A clutch creeping working condition health state evaluation method and system based on digital twinning

Abstract

The application discloses a clutch creeping working condition health state evaluation method and system based on digital twinning, and the method comprises the following steps: acquiring real vehicle running data, and constructing a clutch twin body; inputting the real vehicle running data into the clutch twin body; identifying the real vehicle creeping working condition; if the real vehicle running data meets the preset condition, activating the real vehicle creeping function, controlling the creeping speed, and calculating the creeping sliding friction work; comparing the creeping sliding friction work with the safety sliding friction work threshold, evaluating the clutch health state, and executing the health management strategy of the clutch based on the health state evaluation result. The application is beneficial to stabilizing the real vehicle entity creeping speed and prolonging the service life of the clutch.

Description

Technical Field

[0001] This invention relates to the field of vehicle clutch health status monitoring technology, and in particular to a method and system for assessing the health status of a clutch under creeping conditions based on digital twins. Background Technology

[0002] With the rapid development of the automotive industry, urban roads are becoming increasingly congested. In congested urban traffic, vehicles often use a semi-engaged clutch to move slowly at low speeds, achieving controllable power output through the slippage of the clutch friction pairs – a condition known as creeping. However, during prolonged slippage, the clutch friction pairs generate and accumulate a large amount of frictional heat, causing the temperature of the friction pairs to rise and the coefficient of friction to change. This not only causes fluctuations in the vehicle's output torque, leading to vehicle speed instability, but also, excessively high friction plate temperatures can cause clutch failure, resulting in even more serious consequences.

[0003] Currently, experts and scholars are focusing on vehicle speed control methods under crawling conditions. A method and system for rapidly controlling vehicle crawling torque is being developed, adaptable to different road conditions and capable of quickly responding to output crawling torque. The vehicle crawling control method, medium, vehicle controller, and automatic transmission vehicle can achieve rapid and precise output of crawling torque, improving the vehicle's crawling control effect. A vehicle crawling control method, device, equipment, and storage medium allow the driver to adjust the crawling speed. The vehicle crawling control method, medium, vehicle controller, and automatic transmission vehicle can avoid the problem of engine speed drop or even stalling when the vehicle enters crawling conditions under special environments such as low temperatures and high altitudes. However, the above technologies and methods are all aimed at vehicle speed control under crawling conditions and do not consider the safety and reliability of the clutch during the crawling process. When the crawling time is too long, the friction elements accumulate excessively high temperatures, which can lead to clutch failure and serious consequences such as loss of vehicle control. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a method and system for assessing the health status of a clutch during crawling operation based on digital twins. This method intervenes in the health status of the clutch entity in real time based on real-time slip friction work, thereby improving the reliability and safety of vehicle crawling.

[0005] On the one hand, to achieve the above objectives, the present invention provides a method for assessing the health status of a clutch under creeping operating conditions based on digital twins, comprising:

[0006] Acquire real vehicle operation data and construct a clutch twin. Input the real vehicle operation data into the clutch twin to identify the real vehicle creeping condition. If the real vehicle operation data meets the preset conditions, activate the real vehicle creeping function, control the creeping speed, and calculate the creeping friction work.

[0007] The creeping friction work is compared with the safe friction work threshold, and the health status of the clutch is evaluated based on the comparison results. Based on the health status evaluation results, a health management strategy is implemented for the clutch.

[0008] Preferably, the preset condition is:

[0009]

[0010] In the formula, v is the real-time vehicle speed, a is the vehicle acceleration, α is the brake pedal opening value, and β is the accelerator pedal opening value.

[0011] Preferably, controlling the creeping speed based on a creeping control strategy includes:

[0012] The target vehicle speed of the clutch twin is set to v. x The vehicle's actual speed v and target speed v x The deviation Δv is the input, the friction pair pressure of the clutch body is the output, and the control target is that Δv approaches 0, then the vehicle body will drive stably, and the speed n1 of the active end of the clutch body is greater than the speed n2 of the passive end.

[0013] Preferably, the creep control strategy is as follows:

[0014]

[0015] In the formula, F is the pressure of the physical friction pair of the clutch, λ1, λ2, and λ3 are the proportional constant, integral constant, and derivative constant of the PID controller, respectively, and t is time.

