Speed measurement method and system based on light and shadow changes

Abstract

The invention provides a speed measurement method and system based on shadow change, and the method comprises the steps: S1, irradiating a to-be-measured object through a continuously-arranged divergent light source, so as to enable the to-be-measured object to generate continuous shadow change; s2, acquiring height information of the light source, and measuring distance information between the light source and the measured object; s3, capturing and recording shadow information of the measured object; s4, extracting shadow vertex position change data of the measured object to obtain a relation between shadow speed and object speed; s5, randomly selecting a speed measurement point in the shadow area, the speed of the shadow being the first component speed of the measured object, S6, measuring a first rotation angle of the measured object around the divergent light source and a second rotation angle of the shadow of the measured object around the divergent light source; s7, deriving a second component velocity of the measured object based on the velocity measurement point; and S8, finally obtaining the actual operation speed of the measured object. The method can make up the defects of radar speed measurement and monocular camera speed measurement in actual movement speed measurement.

Description

Technical Field

[0001] This invention belongs to the field of speed measurement technology, and particularly relates to a speed measurement method and system based on changes in light and shadow. Background Technology

[0002] Currently, speed measurement methods used in automobile testing include: 1. Fifth-wheel speedometers, which use an additional wheel and measuring device to measure speed; 2. Photoelectric speed measuring instruments, which are non-grounded speed measuring instruments that use spatial filtering principles to detect vehicle speed; 3. GPS-based speed measurement systems, which mainly include a GPS receiver and a data acquisition system. In addition, there are general highway speed measurement devices, such as: 1. Radar speed measurement, mainly based on the Doppler effect. When the electromagnetic waves emitted by radar encounter a moving object (such as a car), the frequency of the reflected electromagnetic waves changes, and this frequency change is proportional to the velocity component of the object in the direction of the radar beam; 2. Monocular camera speed measurement, which calculates the speed by analyzing the positional changes of the target object in consecutive image frames.

[0003] Ground-based speed measuring instruments require the fifth wheel to be in constant contact with the ground during testing, and slippage is not allowed. This limits the range of test road types and is not conducive to the implementation of tests for off-road vehicles. Photoelectric speed measuring instruments rely on internal spatial filter sensors to receive light reflected from the ground and collect signals. However, on icy and snowy roads and wet HBS (Anti-lock Braking System) performance test surfaces, the low-adhesion surface cannot achieve good light reflection, resulting in signal loss and instrument failure. GPS-based speed measurement systems are expensive, and are generally only used by professional testing institutions and research institutes. Radar speed measurement and monocular camera speed measurement have limitations. Due to mechanical clearances or angle settings, the movement of a car may not be linear. Radar and monocular cameras can only measure the speed in one direction (partial speed) and cannot accurately measure the actual speed in the direction of movement. Summary of the Invention

[0004] The purpose of this application is to provide a speed measurement method and system based on changes in light and shadow. This application can overcome the shortcomings of radar speed measurement and monocular camera speed measurement in measuring actual moving speed.

[0005] To achieve the above objectives, one aspect of this application provides a speed measurement method based on changes in light and shadow, comprising the following steps: S1: Illuminate the moving object using at least one continuously arranged divergent light source to produce continuous shadow changes on the object. S2: Obtain the height information of the light source and measure the distance information between the light source and the object being measured in real time; ; S3: Based on the height information and the distance information, capture and record the shadow information of the object being measured; S4: Based on the shadow information, extract the change data of the shadow vertex position of the measured object, and obtain the relationship between the shadow velocity and the object velocity as follows: ; ; Where H is the height of the light source, and h is the height of the object being measured. The length of the shadow cast by the object being measured. Let be the distance from the object being measured to the light source, and let i be the time interval. Let be the longitudinal velocity of the shadow vertex. The velocity of the object; S5: Select any velocity measurement point n in the shaded area and calculate the rate of change of the shadow at point n. The calculation formula is as follows: ; in, The first component of the velocity of the object being measured; S6: Measure the first rotation angle of the object around the diverging light source when the object passes by the object; measure the second rotation angle of the shadow of the object around the diverging light source when the shadow of the object passes by the object. S7: Based on the speed measuring point n, the following is derived: ; in, The second rotation angle, The change can be obtained by dividing the time t. , The second component of the velocity of the object being measured; S8: Finally, the actual running speed of the measured object is obtained. .

