Cable bending torsion composite mechanical life test method and test equipment

Abstract

The invention provides a cable bending and torsion composite mechanical life test method and test equipment, and relates to the technical field of cable aging test, and the method comprises the steps: applying a periodic bending load and a torsion load to a to-be-tested cable, setting a target loading path, collecting test data in real time, and determining an execution state; whether the bending load and the torsion load meet the consistency requirement or not is judged, when it is judged that the bending load and the torsion load do not meet the consistency requirement, the current bending load applying process and / or the current torsion load applying process are / is adjusted, and the service life cycle number of the cable reckoned in the current service life test cycle is determined; and the mechanical life of the cable under the action of the bending torsion combined load is obtained. According to the invention, the technical problems of loading path deviation, damage accumulation distortion and inaccurate service life evaluation result caused by asynchronous bending and torsion load application in an actual composite loading test are solved, and the consistency of a composite fatigue loading path and the reliability of a test conclusion are ensured.

Description

Technical Field

[0001] This invention relates to the field of cable aging testing technology, and in particular to a method and testing equipment for testing the combined mechanical life of cable bending and torsion. Background Technology

[0002] As the carrier of electrical energy and signals, accurately assessing the fatigue life of cables under real-world operating conditions is crucial. In practical applications, especially in robot joints and cable chain systems, cables typically withstand both bending and torsional stresses simultaneously. To realistically simulate the operating environment of cables, many testing devices need to be able to apply bending and torsional loads simultaneously to evaluate the fatigue life of cables under combined stress.

[0003] However, in actual cable bending-torsion composite load testing, it is often difficult to achieve perfect synchronization between the bending and torsional loads under ideal conditions. This synchronization error stems from a combination of unavoidable factors at both the mechanical structure and control system levels of the testing equipment. First, components such as gears and couplings in the mechanical structure inevitably experience friction, clearance, and elastic deformation of materials during load transmission. For example, gear meshing clearance can cause a slight timing misalignment between the target displacement and the actual displacement. Second, different drive mechanisms (such as bending motors and torsional motors) have different response speeds and inertial characteristics, making it difficult to maintain perfect consistency in the application time and speed of the load during high-frequency, multi-cycle fatigue testing. Third, the control system itself has problems such as signal transmission delay and limited adjustment bandwidth, further exacerbating the difficulty of load synchronization. For example, the testing equipment is set to ensure that bending and torsion reach their peak values ​​simultaneously at the fifth second within each cycle. However, due to gear clearance or motor response delay, the bending end reaches 2 cm earlier in a certain cycle, while the torsional end lags behind due to inertia, only reaching half of the expected angle. This timing inconsistency causes the composite stress path experienced by the cable to deviate from the set ideal path, leading to deviations in the accumulation of fatigue damage. The presence of synchronization errors not only weakens the repeatability and comparability of test results but also directly affects the accurate assessment of cable fatigue life. Because the multi-layered structure inside the cable is highly sensitive to load synchronization, even small synchronization errors can cause localized strain concentration and changes in interlayer slip rhythm, thereby inducing premature failure or non-target failure modes. These errors gradually accumulate during long-term, high-frequency fatigue testing, especially in multi-cycle processes, and affect the cable's life assessment. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a method and testing equipment for testing the combined mechanical life of cables under bending and torsion, solving the technical problems of asynchronous application of bending and torsional loads in actual combined loading tests, which leads to loading path deviation, damage accumulation distortion, and inaccurate life assessment results. Through online detection and closed-loop compensation of synchronization errors, the consistency of the combined fatigue loading path and the reliability of the test conclusions are ensured.

[0005] This invention provides a method for testing the combined mechanical life of cables under bending and torsion, the method comprising: S1. Under the preset test conditions, apply periodic bending loads and torsional loads to the cable under test based on the test equipment, and set the target loading path corresponding to the bending load and torsional load in each life test cycle. The target loading path includes at least the loading sequence, loading amplitude and loading process.

[0006] S2. During each life test cycle, test data reflecting the bending load state and torsional load state are collected in real time, and the execution state of bending load and torsional load relative to the target loading path is determined based on the test data.

[0007] S3. Based on the execution status, determine whether the bending load and torsional load meet the consistency requirements. If the bending load and torsional load meet the consistency requirements, continue to execute the life test.

[0008] S4. When it is determined that the bending load and torsional load do not meet the consistency requirements, the current bending load application process and / or torsional load application process shall be adjusted so that the bending load and torsional load converge to the target loading path in the subsequent loading process.

[0009] S5. After the current life test cycle ends, evaluate the validity and completeness of the current life test cycle in the life statistics, thereby determining the number of life cycles to be included in the cable's life test cycle.

[0010] S6. Repeat steps S1 to S5 until the cable reaches the preset failure criterion, thereby obtaining the mechanical life of the cable under bending and torsional combined load.

[0011] This application embodiment also provides a cable bending and torsion composite mechanical life testing device, including: The lower turntable, fixed on the equipment base, is driven to rotate by the lower turntable drive motor. It is used to clamp and drive one end of the cable to rotate, thereby applying torsional load to the cable.

[0012] The upper turntable is mounted on a guide rail that can move up and down along the Z-axis and is driven to rotate by an upper turntable drive motor. It is used to clamp the other end of the cable and apply torsional load to the other end of the cable. The upper turntable can be adjusted vertically through the Z-axis drive mechanism, thereby adjusting the distance between the upper and lower turntables to control the bending amplitude of the cable.

[0013] The guide rail is used to support and guide the upper turntable to move precisely up and down along the Z-axis (vertical direction).

[0014] The Z-axis drive mechanism, connected to the upper turntable, enables precise vertical lifting and lowering of the upper turntable, and is used to set and adjust the bending radius or curvature of the cable.

[0015] The clamping system is used to firmly clamp both ends of the cable under test onto the upper and lower turntables respectively using clamps. The clamps can be adapted to different cable diameters and support quick clamping.

[0016] A rotary drive system, including a drive motor that works with the upper and lower turntables, is used to achieve synchronous or differential rotation of the upper and lower turntables in order to apply compound bending and torsional loads in a single cycle.

[0017] The monitoring system, built into a cable bending and torsion composite mechanical life testing device, specifically includes an electrical monitoring module, a force / torque sensor and a cycle counter. It can detect and record the electrical performance parameters, stress conditions and cycle number of the cable in real time during the test, and automatically stop the machine when the parameters are abnormal or the cable fails.

[0018] The control system is built into a cable bending and torsion composite mechanical life testing device. It is used to set test parameters, automatically control the composite loading process, collect and analyze test data, and realize automatic termination and data output linked with life criteria.

[0019] The safety protection system, including protective enclosure, limit switches, and emergency stop buttons, is used to ensure the safety of operators and the testing process.

