A time difference determination method and system, and a waveform processing module

Abstract

The embodiments of the present invention provide a time difference measurement method and system, and a waveform processing module, which relate to the field of time measurement technology. The time difference measurement method includes: after the image acquisition device is started, a test trigger signal is sent to the image acquisition device, and the test image acquired by the image acquisition device and the test trigger signal are acquired; based on the image output time of the target test image in the test image and the trigger time of the target test trigger signal in the test trigger signal, the trigger output time difference of the image acquisition device is obtained, wherein each of the target test images is acquired by the image acquisition device under the control of a corresponding target test trigger signal. The present invention is capable of measuring the trigger output time difference of the image acquisition device.

Description

Technical Field

[0001] The present invention relates to the field of measurement technology, and in particular to a time difference measurement method and system, and a waveform processing module. Background Art

[0002] In a vehicle equipped with a camera, the camera can capture images under the trigger of a trigger signal, and the captured frames can form a video. The captured video can be used for playback, or can be injected back into the controller to verify or train the controller's algorithm, or can be used to fuse with other data (such as point cloud data collected by radar) to meet the needs of subsequent analysis and processing.

[0003] In the prior art, for image acquisition devices, the time difference between triggering a trigger signal and outputting an image is often unknown, and this time difference is often different for different image acquisition devices. This will lead to a lack of corresponding information as a reference for subsequent analysis and processing of the image. Summary of the invention

[0004] The purpose of the present invention is to provide a time difference measurement method and system, and a waveform processing module, which can measure the triggering time difference of an image acquisition device. The triggering time difference can be used to determine the accurate triggering time of each image data signal acquired by the image acquisition device during the use of the image acquisition device, so as to facilitate subsequent processing, such as playing back, fusion, and re-annotation of the image data.

[0005] To achieve the above-mentioned purpose, the present invention provides a time difference measurement method, comprising: after an image acquisition device is started, sending a test trigger signal to the image acquisition device, and acquiring a test image acquired by the image acquisition device and the test trigger signal; based on the output time of a target test image in the test image and the trigger time of a target test trigger signal in the test trigger signal, obtaining the trigger output time difference of the image acquisition device, wherein each of the target test images is acquired by the image acquisition device under the control of a corresponding target test trigger signal.

[0006] The present invention also provides a waveform processing module for executing the above-mentioned time difference determination method.

[0007] The present invention also provides a time difference measurement system, comprising: the above-mentioned waveform processing module, and a signal generator communicatively connected to the waveform processing module, wherein the waveform processing module and the signal generator are both communicatively connected to an image acquisition device; the image acquisition device is used to acquire a test image after startup, and send the acquired image to the waveform processing module; the signal generator is used to generate a test trigger signal, and send the test trigger signal to the image acquisition device and the waveform processing module respectively.

[0008] In one embodiment, the test trigger signal includes a first test trigger signal, and the test image includes a first test image and a second test image; sending the test trigger signal to the image acquisition device, and acquiring the test image and the test trigger signal acquired by the image acquisition device, includes: based on the reference time interval of the second test image sent by the image acquisition device, determining a target time interval different from the reference time interval as the time interval of the first test trigger signal; sending the first test trigger signal to the image acquisition device, and acquiring the first test image and the first test trigger signal acquired by the image acquisition device; before obtaining the trigger output time difference of the image acquisition device based on the output time of the target test image in the test image and the trigger time of the target test trigger signal in the test trigger signal, it also includes: selecting one or more of the first test images with a time interval of the target time interval from the acquired first test images as the target test images, and selecting the target test trigger signal in the first test trigger signal.

[0009] In one embodiment, before determining a target time interval different from the reference time interval of the second test image emitted by the image acquisition device as the time interval of the first test trigger signal, the method further includes: determining that the image acquisition device emits the second test image after startup.

[0010] In one embodiment, before determining a target time interval different from the reference time interval as the time interval of the first test trigger signal based on the reference time interval of the second test image emitted by the image acquisition device, the method further includes: determining that the second test image has not been emitted by the image acquisition device after startup; emitting a set number of second test trigger signals to the image acquisition device based on a preset time interval, and acquiring the second test image and the second test trigger signal emitted by the image acquisition device; and determining that the image acquisition device has generated additional image output, wherein the additional image output indicates that a test image emitted by the image acquisition device is acquired after the preset duration of stopping the emission of the second test trigger signal to the image acquisition device.

