Chain wheel type electronic mechanical parking mechanism and service life prediction method thereof

Abstract

The invention relates to a crankset type electronic mechanical parking mechanism and a service life prediction method thereof. The crankset type electronic mechanical parking mechanism comprises a static disc and a locking mechanism. The locking mechanism comprises a movable disc and a linear driving mechanism; a ratchet structure is arranged between the movable disc and the static disc; the linear driving mechanism comprises a helical gear and a rotary driving mechanism; the movable disc is fixed to the end face of the bevel gear. The bevel gear is installed on a shell of the EMB speed reducer through a sliding connection structure. The rotary driving mechanism comprises a motor and a worm; the worm is mounted on a main shaft of the motor; and the worm and the helical gear are vertically meshed in a staggered manner. According to the crankset type electronic mechanical parking mechanism, the worm and the bevel gear which are arranged in the staggered mode have the reverse self-locking function, the motor does not need to be continuously powered on after parking is completed, and the crankset type electronic mechanical parking mechanism has the advantages of being compact in structure, low in energy consumption and convenient to deploy.

Description

Technical Field

[0001] The present application relates to the field of vehicle control technology, and in particular to a crankset-type electronic mechanical parking mechanism and a life prediction method for the crankset-type electronic mechanical parking mechanism. Background Art

[0002] Drive-by-wire chassis are crucial for the implementation of advanced autonomous driving technology, and the brake-by-wire system is its most critical component. Electromechanical brakes (EMB) offer advantages such as zero lag, fast response, high control precision, and easy maintenance, making them the mainstream of future automotive drive-by-wire systems. EMB completely eliminates hydraulic and pneumatic pressure-building devices, achieving true brake-by-wire control.

[0003] Traditional automobile parking mechanisms include mechanical zipper type and electronic mechanical parking system (Electronic Parking Brake, EPB). These parking mechanisms require complex mechanical structures and pressure lines (pneumatic or hydraulic) to achieve parking. However, it is imperative to deploy a parking mechanism on the EMB system to achieve the parking function. As far as we know, EMB actuators usually use ball screws, force amplification mechanisms or trapezoidal screws alone or in combination as motion conversion mechanisms to convert the rotational motion of the reducer into translational motion, thereby pushing the brake pads for braking. It is worth noting that no matter which of the above-mentioned motion conversion mechanisms is used, it does not have a self-locking function. Therefore, the parking mechanism is an important component of the EMB.

[0004] Currently, researchers have proposed many excellent parking mechanisms that can be deployed in EMB actuators. Among them, the mainstream parking mechanisms include ratchet and pawl parking mechanisms, disc friction parking mechanisms and electromagnetic clutch types. For example, the invention patent applications with application publication number CN115817440 A and application publication number CN 117227688 A use a ratchet and pawl combined with an electromagnetic valve to achieve parking; the utility model patent with authorization publication number CN 221610450U uses a friction disc to achieve parking; the invention patent application with application publication number CN 115853935A uses an electromagnetic clutch sleeve on the drive shaft of the EMB motor, and clamps the drive shaft of the EMB motor by energizing the electromagnetic clutch, thereby achieving parking through friction.

[0005] However, the mainstream parking mechanisms proposed above have significant shortcomings. For example, ratchet and pawl parking mechanisms require a solenoid valve to push the pawl into the ratchet groove during parking. This requires ensuring the pawl is accurately engaged with the ratchet groove to meet the required parking force, which increases control complexity. Friction disc parking mechanisms typically feature a pattern on the friction pair to increase friction. However, after prolonged static friction, the pattern wears away, potentially causing the parking mechanism to fail at best or, in worse cases, leading to accidents such as the vehicle rolling away and injuring people. The shortcomings of the electromagnetic clutch parking mechanism are as follows: on the one hand, the power density of the electromagnetic clutch is low, and to achieve the parking braking torque, the volume of the electromagnetic clutch will become very large, which makes deployment difficult and does not meet the application requirements of the wire-controlled intelligent chassis. In addition, the electromagnetic brake needs to be continuously energized to keep it loose under driving braking conditions, so it cannot meet the design standard of low energy consumption; on the other hand, during the braking process, the electromagnetic brake needs to be energized to loosen it first, and the EMB actuator is braking at the same time. The entire control process is extremely complex, and this places high demands on the response time and life of the electromagnetic brake.

[0006] In summary, mainstream parking mechanisms still have many problems that need to be solved. Therefore, developing an electromechanical braking system with high safety performance, fast response speed, low energy consumption, and small size is of great significance to promoting the rapid industrialization and application of electromechanical braking systems. Summary of the Invention

[0007] In order to overcome the deficiencies in the prior art, the present application provides a crankset-type electronic mechanical parking mechanism and a method for predicting the life of the crankset-type electronic mechanical parking mechanism.

[0008] In order to meet the various objectives of this application, this application adopts the following technical solutions:

[0009] A toothed disc type electromechanical parking mechanism proposed to meet one of the purposes of this application includes a stator disc arranged on the main shaft of the EMB drive motor and a locking mechanism for locking the stator disc, wherein:

[0010] The stator is fixedly connected to the main shaft of the EMB drive motor;

[0011] The locking mechanism includes a movable disk and a linear drive mechanism for driving the movable disk to perform linear motion, wherein:

[0012] A ratchet structure is provided between the moving disc and the static disc;

[0013] The linear drive mechanism includes a helical gear and a rotary drive mechanism for driving the helical gear to rotate; the helical gear, the movable plate, and the static plate are coaxially arranged; the movable plate 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 axis of the main shaft of the EMB drive motor;

[0014] The rotary drive mechanism includes a brush motor and a worm, wherein the worm is mounted on a main shaft of the brush motor, and the worm is meshed with the helical gear in a vertically staggered arrangement.

[0015] Preferably, the end surface of the static plate close to the dynamic plate is the first locking surface; the end surface of the dynamic plate opposite to the first locking surface of the static plate is the second locking surface; and the ratchet structure includes ratchets respectively arranged on the first locking surface and the second locking surface.

[0016] Preferably, the sliding connection structure includes multiple groups of stop-rotation limit pins arranged on the helical gear, and the multiple groups of stop-rotation limit pins are evenly arranged along the circumferential direction of the helical gear; the housing of the EMB reducer is provided with multiple groups of limit holes that cooperate with the stop-rotation limit pins.