[0020] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following: 1. This invention provides a method for testing the combined mechanical life of cables under bending and torsion loads. By setting target loading paths for bending and torsional loads in each life test cycle, and collecting and analyzing actual loading data in real time, the method dynamically compares and decomposes progress errors, amplitude errors, and phase errors. It can accurately identify asynchronicity at any moment during the loading process and automatically adjust the application rate and amplitude of bending and torsional loads based on the type and direction of each error when a deviation is detected, ensuring that subsequent loading paths actively converge to the set target. Furthermore, through effectiveness evaluation and recalculation at the end of the cycle, it ensures that even with some invalid loading, the final statistical mechanical life objectively reflects the true fatigue damage of the cable. This improves the accuracy and reliability of test data, reduces human intervention, and enhances the consistency and automation level of combined load fatigue life assessment.

[0021] 2. This invention dynamically determines whether the execution status of bending and torsional loads meets consistency requirements by comparing them in real time during each life test cycle. This allows the testing system to immediately identify invalid loading segments when a loading deviation is detected at any moment, avoiding misjudgments in life statistics caused by abnormal operating conditions. When progress errors, amplitude errors, or phase errors exceed the allowable range, a compensation mechanism is automatically triggered to adjust the subsequent loading process in a timely manner, ensuring the effectiveness of subsequent test cycles. Through this judgment and adjustment process, the probability of damage accumulation due to short-term loss of control or asynchrony being underestimated or overestimated can be reduced, thereby improving the accuracy of each life cycle count and the representativeness of mechanical life data, ensuring that the final evaluation results are more consistent with the damage and failure risks under actual cable service conditions.

[0022] 3. This invention determines the specific number of cable life cycles to be counted in each life test cycle based on the cycle's effectiveness and completeness assessment results after the cycle ends. This makes life statistics no longer simply equivalent to the accumulation of cycle counts, but directly related to the actual loading quality. For life test cycles that fully meet consistency requirements, the life cycle count is directly counted according to the standard cycle, ensuring the continuity of life statistics under normal loading conditions. For life test cycles with inconsistent sampling times, the compensation parameters corresponding to the abnormal times are summarized, the converted count value is calculated, and it is counted in the life cycle count accordingly. This accurately reflects the impact of insufficient or excessive loading on cable fatigue damage in the life statistics results, thereby reducing the life assessment deviation caused by simply ignoring or equating abnormal loading. The final mechanical life value more realistically reflects the actual damage accumulation process of the cable under combined bending and torsional loads.

[0023] 4. This invention provides a cable bending and torsion composite mechanical life testing device, capable of multi-parameter programmable loading of cables under combined bending and torsion. The device uses upper and lower turntables to clamp both ends of the cable, and independent drive motors achieve synchronous or differential rotation of the turntables. Simultaneously, a Z-axis guide rail enables precise vertical lifting and lowering of the upper turntable, allowing flexible setting of the bending radius and torsion angle. During testing, the device automatically monitors the cable's electrical performance (such as insulation resistance and conductor resistance) and mechanical parameters, automatically stopping when an abnormality is detected, avoiding human error and data distortion. Compared to traditional single-loading devices, this device can accurately simulate the stress conditions of cables in complex real-world environments, improving the realism and reliability of mechanical life testing. Attached Figure Description

[0024] Figure 1 This is a flowchart of a cable bending and torsion composite mechanical life test method provided in an embodiment of the present invention; Figure 2 This is a flowchart for determining and counting the effective completeness of life test cycles; Figure 3 This is a circuit connection diagram for real-time cable noise detection; Figure 4 It is a graph showing the change of electrical noise voltage over time during the cable mechanical performance test; Figure 5 This is a schematic diagram of the main interface structure of the host computer control program of the test system involved in this embodiment. Figure 6 This is an interactive confirmation interface diagram after the test control program starts executing; Figure 7 It is a graphical interface that highlights the steps in the test process. Figure 8 This is a diagram of the host computer data acquisition and display interface in an embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of a cable bending and torsion composite mechanical life testing equipment. Figure 1 ; Figure 10 This is a schematic diagram of the structure of a cable bending and torsion composite mechanical life testing equipment. Figure 2 .

[0025] Reference numerals: 1. Lower turntable; 2. Guide rail; 3. Upper turntable. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0027] In the following description, references to "some embodiments" refer to a subset of all possible embodiments; however, it is understood that "some embodiments" may be the same or different subsets of all possible embodiments and may be combined with each other without conflict. This invention provides a method for testing the combined mechanical life of cable bending and torsion, which can be implemented by a cable bending and torsion combined mechanical life testing device, such as... Figure 1 The flowchart shown illustrates a method for testing the combined mechanical life of a cable under bending and torsion loads. The process includes the following steps: Under preset test conditions, periodic bending and torsional loads are applied to the cable under test using testing equipment. Target loading paths are set for the bending and torsional loads in each life test cycle. During each life test cycle, test data reflecting the bending and torsional load states are collected in real time. The execution status of the bending and torsional loads relative to the target loading paths is determined. Whether the bending and torsional loads meet consistency requirements is assessed. If the bending and torsional loads meet the consistency requirements, the life test continues. If the bending and torsional loads do not meet the consistency requirements, the current bending load application process and / or torsional load application process is adjusted. After the current life test cycle ends, the validity and completeness of the current life test cycle in life statistics are evaluated. This determines the number of life cycles to be included in the cable's life cycle count. The cable life test cycle is repeated until the cable reaches the preset failure criterion, thereby obtaining the mechanical life of the cable under combined bending and torsional loads.

[0028] Embodiment 1 of this invention: Taking a low-frequency signal cable as an example, the tester sets the test condition parameters according to the experimental requirements. These parameters include at least environmental conditions (such as laboratory temperature and humidity) and loading frequency. The tester can input the target ambient temperature and humidity range into the equipment control system and set the loading frequency for each cycle to ensure that the experimental conditions match the actual application scenario. Based on the structure and application requirements of the cable under test, the target loading amplitude (such as bending angle or curvature, torsion angle), loading process (i.e., the amount of load change per unit time), and loading sequence (i.e., the synchronization method or timing difference of bending and torsion actions) for bending and torsional loads are set respectively. Combined with actual test requirements, the above parameters are used to generate a target loading path parameter set. The target loading path parameter set can be specifically represented as a set of time series data, clearly defining the bending and torsional load states to be applied at each moment within each test cycle. After completing the parameter settings, the test equipment enters the initialization phase. First, both ends of the cable under test are installed on the upper and lower clamps of the equipment, and adjustments are made to the clamping positions, clamping force, and centering to ensure that the cable is securely installed and the initial stress state is accurate. The key components of the equipment are calibrated, including fixture zero-point reset and sensor verification, to eliminate mechanical errors and initial deviations inherent in the equipment. The generated target loading path parameter set is then imported into the automatic control system of the test equipment. The control system can automatically adjust the drive motor and servo mechanism according to the target path to achieve synchronous or staggered loading of bending and torsional loads, ensuring that the cable is subjected to combined mechanical loads along the set path in each life test cycle.