[0011] In one embodiment, the test image includes a third test image, and the test trigger signal includes a third test trigger signal; sending the test trigger signal to the image acquisition device, and acquiring the test image and the test trigger signal acquired by the image acquisition device, includes: sending a specified number of the third test trigger signals to the image acquisition device based on a preset time interval; acquiring the third test image and the third test trigger signal issued by the image acquisition device after receiving the third test trigger signal; before obtaining the trigger output time difference of the image acquisition device based on the output time of the target test image in the test image and the trigger time of the target test trigger signal in the test trigger signal, it also includes: selecting the target test image from the acquired third test image, and selecting the target test trigger signal in the third test trigger signal.

[0012] In one embodiment, before selecting the target test image from the acquired third test image and selecting the target test trigger signal from the third test trigger signal, it also includes: determining that no additional image output occurs from the image acquisition device; the additional image output indicates that after stopping sending the third test trigger signal to the image acquisition device for a preset period of time, a test image sent by the image acquisition device is acquired.

[0013] In one embodiment, the target test image is the last N test images acquired, and the target test trigger signal is the last N test trigger signals acquired, where N is an integer greater than or equal to 1.

[0014] In one embodiment, the triggering time difference of the image acquisition device is obtained based on the image output time of the target test image in the test image and the triggering time of the target test trigger signal in the test trigger signal, including: if the number of the target test image is one, then the absolute value of the difference between the image output time of the target test image and the triggering time of the corresponding target test trigger signal is used as the triggering time difference of the image acquisition device; if the number of the target test images is multiple, then the absolute value of the difference between the image output time of each target test image and the triggering time of the corresponding target test trigger signal is obtained to obtain multiple reference time differences, and the triggering time difference of the image acquisition device is obtained based on the multiple reference time differences. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a waveform diagram of the existing trigger signal input to the camera and the image signal output by the camera, wherein the first two images of the camera are not output according to the time interval of the trigger signal;

[0016] Figure 2 It is a waveform diagram of the existing trigger signal input to the camera and the image signal output by the camera, wherein the camera starts to continuously collect images when no trigger signal is received after power-on;

[0017] Figure 3 is a block diagram of a time difference measurement system for implementing the above-mentioned time difference measurement method according to a first embodiment of the present invention;

[0018] Figure 4 is a block diagram of a time difference measurement system for implementing the above-mentioned time difference measurement method according to a first embodiment of the present invention, wherein the time difference measurement system further includes a signal processing module;

[0019] Figure 5 is a specific flow chart of the trigger time determination method according to the first embodiment of the present invention;

[0020] Figure 6 is a specific flow chart of the trigger time determination method according to the second embodiment of the present invention;

[0021] Figure 7 is a specific flow chart of the trigger time determination method in the second embodiment of the present invention. DETAILED DESCRIPTION

[0022] The following will be described in detail with reference to the accompanying drawings to provide a clearer understanding of the purpose, features and advantages of the present invention. It should be understood that the embodiments shown in the accompanying drawings are not intended to limit the scope of the present invention, but are only intended to illustrate the essential spirit of the technical solution of the present invention.

[0023] In the following description, certain specific details are set forth for the purpose of illustrating various disclosed embodiments to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the relevant art will recognize that the embodiments may be practiced without one or more of these specific details. In other cases, well-known devices, structures, and techniques associated with the present application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

[0024] Unless the context requires otherwise, throughout the specification and claims, the word "comprise" and variations such as "include" and "have" should be construed in an open, inclusive sense, ie, should be interpreted as "including, but not limited to."

[0025] References throughout the specification to "one embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of "in one embodiment" or "in an embodiment" in various places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any manner in one or more embodiments.

[0026] As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally employed in its sense including "or / and" unless the context clearly dictates otherwise.

[0027] In the following description, in order to clearly show the structure and working mode of the present invention, many directional words will be used for description, but the words "front", "back", "left", "right", "outside", "inside", "outward", "inward", "up", "down", etc. should be understood as convenient terms and should not be understood as restrictive terms.

