CN-122016512-A - Cable bending and torsion composite mechanical life test method and test equipment

CN122016512ACN 122016512 ACN122016512 ACN 122016512ACN-122016512-A

Abstract

The invention provides a cable bending torsion composite mechanical life test method and test equipment, which relate to the technical field of cable aging test and comprise the following steps: applying periodic bending load and torsion load to the cable, setting a target loading path, collecting test data in real time, determining an execution state, judging whether the bending load and the torsion load meet consistency requirements, adjusting the current bending load applying process and/or the torsion load applying process when judging that the bending load and the torsion load do not meet the consistency requirements, determining the life cycle number of the cable counted by the current life test cycle, and obtaining the mechanical life of the cable under the action of the bending and torsion composite load. The invention solves the technical problems of asynchronous bending and torsion load application, load path deviation, damage accumulated distortion and inaccurate service life evaluation result in the actual composite load test, and ensures the consistency of the composite fatigue load path and the reliability of test conclusion.

Inventors

SHEN SHIPENG
LIU LIMIN
GUO CHENYANG
Zheng Xichao
HE JINCHENG

Assignees

多场低温科技（北京）有限公司

Dates

Publication Date: 20260512
Application Date: 20260318

Claims (10)

1. A method for testing the life of a cable bending torsion composite machine, the method comprising: s1, under a preset test working condition, applying periodic bending load and torsion load to a cable based on test equipment, and setting a target loading path corresponding to the bending load and the torsion load in each life test cycle, wherein the target loading path at least comprises a loading time sequence, a loading amplitude and a loading process; s2, in the execution process of each life test cycle, test data reflecting the bending load state and the torsion load state are collected in real time, and the execution state of the bending load and the torsion load relative to the target loading path is determined based on the test data; S3, judging whether the bending load and the torsion load meet the consistency requirement according to the execution state, and continuously executing the service life test when judging that the bending load and the torsion load meet the consistency requirement; S4, when the bending load and the torsion load are judged to not meet the consistency requirement, adjusting the current bending load application process and/or the torsion load application process so as to enable the bending load and the torsion load to converge towards the target loading path in the subsequent loading process; s5, after the current life test cycle is finished, evaluating the validity and completeness of the current life test cycle in life statistics, so as to determine the life cycle number of the cable counted by the current life test cycle; S6, repeating the steps S1 to S5 until the cable reaches a preset failure criterion, so that the mechanical life of the cable under the action of the bending and torsion compound load is obtained.
2. The method for testing the bending and torsional composite mechanical life of a cable according to claim 1, wherein the determining the execution state of the bending load and the torsional load relative to the target loading path based on the test data comprises the following steps: In the executing process of life test cycle, respectively acquiring actual state data of bending load and torsion load in a preset sampling period, and adding a time stamp to each sampling data; the actual bending load and torsion load state data under each sampling period are respectively compared with the target bending load time sequence and the target torsion load time sequence of the current cycle time by time to obtain the following error signals: comparing the difference between the actual loading progress and the target loading progress of the bending load and the torsion load at each sampling time to obtain a bending progress error value at each sampling time and a torsion progress error value at each sampling time; Comparing the difference between the amplitude values of the actual bending load and the torsion load at each sampling moment and the respective target amplitude values to obtain a bending amplitude error value at each sampling moment and a torsion amplitude error value at each sampling moment; Analyzing the synchronicity of the loading process of the bending load and the torsion load at each sampling moment, and obtaining a phase error value at each sampling moment by comparing the target synchronicity relationship and the actual synchronicity condition of the bending load and the torsion load on a time axis; and combining the bending progress error value at each sampling time, the torsion progress error value at each sampling time, the bending amplitude error value at each sampling time, the torsion amplitude error value at each sampling time and the phase error value at each sampling time as the execution state of the bending load and the torsion load relative to the target loading path.
