Distance measurement method and device

Abstract

The present invention relates to a distance measurement method and device. The distance measurement method comprises: the distance measurement device transmits an incident light signal in a first time period and a fourth time period, and obtains a first light intensity and a second light intensity respectively; the distance measurement device stops transmitting the incident light signal in a second time period and a third time period, and obtains a second ambient light intensity and a third ambient light intensity of the ambient light respectively; obtains a first difference and a second difference; the first difference is the sum of the first reflected light intensity and the third difference of the first ambient light intensity minus the second ambient light intensity, and the second difference is the sum of the second reflected light intensity and the fourth difference of the fourth ambient light intensity minus the third ambient light intensity, and the third difference has opposite signs to the fourth difference; obtains the sum of the first difference and the second difference; and obtains the distance information between the target object and the distance measurement device according to the sum. According to the embodiment of the present invention, the interference of the ambient light intensity on the distance measurement can be reduced, thereby improving the signal-to-noise ratio and improving the detection accuracy of the distance measurement device.

Description

Technical Field

[0001] The present invention relates to the technical field of distance measuring devices, and in particular to a distance measuring method and device. Background Art

[0002] In the related art, the distance measuring device is easily disturbed by the environment during operation, and a large amount of noise signals exist in the detection data obtained by the distance measuring device. Summary of the invention

[0003] The present invention provides a distance measurement method and device to solve the deficiencies in the related art.

[0004] According to a first aspect of an embodiment of the present invention, a distance measurement method is provided, which is applied to a distance measurement device. The method includes:

[0005] The distance measuring device emits an incident light signal in a first time period and obtains a first light intensity, wherein the first light intensity includes a first reflected light intensity of a first reflected light signal reflected by the target object from the incident light signal and a first ambient light intensity of ambient light;

[0006] The distance measuring device stops emitting the incident light signal within a second time period and acquires a second ambient light intensity of the ambient light;

[0007] The distance measuring device stops emitting the incident light signal within a third time period and acquires a third ambient light intensity of the ambient light;

[0008] The ranging device transmits the incident light signal and obtains a second light intensity in a fourth time period, where the second light intensity includes a second reflected light intensity of a second reflected light signal obtained by reflecting the incident light signal from the target object and a fourth ambient light intensity of ambient light; the first time period, the second time period, the third time period and the fourth time period are connected in sequence and have the same duration;

[0009] Obtain a first difference value of the first light intensity minus the second ambient light intensity, and a second difference value of the fourth light intensity minus the third ambient light intensity; wherein the first difference value is the sum of the first reflected light intensity and the third difference value, the third difference value is the difference value of the first ambient light intensity minus the second ambient light intensity, the second difference value is the sum of the second reflected light intensity and the fourth difference value, the fourth difference value is the difference value of the fourth ambient light intensity minus the third ambient light intensity, and the third difference value has an opposite sign to the fourth difference value;

[0010] Obtaining a sum of the first difference and the second difference;

[0011] The distance information between the target object and the distance measuring device is obtained according to the sum value.

[0012] In one embodiment, the first time period, the second time period, the third time period and the fourth time period connected in sequence constitute a detection cycle;

[0013] Before acquiring the distance information between the target object and the distance measuring device according to the sum value, the distance measuring device performs at least two detection cycles to obtain at least two sum values;

[0014] The obtaining the distance information between the target object and the distance measuring device according to the sum value includes:

[0015] The distance information is obtained according to at least two of the sum values.

[0016] In one embodiment, the ambient light includes the light of an AC lamp; the light intensity of the light changes periodically over time; in each light intensity change cycle, the light intensity of the light gradually increases from a first minimum value to a peak value, and then gradually decreases to a second minimum value, and the first minimum value is the same as the second minimum value;

[0017] Before the distance measuring device emits an incident light signal and obtains a first light intensity within a first time period, the distance measuring device further includes:

[0018] For each light intensity variation cycle, determine a first time point, a second time point and a third time point, wherein the first time point is the time point when the light intensity of the light reaches a first minimum value, the second time point is the time point when the light intensity of the light reaches the peak value, and the third time point is the time point when the light intensity of the light reaches the second minimum value;

[0019] A ranging time interval is determined according to the first time point, the second time point, and the third time point, the first time period, the second time period, the second time period, and the fourth time period are located within the ranging time interval, the ranging time interval is located between the first time point and the second time point, or the ranging time interval is located between the second time point and the third time point.

[0020] In one embodiment, for each light intensity variation cycle, determining the first time point, the second time point, and the third time point includes:

[0021] Obtaining a function of how the light intensity of the light changes over time;

[0022] For each lamp light intensity variation cycle, the first time point, the second time point and the third time point are determined according to the function.