[0016] Preferably, the method for calculating the creeping friction work is as follows:

[0017]

[0018] In the formula, μ is the coefficient of friction, and r e K is the radius of frictional side effect. n Z is the clamping force reduction coefficient, Z is the number of friction pairs; Q(q) is the forced cooling power of the clutch, q is the lubrication flow rate, and T is the clamping force reduction coefficient. f ω1 is the friction torque, F is the pressure of the clutch physical friction pair, ω2 is the angular velocity of the clutch driving end, ω2 is the angular velocity of the clutch driven end, W is the creeping friction work, n1 is the speed of the clutch physical driving end, and n2 is the speed of the clutch physical driven end.

[0019] Preferably, the safe friction work threshold is:

[0020]

[0021] In the formula, T0 is the friction torque threshold, p is the normal engagement oil pressure of the clutch body, A is the contact area of ​​the friction pair, n0 is the stable speed of the clutch body during long-term slippage, t0 is the allowable long-term slippage time of the clutch body, ω0 is the maximum angular acceleration difference of the clutch, and W0 is the safe slippage power threshold.

[0022] Preferably, assessing the health status of the clutch includes:

[0023] The relative error between the creeping friction work and the safe friction work threshold is compared, and the health status of the clutch entity is evaluated by the relative error. If the relative error is less than or equal to the first preset value, the constant speed creeping continues. If the relative error is greater than the first preset value and less than or equal to the second preset value, the clutch twin is intervened. If the relative error is greater than the second preset value, the driver needs to intervene.

[0024] The relative error is:

[0025] In the formula, b is the relative error between creeping friction work and the safe friction work threshold, W is the creeping friction work, and W0 is the safe friction work threshold.

[0026] Preferably, the intervention through the clutch twin is as follows: the clutch twin sends a signal to the vehicle body to adjust the lubrication flow of the clutch body to the maximum value and increase the forced heat dissipation power of the clutch body;

[0027] The driver's intervention is as follows: a signal is sent to the vehicle body through the clutch twin to adjust the lubrication flow of the clutch body to the maximum value, and an alarm dialog box pops up on the vehicle body display screen, prompting the driver to release the brake pedal.

[0028] Preferably, the method further includes performing limp detection. When the driver releases the pedal, the clutch twin continuously calculates the creep friction work W. When the relative error b < 50%, the clutch twin sends a signal to the vehicle body to adjust the lubrication flow of the clutch body to the normal value and restarts creep recognition to prompt the driver to continue to perform creep mode.

[0029] On the other hand, in order to achieve the above objectives, the present invention also provides a clutch creep condition health status assessment system based on digital twins, comprising:

[0030] Data acquisition and transmission unit: used to collect sensor data of the vehicle entity, transmit the sensor data of the vehicle entity to the clutch twin, and send the twin data and instructions of the clutch twin to the vehicle entity;

[0031] Clutch digital twin unit: used to construct a clutch twin based on the operating status of the clutch entity, and to transmit the sensor data of the vehicle entity to the clutch twin wirelessly;

[0032] Creep identification unit: used to identify the creeping condition of the vehicle entity based on the vehicle entity data received by the clutch twin, and activate the creeping function of the clutch twin;

[0033] Crawl speed control unit: used to send instructions to the vehicle entity through the data acquisition and transmission unit to execute the crawl control strategy;

[0034] Slip friction work calculation unit: used to calculate the clutch creep slip friction work W and the safe slip friction work threshold W0 after the clutch twin is activated in creep mode;

[0035] Health status assessment unit: used to assess the health status of the clutch entity by measuring the relative error between the creeping friction work and the safe friction work threshold;

[0036] Health management unit: Used to manage health based on the results of health status assessment;

[0037] Limp detection unit: Used to monitor the limpness of the vehicle body. When the clutch body meets the health management requirements, the clutch twin re-engages the crawl recognition and prompts the driver to continue to execute the crawl mode.

[0038] Compared with the prior art, the present invention has the following advantages and technical effects:

[0039] 1. This invention utilizes real-time data mapping between the vehicle entity and the clutch twin to calculate the clutch slippage work of the vehicle entity during the creeping process in real time, and to evaluate the health status of the clutch entity in real time. It has good real-time performance and high reliability. Furthermore, this invention can intervene in the health status of the clutch entity in real time based on the real-time slippage work, which can improve the reliability and safety of vehicle creeping.

[0040] 2. The clutch twin of the present invention can adjust the forced lubrication flow of the clutch body according to the health status of the clutch body or the driver intervention adjustment, which is beneficial to stabilizing the vehicle's creep speed and extending the service life of the clutch.

