Rotating speed detection method and device, electronic equipment and storage medium
By setting marks on rotating objects and shooting videos with an imaging device, and calculating the rotation speed based on the visual extension length, the problem of speed sensors being easily disturbed in the prior art is solved, and accurate measurement and wide application are achieved.
Patent Information
- Application Number
- CN202311699720.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-12
- Publication Date
- 2025-06-13
Smart Images
Figure CN120142690A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of detection, and particularly to a rotational speed detection method, device, electronic device, and storage medium. Background Art
[0002] Measuring the rotational speed of a rotating object is an inevitable task in the industrial field. For example, in a motor control system, it is often necessary to measure and control the rotational speed of the motor to improve the performance of the motor and enhance the control accuracy. On the other hand, for the idler drive system of a belt conveyor, realizing the rotational speed monitoring of the idler can prevent the idler from slipping or catching fire due to bearing jamming, further improving the safety of coal mine production.
[0003] Existing electromechanical rotational speed measurement means or devices include photoelectric sensors, magnetoelectric sensors, and Hall sensors.
[0004] For a device using a photoelectric tachometer to measure speed, the photoelectric induction disk is synchronously linked with the rotating object. By connecting the signal input end of the speed measurement device to the photoelectric induction disk and cooperating with the speed measurement device and control system for measuring the rotational speed of the photoelectric induction disk, the rotational speed measurement of the rotating object is achieved. For rotational speed sensors such as magnetoelectric sensors and Hall sensors, the rotational speed sensor needs to be fixed on the surface of the rotating object. For example, by borrowing the indentation on the surface of the rotating object and placing the rotational speed sensor on the indentation rotation track to measure the rotational speed of the rotating object.
[0005] Therefore, in the existing electromechanical rotational speed measurement methods, it is necessary to synchronously link the rotational speed sensor with the rotating object or directly install the rotational speed sensor on the rotating object. Therefore, the rotational speed sensor measures during the rotation process, and thus the measurement accuracy is extremely vulnerable to factors such as strong external vibrations and electromagnetic interference. In addition, when there are influences such as wire routing, power supply, or gas, the placement method of the rotational speed sensor needs to be changed, so it is difficult to have a relatively wide range of applications. Summary of the Invention
[0006] Based on this, in view of the technical problem in the prior art that the rotational speed measurement requires the rotational speed sensor to be synchronously linked with the rotating object or directly installed on the rotating object, it is necessary to provide a rotational speed detection method, device, electronic device, and storage medium.
[0007] The present invention provides a rotational speed detection method, including:
[0008] Obtaining the rotation parameters of the rotating object and / or the marker parameters of the marker moving with the rotating object on the surface of the rotating object, and obtaining the camera parameters of the camera device for photographing the marker;
[0009] Obtain a video of the marker rotating with the rotating object captured by the imaging device, and extract key frames from the video;
[0010] Obtain the visual extension length of the marker in the key frames, where the visual extension length is the length of the visual extension of the marker caused by the dynamic blur effect;
[0011] Calculate the rotation speed of the rotating object according to the visual extension length, the rotation parameter, the marker parameter, and the imaging parameter.
[0012] Further, the rotation parameter is the pixel length of the rotation radius of the rotation axis, the marker parameter is the pixel length of the marker, and the imaging parameter is the number of frames of the imaging device. Calculating the rotation speed of the rotating object according to the visual extension length, the rotation parameter, the marker parameter, and the imaging parameter includes:
[0013] Calculate the rotation speed of the rotating object according to the visual extension length, the pixel length of the rotation radius, the pixel length of the marker, and the number of frames.
[0014] Even further, the rotation speed is the angular velocity. Calculating the rotation speed of the rotating object according to the visual extension length, the pixel length of the rotation radius, the pixel length of the marker, and the number of frames includes:
[0015] Calculate the angular velocity of the rotating object as where f is the number of frames, L is the visual extension length, d is the pixel length of the marker, and R is the pixel length of the rotation radius.
[0016] Even further, obtaining the rotation parameter of the rotating object and / or the marker parameter of the marker moving with the rotating object on the surface of the rotating object includes:
[0017] Obtain a photo of the rotating object when it is stationary captured by the imaging device, and extract the pixel length of the rotation radius of the rotation radius and / or the pixel length of the marker from the photo.
[0018] Further, the rotation parameter is the rotation radius of the rotation axis, the marker parameter is the physical length of the marker, and the imaging parameter is the number of frames of the imaging device. Calculating the rotation speed of the rotating object according to the visual extension length, the rotation parameter, the marker parameter, and the imaging parameter includes:
[0019] Obtain the pixel length of the rotation radius of the rotation radius and / or the pixel length of the marker;
[0020] Taking the ratio of the rotation radius to the pixel length of the rotation radius as the magnification factor, or taking the ratio of the physical length of the marker to the pixel length of the marker as the magnification factor;
[0021] Multiplying the visually extended length by the magnification factor to obtain the actual visually extended length;
[0022] Calculating the rotational speed of the rotating object according to the actual visually extended length, the rotation radius, the physical length of the marker of the marker, and the number of frames.