[0028] For a camera, it should collect signals in response to each received trigger signal to obtain an image. The trigger signal corresponds to the image one by one, so the trigger signal and the image can be sorted separately, and the trigger signal corresponding to each image can be obtained based on the information representing the sequence (such as the serial number). However, due to some characteristics of the camera itself, there will be problems with the camera output, and it is impossible to accurately obtain the one-to-one correspondence between the trigger signal and the image, such as the following situations:

[0029] Case 1: Even if the camera receives a trigger signal, it cannot accurately capture images within a period of time after it is powered on. For example, the camera does not capture images after receiving a trigger signal; or, for another example, the camera receives a trigger signal but does not capture images at the time interval of the trigger signal. The camera is also uncertain and unfixed when it receives a trigger signal to accurately capture images. Please refer to Figure 1 , which is the waveform diagram of the trigger signal input to the camera and the image signal output by the camera. Figure 1 In the figure, 8 trigger signals with the same time interval are input to the camera, but in the 8 images output by the camera, the time interval between the output of the first two images is different from the time interval of the trigger signals, that is, the first two images of the camera are not output according to the time interval of the trigger signals.

[0030] In case 2, the camera will automatically or after receiving the first trigger signal, automatically collect images for a certain period of time at a certain frequency and cycle. During this period of time, the camera will collect images even if it does not receive a trigger signal. Please refer to Figure 2 , which is the waveform diagram of the trigger signal input to the camera and the image signal output by the camera. Figure 2 After the camera is powered on, it starts to continuously acquire images when no trigger signal is received, and it is still in the process of continuous image acquisition after receiving the first trigger signal.

[0031] Of course, after power-on, during the normal acquisition process, abnormal situations may occur due to the communication environment, software or hardware failures, etc. For example, the camera is triggered but no image is displayed, or an image is displayed without a trigger signal.

[0032] Based on the above two situations, it is impossible to simply find out the trigger signal corresponding to each image captured by the camera based on the sorting results. Based on this, the trigger output time difference of the camera (that is, the time difference between the trigger time of the trigger signal and the output time of the corresponding image) can be measured in advance, and the trigger output time difference of the camera can be used to find out the trigger signal corresponding to each image captured by the camera, that is, the accurate trigger time of each image can be obtained, which is used for subsequent playback, fusion, re-annotation and other processing of the image data. Based on the above problems, the applicant proposed the time difference measurement method of the present application.

[0033] The first embodiment of the present invention relates to a time difference determination method, which is applied to a waveform processing module, and the waveform processing module can determine the triggering time difference of an image acquisition device (such as a camera) based on the time difference determination method. The waveform processing module can be a processor, a controller, etc.

[0034] Please refer to Figure 3 The time difference measurement system for implementing the above-mentioned time difference measurement method includes: a waveform processing module 1 and a signal generator 2 that are communicatively connected, and the waveform processing module 1 and the signal generator 2 are both communicatively connected to an image acquisition device 3; wherein the signal generator 2 is used to generate a trigger signal according to a configured frequency and period, and the time interval between two adjacent trigger signals remains unchanged, which can be configured manually or by the waveform processing module 1.

[0035] In another example, see Figure 4 The time difference measurement system further includes: a signal processing module 4, through which the image acquisition device 3 is connected to the waveform processing module 1 for communication. At this time, the signal processing module 4 can be used to perform initial parameter configuration on the image acquisition device 3, including but not limited to: the configuration of parameters such as acquisition frame rate and image resolution; during the measurement process, the signal processing module 4 can also transmit the image data of the image acquired by the image acquisition device 3 to the waveform processing module 1. It should be noted that in this embodiment and the following embodiments, Figure 3 The time difference measurement system is used as an example to illustrate.

[0036] The specific process of the time difference measurement method in this embodiment is as follows: Figure 5 shown.

[0037] Step 101: after the image acquisition device is started, a test trigger signal is sent to the image acquisition device, and a test image and a test trigger signal acquired by the image acquisition device are obtained.

[0038] Specifically, when measuring the triggering time difference of the image acquisition device, the image acquisition device is first powered on and started, the waveform processing module controls the signal generator to generate a test trigger signal, and sends the test trigger signal to the image acquisition device, and the image acquisition device sends the acquired test image to the waveform processing module, wherein the image acquired by the image acquisition device, in addition to the test image acquired under the control of the test trigger signal, may also include one or more additional images acquired without triggering the image acquisition device, that is, the aforementioned situation 2 occurs, and the image acquisition device automatically acquires one or more additional images within a period of time after power-on or after receiving the first test trigger signal.