[0006] Preferably, S4 further includes: The acceleration relationship of the measured object is: ; in, The acceleration of the object being measured. This represents the acceleration of the shadow vertex.

[0007] Preferably, S5 includes: The velocity measuring point n rotates around the object being measured and moves longitudinally, and the longitudinal movement is the line connecting the object being measured and the divergent light source.

[0008] Preferably, S6 includes: Using the motion of the object under test as a baseline, the rotational motion of the object under test is converted into the rotational motion of the shadow of the object under test around the object under test, so as to measure the first rotation angle and the second rotation angle.

[0009] Preferably, S8 further includes: Differentiate the time interval t to calculate the actual acceleration of the measured object. The formula is as follows: ; in, For the first acceleration, For the first acceleration, .

[0010] Preferably, when multiple shadow areas are generated by continuously arranged divergent light sources, a shadow threshold is set to shield the influence of adjacent divergent light sources. The shielding method is as follows: S01: Calculate the overall shadow level. The formula is as follows: All shadow pixels Mean; All shadow pixels Standard deviation; S02: Set the floating threshold, and its floating range is: ； in, The coefficient is used to select values. S03: Remove the shaded area; the decision function is: ; ; The decision function is used to remove light shadows.

[0011] Preferably, when multiple shadow areas are generated by continuously arranged divergent light sources, the influence of adjacent divergent light sources is shielded by the depth contrast between shadows. The shielding method is as follows: S04: Use an end-to-end convolutional neural network to detect shadow regions; The convolutional neural network supports shadows and complex boundaries; S05: When a shadow area is detected, eliminate the shadow.

[0012] Preferably, S3 includes: the test form is point measurement or interval measurement.

[0013] Preferably, the point measurement is used to calculate the instantaneous velocity based on the change in shadow at the measurement point when the object being measured passes through a predetermined independent measurement point; The interval measurement is used to calculate the velocity change of the measured object within the entire measurement interval based on the shadow change as the measured object passes through a set continuous measurement interval.

[0014] Another aspect of this application provides a speed measurement system based on light and shadow changes, using the aforementioned generation method, comprising: a light source module configured to provide a measurement light source; a height measurement module configured to measure the height information of the light source; a distance measurement module configured to measure the distance information between the light source and the object being measured; a camera module configured to capture the light and shadow information of the object being measured; a motion state detection module configured to measure the running angle of the object being measured; a signal transmission and storage module configured to receive and store the height information, distance information, light and shadow information, and running angle; and a light and shadow speed measurement module configured to calculate preset measurement parameters based on the height information, distance information, light and shadow information, and running angle. The display and recording module is configured to receive the final calculation results.

[0015] The technical solution provided in this application can achieve the following beneficial effects: 1. This application utilizes the geometric projection relationship between a continuously arranged divergent light source and the object being measured. By capturing shadow changes in real time and combining the height and distance information of the light source, the velocity and acceleration are calculated. This avoids the cumbersome steps of relying on complex targets or multi-sensor fusion in traditional velocity measurement methods. It can achieve continuous, real-time, and high-precision measurement of object motion under single or multiple light source conditions.

[0016] 2. This application not only supports the measurement of the linear motion speed of objects, but also, when there is relative rotation, collision or complex trajectory between the object and the light source, it can obtain the actual running speed and acceleration by introducing compensation calculations of rotation angle and shadow offset, thus making it suitable for a variety of complex motion scenarios, such as sports training, industrial assembly line monitoring, traffic detection, etc.

