Amplitude optimization method, measuring device and machining method for diffuser blade machining

Abstract

The invention provides an amplitude optimization method, a measuring device and a machining method for diffuser blade machining, in the blade machining process, ultrasonic amplitude of a cutter is measured in real time, and data of radial amplitude of the cutter is collected; by analyzing tool ultrasonic amplitude online measurement data in first blade machining, ultrasonic amplitude parameters in second blade machining are guided to be optimized, and by parity of reasoning, ultrasonic amplitude parameters in next blade machining are guided to be optimized according to tool ultrasonic amplitude online measurement data in previous blade machining. By means of the method, multi-stage optimization of the amplitude in ultrasonic auxiliary machining of the blades is achieved, and the blade machining quality problem caused by ultrasonic amplitude fluctuation is avoided. The used measuring device is simple in structure, the mechanical arm is used for controlling the laser emitting direction of the laser displacement sensor to be perpendicular to the axis direction of the tool all the time, real-time and accurate measurement of the amplitude of the tool is achieved, and the effect of multistage optimization of the amplitude is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical processing, and more particularly to a multi-level amplitude optimization method for processing a diffuser blade, a laser measuring device, and a processing method for the diffuser blade. Background Art

[0002] Ultrasonic-assisted machining is characterized by concentrated energy, instantaneous action, intermittent machining, and rapid cutting. The periodic contact and separation between the tool and the workpiece can effectively avoid the phenomenon of tool deflection. At the same time, the pulsed high-frequency machining method has significant advantages for machining parts with complex shapes, deep cavities, micro-machining, and ultra-precision parts. Ultrasonic-assisted machining technology can significantly improve machining efficiency, surface finish, reduce machining surface stress, reduce tool wear, and greatly extend tool life for difficult-to-machine metal materials such as high-temperature alloys and titanium alloys, and non-metallic hard and brittle materials such as ceramics and silicon carbide. In the ultrasonic-assisted machining process, the amplitude of the ultrasound is a key process parameter. Stable ultrasonic amplitude can effectively reduce the roughness of the machined surface and improve the uniformity of the machined surface quality. Therefore, it is necessary to measure the amplitude of the tool and optimize the amplitude during tool machining to ensure machining quality.

[0003] For example: ① The invention patent with application publication number CN113203467A discloses a device and method for measuring the load amplitude of ultrasonic-assisted machining. The method uses a laser displacement sensor to measure the ultrasonic amplitude under no-load conditions, and measures the depth of the pit left by the tool on the workpiece surface during ultrasonic-assisted machining and uses it as the amplitude of ultrasonic-assisted machining. This design is mostly used for flat workpieces and has certain limitations for curved workpieces. ② The invention patent with authorization announcement number CN114888637A discloses a device and method for measuring the amplitude of an ultrasonic tool under load. This method measures the amplitude by installing a Hall sensor around the amplitude rod. This method measures the change in voltage signal during machining and obtains the amplitude under load based on the corresponding relationship between the no-load amplitude and the voltage signal. ③ The invention patent with application publication number CN114290423A discloses a method for amplitude measurement and tool setting. This solution is because after changing the tool, if the tool material changes, the impedance will also change, so the generated frequency will be different, which will also cause the amplitude to change. Therefore, before processing, the frequency is measured first, and then adjusted after obtaining the frequency. After adjusting it to a frequency that can generate the required amplitude, processing can be carried out. ④ The invention patent with application publication number CN113909577A discloses an ultrasonic-assisted processing system and its control method. Many amplitude values ​​under different currents are pre-stored in the CNC system in advance. Before starting processing, the amplitude is measured. If the measured amplitude value is different from the required value, the current is adjusted again until the amplitude value is adjusted to the required value before processing begins. ⑤ The invention patent with application publication number CN109029690A discloses a multi-purpose ultrasonic working state amplitude measurement method and device based on the principle of electromagnetic induction. This method obtains the numerical value of the ultrasonic amplitude by measuring the changes in the electrical signal generated by the indenter in the magnetic field. However, the method and device are too complicated and easily cause errors in the amplitude measurement, resulting in inaccurate amplitude measurements. At the same time, this method requires manual measurement and further processing of the measured electrical signal. ⑥ The invention patent with application publication number CN103557931A discloses an ultrasonic amplitude measurement device and method based on constant force control. The ultrasonic amplitude during the processing process is measured by recording the coordinates of the Z axis of the precision micro three-dimensional motion platform. This device and measurement method are also too complicated.

