WO2022126429A1

WO2022126429A1 - Ranging apparatus, ranging method, and movable platform

Info

Publication number: WO2022126429A1
Application number: PCT/CN2020/136824
Authority: WO
Inventors: 马亮亮; 王栗
Original assignee: 深圳市大疆创新科技有限公司
Priority date: 2020-12-16
Filing date: 2020-12-16
Publication date: 2022-06-23
Also published as: CN114556151A

Abstract

A ranging apparatus, a ranging method, and a movable platform, the ranging apparatus (100) comprising: optical emitters (110), an optical system, a first receiving circuit (120a), a second receiving circuit (120b), and a processing module (130), the optical emitters (110) being used for sequentially emitting optical pulse signals; at least some of the echo signals of the optical pulse signals reflected by an object are gathered by the optical system and then received by the first receiving circuit (120a); the second receiving circuit (120b) and the first receiving circuit (120a) are started at the same time, and the optical signals received by the first receiving circuit (120a) and the second receiving circuit (120b) are respectively a first optical signal and a second optical signal; and the processing module (130) is used for determining on the basis of the strength of the first optical signal and the second optical signal whether the first optical signal is noise. The present solution can improve the anti-interference performance of the ranging apparatus.

Description

Distance measuring device, distance measuring method and movable platform

manual

technical field

The present invention generally relates to the technical field of ranging, and more particularly, to a ranging device, a ranging method and a movable platform.

Background technique

Laser ranging devices detect the distance, orientation, shape and other parameters of the measured object by emitting laser pulse signals. As an advanced sensor device that can perceive three-dimensional information of the environment, laser ranging devices have been used in various intelligent robots, assisted driving, etc. , autonomous driving and other fields have been widely used.

The laser ranging device mainly obtains the distance, azimuth, shape and other parameters of the measured object by transmitting optical pulse signals to the measured object, and then comparing the received signal reflected from the measured object with the transmitted signal. However, in addition to receiving the echo signal returned by the measured object, the laser ranging device will also receive noise, and the existence of noise will affect the ranging device's judgment on the measured object. Whether the received signal is noise is an urgent problem to be solved at present.

SUMMARY OF THE INVENTION

A series of concepts in simplified form have been introduced in the Summary section, which are described in further detail in the Detailed Description section. The Summary of the Invention section of the present invention is not intended to attempt to limit the key features and essential technical features of the claimed technical solution, nor is it intended to attempt to determine the protection scope of the claimed technical solution.

In view of the deficiencies of the prior art, the first aspect of the embodiments of the present invention provides a distance measuring device, the distance measuring device includes an optical transmitter, an optical system, a first receiving circuit, a second receiving circuit, and a processing module:

The optical transmitter is used for sequentially transmitting optical pulse signals;

At least part of the echo signal reflected by the object of the optical pulse signal is collected by the optical system and then received by the first receiving circuit;

The second receiving circuit and the first receiving circuit are turned on at the same time, and the optical signals received by the first receiving circuit and the second receiving circuit in the same period are the first optical signal and the second optical signal respectively;

The processing module is configured to determine whether the first optical signal is noise according to the intensities of the first optical signal and the second optical signal.

A second aspect of the embodiments of the present invention provides a ranging method, where the ranging method includes:

turn on the light transmitter to emit light pulse signal;

The first receiving circuit and the second receiving circuit are simultaneously turned on, and the first receiving circuit receives at least part of the echo signal of the optical pulse signal after being converged by the optical system;

Whether the first optical signal is noise is determined according to the intensities of the first optical signal and the second optical signal, wherein the first optical signal and the second optical signal are the first receiving circuit and the first receiving circuit, respectively. The optical signals received by the two receiving circuits at the same time period.

A third aspect of the embodiments of the present invention provides a movable platform, where the movable platform includes:

A movable platform body; and the distance measuring device provided in the first aspect of the embodiment of the present invention, the distance measuring device is mounted on the movable platform body.

In the ranging device, the ranging method and the movable platform according to the embodiments of the present invention, at least part of the echo signals of the optical pulse signal emitted by the optical transmitter reflected by the object are collected by the optical system and then received by the first receiving circuit, and the second receiving circuit The circuit and the first receiving circuit are turned on at the same time, and the optical signals received by the first receiving circuit and the second receiving circuit in the same period are the first optical signal and the second optical signal, respectively, according to the difference between the first optical signal and the second optical signal. The intensity determines whether the first optical signal is noise, thereby improving the anti-interference performance of the distance measuring device.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative labor.

FIG. 1 shows a structural block diagram of a distance measuring apparatus according to an embodiment of the present invention;

FIG. 2 shows a schematic diagram of the spatial layout of a distance measuring device according to an embodiment of the present invention;

FIG. 3 shows an optical path diagram of a distance measuring device according to an embodiment of the present invention;

FIG. 4 shows a circuit diagram of a receiving circuit of a ranging device according to an embodiment of the present invention;

5 shows a circuit diagram of a receiving circuit of a distance measuring device according to another embodiment of the present invention;

Fig. 6 shows a schematic flowchart of a ranging method according to an embodiment of the present invention.

