Grating sensing component multi-stress coupling dynamic reliability test bench and test method

Abstract

The application discloses a grating sensing component multi-stress coupling dynamic reliability test bench and test method, belongs to the technical field of machine or structural component testing, and the test bench comprises a bottom plate, a profile frame, an encoder rotary test device, a grating ruler linear test device, a power transmission system, three comprehensive test boxes, an oil pollution and electromagnetic interference loading module and a detection and control system; a double-station parallel layout is adopted, and the grating ruler and the encoder can be subjected to multi-stress coupling test simultaneously; rotation and linear motion are realized through a servo motor driving a gear box and a screw mechanism, a high-low temperature servo cylinder applies coaxial impact load, and temperature, humidity, vibration, oil pollution and electromagnetic interference are loaded in combination; the detection and control system is independent double closed loop, synchronously collects grating, vibration, temperature and position signals, and has high-precision calibration and automatic fault determination functions. The test method adopts multi-stress acceleration loading, and can realize performance degradation monitoring, fault recording and reliability evaluation.

Description

Technical Field

[0001] This invention belongs to the field of machine or structural component testing technology, specifically relating to a multi-stress coupling dynamic reliability test bench and test method for grating sensing components (grating rulers and grating encoders). Background Technology

[0002] Grating sensing components, including grating rulers and grating encoders (hereinafter referred to as encoders), are core components of motion control systems for high-precision equipment such as CNC machine tools and industrial robots. Their fundamental function is to achieve accurate, real-time, and digital measurement of position and speed. They directly convert mechanical displacement or rotation angle into high-resolution electrical signals through the principle of optical moiré fringes.

[0003] Therefore, the performance of grating components directly determines whether equipment such as CNC machine tools, industrial robots, and precision measuring instruments can maintain stable operation and accuracy over long periods. Under complex working conditions such as continuous vibration, cyclical temperature and humidity changes, and mechanical shocks, as well as during long-term continuous operation, grating sensing components may experience various forms of failure, mainly manifested as missing or interrupted output signals, abnormal signal fluctuations and jumps, and significantly increased measurement errors, which can lead to equipment malfunction or accuracy degradation. These failures not only directly affect the dimensional accuracy and surface quality of the processed workpieces but also reduce the overall operational stability and production efficiency of the equipment. Therefore, conducting reliability tests on grating sensing components and proposing improvement measures is an effective way to improve their reliability.

[0004] As a key structural and functional component in high-precision equipment, grating sensing components require dynamic reliability testing using dedicated structural component testing equipment during actual service to evaluate their failure modes and reliability levels under complex operating conditions. In terms of testing methods, commonly used single-stress, no-load, or static testing modes are insufficient to effectively simulate the combined effects of multiple stress couplings such as vibration, temperature and humidity cycling, and mechanical loads under actual operating conditions. Furthermore, existing research often focuses on single types of grating components (such as grating rulers or encoders only), failing to support reliability testing of both grating rulers and encoders simultaneously. Therefore, developing a dedicated reliability testing platform for grating sensing components capable of simulating real complex operating conditions and simultaneously supporting both grating rulers and encoders, and conducting systematic accelerated life testing and performance degradation testing based on this platform, is of crucial engineering application value for accurately exposing potential defects, clarifying failure mechanisms, and thus significantly improving the reliability level of the component itself and the entire CNC machine.

[0005] In this invention, the grating ruler and grating encoder are not improved as simple displacement or angle measuring devices, but as structural components and key functional components under test in CNC machine tools, industrial robots and precision equipment. Their reliability, performance degradation and failure behavior are tested and evaluated under multi-stress coupling conditions through a dedicated test bench. Summary of the Invention

[0006] The purpose of this invention is to solve the above-mentioned problems and to provide a dynamic reliability test bench and test method for multi-stress coupling of grating sensing components, which is used to conduct reliability tests, performance degradation tests, failure monitoring and life assessment of the tested structural components (grating rulers and grating encoders) under dynamic operating conditions.

[0007] The technical solution adopted in this invention is as follows:

[0008] The dynamic reliability test bench for multi-stress coupling of grating sensing components includes: a working platform, a three-dimensional test chamber, a grating sensing component device system, a power transmission device system, an oil contamination loading device system, an electromagnetic interference loading device system, a detection system, and a control system.

[0009] The three-dimensional test chamber is equipped with a working platform on each of its left and right sides, both of which are placed flat on the ground;

[0010] The aforementioned grating sensing component system includes: an encoder rotation test device and a grating ruler linear test device, which are placed horizontally adjacent to each other;

[0011] The power transmission device system is connected to the encoder rotation test device, and the encoder rotation test device is connected to the grating ruler linear test device.

[0012] The encoder rotation test device includes an encoder rotation profile mounting frame, an encoder support frame, an encoder, a flange connecting shaft, an expansion sleeve, and a gearbox;

[0013] The encoder rotary profile mounting bracket includes a front upper panel and a base plate arranged parallel to each other and vertically, which are connected by profiles; the base plate is horizontally fixed above the vibration table of the three-dimensional test chamber;

[0014] The encoder support frame is fixed to the front top plate by hexagon socket screws. An expansion sleeve is provided inside the encoder support frame, and the encoder is connected to the expansion sleeve by a flange connecting shaft and encoder screws.

[0015] Furthermore, the gearbox includes a deep groove ball bearing, an upper body, a lower body, a small end cover, a large end cover, a gearbox output shaft, a gearbox input shaft, a helical gear No. 1, and a helical gear No. 2;

[0016] The upper body is fixedly connected to the lower body, and the lower body is fixedly connected to the front upper panel; both ends of the gearbox output shaft are connected to the expansion sleeve, and the gearbox input shaft drives the gearbox output shaft to rotate through the meshing of helical gear No. 1 and helical gear No. 2; one end of the gearbox input shaft is connected to the power transmission device system, and the other end is connected to the linear test device of the grating ruler.

[0017] Furthermore, the linear testing device for the grating ruler includes a linear profile mounting bracket for the grating ruler, a lead screw slide assembly, a high and low temperature servo electric cylinder, an electric cylinder support base, a grating ruler fixing base, a grating ruler, a proximity switch, a proximity switch bracket, a corner pyramid prism, an L-shaped frame, and an end panel;

[0018] The linear profile mounting bracket for the grating ruler includes a rear upper panel arranged parallel to the base plate and a profile frame between the two.

[0019] The gearbox input shaft is connected to the ball screw of the screw slide assembly via a screw coupling, transmitting power to the linear test device of the grating ruler.

[0020] The lead screw slide assembly is fixed on the rear top plate and includes a ball screw, a lead screw nut, and a T-shaped platform;

[0021] The grating ruler mounting base is fixed on the rear top plate, the grating ruler is installed on the grating ruler mounting base, and the reading head of the grating ruler is fixed to the T-shaped platform through the L-frame;

[0022] The high and low temperature servo electric cylinder is fixed to the rear upper plate by the electric cylinder support seat and is fixedly connected to the T-shaped platform.

[0023] The proximity switch bracket and the proximity switch are respectively set at both ends of the travel of the T-shaped platform; the corner cube prism is installed on the T-shaped platform through an L-shaped bracket.

[0024] Furthermore, the power transmission device system includes a synchronous AC servo motor, a power bearing housing, a power coupling, a power transmission stepped shaft, a bearing housing pad No. 1, and a bearing housing pad No. 2.

[0025] The No. 1 bearing seat pad is fixed to the left working platform, and the No. 2 bearing seat pad is fixed to the front upper panel; the power bearing seat is installed on the No. 1 bearing seat pad and the No. 2 bearing seat pad respectively, and the power bearing seat is equipped with a deep groove ball bearing.

[0026] The power transmission stepped shaft passes through the shaft hole of the three-dimensional test chamber, and its two ends are respectively connected to the output shaft of the synchronous AC servo motor and the input shaft of the gearbox through power couplings.

