High-precision three-degree-of-freedom attitude adjustment platform for spectrometer

Abstract

The invention discloses a high-precision three-degree-of-freedom attitude adjustment platform for a spectrometer, which is based on a simplified design of a Stewart platform and comprises a movable platform, a static platform and a three-degree-of-freedom driving mechanism connected between the movable platform and the static platform. The driving mechanism is composed of three sets of servo electric cylinders, telescopic rods and servo motors and is driven by a ball screw, and posture adjustment of the platform is achieved. According to the platform, a laser interferometer is adopted as a high-precision sensor, a closed-loop feedback control system is combined, and submicron displacement measurement and attitude control are achieved. The platform can achieve translation in the Z-axis direction and rotation around the X axis and the Y axis, the rotation angle can reach + / -15 degrees, and the precision can reach 0.02 mm. According to the invention, the device ensures high precision and stability in a complex working environment, has the characteristics of stable movement, quick response, easy maintenance and the like, and is suitable for the fields of optical experiments, spectral analysis and attitude adjustment and error compensation of precise instruments.

Description

Technical Field

[0001] The invention relates to the technical field of spectrometer and precision optical instrument platform adjustment, and in particular to a high-precision three-degree-of-freedom attitude adjustment platform for a spectrometer. Background Art

[0002] Existing optical instrument adjustment platforms, especially six-degree-of-freedom platforms, can provide comprehensive posture adjustment, but their complex structure, high manufacturing cost, and high energy consumption make them unsuitable for scenes that require high precision and low cost, such as spectrometers. In addition, the multiple degrees of freedom linkage adjustment of the six-degree-of-freedom platform makes the control complex and difficult to achieve rapid response, which is not conducive to the precision optical system that requires frequent adjustment.

[0003] Traditional three-degree-of-freedom platforms are used in some applications, usually relying on manual adjustment or hydraulic / pneumatic control, but these platforms have deficiencies in adjustment speed and accuracy, especially under high loads and long-term operation, and it is difficult to maintain stable high-precision adjustment. They often cannot meet the needs of spectrometers and other optical systems for fast and high-precision adjustment.

[0004] In addition, existing sensor technology has limitations in high-precision displacement and angle measurement, and it is difficult to meet the measurement needs of sub-micron level. As a high-precision measurement device, laser interferometer has the advantages of high resolution, fast response, and good stability, and is suitable for displacement and angle measurement of precision machinery. Summary of the invention

[0005] In view of the shortcomings existing in the prior art, the purpose of the present invention is to provide a high-precision three-degree-of-freedom attitude adjustment platform for a spectrometer. Based on the combined design of a servo electric cylinder and a precision ball screw, a laser interferometer is used as a high-precision sensor, which can achieve a translation of ±30 mm in the Z-axis direction and a rotation adjustment of ±15 degrees around the X-axis and Y-axis. The platform is monitored and adjusted in real time through a closed-loop feedback control system to ensure accuracy and stability under high load and long-term use. The platform has a simplified structure, low energy consumption, and controllable costs. It is particularly suitable for optical path adjustment, detector calibration, and high-precision real-time adjustment of optical elements in a spectrometer. In order to achieve the above-mentioned purpose and other advantages according to the present invention, a high-precision three-degree-of-freedom attitude adjustment platform for a spectrometer is provided, comprising:

[0006] The platform adopts a combination design of three sets of servo electric cylinders and precision ball screws, combined with a laser interferometer as a high-precision sensor, which can achieve a translation of the dynamic platform of ±30mm in the Z-axis direction and a rotation of ±15 degrees around the X-axis and Y-axis. Through the optimized mechanical structure and control system design, the system complexity and energy consumption are reduced, ensuring high-precision posture adjustment and fast dynamic response in the optical system.

[0007] The three-degree-of-freedom platform of the present invention is particularly suitable for high-precision scenarios such as spectrometers, optical element positioning, detector calibration, and optical path adjustment. Compared with the traditional six-degree-of-freedom platform, this platform simplifies the structure and removes unnecessary degrees of freedom, which not only reduces costs but also improves the reliability and adjustment efficiency of the system. Especially under the conditions of complex loads and long-term operation, it can still maintain stable high-precision posture adjustment.

[0008] The present invention realizes precise adjustment of the dynamic platform through three sets of servo electric cylinders. The platform provides 0.02mm repeatability through precision ball screws, and combines the submicron measurement of laser interferometers to achieve higher control accuracy, which is particularly suitable for optical element calibration, optical path adjustment and error compensation in spectrometers. Compared with traditional mechanical adjustment systems, ball screws effectively eliminate gap and friction problems, ensure the speed and stability of dynamic response, and are suitable for optical systems with high requirements for real-time adjustment.