[0023] Further, the rotational speed is the angular velocity, and calculating the rotational speed of the rotating object according to the actual visually extended length, the rotation radius, the physical length of the marker of the marker, and the number of frames includes:
[0024] Calculating the angular velocity of the rotating object as where f is the number of frames, L1 is the actual visually extended length, d1 is the physical length of the marker of the marker, and R1 is the rotation radius.
[0025] Still further, the marker is a coating, a sticker, a marker point, or a texture.
[0026] The present invention provides a rotational speed detection device, including:
[0027] A parameter acquisition module, configured to acquire the rotation parameters of a rotating object and / or the marker parameters of a marker moving on the surface of the rotating object along with the rotating object, and acquire the imaging parameters of an imaging device for imaging the marker;
[0028] A key frame acquisition module, configured to acquire a video of the marker rotating with the rotating object by the imaging device, and extract key frames from the video;
[0029] A visually extended length acquisition module, configured to acquire the visually extended length of the marker in the key frames, where the visually extended length is the length of the visual extension of the marker caused by the dynamic blur effect;
[0030] A rotational speed calculation module, configured to calculate the rotational speed of the rotating object according to the visually extended length, the rotation parameters, the marker parameters, and the imaging parameters.
[0031] The present invention provides an electronic device, including:
[0032] At least one processor; and,
[0033] A memory communicatively connected to at least one of the processors; wherein,
[0034] The memory stores instructions executable by at least one of the processors, and the instructions are executed by at least one of the processors to enable at least one of the processors to execute the rotational speed detection method as described above.
[0035] The present invention provides a storage medium that stores computer instructions, which are used to execute all steps of the rotational speed detection method as described above when a computer executes the computer instructions.
[0036] In the present invention, a marker is set on a rotating object, a video of the marker rotating with the rotating object is taken, and the rotational speed of the rotating object is calculated based on the length of the visual extension caused by the dynamic blur effect of the marker. The present invention uses the method of marker recognition to monitor the rotational speed of the rotating object in real time, and realizes accurate measurement of the rotational speed by optimizing the combination of software and hardware. The present invention does not need to set a sensor on the rotating object, but determines the rotational speed of the rotating object through the imaging method, avoiding contact with the rotating object and the influence of factors such as strong vibration and electromagnetic interference. At the same time, since only a marker is set on the rotating object, there is no need to supply power and route wires to the marker, and there is no need to change the rotating object, so it has a better application space. Even when the installation method of the device needs to be changed, it is very convenient to replace and adjust the position of the marker. BRIEF DESCRIPTION OF THE DRAWINGS
[0037] Figure 1 is a flowchart of the operation of a rotational speed detection method according to an embodiment of the present invention;
[0038] Figure 2 is a flowchart of the operation of a rotational speed detection method according to another embodiment of the present invention;
[0039] Figure 3 is a photo of a rotating object and a marker with a roller as an example in a stationary state;
[0040] Figure 4 is Figure 3 the photo after binarization processing;
[0041] Figure 5 are key frames of the same rotating object at different rotational speeds, and the sectors represent the visual extension caused by motion blur of the marker;
[0042] Figure 6 The result of stacking the Figure 5 sectors in, and the arc length has an obvious increasing property;
[0043] Figure 7 is Figure 6 the schematic diagram of the geometric principle;
[0044] Figure 8 is the rotation angle corresponding to the measured visual extension length;
[0045] Figure 9 This is the flowchart of the working process of a method for measuring the rotational speed of a fixed shaft according to the best embodiment of the present invention;
[0046] Figure 10 This is the schematic diagram of a rotational speed detection device according to an embodiment of the present invention;
[0047] Figure 11 This is the schematic diagram of the hardware structure of an electronic device according to the present invention; Detailed implementation manners
[0048] The following further describes the detailed implementation manners of the present invention with reference to the accompanying drawings. The same components are denoted by the same reference numerals. It should be noted that the terms "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to the directions in the drawings, and the terms "inner" and "outer" respectively refer to the directions towards or away from the geometric center of a specific component.
