Terminal post bolt loosening detection method, device, equipment and readable storage medium

Abstract

The application discloses a kind of terminal post bolt loosening detection method, device, equipment and readable storage medium, it is related to new energy automobile motor technical field, comprising: the current speed of vehicle driving motor is obtained, the current state of vehicle is judged according to the current speed of vehicle driving motor;When the current state of vehicle is stationary state, detection signal is injected to vehicle driving motor, the impedance angle of motor phase winding is calculated according to the detection signal and the feedback signal of acquisition, whether the terminal post bolt of vehicle driving motor is loosened according to the impedance angle of motor phase winding calculated;When the current state of vehicle is running state, the motor current unbalance degree is calculated according to the three-phase current of vehicle driving motor, and whether the terminal post bolt of vehicle driving motor is loosened according to the motor current unbalance degree calculated.The application judges whether the terminal post bolt loosens in the stationary, running state of vehicle, realizes low cost, high reliability on-line detection.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle motor technology, and in particular to a method, apparatus, equipment, and readable storage medium for detecting loose terminal bolts. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the drive motor, as a core component of the vehicle's power system, is of paramount importance in terms of operational safety and reliability. The terminal bolts of the drive motor, used to connect the motor windings to the external high-voltage harness, are critical nodes for high-voltage current transmission. During long-term vehicle operation, factors such as vibration and thermal cycling can cause these terminal bolts to loosen, leading to increased resistance at the contact points. When a large current passes through these loose points, abnormal heating can occur, potentially causing overheating, arcing, or even fire, threatening the intrinsic safety of the vehicle's high-voltage system.

[0003] In existing technologies, the detection of loose terminal bolts mainly relies on periodic manual inspections or specific online monitoring solutions. Manual inspections require the vehicle to be stopped and operated by professionals, making real-time monitoring impossible. Some online monitoring solutions indirectly determine the connection status by installing additional dedicated vibration or temperature sensors, or require modifications to the existing structural design and assembly process of the motor to adapt to the detection device.

[0004] However, the aforementioned existing technologies have significant drawbacks. On the one hand, manual inspection is not timely and cannot detect potential problems in the early stages of loosening, creating safety blind spots. On the other hand, adding dedicated sensors significantly increases hardware costs and system complexity, and modifying existing structures and assembly processes is difficult and not conducive to mass production integration. Therefore, how to achieve real-time, reliable, and low-cost online detection of loose terminal bolts without altering the existing structure and assembly process of new energy vehicle drive motors has become a pressing technical problem for those skilled in the art. Summary of the Invention

[0005] This invention provides a method, apparatus, device, and readable storage medium for detecting loose terminal bolts, in order to solve the technical problem of how to achieve real-time, reliable, and low-cost online detection of the loose state of terminal bolts without changing the existing structure and assembly process of the drive motor of new energy vehicles.

[0006] Firstly, a method for detecting loose terminal bolts is provided, including the following steps: Obtain the current speed of the vehicle drive motor, and determine the current state of the vehicle based on the current speed of the vehicle drive motor; When the vehicle is currently stationary, a detection signal is injected into the vehicle drive motor. The impedance angle of the motor phase winding is calculated based on the injected detection signal and the collected feedback signal. The calculated impedance angle of the motor phase winding is used to determine whether the terminal bolts of the vehicle drive motor are loose. When the vehicle is currently in operation, the motor current imbalance is calculated based on the three-phase current of the vehicle drive motor, and then the looseness of the terminal bolts of the vehicle drive motor is determined based on the calculated motor current imbalance.

[0007] In some embodiments, when the vehicle is currently stationary, injecting a detection signal into the vehicle drive motor and calculating the motor phase winding impedance angle based on the injected detection signal and the collected feedback signal includes: The switching unit in the inverter corresponding to the vehicle drive motor is controlled to operate, and the output current signal is injected into the vehicle drive motor as a detection signal.

[0008] In some embodiments, the switching unit in the drive motor inverter corresponding to the controlled vehicle drive motor operates, and the output current signal is injected into the vehicle drive motor as a detection signal, including: Control the operation of the switching unit in the drive motor inverter corresponding to the vehicle drive motor, and inject a current signal between at least any two phase windings of the vehicle drive motor.

