Mileage sensor verification and calibration system based on laser Doppler velocity measurement

Abstract

The invention relates to the technical field of sensor verification and calibration, and discloses a laser Doppler velocimeter-based mileage sensor verification and calibration system, which comprises a support table, a laser Doppler velocimeter, a roller, a mileage sensor, a standard object, a data acquisition and processing system and a control system. Compared with the prior art, the device has the advantages that the detected mileage sensor is mounted on the fixed shaft with the same diameter as an actual wheel, the motor drives the fixed shaft to rotate and drives the mileage sensor to rotate along with the roller, and a laser beam emitted by the laser Doppler velocimeter irradiates a standard object; the mileage sensor records the number of turns of rotation of the standard object and outputs corresponding mileage signals, errors of the mileage sensor are calculated through analysis and processing of the data collecting and processing system, errors existing in the mileage sensor are calculated, and compensation is carried out by adjusting parameters of the mileage sensor or using polynomial fitting and other methods.

Description

Technical Field

[0001] The invention relates to the technical field of sensor verification and calibration, and in particular to a mileage sensor verification and calibration system based on laser Doppler speed measurement. Background Art

[0002] In the fields of modern transportation and industrial automation, mileage sensors do play a vital role. In the field of transportation, whether it is a car, train or other means of transportation, mileage sensors can accurately measure the moving distance of the vehicle and provide key data for the vehicle's navigation system. Accurate mileage information helps drivers understand the driving status and position of the vehicle and ensure the safety and accuracy of driving. The data of mileage sensors are also used for vehicle maintenance and management. By recording the mileage, maintenance and repair can be carried out in time to extend the service life of the vehicle; in the industrial production process, mileage sensors are widely used in displacement monitoring and other aspects. For example, in an automated production line, it is necessary to accurately measure the transmission distance and position of materials to ensure the smooth progress of the production process. The mileage sensor can monitor the moving distance of the material in real time and cooperate with the control system to realize automated production process control. In some high-precision industrial production fields, such as semiconductor manufacturing and precision machining, the measurement accuracy of displacement is extremely high, and the accuracy of the mileage sensor directly affects the quality and production efficiency of the product.

[0003] Due to various factors, errors may occur in the mileage sensor during use. Long-term use may also cause wear and aging of the mileage sensor, further affecting its measurement accuracy. Traditional mileage sensor calibration methods mainly use mechanical measuring devices, such as the roller method and the tape measure method. These methods have the disadvantages of low accuracy, complex operation, and great influence by environmental factors. Therefore, a mileage sensor calibration and error calibration system with high-precision, non-contact measurement of laser Doppler speed measurement is needed. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a mileage sensor verification and calibration system based on laser Doppler speed measurement.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a mileage sensor verification and calibration system based on laser Doppler speed measurement, comprising a support platform, a laser Doppler speedometer, a roller, a mileage sensor, a standard object, a data acquisition and processing system and a control system, wherein the laser Doppler speedometer is used to measure the moving speed of an object; the roller is used to carry the mileage sensor and the standard object to be verified and make them move at a stable speed; the data acquisition and processing system is used to collect the output data of the laser Doppler speedometer and the mileage sensor and analyze and process them; the control system is used to control the speed and direction of the roller and the working state of the laser Doppler speedometer and the mileage sensor; the laser Doppler speedometer is used as a The core component of the system has the advantages of high precision, high resolution and non-contact measurement when measuring the moving speed of an object, and can accurately measure the moving speed of the object corresponding to the mileage sensor. The laser Doppler velocimeter is usually composed of a laser, an optical system, a detector, and a signal processing circuit. The data acquisition and processing system is responsible for collecting the output data of the laser Doppler velocimeter and the mileage sensor, and analyzing and processing them. The data acquisition and processing system includes a data acquisition card and computer software. The data acquisition card can collect the analog signal or digital signal of the sensor in real time and transmit it to the computer for processing. The computer software can analyze the collected data, calculate the error, and generate a calibration report.

[0006] Laser source: It uses a high-stability, high-power laser that can emit a laser beam of a specific wavelength, has good stability and coherence, and can provide a high-quality laser beam;

[0007] Optical system: includes the transmitting optical system and the receiving optical system. The transmitting optical system focuses and collimates the laser beam and then irradiates it onto the object to be measured. The receiving optical system collects the laser beam reflected by the object to be measured and guides it to the detector. For example, the transmitting optical system composed of a convex lens and a reflector can focus the laser beam into a small spot to improve the measurement resolution. The receiving optical system uses a highly sensitive photodetector to effectively collect the reflected light signal.