[0017] Preferably, a transmission gear is provided on the main shaft of the EMB drive motor; the inner cavity of the stator is provided with tooth grooves that cooperate with the gear teeth of the transmission gear; and the stator is interference-mounted on the transmission gear.

[0018] A method for predicting the life of a crankset-type electronic mechanical parking mechanism provided for another purpose of the present application includes:

[0019] When detecting that a current parking torque of the crankset-type electronic mechanical parking mechanism is less than a preset parking torque required by the vehicle, obtaining the number of tooth pairs of the cranksets in the crankset-type electronic mechanical parking mechanism, the crankset hardness ratio, the crankset clamping force, and the crankset creep rate;

[0020] Determining the torque borne by each ratchet tooth in the crankset based on the current parking torque and the number of teeth corresponding to the crankset, and determining the shear force borne by each ratchet tooth in the crankset based on the torque borne by each ratchet tooth, the radius of the stator plate, and the radius of the center hole of the stator plate;

[0021] Determine the radial cross-sectional area of each ratchet tooth according to the radius of the stator disk, the radius of the center hole of the stator disk, and the number of pairs of teeth; 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;

[0022] A feature data set constructed by 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 chainring hardness ratio, the chainring clamping force, and the chainring creep rate is input into the prediction model to be trained, and an output error between the predicted wear life value and the actual wear life of the chainring is calculated;

[0023] If the output error is less than the preset error, the current prediction model to be trained is used as the chainring wear life prediction model to predict the chainring wear life, thereby completing the chainring wear life prediction of the chainring type electronic mechanical parking mechanism.

[0024] Optionally, the step of determining the current parking torque of the crankset-type electromechanical parking mechanism includes:

[0025] Obtain the parking brake torque, parking brake safety factor, wheel braking radius, and brake disc friction factor of a single wheel side of the vehicle;

[0026] calculating and determining a first product between the parking brake torque of a single wheel side of the vehicle and the parking brake safety factor, and determining the braking force of the single wheel side of the vehicle based on a first ratio between the first product and the wheel braking radius;

[0027] The piston thrust output by the EMB actuator of a single wheel side is determined based on a second ratio between the braking force of a single wheel side of the vehicle and the friction coefficient of the brake disc, and the current parking torque of the crankset-type electronic mechanical parking mechanism is determined based on the piston thrust output by the EMB actuator.

[0028] Optionally, the step of determining the torque borne by each ratchet tooth in the crankset according to the current parking torque and the number of pairs of teeth corresponding to the crankset includes:

[0029] Obtain the current parking torque of the toothed disc type electronic mechanical parking mechanism and the number of tooth pairs corresponding to the toothed disc;

[0030] The torque borne by each ratchet tooth in the crankset is determined according to a third ratio between the current parking torque of the crankset type electronic mechanical parking mechanism and the number of pairs of teeth corresponding to the crankset.

[0031] Optionally, the step of determining the shear force borne by each ratchet tooth in the crankset according to the torque borne by each ratchet tooth, the radius of the stator plate, and the radius of the center hole of the stator plate includes:

[0032] Obtaining the torque borne by each ratchet tooth in the crankset, the radius of the stator disc, and the radius of the center hole of the stator disc;

[0033] A first difference between the radius of the stator plate and the radius of the center hole of the stator plate is calculated and determined, and a shear force borne by each ratchet in the crankset is determined based on 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 tooth according to the radius of the stator disk, the radius of the center hole of the stator disk, and the number of pairs of teeth, and determining 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 includes:

[0035] Obtain the radius of the stator disc, the radius of the center hole of the stator disc, the number of teeth in each pair, and the shear force borne by each ratchet tooth;

[0036] calculating and determining a second difference between a first square value of the radius of the stator disk and a second square value of the radius of the central hole of the stator disk, and calculating and determining a second product between the second difference and pi;

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

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

[0039] Optionally, the step of training the chainring wear life prediction model includes:

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

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

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

[0043] If the output error is greater than or equal to a preset error threshold, backpropagating the output error 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;

[0044] The above steps are repeated 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 chainring wear life prediction model.

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

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

[0047] 1. The sprocket-type electronic mechanical parking mechanism of the present application is achieved by arranging a movable plate and a stationary plate on the main shaft of the EMB drive motor; the motor drives the worm to rotate, thereby pushing the helical gear and the movable plate fixed to the helical gear to make axial movement, so that the ratchet teeth on the second locking surface of the movable plate engage with the ratchet teeth on the first locking surface of the stationary plate to lock the EMB drive motor, thereby achieving the parking function; compared with existing common parking structures, the sprocket-type electronic mechanical parking mechanism of the present application has high torque density and small size, and is conveniently deployed on the EMB brake actuator.

[0048] 2. The sprocket-type electronic mechanical parking mechanism of the present application utilizes the reverse motion self-locking function of the vertically staggered meshing worm and bevel gears; by transmitting the torque of the power source (motor) to the static plate, after the power source (motor) drives the dynamic plate to clamp the static plate to complete parking, the motor can stop working and still maintain the parking force. Compared with most existing parking solutions that use solenoid valves and electromagnetic brakes as power sources, the sprocket-type electronic mechanical parking mechanism of the present application has the advantages of compact structure, low energy consumption and easy deployment.

[0049] 3. Due to the long-term static friction of the sprocket in the electronic mechanical parking mechanism, each ratchet in the sprocket will be worn out, which may cause the parking mechanism to fail at the least, or even cause safety accidents such as the vehicle rolling away and injuring people. Therefore, the life prediction method of the sprocket type electronic mechanical parking mechanism of the present application has the following beneficial effects:

[0050] First, the life prediction method of the chainring-type electronic mechanical parking mechanism of the present application establishes a chainring wear life prediction model based on the back propagation neural network (BPNN), and takes into account multiple important factors, such as the torque, shear force, radial cross-sectional area, shear strength, chainring hardness ratio, clamping force and creep rate borne by the ratchet, etc., to accurately predict the wear life of the chainring. 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.

[0051] Secondly, the life prediction method of the crankset-type electronic mechanical parking mechanism of the present application can significantly improve the safety of the crankset-type electronic mechanical parking mechanism. By predicting the wear life of the crankset, measures can be taken before the wear reaches a critical point, thereby avoiding the problem of the vehicle rolling away due to failure of the parking mechanism. The safety hazard caused by rolling away may lead to serious traffic accidents, and this prediction method can greatly reduce this risk.