[0023] In one embodiment, the driving current of the AC lamp is an AC current, the frequency of the AC current is 50 Hz, the period of each light intensity change is 10 milliseconds, and the ranging time interval is less than or equal to 5 milliseconds; or,

[0024] The frequency of the alternating current is 60 Hz, the period of each light intensity change is 8.3 milliseconds, and the ranging time interval is less than or equal to 4.15 milliseconds.

[0025] In one embodiment, the first reflected light intensity is the integrated value of the light intensity of the first reflected light signal in the first time period; the first ambient light intensity is the integrated value of the light intensity of the ambient light in the first time period; the second ambient light intensity is the integrated value of the light intensity of the ambient light in the second time period; the third ambient light intensity is the integrated value of the light intensity of the ambient light in the third time period; the second reflected light intensity is the integrated value of the light intensity of the second reflected light signal in the fourth time period; and the fourth ambient light intensity is the integrated value of the light intensity of the ambient light in the fourth time period.

[0026] According to a second aspect of an embodiment of the present invention, there is provided a distance measuring device, including:

[0027] A transmitting module, configured to transmit an incident light signal within a first time period;

[0028] A first acquisition module is configured to acquire a first light intensity within the first time period, wherein the first light intensity includes a first reflected light intensity of a first reflected light signal of the incident light signal reflected by the target object and a first ambient light intensity of ambient light;

[0029] The transmitting module is further configured to stop transmitting the incident light signal within a second time period;

[0030] A second acquisition module is configured to acquire a second ambient light intensity of the ambient light within a second time period;

[0031] The transmitting module is further configured to stop transmitting the incident light signal within a third time period;

[0032] A third acquisition module is configured to acquire a third ambient light intensity of the ambient light within a third time period;

[0033] The transmitting module is further configured to transmit the incident light signal in a fourth time period;

[0034] a fourth acquisition module, configured to acquire a second light intensity in a fourth time period, wherein the second light intensity includes a second reflected light intensity of a second reflected light signal obtained by reflecting the incident light signal from the target object and a fourth ambient light intensity of ambient light; the first time period, the second time period, the third time period and the fourth time period are sequentially connected and have the same duration;

[0035] a fifth acquisition module, configured to acquire a first difference value of the first light intensity minus the second ambient light intensity, and a second difference value of the second light intensity minus the third ambient light intensity; wherein the first difference value is the sum of the first reflected light intensity and the third difference value, the third difference value is the difference value of the first ambient light intensity minus the second ambient light intensity, the second difference value is the sum of the second reflected light intensity and the fourth difference value, the fourth difference value is the difference value of the fourth ambient light intensity minus the third ambient light intensity, and the third difference value has an opposite sign to the fourth difference value;

[0036] A sixth acquisition module is configured to acquire a sum of the first difference and the second difference;

[0037] The seventh acquisition module is configured to acquire the distance information between the target object and the distance measuring device according to the sum value.

[0038] In one embodiment, the ambient light includes the light of an AC lamp, the light intensity of which changes periodically over time; in each light intensity change cycle, the light intensity of the lamp gradually increases from a first minimum value to a peak value, and then gradually decreases to a second minimum value, and the first minimum value is the same as the second minimum value; the distance measuring device further includes:

[0039] The first determining module is configured to determine, for each light intensity variation cycle of the light before the first time period, a first time point, a second time point and a third time point according to the first time point, the first time point being the time point when the light intensity of the light reaches the first minimum value, the second time point being the time point when the light intensity of the light reaches the peak value, and the third time point being the time point when the light intensity of the light reaches the second minimum value;

[0040] The second determining module is configured to determine a ranging time interval according to the first time point, the second time point and the third time point, the first time period, the second time period, the second time period and the fourth time period are located within the ranging time interval, the ranging time interval is located between the first time point and the second time point, or the ranging time interval is located between the second time point and the third time point.

[0041] In one embodiment, the first determining module includes:

[0042] An acquisition submodule, configured to acquire a function of the light intensity of the light changing over time;

[0043] The determination submodule is configured to determine the first time point, the second time point and the third time point according to the function for each lamp light intensity variation cycle.

[0044] In one embodiment, the first reflected light intensity is the integrated value of the light intensity of the first reflected light signal in the first time period; the first ambient light intensity is the integrated value of the light intensity of the ambient light in the first time period; the second ambient light intensity is the integrated value of the light intensity of the ambient light in the second time period; the third ambient light intensity is the integrated value of the light intensity of the ambient light in the third time period; the second reflected light intensity is the integrated value of the light intensity of the second reflected light signal in the fourth time period; and the fourth ambient light intensity is the integrated value of the light intensity of the ambient light in the fourth time period.