[0039] From the above, the waveform processing module can obtain the test image captured by the image acquisition device and the test trigger signal generated by the signal generator.

[0040] Step 102, based on the output time of the target test image in the test image and the trigger time of the target test trigger signal in the test trigger signal, obtain the trigger output time difference of the image acquisition device, wherein each target test image is acquired by the image acquisition device controlled by a corresponding target test trigger signal.

[0041] Specifically, the waveform processing module has selected at least one target test image from the acquired test images and selected a target test trigger signal corresponding to each target test image from the acquired test trigger signal. The target test image is acquired by the image processing device under the control of the test trigger signal, that is, each target test image is an image acquired by the image acquisition device under the control of the corresponding target test trigger signal.

[0042] In one example, the target test image is the last N test images acquired, and the target test trigger signal is the last N test trigger signals acquired, where N is an integer greater than or equal to 1. That is, the waveform processing module sorts the test images in the order of acquisition, and after completing the acquisition of the test images, selects the last N test images received as the target test images, and these N target test images are acquired by the image processing device under the control of the test trigger signal; similarly, the waveform processing module sorts the test trigger signals in the order of acquisition, selects the last N test trigger signals received as the target test trigger signals, and the N target test images are acquired under the control of the N target test trigger signals, and the N target test images can be matched one by one with the N target test trigger signals in the order from back to front, thereby acquiring the target test trigger signals corresponding to each target test image. By selecting the last N test images and test signals, it can help avoid: the image and trigger signal cannot accurately correspond based on the sequence due to abnormal conditions after power-on.

[0043] If the number of selected target test images is one, the time difference between the output time of the target test image and the trigger time of the corresponding target test trigger signal is directly calculated, and the time difference is the trigger output time difference of the image acquisition device.

[0044] If there are multiple target test images selected, first obtain the absolute value of the difference between the image output time of each target test image and the trigger time of the corresponding target test trigger signal to obtain multiple reference time differences, that is, for each target test image and its corresponding target test trigger signal, calculate a time difference value, which is recorded as the reference time difference, thereby obtaining multiple reference time differences; then, based on the multiple reference time differences, obtain the triggering time difference of the image acquisition device, for example, by selecting the median or calculating the average, and using multiple reference time differences to obtain the triggering time difference of the image acquisition device.

[0045] The output time of the target test image can be read from the waveform of the received image data signal. Similarly, the triggering time of the target test trigger signal can also be read from the waveform of the received trigger signal.

[0046] It should be noted that in this embodiment, the test image and test trigger signal received by the waveform processing module can also be displayed in an oscilloscope, and the target test image and target test trigger signal are manually selected and input into the waveform processing module, and then the waveform processing module completes the above-mentioned trigger output time difference acquisition process.

[0047] In this embodiment, when determining the triggering image output time difference of the image acquisition device, the image acquisition device is first started, a test trigger signal is sent to the image acquisition device, and the test image and the test trigger signal acquired by the image acquisition device are obtained, and the target test image acquired by the image acquisition device controlled by the target test trigger signal in the test image is obtained, and then the triggering image output time difference of the image acquisition device is obtained by combining the image output time of the target test image and the triggering time of the target test trigger signal; the triggering image output time difference can be used to determine the accurate triggering time of the image acquired by the image acquisition device during the use of the image acquisition device, so as to facilitate subsequent processing, such as playing back, fusion, and re-annotation of the image data.

[0048] The second embodiment of the present invention relates to a time difference measurement method. The main difference between this embodiment and the first embodiment is that this embodiment provides a process for distinguishing between the above-mentioned situations 1 and 2 and realizing time difference measurement.

[0049] The specific process of the time difference measurement method of this embodiment is as follows Figure 6 In this embodiment, the test trigger signal includes a first test trigger signal and a second test trigger signal, and the test image includes a first test image and a second test image.

[0050] Step 201 includes the following sub-steps:

[0051] Sub-step 2011, determining whether the image acquisition device sends out a second test image after startup. If not, proceed to step 2012; if yes, proceed to step 2014.

[0052] Sub-step 2012: sending a set number of second test trigger signals to the image acquisition device based on a preset time interval, and acquiring a second test image and a second test trigger signal sent by the image acquisition device.

