Displacement sensor based on space-time transformation compensation

Abstract

The utility model relates to a space-time transformation compensation-based displacement sensor, which comprises a laser, a right-angle mirror group, a grating pair, a photoelectric receiver and a micro adjuster, and is characterized in that the laser is used for emitting a laser beam, the laser beam is sent to the right-angle mirror group and the grating pair, and the grating pair comprises an indicating grating and a scale grating; the indicating grating and the right-angle mirror group are installed on a measured object, the scale grating is installed on the micro-motion regulator, the micro-motion regulator is used for controlling the motion of the scale grating and the relative motion of the indicating grating and the scale grating to generate moire fringes, and the photoelectric receiver is used for receiving optical signals of the moire fringes generated by the grating pair. According to the displacement measurement sensor, the movement of the scale grating is adjusted by arranging the micro adjuster, the relative displacement between the grating pairs is dynamically and periodically adjusted, and incomplete moire fringes are compensated into complete moire fringes which can be identified by the photoelectric receiver, so that the measurement precision of the displacement measurement sensor is improved.

Description

Technical Field

[0001] This utility model relates to the field of grating sensor technology, specifically to a displacement sensor based on spatiotemporal transformation compensation. Background Technology

[0002] The novel principle of displacement measurement based on optical triangulation amplification combines triangular wave optics with a high-precision PSD (Position Sensitive Device) to achieve this. Through optical triangulation amplification, a small horizontal displacement t is magnified to T on the photodetector (PSD), significantly improving the accuracy of length measurement. Optical sensors have thus become widely used tools in the field of measurement technology. However, the accuracy of these sensors is closely related to the accuracy of the PSD, and further improvements in PSD accuracy remain challenging.

[0003] Moiré fringes are characterized by their extreme sensitivity to the displacement of gratings. When the grating moves relative to the grating, the moiré fringes also move accordingly. This phenomenon is widely used in precision measurement techniques, such as grating ruler displacement sensors. By calculating the changes in the moiré fringes, the displacement and velocity of an object can be accurately measured.

[0004] Since the grating measurement principle uses the counting of moiré fringes, there is a large error in counting fewer than one moiré fringe. Summary of the Invention

[0005] The purpose of this invention is to solve the technical problem of difficulty in signal resolution of moiré fringes caused by changes in light source intensity, leading to measurement errors. It provides a displacement sensor based on spatiotemporal transformation compensation. By setting a micro-adjustment to regulate the movement of the scale grating, the relative displacement between the grating pairs is dynamically and periodically adjusted, compensating for incomplete moiré fringes to form complete moiré fringes that can be recognized by a photoelectric receiver, thereby improving the measurement accuracy of the displacement sensor. The main concept is as follows:

[0006] A displacement sensor based on spatiotemporal transformation compensation is characterized by comprising a laser, a right-angle mirror group, a grating pair, a photodetector, and a micro-adjustment. The laser is used to emit a laser beam, which is sent to the right-angle mirror group and the grating pair. The grating pair includes an indicator grating and a scale grating. The indicator grating and the right-angle mirror group are mounted on the object being measured. The scale grating is mounted on the micro-adjustment, which is used to control the movement of the scale grating. The relative movement of the indicator grating and the scale grating generates moiré fringes. The photodetector is used to receive the optical signal of the moiré fringes generated by the grating pair.

[0007] This scheme places a micro-adjustment on the scale grating, enabling the scale grating to move and compensate for incomplete moiré fringes that are difficult for the photoelectric receiver to measure. The scale grating is dynamically and periodically moved forward or backward by the micro-adjustment, readjusting the relative displacement between the grating pairs, removing or adding incomplete moiré fringes. The incomplete moiré fringes are compensated into complete moiré fringes that can be recognized by the photoelectric receiver, allowing the incomplete parts of the moiré fringe count to be precisely measured by the micro-adjustment, thereby further improving the measurement accuracy of the displacement measurement sensor.

