the steps of the tooth disc type electromechanical parking mechanism life prediction method described in any embodiment of the present application.

[0174] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments of the application can be completed by a computer program instructing relevant hardware, and the computer program can be stored in a computer readable storage medium. When the program is executed, the processes of the above-mentioned embodiments of the methods can be included. The storage medium can be a computer readable storage medium such as a magnetic disc, an optical disc, a read-only memory (ROM), or a random access memory (RAM).

[0175] The above only describes some embodiments of the application. It should be pointed out that those skilled in the art can make some improvements and refinements without departing from the principles of the application, and these improvements and refinements should also be considered as the protection scope of the application.

Claims

1. A method for predicting the lifespan of a crank-type electromechanical parking mechanism, characterized in that, include: When the current parking torque of the chain-type electromechanical parking mechanism is detected to be less than the preset parking torque required by the vehicle, the following parameters are acquired: the number of interlocking tooth pairs, the chain hardness ratio, the chain clamping force, and the chain creep rate of the chain-type electromechanical parking mechanism. The chain includes a stationary chain and a moving chain. The chain-type electromechanical parking mechanism includes a stationary chain mounted on the spindle of the EMB drive motor and a locking mechanism for locking the stationary chain. The stationary chain is fixedly connected to the spindle of the EMB drive motor. The locking mechanism includes a moving chain and a linear drive mechanism for driving the moving chain to perform linear motion. A ratchet structure is provided between the moving chain and the stationary chain. The linear drive mechanism includes a helical gear and a mechanism for driving the helical gear to rotate. A rotary drive mechanism is provided, wherein the helical gear, the moving disk, and the stationary disk are coaxially arranged; the moving disk is fixed to the end face of the helical gear; the helical gear is mounted on the housing of the EMB reducer via a sliding connection structure; the sliding connection structure is used to enable the helical gear to move along the axial direction of the main shaft of the EMB drive motor; the rotary drive mechanism includes a motor and a worm gear, wherein the worm gear is mounted on the main shaft of the motor, and the worm gear and the helical gear are meshed in a perpendicularly staggered arrangement; the end face of the stationary disk near the moving disk is a first locking surface; the end face of the moving disk opposite to the first locking surface of the stationary disk is a second locking surface; the ratchet structure includes ratchet teeth respectively disposed on the first locking surface and the second locking surface; Based on the current parking torque and the corresponding number of interlocking tooth pairs of the crankcase, determine the torque borne by each ratchet in the crankcase. Based on the torque borne by each ratchet, the radius of the stationary disc, and the radius of the center hole of the stationary disc, determine the shear force borne by each ratchet in the crankcase. Based on the radius of the stationary disc, the radius of the center hole of the stationary disc, and the number of interlocking tooth pairs, the radial cross-sectional area of ​​each ratchet tooth is determined. Based on the shear force borne by each ratchet tooth and the radial cross-sectional area of ​​each ratchet tooth, the shear strength borne by each ratchet tooth is determined. The feature dataset constructed using the torque borne by each ratchet, the shear force borne by each ratchet, the radial cross-sectional area of ​​each ratchet, the shear strength borne by each ratchet, the hardness ratio of the toothed disc, the clamping force of the toothed disc, and the creep rate of the toothed disc is input into the prediction model to be trained, and the output error between the predicted wear life of the toothed disc and the actual wear life is calculated. If the output error is less than the preset error, the current prediction model to be trained is used as the crankcase wear life prediction model to predict the wear life of the crankcase and complete the crankcase wear life prediction of the crankcase electromechanical parking mechanism.

2. The method for predicting the lifespan of a crank-type electromechanical parking mechanism according to claim 1, characterized in that, The sliding connection structure includes multiple sets of anti-rotation limiting pins disposed on the helical gear, and the multiple sets of anti-rotation limiting pins are evenly arranged along the circumferential direction of the helical gear; the housing of the EMB reducer is provided with multiple sets of limiting holes that cooperate with the anti-rotation limiting pins.