[0027] Furthermore, the oil pollution loading device system includes an oil storage tank, an oil suction pipe, a liquid metering pump, an oil discharge pipe, a pipe fixing block, and a pneumatic full-cone atomizing nozzle;

[0028] The oil storage tank is located below the left working platform, and the liquid metering pump is located above the left working platform;

[0029] The oil suction pipe connects the oil storage tank to the oil suction port of the liquid metering pump, and the oil discharge pipe passes through the pipe hole of the three-dimensional test chamber and is fixed by the pipe fixing block.

[0030] The pneumatic full-cone atomizing nozzle is located at one end of the oil drain pipe inside the three-dimensional test chamber, corresponding to the encoder rotation test device and the grating ruler linear test device, respectively.

[0031] Furthermore, the electromagnetic interference loading device system includes a CDN coupling / decoupling network, a function generator, and signal lines;

[0032] The function generator and CDN coupling / decoupling network are located above the right-side working platform;

[0033] The CDN coupling / decoupling network is connected to the power supply of the grating sensing component. The function generator is connected to the RF port of the CDN coupling / decoupling network through a signal line. The output of the CDN coupling / decoupling network is connected to the power supply of the encoder and the grating ruler.

[0034] Furthermore, the detection system includes a control console, a laser interferometer, an RTD temperature sensor, a triaxial piezoelectric accelerometer, an NI synchronous acquisition card, a chassis, a monitoring platform, an oil pollution monitoring unit, and an electromagnetic interference detection unit;

[0035] The monitoring platform includes a grating signal monitoring module, a vibration signal monitoring module, a position signal monitoring module, and a temperature signal monitoring module;

[0036] The oil pollution monitoring unit includes a flow sensor, a pressure sensor, and a pollution status judgment module;

[0037] The electromagnetic interference detection unit includes a voltage detection module, an interference signal monitoring module, and an electromagnetic response judgment module.

[0038] Furthermore, the control system includes an STM32 microcontroller, a differential pulse transmission module, a servo motor driver, a servo motor encoder, a digital-to-analog converter module, a servo electric cylinder driver, a force sensor, and an isolation interface module;

[0039] The STM32 microcontroller is connected to the servo motor driver via a differential pulse transmission module, and the servo motor driver drives the synchronous AC servo motor.

[0040] The servo motor encoder feeds back the signal to the STM32 microcontroller;

[0041] The STM32 microcontroller is connected to the servo cylinder driver through a digital-to-analog converter module, and the servo cylinder driver drives the high and low temperature servo cylinder.

[0042] The force sensor collects the output force of the high and low temperature servo electric cylinder and feeds it back to the STM32 microcontroller.

[0043] The control system and the detection system are electrically isolated through an isolation interface module.

[0044] Furthermore, the lead screw slide assembly also includes a bearing mounting base, a front lead screw support base, a rear lead screw support base, a connecting block, a guide rail base, a guide rail, an adjusting block, and a T-shaped extrusion block;

[0045] The front lead screw support is fixed to the rear upper panel and is internally equipped with a bearing fixing seat, an angular contact ball bearing, an oil seal, an adjusting ring, and a bearing cover.

[0046] The rear lead screw support is fixed to the rear upper panel by a connecting block, and is internally equipped with a deep groove ball bearing, a snap ring and a lead screw end cap.

[0047] The guide rail is fixed to the rear upper panel via a guide rail base, the guide rail is slidably connected to the adjustment block, and the adjustment block is fixedly connected to the T-shaped platform.

[0048] Another objective of this invention is a dynamic reliability test method for multi-stress coupling of grating sensing components.

[0049] The dynamic reliability test method for multi-stress coupling of grating sensing components, using the aforementioned dynamic reliability test bench for multi-stress coupling of grating sensing components, includes the following steps:

[0050] S1 Test Preparation: After the test bench is pre-stabilized, the temperature and humidity, vibration parameters, impact parameters of the high and low temperature servo electric cylinder, oil contamination parameters of the pneumatic full cone atomizing nozzle, and electromagnetic interference parameters of the CDN coupling / decoupling network are set through the control system.

[0051] Set the synchronous AC servo motor motion mode and adjust the proximity switch to form a limit; mount the grating ruler on the grating ruler mounting base and the encoder on the encoder support frame; calibrate the laser interferometer, RTD temperature sensor, and triaxial piezoelectric accelerometer, and set the failure judgment threshold.

[0052] S2 test operation: Start-up test, environmental stress is applied by the three comprehensive test chambers, coaxial impact load is applied by the high and low temperature servo electric cylinder, synchronous AC servo motor drives the specimen to move, and oil and electromagnetic interference are applied synchronously.

[0053] S3 Data Acquisition: The NI synchronous acquisition card and monitoring platform acquire grating signals, displacement / angle, temperature and vibration data in real time, compare them with the laser interferometer calibration values, determine failures and record fault information;

[0054] S4 Result Analysis: After the test is completed, the mean time between failures is calculated based on the fault data, the performance degradation law and failure mechanism are analyzed, and the reliability assessment is completed.

[0055] This invention provides a dynamic reliability test bench and method for multi-stress coupling of grating sensing components, belonging to the field of machine or structural component testing technology. The test bench includes a base plate, a profile frame, an encoder rotation test device, a grating ruler linear test device, a power transmission system, a three-dimensional integrated test chamber, an oil contamination and electromagnetic interference loading module, and a detection and control system. It adopts a dual-station parallel layout, enabling simultaneous multi-stress coupling tests on the grating ruler and encoder. Rotation and linear motion are achieved through a servo motor driving a gearbox and a lead screw mechanism. High and low temperature servo cylinders apply coaxial impact loads, combined with composite loading of temperature, humidity, vibration, oil contamination, and electromagnetic interference, realistically simulating service conditions. The detection and control system features independent dual closed loops, synchronously acquiring grating, vibration, temperature, and position signals, and possesses high-precision calibration and automatic fault determination functions. The test method employs multi-stress accelerated loading, enabling performance degradation monitoring, fault recording, and reliability assessment.

[0056] The beneficial effects of this invention compared to the prior art are as follows:

[0057] 1. The dynamic reliability test bench for multi-stress coupling of grating sensing components described in this invention has an environmental stress-mechanical stress composite loading system for the tested structural components (grating rulers and grating encoders). Through the coordinated operation of a three-integrated environmental loading unit, a servo electric cylinder impact unit, an oil contamination loading module, and an electromagnetic interference injection module, the tested component is simultaneously subjected to temperature, humidity, vibration, oil contamination, electromagnetic interference, and directional impact loads. Moreover, the impact direction is coaxial with the linear motion direction of the tested component, which can more realistically simulate the complex service environment of the tested grating sensing components in actual equipment.

[0058] 2. The dynamic reliability test bench for multi-stress coupling of grating sensing components described in this invention adopts a method of parallel arrangement of two modules on the same platform (grating ruler linear test module and encoder rotation test module) to construct a dynamic reliability test bench system for multi-stress coupling of grating sensing components that can simultaneously test grating rulers and grating encoders.

[0059] 3. The present invention employs a multi-stress coupling dynamic reliability test bench with grating sensors to establish a dual-closed-loop independent system with separated monitoring and control. The monitoring system and control system are separated at the hardware and electrical levels. The control system is used to realize the motion control of the servo motor and the impact loading control of the servo electric cylinder, while the monitoring system is used to synchronously acquire grating signals, position signals, vibration signals, and temperature signals. Differential transmission, shielded cables, and isolation interfaces are used to improve data stability, sampling synchronization, and anti-interference capabilities under complex stress environments. This ensures the synchronization, accuracy, and traceability of test data during reliability testing, and improves the accuracy of failure determination and reliability assessment of the tested structural components. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of the overall structure of the dynamic reliability test bench for the grating sensing component of the present invention, which is a multi-stress coupling test bench.