[0052] Third, the life prediction method of the chainring-type electronic mechanical parking mechanism of the present application can significantly reduce maintenance costs. The chainring wear life prediction model of the present application can monitor the wear status of the chainring in real time, thereby helping vehicle operators or owners to detect problems in advance and perform repairs, avoiding unnecessary frequent inspections and premature replacements, and also avoiding expensive repair costs caused by sudden failures.

[0053] Fourthly, the lifespan prediction method for the chainring-type electromechanical parking mechanism of this application can significantly improve the reliability and lifespan of the parking mechanism. By real-time monitoring and prediction of chainring wear, the parking mechanism's operating conditions and maintenance cycles can be continuously optimized in practice. This improves the overall reliability and service life of the chainring-type electromechanical parking mechanism of this application, thereby reducing the failure rate and maintenance requirements during long-term operation.

[0054] Fifth: The life prediction method of the sprocket-type electronic mechanical parking mechanism of this application has significant practical value, and can effectively solve the failure and safety problems caused by sprocket wear in the sprocket-type electronic mechanical parking mechanism, and provides important technical guarantees for the safety, economy and intelligent development of intelligent transportation systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

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

[0057] Figure 2 It is a structural diagram of the helical gear and the moving plate;

[0058] Figure 3 It is a structural diagram of the static disk;

[0059] Figure 4 Schematic diagram of the structure of the shrapnel;

[0060] Figure 5 Schematic diagram of the flow of a method for predicting the life of a crankset-type electronic mechanical parking mechanism in an embodiment of the present application;

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

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

[0063] Figure 8 This is a functional block diagram of a device for predicting the wear life of a crankset in an embodiment of the present application;

[0064] Figure 9 Schematic diagram of the structure of the computer device in the embodiment of the present application.

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

[0066] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and are not to be construed as limiting the present application.

[0067] It will be understood by those skilled in the art that, unless expressly stated otherwise, the singular forms "a", "an", "said" and "the" used herein may also include the plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does 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 refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, "connected" or "coupled" as used herein may include wireless connections or wireless couplings. The term "and / or" used herein includes all or any units and all combinations of one or more associated listed items.

[0068] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0069] It will be understood by those skilled in the art that the terms "client," "terminal," and "terminal device" as used herein include both devices that are wireless signal receivers, i.e., devices that only have wireless signal receivers without transmission capabilities, and devices that have receiving and transmitting hardware capable of two-way communication over a two-way communication link. Such devices may include: cellular or other communication devices such as personal computers and tablet computers, which have single-line displays, multi-line displays, or cellular or other communication devices without multi-line displays; PCS (Personal Communications Service), which may combine voice, data processing, fax, and / or data communication capabilities; PDA (Personal Digital Assistant), which may include a radio frequency receiver, a pager, Internet / Intranet access, a web browser, a notepad, a calendar, and / or a GPS (Global Positioning System) receiver; and conventional laptop and / or palmtop computers or other devices, which have and / or include a radio frequency receiver. As used herein, the terms "client," "terminal," or "terminal device" may be portable, transportable, or installed in a vehicle (air, sea, and / or land), or may be adapted and / or configured to operate locally and / or in a distributed manner at any other location on Earth and / or in space. As used herein, the terms "client," "terminal," or "terminal device" may also refer to a communication terminal, an Internet terminal, or a music / video playback terminal, such as a PDA, an MID (Mobile Internet Device), and / or a mobile phone with music / video playback capabilities, or may include a smart TV, a set-top box, or other device.

[0070] The hardware referred to by names such as "server", "client", and "service node" in this application is essentially an electronic device with capabilities equivalent to those of a personal computer. It is a hardware device that has the necessary components revealed by the von Neumann principle, such as a central processing unit (including an arithmetic unit and a controller), a memory, an input device, and an output device. Computer programs are stored in its memory, and the central processing unit loads the program stored in the external memory into the internal memory for execution, executes the instructions in the program, and interacts with the input and output devices to complete specific functions.

[0071] It should be noted that the concept of "server" referred to in this application can also be extended to server clusters. Based on the network deployment principles understood by those skilled in the art, the servers described should be logically divided. In physical space, these servers can be independent of each other but callable through interfaces, or integrated into a single physical computer or a computer cluster. Those skilled in the art should understand this flexibility and should not use it to constrain the implementation of the network deployment method of this application.

[0072] Unless expressly specified, one or more technical features of the present application can be deployed on a server for implementation and accessed by a client through a remote call to obtain an online service interface provided by the server, or can be directly deployed and run on a client for implementation.

[0073] Unless expressly specified otherwise, the neural network models referenced or may be referenced in this application may be deployed on a remote server and remotely called on the client, or may be deployed and directly called on a client with sufficient device capabilities. In some embodiments, when it runs on the client, its corresponding intelligence may be obtained through transfer learning to reduce the requirements for the client's hardware operating resources and avoid excessive occupation of the client's hardware operating resources.

[0074] Unless explicitly specified, the various data involved in this application can be stored remotely on a server or on a local terminal device, as long as they are suitable for being called by the technical solution of this application.

[0075] Those skilled in the art should be aware that although the various methods of this application are described based on the same concept and thus exhibit commonality, unless otherwise specified, these methods can be independently executed. Similarly, the various embodiments disclosed in this application are all based on the same inventive concept. Therefore, concepts with the same expression, as well as concepts that are appropriately transformed for convenience despite different expression, should be understood as equivalent.

[0076] Unless expressly stated to be mutually exclusive, the various embodiments disclosed in this application may be cross-combined with the relevant technical features of the various embodiments to flexibly construct new embodiments, as long as such combination does not deviate from the creative spirit of this application and can meet the needs of the prior art or resolve certain deficiencies in the prior art. Those skilled in the art should be aware of such flexibility.

[0077] See also Figures 1 to 4 The toothed disc type electronic mechanical parking mechanism of the present application includes a stator disc arranged on the main shaft of the EMB drive motor and a locking mechanism for locking the stator disc, wherein:

[0078] The stator is fixedly connected to the main shaft of the EMB drive motor;

[0079] The locking mechanism includes a movable disk and a linear drive mechanism for driving the movable disk to perform linear motion, wherein:

[0080] A ratchet structure is provided between the moving disc and the static disc;

[0081] The linear drive mechanism includes a helical gear and a rotary drive mechanism for driving the helical gear to rotate; the helical gear, the movable plate and the static plate are coaxially arranged; the movable plate is fixed on the end face of the helical gear; the helical gear is mounted on the housing of the EMB reducer through 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, and the sliding connection structure includes a plurality of groups of stop-rotation limit pins arranged on the helical gear, and the plurality of groups of stop-rotation limit pins are evenly arranged along the circumferential direction of the helical gear; the housing of the EMB reducer is provided with a plurality of groups of limit holes that cooperate with the stop-rotation limit pins.