[0004] When an ultrasonic tool is processing, the amplitude of the tool will change as the cutting speed, cutting depth, etc. change. As can be seen from the above patents, the current measurement of the amplitude in ultrasonic-assisted processing is mostly the measurement of the ultrasonic amplitude under no-load or non-actual processing conditions. The measurement results cannot represent the ultrasonic amplitude in actual processing, so it is impossible to accurately improve the amplitude and enhance the processing quality of the workpiece.

[0005] The invention patent application, publication number CN112338633 A, discloses a novel ultrasonic real-time online amplitude measurement device, proposing real-time measurement of the tool's amplitude during workpiece machining. This proposal only proposes real-time measurement of the tool's amplitude but does not address specific application. During ultrasonic tool machining, the amplitude fluctuates with changes in cutting speed, cutting depth, and other factors. This is particularly true for diffusers with multiple blades, which are machined individually. Minimizing the impact of amplitude fluctuations on machining quality is key to improving diffuser blade machining quality. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to address the problem that amplitude fluctuation during ultrasonic tool processing affects the processing quality. By combining a real-time measurement method of tool amplitude, a method for optimizing the amplitude of diffuser blade processing is provided, and a laser measurement device and a processing method for diffuser blades are further provided.

[0007] A multi-level amplitude optimization method for diffuser blade processing. During the blade processing process, the ultrasonic amplitude of the tool is measured in real time and the data of the tool radial amplitude is collected. By analyzing the online ultrasonic amplitude measurement data in the first blade processing, the ultrasonic amplitude parameters in the second blade processing are optimized. Similarly, based on the online ultrasonic amplitude measurement data of the tool in the previous blade processing, the ultrasonic amplitude parameters in the next blade processing are optimized until the processing of all diffuser blades is completed, realizing multi-level amplitude optimization in blade ultrasonic-assisted processing.

[0008] It should be noted that the diffuser is a whole. During processing, it is not individual blades that are clamped on the machine tool, but the entire diffuser that is mounted on the machine tool. The entire diffuser only needs to be clamped and positioned once to complete processing.

[0009] The present invention combines a real-time tool amplitude measurement method to obtain the real-time ultrasonic amplitude parameters of the first blade. This guides the optimization of the ultrasonic amplitude parameters of the second blade, and so on. The ultrasonic amplitude parameters of each blade are gradually optimized, reducing the impact of ultrasonic amplitude fluctuations on blade processing quality during machining. The present invention's multi-stage amplitude optimization method ensures stable and reliable amplitude during machining.

[0010] Furthermore, based on the online measurement data of the tool ultrasonic amplitude in the processing of the previous blade, guiding the optimization of the ultrasonic amplitude parameters in the processing of the next blade means: by observing the surface morphology of the previous blade and measuring the surface roughness of the blade, adjusting the amplitude of the second blade processing by adjusting the current of the ultrasonic generator; when the surface morphology of the first blade has defects and the roughness is greater than the design value, when processing the second blade, adjusting the current to decrease and thus reduce the amplitude; when the processing effect of the first blade is no different from that in the non-ultrasonic processing state, when processing the second blade, adjusting the current to increase and thus increase the amplitude.

[0011] Surface morphology specifically refers to obvious defects on the blade surface, such as scratches, knife marks, discontinuities, etc.

[0012] Furthermore, a laser displacement sensor is used to measure the amplitude of the tool in real time. When measuring the amplitude of the tool, the amplitude of the tool end is measured, and the laser emission direction of the laser displacement sensor is always kept perpendicular to the tool axis direction to collect data on the radial amplitude of the tool.