[0061] Figure 2 This is a top view of the dynamic reliability test bench for multi-stress coupling of the grating sensing component of the present invention;

[0062] Figure 3 This is a cross-sectional view of the power transmission device system structure of the multi-stress coupling dynamic reliability test bench for the grating sensing component of the present invention (the three integrated test chambers and working platform are omitted).

[0063] Figure 4 This is a three-dimensional structural diagram of the power transmission device system of the multi-stress coupling dynamic reliability test bench for the grating sensing component of the present invention (the three-dimensional test chamber and working platform are omitted).

[0064] Figure 5 This is a cross-sectional view of the encoder rotation test device of the multi-stress coupling dynamic reliability test bench for the grating sensing component of the present invention.

[0065] Figure 6 This is a cross-sectional view of the grating ruler linearity test device of the multi-stress coupling dynamic reliability test bench for the grating sensing component of the present invention.

[0066] Figure 7 The right view of the three-dimensional structure of the grating sensing component device system of the multi-stress coupling dynamic reliability test bench of the grating sensing component of the present invention;

[0067] Figure 8 This is a left-side three-dimensional view of the grating sensing component system of the multi-stress coupling dynamic reliability test bench for the grating sensing component of the present invention.

[0068] Figure 9 This is a top view of the three-dimensional structure of the grating sensing component device system of the multi-stress coupling dynamic reliability test bench of the grating sensing component of the present invention;

[0069] Figure 10 This is a front view of the gearbox in the grating sensing component device system of the multi-stress coupling dynamic reliability test bench of the grating sensing component of the present invention;

[0070] Figure 11 This is a cross-sectional view of the internal structure of the gearbox in the grating sensing component device system of the multi-stress coupling dynamic reliability test bench of the grating sensing component of the present invention.

[0071] Figure 12 This is a block diagram of the detection system in the multi-stress coupling dynamic reliability test bench for the grating sensing component of the present invention;

[0072] Figure 13 This is a block diagram of the control system of the multi-stress coupling dynamic reliability test bench for the grating sensing component of the present invention;

[0073] Figure 14 This is a flowchart of the dynamic reliability test method for grating sensing components under multi-stress coupling, which is the multi-stress coupling dynamic reliability test bench for grating sensing components of the present invention.

[0074] In the attached diagram:

[0075] 1. Base plate; 2. No. 1 profile; 3. Corner fittings; 4. T-bolts; 5. Nuts; 6. Front top panel; 7. Socket head screws; 8. Encoder support bracket; 9. Support bracket screws;

[0076] 10. Encoder; 11. Flange connecting shaft; 12. Encoder screw; 13. Expansion sleeve; 14. Gearbox; 15. Gearbox screw; 16. Lead screw coupling; 17. Fastening nut; 18. Adjusting ring; 19. Bearing cover;

[0077] 20. Bearing mount; 21. Angular contact ball bearing; 22. Oil seal; 23. Front lead screw support; 24. Ball screw; 25. Lead screw nut; 26. T-platform; 27. High and low temperature servo cylinder; 28. Rear lead screw support; 29. ​​Deep groove ball bearing; 30. Snap ring; 31. Lead screw end cap screw; 32. Lead screw end cap; 33. Cylinder support; 34. Profile No. 4; 35. Socket head cap screw; 36. Profile No. 5; 37. Profile No. 6; 38. Profile No. 2; 39. Breather;

[0078] 40. Inspection hole cover; 41. Upper body; 42. Lower body; 43. Small end cover; 44. Large end cover; 45. Plug; 46. Oil dipstick; 47. Gearbox output shaft; 48. Gearbox input shaft; 49. Helical gear No. 1; 50. Helical gear No. 2;

[0079] 51. Rear top panel; 52. Connecting block; 53. Grating ruler mounting base; 54. Grating ruler; 55. L-shaped bracket; 56. T-shaped extrusion block; 57. Guide rail base; 58. Guide rail; 59. Adjusting block; 60. Proximity switch nut;

[0080] 61. Proximity switch; 62. Proximity switch bracket; 63. Profile No. 3; 64. Pyramidal prism; 65. L-shaped bracket; 66. End panel; 67. Synchronous AC servo motor; 68. Power bearing housing; 69. Power coupling; 70. Power transmission stepped shaft;

[0081] 71. Bearing housing pad No. 1; 72. Bearing housing pad No. 2; 73. Oil reservoir; 74. Oil suction pipe; 75. Liquid metering pump; 76. Oil discharge pipe; 77. Pipe fixing block; 78. Pneumatic full-cone atomizing nozzle; 79. Working platform;

[0082] 80. CDN coupling / decoupling network; 81. Function generator; 82. Signal line; 83. Control console; 84. Three-dimensional integrated test chamber; 85. Laser interferometer; 86. RTD temperature sensor; 87. Triaxial piezoelectric accelerometer; 88. NI synchronous acquisition card; 89. Chassis;

[0083] 90. Monitoring platform; 901. Grating signal monitoring module; 902. Vibration signal monitoring module; 903. Position signal monitoring module; 904. Temperature signal monitoring module; 91. Oil pollution monitoring unit; 911. Flow sensor; 912. Pressure sensor; 913. Pollution status judgment module; 92. Electromagnetic interference detection unit; 921. Voltage detection module; 922. Interference signal monitoring module; 923. Electromagnetic response judgment module;

[0084] 93. STM32 microcontroller; 94. Differential pulse transmission module; 95. Servo motor driver; 96. Servo motor encoder; 97. Digital-to-analog converter module; 98. Servo electric cylinder driver; 99. Force sensor; 100. Isolation interface module. Detailed Implementation

[0085] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments: The present invention aims to simulate the complex working conditions faced by grating sensing components (including grating rulers and grating encoders) in actual operation, and obtain their reliability data through multi-stress coupling loading, thereby proposing a multi-stress coupling dynamic reliability test bench and test method for grating sensing components.

[0086] Example 1:

[0087] Please see Figure 1-13The dynamic reliability test bench for multi-stress coupling of grating sensing components includes: a working platform 79, a three-dimensional test chamber 84, a grating sensing component device system, a power transmission device system, an oil contamination loading device system, an electromagnetic interference loading device system, a detection system, and a control system.

[0088] The three-dimensional test chamber 84 is equipped with a working platform 79 on each of its left and right sides, both of which are placed flat on the ground;

[0089] The aforementioned grating sensing component system includes: an encoder rotation test device and a grating ruler linear test device, which are placed horizontally adjacent to each other;

[0090] The encoder rotation test device includes: encoder rotation profile mounting frame, encoder support frame 8, encoder 10, flange connecting shaft 11, expansion sleeve 13, and gearbox 14;

[0091] The encoder rotary profile mounting bracket includes a front upper panel 6 and a base plate 1 arranged in parallel and vertically, connected by a profile; the base plate 1 is horizontally fixed above the vibration table of the three-dimensional test chamber 84.

[0092] The encoder support frame 8 has eight parts, four on each side of the gearbox 14, and is fixed to the front upper panel 6 by hexagonal screws 7.

[0093] The encoder support frame 8 is provided with an expansion sleeve 13. The encoder 10 is connected to the expansion sleeve 13 by the flange connecting shaft 11 and the encoder screw 12. The encoder 10 is connected to the encoder support frame 8 by the support frame screw 9.

[0094] The gearbox 14 includes a deep groove ball bearing 29, an upper body 41, a lower body 42, a small end cover 43, a large end cover 44, a gearbox output shaft 47, a gearbox input shaft 48, a helical gear 1 49, and a helical gear 2 50.

[0095] The upper body 41 and the lower body 42 are fixedly connected, wherein the lower body 42 is fixedly connected to the front upper panel 6;

[0096] There are four gearbox output shafts 47, with parallel axes running through the machine body from left to right. Small end caps 43 are provided at the connection points of the upper machine body 41 and the lower machine body 42, which are fixed to the machine body.