[0017] 3. This application proposes a shadow screening and elimination method based on statistical thresholds and convolutional neural networks for scenarios with interference from multiple light sources and multiple shadow areas. This effectively avoids artifact interference from adjacent light sources and improves the reliability of shadow detection. Simultaneously, through ambient light suppression and multi-source data fusion mechanisms, the system exhibits good adaptability and stability both indoors and outdoors, during day and night, and in strong light environments. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of light and shadow-based velocity measurement provided in an embodiment of this application; Figure 2 This is a schematic diagram of the illumination provided in the embodiments of this application using a diverging light source; Figure 3 This is a schematic diagram of the path movement of the object under test provided in an embodiment of this application; Figure 4 This is a schematic diagram of the connection between the object under test and the light source provided in an embodiment of this application; Figure 5 This is a schematic diagram of light and shadow velocity measurement provided in an embodiment of this application; Figure 6 This is a schematic diagram of interval measurement provided in an embodiment of this application; Figure 7 This is a schematic diagram of point measurement provided in an embodiment of this application; Figure 8 This is a schematic diagram of the speed measurement system structure provided in the embodiments of this application. Detailed Implementation

[0020] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0021] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0022] The speed measurement method proposed in this application is not limited to any particular object. As long as the environmental conditions are suitable and the equipment is complete, speed measurement can be performed regardless of the location, object, road surface condition, or whether the route is straight. In other words, this method can measure speed as long as the necessary conditions are met, and it is not limited to speed measurement in automobile testing. This application only uses automobiles as an example. Secondly, this method solves the error caused by the ground-based measurement of the fifth wheel in the fifth-wheel speed measurement, such as the fifth wheel bouncing and slipping, while this method is a non-grounded measurement. Then, it solves the problem that photoelectric speed measurement relies on light reflection and is limited by the different effects of road surface wetness on light, even though it is a non-grounded measurement. Finally, it solves the shortcomings of GPS positioning speed measurement systems in terms of high cost and high price. This application can make up for the deficiencies of radar speed measurement and monocular camera speed measurement in measuring actual moving speed.

[0023] This embodiment provides a speed measurement method based on light and shadow. When a car passes through a continuously arranged array of divergent light sources, it produces continuous changes in light and shadow. The car is used as the object being measured. When the object moves, it produces planar motion (taking the outer edge of the shadow as an example). The free motion law of this point is to rotate around the object and move longitudinally relative to it, that is, to move along the line connecting the object and the light source.

[0024] First, under any light source, when an object moves towards the light source, the speed measurement method is as follows: A light source is used to illuminate the moving object under test, so that the object under test produces continuous changes in light and shadow. Obtain the height information of the light source; Real-time measurement of the distance information between the light source and the object being measured; Based on the height information and the distance information, capture and record the light and shadow information of the object under test; Based on the light and shadow information, the change data of the position of the shadow vertex of the object under test is extracted to calculate the running speed of the object under test.

[0025] Specifically, such as Figure 1 As shown, the following relationship can be obtained: ; Where H is the height of the light source, and h is the height of the object being measured. The length of the shadow cast by the object being measured. Let i be the distance from the object being measured to the light source, and i be the time interval. Since H and h are known quantities, the equation... By differentiating the time values ​​at both ends, the longitudinal velocity of the shadow vertex can be determined: ; in, Let be the longitudinal velocity of the shadow vertex. The velocity of the object being measured; The acceleration relationship can also be derived as follows: ; in, Let x be the acceleration of the shadow vertex. This is the acceleration of the object being measured.

[0026] In another example, due to the specific conditions, there is a possibility of the measured object colliding with the light source, so a divergent light source is used, such as... Figure 2 As shown, where, The velocity of the object being measured in its direction of motion. Let t represent the distance between the object being measured and the light source t seconds ago. Let t be the distance between the object being measured and the light source after t seconds. The longest shadow distance of the object measured t seconds ago is given. Let t be the longest shadow distance of the object being measured after t seconds. Let t be the vertex of the longest shadow distance of the object being measured t seconds ago. Let t be the vertex of the longest shadow distance of the object being measured after t seconds. The small central circle represents the diffused light source, and the large central circle represents the illumination range of the diffused light source. and These are the first and second rotation angles around the diverging light source, respectively, when the object being measured and its shadow pass through the object. It should be noted that, with the motion of the object being measured as the baseline, based on the geometric equilibrium condition, we can obtain... = This is equivalent to converting the rotation of the object being measured into the rotation of the shadow of the object around the object, which facilitates the measurement of the rotation angle. A specific point in the shaded area is taken as the research object.