Detailed ways

In order to make the objects, technical solutions and advantages of the present invention more apparent, exemplary embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of the embodiments of the present invention, and it should be understood that the present invention is not limited by the example embodiments described herein. Based on the embodiments of the present invention described in the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without one or more of these details. In other instances, some technical features known in the art have not been described in order to avoid obscuring the present invention.

It should be understood that the present invention may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the/the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It should also be understood that the terms "compose" and/or "include", when used in this specification, identify the presence of stated features, integers, steps, operations, elements and/or components, but do not exclude one or more other The presence or addition of features, integers, steps, operations, elements, parts and/or groups. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

For a thorough understanding of the present invention, detailed structures will be presented in the following description in order to explain the technical solutions proposed by the present invention. Alternative embodiments of the present invention are described in detail below, however, the invention is capable of other embodiments in addition to these detailed descriptions.

The distance measuring device, the distance measuring method and the movable platform of the present application will be described in detail below with reference to the accompanying drawings. The features of the embodiments and implementations described below may be combined with each other without conflict.

First, with reference to FIG. 1 , the structure of a distance measuring apparatus in an embodiment of the present invention is described in detail and exemplarily. The ranging apparatus in the embodiment of the present invention may be an electronic device such as a laser radar or a laser ranging device. In one embodiment, the ranging device is used to sense external environmental information, for example, distance information, orientation information, reflection intensity information, speed information and the like of environmental objects.

In an implementation manner, the ranging device can detect the distance from the detected object to the ranging device by measuring the time of light propagation between the ranging device and the detected object, that is, Time-of-Flight (TOF). Alternatively, the ranging device can also detect the distance from the detected object to the ranging device through other techniques, such as a ranging method based on phase shift measurement, or a ranging method based on frequency shift measurement. This does not limit.

As shown in FIG. 1 , the distance measuring device 100 according to the embodiment of the present invention includes an optical transmitter 110 , an optical system (not shown), a receiving circuit 120 and a processing module 130 .

Wherein, the light transmitter 110 is used for sequentially transmitting light pulse signals. The number of light emitters 110 may be one or more. The directions of the optical pulse signals emitted by different optical transmitters 110 are the same or different. Preferably, the directions of the optical pulse signals emitted by different optical transmitters 110 are different, and multiple optical transmitters are packaged together or individually. Alternatively, the light transmitter 110 may be a laser. The receiving circuit 120 is used for receiving optical signals.

The receiving circuit 120 includes at least a first receiving circuit 120a and a second receiving circuit 120b. At least part of the echo signals of the optical pulse signal emitted by the optical transmitter 110 reflected by the object are collected by the optical system and then received by the first receiving circuit 120a. The second receiving circuit 120b and the first receiving circuit 120a are turned on at the same time, and the optical signals received by the first receiving circuit 120a and the second receiving circuit 120b in the same period are the first optical signal and the second optical signal, respectively. That is, within the time range in which the first receiving circuit 120a is turned on to receive at least part of the echo signals of the optical pulse signal emitted by the corresponding optical transmitter and collected by the optical system, the second receiving circuit 120b is also turned on at the same time, and the first receiving circuit 120b is also turned on at the same time. The circuit 120a receives the first optical signal, while the second receiving circuit 120b receives the second optical signal. The processing module 130 is configured to determine whether the first optical signal is noise according to the intensities of the first optical signal and the second optical signal, thereby improving the anti-interference performance of the laser ranging device.

For ease of description, in this embodiment of the present invention, the optical transmitter that is turned on in the current time range is referred to as the first optical transmitter 110a, and at least part of the echo signal of the optical pulse signal emitted by the first optical transmitter 110a is reflected by the object. After the optical system is converged, it is received by the first receiving circuit 120a. The receiving circuit that is turned on within the same time range as the first receiving circuit 120a is called the second receiving circuit 120b, and the optical transmitter corresponding to the second receiving circuit 120b is called the second receiving circuit 120b. It is the second optical transmitter 110b. The second optical transmitter 110b is not turned on in the current time range, so it is represented by a dotted line in FIG. 1. It should be noted that there may be multiple optical transmitters in this embodiment of the present application. At least some of the light emitters can be turned on in sequence in different time ranges to emit light pulse signals.

When the receiving circuit is turned on to receive the optical signal, the received optical signal may include the echo signal of the optical pulse signal emitted by the optical transmitter and reflected by the measured object, but may also include noise. Among them, the noise may be a flood light signal, for example, the stray light from other directions is incident on the photoelectric converter after multiple reflections inside the ranging device, and the intensity of such noise is relatively weak. The noise may also be the light emitted by other light sources in the working scene of the ranging device, which is the same or parallel to the receiving optical path of the ranging device. This kind of noise is very strong, even much stronger than the echo signal returned by the measured object.

