In-machine measurement device and method for fractal features of gear surfaces and oil film thickness at meshing points in planetary gear trains

Abstract

This invention proposes an in-machine measurement device and method for the fractal features of gear surfaces and the thickness of oil film at meshing points in planetary gear trains, belonging to the field of gear surface inspection. It solves the problem that the thickness of oil film between the sun gear and planet gears in a planetary gear train under lubricated contact is difficult to measure in-machine, affecting service life and stability. The measurement device includes a robotic arm, a magnetic levitation guide rail, a robotic arm base, an optical fiber transmitter, an optical fiber displacement sensor, a visible light laser, and a visible light laser collector. Depending on different work requirements, the robotic arm's multi-functional measuring head can achieve measurement conversion, avoiding data deviation caused by frequent changes in measuring instruments. The magnetic levitation track reduces frictional resistance and vibration during robotic arm movement, making the measurement data more accurate. Combined with a fuzzy adaptive control algorithm for feedback fine-tuning of the robotic arm's movement, it is more suitable for in-machine measurement of oil film thickness.

Description

Technical Field

[0001] This invention belongs to the field of gear surface inspection, and in particular relates to an in-machine measurement device and method for the fractal features of gear surfaces and the thickness of oil film at meshing points. Background Technology

[0002] Due to the high pressure and severe wear between gears under elastohydrodynamic (ELD) contact conditions, establishing an elastohydrodynamic lubrication model and constructing an elastohydrodynamic lubrication theory presents significant challenges. Therefore, new measurement methods are needed to measure oil film thickness. Methods for measuring oil film thickness between sun and planetary gears generally fall into three categories: optical interferometry, eddy current method, and capacitance method. Optical interferometry can achieve nanometer-level accuracy, but requires post-processing of the optical signal. The eddy current method obtains oil film thickness through changes in the sensor signal in the probe, but its measurement speed is relatively slow. The capacitance method is a typical non-contact measurement with good dynamic response, but the capacitance of the sensor is easily affected by external conditions, leading to unstable results.

[0003] Methods for measuring the fractal characteristics of gear surfaces are generally divided into two categories: the template comparison method and the instrument inspection method. The template comparison method involves visually inspecting and comparing the gear with a standard part using a magnifying glass; this method has relatively low accuracy. The instrument inspection method, using an interference microscope and an electric profilometer, allows for micrometer-level microscope precision, resulting in accurate measurement results.

[0004] Planetary gear trains are widely used in mechanical transmissions due to their high transmission efficiency. The meshing state between the sun gear and planet gears plays a crucial role in the accuracy, stability, efficiency, and service life of the planetary gear train. Unstable meshing can lead to failures such as pitting and tooth root fracture, adversely affecting gear life. Gear contact analysis under lubrication conditions is particularly important; therefore, the accuracy of in-machine measurement of the oil film thickness between the sun gear and planet gears, as well as other parameters, is paramount. Summary of the Invention

[0005] To address the challenge of measuring the oil film thickness between the sun gear and planet gears in a planetary gear train under lubricated contact, which affects service life and stability, this invention proposes an in-machine measurement device and method for the fractal features of gear surfaces and the oil film thickness at the meshing point in a planetary gear train.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: an in-machine measuring device for the fractal features of gear surfaces and the oil film thickness at meshing points in a planetary gear train, comprising a robotic arm, a magnetic levitation guide rail, a robotic arm base, an optical fiber transmitter, an optical fiber displacement sensor, a visible light laser, and a visible light laser collector. The robotic arm base is connected to the magnetic levitation guide rail, and the robotic arm is connected to the robotic arm base by positioning bolts. The oil film thickness measuring device and the gear surface fractal feature measuring device are fixed on a multi-functional measuring head at the end of the robotic arm. The four joints of the robotic arm are connected by an internal flange, which is fixed by screws.

[0007] Furthermore, the robotic arm base is connected to the robotic arm via a clamping washer and a positioning bolt.