[0013] Furthermore, a robotic arm is used to drive the laser displacement sensor to move and rotate, so that the laser emission direction of the laser displacement sensor is continuously adjusted in real time following the change of the tool posture, ensuring that the laser emission direction is always perpendicular to the tool axis direction.

[0014] The present invention also provides a laser measuring device applied to the above-mentioned method, comprising a robotic arm, a workpiece fixing fixture fixedly connected to the robotic arm, and a laser displacement sensor installed on the workpiece fixing fixture; the laser emission direction of the laser displacement sensor is controlled by the robotic arm so that the laser emission direction remains perpendicular to the tool axis direction.

[0015] The laser displacement sensor is installed on the end effector of the robotic arm and started to collect the radial amplitude of the tool during the processing. Since the tool posture changes constantly during the processing, it is necessary to control the robotic arm to drive the laser displacement sensor so that the laser emission direction remains perpendicular to the tool axis direction.

[0016] Furthermore, the workpiece fixing fixture is L-shaped, and the L-shaped workpiece fixing fixture includes a connecting plate and a mounting plate that are perpendicular to each other, the connecting plate is connected to the robotic arm, and the laser displacement sensor is fixed on the mounting plate.

[0017] Furthermore, the robotic arm is a 4-degree-of-freedom robotic arm.

[0018] The present invention also provides a method for processing diffuser blades, wherein the diffuser blades are processed using an ultrasonic-assisted processing system. The ultrasonic-assisted processing system includes a machine tool and an ultrasonic device. The machine tool includes a workbench and a tool. The ultrasonic device includes an ultrasonic generator, an ultrasonic transducer, and a horn connected in sequence. The tool is connected to the horn, and the ultrasonic transducer, horn, and tool as a whole can move in the X-axis and Z-axis directions. The workbench can move in the Y-axis direction. The tool is suspended above the workbench, and the diffuser is mounted on the workbench. The tool processes the diffuser. The above-mentioned laser measuring device is installed on the workbench. The method specifically includes the following steps:

[0019] S1: Clamp the diffuser to be processed onto the workbench to achieve installation and fixation, and at the same time install the robotic arm on the workbench, and clamp the laser displacement sensor to the end effector of the robotic arm;

[0020] S2: Adjust the movement of the worktable on the Y axis, adjust the movement of the tool on the X and Z axes, and adjust the initial position of the tool according to the size of the workpiece diffuser; write the processing trajectory according to the shape of the blade, and adjust the position of the robot arm at the same time so that the laser emission direction of the laser displacement sensor is perpendicular to the axis direction of the tool.

[0021] S3: Start the machine tool and turn on the ultrasonic generator at the same time to achieve ultrasonic-assisted machining. The ultrasonic amplitude is controlled by adjusting the current value of the ultrasonic generator.

[0022] Step S4: Turn on the laser measurement device to perform online measurement of the ultrasonic amplitude of the tool during ultrasonic-assisted machining of the first diffuser blade. Since the tool position changes constantly during machining, the robotic arm drives the laser displacement sensor to keep the laser emission direction perpendicular to the tool axis, and measures the ultrasonic amplitude in the radial direction of the tool.

[0023] S5: After processing the first blade, the laser measuring device, the ultrasonic generator, and the machine tool are turned off in sequence, the surface morphology of the first blade is observed and the surface roughness of the blade is measured, and the amplitude of the second blade processing is adjusted by adjusting the current of the ultrasonic generator; when the surface morphology of the first blade has defects and the roughness is greater than the design value, the current is adjusted to decrease to reduce the amplitude when processing the second blade; when the processing effect of the first blade is no different from that in the non-ultrasonic processing state, the current is adjusted to increase to increase the amplitude when processing the second blade;

[0024] S6: Repeat steps S3, S4 and S5 until the diffuser is processed.