3. The method for predicting the lifespan of a crank-type electromechanical parking mechanism according to claim 1, characterized in that, The steps for determining the current parking torque of a chain-type electromechanical parking mechanism include: Obtain the parking braking torque, parking braking safety factor, wheel braking radius, and brake disc friction coefficient of a single wheel of the vehicle; The first product between the parking braking torque of a single wheel of the vehicle and the parking braking force safety factor is calculated, and the braking force of a single wheel of the vehicle is determined based on the first product and the first ratio between the first product and the wheel braking radius. The piston thrust output by the EMB actuator on a single wheel is determined based on a second ratio between the braking force on a single wheel and the friction coefficient of the brake disc. The current parking torque of the chain-type electromechanical parking mechanism is then calculated based on the piston thrust output by the EMB actuator.

4. The method for predicting the lifespan of a crank-type electromechanical parking mechanism according to claim 1, characterized in that, The step of determining the torque borne by each ratchet tooth in the crankset based on the current parking torque and the corresponding number of interlocking tooth pairs includes: Obtain the current parking torque of the crank-type electromechanical parking mechanism and the number of corresponding interlocking tooth pairs of the crank; The torque borne by each ratchet in the crankcase is determined based on a third ratio between the current parking torque of the crankcase electromechanical parking mechanism and the number of corresponding interlocking tooth pairs.

5. The method for predicting the lifespan of a crank-type electromechanical parking mechanism according to claim 1, characterized in that, The step of determining the shear force borne by each ratchet tooth in the toothed disc based on the torque borne by each ratchet tooth, the radius of the stationary disc, and the radius of the center hole of the stationary disc includes: Obtain the torque borne by each ratchet tooth in the toothed disc, the radius of the stationary disc, and the radius of the center hole of the stationary disc; A first difference between the radius of the stationary disc and the radius of the center hole of the stationary disc is calculated, and a fourth ratio between the torque borne by each ratchet and the first difference is used to determine the shear force borne by each ratchet in the toothed disc.

6. The method for predicting the lifespan of a crank-type electromechanical parking mechanism according to claim 1, characterized in that, The steps of determining the radial cross-sectional area of ​​each ratchet tooth based on the radius of the stationary disc, the radius of the center hole of the stationary disc, and the number of interlocking tooth pairs, and determining the shear strength of each ratchet tooth based on the shear force borne by each ratchet tooth and the radial cross-sectional area of ​​each ratchet tooth, include: Obtain the radius of the stationary disc, the radius of the center hole of the stationary disc, the number of interlocking tooth pairs, and the shear force borne by each ratchet tooth; Calculate and determine a second difference between the first squared value of the radius of the stationary disk and the second squared value of the radius of the center hole of the stationary disk, and calculate and determine a second product between the second difference and pi; Calculate and determine a fifth ratio between the second product and twice the number of interlocking tooth pairs to determine the radial cross-sectional area of ​​each ratchet; The shear strength of each ratchet is determined based on a sixth ratio between the shear force borne by each ratchet and the radial cross-sectional area of ​​each ratchet.

7. The method for predicting the lifespan of a crank-type electromechanical parking mechanism according to claim 1, characterized in that, The steps for training the wear life prediction model of the dental disc include: Obtain a feature dataset, wherein the feature dataset includes multiple feature data samples and their corresponding wear life label values; Initialize the prediction model to be trained by randomly assigning network weights and biases to the prediction model to be trained, and randomly selecting the first feature data sample. The outputs of each hidden layer and the output layer in the prediction model to be trained are calculated forward. The output error between the output of the output layer and the actual wear life of the dental conduit is calculated and determined. The output of the output layer represents the predicted wear life of the dental conduit. If the output error is greater than or equal to a preset error threshold, the output error is backpropagated from the output layer to calculate and determine the error of each hidden layer in the prediction model to be trained, so as to adjust the weight and bias of each neuron in the prediction model to be trained. Repeat the above steps until the output error is less than the preset error threshold or the preset number of iterations is reached, so as to complete the training of the toothed disc wear life prediction model.

8. The method for predicting the lifespan of a crank-type electromechanical parking mechanism according to claim 7, characterized in that, The basic network architecture of the prediction model to be trained and the toothed disc wear life prediction model is a backpropagation neural network. The wear life of the toothbrush represents the time during which the toothbrush can still maintain its effective function when its wear reaches a certain critical point during use. The toothed disc hardness ratio characterizes the hardness ratio between the moving disc material and the stationary disc material in contact with it in the toothed disc; The clamping force of the toothed disc represents the pressure exerted between the moving disc and the stationary disc in contact with it in the toothed disc; The toothed disc creep rate characterizes the relative sliding ratio between the moving disc and the stationary disc in contact with it due to insufficient friction.

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