[0097] The two ends of the gearbox output shaft 47 are connected to the two side expansion sleeves 13 respectively, and the middle part of the shaft is connected to the No. 2 helical gear 50 through a flat key.

[0098] The gearbox input shaft 48 is provided in one way, which is parallel to the axis of the gearbox output shaft 47, passes through the upper body 41 and the lower body 42, and is provided with a large end cap 44 fixedly connected to the body at the connection point.

[0099] The gearbox input shaft 48 is connected to the No. 1 helical gear 49 via a flat key. The helical gears mesh with each other. One end of the gearbox input shaft 48 can be used as input to drive all gearbox output shafts 47 to rotate simultaneously.

[0100] The other output end of the gearbox input shaft 48 serves as the input end of the grating ruler linear test device.

[0101] Inside the machine body, deep groove ball bearings 29 are provided on both sides of the gearbox output shaft 47 and gearbox input shaft 48, and the deep groove ball bearings 29 are placed on the groove of the end cover of the lower machine body 42.

[0102] The linear testing device for the grating ruler includes: a linear profile mounting bracket for the grating ruler, a lead screw slide assembly, a high and low temperature servo electric cylinder 27, an electric cylinder support base 33, a grating ruler fixing base 53, a grating ruler 54, a proximity switch 61, a proximity switch bracket 62, a corner pyramid prism 64, an L-shaped frame 65, and an end panel 66.

[0103] The linear profile mounting bracket for the grating ruler includes a rear upper panel 51 arranged parallel to the base plate 1, and a profile frame structure between the two.

[0104] The other output end of the gearbox input shaft 48 is connected to the ball screw 24 in the screw slide assembly via the screw coupling 16, so as to transmit power to the linear test device of the grating ruler.

[0105] The lead screw slide assembly is fixed on the rear upper panel 51, and includes a ball screw 24, a lead screw nut 25, and a T-shaped platform 26.

[0106] The rotation of the ball screw 24 can drive the screw nut 25 on it to move back and forth along the guide rail. The screw nut 25 is fixedly connected to the T-shaped platform 26.

[0107] There are four grating ruler fixing seats 53, all parallel to the axis of the ball screw 24, distributed in pairs on the left and right sides of the ball screw 24, and fixed to the rear upper panel 51 by M4x20 internal hex screws.

[0108] Four grating rulers 54 are provided, which are respectively provided on the side end faces of four grating ruler fixing seats 53. The lower part of the grating ruler 54 is fixed to the grating ruler fixing seat 53 by an M8x20 internal hex screw.

[0109] The upper reading head side face of the grating ruler 54 is provided with an L-frame 55. One end of the L-frame 55 is fixed to the upper reading head of the grating ruler 54 by an M4x22 internal hex screw and an M4 nut; the other end of the L-frame 55 is fixed to the T-shaped platform 26 by an M2x8 internal hex screw.

[0110] Two electric cylinder support seats 33 are provided, symmetrically distributed on the left and right, and are fixed to the rear upper panel 51 by M4x16 internal hex screws.

[0111] The high and low temperature servo electric cylinder 27 is mounted on two electric cylinder support seats 33 and is fixed to the two electric cylinder support seats 33 by M8x20 internal hex screws. In this embodiment, the high and low temperature servo electric cylinder 27 of the Kingston VB series is used. One end face of the high and low temperature servo electric cylinder coincides with the right end face of the T-shaped platform 26 and is fixed to the T-shaped platform 26 by M8x20 internal hex screws.

[0112] Two proximity switch brackets 62 are provided, which are fixed to the No. 5 profile 36 by T-nuts M4 and hexagonal screws M4x8. One of them is located at the starting point of the travel of the T-platform 26, and the other is located at the ending point of the travel of the T-platform 26.

[0113] Two proximity switches 61 are provided, each mounted on one of two proximity switch brackets 62. Each proximity switch 61 is connected to the proximity switch bracket 62 via two upper and lower proximity switch nuts 60.

[0114] The L-shaped frame 65 is provided on the left end face of the T-shaped platform 26 and is fixed to the T-shaped platform 26 by a hexagonal screw 7; the corner prism 64 is provided in the groove above the L-shaped frame 65.

[0115] The power transmission device system includes: a synchronous AC servo motor 67 (Panasonic A6 series), a power bearing housing 68, a power coupling 69, a power transmission stepped shaft 70, a bearing housing pad 71 (No. 1), and a bearing housing pad 72 (No. 2).

[0116] The No. 1 bearing seat pad 71 is fixed to the upper part of the left working platform 79 by an M8x20 internal hex screw. A power bearing seat 68 is provided above it, and the power bearing seat 68 is fixed to the No. 1 bearing seat pad 71 by an M8x12 internal hex screw.

[0117] The No. 2 bearing seat pad 72 is provided and is fixed to the front upper panel 6 by an M8x20 hex socket screw; above the No. 2 bearing seat pad 72, there is another power bearing seat 68, which is fixed to the No. 2 bearing seat pad 72 by an M8x12 hex socket screw.

[0118] Each of the power bearing housings 68 is equipped with two deep groove ball bearings 29.

[0119] The power transmission stepped shaft 70 is provided and is located between two power bearing seats 68. The two positioning shoulders of the power transmission stepped shaft 70 coincide with the side end faces of the two power bearing seats 68. The left end face of the three-dimensional test chamber 84 has a shaft hole through which the power transmission stepped shaft 70 passes.

[0120] The synchronous AC servo motor 67 is located above the left working platform 79;

[0121] The output shaft of the synchronous AC servo motor 67 is connected to the left end of the power transmission stepped shaft 70 via a power coupling 69, and the right end of the power transmission stepped shaft 70 is connected to the gearbox input shaft 48 via another power coupling 69.

[0122] The oil pollution loading device system includes: an oil storage tank 73, an oil suction pipe 74, a liquid metering pump 75, an oil discharge pipe 76, a pipe fixing block 77, and a pneumatic full-cone atomizing nozzle 78.

[0123] The oil storage tank 73 is located below the left working platform 79 and is placed on the ground;

[0124] The liquid metering pump 75 (KNF SIMDOS 02 FEM 1.02 S) is located above the left working platform 79. The liquid metering pump 75 has an oil suction pipe 74 at its oil suction port, and the other end of the oil suction pipe 74 is connected to the oil storage tank 73.

[0125] The oil drain pipe 76 is connected at one end to the oil drain port of the liquid metering pump 75; the other end is located inside the three-dimensional test chamber 84 and is fixed to the left end face of the three-dimensional test chamber 84 by the pipe fixing block 77 and the internal hexagon screw M8x20.

[0126] The left end face of the three-dimensional test chamber 84 has a pipe hole, through which the oil drain pipe 76 passes;

[0127] The pneumatic full-cone atomizing nozzle 78 (IKEUCHI JJA series) is provided in two, which are connected to the oil drain pipe 76 at one end inside the three-integrated test chamber 84. One of them is located above the encoder rotation test device, and the other is located above the grating ruler linear test device.

[0128] The electromagnetic interference loading device system includes: a CDN coupling / decoupling network 80, a function generator 81, and a signal line 82;

[0129] The function generator 81 (RIGOL DG1022Z) is located above the right working platform 79. The CDN coupling / decoupling network 80 (TESEQ CDN M216 1kV CDN) is fixed above the right working platform 79 by an M8x20 hex screw and is located between the power supply of the grating sensing component and the grating sensing component.

[0130] The input terminal of the EUT side of the CDN coupling / decoupling network 80 is connected to the DC+ and DC- lines of the power supply for the grating sensing component.

[0131] The function generator 81 has a signal line 82 at its output port, and the other end of the signal line 82 is connected to the RF port of the CDN coupling / decoupling network 80. The output of the CDN coupling / decoupling network 80 leads out a DC+ output line and a DC- output line, which are respectively connected to the power supply terminals of the encoder 10 and the grating ruler 54.