[0008] Furthermore, the robotic arm is slidably connected to the cast iron T-shaped table slide groove via a magnetic levitation guide rail below the robotic arm base.

[0009] Furthermore, the fiber optic displacement sensor is connected to the head of the robotic arm, the laser transceiver is connected to the head of the robotic arm, and the multi-functional measuring head at the end of the robotic arm is rotatable.

[0010] Furthermore, the movement mode of the robotic arm and the pitch movement of the robotic arm head measuring device are both connected to the user terminal microcomputer via a data port. The user terminal microcomputer controls the movement of the robotic arm through a programmed program.

[0011] Furthermore, both the fiber optic displacement sensor and the visible light laser collector are connected to the data acquisition system via data ports, and the data acquisition system is connected to the user terminal microcomputer via data ports.

[0012] An in-machine method for measuring the fractal features of gear surfaces and the oil film thickness at the meshing point in a planetary gear train, comprising the following steps:

[0013] Step 1: Install and fix the gearbox on the cast iron T-shaped platform, initialize the parameters of the measuring device, power on the magnetic levitation guide rail, and use the fuzzy adaptive control algorithm of the robotic arm motion controller to regulate the movement of the robotic arm so that the entire robotic arm moves to the area to be measured. Then, make adaptive adjustments to the waist joint, shoulder joint, elbow joint, and wrist joint of the robotic arm to reach the area to be measured as soon as possible. After exceeding the area to be measured, the position of the robotic arm is adjusted through feedback control.

[0014] Step Two: The robotic arm can rotate the multi-functional measuring head according to different measurement needs. During the measurement of the fractal features of the gear, the end effector of the robotic arm wrist joint rotates the multi-functional measuring head to switch to the fractal feature measuring device, calibrates the fractal feature measuring device, and the visible light laser starts to work and emit laser light. The robotic arm motion controller controls the robotic arm to rotate smoothly at the gear to be measured times, each time rotating by an angle of degrees. During the rotation, the visible light laser illuminates the gear to be measured, and the laser light collector can collect the reflected light signal and transmit the signal to the user terminal microcomputer through the data acquisition system.

[0015] Step 3: During the measurement of the oil film thickness between the sun gear and planetary gears, the end effector of the robotic arm rotates the multi-functional measuring head to switch to the oil film thickness measuring device. The robotic arm motion controller adjusts the robotic arm to the position to be measured. The fiber optic transmitter emits light signals to the meshing point of the sun gear and planetary gears. The fiber optic displacement sensor collects the light signals reflected back through the oil film. The position of the robotic arm is then finely adjusted by the robotic arm motion controller. The oil film thickness is measured at multiple points. The average value of the measurement results is taken. The light signals are transmitted to the user terminal microcomputer through the data acquisition system.

[0016] Step 4: On the user terminal microcomputer, coordinate transformation is performed using the acquired optical signals. A three-dimensional mathematical model of oil film thickness is established by using the data obtained from the data acquisition system. The three-dimensional mathematical model of oil film thickness is then corrected by combining it with the formula. The measurement data of the fiber optic displacement sensor and the measurement data of the visible light laser collector are read and recorded. The images are then fused to construct a three-dimensional model of oil film thickness.

[0017] Step 5: Reset the robotic arm to its initial position by controlling the robotic arm motion controller.