3. The method for testing the life of a cable bending and torsion composite machine according to claim 1, wherein the judging whether the bending load and the torsion load meet the consistency requirement according to the execution state comprises the following specific judging process: If the bending progress error at a certain sampling time exceeds a preset bending progress error allowable interval, the current sampling time is recorded as a bending progress abnormal time; if the torsion progress error at a certain sampling time exceeds a preset torsion progress error allowable interval, the current sampling time is recorded as a torsion progress abnormal time; if the bending amplitude error at a certain sampling time exceeds a preset bending amplitude error allowable interval, the current sampling time is recorded as the abnormal bending amplitude time; if the torsion amplitude error at a certain sampling time exceeds a preset torsion amplitude error allowable interval, the current sampling time is recorded as the abnormal torsion amplitude time; If the phase error at a certain sampling time exceeds a preset phase error allowable interval, the current sampling time is recorded as a phase abnormal time; If a certain sampling time is judged to be one or more of bending progress abnormal time, torsion progress abnormal time, bending amplitude abnormal time, torsion amplitude abnormal time and phase abnormal time, immediately judging that the bending load and the torsion load at the sampling time do not meet the consistency requirement, otherwise, judging that the bending load and the torsion load at the sampling time meet the consistency requirement, and continuously executing the life test.
4. The method for testing the bending and torsion composite mechanical life of a cable according to claim 1, wherein when the bending load and the torsion load are judged not to meet the consistency requirement, the current bending load application process and/or the torsion load application process are adjusted, and the specific steps are as follows: obtaining a bending progress error deviation value based on the bending progress error and the bending progress error allowable section analysis; analyzing and obtaining a torsion progress error deviation value based on the torsion progress error and a torsion progress error allowable interval; Obtaining a bending amplitude error deviation value based on the bending amplitude error and the bending amplitude error allowable interval analysis; Analyzing and obtaining a torsion amplitude error deviation value based on the torsion amplitude error and a torsion amplitude error allowable interval; Obtaining a phase error deviation value based on the phase error and the phase error allowable interval analysis; Respectively taking the bending progress error deviation value, the torsion progress error deviation value, the bending amplitude error deviation value and the torsion amplitude error deviation value as query key values, and querying to obtain a bending driving speed adjusting value, a torsion driving speed adjusting value, a bending loading amplitude adjusting value and a torsion loading amplitude adjusting value; If the phase error deviation value is smaller than zero, extracting a bending driving speed lifting amount based on the phase error deviation value from a phase-bending mapping table, and if the phase error deviation value is larger than zero, extracting a torsion driving speed lifting amount based on the phase error deviation value from a phase-torsion mapping table; And adjusting the current bending load applying process and/or the torsion load applying process according to the obtained bending driving speed adjusting value, torsion driving speed adjusting value, bending loading amplitude adjusting value, torsion loading amplitude adjusting value, bending driving speed lifting amount and torsion driving speed lifting amount which are combined as compensation parameter sets, and continuously executing the service life test after adjustment.
5. A method of testing the life of a cable bend torsion composite machine according to claim 1, wherein said evaluating the validity of the current life test cycle in life statistics after the end of the current life test cycle comprises the steps of: in the current life test cycle, if no sampling time exists at which the bending load and the torsion load do not meet the consistency requirement, the effective completeness assessment result of the current life cycle is recorded as the cycle complete validity; and if the sampling time at which the bending load and the torsion load do not meet the consistency requirement exists, marking the effective completeness assessment result of the current life cycle as the incomplete validity of the cycle.
6. A method of testing the life of a cable bending and torsion composite machine according to claim 1, wherein the determining the number of life cycles of the cable is performed by the following steps: If the current life cycle is completely effective, counting the life cycle number of the current life test cycle into the cable as 1; and if the current life cycle is not completely effective, acquiring a compensation parameter set corresponding to each abnormal sampling moment, carrying out conversion counting on the current life test cycle, and taking the converted result as the life cycle number of the current life test cycle to be counted into the cable.