[0045] According to the above embodiments, since the ranging device transmits an incident light signal and obtains a first light intensity in the first time period, the first light intensity includes a first reflected light intensity of a first reflected light signal reflected by the target object and a first ambient light intensity of the ambient light, the ranging device stops transmitting the incident light signal in the second time period and obtains a second ambient light intensity of the ambient light, the ranging device stops transmitting the incident light signal in the third time period and obtains a third ambient light intensity of the ambient light, and the ranging device transmits the incident light signal in the fourth time period and obtains a second light intensity, the second light intensity includes a second reflected light signal reflected by the target object. The second reflected light intensity of the signal and the fourth ambient light intensity of the ambient light, at the same time, the first time period, the second time period, the third time period and the fourth time period are connected in sequence and have the same duration, and the distance measuring device obtains the first difference between the first light intensity and the second ambient light intensity, and the second difference between the second light intensity and the third ambient light intensity, wherein the first difference is the sum of the first reflected light intensity and the third difference, the third difference is the difference between the first ambient light intensity and the second ambient light intensity, the second difference is the sum of the second reflected light intensity and the fourth difference, the fourth difference is the difference between the fourth ambient light intensity and the third ambient light intensity, and the third difference has opposite signs to the fourth difference. In this way, since the first light intensity includes the first reflected light intensity and the first ambient light intensity, subtracting the second ambient light intensity from the first ambient light intensity can reduce the interference of the ambient light intensity on the detection value, thereby reducing the noise interference in the first difference, and at the same time, since the second light intensity includes the second reflected light intensity and the fourth ambient light intensity, subtracting the third ambient light intensity from the fourth ambient light intensity can also reduce the interference of the ambient light intensity on the detection value, thereby reducing the noise interference in the second difference. For the same target object, fluctuations in ambient light intensity will affect the detection value. Since the first difference is the sum of the third difference and the first reflected light intensity, and the second difference is the sum of the fourth difference and the second reflected light intensity, and the third difference and the fourth difference have opposite signs, when the ranging device obtains the sum of the first difference and the second difference, the third difference and the fourth difference will offset each other at least in part. Therefore, the interference of ambient light intensity on the detection value can be further reduced. When obtaining the distance information between the target object and the ranging device based on the sum, the signal-to-noise ratio can be improved, and the detection accuracy of the ranging device can be improved.

[0046] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0048] Figure 1 is a flow chart of a distance measurement method according to an embodiment of the present invention;

[0049] Figure 2 is a schematic diagram of a distance measurement method according to an embodiment of the present invention;

[0050] Figure 3 is a schematic diagram of a distance measuring device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0051] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0052] The embodiment of the present invention provides a distance measurement method, which can be applied to a distance measurement device, such as Figure 1 As shown, the ranging method may include the following steps 101 to 107:

[0053] In step 101, a distance measuring device transmits an incident light signal in a first time period and obtains a first light intensity, where the first light intensity includes a first reflected light intensity and a first ambient light intensity.

[0054] like Figure 2 As shown, the distance measuring device transmits an incident light signal in a first time period 201 and obtains a first light intensity, where the first light intensity includes a first reflected light intensity and a first ambient light intensity 21 .

[0055] In step 102, the distance measuring device stops emitting an incident light signal within a second time period and acquires a second ambient light intensity.

[0056] like Figure 2 As shown, the distance measuring device stops emitting the incident light signal and acquires the second ambient light intensity 22 in the second time period 202 .

[0057] In step 103, the distance measuring device stops emitting the incident light signal within a third time period and acquires a third ambient light intensity.

[0058] like Figure 2 As shown, the distance measuring device stops emitting the incident light signal and obtains the third ambient light intensity 23 in the third time period 203 .

[0059] In step 104, the distance measuring device emits an incident light signal in a fourth time period and obtains a second light intensity, where the second light intensity includes a second reflected light intensity and a fourth ambient light intensity; wherein the first time period, the second time period, the third time period and the fourth time period are of the same length.

[0060] like Figure 2 As shown, the ranging device emits an incident light signal in a fourth time period 204 and obtains a second light intensity, wherein the second light intensity includes a second reflected light intensity and a fourth ambient light intensity 24; wherein the first time period 201, the second time period 202, the third time period 203 and the fourth time period 204 are connected in sequence and have the same duration.

[0061] In step 105, a first difference between the first light intensity and the second ambient light intensity is obtained, as is a second difference between the second light intensity and the third ambient light intensity. The first difference is the sum of the first reflected light intensity and the third difference, the third difference is the difference between the first ambient light intensity and the second ambient light intensity, the second difference is the sum of the second reflected light intensity and the fourth difference, the fourth difference is the difference between the fourth ambient light intensity and the third ambient light intensity, and the third difference and the fourth difference have opposite signs.