[0027] It should also be noted that the free motion of any point in the shadow area follows the law of rotation around the object being measured and longitudinal motion, and this longitudinal motion has a special characteristic—it moves along the line connecting the object being measured and the divergent light source. This means that any cross-sectional line passing through the divergent light source within the illumination range of the light source can be considered as a special motion in the above example. However, unlike the example above, the motion of the object being measured is no longer directed towards the light source, but it still reflects the motion state of the object being measured.

[0028] In this example, the speed measurement method is as follows: S1: Illuminate the moving object using at least one continuously arranged divergent light source to produce continuous shadow changes on the object. S2: Obtain the height information of the light source and measure the distance information between the light source and the object being measured in real time; ; S3: Based on the height information and the distance information, capture and record the shadow information of the object being measured; S4: Based on the shadow information, extract the change data of the shadow vertex position of the measured object, and obtain the relationship between the shadow velocity and the object velocity as follows: ; ; Where H is the height of the light source, and h is the height of the object being measured. The length of the shadow cast by the object being measured. Let be the distance from the object being measured to the light source, and let i be the time interval. Let be the longitudinal velocity of the shadow vertex. The velocity of the object; S5: Select any velocity measurement point n in the shaded area and calculate the rate of change of the shadow at point n. The calculation formula is as follows: ; in, This refers to the first component of the velocity of the object being measured; specifically, Figure 2 This diagram illustrates the shadow formation structure when a divergent light source illuminates an object under test, showing the correspondence between the object under test, the divergent light source, and the shadow path. Figure 3 Is Figure 2 Based on this, the measurement path corresponding to the direction of illumination is transformed, that is... Go to The corresponding path is marked with points after the path changes. , Figure 4 This is a further step from Figure 3 Detailed geometric relationships are depicted separately. and The relative positions and geometric correspondences of the measured object and the diverging light source along the line connecting them are used to clearly represent the spatial constraints between the two points, the light source, and the measured object. The rate of change of the shadow is no longer determined by... Figure 1 The obtained velocity and acceleration of the measured object are not the velocity and acceleration of the measured object relative to the diverging light source during its movement, but rather the velocity of the measured object relative to the diverging light source during its movement, and a changing component of velocity during the movement of the measured object. .

[0029] S6: Measure the first rotation angle of the measured object around the diverging light source when the measured object passes by the measured object; When the shadow of the object being measured passes through the object, the second rotation angle of the shadow of the object being measured around the diverging light source is measured. in, For the second rotation angle, The change can be obtained by dividing the time t. ; S7: From the kinematic relationships, we can deduce that: Due to the second rotation angle It can be measured that, for The change can be obtained by dividing the time t. , The second component velocity of the object being measured is given.

[0030] S8: Finally, the actual running speed of the measured object is obtained. .

[0031] Furthermore, by differentiating with respect to time t, the actual acceleration of the measured object can also be calculated: ,in, For the first acceleration, For the first acceleration, .

[0032] The above method is not limited to measuring linear motion, but can be used to measure velocity in any direction of motion. If there are enough divergent light sources, velocity measurement can be carried out indefinitely. However, due to the continuous setting of the light source, multiple shadow areas will inevitably be generated. Among them, the influence of adjacent light sources is the most severe, while non-adjacent light sources only cast very shallow shadows. Setting a certain shadow threshold or the depth contrast between shadows can shield the influence of adjacent light sources.

[0033] This example provides a shadow removal method based on a shadow threshold, including the following steps: S01: Calculate the overall shadow level. The formula is as follows: All shadow pixels Mean; All shadow pixels Standard deviation; S02: Set the floating threshold, and its floating range is: ； in, The coefficient is used to select values. S03: Remove the shaded area; the decision function is: ; ; The decision function is used to remove light shadows.

[0034] This example provides a shadow removal method based on depth contrast between shadows, including the following steps: S04: Use an end-to-end convolutional neural network to detect shadow regions; The convolutional neural network supports shadows and complex boundaries; S05: When a shadow area is detected, eliminate the shadow.