[0082] The rotary drive mechanism includes a brush motor and a worm, wherein the worm is mounted on a main shaft of the brush motor, and the worm is meshed with the helical gear in a vertically staggered arrangement.

[0083] See also Figures 1 to 4 The end surface of the static plate close to the dynamic plate is the first locking surface; the end surface of the dynamic plate opposite to the first locking surface of the static plate is the second locking surface; the ratchet structure includes ratchets respectively arranged on the first locking surface and the second locking surface.

[0084] See also Figures 1 to 4The sliding connection structure includes multiple groups of stop-rotation limit pins arranged on the helical gear, and the multiple groups of stop-rotation limit pins are evenly arranged along the circumferential direction of the helical gear; the housing of the EMB reducer is provided with multiple groups of limit holes that cooperate with the stop-rotation limit pins; by setting the stop-rotation limit 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 groups of anti-rotation limit pins.

[0086] See also Figures 1 to 4 A transmission gear is provided on the main shaft of the EMB drive motor; the inner cavity of the stator is provided with a tooth groove that cooperates with the gear teeth of the transmission gear; the stator is interference-mounted on the transmission gear, thereby achieving the installation and fixation of the stator on the main shaft of the EMB drive motor.

[0087] See also Figures 1 to 4 The inner cavity of the helical gear is provided with a spring sheet, one end of which is fixed to the outer shell 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 groups of spring sheets, and by setting up multiple groups of spring sheets, it is used to limit the axial movement of the helical gear, so that the helical gear can only move axially under the rotation of the worm.

[0088] See also Figures 1 to 4 The present invention discloses a toothed disc-type electronic mechanical parking mechanism that arranges a moving disc and a stationary disc on the main shaft of an EMB drive motor; the end surface of the stationary disc close to the moving disc is a first locking surface; the end surface of the moving disc opposite to the first locking surface of the stationary disc is a second locking surface; the ratchet structure includes ratchets provided on the first locking surface and the second locking surface, respectively; the worm is driven to rotate by a brushed motor, thereby pushing the helical gear and the moving disc fixed to the helical gear to perform axial movement, so that the ratchet teeth on the second locking surface of the moving disc engage with the ratchet teeth on the first locking surface of the stationary disc to lock the EMB drive motor, thereby achieving the parking function. In addition, the present invention discloses a toothed disc-type electronic mechanical parking mechanism that achieves parking by engaging the ratchet teeth on the moving disc and the stationary disc; compared with existing common parking structures, the present invention discloses a toothed disc-type electronic mechanical parking mechanism that has high torque density and a small size, making it convenient to deploy on an EMB brake actuator.

[0089] The sprocket-type electronic mechanical parking mechanism of the present application utilizes the reverse motion self-locking function of the vertically staggered meshing worm and bevel gears, and cleverly designs a parking power transmission mechanism to transmit the torque of the power source (brush motor) to the moving plate. After the power source (brush motor) drives the moving plate to clamp the static plate to complete parking, the brush motor can stop working and still maintain the parking force. Compared with most existing parking solutions that use solenoid valves and electromagnetic brakes as power sources, the sprocket-type electronic mechanical parking mechanism of the present application has the advantages of compact structure, low energy consumption and easy deployment.

[0090] See also Figure 5 In one embodiment, the toothed disc type electronic mechanical parking mechanism and the life prediction method thereof of the present application include:

[0091] Step S10: When it is detected that the current parking torque of the crankset-type electronic mechanical parking mechanism is less than the preset parking torque required by the vehicle, the number of tooth pairs of the cranksets in the crankset-type electronic mechanical parking mechanism, the crankset hardness ratio, the crankset clamping force, and the crankset creep rate are obtained;

[0092] The chainring wear life prediction system in the terminal device can respond to an instruction to predict the wear life of the chainring of the chainring-type electronic mechanical parking mechanism, and when it detects that the current parking torque of the chainring-type electronic mechanical parking mechanism is less than the preset parking torque required by the vehicle, obtains the corresponding number of interlocking teeth of the chainring in the chainring-type electronic mechanical parking mechanism, the chainring hardness ratio, the chainring clamping force and the chainring creep rate; wherein, the preset parking torque required by the vehicle may be the theoretical parking torque of the vehicle, and the wear life of the chainring represents the time during which the chainring can still maintain its effective function when its wear level reaches a certain critical point during use; the chainring hardness ratio represents the hardness ratio between the material of the dynamic plate in the chainring and the material of the static plate in contact with it; the chainring clamping force represents the pressure applied between the dynamic plate in the chainring and the static plate in contact with it; and the chainring creep rate represents the relative sliding ratio between the dynamic plate in the chainring and the static plate in contact with it due to insufficient friction.

[0093] In some embodiments, the step of determining the current parking torque of the crankset-type electromechanical parking mechanism includes:

[0094] Step S101: Obtain the parking brake torque, parking brake safety factor, wheel braking radius, and brake disc friction factor of a single wheel side of the vehicle;

[0095] Step S103: calculating and determining a first product between the parking brake torque of a single wheel side of the vehicle and the parking brake safety factor, and determining the braking force of the single wheel side of the vehicle based on a first ratio between the first product and the wheel braking radius;

[0096] Step S105: Determine the piston thrust output by the EMB actuator of a single wheel side based on a second ratio between the braking force of a single wheel side of the vehicle and the friction coefficient of the brake disc, and calculate and determine the current parking torque of the crankset-type electronic mechanical parking mechanism based on the piston thrust output by the EMB actuator.

[0097] Specifically, first, the parking braking torque, parking braking safety factor, wheel braking radius, and brake disc friction factor of a single wheel side of the vehicle are obtained, and the parking braking torque N of a single wheel side of the vehicle is calculated based on the vehicle information; then, the braking force F of a single wheel side of the vehicle during parking is calculated using the parking braking torque N of a single wheel side of the vehicle and the wheel braking radius b according to formula (1): b , which is expressed as:

[0098]

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

[0100] Then, the braking force F of a single wheel side of the vehicle is b and the friction coefficient μ1 of the brake disc, the piston thrust F output by the EMB actuator on a single wheel side during parking can be calculated according to formula (2);

[0101]

[0102] Finally, the current parking torque N required by the main shaft of the EMB drive motor is calculated by calculating the piston thrust F output by the EMB actuator of a single wheel side during parking and the EMB related parameters. This torque is the current parking force of the toothed disc type electronic mechanical parking mechanism, wherein the EMB related parameters include the reducer reduction ratio and the motion conversion mechanism parameters, etc. The motion conversion mechanism includes but is not limited to a screw rod, a force amplification mechanism and a combination thereof.