[0018] Compared with existing technologies, the beneficial effects of this invention are: This invention solves the problem that it is difficult to measure the oil film thickness of the sun gear and planet gears under lubrication contact in existing planetary gear systems, affecting the service life and stability of the planetary gear system. This invention is used for the in-machine measurement of the oil film thickness at the meshing point of the sun gear and planet gears and the reconstruction of the elastohydrodynamic lubrication contact model, thereby improving the working efficiency and stability of the planetary gear system under lubrication contact conditions. The measuring device is based on the principle of optical reflection. By illuminating the surface of the planet gear under test with light emitted from a light source, the signal receiver receives and processes the optical signal, and the user terminal microcomputer analyzes the optical signal to obtain the surface roughness value and oil film thickness information of the planet gear under test, thus realizing the measurement of the oil film thickness data of the sun gear and planet gears under lubrication contact in the planetary gear system. The measurement method integrates fuzzy adaptive control algorithm, fusion data modeling technology, and digital image processing technology to reconstruct a three-dimensional model of the oil film thickness under lubrication contact conditions. A visible light laser and fiber optic transmitter are used to perform full-coverage detection of the surface area and meshing contact area of ​​the sun gear and planet gears. The robotic arm measuring device is designed with 5 degrees of freedom, which can accurately adjust the measurement angle range and the relative position with the area of ​​the planet gear under test. Fiber optic technology is used to measure the oil film thickness at the meshing point of the sun gear and planetary gears, offering advantages such as rapid measurement, high accuracy, and low cost. The use of a magnetic levitation track reduces vibration and frictional resistance during the robotic arm's movement, allowing it to reach the target position more quickly and accurately, resulting in more precise measurement data. A fuzzy adaptive control algorithm is combined to fine-tune the robotic arm's movement, enabling efficient and accurate adjustment of the measured target data. By combining data modeling and digital image processing technologies, the integrity of the acquired data and the accuracy of spatial information are ensured. Post-processing of the data reconstructs a complete model of the oil film thickness in the measured area. Compared to traditional oil film thickness measurement methods, this method achieves faster and more accurate oil film thickness parameter measurement for the planetary gears under test, meeting the needs of precise oil film thickness measurement and online control in industrial processing and scientific research. Compared to other oil film thickness measurement methods, it avoids the system calibration complexity of silicone oil film thickness analyzers and the difficulty in obtaining good measurement results due to the easy wear of measuring instruments in contact surface roughness measurements. The present invention provides corresponding solutions to the above-mentioned shortcomings, and the measurement method is more efficient and faster, with accurate results and low cost. It avoids data deviation caused by frequent replacement of measuring instruments and is more suitable for in-machine measurement of oil film thickness. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating the in-machine measurement method for the fractal features of gear surfaces and the thickness of oil film at meshing points in a planetary gear train, as described in this invention.

[0020] Figure 2This is a flowchart of the in-machine measurement method for fractal features of gear surfaces in a planetary gear train according to the present invention.

[0021] Figure 3 The flowchart shows the in-machine measurement method for oil film thickness at meshing points in a planetary gear train according to the present invention.

[0022] Figure 4 This is a schematic diagram of the in-machine measurement device for measuring the fractal features of the gear surface and the oil film thickness at the meshing point in the planetary gear train according to the present invention.

[0023] Figure 5 This is a schematic diagram of the working structure of the in-machine measurement device system for measuring the fractal features of the gear surface and the oil film thickness at the meshing point in the planetary gear train according to the present invention.

[0024] Figure 6 This is a schematic diagram of the magnetic levitation guide rail structure described in this invention;

[0025] Figure 7 This is a schematic diagram of the in-machine measurement device for oil film thickness at meshing points in a planetary gear train according to the present invention;

[0026] Figure 8 This is a schematic diagram of the in-machine measurement device for the fractal features of gear surfaces in a planetary gear train as described in this invention;

[0027] Figure 9 This is a schematic diagram of the structure of the electric rotating head device for the fiber optic transmitter described in this invention.