[0053] Sub-step 2013, determining whether the image acquisition device has additional image output, where additional image output means that after stopping the preset time of sending the second test trigger signal to the image acquisition device, a test image sent by the image acquisition device is obtained. If yes, proceed to step 2014; if no, proceed to step 203.

[0054] Sub-step 2014, based on the reference time interval of the second test image sent by the image acquisition device, determining a target time interval different from the reference time interval as the time interval of the first test trigger signal.

[0055] Sub-step 2015: sending a first test trigger signal to the image acquisition device, and acquiring a first test image and a first test trigger signal acquired by the image acquisition device.

[0056] Step 202 : Select one or more first test images with a time interval of a target time interval from the acquired first test images as target test images, and select a target test trigger signal from the first test trigger signals.

[0057] Specifically, after the image acquisition device is powered on, the image acquisition device may be configured first. For example, the waveform processing module configures the image acquisition device through the signal processing module. After the image acquisition device is configured, before the waveform processing module sends a test trigger signal to the image acquisition device through the signal generator:

[0058] If the waveform processing module receives the second test image, that is, it is determined that the image acquisition device sends the second test image after startup, it means that the image acquisition device has the aforementioned situation 2, and the image acquisition device automatically performs image acquisition after startup, and sends the acquired image to the waveform processing module; at this time, the waveform processing module first obtains the time interval between any two adjacent second test images as the reference time interval p, and determines a target time interval q different from the reference time interval p, and the target time interval q can be greater than or less than the reference time interval p. The waveform processing module then uses the determined target time interval q as the time interval of the first test trigger signal to be sent to the image acquisition device, and controls the signal generator to send the first test trigger signal to the image acquisition device according to the target time interval q. When the image acquisition device outputs the image according to the target time interval q, it is determined that the image acquisition device is controlled by the first test trigger signal. Among them, the time interval for the signal generator to send the first test trigger signal can be achieved by setting the frequency, cycle, etc. of the trigger signal sent by the signal generator.

[0059] The waveform processing module obtains the first test image acquired by the image acquisition device and the first test trigger signal emitted by the signal generator, and then enters step 202, selects one or more first test images with a time interval of the target time interval q from the acquired first test images as target test images, and selects the target test trigger signal from the first test trigger signal, and then enters step 203 to obtain the trigger output time difference of the image acquisition device based on the output time of the target test image in the test image and the trigger time of the target test trigger signal in the test trigger signal.

[0060] If the waveform processing module does not receive the second test image, the control signal generator sends a set number of second test trigger signals to the image acquisition device according to the preset time interval, where the set number can be preset in the waveform processing module, the preset time interval can be preset in the waveform processing module or the signal generator, and the time interval for the signal generator to send the second test trigger signal can be achieved by setting the frequency, period, etc. of the trigger signal sent by the signal generator.

[0061] The waveform processing module obtains the second test image collected by the image acquisition device and the second test trigger signal sent by the signal generator, and then determines whether the image acquisition device has an additional image output. The additional image output means that after the preset time length of stopping sending the second test trigger signal to the image acquisition device, a test image sent by the image acquisition device is obtained. For example, after the signal generator sends a set number of second test trigger signals, the timing starts. If the second test image sent by the image acquisition device can still be received after the timing reaches the preset time length, when it is determined that the image acquisition device has an additional image output, it means that after receiving the second test trigger signal, the image acquisition device first performs automatic image acquisition for a certain period of time, and then performs image acquisition according to the second test trigger signal, that is, the image acquisition device has the aforementioned situation 2; at this time, there are two time intervals between two adjacent second test images in the multiple second test images obtained by the waveform processing module, one is the preset time interval of the second trigger signal, and the other is the preset time interval of the image acquisition device. A reference time interval k for automatically capturing images (the reference time interval k may be equal to or different from the aforementioned reference time interval p), and then the waveform processing module determines a target time interval l that is different from the reference time interval k, and the target time interval l may be greater than or less than the reference time interval k. The waveform processing module then uses the determined target time interval l as the time interval of the first test trigger signal to be sent to the image acquisition device, and controls the signal generator to send the first test trigger signal to the image acquisition device according to the target time interval l, and determines that the image acquisition device is controlled by the first test trigger signal when the image acquisition device outputs the image according to the target time interval l. The time interval for the signal generator to send the first test trigger signal can be achieved by setting the frequency, cycle, etc. of the trigger signal sent by the signal generator.