[0103] Step S20: determining the torque borne by each ratchet tooth in the crankset based on the current parking torque and the number of tooth pairs corresponding to the crankset, and determining the shear force borne by each ratchet tooth in the crankset based on the torque borne by each ratchet tooth, the radius of the stator plate, and the radius of the center hole of the stator plate;

[0104] When it is detected that the current parking torque of the crankset-type electronic mechanical parking mechanism is less than the preset parking torque required by the vehicle, after obtaining the corresponding number of tooth pairs of the crankset in the crankset-type electronic mechanical parking mechanism, the crankset hardness ratio, the crankset clamping force, and the crankset creep rate, the torque borne by each ratchet tooth in the crankset is determined based on the current parking torque and the corresponding number of tooth pairs of the crankset, and the shear force borne by each ratchet tooth in the crankset is determined based on the torque borne by each ratchet tooth, the radius of the stator plate, and the radius of the center hole of the stator plate;

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

[0106] Step S201, obtaining the current parking torque of the crankset type electronic mechanical parking mechanism and the number of corresponding tooth pairs of the crankset;

[0107] Step S203 : determining the torque borne by each ratchet tooth in the crankset according to a third ratio between the current parking torque of the crankset-type electronic mechanical parking mechanism and the number of pairs of teeth corresponding to the crankset.

[0108] The chainring wear life prediction system in the terminal device can obtain the current parking torque N of the chainring type electronic mechanical parking mechanism and the number of interlocking teeth C corresponding to the chainring; according to the third ratio between the current parking torque N of the chainring type electronic mechanical parking mechanism and the number of interlocking teeth C corresponding to the chainring, the torque N borne by each ratchet in the chainring is determined. C , wherein the torque N borne by each ratchet tooth in the crankset C The expression is:

[0109]

[0110] Among them, the N C It represents the torque borne by each ratchet tooth in the chainring, N represents the current parking torque of the chainring type electronic mechanical parking mechanism, and C represents the number of corresponding tooth pairs of the chainring.

[0111] In a further embodiment, the step of determining the shear force borne by each ratchet tooth in the crankset according to the torque borne by each ratchet tooth, the radius of the stator plate, and the radius of the center hole of the stator plate includes:

[0112] Step S2001, obtaining the torque borne by each ratchet tooth in the crankset, the radius of the stator plate, and the radius of the center hole of the stator plate;

[0113] Step S2003: Calculate and determine a first difference between the radius of the stator plate and the radius of the center hole of the stator plate, and determine the shear force borne by each ratchet in the crankset based on a fourth ratio between the torque borne by each ratchet and the first difference.

[0114] After determining the torque borne by each ratchet in the crankset, the torque N borne by each ratchet in the crankset is obtained. C , the radius R of the static disk and the radius r of the center hole of the static disk; calculating and determining a first difference between the radius R of the static disk and the radius r of the center hole of the static disk, according to the torque N borne by each ratchet C and the first difference to determine the shear force F borne by each ratchet tooth in the crankset. C ; Wherein, the shear force F borne by each ratchet in the tooth plate C The expression is:

[0115]

[0116] Among them, F C Indicates the shear force borne by each ratchet in the tooth plate, N C It represents the torque borne by each ratchet tooth in the chainring, R represents the radius of the stator plate, and r represents the radius of the center hole of the stator plate.

[0117] Step S30: determining the radial cross-sectional area of each ratchet tooth according to the radius of the stator disk, the radius of the center hole of the stator disk, and the number of pairs of teeth; and determining 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;

[0118] 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, determining the shear force borne by each ratchet tooth in the crankset based on the torque borne by each ratchet tooth, the radius of the stator plate, and the radius of the center hole of the stator plate, then determining the radial cross-sectional area of each ratchet tooth based on the radius of the stator plate, the radius of the center hole of the stator plate, and the number of interlocking tooth pairs, and determining the shear strength borne by each ratchet tooth based on the shear force borne by each ratchet tooth and the radial cross-sectional area of each ratchet tooth;

[0119] In some embodiments, the step of determining the radial cross-sectional area of each ratchet tooth based on the radius of the stator disk, the radius of the center hole of the stator disk, and the number of pairs of teeth, and determining the shear strength borne by each ratchet tooth based on the shear force borne by each ratchet tooth and the radial cross-sectional area of each ratchet tooth includes:

[0120] Step S301, obtaining the radius of the stator disc, the radius of the center hole of the stator disc, the number of pairs of teeth, and the shear force borne by each ratchet;

[0121] Step S303: Calculate and determine a second difference between a first square value of the radius of the stator disk and a second square value of the radius of the central hole of the stator disk, and calculate and determine a second product between the second difference and pi;

[0122] Step S305: Calculate and determine a fifth ratio between the second product and twice the number of pairs of teeth to determine the radial cross-sectional area of each ratchet tooth;

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

[0124] The toothed disc wear life prediction system in the terminal device can obtain the radius R of the static disc, the radius r of the center hole of the static disc, the number of teeth C, and the shear force F borne by each ratchet tooth. C Calculate and determine a second difference between a first square value of the radius R of the stator disk and a second square value of the radius r of the center hole of the stator disk, and calculate and determine a second product between the second difference and pi π; calculate and determine a fifth ratio between the second product and twice the number of pairs of teeth to determine the radial cross-sectional area S of each ratchet tooth; wherein the expression for 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 number of pairs of teeth, R represents the radius of the static disk, r represents the radius of the center hole of the static disk, and π represents the pi.