[0029] Before the formal testing begins, the testing equipment can be automatically or manually triggered to detect system errors and confirm that the loading mechanism, sensors, and data acquisition system are functioning properly. Test personnel can choose to execute 1-2 no-load or low-load simulation cycles to check the accuracy, synchronization, and stability of the monitoring data. After the system detects no abnormalities, the equipment enters the formal life test cycle phase, continuously executing the set composite load and data acquisition until the cable reaches the preset failure criteria.

[0030] During the life test cycle, the monitoring system collects actual state data of bending load and torsional load according to a preset sampling period, including the loading progress value of the actual bending load, the loading progress value of the actual torsional load, the amplitude of the actual bending load, and the amplitude of the actual torsional load at each sampling time, and adds a timestamp to each sampled data. The system obtains a template bending load time series composed of the target bending load progress value and the target bending load amplitude at each sampling time, and a target torsional load time series composed of the target torsional load progress value and the target torsional load amplitude at each sampling time. For each sampling time, the following steps are performed: The loading progress value of the actual bending load at that sampling time (preferably displacement in this example) is subtracted from the target bending load progress value at that time to obtain the bending progress error value. The loading progress value of the actual torsional load at that sampling time is subtracted from the target torsional load progress value at that time to obtain the torsional progress error value. The bending amplitude error is obtained by subtracting the target bending load amplitude from the actual bending load amplitude at the sampling time, and the torsional amplitude error is obtained by subtracting the target torsional load amplitude from the actual torsional load amplitude at the sampling time. Based on the time series data of the bending and torsional loads, the relative time difference between the two at the sampling time is calculated, that is, the difference between the time when the actual bending load reaches a certain loading characteristic point and the time when the actual torsional load reaches the corresponding loading characteristic point. This difference is used as the phase error value at that time. In this example, the difference in timestamps of the corresponding characteristic values ​​can be used to characterize this. The bending progress error value, torsional progress error value, bending amplitude error value, torsional amplitude error value, and phase error value at all sampling times are unified as the execution status data of the bending load and torsional load relative to the target loading path within this life test cycle, and used for subsequent consistency judgment and compensation adjustment.

[0031] If the bending progress error at a certain sampling time exceeds the preset allowable range of bending progress error in the database, it indicates that the actual loading progress of the bending load is significantly ahead or behind the target loading progress. That is, the bending load fails to advance according to the predetermined time rhythm, reflecting that the bending drive has a loading speed deviation or response lag at that moment. Then, the current sampling time is recorded as the bending progress abnormal moment.

[0032] If the torsional progress error exceeds the preset torsional progress error allowable range in the database at a certain sampling time, it indicates that the actual loading progress of the torsional load has a significant deviation from the target loading progress. This means that the torsional loading is not executed according to the predetermined loading rhythm at that time, which may be due to the driving response delay or control error causing the loading process to mismatch. In this case, the current sampling time is recorded as the torsional progress abnormal time.

[0033] If the bending amplitude error at a certain sampling moment exceeds the preset allowable range of bending amplitude error in the database, it indicates that there is a significant deviation between the actual loading amplitude and the target amplitude of the bending load at that moment, that is, the actual bending degree is too large or too small, indicating that the bending loading strength has failed to accurately reach the expected target. In this case, the current sampling moment is recorded as the bending amplitude abnormal moment.

[0034] If the torsional amplitude error at a certain sampling time exceeds the preset torsional amplitude error allowable range in the database, it indicates that the actual torsional amplitude of the torsional load at that time deviates from the target setting, and the actual torsional degree is inconsistent with the target loading requirements, reflecting that the applied torsional load intensity is insufficient or excessive. In this case, the current sampling time is recorded as the torsional amplitude abnormal time.

[0035] If the phase error exceeds the preset phase error allowable range in the database at a certain sampling time, it means that the loading timing relationship between the bending load and the torsional load at that time deviates from the target synchronization relationship. That is, the relative loading positions of the two on the time axis are misaligned, and they fail to maintain the expected synchronous or differential coordination state, which leads to the deviation of the composite loading path. The current sampling time is then recorded as the phase abnormal time.

[0036] Check if the current sampling time is marked as any of the above-mentioned abnormal times. If any abnormality exists, it is determined that the bending load and torsional load at this sampling time do not meet the consistency requirements, triggering corresponding adjustment or compensation measures. If none of the abnormalities exist, it is determined that the bending load and torsional load at the current sampling time meet the consistency requirements, and the life test continues according to the established procedure.

[0037] After detecting that the bending load and torsional load do not meet the consistency requirements at a certain sampling moment, the bending progress error deviation value is calculated based on the difference between the bending progress error value at that moment and the boundary of its allowable interval. Similarly, the torsional progress error deviation value, bending amplitude error deviation value, and torsional amplitude error deviation value are calculated separately, specifically using the distance between the actual error value and the nearest boundary of the corresponding allowable interval as the deviation value.

[0038] If a certain error is within its corresponding error allowable range, the calculated error deviation value is set to zero.

[0039] Using the aforementioned error deviation values ​​as query conditions, the bending drive rate adjustment value, torsional drive rate adjustment value, bending loading amplitude adjustment value, and torsional loading amplitude adjustment value are respectively searched and determined in the preset parameter lookup tables in the database. Specifically, when the bending progress error deviation value is positive, it indicates that the current actual bending progress is lagging behind the target progress, and measures need to be taken to increase the loading speed of the bending load so that it can gradually catch up with and approach the target loading path in the subsequent loading process. In this case, by searching the preset parameter lookup tables in the database, a bending drive rate adjustment value with a positive value suitable for the current deviation level can be obtained. After this adjustment, the bending drive can advance faster, narrowing the gap between the actual loading progress and the target value. Conversely, when the bending progress error deviation value is negative, it means that the current actual bending progress has exceeded the target progress, indicating that the loading is too fast. At this time, it is necessary to appropriately reduce the driving rate of the bending load to slow down the subsequent loading progress, so that the actual progress returns to the vicinity of the target path, that is, to obtain a bending drive rate adjustment value with a negative value suitable for the current deviation level.

[0040] When the torsional progress error deviation is positive, it indicates that the current actual torsional load progress is lagging behind the target progress. The loading speed of the torsional drive needs to be increased to accelerate the progress and gradually catch up with the target path. This means obtaining a torsional drive rate adjustment value that is positive and suitable for this level of deviation to ensure that the torsional load loading can make up for the progress in a timely manner. If the torsional progress error deviation is negative, it indicates that the actual torsional load loading is too fast and has exceeded the target progress. The torsional drive rate should be appropriately reduced to slow down the subsequent progress and gradually synchronize it with the target. This means obtaining a torsional drive rate adjustment value that is negative and suitable for this level of deviation.

[0041] For the bending amplitude error deviation value, if it is positive, it means that the actual bending amplitude is less than the target amplitude, and the set loading strength has not been reached. The loading amplitude needs to be increased. This means obtaining a bending loading amplitude adjustment value that is positive and suitable for this deviation level, so that the bending strength is appropriately increased during subsequent loading processes to keep the actual loading amplitude consistent with the target. Conversely, if the bending amplitude error deviation value is negative, it means that the bending loading amplitude is too large. The loading amplitude should be reduced, and the actual loading amplitude should be decreased through parameter adjustment to prevent excessive force on the cable and unexpected damage. This means obtaining a bending loading amplitude adjustment value that is negative and suitable for this deviation level.