[0132] The detection system includes: a control console 83, a laser interferometer 85, an RTD temperature sensor 86, a triaxial piezoelectric accelerometer 87, an NI synchronous acquisition card 88, a chassis 89, a monitoring platform 90, an oil pollution monitoring unit 91, and an electromagnetic interference detection unit 92.

[0133] The control console 83 is located outside the right-side work platform 79 and is used for setting test parameters, starting the test, monitoring operation, managing data, and recording fault information.

[0134] The laser interferometer 85 is located outside the three-dimensional test chamber 84 and is used to perform high-precision detection and calibration of the displacement accuracy, position feedback accuracy and installation status of the grating ruler linear test device.

[0135] Multiple RTD temperature sensors 86 are provided and are installed inside the three-dimensional test chamber 84 at key positions near the encoder 10 and the grating ruler 54, for real-time monitoring of the actual temperature changes experienced by the test piece.

[0136] The RTD temperature sensor 86 uses a three-wire connection method, and its electrical wires are connected using shielded twisted-pair cable.

[0137] The triaxial piezoelectric accelerometer 87 (Donghua Test 1A314E) is provided in multiple sets, which are respectively installed on the front upper panel 6 and the rear upper panel 51, and are used to collect the X, Y and Z triaxial vibration response signals of the test piece during the test.

[0138] Multiple NI synchronous acquisition cards 88 (PXIe-4499) are installed in the chassis 89 (PXIe-1085) and are used for multi-channel high-precision synchronous acquisition of grating signals, vibration signals, temperature signals, position signals and force feedback signals.

[0139] The monitoring platform 90 is electrically connected to the synchronous acquisition card 88, and performs real-time display, processing, storage, and fault determination of the feedback signals from each sensor and the test piece.

[0140] The monitoring platform 90 includes: a grating signal monitoring module 901, a vibration signal monitoring module 902, a position signal monitoring module 903, and a temperature signal monitoring module 904;

[0141] The grating signal monitoring module 901 is used to acquire the original A / B phase signals output by the grating sensing component in real time, and display the original waveform, the filtered waveform, and the Lissajous figure.

[0142] The vibration signal monitoring module 902 is used to display the X, Y, and Z-axis acceleration waveforms and spectrum information in real time.

[0143] The position signal monitoring module 903 is used to monitor and record the position feedback value of the grating ruler 54 and the angle feedback value of the encoder 10;

[0144] The temperature signal monitoring module 904 is used to display and record temperature data in real time during the test, and to monitor the temperature distribution of key measuring points in the three-dimensional test chamber 84.

[0145] The oil pollution detection unit 91 includes: a flow sensor 911, a pressure sensor 912, and a pollution status judgment module 913;

[0146] The flow sensor 911 is installed on the oil drain pipe 76 to detect the flow rate of the oily medium and determine whether the oil supply status of the liquid metering pump 75 is normal.

[0147] The pressure sensor 912 is installed at the outlet of the liquid metering pump 75 to detect the oil spray pressure and determine whether the spray pressure and atomization state of the pneumatic full-cone atomizing nozzle 78 meet the set requirements.

[0148] The pollution status judgment module 913 is electrically connected to the flow sensor 911, the pressure sensor 912, and the monitoring platform 90, respectively. It is used to determine whether the oil pollution loading has reached the set level based on the flow and pressure information, and to record the duration and degree of oil pollution. Combined with the amplitude, contrast, DC drift, and Lissajous figure changes of the A / B phase signal output by the grating signal monitoring module 901, it indirectly judges the optical path obstruction, signal attenuation, and signal distortion caused by oil pollution.

[0149] The electromagnetic interference detection unit 92 includes: a voltage detection module 921, an interference signal monitoring module 922, and an electromagnetic response judgment module 923;

[0150] The voltage detection module 921 is located at the output of the CDN coupling / decoupling network 80 and is used to detect interference voltage signals injected into the power supply circuits of the encoder 10 and the grating ruler 54.

[0151] The interference signal monitoring module 922 is electrically connected to the function generator 81 and the CDN coupling / decoupling network 80 respectively, and monitors the amplitude, frequency, waveform and injection duration of the interference signal;

[0152] The electromagnetic response judgment module 923 is electrically connected to the monitoring platform 90. Based on the fluctuation of the A / B phase output signal, abnormal position feedback, signal interruption, etc., it judges the degree of impact of electromagnetic interference on the performance of the grating sensing component.

[0153] The control system includes: an STM32 microcontroller 93, a differential pulse transmission module 94, a servo motor driver 95, a servo motor encoder 96, a digital-to-analog converter module 97, a servo electric cylinder driver 98, a force sensor 99, and an isolation interface module 100.

[0154] The STM32 microcontroller 93 (F446RE) is used as the core control unit of the control system to realize the position or speed control of the synchronous AC servo motor 67 and the dynamic force control of the high and low temperature servo electric cylinder 27.

[0155] The differential pulse transmission module 94 is electrically connected to the STM32 microcontroller 93 and is used to transmit position control commands to the servo motor driver 95 in the form of differential pulse signals.

[0156] The servo motor driver 95 is electrically connected to the synchronous AC servo motor 67 and is used to receive the pulse signal output by the STM32 microcontroller 93 and drive the synchronous AC servo motor 67 to operate.

[0157] The servo motor encoder 96 is mounted on the synchronous AC servo motor 67 and is used to detect the output speed of the synchronous AC servo motor 67 in real time and transmit the feedback signal to the STM32 microcontroller 93 to form closed-loop control.

[0158] The digital-to-analog converter module 97 is electrically connected to the STM32 microcontroller 93 and is used to convert the digital signal output by the control algorithm into an analog voltage signal and output it to the servo electric cylinder driver 98.

[0159] The servo cylinder driver 98 is electrically connected to the high and low temperature servo cylinder 27, and is used to receive the analog voltage signal output by the control system and control the high and low temperature servo cylinder 27 to apply transient impact load.

[0160] Multiple force sensors 99 are provided and are located on the force transmission path of the high and low temperature servo cylinder 27. They are used to detect the impact force output by the high and low temperature servo cylinder 27 in real time and transmit the feedback signal to the STM32 microcontroller 93 to form closed-loop control.

[0161] The isolation interface module 100 is disposed between the control system and the external actuator to achieve isolation between the control system and the detection system in terms of physical connection and electrical control.

[0162] The control system is used to coordinate the coordinated actions of the synchronous AC servo motor 67, the high and low temperature servo cylinder 27, the three-comprehensive test chamber 84, the oil pollution loading device system and the electromagnetic interference loading device system, so as to realize the automatic control of reliability testing under multiple stress conditions such as temperature, humidity, vibration, shock, oil pollution and electromagnetic interference.

[0163] The control system and the detection system are independent of each other in terms of hardware platform and electrical connection, and adopt differential signal transmission, shielded cables and isolation interface measures to ensure the stability, reliability and anti-interference ability of the control process under complex stress environment.

[0164] The lead screw slide assembly includes: a bearing mounting base 20, a front lead screw support base 23, a ball screw 24, a lead screw nut 25, a T-shaped platform 26, a rear lead screw support base 28, a connecting block 52, and a guide rail 58.

[0165] The front lead screw support 23 is fixed to the rear upper panel 51 by an internal hex screw 7, and a bearing fixing seat 20 is provided inside it; an oil seal 22 is provided on the right end face of the bearing fixing seat 20, and two angular contact ball bearings 21 are provided inside; an adjusting ring 18 and a bearing cover 19 are provided on the left end face, and a fastening nut 17 is provided between it and the coupling 16.

[0166] The rear lead screw support 28 is fixedly connected to the rear upper panel 51 via the connecting block 52. It is equipped with a deep groove ball bearing 29 and a snap ring 30 inside, and the right end face is fixed to the lead screw end cover 32 via the lead screw end cover screw 31.