[0049] As Figure 1 shown, this is the flowchart of the working process of a rotational speed detection method according to an embodiment of the present invention, including:
[0050] Step S101: Obtain the rotation parameters of the rotating object and / or the marker parameters of a marker moving with the rotating object on the surface of the rotating object, and obtain the imaging parameters of the imaging device for photographing the marker;
[0051] Step S102: Obtain the video of the marker rotating with the rotating object captured by the imaging device, and extract key frames from the video;
[0052] Step S103: Obtain the visual extension length of the marker in the key frame, where the visual extension length is the length of the visual extension of the marker caused by the dynamic blur effect;
[0053] Step S104: Calculate the rotational speed of the rotating object according to the visual extension length, the rotation parameters, the marker parameters, and the imaging parameters.
[0054] Specifically, the present invention can be applied to an electronic device with processing capabilities, such as a computer.
[0055] First, execute step S101 to obtain the rotation parameters of the rotating object and / or the marker parameters of a marker moving with the rotating object on the surface of the rotating object, and obtain the imaging parameters of the imaging device for photographing the marker.
[0056] Specifically, as Figure 3 and Figure 4 shown, place an easily observable marker 2 at a position on the surface of the rotating object 1 that moves with the rotating object. Among themFigure 3 The following are photos of the rotating object 1 and the marker 2 in a stationary state. Figure 4 for Figure 3 The binarized photo makes it easier to observe the outline of marker 2.
[0057] The marker may be a coating, sticker, marking point or texture of a fixed size. The coating may be colored paint of a specific color, fluorescent paint, etc. The sticker may be a barcode, QR code, color mark or other sticker with a specific shape, color or pattern. The marking point may be a mark made on the surface of the roller by ink, paint, laser engraving, etc. The texture may be a mark such as a notch, concave-convex texture, etc. that is provided by the roller or made manually.
[0058] The rotation parameters of the rotating object and the marker parameters of the marker are then measured.
[0059] The camera device is used to shoot the marker object rotating with the rotating object. The camera parameters of the camera device can be obtained by consulting the usage parameters of the camera device.
[0060] The rotation parameters, the marker parameters and the camera parameters are acquired by the electronic device by executing step S101, for example, the rotation parameters, the marker parameters and the camera parameters are uploaded to the electronic device.
[0061] Then, when the rotating object rotates, the camera device captures a video of the marker suspended along with the rotating object, and the electronic device executes step S102 to acquire the video and extract key frames from the video.
[0062] In some embodiments, the key frame is a video frame in which the marker in the video is not obstructed.
[0063] Then, step S103 is executed to obtain the visual extension length of the marker in the key frame, where the visual extension length is the length of the visual extension of the marker caused by the dynamic blur effect.
[0064] Since the camera frame rate is fixed, the marker 2 will be visually extended due to the motion blur effect, and the visual extension length is linearly positively correlated with the rotation speed. Figure 5 The key frames of the same rotating object 1 at different rotation speeds are shown. The rotation speed increases arithmetic steps from left to right. The sector area 3 represents the visual extension length of the marker 2.
[0065] like Figures 6 to 8 As shown, Figure 6 Will Figure 5 The result of superimposing the fan-shaped areas in the figure is that the arc length has an obvious increasing tendency. Figure 7 It is a schematic diagram of the geometric principle. Among them, the rotation angle corresponding to the pixel length d of the marker is β, and the rotation angle corresponding to the actual rotation length of the marker is α. Figure 8The rotation angle α+β corresponding to the measured visual extension length. From Figure 8 it can be seen that the rotation angle increases linearly.
[0066] Therefore, after obtaining the visual extension length, step S104 is executed to calculate the rotational speed of the rotating object according to the visual extension length, the rotation parameter, the marker parameter, and the camera parameter.
[0067] Specifically, after analyzing the equation of the visual extension length and the rotational speed, step S104 is executed to measure the rotational speed of the rotating object.
[0068] In the present invention, a marker is set on the rotating object, a video of the marker rotating with the rotating object is taken, and the rotational speed of the rotating object is calculated based on the length of the visual extension caused by the dynamic blur effect of the marker. The present invention uses the method of marker recognition to monitor the rotational speed of the rotating object in real time, and realizes accurate measurement of the rotational speed by optimizing the combination of software and hardware. The present invention does not need to set a sensor on the rotating object, but determines the rotational speed of the rotating object by means of photography, avoiding contact with the rotating object and the influence of factors such as strong vibration and electromagnetic interference. At the same time, since only a marker is set on the rotating object, there is no need to supply power and route wires for the marker, and there is no need to change the rotating object, so that it has a better application space. Even when the installation method of the device needs to be changed, the position of the marker can be easily replaced and adjusted.
[0069] As Figure 2 shown is a flowchart of a rotational speed detection method in another embodiment of the present invention, including:
[0070] Step S201, obtaining the rotation parameter of the rotating object and / or the marker parameter of the marker moving with the rotating object on the surface of the rotating object, and obtaining the camera parameter of the camera device for photographing the marker. The rotation parameter is the pixel length of the rotation radius of the rotation axis, the marker parameter is the pixel length of the marker, the camera parameter is the number of frames of the camera device, and the marker is a coating, a sticker, a marking point, or a texture.