[0025] Furthermore, the sampling frequency of the laser displacement sensor is at least ten times the ultrasonic frequency.

[0026] Furthermore, the roughness of the blade is measured manually using a portable roughness meter.

[0027] The present invention has the following beneficial effects:

[0028] The amplitude optimization method, measurement device, and machining method for diffuser blade machining described in the present invention first measure the tool amplitude in real time to ensure its accuracy. The tool machining amplitude of the next blade is then adjusted based on the real-time tool amplitude measurement data for the previous blade. This process continues, gradually optimizing the amplitude of all diffuser blades. This prevents the impact of tool amplitude fluctuations on blade surface machining quality during ultrasonic tool machining. The measurement device has a simple structure and uses a robotic arm to control the position of a laser displacement sensor. This allows the sensor's laser emission direction to be continuously adjusted in real time as the tool's position changes, ensuring that the laser emission direction remains perpendicular to the tool axis. This enables real-time and accurate measurement of the tool amplitude and ensures the effectiveness of multi-stage amplitude optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 This is a flow chart of a method for processing diffuser blades according to Example 3;

[0031] Figure 2 Schematic diagram of the diffuser structure;

[0032] Figure 3 This is a schematic structural diagram of the laser measurement device of Example 2;

[0033] Figure 4 It is a structural diagram of the ultrasonic assisted machining system;

[0034] Figure 5 The ultrasonic amplitude when processing the blade No. 1 in Example 3;

[0035] Figure 6 This is the ultrasonic amplitude when processing blade No. 2 in Example 3.

[0036] The serial numbers are: 1-robotic arm, 2-workpiece fixing fixture, 3-laser displacement sensor, 4-workbench, 5-tool, 6-ultrasonic transducer, 7-amplifier, 8-diffuser. DETAILED DESCRIPTION

[0037] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.

[0038] Example 1

[0039] A multi-level amplitude optimization method for diffuser blade processing. During the blade processing process, the ultrasonic amplitude of the tool is measured in real time and the data of the tool radial amplitude is collected. By analyzing the online ultrasonic amplitude measurement data in the first blade processing, the ultrasonic amplitude parameters in the second blade processing are optimized. Similarly, based on the online ultrasonic amplitude measurement data of the tool in the previous blade processing, the ultrasonic amplitude parameters in the next blade processing are optimized until the processing of all diffuser blades is completed, realizing multi-level amplitude optimization in blade ultrasonic-assisted processing.

[0040] Guiding the optimization of ultrasonic amplitude parameters in the processing of the next blade based on the online measurement data of the tool ultrasonic amplitude in the processing of the previous blade is: by observing the surface morphology of the previous blade and measuring the surface roughness of the blade, the amplitude of the second blade processing is adjusted by adjusting the current of the ultrasonic generator; when the surface morphology of the first blade has defects and the roughness is greater than the design value, when processing the second blade, the current is adjusted to decrease, thereby reducing the amplitude; when the processing effect of the first blade is no different from that in the non-ultrasonic processing state, when processing the second blade, the current is adjusted to increase, thereby increasing the amplitude.

[0041] A laser displacement sensor is used to measure the amplitude of the tool in real time. When measuring the amplitude of the tool, the amplitude of the tool end is measured, and the laser emission direction of the laser displacement sensor is always kept perpendicular to the tool axis direction to collect the data of the tool radial amplitude.

[0042] A robotic arm is used to drive the laser displacement sensor to move and rotate, so that the laser emission direction of the laser displacement sensor is continuously adjusted in real time following the change of the tool posture, ensuring that the laser emission direction is always perpendicular to the tool axis direction.