In order to distinguish the noise from the echo signal, the processing module 130 compares the intensities of the first optical signal received by the first receiving circuit 120a and the second optical signal received by the second receiving circuit 120b, and judges the first optical signal according to the comparison result. whether it is noise.

Referring to FIG. 3 , the optical pulse signal emitted by the first optical transmitter is irradiated into the field of view (FOV) corresponding to the first optical transmitter, and the echo signal 304 reflected by the measured object in the field of view is converged by the optical system 303 to the first photoelectric converter 301 in the first receiving circuit, at this time, the first receiving circuit is in an on state, and the first photoelectric converter 301 can receive the optical signal, that is, the optical signal received by the first photoelectric converter 301 at this time. The signal includes at least part of the echo signal. When the first receiving circuit is turned on, the second receiving circuit is also turned on. Since the second receiving circuit does not correspond to the currently turned on first optical transmitter, the optical system 303 will not condense the echo signals into the second receiving circuit. On the second photoelectric converter 302, the second photoelectric converter 302 cannot receive the echo signal, but can only receive noise, such as the optical signal reflected by the stray light 305 in other directions inside the ranging device, and the signal is a relatively strong signal. Weak floodlight signal. It can be seen from this that if the optical signal received by the first receiving circuit includes an echo signal and the second receiving circuit receives a flood light signal, the intensity of the second optical signal received by the second receiving circuit will be much lower than The strength of the first optical signal received by the first receiving circuit.

On the contrary, if there is no echo signal in the current time range, then the first receiving circuit and the second receiving circuit receive both flood light signals, then because the reflected stray light does not have strong directivity, the light in all directions The difference in intensity distribution is relatively small, so the first optical signal received by the first receiving circuit and the second optical signal received by the second optical signal have similar intensities.

Therefore, in one embodiment, if the ratio of the intensity of the first optical signal to the second optical signal is less than or equal to the first threshold, the processing module 130 determines that the first optical signal is noise. As an example, the value range of the first threshold is (0, 3], and within this value range, it can be considered that the intensity ratio of the first optical signal and the second optical signal is similar.

Further, as described above, when the first optical signal includes an echo signal, the intensity of the first optical signal is much greater than that of the second optical signal; at the same time, limited by factors such as the power of the optical transmitter, the first optical signal The intensity of the optical signal will not be infinitely greater than the intensity of the second optical signal. Therefore, if the intensity ratio of the first optical signal and the second optical signal is between the second threshold and the third threshold, the processing module 130 determines the first optical signal. not noise, where the second threshold is less than the third threshold. It can be understood that the second threshold is greater than or equal to the above-mentioned first threshold. The specific values of the second threshold and the third threshold may be set according to the parameters of the ranging device and the application scenario of the ranging device and other factors.

Using the above judgment method, it can be effectively judged whether the first optical signal received by the first receiving circuit 120a is noise. When judging that the first optical signal is not noise, the processing module 130 may perform ranging according to the first optical signal; when the first optical signal is noise, the processing module 130 may not use the first optical signal to perform ranging, optionally , the processing module 130 can filter the first optical signal, thereby effectively eliminating noise caused by stray light and reducing the generation of noise in the point cloud.

It can be understood that the second optical signal is only used for the purpose of comparison, and the processing module 130 does not perform distance measurement according to the second optical signal.

In another case, the noise incident to the first receiving circuit is the light parallel to the receiving optical path emitted by other light sources (such as lidars of other vehicles in the road scene), then the first receiving circuit receives the first The strength of an optical signal will be much greater than the strength of the second optical signal received by the second receiving circuit. Therefore, in one embodiment, if the ratio of the first optical signal to the second optical signal is greater than or equal to a fourth threshold, the processing module 130 determines that the first optical signal is noise. Wherein, the fourth threshold is greater than the above-mentioned third threshold.

The fourth threshold may be set according to factors such as the parameters of the ranging device and the application scenario of the ranging device. As an example, the fourth threshold may be determined according to the intensity of the light pulse signal emitted by each light transmitter 110 . Specifically, the intensity range P1-P2 of the flood light signal received by the receiving circuit 120 can be predetermined when there is no echo signal, and the maximum intensity of the optical pulse signal transmitted by the optical transmitter 110 is Pmax. When the ratio of the two optical signals is greater than or equal to Pmax/P1, it can be considered that the first optical signal includes direct light from other light sources parallel to the current receiving optical path, so it can be determined that the first optical signal is noise.

Using the above judgment method, it can be effectively judged whether the first optical signal includes light from other light sources, so that the influence of other light sources can be suppressed.

In some embodiments, the receiving circuit 120 may include more than two second receiving circuits 120b, and the processing module 130 integrates the second optical signals of the two or more second receiving circuits 120b to compare with the first optical signals, thereby improving the judge the accuracy of the results. For example, the processing module 130 determines the first optical signal as noise. Alternatively, the processing module 130 determines that the first optical signal is not noise.