[0071] In one embodiment, the obtaining the rotation parameter of the rotating object and / or the marker parameter of the marker moving with the rotating object on the surface of the rotating object includes:
[0072] Obtaining a photo of the rotating object taken by the camera device when it is stationary, and extracting the pixel length of the rotation radius of the rotation radius and / or the pixel length of the marker from the photo.
[0073] Step S202, obtaining a video of the marker rotating with the rotating object taken by the camera device, and extracting key frames from the video.
[0074] Step S203: Obtain the visual extension length of the marker in the key frame, where the visual extension length is the length of the visual extension of the marker caused by the dynamic blur effect.
[0075] Step S204: Calculate the rotation speed of the rotating object according to the visual extension length, the rotation parameter, the marker parameter, and the camera parameter.
[0076] Specifically, first execute Step S201 to obtain the rotation parameter of the rotating object and / or the marker parameter of the marker moving on the surface of the rotating object, and obtain the camera parameter of the camera device for photographing the marker. The rotation parameter is the pixel length of the rotation radius of the rotation axis, the marker parameter is the pixel length of the marker of the marker, the camera parameter is the number of frames of the camera device, and the marker is a coating, a sticker, a marking point, or a texture.
[0077] In one embodiment, the obtaining the rotation parameter of the rotating object and / or the marker parameter of the marker moving on the surface of the rotating object includes:
[0078] Obtain a photo of the rotating object taken by the camera device when it is stationary, and extract the pixel length of the rotation radius of the rotation radius and / or the pixel length of the marker of the marker from the photo.
[0079] Specifically, take a photo when the rotating object is stationary, use an object detection algorithm (You Only Look Once, YOLO), such as YOLOv5, to perform target recognition of the rotating object and the marker, draw the rotation axis and the marker area, and calculate the pixel length of the rotation axis radius and the pixel length of the marker.
[0080] The number of frames can be obtained by referring to the usage parameters of the camera device and uploaded to the electronic device.
[0081] After that, execute Step S202 to obtain the video of the marker rotating with the rotating object taken by the camera device, and extract the key frames from the video.
[0082] Then, execute Step S203 to obtain the visual extension length of the marker in the key frame, where the visual extension length is the length of the visual extension of the marker caused by the dynamic blur effect.
[0083] Specifically, use an object detection algorithm (You Only Look Once, YOLO), such as YOLOv5, to perform target recognition of the rotating object and the marker, draw the visual extension area, and calculate its pixel length as the visual extension length.
[0084] Then, perform step S204 to calculate the rotational speed of the rotating object according to the visual extension length, the rotation parameter, the marker parameter, and the camera parameter.
[0085] The present invention does not require a sensor to be provided on the rotating object, but determines the rotational speed of the rotating object by means of camera shooting, avoiding contact with the rotating object and the influence of factors such as strong vibration and electromagnetic interference. At the same time, the markers in this embodiment are easy to place and mark, without the need for power supply wiring for the markers, and without the need to modify the rotating object, enabling it to have a better application space. Even when the device installation method needs to be changed, the position of the marker can be easily replaced and adjusted.
[0086] In one embodiment, the calculating the rotational speed of the rotating object according to the visual extension length, the rotation parameter, the marker parameter, and the camera parameter includes:
[0087] Calculate the rotational speed of the rotating object according to the visual extension length, the pixel length of the rotation radius, the pixel length of the marker, and the number of frames.
[0088] Specifically, based on the equation of the visual extension length and the rotational speed, calculate the rotational speed of the rotating object according to the visual extension length, the pixel length of the rotation radius, the pixel length of the marker, and the number of frames.
[0089] This embodiment calculates the rotational speed of the rotating object based on the relationship between the visual extension length and the rotational speed, according to the visual extension length, the pixel length of the rotation radius, the pixel length of the marker, and the number of frames, and the calculation of the rotational speed is fast and simple.
[0090] In one embodiment, the rotational speed is the angular velocity, and the calculating the rotational speed of the rotating object according to the visual extension length, the pixel length of the rotation radius, the pixel length of the marker, and the number of frames includes:
[0091] Calculate the angular velocity of the rotating object as where f is the number of frames, L is the visual extension length, d is the pixel length of the marker, and R is the pixel length of the rotation radius.