[0042] When the torsional amplitude error deviation is positive, it means that the actual torsional amplitude is lower than the target, and the target amplitude needs to be made up by increasing the loading amplitude. That is, to obtain a torsional loading amplitude adjustment value with a positive value that is suitable for the degree of deviation. If the torsional amplitude error deviation is negative, the actual loading amplitude has exceeded the standard, and the torsional amplitude should be reduced. That is, to obtain a torsional loading amplitude adjustment value with a negative value that is suitable for the degree of deviation.

[0043] Regarding the phase error deviation value, if the phase error deviation value is less than zero, it indicates that the critical moment of bending loading lags behind that of torsional loading, meaning that the two have not achieved the intended synchronization. In this case, the bending drive speed needs to be increased, and the specific increase in bending drive speed can be obtained by consulting the phase-bending mapping table. If the phase error deviation value is greater than zero, it indicates that the torsional load is lagging behind, and the torsional drive speed needs to be increased. The increase in torsional drive speed can be extracted from the phase-torsion mapping table. In this way, the loading processes of the two can be adjusted to a coordinated or synchronized state in a timely manner, ensuring the accuracy of the composite loading path.

[0044] The aforementioned bending drive rate adjustment value, torsion drive rate adjustment value, bending load amplitude adjustment value, torsion load amplitude adjustment value, bending drive speed increase, and torsion drive speed increase are used together as the compensation parameter set for this sampling anomaly and output to the equipment control system in real time to automatically adjust the current bending load application process and / or torsion load application process.

[0045] like Figure 2 The flowchart shown above illustrates the determination and counting process for the validity and completeness of life test cycles. First, the validity and completeness of the cycle are evaluated: if there are no sampling moments where the bending load and torsional load do not meet the consistency requirements, the cycle is determined to be a completely valid cycle and is directly counted as 1 life cycle; if there are sampling moments that do not meet the consistency requirements, the cycle is determined to be incompletely valid, and the actual life count value is calculated through the compensation parameter set and then counted as a life cycle.

[0046] After each life test cycle, the effectiveness and completeness of the cycle must be statistically evaluated. Specifically, the execution status data for all sampling moments within the current life test cycle is retrieved and checked one by one for any sampling moments marked as abnormal bending progress, abnormal torsional progress, abnormal bending amplitude, abnormal torsional amplitude, or abnormal phase. If no inconsistent markers are found in all sampling moments of the cycle, meaning the bending and torsional loads remain within the allowable error range at every moment, then the execution process of the life test cycle is deemed to fully meet the set requirements, and the effectiveness and completeness evaluation result of this cycle is recorded as a fully effective cycle. If any moment during the sampling process of this cycle is recorded as not meeting the consistency requirements (i.e., any abnormal marker appears), it indicates a deviation in the synchronicity or amplitude parameters of the bending or torsional load loading within the life test cycle. Therefore, the cycle is deemed not to have fully followed the preset loading path, and its effectiveness and completeness evaluation result is recorded as an incompletely effective cycle.

[0047] After each life test cycle, the method for counting the current life test cycle into the cable life cycle count is first determined based on the effectiveness and completeness evaluation results within the cycle. Specifically, if no bending or torsional loads fail to meet consistency requirements at any sampling time in the current life cycle, it is considered a fully effective cycle, and this life test cycle is directly counted as one cable life cycle, i.e., the life count is incremented by 1. If any sampling time in the current life test cycle is deemed to fail to meet consistency requirements, this cycle is considered incompletely effective. In this case, it is necessary to further obtain the compensation parameter set corresponding to all abnormal sampling times within this cycle, including bending drive rate adjustment value, torsional drive rate adjustment value, bending load amplitude adjustment value, torsional load amplitude adjustment value, bending drive speed increase, and torsional drive speed increase. The compensation parameters for each abnormal sampling time are summed to obtain the total adjustment value or total increase of each type of parameter. Using the total adjustment values ​​of bending drive rate, torsion drive rate, bending load amplitude, torsion load amplitude, bending drive speed increase, and torsion drive speed increase as indices, the corresponding bending drive first proportional coefficient, torsion drive first proportional coefficient, bending load amplitude proportional coefficient, torsion load amplitude proportional coefficient, bending drive second proportional coefficient, and torsion drive speed second proportional coefficient are obtained from a pre-established parameter lookup table in the database. These proportional coefficients are then multiplied to obtain the converted count value for this life test cycle. This converted count value, in decimal form, reflects the equivalent contribution of the current cycle to the cable life. It serves as the final statistical value for counting the current life test cycle into the cable life cycle count, used for accumulating the total life cycle count and determining subsequent life criteria. This dynamic conversion method more scientifically reflects the true damage contribution of each cycle, ensuring the rationality and accuracy of life assessment.

[0048] It is important to note that when a certain total adjustment value is positive, it indicates that the corresponding loading parameter in this lifespan test cycle is generally on a compensatory upward trend. This means that the actual load is lower than the target path in the early stages of the cycle, and gradually approaches the target loading state through subsequent adjustments. Since the damage to the cable caused by insufficient loading in the early stages is lower than the ideal lifespan cycle, and subsequent compensation only brings the load back to the target level without generating overloading, the cumulative damage to the cable caused by this cycle is less than one standard lifespan cycle. Based on this, a proportional coefficient less than 1 is extracted from the parameter comparison table to recalculate the count for this lifespan test cycle. When a certain total adjustment value is negative, it indicates that the corresponding loading parameter in this lifespan test cycle is generally on a compensatory downward trend. This means that the actual load exceeds the target loading path in the early stages of the cycle, and subsequent adjustments reduce the loading parameter to return to the target state. Since the overloading stage has already caused irreversible additional damage to the cable, even subsequent corrections cannot offset the lifespan loss caused by excessive loading in the early stages. Therefore, the cumulative damage to the cable caused by this lifespan test cycle is greater than one standard lifespan cycle. Based on this, a proportional coefficient greater than 1 is extracted from the parameter comparison table to recalculate the count for this lifespan test cycle.