[0008] Detector: A photoelectric detector with high sensitivity and high response speed, such as a photomultiplier tube or avalanche photodiode, is used to convert the received optical signal into an electrical signal. The output signal of the detector is amplified, filtered, and then sent to the signal processing unit for analysis;

[0009] Signal processing unit: processes the electrical signal output by the detector, extracts the Doppler frequency shift information, and calculates the speed of the object being measured. The signal processing unit can use high-speed digital signal processing devices such as digital signal processors (DSP) or field programmable gate arrays (FPGA), which can quickly and accurately process large amounts of data.

[0010] As a further description of the above technical solution:

[0011] The top of the support platform is fixedly connected to a side plate and a fixed frame, the side edge of the side plate is fixedly connected to a motor, the output end of the motor passes through the side plate and is fixedly connected to a fixed shaft, the outer side of the fixed shaft is fixedly connected to a roller, one end of the fixed shaft is fixedly connected to a mileage sensor, the standard object is connected to the outer side of the roller, the upper end of the fixed frame is fixedly connected to a laser Doppler velocimeter, and the motor adopts a high-precision drive system, which can provide a stable and accurate movement speed.

[0012] As a further description of the above technical solution:

[0013] The axis of the mileage sensor is concentric with the axis of the roller.

[0014] As a further description of the above technical solution:

[0015] The marking length of the standard object is precisely known.

[0016] As a further description of the above technical solution:

[0017] The data acquisition and processing system includes a data acquisition card and computer software, wherein the data acquisition card is used to collect analog signals or digital signals of the sensor in real time and transmit them to the computer, and the computer software is used to analyze the collected data, calculate errors and generate a calibration report;

[0018] Data acquisition card: Use a high-speed, high-precision data acquisition card that can collect the output signals of the laser Doppler speed meter and mileage sensor in real time. The sampling frequency and resolution of the data acquisition card should be selected according to the measurement requirements to ensure that the signal changes can be accurately collected;

[0019] Computer: used to process and analyze the collected data. The computer can be installed with special data analysis software to perform data filtering, spectrum analysis, error calculation and other processing to obtain accurate measurement results.

[0020] As a further description of the above technical solution:

[0021] The formula of the mileage sensor measurement error is: error=[mileage sensor measurement value-laser Doppler velocimeter measurement value×time] / laser Doppler velocimeter measurement value×time×100%.

[0022] As a further description of the above technical solution:

[0023] The surface of the standard object is provided with a plurality of groups of equidistant scale marks;

[0024] The laser Doppler velocimeter emits a laser beam to illuminate the surface of a moving standard object. The reflected light interferes with the reference light in the detector. Due to the movement of the object, the frequency of the reflected light will undergo a Doppler frequency shift, and the frequency of the interference signal will also change accordingly. By processing the interference signal, the Doppler frequency shift can be obtained, and the speed of the object can be calculated.

[0025] The present invention has the following beneficial effects:

[0026] 1. In the present invention, the mileage sensor to be tested is installed on a fixed shaft with the same diameter as the actual wheel to ensure that the mileage sensor can accurately sense the movement of the roller and the standard object, and then the motor is started to drive the fixed shaft to rotate, thereby driving the mileage sensor to rotate with the roller, and at the same time, the laser Doppler velocimeter is turned on, so that the laser beam emitted by the laser Doppler velocimeter is irradiated on the standard object. At the same time, the mileage sensor records the number of revolutions of the standard object to output a corresponding mileage signal, and then the error of the mileage sensor is calculated through analysis and processing by the data acquisition and processing system. The method has high measurement accuracy, accurately measures the moving speed of the standard object, and is non-contact measurement, which will not interfere with the movement of the standard object and will not be affected by the surface condition of the standard object.

[0027] 2. In the present invention, if it is calculated that the mileage sensor has an error, compensation is performed by adjusting the parameters of the mileage sensor or using methods such as polynomial fitting, and the calibration effect is verified again after calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The overall structure of the mileage sensor calibration system based on laser Doppler speed measurement proposed by the present invention is shown in FIG. Figure 1 ;

[0029] Figure 2 The overall structure of the mileage sensor calibration system based on laser Doppler speed measurement proposed by the present invention is shown in FIG. Figure 2 .