[0127] Furthermore, after determining the radial cross-sectional area S of each ratchet, the shear force F borne by each ratchet is calculated. C and the radial cross-sectional area S of each ratchet tooth to determine the shear strength τ1 borne by each ratchet tooth, wherein the shear strength τ1 borne by each ratchet tooth is expressed as:

[0128]

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

[0130] A safety constraint is imposed on the shear strength τ1 borne by each ratchet, namely:

[0131] τ1≤Kτ allow (7)

[0132] Among them, τ allow Indicates the allowable shear strength of the materials of the moving and static discs, K represents the safety factor, and K is less than 1;

[0133] In some embodiments, the torque N borne by each ratchet can be C , the number of teeth C, the allowable shear strength τ of the material of the moving and static discs allow (τ a ), safety factor K, radius R of the static disk and radius r of the center hole of the static disk, a calculation model for the minimum static disk radius is constructed, which is expressed as:

[0134]

[0135] Where R is the radius of the stator, r is the radius of the center hole of the stator (determined by the motor shaft), C is the number of pairs of phase teeth, K is the safety factor, and τ a Indicates the allowable shear strength of the material of the moving and static discs, N C Indicates the torque borne by each ratchet tooth.

[0136] Under the premise of satisfying safety constraints, the above-constructed minimum static disk radius calculation model is solved to obtain the minimum static disk radius R.

[0137] Step S40: inputting a feature data set constructed by 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 crankset hardness ratio, the crankset clamping force, and the crankset creep rate into a prediction model to be trained, and calculating an output error between the predicted wear life of the crankset and the actual wear life;

[0138] Step S50: If the output error is less than the preset error, the current prediction model to be trained is used as the chainring wear life prediction model to predict the chainring wear life, thereby completing the chainring wear life prediction of the chainring type electronic mechanical parking mechanism.

[0139] After calculating and determining 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, the feature 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 chainring hardness ratio, the chainring clamping force, and the chainring creep rate is input into the prediction model to be trained, and the output error between the predicted value of the wear life of the chainring 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 chainring wear life prediction model to predict the wear life of the chainring, and complete the chainring wear life prediction of the chainring type electronic mechanical parking mechanism, wherein the basic network architecture of the prediction model to be trained and the chainring wear life prediction model is a back propagation neural network.

[0140] In some embodiments, see Figure 6 The step of training the chainring wear life prediction model comprises:

[0141] Step S501: Acquire a feature data set, wherein the feature data set includes a plurality of feature data samples and their corresponding wear life label values;

[0142] Step S503: Initialize the prediction model to be trained, randomly assign network weight values and biases of the prediction model to be trained, and randomly select the first feature data sample;

[0143] Step S505: forwardly calculate and obtain the output of each hidden layer and the output of the output layer in the prediction model to be trained, and calculate and determine the output error between the output of the output layer and the actual wear life of the crankset, wherein the output of the output layer represents the predicted value of the wear life of the crankset;

[0144] Step S507: If the output error is greater than or equal to a preset error threshold, backpropagate the output error 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;

[0145] Step S509 , looping the above steps until the output error is less than the preset error threshold or reaches a preset number of iterations, so as to complete the training of the chainring wear life prediction model.

[0146] Specifically, a parking mechanism sample proposed in this application is manufactured according to the design parameters and material requirements and deployed to the EMB actuator terminal at the same time. Subsequently, the actual vehicle parking conditions are simulated on the test bench. Parking conditions under various conditions such as parking, releasing parking, and temporary parking during driving are collected in stages and working conditions. According to single or multiple variables such as 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, multiple different chainring hardness ratios, different chainring clamping forces, different motor speeds, chainring creep rates, different operating temperatures, and different working cycles, a reasonable test bench working condition spectrum is set according to the actual vehicle working conditions. Then, relevant information such as the chainring, working condition information, and wear results are collected strictly in accordance with the test plan. To meet the requirements of the actual vehicle deployment application of the model, this application uses the chainring material parameters as compensation information, which can be used as design vehicle information input, and the working condition and environmental parameters as the main input information, which can be obtained and recorded in real time by relevant sensors of the actual vehicle.

[0147] After completing signal data acquisition, the data sets collected at different stages and under different operating conditions are preprocessed. Gaussian filters are used to filter the collected load, temperature, speed, friction, duty cycle, and vibration signals to remove noise from the sensor signals and reduce their impact on model training accuracy. The data is then normalized to ensure that the data ranges of each feature signal are consistent, preventing excessively large numerical ranges of certain features from affecting model training.

[0148] Furthermore, due to the complex working conditions of the double-crank clamping wear test of the parking mechanism, in order to overcome the problem of limited data volume and improve the robustness and generalization ability of the model after training, this application uses Generative Adversarial Networks (GAN) to enhance the collected data. GAN consists of a generator and a discriminator. Through 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 amount of wear and parameter information data while maintaining the diversity and authenticity of the data.

[0149] Furthermore, the present application proposes to use a back propagation neural network (BPNN) as the chainring wear life prediction model of the present application, and trains the back propagation neural network using data such as 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, a variety of different chainring hardness ratios, different chainring clamping forces, different motor speeds, chainring creep rates, and different operating temperatures to predict the chainring wear life of the chainring type electronic mechanical parking mechanism. In the back propagation neural network (BPNN), the neurons of the back propagation neural network (BPNN) are interconnected through weights, the signal is forward propagated between the layers of the network, and the error is adjusted by the back propagation mechanism to optimize the model performance.

[0150] Then, see Figure 7 , Figure 7 The detailed calculation process based on the back propagation neural network (BPNN) is shown. The network consists of three layers: input layer, hidden layer, and output layer. The input layer and 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"). The connections between layers are represented by the 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 is added to form the input of the hidden layer (Hidden Layer), that is, Wx+b. Subsequently, the input is processed by the nonlinear activation function f(x) to generate the outputs a1, a2, and a3 of the hidden layer; then, the output is combined with the corresponding weights and bias terms as the input of the output layer (Output Layer), and is processed again by the activation function to finally generate the output result of the network. Equation (9) shows the mathematical relationship from the input layer to the hidden layer, which is expressed as:

[0153]

[0154] Among them, y m represents the input of the input layer, yt represents the predicted value at point t, μ jm represents the network weight of the output layer, μ j represents the threshold of the hidden layer, n represents the number of nodes in the input layer, f l represents the activation function of the hidden layer.

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

[0156]

[0157] Among them, y represents the input of the hidden layer, y t represents the predicted value of point t; λ om represents the network weight of the hidden layer, λ o represents the threshold of the output layer, l represents the number of nodes in the hidden layer, and f o Represents the activation function of the output layer. Generally, the logical function and hyperbolic function are usually used as the activation function f of the hidden layer. l , a linear function can be used as the activation function f of the output layer o .