7. A method of testing the bending and torsional composite mechanical life of a cable as in claim 6, wherein the performing a reduced count of current life test cycles comprises the steps of: respectively adding compensation parameter sets corresponding to different sampling moments to obtain a bending driving speed adjusting total value, a torsion driving speed adjusting total value, a bending loading amplitude adjusting total value, a torsion loading amplitude adjusting total value, a bending driving speed lifting total amount and a torsion driving speed lifting total amount; respectively taking the bending driving speed adjusting total value, the torsion driving speed adjusting total value, the bending loading amplitude adjusting total value, the torsion loading amplitude adjusting total value, the bending driving speed lifting total amount and the torsion driving speed lifting total amount as query key values, and obtaining a bending driving first proportion coefficient, a torsion driving first proportion coefficient, a bending loading amplitude proportion coefficient, a torsion loading amplitude proportion coefficient, a bending driving second proportion coefficient and a torsion driving speed second proportion coefficient by query; and analyzing the first bending drive proportion coefficient, the first torsion drive proportion coefficient, the bending loading amplitude proportion coefficient, the torsion loading amplitude proportion coefficient, the second bending drive proportion coefficient and the second torsion drive speed proportion coefficient to obtain a current life test cycle conversion count value, and taking the current life test cycle conversion count value as the life cycle number of the cable.
8. The method for testing the bending and torsion composite mechanical life of a cable according to claim 1, wherein the mechanical life of the cable under the bending and torsion composite load is obtained until the cable reaches a preset failure criterion, specifically: After each life test cycle, the cable is automatically subjected to electrical performance detection, if the cable meets one or more of preset failure criteria, the cable is judged to fail, the life test is terminated, and the current life cycle number of the cable is obtained and is used as the mechanical life value of the cable under the action of bending and torsion compound load.
9. The method for testing the bending and torsion composite mechanical life of a cable according to claim 1, wherein under a preset test condition, a periodic bending load and a periodic torsion load are applied to the cable to be tested based on a test device, and a target loading path corresponding to the bending load and the torsion load in each life test cycle is set, and the specific steps are as follows: setting test working condition parameters at least comprising environmental conditions and loading frequency; respectively setting target loading amplitude, speed and loading time sequence of bending load and torsion load, and generating a target loading path parameter set; Initializing test equipment and completing the installation and calibration of cables; the target loading path parameters are led into an automatic control system of the equipment, so that periodic bending and torsion load compound loading is realized; and (3) performing system detection to ensure that the equipment runs along a target path and is ready to enter a life test cycle.
10. Test apparatus applying a cable bending torsion composite mechanical life test method according to any of claims 1-9, comprising: The lower turntable is fixed on the equipment base, is driven to rotate by a lower turntable driving motor and is used for clamping and driving one end of the cable to rotate so as to realize the application of torsional load of the cable; The upper turntable is arranged on a guide rail capable of moving up and down along the Z-axis direction, is driven to rotate by an upper turntable driving motor and is used for clamping the other end of the cable and cooperatively realizing the application of torsional load at the other end of the cable, and the upper turntable can realize the position adjustment in the vertical direction through a Z-axis driving mechanism so as to adjust the distance between the upper turntable and the lower turntable to control the bending amplitude of the cable; a guide rail for supporting and guiding the upper turntable to precisely move up and down along a Z axis (vertical direction); The Z-axis driving mechanism is connected with the upper turntable, realizes accurate vertical lifting of the upper turntable and is used for setting and adjusting the bending radius or curvature of the cable; the clamping system is used for respectively and firmly clamping the two ends of the cable to be tested on the upper turntable and the lower turntable through clamps, and the clamps can be adapted to different cable diameters and support rapid clamping; The rotary driving system comprises a driving motor matched with the upper rotary table and the lower rotary table, and is used for realizing synchronous or differential rotation of the upper rotary table and the lower rotary table so as to apply compound bending and torsion loads in a single cycle; The monitoring system is arranged in cable bending and torsion composite mechanical life test equipment and specifically comprises an energization monitoring module, a force/torque sensor and a cycle counter, and can detect and record electrical performance parameters, stress conditions and cycle numbers of the cable in the test process in real time and automatically stop when the parameters are abnormal or the cable fails; The control system is arranged in the cable bending and torsion composite mechanical life test equipment and is used for setting test parameters, automatically controlling the composite loading process, collecting and analyzing test data and realizing automatic termination and data output linked with life criteria; the safety protection system comprises an outer cover protection, a limit switch and an emergency stop button and is used for guaranteeing the safety of operators and a testing process.