[0049] If the total value of the bending drive rate adjustment is positive and the larger the value, it indicates that in the current life test cycle, the bending load exhibits a state where the actual loading progress is lower than the target loading progress over many sampling moments or a long period of time. It is necessary to gradually catch up with and approach the target loading path by increasing the bending drive rate multiple times. This situation indicates that in the early stages of this life test cycle, the overall bending load intensity borne by the cable is lower than the ideal loading level, and its cumulative contribution to fatigue damage is relatively insufficient. To reflect the actual situation that this cycle's contribution to cable mechanical damage is less than that of a standard complete cycle in life statistics, the first proportional coefficient of the bending drive rate extracted from the parameter comparison table is between 0 and 1, and gradually decreases as the total value of the bending drive rate adjustment increases. This allows the life test cycle to be included in the cable life cycle count with a weight less than 1 when calculating the count. If the total value of the bending drive rate adjustment is negative and the larger its absolute value, it indicates that in the current life test cycle, the bending load exhibits a state where the actual loading progress exceeds the target loading progress over many sampling moments or a long period of time. It is necessary to correct the loading progress by reducing the bending drive rate multiple times. This situation indicates that in the early stages of this life test cycle, the cable has already been subjected to bending loads exceeding the target loading path, resulting in irreversible fatigue damage, and the overall damage level is higher than the ideal single life cycle. To accurately reflect the additional cost of this excessive loading to the cable's lifespan in life statistics, the first proportional coefficient of the bending drive extracted from the parameter reference table is greater than 1, and gradually increases with the absolute value of the total bending drive rate adjustment. This ensures that this life test cycle is counted in the cable life cycle count with a weight greater than 1 when calculating the total life cycle count.

[0050] If the total value of the torsional drive rate adjustment is positive and the larger the value, it indicates that the actual loading progress of the torsional load in the current life test cycle is lower than the target progress at most sampling moments or over a long period of time, and the torsional drive rate needs to be increased multiple times to compensate. In order to truly reflect the small contribution of insufficient loading in the early stage to cable life damage, the corresponding extracted first proportional coefficient of torsional drive is between 0 and 1 and gradually decreases as the total value increases.

[0051] If the total value of the torsional drive rate adjustment is negative and the larger the absolute value, it indicates that the actual loading progress of the torsional load within the cycle is ahead of schedule, requiring multiple reductions in the drive rate for correction. This suggests that the cable has already experienced excessive torsional load. To reflect this increase in damage, the corresponding extracted first proportional coefficient of the torsional drive is greater than 1 and increases with the increase of the absolute value of the total value.

[0052] If the total value of the bending load amplitude adjustment is positive and the larger the value, the more likely the actual bending load amplitude is below the target value in this cycle. Repeated increases in amplitude compensation result in fatigue damage less than in the standard cycle. To scientifically calculate lifespan, the extracted bending load amplitude proportionality coefficient is between 0 and 1 and decreases as the total value increases. If the total value of the bending load amplitude adjustment is negative and the larger the absolute value, the more likely the actual load amplitude is above the target. Repeated reductions in amplitude correction result in cable damage greater than in the standard cycle. The corresponding bending load amplitude proportionality coefficient is greater than 1 and increases as the absolute value of the total value increases.

[0053] If the total value of the torsional load amplitude adjustment is positive and the larger the value, it indicates that the overall torsional load amplitude is insufficient. After multiple increases in compensation, the actual cable damage is less than the ideal cycle. The corresponding extracted torsional load amplitude proportional coefficient is between 0 and 1 and decreases as the total value increases. If the total value of the torsional load amplitude adjustment is negative and the larger the absolute value, it indicates that the torsional load amplitude is ahead of the curve. After multiple decreases in correction, the damage exceeds the standard cycle. The corresponding extracted torsional load amplitude proportional coefficient is greater than 1 and increases as the absolute value of the total value increases.

[0054] If the total increase in bending drive speed or torsional drive speed is larger, it means that the actual loading is always behind the target path and the cumulative damage is always less than the standard synchronous cycle. Therefore, when performing life conversion, a proportional coefficient of less than 1 is used. That is, the corresponding extracted second proportional coefficient of bending drive or second proportional coefficient of torsional drive speed is between 0 and 1. And as the total increase in drive speed increases, this proportional coefficient further decreases, so that the number of life cycles included in this life test cycle is accumulated according to the conversion value of less than 1.

[0055] To accurately determine the mechanical life of cables under combined bending and torsional loads, an electrical performance test is automatically performed on the cable after each life test cycle. This test includes: real-time measurement and recording of the cable's insulation resistance and conductor resistance values ​​via an electrical testing module. Specific testing can utilize conventional equipment such as high-resistance meters, bridges, and ohmmeters, automatically connected to both ends of the cable according to a preset program, applying a test voltage, and reading the corresponding insulation and conductor resistance values. After testing, the system compares the obtained insulation resistance value with a preset insulation resistance threshold and the conductor resistance value with a preset conductor resistance threshold in the database. Furthermore, the system performs anomaly detection on the detected conductor resistance value. Extreme anomalies such as infinite (open circuit) or infinitesimal (short circuit) conductor resistance values ​​are also considered as failure criteria. If the test results meet any of the following conditions: the insulation resistance value is lower than the preset insulation resistance threshold in the database, or the conductor resistance value is higher than the preset conductor resistance threshold in the database, or the conductor resistance value is infinite or infinitesimal, the cable is immediately determined to have failed, and the execution of subsequent life test cycles is terminated. Finally, the cumulative number of cable life cycles before cable failure is determined will be output as the mechanical life value of the cable under combined bending and torsional loads. This mechanical life value can accurately reflect the reliable service life of the cable after being subjected to cyclic mechanical stress under typical combined working conditions.

[0056] This embodiment also provides a function for real-time noise monitoring of the cable under test, such as... Figure 3 The circuit connection diagram for real-time cable noise detection shown is illustrated. One end of the cable under test is connected to the input terminal of the noise measurement circuit, and the other end is connected to the output terminal. No additional load is set in the circuit, thus ensuring that the electrical noise detection results mainly reflect the electrical performance of the cable itself. In this embodiment, a high-sensitivity nanovoltmeter is used to collect the voltage at both ends of the cable in real time to monitor the change in the electrical noise level of the cable during the bending and torsion combined mechanical life test. It should be noted that the diagram omits the specific clamping structure of the cable on the mechanical fixture, mainly highlighting the electrical connection relationship between the two ends of the cable and the electrical measuring device, which facilitates periodic or continuous noise detection operations. Figure 4The figure shows the curve of electrical noise voltage changing over time during the mechanical performance testing of cables. The horizontal axis represents time (in seconds), and the vertical axis represents the measured voltage (in nV). The curve reflects the fluctuation of the noise voltage of the cable under test over time during the mechanical performance testing period. Since the entire testing circuit only includes the cable under test and the voltage detection device, the voltage fluctuations in the curve can directly characterize the real-time changes in the electrical noise level of the cable under mechanical loads such as bending and torsion. By analyzing the magnitude, stability, and abrupt changes of voltage noise at different life cycle stages, the correlation between cable mechanical damage and electrical noise changes can be further revealed, providing reliable electrical indicators to support the criteria for cable mechanical life failure.