In some embodiments, the first receiving circuit 120a includes a first photoelectric converter for receiving an optical signal and converting the optical signal into an electrical signal; the ranging apparatus 100 further includes a first sampling circuit, the first The sampling circuit is connected to the first receiving circuit 120a and the processing module 130, and is used for sampling the electrical signal output by the first receiving circuit 120a to obtain a sampling signal, and sending the sampling signal to the processing module 130. The processing module 130 determines the intensity of the optical signal according to the sampled signal.

In some embodiments, the second receiving circuit 120b includes a second photoelectric converter for receiving an optical signal and converting the optical signal into an electrical signal; the distance measuring device 100 further includes a second sampling circuit, the second The sampling circuit is connected to the second receiving circuit and the processing module, and is used for sampling the electrical signal output by the second receiving circuit to obtain a sampling signal, and sending the sampling signal to the processing module 130 , the processing module 130 determines the intensity of the optical signal according to the sampled signal. Optionally, the first photoelectric converter and the second photoelectric converter include APD (avalanche photodiode), PIN photodiode or other photosensitive devices. Each photoelectric converter may include one or more photosensitive devices, for example, each photoelectric converter may include one or more APDs in an APD array. After the light beam emitted by the light transmitter 110 is reflected by the measured object, the echoes returned by the measured object in different fields of view are collected by the optical system to the photoelectric converters located at different positions, and the photosensitive surfaces of the photoelectric converters are detected. When light is irradiated, the photogenerated carriers drift under the action of the electric field, and a photocurrent is generated in the external circuit.

Exemplarily, the ranging device 100 includes at least three photoelectric converters. Exemplarily, among the at least three photoelectric converters, at least some of the photoelectric converters are arranged at equal intervals. For example, a plurality of photoelectric converters may be arranged in a line array or an area array at equal intervals, and each photoelectric converter may correspond to a field of view area of the same size. Exemplarily, among the at least three photoelectric converters, at least some of the photoelectric converters are arranged at unequal intervals. For example, the photoelectric converters corresponding to part of the field of view (such as the central field of view) can be arranged relatively densely to collect more information, while the photoelectric converters corresponding to other parts of the field of view (such as the edge field of view) can relatively sparsely arranged.

The receiving circuit 120 may further include a current-voltage converting circuit, which is connected to the photoelectric converter and the sampling circuit, and is used for converting the current signal output by the photoelectric converter into a voltage signal, and sending the voltage signal to the sampling circuit. The current-to-voltage conversion circuit may include a transimpedance amplifier (TIA) that converts the current signal to a voltage signal and may provide gain. The current-to-voltage conversion circuit may also employ capacitors or other types of capacitive-to-voltage conversion devices. The current-to-voltage conversion circuit can also be regarded as a first-stage amplifier.

In some embodiments, the first receiving circuit 120a further includes a current-to-voltage conversion circuit, the current-to-voltage conversion circuit is connected to the first photoelectric converter and the first sampling circuit, and is used for converting the first photoelectric conversion The current signal output by the device is converted into a voltage signal, and the voltage signal is sent to the first sampling circuit.

In some embodiments, the second receiving circuit 120b further includes a current-to-voltage conversion circuit, the current-to-voltage conversion circuit is connected to the second photoelectric converter and the second sampling circuit, and is used for converting the second photoelectric conversion The current signal output by the device is converted into a voltage signal, and the voltage signal is sent to the second sampling circuit.

In some embodiments, the transimpedance amplifier can also be used to implement the function of circuit gating, that is, used to turn on the receiving circuit including the transimpedance amplifier, or turn off the receiving circuit including the transimpedance amplifier. In other embodiments, the gating of the receiving circuit can also be realized by a switch, that is, the distance measuring apparatus 100 further includes a switch connected to each receiving circuit 120, and the switch is used to turn on the receiving circuit connected to it, or turn off the receiving circuit connected to it. connected receiver circuit.

In some embodiments, the structures of the first sampling circuit and the second sampling circuit may be the same or different, and the first sampling circuit and the second sampling circuit are used for sampling the electrical signal. The sampling signals output by the first sampling circuit and the second sampling circuit are passed to the processing module, and the processing module can determine the size of the optical signal according to the sampling signal, and then determine whether to perform ranging according to the first optical signal. As an example, the first sampling circuit and the second sampling circuit include at least the following two implementations:

As an implementation manner, the sampling circuit includes a comparator (for example, an analog comparator (COMP) for converting an electrical signal into a digital signal) and a Time-to-Data Converter (TDC) ), the electrical signal amplified by the primary or secondary amplifying circuit enters the time measurement circuit after passing through the comparator, and the time measurement circuit measures the time difference between the transmission and reception of the laser pulse sequence.

Among them, TDC can be an independent TDC chip, or based on Field-Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC) or Complex Programmable Logic The internal delay chain of programmable devices such as Device and CPLD realizes the TDC circuit of time measurement, or the circuit structure of time measurement is realized by using a high-frequency clock or the circuit structure of time measurement is realized by counting method.