[0062] like Figure 2 As shown, a first difference of the first light intensity minus the second ambient light intensity 22, and a second difference of the second light intensity minus the third ambient light intensity 23 are obtained; wherein the first difference is the sum of the first reflected light intensity and the third difference 25, the third difference 25 is the difference of the first ambient light intensity 21 minus the second ambient light intensity 22, the third difference 25 can be a positive value, the second difference is the sum of the second reflected light intensity and the fourth difference 26, the fourth difference 26 is the difference of the fourth ambient light intensity minus the third ambient light intensity, the fourth difference 26 is a negative value, and the third difference 25 and the fourth difference 26 have opposite signs.

[0063] In step 106, the distance measuring device obtains the sum of the first difference value and the second difference value.

[0064] In step 107, the distance measuring device obtains the distance information between the target object and the distance measuring device according to the sum value.

[0065] In this embodiment, since the ranging device transmits an incident light signal and obtains a first light intensity in the first time period, the first light intensity includes a first reflected light intensity of a first reflected light signal reflected by the target object and a first ambient light intensity of the ambient light, the ranging device stops transmitting the incident light signal in the second time period and obtains a second ambient light intensity of the ambient light, the ranging device stops transmitting the incident light signal in the third time period and obtains a third ambient light intensity of the ambient light, and the ranging device transmits the incident light signal in the fourth time period and obtains a second light intensity, the second light intensity includes a second reflected light signal reflected by the target object The second reflected light intensity and the fourth ambient light intensity of the ambient light are measured, and at the same time, the first time period, the second time period, the third time period and the fourth time period are connected in sequence and have the same duration, and the distance measuring device obtains the first difference between the first light intensity and the second ambient light intensity, and the second difference between the second light intensity and the third ambient light intensity, wherein the first difference is the sum of the first reflected light intensity and the third difference, the third difference is the difference between the first ambient light intensity and the second ambient light intensity, the second difference is the sum of the second reflected light intensity and the fourth difference, the fourth difference is the difference between the fourth ambient light intensity and the third ambient light intensity, and the third difference has opposite signs to the fourth difference. In this way, since the first light intensity includes the first reflected light intensity and the first ambient light intensity, subtracting the second ambient light intensity from the first ambient light intensity can reduce the interference of the ambient light intensity on the detection value, thereby reducing the noise interference in the first difference. At the same time, since the second light intensity includes the second reflected light intensity and the fourth ambient light intensity, subtracting the third ambient light intensity from the fourth ambient light intensity can also reduce the interference of the ambient light intensity on the detection value, thereby reducing the noise interference in the second difference. For the same target object, fluctuations in ambient light intensity will affect the detection value. Since the first difference is the sum of the third difference and the first reflected light intensity, and the second difference is the sum of the fourth difference and the second reflected light intensity, and the third difference and the fourth difference have opposite signs, when the ranging device obtains the sum of the first difference and the second difference, the third difference and the fourth difference will offset each other at least in part. Therefore, the interference of ambient light intensity on the detection value can be further reduced. When obtaining the distance information between the target object and the ranging device based on the sum, the signal-to-noise ratio can be improved, and the detection accuracy of the ranging device can be improved.

[0066] In some embodiments, the first time period 201, the second time period 202, the third time period 203 and the fourth time period 204 connected in sequence are a detection cycle. Before the ranging device obtains the distance information between the target object and the ranging device according to the sum of the first difference value and the second difference value, the ranging device may perform at least two detection cycles to obtain at least two sum values. In step 107, the ranging device may obtain the distance information according to the at least two sum values. For example, the ranging device may obtain the distance information according to the average value of the at least two sum values. In this way, since the ranging device performs at least two detection cycles to obtain at least two sum values, and obtains the distance information according to the at least two sum values, the detection error is reduced, and the ranging accuracy of the ranging device can be improved.

[0067] In some embodiments, the ambient light includes the light of an AC lamp. For example, the function of the driving current of the AC lamp changing with time is a sine function, but is not limited thereto. The light intensity of the lamp changes periodically with time. For example, in each light intensity change cycle, the equation of the light intensity changing with time is a parabolic equation. In each light intensity change cycle, the light intensity of the lamp gradually increases from a first minimum value to a peak value, and then gradually decreases to a second minimum value, and the first minimum value is the same as the second minimum value. In this ranging scenario, before step 101, the following steps are also included:

[0068] First, for each light intensity change cycle, determine the first time point, the second time point and the third time point, wherein the first time point is the time point when the light intensity is the first minimum value, the second time point is the time point when the light intensity is the peak value, and the third time point is the time point when the light intensity is the second minimum value.

[0069] Then, according to the first time point, the second time point and the third time point, the ranging time interval is determined, wherein the first time period 201, the second time period 202, the second time period 203 and the fourth time period 204 are located within the ranging time interval, the ranging time interval is located between the first time point and the second time point, or the ranging time interval is located between the second time point and the third time point. In this way, the ranging time interval can be determined by determining the change cycle of the light intensity, thereby ensuring that the ranging time interval is located between the first time point and the second time point, or between the second time point and the third time point, and further, ensuring that the third difference and the fourth difference have opposite signs, thereby canceling the ambient light intensity values ​​in the first difference and the second difference to improve the signal-to-noise ratio and the detection accuracy of the ranging device.