[0008] Preferably, the photoelectric receiver and the micro-adjuster are connected via a processor. The photoelectric receiver processes the light signal of the moiré fringes into an electrical signal and sends it to the processor. The processor counts the moiré fringes to calculate the displacement.

[0009] Preferably, the processor includes a signal processing circuit and a controller. The signal processing circuit is used to receive the moiré fringe optical signal and identify complete and incomplete moiré fringes. The signal processing circuit measures the value of the complete moiré fringe. The controller is used to control the micro-adjustment to drive the scale grating to perform periodic reciprocating motion, thereby realizing displacement compensation of the incomplete moiré fringes.

[0010] Preferably, the displacement value of the micro-adjustment is y, the movement time of the micro-adjustment is t, and the velocity function of the micro-adjustment driving the scale grating is f(t), where y = f(t).

[0011] Preferably, the micro-adjustment is a piezoelectric actuator.

[0012] Preferably, the laser, scale grating, micro-adjustment, and photodetector are packaged as a measurement probe, which is connected to a power supply assembly to power the laser, micro-adjustment, and photodetector. Several measurement probes are distributed around the outside of the right-angle mirror assembly, and these probes alternately and continuously measure the displacement of the object being measured.

[0013] Preferably, the measuring probe is further provided with a light intensity compensation component, which includes a beam splitter and a photoelectric compensation receiver. The beam splitter receives the laser beam emitted by the laser and splits the incident laser beam into a first laser beam and a second laser beam in proportion. The photoelectric compensation receiver is used to receive and measure the light intensity of the second laser beam.

[0014] Preferably, the photodetector is used to receive and measure the light intensity of the first laser beam, and the light intensity change rate of the second laser beam measured by the photodetector is compensated to the photodetector according to the ratio of the beam splitter.

[0015] The beneficial effects of this utility model are as follows:

[0016] By adjusting the movement of the scale grating using a micro-adjuster, the relative displacement between the grating pairs is dynamically and periodically adjusted, compensating incomplete moiré fringes into complete moiré fringes that can be recognized by the photoelectric receiver, thereby improving the measurement accuracy of the displacement measurement sensor.

[0017] Large-range displacement testing can be achieved by combining several short gratings, without the need for large-range gratings, which reduces the manufacturing cost of gratings and improves measurement accuracy. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this utility model.

[0019] Figure 2 This is a structural schematic diagram of Embodiment 3 of the present invention.

[0020] Figure 3 This is a diagram illustrating the compensation effect of Embodiment 3 of this utility model.

[0021] The attached diagram includes the following reference numerals: 1. Object under test; 2. Laser; 3. Right-angle lens group; 4. Indicator grating; 5. Scale grating; 6. Micro-adjustment; 7. Photoelectric receiver; 8. Beam splitter; 9. Photoelectric compensation receiver. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0023] It should be noted that all actions involving the acquisition of signals, information, or data in this application are carried out in compliance with the relevant data protection laws and policies of the country where the application is located, and with the authorization granted by the owner of the relevant device.

[0024] In this disclosure, unless otherwise stated, directional terms such as "inner" and "outer" are defined based on the contours of the corresponding components. Terms such as "first" and "second" used in this disclosure are for distinguishing one element from another and do not imply sequence or importance.

[0025] Example 1

[0026] like Figures 1-2As shown, an optoelectronic measuring device for displacement compensation in this embodiment includes a laser 2, a right-angle mirror group 3, a grating pair, a photodetector 7, and a micro-adjustment 6. The laser 2 is used to emit a laser beam, which is sent to the right-angle mirror group 3 and the grating pair. The grating pair includes an indicator grating 4 and a scale grating 5. The indicator grating 4 and the right-angle mirror group 3 are mounted on the object being measured 1. The scale grating 5 is mounted on the micro-adjustment 6, which is used to control the movement of the scale grating 5. The relative movement of the indicator grating 4 and the scale grating 5 generates moiré fringes. The photodetector 7 is used to receive the light signal of the moiré fringes generated by the grating pair.