Exemplarily, the first input terminal of the comparator is used for receiving an electrical signal input from the amplifying circuit, the second input terminal is used for receiving a preset threshold value, and a comparison operation is performed between the electrical signal input to the comparator and the preset threshold value. The output signal of the comparator enters the TDC, and the TDC can measure the time information of the edge of the output signal of the comparator. The measured time is based on the laser emission signal as a reference, that is, the time difference between the transmission and reception of the laser signal can be measured.

As another implementation manner, the sampling circuit includes an analog-to-digital converter (Analog-to-Digital Converter, ADC). After the analog signal input to the sampling circuit undergoes analog-to-digital conversion by the ADC, a digital signal can be output to the operation circuit. Likewise, the ADC may be an independent ADC chip, or an ADC circuit implemented based on a programmable device such as a Field-Programmable Gate Array (FPGA).

In some embodiments, each receiving circuit (eg, the first receiving circuit or the second receiving circuit) may also include at least one signal amplifier (AMP), respectively, which may be connected after the transimpedance amplifier, and is used to detect the signal from the transimpedance amplifier. The electrical signal of the resistive amplifier further provides gain to amplify the weak signal output by the transimpedance amplifier to a voltage that the comparator can recognize.

Exemplarily, in addition to the first receiving circuit and the second receiving circuit that are turned on within the current time range, the receiving circuit further includes at least one third receiving circuit that is turned off within the current time range, and each third receiving circuit is associated with a first receiving circuit. Three light emitters correspond. The third receiving circuit may include a third photoelectric converter.

In some embodiments, each receiving circuit is connected to one sampling circuit, that is, the first receiving circuit is connected to the first sampling circuit, each second receiving circuit is connected to each second sampling circuit, and each third receiving circuit is respectively connected In each third sampling circuit, each receiving circuit and sampling circuit operate independently, and the crosstalk is small. FIG. 4 shows an exemplary circuit structure adopting this scheme. In the circuit structure shown in FIG. 4 , the first receiving circuit 410, the second receiving circuit 420 and the at least two third receiving circuits 430 all include a photoelectric receiver, a transimpedance amplifier (TIA) and a secondary amplifier (AMP), And each secondary amplifier is connected with a sampling circuit.

In other embodiments, since the first receiving circuit and the second receiving circuit are turned on at the same time, the remaining multiple third receiving circuits are turned off, so the sampling circuits can also be multiplexed between some receiving circuits that are not turned on within the same time range. , thereby reducing hardware cost and power consumption. Exemplarily, the first receiving circuit and the at least one third receiving circuit may multiplex the same first sampling circuit, and the second receiving circuit and the remaining at least one third receiving circuit may multiplex the same second sampling circuit. Since the first receiving circuit and the second receiving circuit are turned on at the same time, the first receiving circuit and the second receiving circuit do not multiplex the same sampling circuit with the same third receiving circuit.

In addition, if the receiving circuit includes more than two second receiving circuits, since the two or more second receiving circuits are turned on in the same time range, the sampling circuit is not multiplexed between each second receiving circuit.

Specifically, as shown in FIG. 5 , in the circuit structure shown in FIG. 5 , the first receiving circuit 510 and the first and third receiving circuits 530 multiplex the same sampling circuit, and the second receiving circuit 520 and the second and third receiving circuits Circuit 540 multiplexes the same sampling circuit. In addition, since the transimpedance amplifier (TIA) can realize the function of circuit gating, each receiving circuit can include a transimpedance amplifier, thereby realizing independent gating of each receiving circuit. Two receiver circuits that multiplex the same sampling circuit can also multiplex the secondary amplifier (AMP) at the same time for further cost savings.

Although the same sampling circuit is multiplexed for every two receiving circuits in the circuit structure shown in FIG. 5 , in other examples, since there are multiple third receiving circuits that are not turned on in the current time range in the same time range, three One or more than three receiving circuits can also multiplex the same sampling circuit, that is, the first receiving circuit can multiplex the same sampling circuit with two or more third receiving circuits, and the second receiving circuit and the other two Or two or more third receiving circuits multiplex the same sampling circuit, it only needs to ensure that the first receiving circuit and the second receiving circuit that are simultaneously turned on within the same time range do not multiplex the same sampling circuit.

It should be noted that, in this embodiment of the present invention, the multiplexing conditions can be combined and transformed at will, and whether multiplexing and which circuits are multiplexed can be determined according to actual needs. In the case of multiplexing, any of the above combinations falls within the protection scope of the present invention.

As described above, in this embodiment of the present invention, the intensity of the second optical signal is used as a reference to determine whether the first optical signal is noise, and when the intensities of the first optical signal and the second optical signal are similar, the first optical signal is considered to be for noise. However, when the distance between the first photoelectric converter receiving the first optical signal and the second photoelectric converter receiving the second optical signal is too far, it may cause that although the first optical signal and the second optical signal are both floodlight, the intensities are different. larger, resulting in misjudgment. Thus, in one embodiment, the first photoelectric converter may be disposed adjacent to the second photoelectric converter. That is to say, in each time range, two photoelectric converters arranged adjacently are turned on at the same time to receive optical signals, so that when no echo signal is incident, the first receiving circuit and the second receiving circuit will receive The approximate intensity of the floodlight signal, so as to avoid the occurrence of misjudgment.