[0070] In some embodiments, for each light intensity variation cycle, according to the step of determining the first time point, the second time point and the third time point, the following steps may be included:

[0071] First, a function of how the light intensity of the light changes over time is obtained. For example, data of the light intensity of the light in different time periods may be collected, and then the function of how the light intensity of the light changes over time may be obtained by fitting the collected data, but the present invention is not limited thereto.

[0072] Then, for each light intensity change cycle, the first time point, the second time point and the third time point are determined according to the function of the light intensity changing with time. In this way, the first time point, the second time point and the third time point can be accurately obtained, so that the ranging time interval can be accurately determined, and then, it can be further ensured that the third difference and the fourth difference have opposite signs, so that the ambient light intensity values ​​in the first difference and the second difference are cancelled to improve the signal-to-noise ratio and improve the detection accuracy of the ranging device.

[0073] In some embodiments, the driving current of the AC lamp is an AC current, the frequency of the AC current is 50 Hz, the period of each lamp light intensity change is 10 milliseconds, and the ranging time interval is less than or equal to 5 milliseconds. Thus, when the frequency of the AC current is 50 Hz, the ranging time interval is less than or equal to 5 milliseconds, which can ensure that the ranging time interval is between the first time point and the second time point, or between the second time point and the third time point, thereby further ensuring that the third difference and the fourth difference have opposite signs, thereby canceling the ambient light intensity values ​​in the first difference and the second difference to improve the signal-to-noise ratio and the detection accuracy of the ranging device.

[0074] In some embodiments, the frequency of the alternating current is 60 Hz, the period of each light intensity change is 8.3 milliseconds, and the ranging time interval is less than or equal to 4.15 milliseconds. Thus, when the frequency of the alternating current is 60 Hz, the ranging time interval is less than or equal to 8.3 milliseconds, which can ensure that the ranging time interval is between the first time point and the second time point, or between the second time point and the third time point, thereby further ensuring that the third difference and the fourth difference have opposite signs, thereby canceling the ambient light intensity values ​​in the first difference and the second difference to improve the signal-to-noise ratio and the detection accuracy of the ranging device.

[0075] In some embodiments, the first reflected light intensity is the integral value of the light intensity of the first reflected light signal in the first time period 201, that is, the first reflected light intensity is the cumulative value of the light intensity of the first reflected light signal in the first time period 201, the first ambient light intensity 21 is the integral value of the light intensity of the ambient light in the first time period 201, that is, the first ambient light intensity 21 is the cumulative value of the light intensity of the ambient light in the first time period 201, and the second ambient light intensity 22 is the integral value of the light intensity of the ambient light in the second time period 202, that is, the second ambient light intensity 22 is the integral value of the light intensity of the ambient light in the second time period 202. The third ambient light intensity 23 is the integral value of the ambient light intensity in the third time period 203, that is, the third ambient light intensity 23 is the integral value of the ambient light intensity in the third time period 203, the second reflected light intensity is the integral value of the second reflected light signal intensity in the fourth time period 204, that is, the second reflected light intensity is the integral value of the second reflected light signal intensity in the fourth time period 204, the fourth ambient light intensity 24 is the integral value of the ambient light intensity in the fourth time period 204, and the fourth ambient light intensity 24 is the integral value of the ambient light intensity in the fourth time period 204. In this way, the total light intensity value in a certain time period can be accurately obtained, thereby improving the accuracy of the data, and further, improving the detection accuracy of the distance measuring device.

[0076] The embodiment of the present invention also provides a distance measuring device, such as Figure 3 As shown, the distance measuring device comprises:

[0077] The transmitting module 31 is configured to transmit an incident light signal in a first time period 201 , stop transmitting the incident light signal in a second time period 202 , stop transmitting the incident light signal in a third time period 203 , and transmit the incident light signal in a fourth time period 204 .

[0078] The first acquisition module 32 is configured to acquire a first light intensity in a first time period 201 , wherein the first light intensity includes a first reflected light intensity of a first reflected light signal of an incident light signal reflected by a target object and a first ambient light intensity 21 of ambient light.

[0079] The second acquisition module 33 is configured to acquire a second ambient light intensity 22 of the ambient light in the second time period 202 .

[0080] The third acquisition module 34 is configured to acquire a third ambient light intensity 23 of the ambient light in the third time period 203 .