[0057] To support the aforementioned hardware signal acquisition and detection process, the accompanying host computer control software allows users to manage the test process, command issuance, and environmental status through a graphical interface. During testing, the software interface will highlight the current test step, and users can start / stop the program with a single click. After confirming the parameters, the software will automatically execute preset test commands, such as... Figure 5 The diagram shows the main interface structure of the host computer control program of the testing system involved in this embodiment. The main control interface of the host computer program is divided into three parts: a function area, a command area, and a test environment monitoring area. The function area integrates the program's run, pause, and terminate buttons, and provides entry points for parameter settings and status monitoring. The command area displays the currently loaded test program script and the applied test commands in real time, intuitively showing the key steps that the system is about to execute or is currently executing. The test environment monitoring area below is responsible for displaying the real-time temperature, humidity, air pressure, power supply voltage, and other key environmental parameters of the current experimental environment, realizing real-time monitoring and recording of external influencing factors. Figure 6 The image shows the interactive confirmation interface after the test control program starts. When the user clicks the Start button in the upper left corner of the main interface, the button will change to Stop, and a confirmation dialog box will pop up to prevent accidental operation. After the user clicks OK, the program automatically starts the test process according to the previously set parameters, sequentially executing preset tasks such as mechanical loading, noise detection, and electrical parameter measurement, achieving fully automated operation of the test process. During the specific operation of the test program, as follows... Figure 7 The image shows the interface highlighting steps during the test process. The left side of the command area highlights the currently executing step node, allowing the operator to track progress in real time. For example, when applying a bending load, the corresponding node will be dynamically highlighted. Once this step is completed, the system will automatically move on to the next test task. This automatic switching and step highlighting throughout the test process ensures the operator has intuitive control over the test status, greatly reducing the risk of manual intervention and misoperation. It also provides real-time data acquisition and curve display functions, such as... Figure 8The figure shown is a diagram of the host computer data acquisition and display interface in an embodiment of the present invention. This diagram reflects the effect of real-time electrical parameter acquisition and data visualization of the cable under test through the host computer program during the life test. The horizontal axis represents Times, indicating the sampling time (or timestamp), and the vertical axis represents Amplitude, indicating the voltage signal amplitude acquired by channel Vol(V)2182, in volts (V), with an order of magnitude of approximately 3 × 10⁻⁶. -7 V. The data acquisition system can continuously collect and record the real-time voltage of the cable at a preset sampling period, and display the voltage change trajectory in real time as a curve in the program interface throughout the entire test phase. By observing the overall trend of the curve, local fluctuation ranges, and possible abrupt change points, it is possible to assist in analyzing the electrical stability of the cable at different life cycle stages, and further reveal the correlation between mechanical damage and changes in electrical performance. The figure also demonstrates the visualization capabilities of the host computer acquisition system in this embodiment, including channel selection, time format switching, and automatic X / Y axis adjustment, providing testers with an intuitive and efficient basis for data monitoring and subsequent analysis.

[0058] This embodiment also provides a cable bending and torsion composite mechanical life testing device, such as... Figure 9 , Figure 10 The diagram shows the structure of the cable bending and torsion composite mechanical life testing equipment. Figure 1 Schematic diagram of the composite mechanical life testing equipment for cable bending and torsion Figure 2 It includes: a lower turntable 1, which is fixedly installed on the equipment base and is used to clamp and drive one end of the cable to apply torsional load; a guide rail 2, which is used to support and guide the upper turntable to move precisely in the vertical direction (Z-axis) to facilitate the adjustment of the distance between the upper turntable 3 and the lower turntable 1 to set the bending radius of the cable; and an upper turntable 3, which is set above the guide rail 2 and can be lifted and rotated by a matching drive mechanism, used to clamp the other end of the cable and cooperate to complete the application of torsional load and bending load. Figure 9 and Figure 10 Together, they reflect the key structure of the equipment and its spatial arrangement, providing a basis for the precise composite loading of cable bending and torsional loads.

[0059] Specifically, the lower turntable 1 is fixed on the equipment base and is driven to rotate by the lower turntable drive motor (built into the lower turntable 1) to clamp and drive one end of the cable to rotate, thereby applying torsional load to the cable.

[0060] The upper turntable 3 is mounted on the guide rail 2, which can move up and down along the Z-axis, and is driven to rotate by the upper turntable drive motor (built into the upper turntable 3). It is used to clamp the other end of the cable and to apply torsional load to the other end of the cable. The upper turntable 3 can be adjusted in the vertical direction by the Z-axis drive mechanism (not shown in the figure), thereby adjusting the distance between the upper and lower turntables to control the bending amplitude of the cable.

[0061] Guide rail 2 is used to support and guide the upper turntable 3 to move precisely up and down along the Z-axis (vertical direction).

[0062] The Z-axis drive mechanism (not shown in the figure) is connected to the upper turntable 3 to achieve precise vertical lifting and lowering of the upper turntable 3, and is used to set and adjust the bending radius or curvature of the cable.

[0063] The clamping system is used to firmly clamp both ends of the cable under test onto the upper and lower turntables respectively using clamps. The clamps can be adapted to different cable diameters and support quick clamping.

[0064] Preferably, the clamping system's main body is made of a non-magnetic material to avoid the influence of metallic magnetism on the electrical performance or dynamic response of the cable end, especially suitable for testing cables containing non-ferrous metal connectors such as brass, preventing test errors caused by the metal damping effect. Furthermore, the clamp's contact area with the cable is provided with a soft buffer layer or covering structure, preferably made of a highly elastic polymer material, to reduce localized stress concentration on the cable during clamping and periodic movement, avoiding mechanical damage such as scratches and indentations to the cable sheath and connectors during clamping and shaking. In addition, a rotary joint structure can be configured at the connection point between the clamp and the cable end as needed to prevent the cable end from tangling, pulling, or structural damage under torsional loads, further improving the adaptability of the testing fixture and the protection of the cable sample.

[0065] The rotary drive system includes drive motors (each built into the corresponding turntable) that cooperate with the upper and lower turntables to achieve synchronous or differential rotation of the upper and lower turntables so as to apply compound bending and torsional loads in a single cycle.

[0066] The monitoring system, built into a cable bending and torsion composite mechanical life testing device, specifically includes an electrical monitoring module, a force / torque sensor and a cycle counter. It can detect and record the electrical performance parameters, stress conditions and cycle number of the cable in real time during the test, and automatically stop the machine when the parameters are abnormal or the cable fails.

[0067] The control system is built into a cable bending and torsion composite mechanical life testing device. It is used to set test parameters, automatically control the composite loading process, collect and analyze test data, and realize automatic termination and data output linked with life criteria.

[0068] The safety protection system (not shown in the figure) includes an outer protective cover, limit switches, and an emergency stop button, which are used to ensure the safety of operators and the testing process.

[0069] Embodiment 2 of the present invention: Based on Embodiment 1, an automatic pause alarm mechanism is introduced to enhance the safety of the testing process and the response capability to abnormal events. Specifically, during the execution of the life test cycle, the loading status of bending and torsional loads, error signals, and compensation parameters are monitored in real time, and the validity of the current cycle is dynamically determined. When it is detected that the proportion of abnormal sampling moments after the end of a single life test cycle exceeds the preset threshold proportion in the database, or when any of the following situations occurs during the entire testing process: N consecutive life cycles (N is a preset value in the database) are determined to be incompletely valid, the current test is automatically paused, and an alert is issued to the operator through audible and visual alarms, interface pop-ups, etc.