[0092] Specifically, from the principle of the camera, it can be known that the shutter time of the key frame is During this period of time, by comparing the pixel length d of the marker and the visual extension length L, the extended displacement is obtained as L - d, and thus the pixel linear velocity of the marker can be obtained as or f(L - d), and combined with the pixel length R of the rotation radius, the angular velocity is obtained as
[0093] This embodiment provides specific equations for visual extension length and angular velocity, so as to quickly determine the angular velocity.
[0094] In one embodiment, the rotation parameter is the rotation radius of the rotation axis, the marker parameter is the physical length of the marker, the imaging parameter is the number of frames of the imaging device, and calculating the rotation speed of the rotating object according to the visual extension length, the rotation parameter, the marker parameter, and the imaging parameter includes:
[0095] Obtain the pixel length of the rotation radius of the rotation radius and / or the pixel length of the marker of the marker;
[0096] Take the ratio of the rotation radius to the pixel length of the rotation radius as the magnification factor, or take the ratio of the physical length of the marker of the marker to the pixel length of the marker as the magnification factor;
[0097] Multiply the visual extension length by the magnification factor to obtain the actual visual extension length;
[0098] Calculate the rotation speed of the rotating object according to the actual visual extension length, the rotation radius, the physical length of the marker of the marker, and the number of frames.
[0099] Specifically, first obtain the pixel length of the rotation radius of the rotation radius and / or the pixel length of the marker of the marker.
[0100] Specifically, the physical length of the marker of the marker can be measured by a measuring tool such as a tape measure, and the radius of the rotation axis is the distance from the rotation center of the rotating object to the geometric center of the marker, which can be measured by a measuring tool such as a tape measure. Then upload the rotation radius and the physical length of the marker of the marker to the electronic device. Use YOLOv5 for target recognition of the rotating object and the marker, draw the rotation axis and the marker area, and calculate the pixel length of the rotation axis radius and the pixel length of the marker.
[0101] Then, calculate the magnification factor n = rotation radius / pixel length of the rotation radius, or the magnification factor n = physical length of the marker / pixel length of the marker.
[0102] The visual extension length is the pixel length. Therefore, based on the magnification factor, multiply the visual extension length by the magnification factor to obtain the actual visual extension length.
[0103] Finally, based on the equation of the actual visual extension length and the rotation speed, calculate the rotation speed of the rotating object according to the actual visual extension length, the rotation radius, the physical length of the marker of the marker, and the number of frames.
[0104] In this embodiment, the visual extension length is first converted into the actual visual extension length, and the rotational speed of the rotating object is calculated directly based on the relationship between the actual visual extension length and the rotational speed, and the calculation of the rotational speed is quick and simple.
[0105] In one embodiment, the rotational speed is the angular speed, and calculating the rotational speed of the rotating object according to the actual visual extension length, the radius of rotation, the physical length of the marker of the marker, and the number of frames includes:
[0106] Calculating the angular speed of the rotating object as where f is the number of frames, L1 is the actual visual extension length, d1 is the physical length of the marker of the marker, and R1 is the radius of rotation.
[0107] Specifically, from the principle of the camera, it can be known that the shutter time of the key frame is During this period of time, by comparing the physical length d1 of the marker and the actual visual extension length L1, the actual extended displacement is obtained as L1 - d1, and thus the linear velocity of the marker can be calculated as or f(L1 - d1), combined with the radius of rotation R1, the rotational angular speed of the actual rotating object is obtained as
[0108] This embodiment provides a specific equation for the actual visual extension length and the angular speed of the rotating object, so as to quickly determine the angular speed of the rotating object.
[0109] Such as Figure 9 shown is the flowchart of the working method for measuring the rotational speed of a fixed axis in the best embodiment of the present invention, including:
[0110] Step S901, place an easily observable marker at a position on the surface of the rotating object that moves with the rotating object;
[0111] Step S902, measure the physical length of the marker, the radius of the rotating shaft, and the number of frames of the camera;
[0112] Step S903, use the camera to capture the running video of the rotating object, and retrieve the key frame in which the marker is not blocked from the video;
[0113] Step S904, analyze the visual extension caused by the dynamic blur effect of the marker in the key frame through marker capture to obtain the visual extension length;
[0114] Step S905, calculate the rotational speed in combination with the physical length of the marker, the radius of the rotating shaft, the number of frames of the camera, and the visual extension length.
[0115] This embodiment proposes a rotational speed measurement method based on video processing technology. This method uses a camera to capture a marker with characteristics and a fixed size on a rotating object, and then the computer can process the video of the marker rotating with the rotating object into a still image. Since the camera frame rate is fixed, according to the motion blur effect, the marker will have a visual extension, and the degree of extension is linearly positively correlated with the rotational speed. After analyzing the equation between the degree of extension and the rotational speed, this method can be used to measure the rotational speed of the rotating object.