[0043] In this embodiment, a robotic arm is used to drive the laser displacement sensor to move and rotate, so that the laser emission direction is adjusted in real time and continuously according to the change of the tool posture, thus realizing the real-time measurement of the tool amplitude. After processing the first blade, according to the surface morphology and roughness of the first blade, when processing the second blade, the tool amplitude is adjusted to increase, decrease or remain unchanged, thereby reducing the influence of the tool amplitude fluctuation on the surface processing quality of the second blade. Similarly, the amplitude of subsequent blades is adjusted one by one, and the amplitude is optimized step by step, thus realizing multi-level optimization of the amplitude in the ultrasonic assisted processing of the diffuser blades, and ensuring the stability and reliability of the amplitude during the processing. Figure 2 The figure shows the structure of the diffuser. A diffuser has more than 10 blades. Figure 2The present invention can realize online measurement of ultrasonic amplitude during processing and perform multi-level optimization of the amplitude during subsequent processing, thereby avoiding poor blade processing quality caused by unstable ultrasonic amplitude and frequency.

[0044] Example 2

[0045] like Figure 3 As shown, a laser measuring device for the amplitude multi-level optimization method of blade processing described in Example 1 includes a robotic arm 1, a workpiece fixing fixture 2 fixedly connected to the robotic arm 1, and a laser displacement sensor 3 installed on the workpiece fixing fixture 2; the laser emission direction of the laser displacement sensor 3 is controlled by the robotic arm 1 so that the laser emission direction remains perpendicular to the tool axis direction.

[0046] The workpiece fixing fixture 2 is L-shaped and includes a connecting plate and a mounting plate perpendicular to each other. The connecting plate is connected to the robot arm 1 , and the laser displacement sensor 3 is fixed to the mounting plate with bolts.

[0047] The robotic arm 1 is a 4-DOF robotic arm.

[0048] The laser measurement device described in this embodiment can be directly installed on the workbench of the ultrasonic-assisted machining system and set on one side of the diffuser. During machining, the laser displacement sensor 3 is turned on, and the robotic arm 1 controls the movement of the laser displacement sensor 3 so that the laser emission direction follows the position changes of the tool and is continuously adjusted in real time. The laser emission direction is always kept perpendicular to the tool axis direction, realizing real-time online measurement of the tool amplitude and ensuring the multi-level optimization effect of the amplitude in the machining of the diffuser blades.

[0049] Example 3

[0050] A method for processing a diffuser blade, such as Figure 1 The flowchart is shown, using an ultrasonic assisted machining system to machine a diffuser blade, the ultrasonic assisted machining system includes a machine tool and an ultrasonic device, the machine tool includes a workbench 4 and a tool 5, the ultrasonic device includes an ultrasonic generator, an ultrasonic transducer 6 and a horn 7 connected in sequence; the tool 5 is connected to the horn 7, as shown in FIG. Figure 4 As shown, the ultrasonic transducer 6, the horn 7 and the tool 5 can move in the X-axis and Z-axis directions as a whole, and the workbench 4 can move in the Y-axis direction; the tool is suspended above the workbench 4, and the diffuser 8 is installed on the workbench 4, and the tool 5 processes the diffuser 8; the laser measuring device mentioned above is installed on the workbench 4, as shown in FIG. Figure 4 The diagram shows the structure of an ultrasonic assisted machining system equipped with a laser measuring device. In this embodiment, the tool 5 is a coated carbide milling cutter with a diameter of 4-10 mm.

[0051] In the present invention, the function of the ultrasonic generator is to convert the mains electricity into a high-frequency alternating current signal that matches the ultrasonic transducer 6, driving the ultrasonic transducer 6 to work. The ultrasonic transducer 6 can convert the input electrical energy into mechanical energy. The horn 7 amplifies the small amplitude output by the radiating surface of the ultrasonic transducer 6, thereby increasing the ultrasonic amplitude. The ultrasonic vibration acts on the tool 5 through the tool handle, causing the tool 5 to generate high-frequency vibrations of tens of thousands of times per second. The ultrasonic amplitude is controlled by adjusting the current value of the ultrasonic generator. In this embodiment, the current value control range is 0-1A, and the corresponding ultrasonic amplitude range is 0-10μm.