[0030] Legend:

[0031] 1. Support platform; 2. Side plate; 3. Motor; 4. Fixed shaft; 5. Roller; 6. Standard object; 7. Odometer sensor; 8. Fixed bracket; 9. Laser Doppler velocimeter. DETAILED DESCRIPTION

[0032] 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.

[0033] Reference Figure 1-Figure 2 The present invention provides an embodiment: a mileage sensor calibration system based on laser Doppler speed measurement, comprising a support platform 1, a laser Doppler speed meter 9, a roller 5, a mileage sensor 7, a standard object 6, a data acquisition and processing system and a control system, wherein the laser Doppler speed meter 9 is used to measure the moving speed of an object; the roller 5 is used to carry the mileage sensor 7 and the standard object 6 to be calibrated and make them move at a stable speed; the data acquisition and processing system is used to collect output data of the laser Doppler speed meter 9 and the mileage sensor 7 and perform analysis and processing; the control system is used to control the speed and direction of the roller 5 and the working state of the laser Doppler speed meter 9 and the mileage sensor 7; the laser Doppler speed meter 9 As the core component of the system, it has the advantages of high precision, high resolution and non-contact measurement when measuring the moving speed of an object, and can accurately measure the moving speed of the object corresponding to the mileage sensor 7. The laser Doppler velocimeter 9 is usually composed of a laser, an optical system, a detector, and a signal processing circuit. The data acquisition and processing system is responsible for collecting the output data of the laser Doppler velocimeter 9 and the mileage sensor 7, and analyzing and processing them. The system includes a data acquisition card and computer software. The data acquisition card can collect the analog signal or digital signal of the sensor in real time and transmit it to the computer for processing. The computer software can analyze the collected data, calculate the error, and generate a calibration report.

[0034] Laser source: It uses a high-stability, high-power laser that can emit a laser beam of a specific wavelength, has good stability and coherence, and can provide a high-quality laser beam;

[0035] Optical system: includes the transmitting optical system and the receiving optical system. The transmitting optical system focuses and collimates the laser beam and then irradiates it onto the object to be measured. The receiving optical system collects the laser beam reflected by the object to be measured and guides it to the detector. For example, the transmitting optical system composed of a convex lens and a reflector can focus the laser beam into a small spot to improve the measurement resolution. The receiving optical system uses a highly sensitive photodetector to effectively collect the reflected light signal.

[0036] Detector: A photoelectric detector with high sensitivity and high response speed, such as a photomultiplier tube or avalanche photodiode, is used to convert the received optical signal into an electrical signal. The output signal of the detector is amplified, filtered, and then sent to the signal processing unit for analysis;

[0037] Signal processing unit: processes the electrical signal output by the detector, extracts the Doppler frequency shift information, and calculates the speed of the object being measured. The signal processing unit can use high-speed digital signal processing devices such as digital signal processors (DSP) or field programmable gate arrays (FPGA), which can quickly and accurately process large amounts of data.

[0038] The top of the support platform 1 is fixedly connected with a side plate 2 and a fixing frame 8, the side edge of the side plate 2 is fixedly connected with a motor 3, the output end of the motor 3 passes through the side plate 2 and is fixedly connected with a fixing shaft 4, the outer side of the fixing shaft 4 is fixedly connected with a roller 5, one end of the fixing shaft 4 is fixedly connected with a mileage sensor 7, a standard object 6 is connected and arranged on the outer side of the roller 5, the upper end of the fixing frame 8 is fixedly connected with a laser Doppler velocimeter 9, the axis of the mileage sensor 7 is concentric with the axis of the roller 5, the marking length of the standard object 6 is precisely known, the data acquisition and processing system includes a data acquisition card and computer software, the data acquisition card is used to collect analog signals or digital signals of the sensor in real time and transmit them to the computer, the computer software is used to analyze the collected data, calculate errors and generate a calibration report, the formula for the measurement error of the mileage sensor 7 is: error = [mileage sensor 7 measurement value - laser Doppler velocimeter 9 measurement value × time] / laser Doppler velocimeter 9 measurement value × time × 100% ， The surface of the standard object 6 is provided with equidistant scale marks.