[0041] 3. Based on the health management method of the clutch twin, this invention provides different health management prompts for clutch entities in different health states, and provides creeping recovery prompts to facilitate driver operation. Attached Figure Description

[0042] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0043] Figure 1 This is a flowchart of a clutch creep condition health status assessment method based on digital twin according to an embodiment of the present invention;

[0044] Figure 2 This is a schematic diagram of a clutch creep condition health status assessment system based on digital twin according to an embodiment of the present invention. Detailed Implementation

[0045] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0046] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0047] This invention proposes a method for assessing the health status of a clutch under creeping operating conditions based on digital twins, such as... Figure 1 ,include:

[0048] Acquire real vehicle operation data and construct a clutch twin. Input the real vehicle operation data into the clutch twin to identify the real vehicle creeping condition. If the real vehicle operation data meets the preset conditions, activate the real vehicle creeping function, control the creeping speed, and calculate the creeping slip work.

[0049] Specifically, in this embodiment, the real vehicle operation data is the real-time operation data of the vehicle entity that the sensor immediately collects when the driver releases the brake, including: real-time vehicle speed v, vehicle acceleration a, brake pedal opening value α, throttle opening value β, and clutch active and passive end angular velocities n1 and n2.

[0050] Based on the physical clutch, a clutch twin is created, and the vehicle physical data is transmitted to the clutch twin wirelessly.

[0051] If the actual vehicle operation data meets the preset conditions, the actual vehicle creep function is activated, the creep speed is controlled, and the creep friction work is calculated, specifically:

[0052] Based on the vehicle entity data received by the clutch twin, if the real-time operating data of the vehicle entity meets the preset conditions, the vehicle entity crawling function is activated.

[0053] The preset conditions are:

[0054]

[0055] In the formula, v is the real-time vehicle speed, a is the vehicle acceleration, α is the brake pedal opening value, and β is the accelerator pedal opening value.

[0056] After activating the crawl mode, the crawl speed is controlled based on the crawl control strategy: the target speed of the clutch twin is set to v. x The vehicle's actual speed v and target speed v x The deviation Δv is the input, the friction pair pressure of the clutch body is the output, and the control target is that Δv approaches 0, then the vehicle body will drive stably, and the speed n1 of the active end of the clutch body is greater than the speed n2 of the passive end.

[0057] Furthermore, the creep control strategy is as follows:

[0058]

[0059] In the formula, F is the pressure of the physical friction pair of the clutch, λ1, λ2, and λ3 are the proportional constant, integral constant, and derivative constant of the PID controller, respectively, and t is time.

[0060] After the clutch twin is activated into creep mode, the twin sliding work W of the clutch twin is immediately calculated:

[0061]

[0062] In the formula, μ is the coefficient of friction, and r e K is the radius of frictional side effect. n Z is the coefficient for reducing clamping force; Q(q) is the number of friction pairs; Q(q) is the forced cooling power of the clutch; and q is the lubrication flow rate, which is a function of q.

[0063] Calculate the safe slippage work threshold W0 of the clutch twin:

[0064]

[0065] In the formula, p is the normal engagement oil pressure of the clutch body; A is the contact area of ​​the friction pair; n0 is the stable speed of the clutch body under long-term slippage; and t0 is the allowable long-term slippage time of the clutch body.

[0066] The creeping friction work is compared with the safe friction work threshold. The health status of the clutch is assessed by the comparison results, and a health management strategy is implemented for the clutch based on the health status assessment results.

[0067] Compare the relative error between the twin friction work W and the safe friction work threshold W0. A health status assessment of the clutch body is conducted.

[0068] Specifically, if the relative error is less than or equal to the first preset value, continue the constant-speed creep. If the relative error is greater than the first preset value and less than or equal to the second preset value, intervene through the clutch twin. If the relative error is greater than the second preset value, the driver needs to intervene, as shown in the following formula:

[0069]

[0070] When b ≤ 70%, the clutch entity is within the safe range and the constant-speed creep can continue. When 70% < b ≤ 85%, the clutch entity is within the dangerous range and the clutch twin needs to intervene. The clutch twin sends a signal to the vehicle entity to adjust the lubrication flow rate of the clutch entity to the maximum value and increase the forced heat dissipation power Q(q) of the clutch entity. When b > 85%, the clutch entity is within the dangerous range and the driver needs to intervene. The clutch twin sends a signal to the vehicle entity to adjust the lubrication flow rate of the clutch entity to the maximum value, and an alarm dialog box pops up on the display screen of the vehicle entity to prompt the driver to release the brake pedal.