[0070] The specific detection steps for the abnormal sampling time ratio exceeding the preset threshold ratio after the completion of the above single life test cycle are as follows: After the completion of the single life test cycle, count the number of abnormal sampling times and the total number of sampling times, divide the number of abnormal sampling times by the total number of sampling times to obtain the abnormal sampling time ratio, and if the abnormal sampling time ratio exceeds the preset threshold ratio, the test will be automatically paused and an alarm will be triggered.

[0071] Embodiment 3 of the present invention: Based on Embodiment 1 or 2, if the cable to be tested is a high-frequency cable, then when performing electrical performance testing on this type of cable, it is necessary to further adapt to the signal integrity and transmission performance criteria specific to high-frequency cables. This embodiment specifically includes the following steps: First, after each lifetime test cycle, a vector network analyzer or equivalent high-frequency testing equipment is used to automatically detect the key radio frequency parameters of the high-frequency cable under test. The key radio frequency parameters mainly include reflection loss and transmission loss, where reflection loss is used to evaluate the signal reflection at the input end, and transmission loss is used to characterize the signal transmission efficiency between the two ports. During the test, the automatic control module connects both ends of the cable to the high-frequency test ports respectively, and obtains the key radio frequency parameters in the typical operating frequency band according to the preset frequency scanning range and bandwidth. The detected reflection loss and transmission loss are compared with the preset criteria in the database. Specifically, if the test results show that the reflection loss is higher than the preset reflection loss threshold, or the transmission loss is lower than the preset transmission loss threshold, then the cable is considered to have failed and cannot meet the high-frequency signal integrity requirements. At this time, the subsequent lifetime test cycles are automatically stopped, and the current lifetime cycle number is taken as the final mechanical lifetime value of the cable. The above testing process enables the determination of the actual failure behavior of high-frequency cables under combined bending and torsional loads, preventing latent failures caused by signal distortion, increased loss, and other issues, thereby improving the scientific rigor and applicability of life assessment.

[0072] Embodiment 4 of this invention: Based on Embodiments 1, 2, or 3, if the cable under test is a coaxial cable, then when performing electrical performance testing on this type of cable, in addition to the conventional insulation resistance, conductor resistance, and key radio frequency parameter tests, it is also necessary to specifically test the insulation isolation performance between the signal core and the outer shielding layer of the coaxial cable. Specifically, after each life test cycle, using a switch or a special fixture, the signal core and outer shielding layer of the coaxial cable under test are connected to the two test ports of an insulation resistance tester. Under a specified voltage condition, the insulation resistance value between the core and the shielding layer is measured. If the insulation resistance value is found to be lower than the minimum insulation threshold preset in the database for coaxial cables, or if the tester detects a leakage current exceeding the preset upper limit of the leakage current in the database, or if the insulation resistance suddenly drops to a minimum value during the test, then the coaxial cable is determined to have lost its effective electromagnetic shielding and isolation function and has failed. This testing process can comprehensively reflect the insulation isolation and high-frequency performance degradation of coaxial cables under multi-cycle composite stress, providing scientific and reliable data for cable selection and life management in practical applications.

[0073] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0074] The above description is only an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for testing the combined mechanical life of cables under bending and torsion, characterized in that, The method includes: S1. Under preset test conditions, periodic bending loads and torsional loads are applied to the cable under test based on the test equipment, and the target loading path corresponding to the bending load and torsional load in each life test cycle is set. The target loading path includes at least the loading sequence, loading amplitude and loading process. S2. During each life test cycle, test data reflecting the bending load state and torsional load state are collected in real time, and the execution state of the bending load and torsional load relative to the target loading path is determined based on the test data. S3. Based on the execution status, determine whether the bending load and torsional load meet the consistency requirements. If the bending load and torsional load meet the consistency requirements, continue to execute the life test. S4. When it is determined that the bending load and the torsional load do not meet the consistency requirements, the current bending load application process and / or torsional load application process are adjusted so that the bending load and the torsional load converge to the target loading path in the subsequent loading process. S5. After the current life test cycle ends, evaluate the validity and completeness of the current life test cycle in the life statistics, and thereby determine the number of life cycles of the current life test cycle to be included in the cable's life cycle count. S6. Repeat steps S1 to S5 until the cable reaches the preset failure criterion, thereby obtaining the mechanical life of the cable under bending and torsional combined load.

2. The method for testing the combined mechanical life of cables under bending and torsion as described in claim 1, characterized in that, The specific analysis steps for determining the execution status of bending load and torsional load relative to the target loading path based on the test data are as follows: During the life test cycle, actual state data of bending load and torsional load are collected at a preset sampling period, and a timestamp is added to each sample data. The actual bending load and torsional load state data for each sampling period are compared time-by-time with the target bending load time series and target torsional load time series of the current cycle to obtain the following error signals: By comparing the differences between the actual loading progress and the target loading progress of the bending load and torsional load at each sampling time, the bending progress error value and the torsional progress error value at each sampling time are obtained. By comparing the differences between the actual bending load and torsional load amplitudes at each sampling time and their respective target amplitudes, the bending amplitude error value and the torsional amplitude error value at each sampling time are obtained. The synchronicity of the loading process of bending load and torsional load at each sampling time is analyzed. By comparing the target synchronization relationship between the two on the time axis with the actual synchronization situation, the phase error value at each sampling time is obtained. The bending progress error value, torsional progress error value, bending amplitude error value, torsional amplitude error value, and phase error value at each sampling time are combined to form the execution status of the bending load and torsional load relative to the target loading path.

3. The method for testing the combined mechanical life of cables under bending and torsion as described in claim 1, characterized in that, Based on the execution state, it is determined whether the bending load and torsional load meet the consistency requirements. The specific determination process is as follows: If the bending progress error exceeds the preset allowable range of bending progress error at a certain sampling time, the current sampling time will be recorded as the bending progress abnormal time. If the torsional progress error exceeds the preset torsional progress error allowable range at a certain sampling time, the current sampling time will be recorded as the torsional progress abnormal time. If the bending amplitude error exceeds the preset allowable range of bending amplitude error at a certain sampling time, the current sampling time will be recorded as the bending amplitude abnormal time. If the torsional amplitude error exceeds the preset torsional amplitude error allowable range at a certain sampling time, the current sampling time will be recorded as the torsional amplitude abnormal time. If the phase error exceeds the preset allowable phase error range at a certain sampling time, the current sampling time is recorded as the phase abnormality time. If a sampling moment is determined to be one or more of the following: abnormal bending progress, abnormal torsional progress, abnormal bending amplitude, abnormal torsional amplitude, and abnormal phase, then the bending load and torsional load at that sampling moment are immediately determined to be inconsistent. Otherwise, the bending load and torsional load at that sampling moment are determined to be consistent, and the life test continues.