[0039] Motor 3 uses a high-precision drive system that can provide stable and accurate movement speed;

[0040] Data acquisition card: A high-speed, high-precision data acquisition card is used to collect the output signals of the laser Doppler speed meter 9 and the mileage sensor 7 in real time. The sampling frequency and resolution of the data acquisition card should be selected according to the measurement requirements to ensure that the signal changes can be accurately collected;

[0041] Computer: used to process and analyze the collected data. The computer can be installed with special data analysis software to perform data filtering, spectrum analysis, error calculation and other processing to obtain accurate measurement results.

[0042] The laser Doppler velocimeter 9 emits a laser beam to illuminate the surface of the moving standard object 6. The reflected light and the reference light interfere with each other in the detector. Due to the movement of the object, the frequency of the reflected light will undergo a Doppler frequency shift, and the frequency of the interference signal will also change accordingly. By processing the interference signal, the Doppler frequency shift can be obtained, and then the speed of the object can be calculated.

[0043] Working principle: The mileage sensor 7 to be tested is installed on the fixed shaft 4 with the same diameter as the actual wheel to ensure that the mileage sensor 7 can accurately sense the movement of the roller 5 and the standard object 6. The motor 3 is started to drive the fixed shaft 4 to rotate, so that the fixed shaft 4 drives the mileage sensor 7 to rotate with the roller 5. At the same time, the laser Doppler velocimeter 9 is turned on so that the laser beam emitted by the laser Doppler velocimeter 9 is irradiated on the standard object 6. At the same time, the mileage sensor 7 records the number of revolutions of the standard object 6 and outputs the corresponding mileage signal. Then, after analysis and processing by the data acquisition and processing system, the error of the mileage sensor 7 is calculated. It has high measurement accuracy and can accurately measure the moving speed of the standard object 6. It is a non-contact measurement and will not interfere with the movement of the standard object 6 or be affected by the surface condition of the standard object 6.

[0044] Principle of laser Doppler speed measurement: When the laser beam is irradiated onto the surface of the standard object 6, the frequency of the reflected light will change due to the Doppler effect, and the reflected light interferes with the reference light in the detector. The frequency of the interference signal generated is proportional to the Doppler frequency shift of the reflected light. By measuring the frequency of the interference signal, the movement speed of the object under test can be calculated; the laser beam emitted by the laser Doppler speed meter 9 is focused by the optical system and irradiated onto the surface of the object under test, and the reflected light is collected by the receiving optical system and guided to the detector. The detector converts the optical signal into an electrical signal, which is sent to the signal processing unit for analysis after amplification, filtering and other processing. The signal processing unit calculates the movement speed of the object under test by measuring the frequency of the interference signal.

[0045] Working principle of mileage sensor 7: Mileage sensor 7 can be divided into mechanical mileage sensor, electronic mileage sensor and optical mileage sensor according to different measurement principles. Mechanical mileage sensor usually calculates mileage by measuring the number of rotations of the wheel; electronic mileage sensor uses principles such as Hall effect and magnetoresistance effect to measure the rotation speed of the wheel; optical mileage sensor calculates mileage by measuring the displacement of the object; different types of mileage sensors 7 have different working principles, but their output signals are all related to the moving distance or speed of the object. In this system, mileage sensor 7 is installed on the fixed shaft 4 and moves with the object to be measured. The output signal is collected by the data acquisition card and sent to the computer for processing and analysis.

[0046] Error calibration is to determine the error characteristics of the mileage sensor 7 based on the test results. If the error is linear, it can be calibrated by adjusting the proportional coefficient of the sensor; if the error is nonlinear, it can be compensated by using methods such as polynomial fitting. After calibration, test again to verify the calibration effect.

[0047] Laser Doppler velocimetry technology has extremely high measurement accuracy and can accurately measure the moving speed of an object. By comparing with the high-precision laser Doppler velocimeter 9, the measurement accuracy of the mileage sensor 7 can be accurately evaluated. In practical applications, the measurement accuracy of the laser Doppler velocimeter 9 can reach the micron level or even higher, which can meet the needs of high-precision calibration of the mileage sensor 7. At the same time, the accuracy of the data acquisition and processing system will also affect the overall accuracy of the system. In this system, high-speed, high-precision data acquisition cards and computer software are used to accurately process and analyze the collected data, thereby improving the measurement accuracy of the system;

[0048] The laser Doppler velocimeter 9 does not come into direct contact with the object being measured, does not interfere with the movement of the object, and is not affected by the surface condition of the object. This non-contact measurement method can avoid problems such as wear and error accumulation that may occur in traditional contact measurement methods, and improve the reliability and stability of the measurement. For some special objects being measured, such as high-speed rotating objects, soft objects, or objects with uneven surfaces, the non-contact measurement method has obvious advantages. In this system, the laser Doppler velocimeter 9 can accurately measure various types of objects being measured, without being restricted by the surface condition and motion state of the object;