Description

Cable bending and torsion composite mechanical life test method and test equipment Technical Field The invention relates to the technical field of cable aging tests, in particular to a cable bending and torsion composite mechanical life test method and test equipment. Background The cable is used as a transmission carrier of electric energy and signals, and the fatigue life of the cable under the actual working condition is particularly important to be accurately estimated. Cables are often subjected to both bending and torsional stresses in practical applications, particularly in the context of robotic joints, drag chain systems, and the like. In order to truly simulate the environment of use of a cable, many test equipment needs to be able to apply bending and torsional loads simultaneously to evaluate the fatigue life of the cable under composite stress. However, during actual cable bending-torsion composite load testing, it is often difficult to achieve complete synchronization of bending and torsion loads under ideal conditions. The generation of such synchronization errors results from a variety of unavoidable integration factors of the test equipment at both the mechanical structure and the control system. Firstly, unavoidable friction, gaps and elastic deformation of materials exist in parts such as gears, couplings and the like in a mechanical structure in the load transmission process, for example, tiny time sequence dislocation is generated between target displacement and actual displacement due to gear meshing gaps, secondly, the response speed and inertia characteristics of different driving mechanisms (such as a bending motor and a torsion motor) are different, so that the application time and the application speed of a load are difficult to keep completely consistent in a high-frequency and multi-cycle fatigue test, thirdly, the problems of signal transmission delay, limited adjustment bandwidth and the like exist in a control system, and the difficulty of load synchronization is further increased. For example, the test equipment sets that bending and torsion should peak at the same time in the fifth second in each cycle, but the bending end reaches 2cm in advance in a certain cycle due to gear backlash or motor response delay, while the torsion end reaches only half of the expected angle due to inertia lag. This timing discrepancy causes the composite stress path experienced by the cable to deviate from the set ideal path, thereby causing fatigue damage to accumulate. The existence of the synchronization error not only weakens the repeatability and comparability of the test result, but also directly influences the accurate assessment of the fatigue life of the cable. Since the multilayer structure inside the cable is highly sensitive to load synchronicity, small synchronization errors may lead to local strain concentration, interlayer slip cadence changes, and thus induce premature failure or non-target failure modes. These errors gradually accumulate and affect the life assessment of the cable during long, high frequency fatigue tests, especially during multiple cycles. Disclosure of Invention In view of the above, the embodiment of the invention provides a cable bending torsion composite mechanical life test method and test equipment, which solve the technical problems of load path deviation, damage accumulated distortion and inaccurate life evaluation result caused by asynchronous bending and torsion load application in actual composite loading test. Through on-line detection and closed loop compensation of the synchronous error, the consistency of the composite fatigue loading path and the reliability of the test conclusion are ensured. The embodiment of the invention provides a cable bending torsion composite mechanical life test method, which comprises the following steps: S1, under a preset test working condition, applying periodic bending load and torsion load to a cable based on test equipment, and setting a target loading path corresponding to the bending load and the torsion load in each life test cycle, wherein the target loading path at least comprises a loading time sequence, a loading amplitude and a loading process. S2, in the execution process of each life test cycle, test data reflecting the bending load state and the torsion load state are collected in real time, and the execution states of the bending load and the torsion load relative to the target loading path are determined based on the test data. S3, judging whether the bending load and the torsion load meet the consistency requirement according to the execution state, and continuously executing the service life test when judging that the bending load and the torsion load meet the consistency requirement. And S4, when judging that the bending load and the torsion load do not meet the consistency requirement, adjusting the current bending load application process and/or the torsion load application process so as to ena