[0028] 1-Magnetic levitation guide rail, 2-Positioning bolt, 3-Pressure washer, 4-Robotic arm base, 5-Robotic arm motion controller, 6-Robotic arm waist joint, 7-Robotic arm shoulder joint, 8-Linkage, 9-Robotic arm elbow joint, 10-Robotic arm wrist joint, 11-Multifunctional measuring head, 12-Cast iron T-shaped platform, 13-Motor base, 14-Motor, 15-Gearbox, 16-Sun gear, 17-Planetary gear, 18-User terminal microcomputer, 19-Data acquisition system, 20-Placement platform, 21-Magnetic levitation guide rail beam, 22-Guide groove, 23-Electromagnetic coil, 24-Guide coil, 25-Fiber optic transmitter, 26-Fiber optic displacement sensor, 27-Oil film thickness measuring device, 28-Fractal feature measuring device, 29-Visible light laser, 30-Visible light laser collector, 31-Electric telescopic joint, 32-Electric rotating head. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0030] See Figure 4This embodiment describes an in-machine measurement device for fractal features on the surface of gears and oil film thickness at meshing points in a planetary gear train. A magnetic levitation guide rail 1 is connected to a cast iron T-shaped platform 12 below the robotic arm. The robotic arm base 4 is slidably connected to the magnetic levitation guide rail 1. The robotic arm waist joint 6 and robotic arm shoulder joint 7 are connected via an internal flange. The robotic arm shoulder joint 7 and robotic arm elbow joint 9 are connected via a connecting rod 8. The robotic arm elbow joint 9 is connected to the robotic arm wrist joint 10. The robotic arm wrist joint 10 is connected to a multi-functional measuring head 11 of the end effector. An oil film thickness measuring device 27 and a fractal feature measuring device 28 are both arranged on the multi-functional measuring head 11. The oil film thickness measuring device 27 includes an optical fiber transmitter 25 and an optical fiber displacement sensor 26. The fractal feature measuring device 28 includes a visible light laser 29 and a visible light laser collector 30. The magnetic levitation guide rail 1 has a guide groove 22 and a recess beside it.

[0031] 1. In this example, the position is adjusted by moving the device using a magnetically levitated guide groove, and the measurement device is switched by rotating the multifunctional measuring head at the end of the robotic arm. The oil film thickness measuring device 27 includes two fiber optic transmitters 25 and one fiber optic displacement sensor 26. The fractal feature measuring device 28 includes two visible light lasers 29 and two visible light laser collectors 30. Binocular measurement ensures the accuracy of the measurement results. The visible light lasers 29 include eight light emitters. The visible light lasers can be finely adjusted in position by the motion controller 5. The oil film thickness measuring device 27 includes two fiber optic transmitters 25 and one fiber optic displacement sensor 26. The electric telescopic joint 31 on the fiber optic transmitter 25 extends the probe length to increase the detection distance. The electric rotating head 32 on the fiber optic transmitter 26 can rotate to change the emission... The transmitter has a wide field of vision. The multi-functional measuring head 11 of the end effector of the robotic arm can convert the microcomputer signal of the user terminal into a rotation angle through a rotary encoder to achieve the purpose of switching working modes. The magnetic levitation guide rail is equipped with an electromagnetic coil 24 under the groove and guide groove 22. The electromagnetic coil 24 generates an alternating magnetic field under the action of alternating current, so that the robotic arm moves along the guide groove 22. The magnetic levitation track (1) can reduce frictional resistance and vibration and improve data accuracy during the movement of the robotic arm. The cast iron T-shaped platform 12 is fixedly connected to the gearbox 15. The motor base 13 is fixedly connected to the cast iron T-shaped platform 12. The motor 14 is placed on the motor base 13. The movement of the robotic arm is controlled by the signal output of the motion controller 5 fixed on the waist joint 6 of the robotic arm. The robotic arm base 4 is connected to the cast iron T-shaped platform 12 through the cooperation of the clamping washer 3 and the positioning bolt 2. The fiber optic displacement sensor 26 receives the optical signal of the oil film thickness at multiple points between the sun gear 16 and the planet gears 17 in the planetary gear train and transmits the signal to the data acquisition system 19. The data acquisition system 19 is connected to the user terminal microcomputer 18 through the bus port.