[0049] This system adopts automatic control technology, which can realize automatic control of the entire verification and calibration process, reduce the influence of human factors, and improve work efficiency. The control system can realize precise control of the speed and direction of the roller 5 through programming, and monitor and control the working status of the laser Doppler speed meter 9 and the mileage sensor 7 in real time. The data acquisition and processing system can automatically collect and process data and generate verification reports, which greatly improves work efficiency and measurement accuracy;

[0050] This system is applicable to various types of mileage sensors 7, including mechanical, electronic, optical, etc., and has broad application prospects. Different types of mileage sensors 7 have different working principles and output signals, but this system can adapt to the verification and calibration requirements of different types of mileage sensors 7 by adjusting the parameters and algorithms of the data acquisition and processing system. At the same time, this system can also be customized and developed according to different application requirements to meet the special needs of users.

[0051] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A mileage sensor verification and calibration system based on laser Doppler speed measurement, comprising a support platform (1), a laser Doppler speed meter (9), a roller (5), a mileage sensor (7), a standard object (6), a data acquisition and processing system, and a control system, characterized in that: The laser Doppler velocimeter (9) is used to measure the moving speed of an object; the roller (5) is used to carry the mileage sensor (7) and the standard object (6) to be tested and make them move at a stable speed; the data acquisition and processing system is used to collect output data of the laser Doppler velocimeter (9) and the mileage sensor (7) and to perform analysis and processing; the control system is used to control the speed and direction of the roller (5) and the working state of the laser Doppler velocimeter (9) and the mileage sensor (7); The laser Doppler velocimeter (9) is a core component of the system. When measuring the moving speed of an object, it has the advantages of high precision, high resolution, and non-contact measurement, and can accurately measure the moving speed of the object corresponding to the mileage sensor (7). The laser Doppler velocimeter (9) is usually composed of a laser, an optical system, a detector, and a signal processing circuit. The data acquisition and processing system is responsible for collecting output data of the laser Doppler velocimeter (9) and the mileage sensor (7), and performing analysis and processing. The data acquisition and processing system comprises a data acquisition card and computer software. The data acquisition card can collect analog signals or digital signals of the sensor in real time and transmit them to the computer for processing. The computer software can analyze the collected data, calculate errors, and generate a calibration report.

2. The mileage sensor verification and calibration system based on laser Doppler speed measurement according to claim 1 is characterized in that: The top of the support platform (1) is fixedly connected to a side plate (2) and a fixing frame (8); the side edge of the side plate (2) is fixedly connected to a motor (3); the output end of the motor (3) passes through the side plate (2) and is fixedly connected to a fixing shaft (4); the outer side of the fixing shaft (4) is fixedly connected to a roller (5); one end of the fixing shaft (4) is fixedly connected to a mileage sensor (7); the standard object (6) is connected to the outer side of the roller (5); and the upper end of the fixing frame (8) is fixedly connected to a laser Doppler velocimeter (9).

3. The mileage sensor verification and calibration system based on laser Doppler speed measurement according to claim 1 is characterized in that: The axis of the mileage sensor (7) is concentric with the axis of the roller (5).

4. The mileage sensor verification and calibration system based on laser Doppler speed measurement according to claim 1 is characterized in that: The marking length of the standard object (6) is precisely known.

5. The mileage sensor verification and calibration system based on laser Doppler speed measurement according to claim 1 is characterized in that: The data acquisition and processing system includes a data acquisition card and computer software. The data acquisition card is used to collect analog signals or digital signals from sensors in real time and transmit them to a computer. The computer software is used to analyze the collected data, calculate errors and generate a calibration report.

6. The mileage sensor verification and calibration system based on laser Doppler speed measurement according to claim 1 is characterized in that: The formula of the measurement error of the mileage sensor (7) is: error=[measurement value of the mileage sensor (7)-measurement value of the laser Doppler velocimeter (9)×time] / measurement value of the laser Doppler velocimeter (9)×time×100%.

7. The mileage sensor verification and calibration system based on laser Doppler speed measurement according to claim 1 is characterized in that: The surface of the standard object (6) is provided with equidistant scale marks.

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