[0158] Furthermore, in order to evaluate the prediction performance of the model, this application proposes to use the root mean square error (RMSE), minimum root mean square error (LE), mean absolute error (MAE) and coefficient of determination (R 2 ). Among them, RMSE is used to reflect the overall error level between the model prediction value and the true value, which can highlight the impact of large errors; MAE is an intuitive indicator that can quickly understand the average error level of the model; R 2 The smaller the RMSE and MAE values of the model, the better the R 2 The larger the value is, the more suitable the model is for predicting the wear life of the toothed disc of the toothed disc type electronic mechanical parking mechanism of the present application.

[0159]

[0160] Where y m is the true value of the data sample, is the mean of the true values, y' m is the predicted value.

[0161] Trained models 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 retrained to ensure continuous improvement in prediction accuracy.

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

[0163] As can be seen from the above embodiments, compared with the prior art, the present application addresses the problem that, after a long period of static friction, each ratchet in the chainring of the prior art chainring type electronic mechanical parking mechanism will be worn out, which may cause the parking mechanism to fail at best, or even cause safety accidents such as the vehicle rolling away and injuring people at worst. The present application includes but is not limited to the following beneficial effects:

[0164] First, this application establishes a chainring wear life prediction model based on the back propagation neural network (BPNN) and takes into account multiple important factors, such as the torque, shear force, radial cross-sectional area, shear strength, chainring hardness ratio, clamping force and creep rate borne by the ratchet, to accurately predict the wear life of the chainring. 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, the present application can significantly improve the safety of a chainring-based electronic mechanical parking mechanism. By predicting the wear life of the chainring, measures can be taken before the wear reaches a critical point, thus avoiding the problem of the vehicle rolling away due to failure of the parking mechanism. The safety hazard caused by rolling away may lead to serious traffic accidents, and this prediction method can greatly reduce this risk.

[0166] Third, the present application can significantly reduce maintenance costs. The chainring wear life prediction model of the present application can monitor the wear status of the chainring in real time, thereby helping vehicle operators or owners to detect problems in advance and perform repairs, avoiding unnecessary frequent inspections and premature replacements, and also avoiding expensive repair costs caused by sudden failures.

[0167] Fourthly, this application can significantly improve the reliability and lifespan of the parking mechanism. By real-time monitoring and prediction of sprocket wear, the parking mechanism's operating conditions and maintenance cycles can be continuously optimized in practice. This improves the overall reliability and service life of the sprocket-type electromechanical parking mechanism, thereby reducing the failure rate and maintenance requirements during long-term operation.

[0168] To sum up, the life prediction method of the sprocket-type electronic mechanical parking mechanism of the present application has significant practical value, can effectively solve the failure and safety problems caused by sprocket wear in the sprocket-type electronic mechanical parking mechanism, and provides important technical guarantees for the safety, economy and intelligent development of intelligent transportation systems.

[0169] See also Figure 8A sprocket wear life prediction device in a sprocket-type electronic mechanical parking mechanism is provided to meet one of the purposes of this application, including 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. Among them, the wear life prediction trigger module 1100 is configured to obtain the corresponding number of tooth pairs of 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 when it detects 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 shear force determination module 1200 is configured to determine 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 determine 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 radius of the center hole of the static disc; the shear strength determination module 1300 is configured to determine the radial cross-sectional area of each ratchet according to the radius of the static disc, the radius of the center hole of the static disc and the number of tooth pairs, and determine the radial cross-sectional area of each ratchet according to the radius of each The shear force borne by the ratchet and the radial cross-sectional area of each ratchet are used to determine the shear strength borne by each ratchet; the output error determination module 1400 is configured to use 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 chainring hardness ratio, the chainring clamping force and the chainring creep rate to construct a feature data set to be input into the prediction model to be trained, and calculate the output error between the predicted value of the wear life of the chainring and the actual wear life; the wear life prediction module 1500 is configured to use the current prediction model to be trained as the chainring wear life prediction model if the output error is less than the preset error, so as to predict the wear life of the chainring and complete the chainring wear life prediction of the chainring type electronic mechanical parking mechanism.

[0170] Based on any embodiment of this application, please refer to Figure 9 Another embodiment of the present application further provides an electronic device, which can be implemented by a computer device, such as Figure 9As shown, a schematic diagram of the internal structure of a computer device. The computer device includes a processor, a computer-readable storage medium, a memory, and a network interface connected via a system bus. The computer-readable storage medium of the computer device stores an operating system, a database, and computer-readable instructions. The database may store a control information sequence. When the computer-readable instructions are executed by the processor, the processor may implement a method for predicting the life of a crankset-type electronic mechanical parking mechanism. The processor of the computer device is used to provide computing and control capabilities to support the operation of the entire computer device. The memory of the computer device may store computer-readable instructions. When the computer-readable instructions are executed by the processor, the processor may execute the method for predicting the life of a crankset-type electronic mechanical parking mechanism of the present application. The network interface of the computer device is used to connect and communicate with a terminal. Those skilled in the art will understand that Figure 9 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0171] In this embodiment, the processor is used to execute Figure 8 The memory stores the program code and various data required to execute the modules. The network interface is used to transmit data between user terminals or servers. The memory in this embodiment stores the program code and data required to execute all modules in the crankset wear life prediction device for the crankset-type electronic mechanical parking mechanism of this application. The server can call the server's program code and data to execute the functions of all modules.

[0172] The present application also provides a storage medium storing computer-readable instructions. When the computer-readable instructions are executed by one or more processors, the one or more processors execute the steps of the method for predicting the life of a crankset-type electronic mechanical parking mechanism described in any embodiment of the present application.

[0173] The present application also provides a computer program product, including a computer program / instruction, which, when executed by one or more processors, implements the steps of the method for predicting the life of a crankset-type electronic mechanical parking mechanism described in any embodiment of the present application.

[0174] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments of the present application can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above-mentioned embodiments of the method. The aforementioned storage medium can be a computer-readable storage medium such as a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

[0175] The above description is only part of the implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A toothed disc type electronic mechanical parking mechanism, characterized in that: It includes a stator plate arranged on the main shaft of the EMB drive motor and a locking mechanism for locking the stator plate, wherein: The stator is fixedly connected to the main shaft of the EMB drive motor; The locking mechanism includes a movable plate and a linear drive mechanism for driving the movable plate to perform linear motion; a ratchet structure is provided between the movable plate and the static plate; the linear drive mechanism includes a helical gear and a rotary drive mechanism for driving the helical gear to rotate; wherein, The helical gear, the movable plate, and the stationary plate are coaxially arranged; the movable plate 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 axis of the main shaft of the EMB drive motor; The rotary drive mechanism includes a motor and a worm, wherein the worm is mounted on the main shaft of the motor and meshes with the helical gear in a vertically staggered arrangement.