[0009] In some embodiments, the switching unit in the drive motor inverter corresponding to the vehicle drive motor is activated, and the output current signal is injected into the vehicle drive motor as a detection signal, further comprising: Adjust the frequency of the output current signal and inject current signals of different frequencies into the vehicle drive motor.

[0010] In some embodiments, determining whether the terminal bolts of the vehicle drive motor are loose based on the calculated motor phase winding impedance angle includes: Obtain the reference impedance angle of the vehicle drive motor in the unclogged state; Determine whether the absolute value of the difference between the calculated motor phase winding impedance angle and the motor reference impedance angle exceeds the preset difference threshold. If yes, it is determined that the terminal bolts of the vehicle drive motor are loose; if no, it is determined that the terminal bolts of the vehicle drive motor are not loose.

[0011] In some embodiments, the step of calculating the motor current imbalance based on the three-phase current of the vehicle drive motor when the vehicle's current state is running includes: Calculate the average current of the three-phase current of the vehicle drive motor, and then calculate the motor current imbalance based on the difference between the maximum and minimum currents of the three-phase current of the vehicle drive motor and the average current.

[0012] In some embodiments, the step of determining whether the terminal bolts of the vehicle drive motor are loose based on the calculated motor current imbalance includes: The calculated motor current imbalance is compared with the preset motor current imbalance threshold. If the calculated motor current imbalance exceeds the preset motor current imbalance threshold, it is determined that the terminal bolts of the vehicle drive motor are loose.

[0013] Secondly, a device for detecting loose terminal bolts is provided, comprising: The first judgment unit is used to obtain the current speed of the vehicle drive motor and judge the current state of the vehicle based on the current speed of the vehicle drive motor. The second judgment unit is used to inject a detection signal into the vehicle drive motor when the current state of the vehicle is stationary, calculate the impedance angle of the motor phase winding based on the injected detection signal and the collected feedback signal, and determine whether the terminal bolts of the vehicle drive motor are loose based on the calculated impedance angle of the motor phase winding. The third judgment unit is used to calculate the motor current imbalance based on the three-phase current of the vehicle drive motor when the vehicle is currently in operation, and then determine whether the terminal bolts of the vehicle drive motor are loose based on the calculated motor current imbalance.

[0014] Thirdly, a computer device is provided, comprising: a memory and a processor, wherein the memory stores at least one instruction, the at least one instruction being loaded and executed by the processor to implement the aforementioned method for detecting loose terminal bolts.

[0015] Fourthly, a computer-readable storage medium is provided, the computer-readable storage medium storing computer instructions, which, when executed by a computer, cause the computer to perform the aforementioned method for detecting loose terminal bolts.

[0016] The beneficial effects of the technical solution provided by this invention include: 1. Reduced hardware costs and system complexity: No need to install additional dedicated sensors, significantly reducing hardware costs and system complexity.

[0017] 2. Achieve early warning and improve safety level: It can trigger an early warning in the early stage of bolt loosening, effectively avoiding serious safety accidents such as overheating, electric arc or even fire caused by poor contact, and significantly improving the inherent safety level of the vehicle's high-voltage system.

[0018] 3. Easy to integrate and mass-produce: It can be seamlessly integrated into the existing motor control architecture, is compatible with mainstream permanent magnet synchronous motor platforms, supports real-time diagnosis and fault reporting, and is easy to implement safety strategies in conjunction with the vehicle controller. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic flowchart illustrating a method for detecting loose terminal bolts provided in an embodiment of the present invention; Figure 2 A schematic diagram of a drive motor inverter and a drive motor provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the phase winding resistance and inductance of a drive motor with symmetrical three-phase windings, provided in an embodiment of the present invention. Figure 4 This is a schematic diagram showing the resistance and inductance of the A-phase winding terminal bolt of the drive motor after it has been loosened, according to an embodiment of the present invention. Figure 5 This is a schematic diagram of the current conduction paths of phase A and phase B provided in an embodiment of the present invention; Figure 6 A schematic diagram of the impedance angle of a motor phase winding provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of a terminal bolt loosening detection device provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of a computer device provided in an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] This invention provides a method for detecting loose terminal bolts, which solves the technical problem of how to achieve real-time, reliable, and low-cost online detection of the loose state of terminal bolts without changing the existing structure and assembly process of the drive motor of new energy vehicles.