[0052] The specific steps include:

[0053] S1: The diffuser 8 to be processed is clamped onto the workbench 4 to achieve installation and fixation. At the same time, the robot arm 1 is installed on the workbench 4, and the laser displacement sensor 3 is clamped to the end effector of the robot arm 1;

[0054] S2: Adjust the movement of the workbench 4 on the Y axis, adjust the movement of the tool 5 on the X axis and the Z axis, and adjust the initial position of the tool 5 according to the size of the workpiece diffuser 8; write the processing trajectory according to the blade shape, and adjust the position of the robot arm 1 at the same time to ensure that the laser emission direction of the laser displacement sensor 3 is perpendicular to the axis direction of the tool 5.

[0055] S3: The machine tool is started, and the tool 5 begins cutting the diffuser 8 at a rotation speed of 800 rpm and a feed rate of 200 mm / min. At the same time, the ultrasonic generator is turned on and the current value of the ultrasonic generator is adjusted to 0.6 A to achieve ultrasonic-assisted processing;

[0056] Step S4: Turn on the laser measuring device to measure the ultrasonic amplitude of the tool in the ultrasonic assisted machining of the first diffuser blade online (e.g. Figure 3 As shown in the figure, the blade numbered 1 is shown. Since the position of the tool 5 changes constantly during the machining process, the robot arm 1 drives the laser displacement sensor 3 to keep the laser emission direction perpendicular to the axis direction of the tool 5, and the ultrasonic amplitude in the radial direction of the tool 5 is measured. When machining the blade numbered 1, the ultrasonic amplitude measured is as follows: Figure 3 As shown, the ultrasound amplitude is 6.8 μm;

[0057] S5: After processing the first blade, the laser measuring device, ultrasonic generator and machine tool are turned off in turn, and the surface morphology of the first blade is observed and the surface roughness of the blade is measured. It is found that there are scratches on the first blade and the surface roughness is greater than the design value. When processing the second blade (such as Figure 3 When the blade shown in the figure changes to 2), the ultrasonic current of the ultrasonic generator is adjusted to 0.5A;

[0058] S6: Repeat steps S3, S4 and S5 until the diffuser is processed. In step S5, the current of the ultrasonic generator is adjusted to increase, decrease or remain unchanged according to the surface morphology and surface roughness of the previous blade. Figure 5 As shown, the ultrasonic amplitude of the second blade is 5 μm.

[0059] The sampling frequency of the laser displacement sensor 3 is at least ten times the ultrasonic frequency.

[0060] The roughness of the blade is measured manually using a portable roughness meter.

[0061] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of the present invention.

Claims

1. A multi-level optimization method for amplitude of diffuser blade processing, characterized in that: During the blade processing process, the ultrasonic amplitude of the tool is measured in real time, and the data of the tool radial amplitude is collected; by analyzing the online measurement data of the ultrasonic amplitude in the first blade processing, the ultrasonic amplitude parameters in the second blade processing are optimized; and so on, according to the online measurement data of the tool ultrasonic amplitude in the previous blade processing, the ultrasonic amplitude parameters in the next blade processing are optimized until the processing of all the diffuser blades is completed, realizing multi-level optimization of the amplitude in the ultrasonic-assisted processing of blades.

2. The multi-level amplitude optimization method for diffuser blade machining according to claim 1, characterized in that: Guiding the optimization of ultrasonic amplitude parameters in the processing of the next blade based on the online measurement data of the tool ultrasonic amplitude in the processing of the previous blade is: by observing the surface morphology of the previous blade and measuring the surface roughness of the blade, the amplitude of the second blade processing is adjusted by adjusting the current of the ultrasonic generator; when the surface morphology of the first blade has defects and the roughness is greater than the design value, when processing the second blade, the current is adjusted to decrease, thereby reducing the amplitude; when the processing effect of the first blade is no different from that in the non-ultrasonic processing state, when processing the second blade, the current is adjusted to increase, thereby increasing the amplitude.