[0167] The ball screw 24 is installed between the front screw support 23 and the rear screw support 28. The ball screw 24 is an external circulation ball screw manufactured by THK.

[0168] The lead screw nut 25 forms a threaded pair with the ball screw 24 and is mounted thereon. The lead screw nut 25 is fixed to the T-shaped platform 26 by screws.

[0169] The guide rail 58 is arranged parallel to the axis of the ball screw 24 and is mounted on the rear upper panel 51 through the guide rail base 57. The guide rail 58 is fixed to the guide rail base 57 by an M3x18 internal hex screw.

[0170] The guide rail 58 is slidably connected to the upper part of the adjustment block 59, and the adjustment block 59 is fixed to the T-shaped platform 26 by an M4x30 internal hex screw; the right end face of the adjustment block 59 is provided with a T-shaped extrusion block 56, and the T-shaped extrusion block 56 is fixed to the T-shaped platform 26 by an M3x20 internal hex screw.

[0171] The encoder rotary profile mounting bracket consists of a base plate 1, profile 1 2, profile 2 38, profile 3 63, corner piece 3, and front upper panel 6;

[0172] The No. 1 profile 2 is provided in four strips, which are parallel to each other and distributed at four corners. The No. 1 profile 2 is fixed to the base plate 1 by M6x16 internal hex screws and is set perpendicular to the base plate 1.

[0173] The front upper panel 6 is fixed to the upper end of the four No. 1 profiles 2 by M6x16 socket head cap screws;

[0174] The No. 2 profile 38 is provided in four strips. The four No. 2 profiles 38 are parallel to each other and parallel to the base plate 1. The two pairs of No. 2 profiles 38 are fixed to the two sets of No. 1 profiles 2 set on the left and right by internal hexagon flat round head screws 35, and are fixed to the upper and lower ends of the No. 1 profiles 2 respectively.

[0175] The No. 3 profile 63 is provided in four strips. The four No. 3 profiles 63 are parallel to each other and parallel to the base plate 1. The two pairs of No. 3 profiles 63 are fixed to the two sets of No. 1 profiles 2 arranged in front and behind by internal hexagon flat round head screws 35, and are respectively fixed to the upper and lower ends of the No. 1 profiles 2.

[0176] The corner piece 3 is provided at each profile-to-profile connection and is fixed to the profile by T-bolt 4 and nut 5.

[0177] The gearbox 14 also includes a breather 39, an inspection port cover 40, a screw plug 45, and an oil dipstick 46;

[0178] One ventilator 39 and one inspection hole cover 40 are provided and fixed to the upper body 41 by screws. A gasket is provided between the inspection hole cover 40 and the upper body 41.

[0179] The screw plug 45 is connected to the lower body 42 via a threaded connection; the oil dipstick 46 is placed inside the oil level hole of the lower body 42.

[0180] The lower body 42 is fixedly connected to the front upper panel 6 by gearbox screws 15, and the upper body 41 is fixedly connected to the lower body 42 by bolts and nuts;

[0181] There are 8 small end caps 43, with 4 on each side of the gearbox 14, arranged symmetrically and coinciding with the axis of the gearbox output shaft 47, and fixed to the upper body 41 and the lower body 42 by screws.

[0182] Two large end caps 44 are provided, one on each side of the gearbox 14, symmetrically arranged and coinciding with the axis of the gearbox input shaft 48, and are fixed to the upper body 41 and the lower body 42 by screws.

[0183] The linear profile mounting bracket for the grating ruler is composed of profile 63 (No. 3), profile 34 (No. 4), profile 36 (No. 5), profile 37 (No. 6), corner piece 3, and upper rear panel 51.

[0184] The No. 4 profile 34 is provided in four parallel sections, arranged at four corners. The No. 4 profile 34 is fixed to the base plate 1 by M6x16 hex socket screws and is set perpendicular to the base plate 1. Two of the No. 4 profiles 34 are adjacent to the No. 1 profile 2. The outer sides of the adjacent No. 4 profiles 34 and No. 1 profile 2 are provided with end panels 66. The end panels 66 are connected to the No. 4 profiles 34 and No. 1 profile 2 by M4x8 hex socket screws and M4 T-nuts.

[0185] The rear upper panel 51 is fixed to four No. 4 profiles 34 by M6x16 socket head cap screws;

[0186] The No. 5 profile 36 is provided in four strips. The four No. 5 profiles 36 are parallel to each other and parallel to the base plate 1. The two pairs of No. 5 profiles 36 are fixed to the two sets of No. 4 profiles 34 arranged on the left and right by internal hexagon flat round head screws 35, and are respectively fixed to the upper and lower ends of the No. 4 profiles 34.

[0187] The No. 6 profile 37 is provided in two pairs. The two No. 6 profiles 37 are parallel to each other and perpendicular to the base plate 1. The two No. 6 profiles 37 are fixed to the front and rear two pairs of No. 5 profiles 36 respectively by internal hexagon flat round head screws 35, and are located between the two No. 5 profiles 36.

[0188] This mounting bracket has six No. 3 profiles 63, all of which are parallel to the base plate 1. Two pairs of No. 3 profiles 63 are fixed to the two sets of No. 4 profiles 34 set in front and behind by internal hexagonal flat round head screws 35, and are respectively fixed to the upper and lower ends of the No. 4 profiles 34.

[0189] Another pair of No. 3 profiles 63 are located between two No. 6 profiles 37. The corner pieces 3 are located at the connection between each profile and are fixed to the profile by T-bolts 4 and nuts 5.

[0190] Example 2:

[0191] The dynamic reliability test method for multi-stress coupling of grating sensing components adopts the method of the dynamic reliability test bench for multi-stress coupling of grating sensing components described in Example 1 above, and proposes a set of reliability test methods for the grating sensing components (encoder and grating ruler) under test.

[0192] See appendix Figure 14 The dynamic reliability test method for multi-stress coupling of grating sensing components, the specific steps are as follows:

[0193] S1. Reliability Test Preparation:

[0194] 1) Ensure that the test environment meets the set conditions, and place the grating sensing component multi-stress coupling dynamic reliability test bench in the test environment for pre-stabilization for no less than 12 hours;

[0195] 2) Set stress parameters such as temperature, humidity, vibration and impact in the control system. Temperature, humidity and vibration stress are applied by the three-comprehensive test chamber 84, and impact stress is applied by the high and low temperature servo electric cylinder 27.

[0196] 3) Set the impact loading force, loading frequency and loading waveform of the high and low temperature servo electric cylinder 27 in the control system. The loading waveform mainly includes linear wave, trapezoidal wave, sine wave, triangular wave, square wave and random wave, and ensure that the cylinder rod of the high and low temperature servo electric cylinder 27 is fully extended.

[0197] 4) Set the oil contamination loading parameters (spraying time, spraying flow rate, and contaminant concentration) according to the actual service environment of the test piece, start the oil contamination loading module, and apply the contaminant to the grating ruler reading head area, encoder mounting edge, and related transmission parts. The contaminant includes lubricating oil, cutting fluid, oil mist mixture, etc.

[0198] 5) Set the electromagnetic interference parameters (interference frequency, amplitude, pulse width, repetition frequency, injection time) according to the actual service environment of the test device, start the electromagnetic interference module, and apply electromagnetic disturbance to the power supply line of the test device through the TESEQ CDN M216 1kV CDN coupling / decoupling network 80 and RIGOL DG1022Z function generator 81.

[0199] 6) Set the motion mode of servo motor 67 in the control system so that the linear encoder test device performs reciprocating linear motion and the encoder rotation test device performs continuous rotational motion.