[0009] This platform uses evenly distributed multi-point hinges to connect the dynamic platform and the static platform to ensure the stability of the dynamic platform's posture adjustment under high load conditions, avoid adverse effects on the optical path accuracy of the spectrometer due to instability or vibration, and further ensure the reliability and accuracy of the system during operation.

[0010] The servo motor adopts a low inertia design and monitors and adjusts the platform posture in real time through a closed-loop feedback control system. As a high-precision sensor, the laser interferometer provides sub-micron displacement and angle measurement. Combined with a high-precision control algorithm, it can dynamically adjust the parameters of the servo motor according to actual application requirements, ensuring fast response of high-precision adjustment, and is suitable for optical equipment and spectral systems that require complex posture adjustment.

[0011] In order to improve the maintainability and flexibility of the system, the present invention adopts a modular design. The electric cylinder, servo motor and support rod are all independent and replaceable modules. Users can flexibly configure components according to the needs of actual application scenarios, which is convenient for later maintenance or function expansion. The platform is widely used in spectral analysis, laser system debugging, optical experiments and other application scenarios that require precise adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A front view of a high-precision three-degree-of-freedom posture adjustment platform for a spectrometer according to the present invention;

[0013] Figure 2 A schematic diagram of the three-dimensional structure of a high-precision three-degree-of-freedom posture adjustment platform for a spectrometer according to the present invention;

[0014] Figure 3 A schematic diagram of the connection between an electric cylinder and a servo motor of a high-precision three-degree-of-freedom posture adjustment platform for a spectrometer according to the present invention;

[0015] Figure 4 The figure is a flow chart of a closed-loop feedback control system for a high-precision three-degree-of-freedom attitude adjustment platform for a spectrometer according to the present invention. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] Reference Figure 1-4 As shown, a high-precision three-degree-of-freedom attitude adjustment platform for a spectrometer comprises:

[0018] Static platform 30;

[0019] A moving platform 20, wherein the moving platform 20 is movably connected to the static platform 30 via a driving assembly;

[0020] At least two driving components 40 are arranged between the moving platform 20 and the static platform 30, and the moving platform 20 adjusts its posture through the driving components;

[0021] The driving assembly 40 includes a ball screw 401 disposed on the static platform 30 and an electric cylinder 201 and a servo motor 301 connected to the ball screw 401;

[0022] The end of the telescopic rod 80 in the electric cylinder 201 away from the static platform 30 is connected to the static platform 30 through the hinge shaft 50. Three driving components 40 are arranged between the dynamic platform 20 and the static platform 30, and a three-body structure is formed between the three driving components 40. The servo motor 301 drives the electric cylinder 201 through the precision ball screw 401 to realize the extension and retraction of the telescopic rod 80, thereby adjusting the posture of the dynamic platform 20.

[0023] like Figure 2 As shown, a telescopic rod 80 is installed in the electric cylinder 201, and one end of the telescopic rod 80 away from the static platform 30 is movably connected to the hinge shaft 50. The static platform 30 and the dynamic platform 20 are connected by three hinge shafts 50, and the hinge shafts 50 are evenly distributed at the bottom of the platform to ensure the stability and accuracy of the dynamic platform 20 during the posture adjustment process. The telescopic rod 80 is a telescopic structure, and its two ends are respectively hingedly connected to the static platform 30 and the dynamic platform 20 through a moving sub-mechanism. The support rod 80 is made of high-rigidity, lightweight materials to improve the accuracy and stability of the platform.

[0024] Furthermore, the telescopic rod 80 is made of a high-rigidity, lightweight material. The standard stroke of the electric cylinder 201 is 30 mm, which can be expanded as needed to meet the needs of a wide range of posture adjustments in the optical system.

[0025] Furthermore, the repeatability of the ball screw 401 reaches 0.02 mm. The ball screw 401 combined with the sub-micron measurement accuracy of the laser interferometer can ensure the optical path alignment and error compensation in the optical system.

[0026] Furthermore, the servo motor 301 is a low-inertia servo motor, and the servo motor 301 realizes the translation of the moving platform by ±30 mm in the Z-axis direction and the rotation of ±15 degrees around the X-axis and Y-axis directions through the ball screw 401.