[0035] like Figure 5 As shown, when the object being measured moves from the light source illumination area into the overlapping area of ​​adjacent light sources, it exhibits the following characteristics: 1. Continuity of shadow changes under the same light source illumination; 2. Discontinuity of shadows under different light sources illumination—from one shadow area to two shadow areas, and the newly appearing shadow forms a considerable angle with the shadow being detected.

[0036] This example provides a complete testing procedure. First, wait for the measurement to begin. To ensure the object under test is fully illuminated within the measurement area and to prevent incorrect height information from being included in the measurement, check for ghosting. If no ghosting occurs, proceed with the measurement normally. If ghosting occurs, use continuity conditions to distinguish between captured and uncaptured ghosting, and identify and process the ghosting information. If the uncaptured ghosting is shallow, continue collecting information on the captured shadow; if the uncaptured ghosting is deep, delete the captured shadow data. Also, detect and record the distance on the plane between the shadow and the corresponding point on the object at its highest point, as well as the angle of this line relative to the object's direction of movement. This detection and recording is performed twice, with an additional measurement of the distance between the corresponding point and the light source on the plane during the second measurement. Check if more than one data entry record is needed. If not, the data volume is insufficient for calculation, and another measurement is required; if more is needed, continue calculating Vr, Ve, and Va. If acceleration measurement is also required, continue the calculation, and repeat the cycle for the next calculation.

[0037] In one example, the test format is divided into point measurement and interval measurement, where the interval measurement format is as follows: Figure 6 As shown, interval measurement can measure the velocity change of the object being measured throughout the entire measurement process.

[0038] Point measurement format as follows Figure 7 As shown, point measurement can measure the velocity of the object at a certain point.

[0039] Specifically, point measurement is used to calculate the instantaneous velocity of an object at a predetermined single measurement point by utilizing the changes in shadow cast by a light source. In practical applications, the light source and camera equipment can be fixed to the ground or a reference object, allowing the object to pass through a specific illuminated area. As the object moves past the measurement point, the system collects the instantaneous change data of the shadow at that point. For example, in a highway speed measurement scenario, point measurement can use a fixed-point measurement camera arranged in conjunction with a divergent light source to calculate the instantaneous speed of a vehicle in real time as it passes by.

[0040] Correspondingly, interval measurement is used to calculate the velocity change curve of the measured object within a set continuous measurement interval, based on the continuous shadow changes within that interval, thereby obtaining the overall acceleration and deceleration characteristics of the measured object. In practical applications, interval measurement can be achieved by deploying multiple continuous illumination measurement units. The light and shadow data between each unit are correlated to form time series data, which is then used for velocity fitting and acceleration analysis through a deep learning model.

[0041] For example, in tests of rail vehicles, unmanned vehicles, or runway motion, on-board measuring equipment or UAV measuring equipment can be used to arrange multiple divergent light sources along the motion path, and the speed change pattern of the moving object in the entire test range can be calculated by continuously shooting shadow data.

[0042] By combining the two measurement modes mentioned above, the system can simultaneously support instantaneous speed detection and full-process speed analysis, thereby achieving more flexible and accurate speed measurement results in different testing scenarios.

[0043] This example provides a speed measurement system based on changes in light and shadow, using the speed measurement method described above, such as... Figure 8 As shown, the system includes: a light source module 10 configured to provide a measurement light source; a height measurement module 20 configured to measure the height information of the light source; a distance measurement module 30 configured to measure the distance information between the light source and the object being measured; a camera module 40 configured to capture the light and shadow information of the object being measured; a motion state detection module 50 configured to measure the running angle of the object being measured; a signal transmission and storage module 60 configured to receive and store height information, distance information, light and shadow information, and running angle; a light and shadow speed measurement module 70 configured to calculate preset measurement parameters based on the height information, distance information, light and shadow information, and running angle; and a display and recording module 80 configured to receive the final calculation results.

[0044] Specifically, when the object under test is being tested, the light source module provides several measuring light sources, and the height measurement module of the light source provides its height information. The distance measurement module provides the relative distance information of the object under test relative to the light source. The camera captures the light and shadow information of the object under test, and the motion state detection module of the object under test measures the running angle of the object at this time. These data are transmitted to the input signal transmission and storage module, and finally to the light and shadow speed measurement module, where the data is processed. Finally, the measurement parameters are calculated based on the height parameters of the object under test, and finally transmitted to the display and recording module.