[0116] Step S901, place an easily observable marker at a position on the surface of the rotating object that moves with the rotating object. The marker can be a coating, sticker, marking point or texture with a fixed size. The coating can be a colored paint, fluorescent coating, etc. of a specific color. The sticker can be a sticker with a specific shape, color or pattern such as a barcode, QR code, color mark, etc. The marking point can be a mark made on the surface of the idler roller by means of ink, paint, laser engraving, etc. The texture can be a mark such as a notch or uneven texture that comes with the idler roller or is made artificially.
[0117] Step S902, measure the physical length d1 of the marker, the radius R1 of the rotation axis and the camera frame rate f and provide them as inputs to the computer.
[0118] Specifically, the physical length of the marker can be measured by a measuring tool such as a tape measure. The radius of the rotation axis is the distance from the rotation center of the rotating object to the geometric center of the marker, which can be measured by a measuring tool such as a tape measure. The camera frame rate can be obtained by referring to the usage parameters.
[0119] Step S903, use the camera to shoot the running video of the rotation axis, and retrieve the key frame in which the marker is not blocked from the video and send the key frame to the computer.
[0120] Step S904, the computer analyzes the visual extension of the marker caused by the dynamic blur effect in the key frame through marker capture, and obtains the visual extension length L of the marker.
[0121] Specific method:
[0122] The computer uses YOLOv5 for target recognition of the rotating object and the marker, draws the rotation axis and the marker area, and calculates the pixel length R of the rotation axis radius and the pixel length d of the marker; draws the visual extension area and calculates its pixel length as the visual extension length L.
[0123] Step S905, the computer combines the physical length of the marker, the pixel length of the marker, the radius of the rotation axis, the length of the rotation axis radius, the camera frame rate and the visual extension length to calculate the rotational speed of the rotating object.
[0124] Specific method:
[0125] According to the principle of the camera, the shutter time of the key frame is During this period, by comparing the pixel length d of the marker and the visual extension length L, the extended displacement is obtained as L - d; thus, the pixel linear velocity of the marker can be calculated as Or f(L - d), and the angular velocity is The magnification factor This angular velocity is the rotational speed of the rotating object.
[0126] Alternatively, calculate the magnification factor n = rotation radius / pixel length of the rotation radius, or magnification factor n = physical length of the marker / pixel length of the marker. Calculate the actual visual extension length L1 = L * n. Calculate the angular velocity of the rotating object as Where f is the number of frames, L1 is the actual visual extension length, d1 is the physical length of the marker, and R1 is the rotation radius.
[0127] Based on the same inventive concept, as Figure 10 shown in the schematic diagram of a rotational speed detection device according to an embodiment of the present invention, including:
[0128] A parameter acquisition module 1001, configured to acquire the rotation parameters of the rotating object and / or the marker parameters of the marker moving with the rotating object on the surface of the rotating object, and acquire the camera parameters of the camera device for photographing the marker;
[0129] A key frame acquisition module 1002, configured to acquire the video of the marker rotating with the rotating object captured by the camera device, and extract key frames from the video;
[0130] A visual extension length acquisition module 1003, configured to acquire the visual extension length of the marker in the key frame, where the visual extension length is the length of the visual extension of the marker caused by the dynamic blur effect;
[0131] A rotational speed calculation module 1004, configured to calculate the rotational speed of the rotating object according to the visual extension length, the rotation parameters, the marker parameters, and the camera parameters.
[0132] In the present invention, a marker is set on a rotating object, and a video of the marker rotating with the rotating object is taken. Based on the length of the visual extension caused by the dynamic blur effect of the marker, the rotation speed of the rotating object is calculated. The present invention uses the method of marker recognition to monitor the rotation speed of the rotating object in real time, and through optimizing the combination of software and hardware, accurate measurement of the rotation speed is achieved. The present invention does not require a sensor to be set on the rotating object, but determines the rotation speed of the rotating object through a camera shooting method, avoiding contact with the rotating object and the influence of factors such as strong vibration and electromagnetic interference. At the same time, since only a marker is set on the rotating object, there is no need to supply power and lay wires for the marker, and there is no need to change the rotating object, so it has a better application space. Even when it is necessary to change the installation method of the device, the position of the marker can be easily replaced and adjusted.
[0133] In one embodiment, the rotation parameter is the pixel length of the rotation radius of the rotation axis, the marker parameter is the pixel length of the marker of the marker, the camera parameter is the number of frames of the camera device, and calculating the rotation speed of the rotating object according to the visual extension length, the rotation parameter, the marker parameter, and the camera parameter includes:
[0134] Calculating the rotation speed of the rotating object according to the visual extension length, the pixel length of the rotation radius, the pixel length of the marker, and the number of frames.