[0027] The photoelectric receiver 7 and the micro-adjuster 6 are connected through a processor. The photoelectric receiver 7 is used to send the light signal of the moiré fringes to the processor, and the processor is used to calculate the displacement by counting the moiré fringes.

[0028] The processor includes a signal processing circuit and a controller. The signal processing circuit is used to receive the moiré fringe light signal and identify complete and incomplete moiré fringes. The signal processing circuit measures the value of the complete moiré fringe. The controller is used to control the micro-adjustment 6 to drive the scale grating 5 to perform periodic reciprocating motion to achieve displacement compensation of incomplete moiré fringes.

[0029] In this embodiment, the micro-adjustment 6 is disposed on the scale grating 5, enabling the scale grating 5 to move and compensate for incomplete moiré fringes that are difficult for the photoelectric receiver 7 to measure. The scale grating 5 is dynamically and periodically moved forward or backward by the micro-adjustment 6, readjusting the relative displacement between the grating pairs, removing or adding incomplete moiré fringes, and compensating for incomplete moiré fringes to complete moiré fringes that can be recognized by the photoelectric receiver 7. This allows the incomplete part of the moiré fringe count to be precisely measured by the micro-adjustment 6, thereby further improving the measurement accuracy of the displacement measurement sensor.

[0030] Example 2

[0031] like Figures 1-2 As shown, the displacement value of the micro-adjustment 6 in this embodiment is y, the movement time of the micro-adjustment 6 is t, and the velocity function of the micro-adjustment 6 driving the scale grating 5 is f(t), y = f(t).

[0032] The displacement value of the measured object 1 is D. The micro-adjustment 6 can move any one of the gratings of the grating pair to achieve displacement compensation. When the micro-adjustment 6 moves in the direction of increasing moiré fringes, the direction coefficient g = -1. When the micro-adjustment 6 moves in the direction of decreasing moiré fringes, the direction coefficient g = 1. D = d + g × y.

[0033] The micro-adjustment 6 is a piezoelectric actuator that drives the indicator grating 4 or the scale grating 5 to move. The range of motion of the micro-adjustment 6 is one grating pitch. Large-range gratings are not required; only a combination of several short gratings is needed to achieve large-range displacement testing, reducing grating manufacturing costs and improving measurement accuracy.

[0034] Example 3

[0035] like Figures 1-3 As shown, this embodiment also includes a laser 2, a scale grating 5, a micro-adjustment 6, and a photodetector packaged as a measurement probe. The measurement probe is connected to a power supply assembly, which supplies power to the laser 2, the micro-adjustment 6, and the photodetector 7. Several measurement probes are distributed outside the right-angle mirror group 3, and these probes alternately and continuously measure the displacement of the object 1 being measured.

[0036] The measuring probe is also equipped with a light intensity compensation component, which includes a beam splitter 8 and a photoelectric compensation receiver 9. The beam splitter 8 receives the laser beam emitted by the laser 2 and splits the incident laser beam into a first laser beam and a second laser beam according to a certain ratio. The photoelectric compensation receiver 9 is used to receive and measure the light intensity of the second laser beam.

[0037] The right-angle mirror group 3 includes multiple right-angle mirrors, which are composed of mutually perpendicular reflective mirrors. The right-angle mirrors cause the laser beam to be reflected twice between the two reflective mirrors, amplifying the displacement of the laser beam by a factor of two. Figure 1 As shown, the right-angle mirror magnifies the distance of the laser beam displacement by two times, resulting in higher measurement accuracy. Furthermore, by setting multiple right-angle mirrors to form a right-angle mirror group 3, the measurement range is increased.

[0038] The photoelectric receiver 7 is used to receive and measure the light intensity of the first laser beam. The light intensity change rate of the second laser beam measured by the photoelectric compensation receiver 9 is compensated to the photoelectric receiver according to the ratio of the beam splitter 8.