[0027] The closed-loop feedback control system of the high-precision three-degree-of-freedom attitude adjustment platform for the spectrometer adopts closed-loop feedback control, such as Figure 4 As shown. The control system combines the laser interferometer as a high-precision position and angle sensor to monitor and feedback the posture information of the moving platform 20 in real time, automatically adjust the driving parameters of the servo motor 301, and achieve high-precision posture adjustment and path planning. The laser interferometer has sub-micron measurement accuracy and can meet the optical system's demand for high-precision measurement.

[0028] The workflow of the system is as follows:

[0029] 1. Initial posture setting: The user or system sets the target posture of the moving platform 20 according to the application requirements, including the Z-axis translation ΔZ, and the rotation angles θ_X and θ_Y around the X-axis and Y-axis. The target posture parameters are input through the human-machine interface and sent to the servo motor control system;

[0030] 2. Real-time monitoring by laser interferometer: The laser interferometer is installed between the moving platform 20 and the static platform 30 to monitor the position, angle, displacement and other posture information of the moving platform 20 in real time. The laser interferometer feeds back the actual posture data of the current platform to the controller, providing sub-micron measurement accuracy;

[0031] 3. Error calculation: The controller receives the actual posture data fed back by the laser interferometer, compares it with the set target posture parameters, and calculates the error between the actual posture and the target posture, including the translation error ΔZ_error and the rotation errors Δθ_X and Δθ_Y. ;

[0032] 4. Servo motor parameter adjustment: The controller generates adjustment instructions using the PID control algorithm based on the error calculation results to determine the adjustment amount of the servo motor 301, that is, the telescopic distance ΔL_i and telescopic speed V_i of the electric cylinder 201. The adjustment instructions are sent to each servo motor 301 through the control bus;

[0033] 5. The electric cylinder performs adjustment: The servo motor 301 receives the control command and drives the electric cylinder 201 to extend and retract through the precision ball screw 401 to adjust the length of the support rod 80. As a result, the moving platform 20 is displaced (translated along the Z axis) and rotated (rotated around the X axis and Y axis). Specifically, the relationship between the extension amount ΔL_i of the electric cylinder 201 and the posture adjustment amount of the moving platform 20 is determined by the following kinematic equation:

[0034] For Z-axis translation ΔZ:

[0035] Each electric cylinder 201 is synchronously extended or shortened by the same distance ΔL_Z, so that the movable platform 20 moves ΔZ in the Z-axis direction, and ΔL_Z=ΔZ×sin(β), where β is the angle between the support rod 80 and the Z-axis.

[0036] For the rotation θ_X around the X axis:

[0037] The electric cylinders 201 on the left and right sides of the moving platform 20 generate a length difference ΔL_X, which satisfies ΔL_X=d×sin(θ_X), where d is the horizontal distance between the left and right hinge points on the moving platform 20.

[0038] For the rotation θ_Y around the Y axis:

[0039] The electric cylinders 201 on the front and rear sides of the moving platform 20 generate a length difference ΔL_Y, which satisfies ΔL_Y=w×sin(θ_Y), where w is the horizontal distance between the front and rear hinge points on the moving platform 20.

[0040] 6. Feedback and recirculation: The adjusted posture of the moving platform 20 is again monitored in real time by the laser interferometer, and the monitoring data is fed back to the controller. The controller recalculates the error, and if the error exceeds the allowable range, steps 3 to 5 are repeated until the error is within the allowable range.

[0041] 7. Stable posture: When the actual posture data fed back by the laser interferometer is consistent with the target posture and the error is within the allowable range, the controller stops issuing new adjustment instructions. The system posture is stable and maintains the currently set posture parameters.

[0042] For example, in the application scenario of a spectrometer, the movable platform 20 needs to be moved 2 mm in the Z-axis direction, rotated 1 degree around the X-axis, and rotated 0.5 degree around the Y-axis. Based on the above requirements, the controller calculates the distance ΔL_i that each electric cylinder 201 needs to extend and retract, and controls the servo motor 301 to drive the electric cylinder 201 to extend and retract.

[0043] The specific calculation process is as follows:

[0044] Calculate the electric cylinder extension ΔL_Z required for Z-axis translation: ΔL_Z = ΔZ × sin(β)

[0045] Assuming β is 45 degrees, then ΔL_Z = 2mm×sin(45°)≈1.414mm

[0046] Each electric cylinder 201 extends synchronously by 1.414 mm.

[0047] Calculate the electric cylinder length difference ΔL_X required for rotation around the X axis:

[0048] ΔL-X=d×sin(θ_X)

[0049] Assuming d is 100mm and θ_X is 1 degree, then ΔL_X=100mm×sin(1°)≈1.745mm. The electric cylinder on the left side of the moving platform is shortened by 0.872mm, and the electric cylinder on the right side is extended by 0.872mm.