[0081] The fourth acquisition module 35 is configured to acquire the second light intensity in the fourth time period 204, where the second light intensity includes the second reflected light intensity of the second reflected light signal reflected by the target object from the incident light signal and the fourth ambient light intensity 24 of the ambient light. The first time period 201, the second time period 202, the second time period 202 and the fourth time period 204 are sequentially connected and have the same duration.

[0082] The fifth acquisition module 36 is configured to obtain a first difference between the first light intensity and the second ambient light intensity, and a second difference between the second light intensity and the third ambient light intensity; wherein the first difference is the sum of the first reflected light intensity and the third difference, the third difference is the difference between the first ambient light intensity and the second ambient light intensity, the second difference is the sum of the second reflected light intensity and the fourth difference, the fourth difference is the difference between the fourth ambient light intensity and the third ambient light intensity, and the signs of the third difference and the fourth difference are opposite.

[0083] The sixth acquisition module 37 is configured to acquire a sum of the first difference and the second difference.

[0084] The seventh acquisition module 38 is configured to acquire the distance information between the target object and the distance measuring device according to the sum value.

[0085] In this embodiment, since the transmitting module transmits the incident light signal in the first time period, stops transmitting the incident light signal in the second time period, stops transmitting the incident light signal in the third time period, and transmits the incident light signal in the fourth time period, the first acquisition module obtains the first light intensity in the first time period, and the first light intensity includes the first reflected light intensity and the first ambient light intensity, the second acquisition module obtains the second ambient light intensity in the second time period, the third acquisition module obtains the third ambient light intensity in the third time period, and the fourth acquisition module 35 obtains the second light intensity in the fourth time period, and the second light intensity includes the second reflected light intensity and the fourth ambient light intensity, and the first time period, the second time period, the third time period and the fourth time period have the same duration. The fifth acquisition module obtains the first difference between the first light intensity and the second ambient light intensity, and the second difference between the second light intensity and the third ambient light intensity, wherein the first difference is the sum of the first reflected light intensity and the third difference, the third difference is the difference between the first ambient light intensity and the second ambient light intensity, the second difference is the sum of the second reflected light intensity and the fourth difference, the fourth difference is the difference between the fourth ambient light intensity and the third ambient light intensity, and the third difference has opposite signs to the fourth difference. In this way, since the first light intensity includes the first reflected light intensity and the first ambient light intensity, subtracting the second ambient light intensity from the first ambient light intensity can reduce the interference of the ambient light intensity on the detection value, thereby reducing the noise interference in the first difference. At the same time, since the second light intensity includes the second reflected light intensity and the fourth ambient light intensity, subtracting the third ambient light intensity from the fourth ambient light intensity can also reduce the interference of the ambient light intensity on the detection value, thereby reducing the noise interference in the second difference. For the same target object, the fluctuation of the ambient light intensity will affect the detection value. Since the first difference is the sum of the third difference and the first reflected light intensity, and the second difference is the sum of the fourth difference and the second reflected light intensity, and the third difference and the fourth difference have opposite signs, when the distance measuring device obtains the sum of the first difference and the second difference, the third difference and the fourth difference will offset each other at least in part. Therefore, the interference of the ambient light intensity on the detection value can be further reduced. When the distance information between the target object and the distance measuring device is obtained according to the sum, the signal-to-noise ratio can be improved, and the detection accuracy of the distance measuring device can be improved.

[0086] In some embodiments, the ambient light includes the light of an AC lamp, the light intensity of the light changes periodically over time; in each light intensity change cycle, the light intensity of the light gradually increases from a first minimum value to a peak value, and then gradually decreases to a second minimum value, and the first minimum value is the same as the second minimum value; the distance measuring device further includes:

[0087] The first determination module is configured to determine, for each light intensity change cycle before the first time period 201, a first time point, a second time point and a third time point, wherein the first time point is a time point when the light intensity of the light is a first minimum value, the second time point is a time point when the light intensity of the light is a peak value, and the third time point is a time point when the light intensity of the light is a second minimum value;

[0088] The second determination module is configured to determine the ranging time interval according to the first time point, the second time point and the third time point, wherein the first time period 201, the second time period 202, the second time period 203 and the fourth time period 204 are located within the ranging time interval, the ranging time interval is located between the first time point and the second time point, or the ranging time interval is located between the second time point and the third time point.

[0089] In this way, the ranging time interval can be determined by determining the variation cycle of the light intensity, thereby ensuring that the ranging time interval is between the first time point and the second time point, or between the second time point and the third time point, and further ensuring that the third difference and the fourth difference have opposite signs, thereby canceling out the ambient light intensity values ​​in the first difference and the second difference to improve the signal-to-noise ratio and the detection accuracy of the ranging device.