[0045] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for measuring speed based on light and shadow changes, characterized in that, The method comprises the following steps: S1: using at least one continuously arranged divergent light source to irradiate a measured object in a moving state, so that the measured object produces continuous shadow changes; S2: acquiring height information of the light source and measuring distance information between the light source and the measured object in real time; S3: based on the height information and the distance information, capturing and recording shadow information of the measured object; S4: based on the shadow information, extracting shadow vertex position change data of the measured object, and obtaining a relationship between shadow speed and object speed as: ； ； Where H is the height of the light source, h is the height of the measured object, is the shadow length of the measured object, is the distance from the measured object to the light source, i is the time, is the longitudinal velocity of the shadow vertex, is the velocity of the object; S5: at an optional speed measurement point n in the shadow area, calculating a change speed of the shadow at the point n, and the calculation formula is: ； wherein, is the first component velocity of the object under test; S6: measuring a first rotation angle of the measured object around the divergent light source when the measured object passes through the measured object, and measuring a second rotation angle of the shadow of the measured object around the divergent light source when the shadow of the measured object passes through the measured object; S7: based on the speed measurement point n, derive: ; wherein is a second rotation angle, The change amount of divided by time t can obtain , is a second component velocity of the measured object; S8: The actual running speed of the measured object is finally obtained .

2. The method of claim 1, wherein, S4 further comprises: An acceleration relationship of the measured object is: ； wherein is the acceleration of the object being measured, is the acceleration of the shadow apex.

3. The method of claim 1, wherein S5 Comprising: The speed measurement point n rotates around the measured object and makes a longitudinal movement, and the longitudinal movement is a line connecting the measured object and the divergent light source.

4. The method of claim 1, wherein S6 Comprising: Taking the movement of the measured object as a baseline, the rotational movement of the measured object is converted into a rotational movement of the shadow of the measured object around the measured object, so as to measure the first rotation angle and the second rotation angle.

5. The method of claim 1, wherein, S8 further comprises: Deriving with respect to time t to calculate an actual running acceleration of the measured object, and the calculation formula is: ； wherein is the first partial acceleration, is the first partial acceleration, .

6. The method of claim 1, wherein, When multiple shadow areas are generated by continuously arranging the divergent light sources, a shadow threshold is set to shield the influence of adjacent divergent light sources, and the shielding method is as follows: S01: calculating an overall shadow level, and the calculation formula is: all the shadow pixels mean; all the shadow pixels standard deviation; S02: setting a floating threshold, and the floating interval is: ； wherein is a value coefficient; S03: cutting off the shadow, and the decision function is: ; ; Removing the shallow shadow through the decision function.

7. The method of claim 1, wherein, When multiple shadow areas are generated by continuously arranging the divergent light sources, the influence of adjacent divergent light sources is shielded through depth contrast between shadows, and the shielding method is as follows: S04: detecting a shadow area using an end-to-end convolutional neural network; The convolutional neural network supports shadows and complex boundaries; S05: when the shadow area is detected, the shadow is eliminated.

8. The method of claim 1, wherein, S3 comprises: The test form is point measurement or interval measurement.

9. The method of claim 8, wherein, Comprising: The point measurement is used to calculate an instantaneous speed according to shadow changes at a measurement point when the measured object passes through a predetermined independent measurement point; The interval measurement is used to calculate a speed change of the measured object in the entire measurement interval based on shadow changes when the measured object passes through a set continuous measurement interval.

10. A light shadow change based speed measurement system using the speed measurement method of any one of claims 1-9, characterized by, Comprising: A light source module configured to provide a measurement light source; A height measurement module configured to measure height information of the light source; A distance measurement module configured to measure distance information between the light source and the measured object; A camera module configured to capture light and shadow information of the measured object; A motion state detection module configured to measure a running angle of the measured object; A signal transmission and storage module configured to receive and store the height information, the distance information, the light and shadow information, and the running angle; The light-shadow speed measurement module is configured to calculate preset measurement parameters according to the height information, the distance information, the light-shadow information and the running angle. The display and recording module is configured to receive the final calculation results.

Images