[0071] The method further includes performing a limp-home monitoring, specifically:

[0072] After the driver releases the pedal, the clutch twin continuously calculates the twin sliding friction work W. When b < 50%, the clutch twin sends a signal to the vehicle entity to adjust the lubrication flow rate of the clutch entity to the normal value and restart the creep identification, prompting the driver that the creep mode can be continued.

[0073] This embodiment also provides a health state assessment system for the clutch creep working condition based on digital twin, as Figure 2 , including:

[0074] Data acquisition and transmission unit: used to collect the sensor data of the vehicle entity, transmit the sensor data of the vehicle entity to the clutch twin, and send the twin data and instructions of the clutch twin to the vehicle entity;

[0075] Clutch digital twin unit: used to construct the clutch twin according to the operating state of the clutch entity, and send the sensor data of the vehicle entity to the clutch twin by wireless transmission;

[0076] Creep identification unit: used to identify the creep working condition of the vehicle entity according to the vehicle entity data received by the clutch twin, and activate the creep function of the clutch twin;

[0077] Creep vehicle speed control unit: used to send instructions to the vehicle entity through the data acquisition and transmission unit to execute the creep control strategy;

[0078] Slip friction work calculation unit: used to calculate the clutch creep slip friction work W and the safe slip friction work threshold W0 after the clutch twin is activated in creep mode;

[0079] Health status assessment unit: used to assess the health status of the clutch entity by measuring the relative error between the creeping friction work and the safe friction work threshold;

[0080] Health management unit: Used to manage health based on the results of health status assessment;

[0081] Limp detection unit: Used to monitor the limpness of the vehicle body. When the clutch body meets the health management requirements, the clutch twin re-engages the crawl recognition and prompts the driver to continue to execute the crawl mode.

[0082] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for assessing the health status of a clutch under creeping operating conditions based on digital twins, characterized in that, include: Acquire real vehicle operation data and construct a clutch twin. Input the real vehicle operation data into the clutch twin to identify the real vehicle creeping condition. If the real vehicle operation data meets the preset conditions, activate the real vehicle creeping function, control the creeping speed, and calculate the creeping friction work. The creeping friction work is compared with the safe friction work threshold, and the health status of the clutch is evaluated by the comparison result. Based on the health status evaluation result, a health management strategy is implemented for the clutch. Assessing the health condition of the clutch includes: The relative error between the creeping friction work and the safe creeping friction work threshold is compared to assess the health status of the clutch entity. If the relative error is less than or equal to a first preset value, the constant speed creeping continues. If the relative error is greater than the first preset value but less than or equal to a second preset value, intervention is performed through the clutch twin. If the relative error is greater than the second preset value, driver intervention is required, as shown in the following formula: ； b ≤70%, the clutch body is within a safe range, and constant speed creeping can continue; 70% < b ≤85% indicates the clutch body is in a dangerous range, requiring intervention from the clutch twin. The clutch twin sends a signal to the vehicle body to adjust the clutch body's lubrication flow to its maximum value and increase the clutch body's forced cooling power. Q ( q ); b If the clutch is more than 85% compliant, the clutch unit is in a dangerous range and driver intervention is required. The clutch twin sends a signal to the vehicle unit to adjust the clutch unit lubrication flow to the maximum value. An alarm dialog box pops up on the vehicle unit display screen, prompting the driver to release the brake pedal. The relative error is: In the formula, This represents the relative error between the creeping friction work and the safe friction work threshold. This is a peristaltic, rubbing motion. The threshold for safe friction work.

2. The method for assessing the health status of a clutch under creeping conditions based on digital twins according to claim 1, characterized in that, The preset conditions are: In the formula, v For real-time vehicle speed, a To accelerate the vehicle, α This represents the brake pedal opening value. β This represents the throttle opening value.

3. The method for assessing the health status of a clutch under creeping operating conditions based on digital twins according to claim 1, characterized in that, Controlling the creeping speed based on a creeping control strategy includes: The target vehicle speed of the clutch twin is set as follows: vx The vehicle's actual speed v and the target speed vx deviation Δ v The input is the pressure of the physical friction pair of the clutch, the output is the pressure of the clutch body friction pair, and the control target is Δ. v When the speed approaches 0, the vehicle moves stably, and the speed of the clutch's driving end increases. n 1 is greater than the passive end speed n 2.