[0023] See Figure 1 This invention provides a method for detecting loose terminal bolts, comprising the following steps: Step S1: Obtain the current speed of the vehicle drive motor and determine the current state of the vehicle based on the current speed of the vehicle drive motor. The vehicle state is mainly divided into a stationary state and a running state. The stationary state refers to the state where the vehicle has not started and the motor has not rotated (e.g., before the vehicle is powered on but not engaged in gear). The running state refers to the state where the vehicle has started and the motor is driving the wheels to rotate.

[0024] Step S2: When the vehicle is currently stationary, a detection signal is injected into the vehicle drive motor. The impedance angle of the motor phase winding is calculated based on the injected detection signal and the collected feedback signal. The connection bolts of the vehicle drive motor are then determined to be loose based on the calculated impedance angle of the motor phase winding.

[0025] Specifically, when the vehicle is currently stationary, injecting a detection signal into the vehicle drive motor and calculating the motor phase winding impedance angle based on the injected detection signal and the collected feedback signal includes: The switching unit in the inverter corresponding to the vehicle drive motor is controlled to operate, and the output current signal is injected into the vehicle drive motor as a detection signal.

[0026] Furthermore, the switching unit in the drive motor inverter corresponding to the controlled vehicle drive motor operates, and the output current signal is injected into the vehicle drive motor as a detection signal, including: Control the operation of the switching unit in the drive motor inverter corresponding to the vehicle drive motor, and inject a current signal between at least any two phase windings of the vehicle drive motor.

[0027] The specific implementation process is as follows: Control the operation of the switching unit in the inverter corresponding to the drive motor, such as... Figure 2 As shown, the drive motor inverter contains multiple switching units (V1-V6), and specific switching units are controlled to conduct to form a current loop.

[0028] Figure 3 This is an impedance model for the resistance and inductance of a drive motor. Each phase winding of the drive motor contains a phase resistance and a phase inductance connected in series, and the resistances and inductances in the three phase windings of the drive motor are symmetrical. When the terminal bolts of the vehicle drive motor become loose, such as at the terminal of phase A winding, the loose bolt will cause the resistance value of the motor phase winding to increase, which is equivalent to an external resistance being connected in series in phase A winding. It has no effect on the inductance of the phase winding. Figure 4 This is a schematic diagram showing the resistance and inductance of the A-phase winding terminal bolts of a vehicle drive motor after they have become loose.

[0029] For example, when the vehicle is currently stationary (before it starts), control switches V1 and V6 are turned on, allowing current to flow through phases A and B, while phase C has no current. Assuming a loose connection at the phase A terminal, the inverter controlling the drive motor outputs a high-frequency current signal ( This current signal, with a preset amplitude, is injected into the drive motor as a detection signal. and frequency Assume the resistance of each phase winding is... The phase winding inductance is The contact resistance after the bolt is loosened is Therefore, under high-frequency current, the reactance corresponding to the inductance of the phase winding coil is... The conduction path of the current is as follows Figure 5 As shown.

[0030] Collect the voltage at the terminals of phase A and phase B. (i.e., feedback signal), based on the collected voltages at the terminals of phases A and B. and injected high-frequency current Obtain the phase winding impedance angle Specifically, this can be achieved by calculating the voltage at the terminals of phase A and phase B. High frequency current Phase difference yields phase winding impedance angle Furthermore, the voltage equation for the entire circuit is: ,Right now ,like Figure 6 As shown, the phase winding impedance angle can also be adopted. This means that the impedance angle of the phase winding can be known. Subject to contact resistance of The impact.

[0031] Furthermore, the step of determining whether the terminal bolts of the vehicle drive motor are loose based on the calculated motor phase winding impedance angle includes: Obtain the reference impedance angle of the vehicle drive motor in the unclogged state; Determine whether the absolute value of the difference between the calculated motor phase winding impedance angle and the motor reference impedance angle exceeds the preset difference threshold. If yes, it is determined that the terminal bolts of the vehicle drive motor are loose; if no, it is determined that the terminal bolts of the vehicle drive motor are not loose.