Further, in addition to the photoelectric converter, the transimpedance amplifiers connected after the photoelectric converter in the first receiving circuit and the second receiving circuit can also be disposed adjacent to each other, thereby further improving the accuracy of the judgment.

In some embodiments, the distance between the first photoelectric converter and the second photoelectric converter can be set within a certain range, so as to ensure that the first photoelectric converter and the second photoelectric converter can receive similar floodlight Signal. As an example, the distance between the first photoelectric converter and the second photoelectric converter is between 0.3 mm and 2 mm, for example, the distance between the two may be set to be about 0.5 mm, within which the first photoelectric converter and the The intensity of the flood light signal received by the second photoelectric converter is similar. When the distance between the first photoelectric converter and the second photoelectric converter is within the above-mentioned certain range, the first photoelectric converter and the second photoelectric converter may be arranged adjacent to each other, or may be arranged at intervals.

In one embodiment, the first photoelectric converter of the first receiving circuit that multiplexes the same first sampling circuit and the third photoelectric converter of the third receiving circuit are arranged at intervals, and the second receiving circuit of the same second sampling circuit is multiplexed. The second photoelectric converter of the circuit and the third photoelectric converter of the third receiving circuit are arranged at intervals, thereby reducing crosstalk between the circuits. For example, referring to FIG. 5 , the first receiving circuit 510 and the first and third receiving circuits 530 multiplex the same sampling circuit, then the first photoelectric converter of the first receiving circuit 510 and the third photoelectric converter of the first and third receiving circuits 530 The converters are set at intervals; the second receiving circuit 520 and the second and third receiving circuits 540 multiplex the same sampling circuit, then the second photoelectric converter of the second receiving circuit 520 and the third photoelectric conversion of the second and third receiving circuits 540 interval setting.

Further, a second photoelectric converter of the second receiving circuit is arranged between the first photoelectric converter of the first receiving circuit of the same first sampling circuit and the third photoelectric converter of the third receiving circuit, that is, by The second photoelectric converter separates the first photoelectric converter and the third photoelectric converter. Continuing to refer to FIG. 5 , a second photoelectric converter of the second receiving circuit 520 is disposed between the first photoelectric converter of the first receiving circuit 510 and the third photoelectric converter of the first and third receiving circuits 530 .

The distance measuring device 100 further includes an optical system including an optical path changing element for changing the optical path of an optical signal incident thereon so that the optical signal is received by the photoelectric converter.

As an example, the optical path changing element may include a lens group disposed in front of the photoelectric converter. According to the environmental conditions of use, the lens group can be designed to be composed of a single lens or multiple lenses. The lens surface type is spherical, aspherical, or a combination of spherical and aspherical surfaces. The lens material of the lens can include glass, plastic, or a combination of glass and plastic. , which is not limited in this embodiment of the present invention. Exemplarily, the lens group structure can be designed with sufficient athermalization to compensate for the influence of temperature drift on imaging.

In some embodiments, the light pulse signal emitted by the light transmitter covers a certain field of view, and the echo signal returned from the field of view is condensed by the light path changing element to the photoelectric converter corresponding to the light transmitter. Since the first receiving circuit and the second receiving circuit are turned on at the same time in the embodiment of the present invention, in order to avoid the difficulty in comparing the echo signals received by the second receiving circuit and the first receiving circuit at the same time, preferably, the optical path changing element can be designed as The echo signals are concentrated within a range smaller than the size of the photoelectric converter, so as to avoid crosstalk when two adjacent photoelectric converters are turned on at the same time.

As an example, the first receiving circuit includes a first photoelectric converter, the second receiving circuit includes a second photoelectric converter, and the ratio of the distance between the first photoelectric converter and the second photoelectric converter to the focal length of the optical path changing element It is not greater than 1/6, so that the first photoelectric converter and the second photoelectric converter can receive similar floodlight signals, and the optical path changing element can also ensure that the echo signal is concentrated on the first photoelectric converter.

In some embodiments, the optical system includes an optical path changing element for changing the optical path of an optical signal incident thereon such that the optical signal is received by the first receiving circuit, wherein the optical path changing element has The focal length is between 28 millimeters and 32 millimeters, and an optical path changing element with this focal length range can better implement the above-mentioned functions of the optical path changing element in the embodiment of the present invention. Illustratively, the focal length of the optical path changing element may be set to about 30 mm.

If the processing module 130 determines that the first optical signal is not noise, the distance information of the object to be measured can be calculated according to the time difference from transmission to reception of the first optical signal and the laser transmission rate. Afterwards, the processing module 130 may also generate images and the like according to the calculated information, which is not limited herein. The distance and orientation detected by the ranging device 100 can be used for remote sensing, obstacle avoidance, mapping, modeling, navigation, and the like.