2. The crankset type electromechanical parking mechanism according to claim 1, characterized in that: The end surface of the static plate close to the dynamic plate is the first locking surface; the end surface of the dynamic plate opposite to the first locking surface of the static plate is the second locking surface; the ratchet structure includes ratchets respectively arranged on the first locking surface and the second locking surface.

3. The crankset type electromechanical parking mechanism according to claim 2, characterized in that: The sliding connection structure includes multiple groups of anti-rotation limit pins arranged on the helical gear, and the multiple groups of anti-rotation limit pins are evenly arranged along the circumferential direction of the helical gear; the housing of the EMB reducer is provided with multiple groups of limit holes that cooperate with the anti-rotation limit pins.

4. A life prediction method for a crankset-type electromechanical parking mechanism, applied to the crankset-type electromechanical parking mechanism according to any one of claims 1 to 3, characterized in that: include: When it is detected that the current parking torque of the crankset-type electronic mechanical parking mechanism is less than the preset parking torque required by the vehicle, the number of tooth pairs of the cranksets in the crankset-type electronic mechanical parking mechanism, the crankset hardness ratio, the crankset clamping force, and the crankset creep rate are obtained; wherein the crankset includes a stationary plate and a dynamic plate; Determining the torque borne by each ratchet tooth in the crankset based on the current parking torque and the number of teeth corresponding to the crankset, and determining the shear force borne by each ratchet tooth in the crankset based on the torque borne by each ratchet tooth, the radius of the stator plate, and the radius of the center hole of the stator plate; Determine the radial cross-sectional area of each ratchet tooth according to the radius of the stator disk, the radius of the center hole of the stator disk, and the number of pairs of teeth; 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; A feature data set constructed by 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 chainring hardness ratio, the chainring clamping force, and the chainring creep rate is input into the prediction model to be trained, and an output error between the predicted wear life value and the actual wear life of the chainring is calculated; If the output error is less than the preset error, the current prediction model to be trained is used as the chainring wear life prediction model to predict the chainring wear life, thereby completing the chainring wear life prediction of the chainring type electronic mechanical parking mechanism.

5. The life prediction method of the crankset type electronic mechanical parking mechanism according to claim 4, characterized in that: The step of determining the current parking torque of the toothed disc type electromechanical parking mechanism comprises: Obtain the parking brake torque, parking brake safety factor, wheel braking radius, and brake disc friction factor of a single wheel side of the vehicle; calculating and determining a first product between the parking brake torque of a single wheel side of the vehicle and the parking brake safety factor, and determining the braking force of the single wheel side of the vehicle based on a first ratio between the first product and the wheel braking radius; The piston thrust output by the EMB actuator of a single wheel side is determined based on a second ratio between the braking force of a single wheel side of the vehicle and the friction coefficient of the brake disc, and the current parking torque of the crankset-type electronic mechanical parking mechanism is determined based on the piston thrust output by the EMB actuator.

6. The life prediction method of the crankset type electronic mechanical parking mechanism according to claim 4, characterized in that: The step of determining the torque borne by each ratchet tooth in the crankset according to the current parking torque and the number of teeth pairs corresponding to the crankset comprises: Obtain the current parking torque of the toothed disc type electronic mechanical parking mechanism and the number of tooth pairs corresponding to the toothed disc; The torque borne by each ratchet tooth in the crankset is determined according to a third ratio between the current parking torque of the crankset type electronic mechanical parking mechanism and the number of pairs of teeth corresponding to the crankset.

7. The life prediction method of the crankset type electronic mechanical parking mechanism according to claim 4, characterized in that: The step of determining the shear force borne by each ratchet tooth in the crankset according to the torque borne by each ratchet tooth, the radius of the stator plate, and the radius of the center hole of the stator plate comprises: Obtaining the torque borne by each ratchet tooth in the crankset, the radius of the stator disc, and the radius of the center hole of the stator disc; A first difference between the radius of the stator plate and the radius of the center hole of the stator plate is calculated and determined, and a shear force borne by each ratchet in the crankset is determined based on a fourth ratio between the torque borne by each ratchet and the first difference.

8. The life prediction method of the crankset type electronic mechanical parking mechanism according to claim 4, characterized in that: The steps of determining the radial cross-sectional area of each ratchet tooth according to the radius of the stator disk, the radius of the center hole of the stator disk, and the number of pairs of teeth, and determining 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 include: Obtain the radius of the stator disc, the radius of the center hole of the stator disc, the number of teeth in each pair, and the shear force borne by each ratchet tooth; calculating and determining a second difference between a first square value of the radius of the stator disk and a second square value of the radius of the central hole of the stator disk, and calculating and determining a second product between the second difference and pi; calculating a fifth ratio between the second product and twice the number of pairs of teeth to determine the radial cross-sectional area of each ratchet tooth; The shear strength borne by each ratchet tooth is determined according to a sixth ratio between the shear force borne by each ratchet tooth and the radial cross-sectional area of each ratchet tooth.

9. The life prediction method of the crankset type electronic mechanical parking mechanism according to claim 4, characterized in that: The step of training the chainring wear life prediction model comprises: Acquire a feature data set, wherein the feature data set includes a plurality of feature data samples and their corresponding wear life label values; Initializing the prediction model to be trained, randomly assigning network weight values and biases of the prediction model to be trained, and randomly selecting the first feature data sample; forwardly calculating the output of each hidden layer and the output of the output layer in the prediction model to be trained, and calculating and determining the output error between the output of the output layer and the actual wear life of the crankset, wherein the output of the output layer represents the predicted value of the wear life of the crankset; If the output error is greater than or equal to a preset error threshold, backpropagating the output error 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; The above steps are repeated 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 chainring wear life prediction model.

10. The life prediction method of the crankset type electronic mechanical parking mechanism according to claim 4, characterized in that: The basic network architecture of the prediction model to be trained and the chainring wear life prediction model is a back propagation neural network; The wear life of the crankset indicates the time during which the crankset can maintain effective function when its wear reaches a certain critical point during use; The crankset hardness ratio represents the hardness ratio between the crankset material and the crankset material in contact with the crankset. The tooth plate clamping force represents the pressure applied between the dynamic plate and the static plate in contact with the dynamic plate in the tooth plate; The crankset creep rate represents the relative sliding ratio between the dynamic crankset and the static crankset in contact therewith due to insufficient friction.

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