[0135] In one embodiment, the rotation speed is the angular velocity, and calculating the rotation speed of the rotating object according to the visual extension length, the pixel length of the rotation radius, the pixel length of the marker, and the number of frames includes:
[0136] Calculating the angular velocity of the rotating object as where f is the number of frames, L is the visual extension length, d is the pixel length of the marker, and R is the pixel length of the rotation radius.
[0137] In one embodiment, obtaining the rotation parameter of the rotating object and / or the marker parameter of the marker moving on the surface of the rotating object with the rotating object includes:
[0138] Obtaining a photo of the rotating object taken by the camera device when the rotating object is stationary, and extracting the pixel length of the rotation radius of the rotation radius and / or the pixel length of the marker of the marker from the photo.
[0139] In one embodiment, the rotation parameter is the rotation radius of the rotation axis, the marker parameter is the physical length of the marker, the imaging parameter is the number of frames of the imaging device, and calculating the rotation speed of the rotating object according to the visually extended length, the rotation parameter, the marker parameter, and the imaging parameter includes:
[0140] Obtain the rotation radius pixel length of the rotation radius and / or the marker pixel length of the marker;
[0141] Use the ratio of the rotation radius to the rotation radius pixel length as the magnification factor, or use the ratio of the physical length of the marker to the marker pixel length as the magnification factor;
[0142] Multiply the visually extended length by the magnification factor to obtain the actual visually extended length;
[0143] Calculate the rotation speed of the rotating object according to the actual visually extended length, the rotation radius, the physical length of the marker, and the number of frames.
[0144] In one embodiment, the rotation speed is the angular velocity, and calculating the rotation speed of the rotating object according to the actual visually extended length, the rotation radius, the physical length of the marker, and the number of frames includes:
[0145] Calculate the angular velocity of the rotating object as where f is the number of frames, L1 is the actual visually extended length, d1 is the physical length of the marker, and R1 is the rotation radius.
[0146] In one embodiment, the marker is a coating, a sticker, a marking point, or a texture.
[0147] Regarding the device in the above embodiments, the specific manners in which each module performs operations have been described in detail in the embodiments related to the method, and will not be elaborated herein.
[0148] As Figure 11 shown is a schematic hardware structure diagram of an electronic device according to the present invention, including:
[0149] At least one processor 1101; and,
[0150] A memory 1102 communicatively connected to at least one of the processors 1101; wherein,
[0151] The memory 1102 stores instructions that can be executed by at least one of the processors. The instructions are executed by at least one of the processors so that at least one of the processors can execute the rotational speed detection method described above.
[0152] Figure 11 Take one processor 1101 as an example.
[0153] The electronic device may further include: an input device 1103 and a display device 1104.
[0154] The processor 1101, the memory 1102, the input device 1103, and the display device 1104 may be connected by a bus or other means. In the figure, connection by a bus is taken as an example.
[0155] As a non-volatile computer-readable storage medium, the memory 1102 can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as the program instructions / modules corresponding to the rotational speed detection method in the embodiments of the present application. For example, Figure 1 , Figure 2 The method flow shown. By running the non-volatile software programs, instructions, and modules stored in the memory 1102, the processor 1101 executes various functional applications and data processing, that is, implements the rotational speed detection method in the above embodiments.
[0156] The memory 1102 may include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created according to the use of the rotational speed detection method, etc. In addition, the memory 1102 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage devices. In some embodiments, the memory 1102 may optionally include a memory remotely provided with respect to the processor 1101, and these remote memories can be connected to the device for executing the rotational speed detection method through a network. Examples of the above network include but are not limited to the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.
[0157] The input device 1103 can receive input user clicks and generate signal inputs related to user settings and function controls of the rotational speed detection method. The display device 1104 may include a display device such as a display screen.
[0158] When the one or more modules are stored in the memory 1102 and run by the one or more processors 1101, they execute the rotational speed detection method in any of the above method embodiments.
[0159] The present invention calculates the rotational speed of a rotating object by setting markers on the rotating object, shooting a video of the markers rotating with the rotating object, and based on the length of the visual extension caused by the dynamic blur effect of the markers. The present invention uses the method of marker recognition to monitor the rotational speed of the rotating object in real time, and realizes accurate measurement of the rotational speed by optimizing the combination of software and hardware. The present invention does not require setting sensors on the rotating object, but determines the rotational speed of the rotating object through the camera shooting method, avoiding contact with the rotating object and the influence of factors such as strong vibration and electromagnetic interference. At the same time, since only markers are set on the rotating object, there is no need to supply power and route wires for the markers, and there is no need to change the rotating object, enabling it to have a better application space. Even when it is necessary to change the installation method of the device, it is also possible to easily replace and adjust the position of the markers.