In some implementations, in addition to the circuit shown in FIG. 1 , the distance measuring device 100 may further include a scanning module for changing the propagation direction of at least one optical pulse sequence (eg, a laser pulse sequence) output from the transmitting circuit to output the field of view. to scan. Exemplarily, the scanning area of the scanning module within the field of view of the ranging device increases over time.

The module including the optical transmitter 110, the receiving circuit 120 and the processing module 130 may be referred to as a ranging module, and the ranging module may be independent of other modules, for example, a scanning module.

A coaxial optical path may be used in the ranging device, that is, the light beam emitted by the ranging device and the reflected light beam share at least part of the optical path in the ranging device. For example, after at least one laser pulse sequence emitted by the transmitting circuit changes its propagation direction through the scanning module, the laser pulse sequence reflected by the detection object passes through the scanning module and then enters the receiving circuit. Alternatively, the distance-measuring device may also adopt an off-axis optical path, that is, the light beam emitted by the distance-measuring device and the reflected light beam are respectively transmitted along different optical paths in the distance-measuring device. FIG. 2 is a schematic diagram showing an example of a coaxial optical path used by the distance measuring device according to the embodiment of the present invention.

As shown in FIG. 2 , the ranging device 200 includes a ranging module 210, and the ranging module 210 includes a transmitter 203 (which may include the above-mentioned transmitting circuit), a collimating element 204, and a photoelectric converter 205 (which may include the above-mentioned receiving circuit, sampling circuit and arithmetic circuit) and an optical path changing element 206. The ranging module 210 is used for emitting a light beam, receiving the returning light, and converting the returning light into an electrical signal. Among them, the transmitter 203 can be used to transmit a sequence of optical pulses. In one embodiment, the transmitter 203 may emit a sequence of laser pulses. Optionally, the laser beam emitted by the transmitter 203 is a narrow bandwidth beam with a wavelength outside the visible light range. The collimating element 204 is disposed on the outgoing light path of the transmitter, and is used for collimating the light beam emitted from the transmitter 203, and collimating the light beam emitted by the transmitter 203 into parallel light and outputting to the scanning module. The collimating element also serves to converge at least a portion of the return light reflected by the probe. The collimating element 204 may be a collimating lens or other elements capable of collimating light beams.

In the embodiment shown in FIG. 2, the transmitting optical path and the receiving optical path in the ranging device are combined by the optical path changing element 206 before the collimating element 204, so that the transmitting optical path and the receiving optical path can share the same collimating element, so that the optical path more compact. In some other implementations, the emitter 203 and the photoelectric converter 205 may use their own collimating elements, respectively, and the optical path changing element 206 may be disposed on the optical path behind the collimating elements.

In the embodiment shown in FIG. 2 , since the beam aperture of the beam emitted by the transmitter 203 is small, and the beam aperture of the return light received by the ranging device is relatively large, the optical path changing element can use a small-area reflective mirror to The transmit light path and the receive light path are combined. In some other implementations, the optical path changing element can also use a reflector with a through hole, wherein the through hole is used to transmit the outgoing light of the emitter 203 , and the reflector is used to reflect the returned light to the photoelectric converter 205 . In this way, in the case of using a small reflector, the occlusion of the return light by the support of the small reflector can be reduced.

In the embodiment shown in FIG. 2 , the optical path altering element is offset from the optical axis of the collimating element 204 . In some other implementations, the optical path altering element may also be located on the optical axis of the collimating element 204 .

The ranging device 200 further includes a scanning module 202 . The scanning module 202 is placed on the outgoing optical path of the ranging module 210 . The scanning module 202 is used to change the transmission direction of the collimated beam 219 emitted by the collimating element 204 and project it to the external environment, and project the return light to the collimating element 204 . The returned light is collected on the photoelectric converter 205 through the collimating element 204 .

In one embodiment, the scanning module 202 can include at least one optical element for changing the propagation path of the light beam, wherein the optical element can change the propagation path of the light beam by reflecting, refracting, diffracting the light beam, etc. The optical element includes at least one light-refractive element having non-parallel exit and entrance surfaces. For example, the scanning module 202 includes lenses, mirrors, prisms, galvanometers, gratings, liquid crystals, optical phased arrays (Optical Phased Array) or any combination of the above optical elements. In one example, at least part of the optical elements are moving, for example, the at least part of the optical elements are driven to move by a driving module, and the moving optical elements can reflect, refract or diffract the light beam to different directions at different times. In some embodiments, the multiple optical elements of the scanning module 202 may be rotated or oscillated about a common axis 209, each rotating or oscillating optical element being used to continuously change the propagation direction of the incident beam. In one embodiment, the plurality of optical elements of the scanning module 202 may rotate at different rotational speeds, or vibrate at different speeds. In another embodiment, at least some of the optical elements of scan module 202 may rotate at substantially the same rotational speed. In some embodiments, the plurality of optical elements of the scanning module may also be rotated about different axes. In some embodiments, the plurality of optical elements of the scanning module may also rotate in the same direction, or rotate in different directions; or vibrate in the same direction, or vibrate in different directions, which are not limited herein.