[0032] This example demonstrates an in-machine method for measuring the fractal features of gear surfaces and the oil film thickness at the meshing point in a planetary gear train, comprising the following steps:

[0033] Step 1: Install and fix the gearbox 15 on the cast iron T-shaped platform 12, initialize the parameters of the measuring device, power on the magnetic levitation guide rail 1, and use the fuzzy adaptive control algorithm of the robotic arm motion controller 5 to regulate the movement of the robotic arm so that the entire robotic arm moves to the area to be measured. Then, make the waist joint 6, shoulder joint 7, elbow joint 9, and wrist joint 10 of the robotic arm make adaptive adjustments to reach the area to be measured as soon as possible. After exceeding the area to be measured, the position of the robotic arm is adjusted through feedback control.

[0034] Step 2: The robotic arm can rotate the multi-functional measuring head 11 according to different measurement needs. During the measurement of the gear fractal features, the end effector of the robotic arm wrist joint 10 rotates the multi-functional measuring head 11 to switch to the fractal feature measuring device 28. The fractal feature measuring device 28 is calibrated, and the visible light laser 29 starts to work and emits laser light. The robotic arm motion controller 5 controls the robotic arm to rotate smoothly 4 times at the gear to be measured, each time making the angle rotated 90 degrees. During the rotation, the visible light laser 29 illuminates the gear to be measured. The light laser collector 30 can collect the reflected light signal and transmit the signal to the user terminal microcomputer 18 through the data acquisition system 19.

[0035] Step 3: During the measurement of the oil film thickness between the sun gear and planet gears, the end effector of the robotic arm rotates the multi-functional measuring head 11 to switch to the oil film thickness measuring device 27. The robotic arm is adjusted to the position to be measured by the robotic arm motion controller 5. The fiber optic transmitter 25 emits light signals to the meshing point of the sun gear 16 and planet gear 17. The fiber optic displacement sensor 26 collects the light signals reflected back through the oil film. The position of the robotic arm is then finely adjusted by the robotic arm motion controller 5. The oil film thickness is measured at multiple points. The average value of the measurement results is taken. The light signals are transmitted to the user terminal microcomputer 18 through the data acquisition system 19.

[0036] Step 4: On the user terminal microcomputer 18, coordinate transformation is performed using the acquired optical signal. A three-dimensional mathematical model of oil film thickness is established by using the data obtained by the data acquisition system 19. The three-dimensional mathematical model of oil film thickness is then corrected by combining it with the formula. The measurement data of the fiber optic displacement sensor 26 and the measurement data of the visible light laser collector 30 are read and recorded. The images are then fused to construct a three-dimensional model of oil film thickness.

[0037] Step 5: Reset the robotic arm to its initial position by controlling the robotic arm motion controller 5.

[0038] An in-machine measurement device for the fractal features of gear surfaces and the oil film thickness at meshing points in planetary gear trains utilizes visible light and laser 3D reconstruction technology to acquire information on the fractal features of gear surfaces and the 3D oil film thickness in the meshing contact area. 3D reconstruction of the surface fractal features and oil film thickness is achieved through post-processing of the optical signals. The surface fractal feature measurement device used in this device is an integrated visible light laser product, capable of synchronous execution of light emission and collection. Signal recognition, signal post-processing, and 3D image reconstruction are all completed on the user terminal microcomputer. The movement of the robotic arm is controlled and adjusted by a robotic arm motion controller for each joint. Each joint in the robotic arm can be placed at any position in any plane. To achieve coordinate system transformation, the DH method is used to transform the coordinate system of each joint. The transformation matrix formula is as follows:

[0039]

[0040] In the formula, i is the link coordinate system of the robotic arm, and θ i Let α be the rotation angle of the robotic arm's link about the Z-axis. i Let d be the rotation angle of the link of the robotic arm about the X-axis. i This represents the distance the robotic arm's linkage moves along the Z-axis.