[0032] Loose bolts will cause the resistance of the motor phase winding to increase, which is equivalent to an external contact resistance being introduced into the winding. Under the same high-frequency current excitation, the resulting impedance angle will change.

[0033] If the bolts on the terminals do not loosen after a high-frequency current is injected, then At this point, the impedance angle is obtained. This serves as the reference impedance angle; contact resistance is generated when the bolts on the terminals become loose. ( Then, under the same high-frequency current excitation, the resulting impedance angle is... ;like This indicates that the terminal block is loose.

[0034] Because the phase winding resistance of the drive motor is very small, the contact resistance of the external terminals is related to the looseness of the bolts. Simply calculating the resistance will produce a large error. In this embodiment of the invention, a high-frequency current is injected to analyze the change in the impedance angle of the motor phase winding to determine the resistance change, which is indirectly reflected by other electrical parameter characteristics.

[0035] In addition, the same detection process is applied to the phases A and C, as well as the phases B and C, to improve the comprehensiveness of the detection.

[0036] Step S3: When the vehicle is currently in operation, calculate the motor current imbalance based on the three-phase current of the vehicle drive motor, and then determine whether the terminal bolts of the vehicle drive motor are loose based on the calculated motor current imbalance.

[0037] To further reduce the impact of external interference during the analysis of the motor phase winding impedance angle and more accurately identify loose terminals, the unbalance of the three-phase current of the drive motor can be further checked after the vehicle is started. In a three-phase permanent magnet synchronous motor system, the three-phase current imbalance is an important indicator reflecting the motor's health, controller performance, and power supply quality. Slight imbalance may originate from parameter deviations or load disturbances, while significant imbalance often indicates winding faults (such as inter-turn short circuits), abnormal power devices in the drive motor inverter, current sensor drift, or loose wiring.

[0038] Specifically, when the vehicle is currently in operation, calculating the motor current imbalance based on the three-phase current of the vehicle drive motor includes: Calculate the average current of the three-phase current of the vehicle drive motor, and then calculate the motor current imbalance based on the difference between the maximum and minimum currents of the three-phase current of the vehicle drive motor and the average current.

[0039] When a motor is running under heavy load, the current in the phase winding is generally large, and the resistance in the winding will also increase with the temperature. When the motor terminals become loose, the asymmetry of the phase winding resistance will be indirectly reflected in the phase winding current. Therefore, by detecting the imbalance of the three-phase current, the looseness of the motor terminals can be indirectly reflected.

[0040] Calculate the average current: ;in, , , are three-phase currents. The three-phase currents can be subjected to signal conversion by a current sensor, and then obtained after signal conditioning (filtering, amplification, biasing) and analog-to-digital conversion (ADC); Current imbalance: .

[0041] Furthermore, judging whether the terminal bolts of the vehicle drive motor are loose according to the calculated motor current imbalance includes: Comparing the calculated motor current imbalance with a preset motor current imbalance threshold; If the calculated motor current imbalance exceeds the preset motor current imbalance threshold, it is determined that the terminal bolts of the vehicle drive motor are loose.

[0042] Among them, the preset motor current imbalance threshold can be set in grades: Normal condition: The calculated motor current imbalance < 2% - 5%; Warning state: The calculated motor current imbalance is between 5% - 10%, and a warning signal is generated; Fault state: The calculated motor current imbalance > 10%, it is determined that the terminal bolts are loose, and a fault signal is generated.

[0043] It should be noted that the embodiment of the present invention can also generate a looseness detection signal according to the above judgment results in the static state and / or the running state. When a signal indicating that the terminal bolts of the drive motor are loose is obtained, control protection is performed on the drive motor controller (including the drive motor inverter).

[0044] In the terminal bolt looseness detection method in the embodiment of the present invention, by respectively analyzing the change of the phase winding impedance angle and the three-phase current imbalance during the static state and the running state of the vehicle, it is further judged whether the terminal bolts are loose. First, this method does not require additional installation of special sensors, achieving online detection with low cost and high reliability. Second, compared with the traditional lagging means relying on temperature rise alarm or manual inspection, this method can trigger an early warning at the initial stage of bolt looseness, effectively avoiding serious safety accidents such as overheating, electric arc, and even fire caused by poor contact, and significantly improving the intrinsic safety level of the vehicle's high-voltage system. Finally, this method can be seamlessly integrated into the existing motor control architecture, compatible with mainstream permanent magnet synchronous motor platforms, supporting real-time diagnosis and fault reporting, and facilitating the implementation of safety strategies in联动 with the vehicle controller.