[0062] The waveform processing module acquires the first test image acquired by the image acquisition device and the first test trigger signal emitted by the signal generator, and then enters step 202, selects one or more first test images with a time interval of the target time interval from the acquired first test images as target test images, and selects the target test trigger signal from the first test trigger signal, and then enters step 203 to obtain the trigger output time difference of the image acquisition device based on the output time of the target test image in the test image and the trigger time of the target test trigger signal in the test trigger signal.

[0063] When it is determined that the image acquisition device has not produced additional images, it may be that situation 1 has occurred or not; at this time, one or more second test images with a time interval of a preset time interval can be selected from the acquired second test images as target test images, and the second test images with a time interval of a preset time interval can be considered to be acquired by the image acquisition device under the control of the second test trigger signal, and the target test trigger signal is selected from the second test trigger signal; or the selected target test images are the last N second test images acquired, and the selected target test trigger signal is the last N second test trigger signals acquired; N is an integer greater than or equal to 1. Then proceed to step 203 to obtain the triggering time difference of the image acquisition device based on the output time of the target test image in the test image and the triggering time of the target test trigger signal in the test trigger signal.

[0064] Step 203, based on the output time of the target test image in the test image and the trigger time of the target test trigger signal in the test trigger signal, obtain the trigger output time difference of the image acquisition device, wherein each target test image is acquired by the image acquisition device controlled by a corresponding target test trigger signal. It is substantially the same as step 102 in the first embodiment and will not be repeated here.

[0065] This embodiment can address the above-mentioned situation 2 occurring in the image acquisition device by constructing a target time interval different from the image output interval of the image acquisition device in situation 2, and then sending a test trigger signal to the image acquisition device at the target time interval. When the image acquisition device outputs images at the target time interval, it is determined that the image acquisition device is controlled by the test trigger signal, thereby obtaining a trigger output time difference that meets the characteristics of each image acquisition device, which is more accurate.

[0066] The third embodiment of the present invention relates to a time difference measurement method. The main difference between this embodiment and the first embodiment is that the triggering time difference can be directly obtained based on the received test image and the test trigger signal.

[0067] The specific process of the time difference measurement method of this embodiment is as follows Figure 7 In this embodiment, the test image includes a third test image, and the test trigger signal includes a third test trigger signal.

[0068] Step 301 includes the following sub-steps:

[0069] Sub-step 3011: sending a specified number of third test trigger signals to the image acquisition device based on a preset time interval.

[0070] Sub-step 3012, acquiring a third test image and a third test trigger signal sent by the image acquisition device after receiving the third test trigger signal.

[0071] In one example, after step 301, the method further includes:

[0072] Step 302, determine whether the image acquisition device has additional image output, which means that after the preset time period of stopping sending the second test trigger signal to the image acquisition device, a test image sent by the image acquisition device is obtained. If yes, then end directly; if not, proceed to step 303.

[0073] Step 303: Select a target test image from the acquired third test image, and select a target test trigger signal from the third test trigger signal.

[0074] Specifically, the waveform processing module controls the signal generator to send a specified number of third test trigger signals to the image acquisition device according to the preset time interval, wherein the specified number can be preset in the waveform processing module, the preset time interval can be preset in the waveform processing module or the signal generator, and the time interval for the signal generator to send the second test trigger signal can be achieved by setting the frequency, period, etc. of the trigger signal sent by the signal generator.

[0075] In one example, the specified number of third test trigger signals can be a sufficient number of third test trigger signals, so that even if the image acquisition device has the above-mentioned situation 1 and / or situation 2, since the number of third test trigger signals is sufficient, it can be ensured that the last one or more third test images acquired by the image acquisition device are acquired under the control of the third test trigger signal; at this time, step 302 can be skipped directly and step 303 can be entered directly to select the last N third test images from the multiple third test images as the target test images, and select the last N third test trigger signals acquired from the multiple third trigger signals acquired as the target test trigger signals; N is an integer greater than or equal to 1.