[0041] Given the joint variable parameters, the pose equation of the robotic arm end effector is:

[0042]

[0043] The rotational velocity and displacement of each joint are calculated using inverse kinematics. This data is then output to the control joints via a user terminal microcomputer, which adjusts the joint rotation angle and displacement for the next moment. Errors are inevitable during the robotic arm's movement. Displacement sensors installed at the end of the robotic arm transmit this data to the user control terminal. A fuzzy adaptive control algorithm calculates the error offset, and the terminal feeds back the error control value to the robotic arm, enabling it to move to the designated position more quickly and accurately.

[0044] When a gear undergoes elastic deformation, the clearance height of the contact pair can be composed of rigid body displacement, geometric clearance, tooth surface roughness, and elastic deformation. The total clearance height can be expressed as:

[0045]

[0046] In the formula, h0 is the clearance between the surfaces of the two gears, h g h is the gap between the contact pairs. g =x 2 / 2R0, r0 is s1, s2 are the oil film thicknesses formed by the surface roughness of the two gears, and E' is the equivalent elastic modulus. v is the gear's Poisson's ratio, and E is the gear's elastic modulus.

[0047] The optical signal acquired by the data acquisition system 19 is processed by median filtering. By replacing a point in the numerical sequence with the median of the neighborhood of that point, the signal is denoised, making the data closer to the true value and eliminating the influence of the difference points on the result.

[0048] The foregoing has provided a detailed description of an in-machine measurement device and method for the fractal features of gear surfaces and the thickness of oil film at meshing points in a planetary gear train. The above examples illustrate the principles and implementation methods of the invention to aid in understanding its methods and core concepts. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there may be changes in specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the invention.

Claims

1. An in-machine measuring device for the fractal features of gear surfaces and the thickness of oil film at meshing points in a planetary gear train, characterized in that: The magnetic levitation guide rail (1) below the robotic arm base (4) is connected to the cast iron T-shaped platform (12). The robotic arm base (4) and the magnetic levitation guide rail (1) are slidably connected. The robotic arm waist joint (6) and the robotic arm shoulder joint (7) are connected through an internal flange. The robotic arm shoulder joint (7) and the robotic arm elbow joint (9) are connected through a connecting rod (8). The robotic arm elbow joint (9) is connected to the robotic arm wrist joint (10). The robotic arm wrist joint (10) is connected to the end effector multi-functional measuring head. (11) Connected, the oil film thickness measuring device (27) and the fractal feature measuring device (28) are both arranged on the multi-functional measuring head (11). The oil film thickness measuring device (27) includes an optical fiber transmitter (25) and an optical fiber displacement sensor (26). The fractal feature measuring device (28) includes a visible light laser (29) and a visible light laser collector (30). The magnetic levitation rail (1) is provided with a guide groove (22). The magnetic levitation rail (1) is provided with a groove next to it. The fractal feature measurement device (28) includes two visible light lasers (29) and two visible light laser collectors (30). Binocular measurement ensures the accuracy of the measurement results. The visible light laser (29) includes eight light emitters. The visible light laser is finely adjusted in position by a motion controller (5). The oil film thickness measurement device (27) includes two fiber optic emitters (25) and a fiber optic displacement sensor (26). The electric telescopic joint (31) on the fiber optic emitter (25) extends the probe length to increase the detection distance. The electric rotating head (32) on the fiber optic emitter (25) rotates to change the wide field of view of the emitter. The multi-functional measuring head (11) of the end effector of the robotic arm converts the microcomputer signal of the user terminal into a rotation angle through a rotary encoder to achieve the purpose of switching working modes. The magnetic levitation guide rail has an electromagnetic coil (24) installed under the groove and guide groove (22). The electromagnetic coil (24) generates an alternating magnetic field under the action of alternating current, causing the robot arm base (4) to move along the guide groove (22). The magnetic levitation guide rail (1) reduces frictional resistance and vibration while improving data accuracy during the movement of the robot arm.