4. The method for assessing the health status of a clutch under creeping operating conditions based on digital twins according to claim 3, characterized in that, The creep control strategy is as follows: In the formula, F The pressure of the clutch physical friction pair, λ 1. λ 2. λ3 represents the proportional constant, integral constant, and derivative constant of the PID controller, respectively. For time.

5. The method for assessing the health status of a clutch under creeping operating conditions based on digital twins according to claim 1, characterized in that, The method for calculating the creeping friction work is as follows: In the formula, μ The coefficient of friction, r e is the radius of the frictional side effect. K n is the clamping force reduction coefficient, and Z is the number of friction pairs; Q ( q (This refers to the forced cooling power of the clutch.) q For lubrication flow, For frictional torque, F The pressure of the clutch physical friction pair, The angular velocity of the clutch driving end. The angular velocity of the driven end of the clutch. This is a peristaltic, rubbing motion. n 1 represents the rotational speed of the driving end of the clutch. n 2 represents the rotational speed of the driven end of the clutch.

6. The method for assessing the health status of a clutch under creeping operating conditions based on digital twins according to claim 5, characterized in that, The safe friction energy threshold is: In the formula, The friction torque threshold, p For the clutch body to engage properly, the hydraulic pressure is required. A The contact area of ​​the friction pair, n 0 represents the stable speed of the clutch body under long-term slip friction. t 0 represents the allowable extended slippage time of the clutch body. This is the difference in maximum angular acceleration of the clutch. The threshold for safe friction work.

7. The method for assessing the health status of a clutch under creeping operating conditions based on digital twins according to claim 1, characterized in that, The method further includes performing limp detection, wherein when the driver releases the pedal, the clutch twin continuously calculates the creep friction work W, and when the relative error... At this time, the clutch twin sends a signal to the vehicle body to adjust the lubrication flow of the clutch body to the normal value and restarts the crawl recognition, prompting the driver to continue to execute the crawl mode.

8. A clutch creep condition health status assessment system based on digital twins, used to implement the clutch creep condition health status assessment method based on digital twins as described in any one of claims 1-7, characterized in that, include: Data acquisition and transmission unit: used to collect sensor data of the vehicle entity, transmit the sensor data of the vehicle entity to the clutch twin, and send the twin data and instructions of the clutch twin to the vehicle entity; Clutch digital twin unit: used to construct a clutch twin based on the operating status of the clutch entity, and to transmit the sensor data of the vehicle entity to the clutch twin wirelessly; Crawl identification unit: used to identify the crawling condition of the vehicle entity based on the vehicle entity data received by the clutch twin, and activate the real vehicle crawling function; Crawl speed control unit: used to send instructions to the vehicle entity through the data acquisition and transmission unit to execute the crawl control strategy; Slip friction work calculation unit: Used to calculate the clutch creep slip friction work after the clutch twin is activated in creep mode. W and safety friction threshold W0 ; Health status assessment unit: used to assess the health status of the clutch entity by measuring the relative error between the creeping friction work and the safe friction work threshold; The assessment of the clutch's health status includes: The relative error between the creeping friction work and the safe creeping friction work threshold is compared to assess the health status of the clutch entity. If the relative error is less than or equal to a first preset value, the constant speed creeping continues. If the relative error is greater than the first preset value but less than or equal to a second preset value, intervention is performed through the clutch twin. If the relative error is greater than the second preset value, driver intervention is required, as shown in the following formula: ； b ≤70%, the clutch body is within a safe range, and constant speed creeping can continue; 70% < b ≤85% indicates the clutch body is in a dangerous range, requiring intervention from the clutch twin. The clutch twin sends a signal to the vehicle body to adjust the clutch body's lubrication flow to its maximum value and increase the clutch body's forced cooling power. Q ( q ); b If the clutch is more than 85% compliant, the clutch unit is in a dangerous range and driver intervention is required. The clutch twin sends a signal to the vehicle unit to adjust the clutch unit lubrication flow to the maximum value. An alarm dialog box pops up on the vehicle unit display screen, prompting the driver to release the brake pedal. The relative error is: In the formula, This represents the relative error between the creeping friction work and the safe friction work threshold. This is a peristaltic, rubbing motion. The threshold for safe friction work; Health management unit: Used to manage health based on the results of health status assessment; Limp detection unit: Used to monitor the limpness of the vehicle body. When the clutch body meets the health management requirements, the clutch twin re-engages the crawl recognition and prompts the driver to continue to execute the crawl mode.

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