[0200] 7) By adjusting the position of proximity switch 61, a corresponding limit relationship is formed between it and the moving parts, ensuring that the linear test device of the grating ruler operates within the specified stroke range;

[0201] 8) Adjust the positions of each mounting component in the linear test device and the rotary test device of the grating ruler, and install the grating sensing component to be tested in the corresponding position on the test bench. The grating ruler 54 is installed on the grating ruler fixing base 53, and the encoder 10 is installed on the encoder support frame 8.

[0202] 9) Turn on the detection and control systems, and calibrate the laser interferometer 85, RTD temperature sensor 86, triaxial piezoelectric accelerometer 87 and grating signal acquisition channel to ensure that each detection unit is in normal working condition.

[0203] 10) Set the failure judgment threshold of the grating sensing component. The failure judgment threshold includes the signal amplitude threshold, signal interruption threshold, signal stability threshold, signal equal amplitude threshold, temperature rise threshold, abnormal vibration threshold, and the limit displacement threshold of the grating ruler 54 and the T-shaped platform 26.

[0204] S2. Detection and recording of reliability test data:

[0205] 1) Start the automatic control program; the reliability test begins timing.

[0206] 2) The three-dimensional test chamber 84 applies temperature, humidity and vibration environmental stress according to the set program, while the high and low temperature servo electric cylinder 27 applies mechanical impact stress to the test piece according to the set waveform, frequency and load; the synchronous AC servo motor 67 drives the encoder rotation test device and the grating ruler linear test device to run continuously.

[0207] 3) The detection system acquires the A-phase, B-phase, and Z-phase signals output by the grating ruler 54 in real time, and measures their signal amplitude, phase relationship, waveform stability, and position feedback value; at the same time, the laser interferometer 85 measures the actual value of the linear displacement of the grating ruler 54 and the T-shaped platform 26, and compares it with the limit displacement threshold set by the control system. If the actual value is greater than the set value, the limit displacement accuracy of the grating ruler linear test device is determined to be faulty, and it is recorded as a first accuracy failure fault.

[0208] 4) The detection system acquires the A-phase, B-phase and Z-phase signals output by the encoder 10 in real time, and measures their signal amplitude, phase relationship, waveform stability and angular displacement feedback value; at the same time, the encoder output angular displacement is checked by a high-precision angle measuring device or a standard rotation angle reference value to obtain the angular displacement error. If the angular displacement is greater than the set threshold, the accuracy of the encoder rotation test device is determined to be faulty, and it is recorded as a first accuracy failure fault.

[0209] 5) The detection system synchronously records the type of contaminant, viscosity, particle concentration, spray flow rate, spray duration, spray cycle and cumulative contamination time during the oil pollution loading test, and records the baseline drift, phase difference and signal symmetry of the A-phase, B-phase and Z-phase outputs of the grating ruler 54 and encoder 10 in real time.

[0210] 6) The detection system synchronously records the interference form, interference frequency, injection amplitude, pulse width, repetition frequency and interference duration during the electromagnetic interference test, and records in real time the original A-phase, B-phase and Z-phase signal voltage waveforms, count pulses, number of bit errors, number of false triggers and number of lost pulses output by the grating ruler 54 and encoder 10.

[0211] 7) The RTD temperature sensor 86 measures the temperature change data of the test piece and the test environment in real time and transmits it to the monitoring platform 90; the triaxial piezoelectric accelerometer 87 measures the vibration response signal of the key parts of the test bench and the installation position of the test piece in real time and transmits it to the monitoring platform 90; the monitoring platform 90 compares the collected signals with the various thresholds set in the control system. If any parameter exceeds the preset threshold, it determines that the test piece has experienced a performance degradation or failure fault, and records the fault occurrence time, fault type and corresponding stress conditions.

[0212] 8) The control system automatically plots temperature and humidity-time curves, vibration response-time curves, signal amplitude-time curves, oil flow rate-time curves, and interference voltage-time curves based on the detection data, and saves the original signal data of the grating ruler 54 and encoder 10 during the test. The control system also records other faults that occur during the test, such as: faults in the three-dimensional test chamber, blockage of the oil nozzle, abnormal electromagnetic interference injection, and alarms in the control system. If a fault occurs, the reliability test is stopped, and the continuous fault-free working time of the test is recorded.

[0213] S3. Analysis of Reliability Test Data:

[0214] 1) After the reliability test is completed, the fault data collected during the test is statistically analyzed and processed. The mean time between failures (MTBF) of the grating sensing component is calculated using time-truncated test data, and the reliability is assessed in conjunction with the 90% confidence interval. First, the MTBF point estimate is calculated based on the total effective test time and the total number of associated failures. Then, the two-sided or one-sided confidence interval is estimated based on whether the number of associated failures is greater than 0. When the MTBF point estimate is not lower than the specified index and the confidence interval results meet the requirements, the reliability of the grating sensing component is determined to meet the requirements.

[0215] 2) After the reliability test is completed, the temperature and humidity-time curves, vibration response-time curves, signal amplitude-time curves, oil flow rate-time curves, and interference voltage-time curves collected during the test are analyzed to obtain the performance degradation law of the grating sensing component under multi-stress coupling; combined with the environmental stress parameters, mechanical stress parameters, and grating signal waveforms corresponding to the fault occurrence, the fault mechanism is analyzed and the weak link is located.

[0216] 3) If any faults occur during the reliability test, such as failure of the three-integrated test chamber, blockage of the oil nozzle, abnormal injection of electromagnetic interference, or alarm of the control system, the test should be stopped immediately, the cause of the fault should be analyzed, and the multi-stress coupling dynamic reliability test bench for the grating sensing component should be improved.

Claims

1. A dynamic reliability test bench for multi-stress coupling of grating sensing components, characterized in that, include: Work platform (79), three-dimensional test chamber (84), grating sensing component device system, power transmission device system, oil pollution loading device system, electromagnetic interference loading device system, detection system, control system; The three-dimensional test chamber (84) is equipped with a working platform (79) on each of its left and right sides. The aforementioned grating sensing component system includes: an encoder rotation test device and a grating ruler linear test device, which are placed horizontally adjacent to each other; The power transmission device system is connected to the encoder rotation test device, and the encoder rotation test device is connected to the grating ruler linear test device. The encoder rotation test device includes an encoder rotation profile mounting bracket, an encoder support bracket (8), an encoder (10), a flange connecting shaft (11), an expansion sleeve (13), and a gearbox (14). The encoder rotating profile mounting bracket includes a front upper panel (6) and a base plate (1) arranged in parallel and vertically, which are connected by profiles; the base plate (1) is horizontally fixed above the vibration table of the three-dimensional test chamber (84); The encoder support frame (8) is fixed to the front upper panel (6) by internal hexagon screws (7). An expansion sleeve (13) is provided inside the encoder support frame (8). The encoder (10) is connected to the expansion sleeve (13) by the flange connecting shaft (11) and the encoder screw (12). The gearbox (14) includes a deep groove ball bearing (29), an upper body (41), a lower body (42), a small end cover (43), a large end cover (44), a gearbox output shaft (47), a gearbox input shaft (48), a helical gear No. 1 (49), and a helical gear No. 2 (50). The upper body (41) is fixedly connected to the lower body (42), and the lower body (42) is fixedly connected to the front upper panel (6); the two ends of the gearbox output shaft (47) are connected to the expansion sleeve (13), and the gearbox input shaft (48) drives the gearbox output shaft (47) to rotate through the meshing of the No. 1 helical gear (49) and the No. 2 helical gear (50); one end of the gearbox input shaft (48) is connected to the power transmission device system, and the other end is connected to the linear test device of the grating ruler.