2. The in-machine measuring device for the fractal features of gear surfaces and the thickness of oil film at meshing points in a planetary gear train according to claim 1, characterized in that: The cast iron T-shaped platform (12) is fixedly connected to the gearbox (15), the motor base (13) is fixedly connected to the cast iron T-shaped platform (12), the motor (14) is placed on the motor base (13), and the movement of the robotic arm is adjusted by the position of the motion controller (5) fixed on the waist joint (6) of the robotic arm through the signal output by the adaptive control algorithm.

3. The in-machine measuring device for the fractal features of gear surfaces and the thickness of oil film at meshing points in a planetary gear train according to claim 1, characterized in that: The robotic arm base (4) is connected to the cast iron T-shaped platform (12) by means of a clamping washer (3) and a positioning bolt (2).

4. The in-machine measuring device for the fractal features of gear surfaces and the thickness of oil film at meshing points in a planetary gear train according to claim 1, characterized in that: The fiber optic displacement sensor (26) receives optical signals of the oil film thickness at multiple points between the sun gear (16) and planet gears (17) in the planetary gear train and transmits the signals to the data acquisition system (19). The visible light laser (29) emits laser light to illuminate the surface of the gear under test and transmits the optical signals to the data acquisition system (19) through the visible light laser collector (30). The data acquisition system (19) is connected to the user terminal microcomputer (18) through a bus port.

5. A measurement method based on the in-machine measuring device for the fractal features of gear surfaces and the oil film thickness at the meshing point in a planetary gear train as described in claim 1, characterized in that: It includes the following steps: Step 1: Install and fix the gearbox (15) on the cast iron T-shaped platform (12), initialize the parameters of the measuring device, power on the magnetic levitation guide rail (1), and use the fuzzy adaptive control algorithm of the robotic arm motion controller (5) to regulate the movement of the robotic arm so that the robotic arm moves to the area to be measured. Then, make the waist joint (6), shoulder joint (7), elbow joint (9), and wrist joint (10) of the robotic arm make adaptive adjustments to reach the area to be measured as soon as possible. After exceeding the area to be measured, adjust the position of the robotic arm through feedback control. Step 2: The robotic arm rotates the multi-functional measuring head (11) according to different measurement requirements. During the measurement of the fractal features on the gear surface, the end effector of the robotic arm wrist joint (10) rotates the multi-functional measuring head (11) to switch to the fractal feature measuring device (28). The fractal feature measuring device (28) is calibrated, and the visible light laser (29) starts to work and emits laser light. The robotic arm motion controller (5) controls the robotic arm to rotate smoothly 4 times at the gear to be measured, each time making the angle rotated 90 degrees. During the rotation, the visible light laser (29) irradiates the surface of the gear to be measured. The light laser collector (30) collects the reflected light signal and transmits the signal to the user terminal microcomputer (18) through the data acquisition system (19). Step 3: During the measurement of the oil film thickness between the sun gear and the planet gear, the end effector of the robotic arm rotates the multi-functional measuring head (11) to switch to the oil film thickness measuring device (27). The robotic arm is adjusted to the position to be measured by the robotic arm motion controller (5). The fiber optic transmitter (25) emits light signals to the meshing point of the sun gear (16) and the planet gear (17). The fiber optic displacement sensor (26) collects the light signals reflected back through the oil film. The position of the robotic arm is then finely adjusted by the robotic arm motion controller (5). The oil film thickness is measured at multiple points. The average value of the measurement results is taken. The light signals are transmitted to the user terminal microcomputer (18) through the data acquisition system (19). Step 4: On the user terminal microcomputer (18), coordinate transformation is performed using the acquired light signal. A three-dimensional mathematical model of oil film thickness is established by using the data obtained from the data acquisition system (19). The three-dimensional mathematical model of oil film thickness is then corrected by combining it with the theoretical formula. The measurement data of the fiber displacement sensor (26) is read and recorded, and the measurement data of the visible light laser collector (30) is read and recorded. The images are fused to construct a three-dimensional model of oil film thickness. Step 5: Reset the robotic arm to its initial position using the robotic arm motion controller (5).

Images