3. The multi-level optimization method for blade machining amplitude according to claim 1, characterized in that: A laser displacement sensor is used to measure the amplitude of the tool in real time. When measuring the amplitude of the tool, the amplitude of the tool end is measured, and the laser emission direction of the laser displacement sensor is always kept perpendicular to the tool axis direction to collect the data of the tool radial amplitude.

4. The multi-level optimization method for blade machining amplitude according to claim 3, characterized in that: A robotic arm is used to drive the laser displacement sensor to move and rotate, so that the laser emission direction of the laser displacement sensor is continuously adjusted in real time following the change of the tool posture, ensuring that the laser emission direction is always perpendicular to the tool axis direction.

5. A laser measurement device for use in the multi-level amplitude optimization method for blade machining according to any one of claims 1 to 4, comprising a robotic arm, a workpiece fixture fixedly connected to the robotic arm, and a laser displacement sensor mounted on the workpiece fixture; the robotic arm controls the laser emission direction of the laser displacement sensor so that the laser emission direction remains perpendicular to the tool axis.

6. The laser measuring device according to claim 5, characterized in that The workpiece fixing fixture is L-shaped and includes a connecting plate and a mounting plate that are perpendicular to each other. The connecting plate is connected to the robotic arm, and the laser displacement sensor is fixed on the mounting plate.

7. The laser measuring device according to claim 6, characterized in that The robotic arm is a 4-degree-of-freedom robotic arm.

8. A method for machining diffuser blades using an ultrasonic-assisted machining system, the method comprising a machine tool and an ultrasonic device, the machine tool comprising a workbench and a tool, the ultrasonic device comprising an ultrasonic generator, an ultrasonic transducer, and a horn connected in sequence; the tool being connected to the horn, the ultrasonic transducer, horn, and tool being movable in the X- and Z-axis directions, and the workbench being movable in the Y-axis direction; the tool being suspended above the workbench, the diffuser being mounted on the workbench, and the tool machining the diffuser; the workbench being mounted with the aforementioned laser measuring device, the method comprising the following steps: S1: Clamp the diffuser to be processed onto the workbench to achieve installation and fixation, and at the same time install the robotic arm on the workbench, and clamp the laser displacement sensor to the end effector of the robotic arm; S2: Adjust the movement of the worktable on the Y axis, adjust the movement of the tool on the X and Z axes, and adjust the initial position of the tool according to the size of the workpiece diffuser; write the processing trajectory according to the shape of the blade, and adjust the position of the robot arm at the same time so that the laser emission direction of the laser displacement sensor is perpendicular to the axis direction of the tool. S3: Start the machine tool and turn on the ultrasonic generator at the same time to achieve ultrasonic-assisted machining. The ultrasonic amplitude is controlled by adjusting the current value of the ultrasonic generator. Step S4: Turn on the laser measurement device to perform online measurement of the ultrasonic amplitude of the tool during ultrasonic-assisted machining of the first diffuser blade. Since the tool position changes constantly during machining, the robotic arm drives the laser displacement sensor to keep the laser emission direction perpendicular to the tool axis, and measures the ultrasonic amplitude in the radial direction of the tool. S5: After processing the first blade, the laser measuring device, the ultrasonic generator, and the machine tool are turned off in sequence, the surface morphology of the first blade is observed and the surface roughness of the blade is measured, and the amplitude of the second blade processing is adjusted by adjusting the current of the ultrasonic generator; when the surface morphology of the first blade has defects and the roughness is greater than the design value, the current is adjusted to decrease to reduce the amplitude when processing the second blade; when the processing effect of the first blade is no different from that in the non-ultrasonic processing state, the current is adjusted to increase to increase the amplitude when processing the second blade; S6: Repeat steps S3, S4 and S5 until the diffuser is processed.

9. The method for processing a diffuser blade according to claim 8, wherein: The sampling frequency of the laser displacement sensor is at least ten times the ultrasonic frequency.

10. The method for processing a diffuser blade according to claim 8, wherein: The roughness of the blade is measured manually using a portable roughness meter.

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