[0076] In another example, the number of the specified number of third test trigger signals is small, and it cannot be guaranteed that when the image acquisition device is in the above-mentioned situation 1 and / or situation 2, the last one or more third test images acquired by the image acquisition device are acquired under the control of the third test trigger signal; thus, step 303 is entered to determine whether the image acquisition device has additional image output, and the additional image output means that: after the preset length of time of stopping sending the third test trigger signal to the image acquisition device, the test image sent by the image acquisition device is obtained. For example, after the signal generator sends a set number of third test trigger signals, timing starts. If the third test image sent by the image acquisition device can still be received after timing up to the preset time length, it is determined that the image acquisition device has output additional images; if the third test image is no longer received after timing up to the preset time length, it is determined that the image acquisition device has not output additional images, wherein the preset time length may be greater than one times the preset time interval and less than two times the preset time interval; or, the waveform processing module compares the number of third test images obtained with the number of third test trigger signals. If the number of third test images is greater than the number of third test trigger signals, it is determined that the image acquisition device has output additional images; if the number of third test images is equal to the number of third test trigger signals, it is determined that the image acquisition device has not output additional images.

[0077] When it is determined that the image acquisition device has not produced additional images, one or more third test images with a time interval of a preset time interval are selected from the acquired third test images as target test images. The third test images with a time interval of the preset time interval can be considered to be acquired by the image acquisition device controlled by the third test trigger signal, and the target test trigger signal is selected from the third test trigger signal; or the selected target test image is the last N third test images acquired, and the selected target test trigger signal is the last N third test trigger signals acquired; N is an integer greater than or equal to 1.

[0078] In addition, when it is determined that the image acquisition device has output additional images, it means that after receiving the second test trigger signal, the image acquisition device first performs automatic image acquisition for a certain period of time, and then performs image acquisition according to the second test trigger signal, that is, the image acquisition device has the aforementioned situation 2. At this time, the specific processing method for situation 2 in the second embodiment can be referred to, and it will not be repeated here.

[0079] Step 304, based on the output time of the target test image in the test image and the trigger time of the target test trigger signal in the test trigger signal, obtain the trigger output time difference of the image acquisition device, wherein each target test image is acquired by the image acquisition device controlled by a corresponding target test trigger signal. It is substantially the same as step 102 in the first embodiment and will not be repeated here.

[0080] In this embodiment, the triggering time difference of the image acquisition device is directly obtained based on the received test image and the test trigger signal, which can be adapted to both situation 1 and situation 2, and helps to obtain the triggering time difference of the image acquisition device more conveniently and quickly.

[0081] The fourth embodiment of the present invention relates to a waveform processing module, which is used to execute the time difference measurement method of any one of the first to third embodiments, wherein the waveform processing module can be a processor, a controller, etc.

[0082] Since the first to third embodiments correspond to this embodiment, this embodiment can be implemented in conjunction with the first to third embodiments. The relevant technical details mentioned in the first to third embodiments are still valid in this embodiment, and the technical effects that can be achieved in the first to third embodiments can also be achieved in this embodiment. In order to reduce repetition, they are not repeated here. Accordingly, the relevant technical details mentioned in this embodiment can also be applied to the first to third embodiments.

[0083] The fifth embodiment of the present invention relates to a time difference measurement system. Figure 3 The time difference measurement system includes: a waveform processing module 1 and a signal generator 2 which are communicatively connected, and the waveform processing module 1 and the signal generator 2 are both communicatively connected to an image acquisition device 3; wherein the signal generator 2 is used to generate a trigger signal according to a configured frequency and period, and the time interval between two adjacent trigger signals remains unchanged, which can be configured manually or by the waveform processing module 1.

[0084] In another example, see Figure 4 The time difference measurement system also includes: a signal processing module 4, the image acquisition device 3 is communicated with the waveform processing module 1 through the signal processing module 4, and the signal processing module 4 can be used to perform initial parameter configuration on the image acquisition device 3, including but not limited to: configuration of parameters such as acquisition frame rate and image resolution; during the measurement process, the signal processing module 4 can also transmit the image data of the image acquired by the image acquisition device 3 to the waveform processing module 1.

[0085] The image acquisition device 3 is used to acquire test images after startup and send the acquired images to the waveform processing module 1 .

[0086] The signal generator 2 is used to generate a test trigger signal, and send the test trigger signal to the image acquisition device and the waveform processing module 1 respectively.