[0050] Calculate the electric cylinder length difference ΔL_Y required for rotation around the Y axis:

[0051] ΔL-Y=w×sin(θ_Y)

[0052] Assuming w is 100mm and θ_Y is 0.5 degrees, then ΔL_Y = 100mm × sin(0.5°) ≈ 0.873mm

[0053] The electric cylinder on the front side of the moving platform is shortened by 0.436mm, and the electric cylinder on the rear side is extended by 0.436mm.

[0054] By superimposing the above adjustment amounts, the controller accurately calculates the total extension and contraction amount ΔL_i of each electric cylinder 201 , controls the servo motor 301 to perform corresponding actions, and realizes the target posture of the moving platform 20 .

[0055] The driving mechanism of the platform adopts a modular design, and the electric cylinder 201, servo motor 301 and support rod 80 can be disassembled and replaced independently. Users can select components of appropriate specifications according to the load and precision requirements of different optical devices to improve the adaptability and maintainability of the system.

[0056] Both the static platform 30 and the dynamic platform 20 are made of high-strength and lightweight materials, such as aluminum alloy or carbon fiber composite materials, with high rigidity and low energy consumption. The choice of materials ensures that the platform maintains structural stability under high load conditions and adapts to the long-term complex working environment of spectrometers and optical instruments.

[0057] The servo motor 301 drives the electric cylinder 201 through the precision ball screw 401. The ball screw 401 adopts the grinding-grade manufacturing process and has extremely low friction loss and high-precision positioning performance. The low-friction design reduces mechanical wear, increases the service life of the platform, and ensures that the platform maintains high precision and stability during long-term work.

[0058] In practical applications, the three-degree-of-freedom platform of the present invention can be widely used in fields that require high-precision posture adjustment, such as spectrometers, laser systems, and optical experimental equipment. Its design is suitable for adjustment scenarios that require fast dynamic response and meets the requirements of low cost and easy maintenance. Through modular adjustment, users can flexibly configure the platform to adapt to different optical application requirements.

[0059] In summary, the high-precision three-degree-of-freedom platform provided by the present invention realizes the translation of the moving platform 20 in the Z-axis direction and the rotation adjustment around the X-axis and Y-axis through a precise mechanical structure and a closed-loop feedback control system. The platform has the advantages of high precision, fast response, simple structure, and easy maintenance, and is particularly suitable for high-precision scenarios such as optical element positioning, detector calibration, and optical path adjustment in spectrometers and optical instruments.

[0060] The number of devices and processing scales described here are used to simplify the description of the present invention, and the application, modification and variation of the present invention will be obvious to those skilled in the art.

[0061] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A high-precision three-degree-of-freedom attitude adjustment platform for a spectrometer, characterized in that: include: static platform (30); A moving platform (20), wherein the moving platform (20) is movably connected to the static platform (30) via a driving assembly; At least two driving components (40) are arranged between the moving platform (20) and the static platform (30), and the moving platform (20) adjusts its posture through the driving components; The driving assembly (40) comprises a ball screw (401) disposed on the static platform (30), and an electric cylinder (201) and a servo motor (301) connected to the ball screw (401); One end of the telescopic rod (80) in the electric cylinder (201) away from the static platform (30) is connected to the static platform (30) via a hinge shaft (50).

2. A high-precision three-degree-of-freedom attitude adjustment platform for a spectrometer as claimed in claim 1, characterized in that: Three driving components (40) are arranged between the moving platform (20) and the stationary platform (30), and a three-body structure is formed between the three driving components (40).

3. A high-precision three-degree-of-freedom attitude adjustment platform for a spectrometer as claimed in claim 1, characterized in that: A telescopic rod (80) is installed in the electric cylinder (201), and one end of the telescopic rod (80) away from the static platform (30) is movably connected to the hinge shaft (50).

4. A high-precision three-degree-of-freedom attitude adjustment platform for a spectrometer as claimed in claim 3, characterized in that: The telescopic rod (80) is made of a high-rigidity, lightweight material.

5. The high-precision three-degree-of-freedom attitude adjustment platform for a spectrometer according to claim 1, characterized in that: The repeated positioning accuracy of the ball screw (401) reaches 0.02 mm.

6. A high-precision three-degree-of-freedom attitude adjustment platform for a spectrometer as claimed in claim 1, characterized in that: The servo motor (301) is a low-inertia servo motor, and the servo motor (301) realizes the translation of the moving platform by ±30 mm in the Z-axis direction and the rotation of ±15 degrees around the X-axis and Y-axis directions through the ball screw (401).

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