[0160] An embodiment of the present invention provides a storage medium that stores computer instructions, which are used to execute all steps of the rotational speed detection method as described above when the computer executes the computer instructions.
[0161] The above embodiments only represent several implementation manners of the present invention, and the description thereof is relatively specific and detailed, but it should not be understood as a limitation to the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.
Claims
1. A rotational speed detection method, characterized in that, it includes: Obtaining the rotation parameters of the rotating object and / or the marker parameters of the marker moving with the rotating object on the surface of the rotating object, and obtaining the imaging parameters of the imaging device for photographing the marker; Obtaining the video of the marker rotating with the rotating object by the imaging device, and extracting key frames from the video; Obtaining the visual extension length of the marker in the key frame, where the visual extension length is the length of the visual extension caused by the dynamic blur effect of the marker; Calculating the rotational speed of the rotating object according to the visual extension length, the rotation parameters, the marker parameters, and the imaging parameters.
2. The rotational speed detection method according to claim 1, characterized in that, the rotation parameter is the pixel length of the rotation radius of the rotation axis, the marker parameter is the pixel length of the marker, the imaging parameter is the number of frames of the imaging device, and calculating the rotational speed of the rotating object according to the visual extension length, the rotation parameters, the marker parameters, and the imaging parameters includes: Calculating the rotational speed of the rotating object according to the visual extension length, the pixel length of the rotation radius, the pixel length of the marker, and the number of frames.
3. The rotational speed detection method according to claim 2, characterized in that, the rotational speed is the angular velocity, and calculating the rotational speed of the rotating object according to the visual extension length, the pixel length of the rotation radius, the pixel length of the marker, and the number of frames includes: Calculate the angular velocity of the rotating object as where f is the number of frames, L is the visual extension length, d is the pixel length of the marker, and R is the pixel length of the rotation radius.
4. The rotational speed detection method according to claim 2, characterized in that, obtaining the rotation parameters of the rotating object and / or the marker parameters of the marker moving with the rotating object on the surface of the rotating object includes: Obtaining the photo of the rotating object when it is stationary by the imaging device, and extracting the pixel length of the rotation radius of the rotation radius and / or the pixel length of the marker from the photo.
5. The rotational speed detection method according to claim 1, characterized in that, the rotation parameter is the rotation radius of the rotation axis, the marker parameter is the physical length of the marker, the imaging parameter is the number of frames of the imaging device, and calculating the rotational speed of the rotating object according to the visual extension length, the rotation parameters, the marker parameters, and the imaging parameters includes: Obtaining the pixel length of the rotation radius of the rotation radius and / or the pixel length of the marker; Taking the ratio of the rotation radius to the pixel length of the rotation radius as the magnification factor, or taking the ratio of the physical length of the marker to the pixel length of the marker as the magnification factor; Multiplying the visual extension length by the magnification factor to obtain the actual visual extension length; Calculating the rotational speed of the rotating object according to the actual visual extension length, the rotation radius, the physical length of the marker, and the number of frames.
6. The rotational speed detection method according to claim 5, characterized in that, The rotation speed is the angular velocity. Calculating the rotation speed of the rotating object according to the actual length of the visual extension, the rotation radius, the physical length of the marker of the marker, and the number of frames includes: Calculate the angular velocity of the rotating object as where f is the number of frames, L1 is the actual length of the visual extension, d1 is the physical length of the marker of the marker, and R1 is the rotation radius.
7. The rotation speed detection method according to any one of claims 1 to 6, characterized in that the marker is a coating, a sticker, a marker point or a texture.
8. A rotation speed detection device, characterized in that it includes: a parameter acquisition module, configured to acquire the rotation parameters of the rotating object and / or the marker parameters of the marker moving on the surface of the rotating object along with the rotating object, and acquire the imaging parameters of the imaging device that captures the marker; a key frame acquisition module, configured to acquire the video of the marker captured by the imaging device as the rotating object rotates, and extract key frames from the video; a visual extension length acquisition module, configured to acquire the visual extension length of the marker in the key frame, where the visual extension length is the length of the visual extension caused by the dynamic blur effect of the marker; a rotation speed calculation module, configured to calculate the rotation speed of the rotating object according to the visual extension length, the rotation parameters, the marker parameters, and the imaging parameters.
9. An electronic device, characterized in that it includes: at least one processor; and, a memory communicatively connected to at least one of the processors; wherein, the memory stores instructions executable by at least one of the processors, and the instructions are executed by at least one of the processors so that at least one of the processors can execute the rotation speed detection method according to any one of claims 1 to 7.
10. A storage medium, characterized in that the storage medium stores computer instructions, and when the computer executes the computer instructions, it is used to execute all steps of the rotation speed detection method according to any one of claims 1 to 7.