[0039] A beam splitter 8 is installed in the path between laser 2 and right-angle mirror group 3. The laser beam emitted by laser 2 is divided proportionally by beam splitter 8 into a first laser beam received by photoelectric receiver 7 and a second laser beam received by photoelectric compensation receiver 9. The intensity measured by the two is compared.

[0040] The intensity of the first laser beam measured by photodetector 7 is L1, and the intensity of the second laser beam measured by photodetector compensation receiver 9 is L2. L2 measured by photodetector compensation receiver 9 is used as a constant light intensity reference. The rate of change of L2 is compensated into L1 measured by photodetector 7 according to the transmission and reflection ratio of beam splitter 8. The constant light intensity measured by photodetector compensation receiver 9 compensates for the difference in light intensity L1 measured by photodetector 7, so that the error of the light intensity of the first laser beam of photodetector 7 is corrected, and an easily distinguishable moiré fringe signal is obtained.

[0041] The above descriptions are merely embodiments of this utility model, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of this utility model, and these should also be considered within the scope of protection of this utility model. These modifications will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A displacement sensor based on spatiotemporal transformation compensation, characterized in that, It includes a laser, a right-angle mirror assembly, a grating pair, a photodetector, and a micro-adjustment. The laser is used to emit a laser beam, which is sent to the right-angle mirror assembly and the grating pair. The grating pair includes an indicator grating and a scale grating. The indicator grating and the right-angle mirror assembly are mounted on the object being measured. The scale grating is mounted on the micro-adjustment, which is used to control the movement of the scale grating. The relative movement of the indicator grating and the scale grating generates moiré fringes. The photodetector is used to receive the light signal of the moiré fringes generated by the grating pair.

2. A displacement sensor based on spatiotemporal transformation compensation according to claim 1, characterized in that: The photoelectric receiver and the micro-adjuster are connected by a processor. The photoelectric receiver is used to process the light signal of the moiré fringes into an electrical signal and send it to the processor. The processor is used to count the moiré fringes to realize displacement calculation.

3. A displacement sensor based on spatiotemporal transformation compensation according to claim 2, characterized in that: The processor includes a signal processing circuit and a controller. The signal processing circuit is used to receive the moiré fringe optical signal and identify complete and incomplete moiré fringes. The signal processing circuit measures the displacement value of the complete moiré fringe. The controller is used to control the micro-adjustment to drive the scale grating to perform periodic reciprocating motion, thereby realizing displacement compensation of incomplete moiré fringes.

4. A displacement sensor based on spatiotemporal transformation compensation according to claim 3, characterized in that: The displacement value of the micro-adjustment is y, the movement time of the micro-adjustment is t, and the velocity function of the micro-adjustment driving the scale grating is f(t), y = f(t).

5. A displacement sensor based on spatiotemporal transformation compensation according to claim 1, characterized in that: The micro-adjustment is a piezoelectric actuator.

6. A displacement sensor based on spatiotemporal transformation compensation according to claim 1, characterized in that: The laser, scale grating, micro-adjustment, and photodetector are packaged as a measurement probe. The measurement probe is connected to a power supply assembly, which supplies power to the laser, micro-adjustment, and photodetector. Several measurement probes are distributed outside the right-angle mirror group, and these probes alternately and continuously measure the displacement of the object being measured.

7. A displacement sensor based on spatiotemporal transformation compensation according to claim 6, characterized in that: The measuring probe is also equipped with a light intensity compensation component, which includes a beam splitter and a photoelectric compensation receiver. The beam splitter receives the laser beam emitted by the laser and splits the incident laser beam into a first laser beam and a second laser beam in proportion. The photoelectric compensation receiver is used to receive and measure the light intensity of the second laser beam.

8. A displacement sensor based on spatiotemporal transformation compensation according to claim 7, characterized in that: The photoelectric receiver is used to receive and measure the light intensity of the first laser beam, and the light intensity change rate of the second laser beam measured by the photoelectric compensation receiver is compensated to the photoelectric receiver according to the ratio of the beam splitter.

Images