[0087] The waveform processing module 1 is the waveform processing module in the fourth embodiment, that is, used to execute any one of the time difference measuring methods in the first embodiment to the third embodiment.

[0088] Since the first to third embodiments correspond to this embodiment, this embodiment can be implemented in conjunction with the first to third embodiments. The relevant technical details mentioned in the first to third embodiments are still valid in this embodiment, and the technical effects that can be achieved in the first to third embodiments can also be achieved in this embodiment. In order to reduce repetition, they are not repeated here. Accordingly, the relevant technical details mentioned in this embodiment can also be applied in the first to third embodiments.

[0089] Preferred embodiments of the present invention have been described above in detail, but it should be understood that aspects of the embodiments can be modified, if necessary, to employ aspects, features and concepts of the various patents, applications and publications to provide further embodiments.

[0090] These and other changes can be made to the embodiments in light of the above detailed description.In general, in the claims, the terms used should not be considered limited to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which these claims are entitled.

Claims

1. A time difference measurement method, characterized in that: include: After the image acquisition device is started, a test trigger signal is sent to the image acquisition device, and a test image acquired by the image acquisition device and the test trigger signal are acquired, wherein the test trigger signal includes a first test trigger signal, and the test image includes a first test image and a second test image. The test trigger signal is sent to the image acquisition device, and the test image acquired by the image acquisition device and the test trigger signal are acquired, including: based on a reference time interval of the second test image sent by the image acquisition device, determining a target time interval different from the reference time interval as a time interval of the first test trigger signal; sending the first test trigger signal to the image acquisition device, and acquiring the first test image acquired by the image acquisition device and the first test trigger signal; Selecting one or more of the first test images with a time interval equal to the target time interval from the acquired first test images as target test images, and selecting a target test trigger signal from the first test trigger signal; Based on the output time of the target test image in the test image and the trigger time of the target test trigger signal in the test trigger signal, the trigger output time difference of the image acquisition device is obtained, wherein each of the target test images is acquired by the image acquisition device under the control of a corresponding one of the target test trigger signals.

2. The time difference measurement method according to claim 1, characterized in that: Before determining a target time interval different from the reference time interval of the second test image sent by the image acquisition device as the time interval of the first test trigger signal based on the reference time interval of the second test image, the method further includes: It is determined that the image acquisition device sends the second test image after startup.

3. The time difference measurement method according to claim 1, characterized in that: Before determining a target time interval different from the reference time interval of the second test image sent by the image acquisition device as the time interval of the first test trigger signal based on the reference time interval of the second test image, the method further includes: Determining that the image acquisition device does not send the second test image after being started; Sending a set number of second test trigger signals to the image acquisition device based on a preset time interval, and acquiring the second test image and the second test trigger signal sent by the image acquisition device; It is determined that the image acquisition device has produced an additional image, where the additional image production indicates that a test image produced by the image acquisition device is acquired after a preset time period of stopping producing the second test trigger signal to the image acquisition device.

4. The time difference measurement method according to claim 1, characterized in that: The target test image is the last N first test images acquired, and the target test trigger signal is the last N first test trigger signals acquired, where N is an integer greater than or equal to 1.

5. The time difference measurement method according to claim 1, characterized in that: The step of obtaining a trigger output time difference of the image acquisition device based on the output time of the target test image in the test image and the trigger time of the target test trigger signal in the test trigger signal includes: If the number of the target test image is one, the absolute value of the difference between the image output time of the target test image and the trigger time of the corresponding target test trigger signal is used as the trigger image output time difference of the image acquisition device; If there are multiple target test images, the absolute value of the difference between the image output time of each target test image and the trigger time of the corresponding target test trigger signal is obtained to obtain multiple reference time differences, and the trigger output time difference of the image acquisition device is obtained based on the multiple reference time differences.

6. A time difference measurement system, characterized in that: include: A waveform processing module, and a signal generator communicatively connected to the waveform processing module, wherein the waveform processing module and the signal generator are both communicatively connected to an image acquisition device, and the waveform processing module is used to execute the time difference measurement method according to any one of claims 1 to 5; The image acquisition device is used to acquire a test image after startup, and send the acquired image to the waveform processing module; The signal generator is used to generate a test trigger signal, and send the test trigger signal to the image acquisition device and the waveform processing module respectively.

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