2. The dynamic reliability test bench for multi-stress coupling of grating sensing components according to claim 1, characterized in that: The linear test device for the grating ruler includes a linear profile mounting bracket for the grating ruler, a lead screw slide assembly, a high and low temperature servo electric cylinder (27), an electric cylinder support base (33), a grating ruler fixing base (53), a grating ruler (54), a proximity switch (61), a proximity switch bracket (62), a corner pyramid prism (64), an L-shaped frame (65), and an end panel (66). The linear profile mounting bracket for the grating ruler includes a rear upper panel (51) arranged parallel to the base plate (1) and a profile frame between the two; The gearbox input shaft (48) is connected to the ball screw (24) of the screw slide assembly via the screw coupling (16) to transmit power to the linear test device of the grating ruler. The ball screw slide assembly is fixed on the rear upper panel (51) and includes a ball screw (24), a ball screw nut (25), and a T-shaped platform (26). The grating ruler mounting base (53) is fixed on the rear upper panel (51), the grating ruler (54) is installed on the grating ruler mounting base (53), and the reading head of the grating ruler (54) is fixed to the T-shaped platform (26) through the L-frame (55); The high and low temperature servo electric cylinder (27) is fixed on the rear upper panel (51) through the electric cylinder support base (33) and is fixedly connected to the T-shaped platform (26); The proximity switch bracket (62) and the proximity switch (61) are respectively set at both ends of the travel of the T-shaped platform (26); the corner cube prism (64) is installed on the T-shaped platform (26) through the L-shaped bracket (65).

3. The dynamic reliability test bench for multi-stress coupling of grating sensing components according to claim 2, characterized in that: The power transmission device system includes a synchronous AC servo motor (67), a power bearing housing (68), a power coupling (69), a power transmission stepped shaft (70), a bearing housing pad No. 1 (71), and a bearing housing pad No. 2 (72). The No. 1 bearing seat pad (71) is fixed to the left working platform (79), and the No. 2 bearing seat pad (72) is fixed to the front upper panel (6); the power bearing seat (68) is installed on the No. 1 bearing seat pad (71) and the No. 2 bearing seat pad (72) respectively, and the power bearing seat (68) is equipped with a deep groove ball bearing (29). The power transmission stepped shaft (70) passes through the shaft hole of the three-dimensional test chamber (84), and its two ends are respectively connected to the output shaft of the synchronous AC servo motor (67) and the input shaft of the gearbox (48) through the power coupling (69).

4. The dynamic reliability test bench for multi-stress coupling of grating sensing components according to claim 3, characterized in that: The oil pollution loading device system includes an oil storage tank (73), an oil suction pipe (74), a liquid metering pump (75), an oil discharge pipe (76), a pipe fixing block (77), and a pneumatic full-cone atomizing nozzle (78). The oil storage tank (73) is located below the left working platform (79), and the liquid metering pump (75) is located above the left working platform (79); The oil suction pipe (74) connects the oil storage tank (73) to the oil suction port of the liquid metering pump (75), and the oil discharge pipe (76) passes through the pipe hole of the three-dimensional test chamber (84) and is fixed by the pipe fixing block (77); The pneumatic full-cone atomizing nozzle (78) is located at one end of the oil drain pipe (76) inside the three-comprehensive test chamber (84), corresponding to the encoder rotation test device and the grating ruler linear test device respectively.

5. The dynamic reliability test bench for multi-stress coupling of grating sensing components according to claim 4, characterized in that: The electromagnetic interference loading device system includes a CDN coupling / decoupling network (80), a function generator (81), and a signal line (82). The function generator (81) and the CDN coupling / decoupling network (80) are located above the right-side work platform (79); The CDN coupling / decoupling network (80) is connected to the power supply of the grating sensing component. The function generator (81) is connected to the RF port of the CDN coupling / decoupling network (80) through the signal line (82). The output of the CDN coupling / decoupling network (80) is connected to the power supply of the encoder (10) and the grating ruler (54).

6. The dynamic reliability test bench for multi-stress coupling of grating sensing components according to claim 5, characterized in that: The detection system includes a control console (83), a laser interferometer (85), an RTD temperature sensor (86), a triaxial piezoelectric accelerometer (87), an NI synchronous acquisition card (88), a chassis (89), a monitoring platform (90), an oil pollution monitoring unit (91), and an electromagnetic interference detection unit (92). The monitoring platform (90) includes a grating signal monitoring module (901), a vibration signal monitoring module (902), a position signal monitoring module (903), and a temperature signal monitoring module (904). The oil pollution monitoring unit (91) includes a flow sensor (911), a pressure sensor (912), and a pollution status judgment module (913). The electromagnetic interference detection unit (92) includes a voltage detection module (921), an interference signal monitoring module (922), and an electromagnetic response judgment module (923).

7. The dynamic reliability test bench for multi-stress coupling of grating sensing components according to claim 6, characterized in that: The control system includes an STM32 microcontroller (93), a differential pulse transmission module (94), a servo motor driver (95), a servo motor encoder (96), a digital-to-analog converter module (97), a servo electric cylinder driver (98), a force sensor (99), and an isolation interface module (100). The STM32 microcontroller (93) is connected to the servo motor driver (95) through the differential pulse transmission module (94), and the servo motor driver (95) drives the synchronous AC servo motor (67). The servo motor encoder (96) feeds back the signal to the STM32 microcontroller (93). The STM32 microcontroller (93) is connected to the servo cylinder driver (98) through the digital-to-analog converter module (97), and the servo cylinder driver (98) drives the high and low temperature servo cylinder (27). The force sensor (99) collects the output force of the high and low temperature servo electric cylinder (27) and feeds it back to the STM32 microcontroller (93). The control system and the detection system are electrically isolated through the isolation interface module (100).

8. The dynamic reliability test bench for multi-stress coupling of grating sensing components according to claim 7, characterized in that: The lead screw slide assembly also includes a bearing mounting base (20), a front lead screw support base (23), a rear lead screw support base (28), a connecting block (52), a guide rail base (57), a guide rail (58), an adjusting block (59), and a T-shaped extrusion block (56). The front lead screw support (23) is fixed to the rear upper panel (51), and the interior is provided with a bearing fixing seat (20), an angular contact ball bearing (21), an oil seal (22), an adjusting ring (18), and a bearing cover (19). The rear lead screw support (28) is fixed to the rear upper panel (51) by a connecting block (52), and a deep groove ball bearing (29), a snap ring (30) and a lead screw end cap (32) are installed inside. The guide rail (58) is fixed to the rear upper panel (51) via the guide rail base (57). The guide rail (58) is slidably connected to the adjustment block (59), and the adjustment block (59) is fixedly connected to the T-shaped platform (26).

9. A method for dynamic reliability testing of multi-stress coupling in a grating sensing component, characterized in that: The multi-stress coupling dynamic reliability test bench for the grating sensing component as described in claim 8 includes the following steps: S1 test preparation: After the test bench is pre-stabilized, the temperature and humidity, vibration parameters, impact parameters of the high and low temperature servo electric cylinder (27), oil contamination parameters of the pneumatic full cone atomizing nozzle (78) and electromagnetic interference parameters of the CDN coupling / decoupling network (80) are set through the control system. Set the motion mode of the synchronous AC servo motor (67), adjust the proximity switch (61) to form a limit; mount the grating ruler (54) on the grating ruler mounting base (53) and the encoder (10) on the encoder support frame (8); calibrate the laser interferometer (85), RTD temperature sensor (86), and triaxial piezoelectric accelerometer (87), and set the failure judgment threshold; S2 test operation: Start the test, apply environmental stress to the three comprehensive test chamber (84), apply coaxial impact load to the high and low temperature servo electric cylinder (27), drive the specimen to move with the synchronous AC servo motor (67), and simultaneously load oil and electromagnetic interference; S3 Data Acquisition: The NI synchronous acquisition card (88) and the monitoring platform (90) acquire grating signals, displacement / angle, temperature and vibration data in real time, compare them with the calibration value of the laser interferometer (85), determine the failure and record the fault information; S4 Result Analysis: After the test is completed, the mean time between failures is calculated based on the fault data, the performance degradation law and failure mechanism are analyzed, and the reliability assessment is completed.

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