[0045] In an optional embodiment, controlling the switch unit in the drive motor inverter corresponding to the drive motor to act, and outputting a current signal as a detection signal to be injected into the drive motor, further includes: Adjust the frequency of the output current signal, and inject current signals of different frequencies into the drive motor.

[0046] In the embodiment of the present invention, to avoid interference from external signals, the frequency of the injected current can be adjusted, and current signals of different frequencies are injected into the drive motor for multiple groups of state detection and analysis.

[0047] See Figure 7 As shown, the embodiment of the present invention also provides a wiring terminal bolt loosening detection device, including: a first judgment unit, a second judgment unit, and a third judgment unit.

[0048] The first judgment unit is used to obtain the current speed of the vehicle drive motor and judge the current state of the vehicle according to the current speed of the vehicle drive motor.

[0049] The second judgment unit is used to inject a detection signal into the vehicle drive motor when the current state of the vehicle is a stationary state, calculate the impedance angle of the motor phase winding according to the injected detection signal and the collected feedback signal, and judge whether the wiring terminal bolt of the vehicle drive motor is loose according to the calculated impedance angle of the motor phase winding.

[0050] The third judgment unit is used to calculate the motor current imbalance degree according to the three-phase current of the vehicle drive motor when the current state of the vehicle is a running state, and then judge whether the wiring terminal bolt of the vehicle drive motor is loose according to the calculated motor current imbalance degree.

[0051] In the wiring terminal bolt loosening detection device in the embodiment of the present invention, by analyzing the change of the impedance angle of the phase winding and the three-phase current imbalance degree during the stationary state and running state of the vehicle, it is further judged whether the wiring terminal bolt is loose. First, the device does not require additional installation of special sensors, achieving online detection with low cost and high reliability. Second, compared with the traditional lagging means relying on temperature rise alarm or manual inspection, the device can trigger an early warning at the initial stage of bolt loosening, effectively avoiding serious safety accidents such as overheating, electric arc, and even fire caused by poor contact, and significantly improving the intrinsic safety level of the vehicle's high-voltage system. Finally, the device can be seamlessly integrated into the existing motor control architecture, compatible with mainstream permanent magnet synchronous motor platforms, support real-time diagnosis and fault reporting, and facilitate the implementation of safety strategies in linkage with the vehicle controller.

[0052] The embodiment of the present invention also provides a computer device, including: a memory, a processor, and a network interface connected through a system bus. At least one instruction is stored in the memory, and at least one instruction is loaded and executed by the processor to implement all or part of the steps of the foregoing wiring terminal bolt loosening detection method.

[0053] Among them, the network interface is used for network communication, such as sending assigned tasks, etc. Those skilled in the art can understand, Figure 8 The structure shown is merely a block diagram of a portion of the structure related to the present invention and does not constitute a limitation on the computer device to which the present invention is applied. A specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0054] A processor can be a CPU, or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. A general-purpose processor can be a microprocessor, or any conventional processor. The processor is the control center of a computer device, connecting all parts of the computer device through various interfaces and lines.

[0055] Memory can be used to store computer programs and / or modules. The processor implements various functions of a computer device by running or executing the computer programs and / or modules stored in the memory, and by accessing data stored in the memory. Memory can mainly include a program storage area and a data storage area. The program storage area can store the operating system, application programs required for at least one function (such as video playback, image playback, etc.), etc.; the data storage area can store data created using the memory (such as video data, image data, etc.). Furthermore, memory can include high-speed random access memory (RAM), and can also include non-volatile memory, such as hard disks, RAM, plug-in hard disks, smart media cards (SMC), secure digital (SD) cards, flash cards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0056] This invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements all or part of the steps of the aforementioned method for detecting loose terminal bolts.