[0090] In some embodiments, the first determining module includes:

[0091] An acquisition submodule is configured to acquire a function of light intensity varying with time;

[0092] The determination submodule is configured to determine the first time point, the second time point and the third time point according to the function for each light intensity change cycle. In this way, the first time point, the second time point and the third time point can be accurately obtained, so that the ranging time interval can be accurately determined, and then, it can be further ensured that the third difference and the fourth difference have opposite signs so that the ambient light intensity values ​​in the first difference and the second difference cancel each other to improve the signal-to-noise ratio and improve the detection accuracy of the ranging device.

[0093] In some embodiments, the first reflected light intensity is the integral value of the light intensity of the first reflected light signal in the first time period 201, that is, the first reflected light intensity is the cumulative value of the light intensity of the first reflected light signal in the first time period 201, the first ambient light intensity 21 is the integral value of the light intensity of the ambient light in the first time period 201, that is, the first ambient light intensity 21 is the cumulative value of the light intensity of the ambient light in the first time period 201, and the second ambient light intensity 22 is the integral value of the light intensity of the ambient light in the second time period 202, that is, the second ambient light intensity 22 is the integral value of the light intensity of the ambient light in the second time period 202. The third ambient light intensity 23 is the integral value of the ambient light intensity in the third time period 203, that is, the third ambient light intensity 23 is the integral value of the ambient light intensity in the third time period 203, the second reflected light intensity is the integral value of the second reflected light signal intensity in the fourth time period 204, that is, the second reflected light intensity is the integral value of the second reflected light signal intensity in the fourth time period 204, the fourth ambient light intensity 24 is the integral value of the ambient light intensity in the fourth time period 204, and the fourth ambient light intensity 24 is the integral value of the ambient light intensity in the fourth time period 204. In this way, the total light intensity value in a certain time period can be accurately obtained, thereby improving the accuracy of the data, and further, improving the detection accuracy of the distance measuring device.

[0094] In the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. The term "plurality" refers to two or more than two, unless otherwise clearly defined.

[0095] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the disclosure disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The description and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0096] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A distance measurement method, characterized in that: Applied to a distance measuring device, the method comprises: The distance measuring device emits an incident light signal in a first time period and obtains a first light intensity, wherein the first light intensity includes a first reflected light intensity of a first reflected light signal reflected by the target object from the incident light signal and a first ambient light intensity of ambient light; The distance measuring device stops emitting the incident light signal within a second time period and acquires a second ambient light intensity of the ambient light; The distance measuring device stops emitting the incident light signal within a third time period and acquires a third ambient light intensity of the ambient light; The ranging device transmits the incident light signal and obtains a second light intensity in a fourth time period, where the second light intensity includes a second reflected light intensity of a second reflected light signal obtained by reflecting the incident light signal from the target object and a fourth ambient light intensity of ambient light; the first time period, the second time period, the third time period and the fourth time period are connected in sequence and have the same duration; Obtain a first difference value of the first light intensity minus the second ambient light intensity, and a second difference value of the second light intensity minus the third ambient light intensity; wherein the first difference value is the sum of the first reflected light intensity and the third difference value, the third difference value is the difference value of the first ambient light intensity minus the second ambient light intensity, the second difference value is the sum of the second reflected light intensity and the fourth difference value, the fourth difference value is the difference value of the fourth ambient light intensity minus the third ambient light intensity, and the third difference value has an opposite sign to the fourth difference value; Obtaining a sum of the first difference and the second difference; The distance information between the target object and the distance measuring device is obtained according to the sum value.

2. The distance measurement method according to claim 1, characterized in that: The first time period, the second time period, the third time period and the fourth time period connected in sequence constitute a detection cycle; Before acquiring the distance information between the target object and the distance measuring device according to the sum value, the distance measuring device performs at least two detection cycles to obtain at least two sum values; The obtaining the distance information between the target object and the distance measuring device according to the sum value includes: The distance information is obtained according to at least two of the sum values.

3. The distance measurement method according to claim 1, characterized in that: The ambient light includes the light of an AC lamp; the light intensity of the light changes periodically over time; in each light intensity change cycle, the light intensity of the light gradually increases from a first minimum value to a peak value, and then gradually decreases to a second minimum value, and the first minimum value is the same as the second minimum value; Before the distance measuring device emits an incident light signal and obtains a first light intensity within a first time period, the distance measuring device further includes: For each light intensity variation cycle, determine a first time point, a second time point and a third time point, wherein the first time point is the time point when the light intensity of the light reaches a first minimum value, the second time point is the time point when the light intensity of the light reaches the peak value, and the third time point is the time point when the light intensity of the light reaches the second minimum value; A ranging time interval is determined according to the first time point, the second time point, and the third time point, the first time period, the second time period, the second time period, and the fourth time period are located within the ranging time interval, the ranging time interval is located between the first time point and the second time point, or the ranging time interval is located between the second time point and the third time point.