4. The method for testing the combined mechanical life of cables under bending and torsion as described in claim 1, characterized in that, When it is determined that the bending load and torsional load do not meet the consistency requirement, the current bending load application process and / or torsional load application process are adjusted, and the specific steps are as follows: The bending progress error deviation value is obtained based on the analysis of bending progress error and the allowable range of bending progress error; The deviation value of the torsional schedule error is obtained based on the analysis of the torsional schedule error and the allowable range of the torsional schedule error. The bending amplitude error deviation value is obtained based on the bending amplitude error and the allowable range of bending amplitude error; The torsional amplitude error deviation value is obtained based on the analysis of the torsional amplitude error and the allowable range of torsional amplitude error; The phase error deviation value is obtained based on the phase error and the allowable phase error interval analysis. Using the bending progress error deviation value, torsion progress error deviation value, bending amplitude error deviation value, and torsion amplitude error deviation value as query keys, respectively, the bending drive rate adjustment value, torsion drive rate adjustment value, bending load amplitude adjustment value, and torsion load amplitude adjustment value can be obtained. If the phase error deviation value is less than zero, the bending drive speed increase is extracted from the phase-bending mapping table based on the phase error deviation value; if the phase error deviation value is greater than zero, the torsional drive speed increase is extracted from the phase-torsion mapping table based on the phase error deviation value. The bending drive rate adjustment value, torsional drive rate adjustment value, bending load amplitude adjustment value, torsional load amplitude adjustment value, bending drive speed increase and torsional drive speed increase are combined as a set of compensation parameters to adjust the current bending load application process and / or torsional load application process, and the life test is continued after adjustment.

5. The method for testing the combined mechanical life of cables under bending and torsion as described in claim 1, characterized in that, The evaluation of the validity and completeness of the current lifetime test cycle in lifetime statistics after the current lifetime test cycle has been completed includes the following steps: If there are no sampling moments in the current life test cycle where the bending load and torsional load do not meet the consistency requirements, then the effective completeness evaluation result of the current life cycle is recorded as the cycle is completely effective. If there are sampling moments where the bending load and torsional load do not meet the consistency requirements, the effective completeness assessment result of the current life cycle is recorded as an incomplete cycle.

6. The method for testing the combined mechanical life of cables under bending and torsion as described in claim 1, characterized in that, The specific steps for determining the number of life cycles to be included in the current life test cycle for the cable are as follows: If the current life cycle is a fully valid cycle, then the current life test cycle will be counted as 1 in the cable's life cycle count. If the current life cycle is not fully valid, the compensation parameter set corresponding to each abnormal sampling time is obtained, the current life test cycle is recalculated and counted, and the recalculated result is used as the current life test cycle to count the cable's life cycle number.

7. The method for testing the combined mechanical life of cables under bending and torsion as described in claim 6, characterized in that, The specific steps for calculating and counting the current lifetime test cycle are as follows: The compensation parameter sets corresponding to each abnormal sampling time are summed to obtain the total value of bending drive rate adjustment, the total value of torsional drive rate adjustment, the total value of bending load amplitude adjustment, the total value of torsional load amplitude adjustment, the total value of bending drive speed increase, and the total value of torsional drive speed increase. Using the total value of bending drive rate adjustment, the total value of torsion drive rate adjustment, the total value of bending load amplitude adjustment, the total value of torsion load amplitude adjustment, the total value of bending drive speed increase, and the total value of torsion drive speed increase as query keys, the following can be obtained: bending drive first proportional coefficient, torsion drive first proportional coefficient, bending load amplitude proportional coefficient, torsion load amplitude proportional coefficient, bending drive second proportional coefficient, and torsion drive speed second proportional coefficient. The current life test cycle is calculated and counted based on the first proportional coefficient of bending drive, the first proportional coefficient of torsion drive, the proportional coefficient of bending load amplitude, the proportional coefficient of torsion load amplitude, the second proportional coefficient of bending drive, and the second proportional coefficient of torsion drive speed. This count is then used as the current life test cycle to count the cable's life cycle count.

8. The method for testing the combined mechanical life of cables by bending and torsion as described in claim 1, characterized in that, The process continues until the cable reaches a preset failure criterion, thereby obtaining the mechanical life of the cable under combined bending and torsional loads, specifically as follows: After each life test cycle, the electrical performance of the cable is automatically tested. If the cable meets one or more of the preset failure criteria, the cable is determined to be in failure, the life test is terminated, and the current life cycle number of the cable is obtained as the mechanical life value of the cable under bending and torsional combined load.

9. The method for testing the combined mechanical life of cables under bending and torsion as described in claim 1, characterized in that, Under preset test conditions, the test equipment applies periodic bending and torsional loads to the cable under test, and sets the target loading path for the bending and torsional loads in each life test cycle. The specific steps are as follows: Set test condition parameters that include at least environmental conditions and loading frequency; Set the target loading amplitude, rate and loading sequence for bending load and torsional load respectively, and generate the target loading path parameter set; Initialize the test equipment and complete the installation and calibration of the cables; By importing the target loading path parameters into the equipment's automatic control system, periodic combined bending and torsional loads can be applied. Perform system checks to ensure the equipment is operating on the target path and is ready to enter the life test cycle.

10. A testing device employing the cable bending and torsion composite mechanical life testing method as described in any one of claims 1-9, comprising: The lower turntable is fixed on the equipment base and is driven to rotate by the lower turntable drive motor. It is used to clamp and drive one end of the cable to rotate, so as to apply torsional load to the cable. The upper turntable is set on a guide rail that can move up and down along the Z-axis and is driven to rotate by the upper turntable drive motor. It is used to clamp the other end of the cable and to apply torsional load to the other end of the cable. The upper turntable can be adjusted in the vertical direction through the Z-axis drive mechanism, thereby adjusting the distance between the upper and lower turntables to control the bending amplitude of the cable. The guide rail is used to support and guide the upper turntable to move precisely up and down along the Z-axis (vertical direction); The Z-axis drive mechanism, connected to the upper turntable, enables precise vertical lifting and lowering of the upper turntable, and is used to set and adjust the bending radius or curvature of the cable. A clamping system is used to firmly clamp both ends of the cable to be tested onto the upper and lower turntables respectively using clamps. The clamps can be adapted to different cable diameters and support quick clamping. A rotary drive system, including a drive motor that works with the upper and lower turntables, is used to achieve synchronous or differential rotation of the upper and lower turntables so as to apply compound bending and torsional loads in a single cycle. The monitoring system is built into a cable bending and torsion composite mechanical life testing device. Specifically, it includes a power-on monitoring module, a force / torque sensor and a cycle counter. It can detect and record the electrical performance parameters, stress conditions and cycle number of the cable in real time during the test, and automatically stop when the parameters are abnormal or the cable fails. The control system is built into a cable bending and torsion composite mechanical life testing device. It is used to set test parameters, automatically control the composite loading process, collect and analyze test data, and realize automatic termination and data output linked with life criteria. The safety protection system, including protective enclosure, limit switches, and emergency stop buttons, is used to ensure the safety of operators and the testing process.

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