[0057] The embodiments of the present invention can implement all or part of the aforementioned processes, or they can be accomplished by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various methods described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added to or subtracted according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0058] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, servers, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0059] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0060] The serial numbers in the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0061] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0062] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A terminal post bolt loosening detection method characterized by, Includes the following steps: Obtain the current speed of the vehicle drive motor, and determine the current state of the vehicle based on the current speed of the vehicle drive motor; When the vehicle is currently stationary, a detection signal is injected into the vehicle drive motor. The impedance angle of the motor phase winding is calculated based on the injected detection signal and the collected feedback signal. The calculated impedance angle of the motor phase winding is used to determine whether the terminal bolts of the vehicle drive motor are loose. When the vehicle is currently in operation, the motor current imbalance is calculated based on the three-phase current of the vehicle drive motor, and then the looseness of the terminal bolts of the vehicle drive motor is determined based on the calculated motor current imbalance.

2. The terminal post looseness detection method according to claim 1, characterized by, When the vehicle is currently stationary, a detection signal is injected into the vehicle drive motor, and the impedance angle of the motor phase winding is calculated based on the injected detection signal and the collected feedback signal, including: The switching unit in the inverter corresponding to the vehicle drive motor is controlled to operate, and the output current signal is injected into the vehicle drive motor as a detection signal.

3. The terminal post looseness detection method according to claim 2, characterized by, The switching unit in the inverter corresponding to the vehicle drive motor is activated, and the output current signal is injected into the vehicle drive motor as a detection signal, including: Control the operation of the switching unit in the drive motor inverter corresponding to the vehicle drive motor, and inject a current signal between at least any two phase windings of the vehicle drive motor.

4. The terminal post looseness detection method according to claim 2, characterized by, The method of controlling the operation of the switching unit in the drive motor inverter corresponding to the vehicle drive motor, and outputting a current signal as a detection signal to inject into the vehicle drive motor, further includes: Adjust the frequency of the output current signal and inject current signals of different frequencies into the vehicle drive motor.

5. The terminal post looseness detection method of claim 1, wherein The step of determining whether the terminal bolts of the vehicle drive motor are loose based on the calculated impedance angle of the motor phase winding includes: Obtain the reference impedance angle of the vehicle drive motor in the unclogged state; Determine whether the absolute value of the difference between the calculated motor phase winding impedance angle and the motor reference impedance angle exceeds the preset difference threshold. If yes, it is determined that the terminal bolts of the vehicle drive motor are loose; if no, it is determined that the terminal bolts of the vehicle drive motor are not loose.

6. The terminal post looseness detection method of claim 1, wherein When the vehicle is currently in operation, the motor current imbalance is calculated based on the three-phase current of the vehicle drive motor, including: Calculate the average current of the three-phase current of the vehicle drive motor, and then calculate the motor current imbalance based on the difference between the maximum and minimum currents of the three-phase current of the vehicle drive motor and the average current.

7. The terminal post looseness detection method of claim 1, wherein The next step, determining whether the terminal bolts of the vehicle drive motor are loose based on the calculated motor current imbalance, includes: The calculated motor current imbalance is compared with the preset motor current imbalance threshold. If the calculated motor current imbalance exceeds the preset motor current imbalance threshold, it is determined that the terminal bolts of the vehicle drive motor are loose.

8. A terminal post bolt loosening detection device characterized by comprising: include: The first judgment unit is used to obtain the current speed of the vehicle drive motor and judge the current state of the vehicle based on the current speed of the vehicle drive motor. The second judgment unit is used to inject a detection signal into the vehicle drive motor when the current state of the vehicle is stationary, calculate the impedance angle of the motor phase winding based on the injected detection signal and the collected feedback signal, and determine whether the terminal bolts of the vehicle drive motor are loose based on the calculated impedance angle of the motor phase winding. The third judgment unit is used to calculate the motor current imbalance based on the three-phase current of the vehicle drive motor when the vehicle is currently in operation, and then determine whether the terminal bolts of the vehicle drive motor are loose based on the calculated motor current imbalance.

9. A computer device, comprising: include: A memory and a processor, wherein the memory stores at least one instruction, which is loaded and executed by the processor to implement the terminal bolt loosening detection method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions that, when executed by a computer, cause the computer to perform the terminal bolt loosening detection method according to any one of claims 1 to 7.

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