4. The distance measurement method according to claim 3, characterized in that: The method of determining the first time point, the second time point and the third time point for each light intensity variation cycle includes: Obtaining a function of how the light intensity of the light changes over time; For each lamp light intensity variation cycle, the first time point, the second time point and the third time point are determined according to the function.

5. The distance measurement method according to claim 3, characterized in that: The driving current of the AC lamp is an AC current, the frequency of the AC current is 50 Hz, the period of each light intensity change is 10 milliseconds, and the ranging time interval is less than or equal to 5 milliseconds; or, The frequency of the alternating current is 60 Hz, the period of each light intensity change is 8.3 milliseconds, and the ranging time interval is less than or equal to 4.15 milliseconds.

6. The distance measurement method according to claim 1, characterized in that: The first reflected light intensity is the integrated value of the light intensity of the first reflected light signal in the first time period; the first ambient light intensity is the integrated value of the light intensity of the ambient light in the first time period; the second ambient light intensity is the integrated value of the light intensity of the ambient light in the second time period; the third ambient light intensity is the integrated value of the light intensity of the ambient light in the third time period; the second reflected light intensity is the integrated value of the light intensity of the second reflected light signal in the fourth time period; and the fourth ambient light intensity is the integrated value of the light intensity of the ambient light in the fourth time period.

7. A distance measuring device, characterized in that: include: A transmitting module, configured to transmit an incident light signal within a first time period; A first acquisition module is configured to acquire a first light intensity within the first time period, wherein the first light intensity includes a first reflected light intensity of a first reflected light signal of the incident light signal reflected by the target object and a first ambient light intensity of ambient light; The transmitting module is further configured to stop transmitting the incident light signal within a second time period; A second acquisition module is configured to acquire a second ambient light intensity of the ambient light within a second time period; The transmitting module is further configured to stop transmitting the incident light signal within a third time period; A third acquisition module is configured to acquire a third ambient light intensity of the ambient light within a third time period; The transmitting module is further configured to transmit the incident light signal in a fourth time period; a fourth acquisition module, configured to acquire a second light intensity in a fourth time period, wherein the second light intensity includes a second reflected light intensity of a second reflected light signal obtained by reflecting the incident light signal from the target object and a fourth ambient light intensity of ambient light; the first time period, the second time period, the third time period and the fourth time period are sequentially connected and have the same duration; a fifth acquisition module, configured to acquire a first difference value of the first light intensity minus the second ambient light intensity, and a second difference value of the second light intensity minus the third ambient light intensity; wherein the first difference value is the sum of the first reflected light intensity and the third difference value, the third difference value is the difference value of the first ambient light intensity minus the second ambient light intensity, the second difference value is the sum of the second reflected light intensity and the fourth difference value, the fourth difference value is the difference value of the fourth ambient light intensity minus the third ambient light intensity, and the third difference value has an opposite sign to the fourth difference value; A sixth acquisition module is configured to acquire a sum of the first difference and the second difference; The seventh acquisition module is configured to acquire the distance information between the target object and the distance measuring device according to the sum value.

8. The distance measuring device according to claim 7, characterized in that: The ambient light includes the light of an AC lamp, the light intensity of which changes periodically over time; in each light intensity change cycle, the light intensity of the light gradually increases from a first minimum value to a peak value, and then gradually decreases to a second minimum value, and the first minimum value is the same as the second minimum value; the distance measuring device also includes: The first determining module is configured to determine, for each light intensity variation cycle of the light before the first time period, a first time point, a second time point and a third time point according to the first time point, the first time point being the time point when the light intensity of the light reaches the first minimum value, the second time point being the time point when the light intensity of the light reaches the peak value, and the third time point being the time point when the light intensity of the light reaches the second minimum value; The second determining module is configured to determine a ranging time interval according to the first time point, the second time point and the third time point, the first time period, the second time period, the second time period and the fourth time period are located within the ranging time interval, the ranging time interval is located between the first time point and the second time point, or the ranging time interval is located between the second time point and the third time point.

9. The distance measuring device according to claim 8, characterized in that: The first determining module includes: An acquisition submodule, configured to acquire a function of the light intensity of the light changing over time; The determination submodule is configured to determine the first time point, the second time point and the third time point according to the function for each lamp light intensity variation cycle.

10. The distance measuring device according to claim 7, characterized in that: The first reflected light intensity is the integrated value of the light intensity of the first reflected light signal in the first time period; the first ambient light intensity is the integrated value of the light intensity of the ambient light in the first time period; the second ambient light intensity is the integrated value of the light intensity of the ambient light in the second time period; the third ambient light intensity is the integrated value of the light intensity of the ambient light in the third time period; the second reflected light intensity is the integrated value of the light intensity of the second reflected light signal in the fourth time period; and the fourth ambient light intensity is the integrated value of the light intensity of the ambient light in the fourth time period.

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