In one embodiment, the scanning module 202 includes a first optical element 214 and a driver 216 connected to the first optical element 214, and the driver 216 is used to drive the first optical element 214 to rotate around the rotation axis 209, so that the first optical element 214 changes The direction of the collimated beam 219. The first optical element 214 projects the collimated beam 219 in different directions. In one embodiment, the angle between the direction of the collimated light beam 219 changed by the first optical element and the rotation axis 209 changes with the rotation of the first optical element 214 . In one embodiment, the first optical element 214 includes a pair of opposing non-parallel surfaces through which the collimated beam 219 passes. In one embodiment, the first optical element 214 includes a prism whose thickness varies along at least one radial direction. In one embodiment, the first optical element 214 includes a wedge prism that refracts the collimated light beam 219 .

In one embodiment, the scanning module 202 further includes a second optical element 215 , the second optical element 215 rotates around the rotation axis 209 , and the rotation speed of the second optical element 215 is different from the rotation speed of the first optical element 214 . The second optical element 215 is used to change the direction of the light beam projected by the first optical element 214 . In one embodiment, the second optical element 215 is connected to another driver 217, and the driver 217 drives the second optical element 215 to rotate. The first optical element 214 and the second optical element 215 can be driven by the same or different drivers, so that the rotational speed and/or steering of the first optical element 214 and the second optical element 215 are different, thereby projecting the collimated beam 219 into the external space Different directions can scan a larger spatial range. In one embodiment, the controller 218 controls the driver 216 and the driver 217 to drive the first optical element 214 and the second optical element 215, respectively. The rotational speeds of the first optical element 214 and the second optical element 215 may be determined according to the area and pattern expected to be scanned in practical applications.

Drivers

216 and 217 may include motors or other drivers.

In one embodiment, the second optical element 215 includes a pair of opposing non-parallel surfaces through which the light beam passes. In one embodiment, the second optical element 215 comprises a prism whose thickness varies along at least one radial direction. In one embodiment, the second optical element 215 comprises a wedge prism.

In one embodiment, the scanning module 202 further includes a third optical element (not shown) and a driver for driving the movement of the third optical element. Optionally, the third optical element includes a pair of opposing non-parallel surfaces through which the light beam passes. In one embodiment, the third optical element comprises a prism of varying thickness along at least one radial direction. In one embodiment, the third optical element comprises a wedge prism. At least two of the first, second and third optical elements rotate at different rotational speeds and/or rotations.

In one embodiment, the scanning module includes two or three of the light refraction elements sequentially arranged on the outgoing light path of the light pulse sequence. Optionally, at least two of the light refraction elements in the scanning module are rotated during the scanning process to change the direction of the light pulse sequence.

The scanning paths of the scanning module are different at least at some different times. The rotation of each optical element in the scanning module 202 can project light in different directions, such as the direction of the projected light 211 and the direction 213 . space to scan. When the light 211 projected by the scanning module 202 hits the detected object 201 , a part of the light is reflected by the detected object 201 to the distance measuring device 200 in a direction opposite to the projected light 211 . The returning light 212 reflected by the probe 201 passes through the scanning module 202 and then enters the collimating element 204 .

The photoelectric converter 205 is placed on the same side of the collimating element 204 as the transmitter 203, and the photoelectric converter 205 is used to convert at least part of the return light passing through the collimating element 204 into an electrical signal.

In one embodiment, each optical element is coated with an anti-reflection coating. Optionally, the thickness of the anti-reflection film is equal to or close to the wavelength of the light beam emitted by the emitter 203, which can increase the intensity of the transmitted light beam.

In one embodiment, a filter layer is coated on the surface of an element located on the beam propagation path in the distance measuring device, or a filter is provided on the beam propagation path for transmitting at least the wavelength band of the light beam emitted by the transmitter, Reflects other bands to reduce noise from ambient light to the receiver.

In some embodiments, the transmitter 203 may comprise a laser diode through which laser pulses are emitted on the nanosecond scale. Further, the laser pulse receiving time can be determined, for example, by detecting the rising edge time and/or the falling edge time of the electrical signal pulse to determine the laser pulse receiving time. In this way, the distance measuring device 200 can calculate the TOF 207 by using the pulse receiving time information and the pulse sending time information, so as to determine the distance from the probe 201 to the distance measuring device 200 . The distance and orientation detected by the ranging device 200 can be used for remote sensing, obstacle avoidance, mapping, modeling, navigation, and the like.

To sum up, according to the distance measuring device 100 according to the embodiment of the present invention, in the time range when the currently turned on optical transmitter transmits the optical pulse signal, in addition to turning on the first receiving circuit corresponding to the currently turned on optical transmitter, also At the same time, the second receiving circuit is turned on, and the optical signals received by the first receiving circuit and the second receiving circuit are compared to determine whether the first receiving circuit receives noise, thereby improving the anti-interference performance of the ranging device.

Another aspect of the embodiments of the present invention provides a ranging method. FIG. 6 shows a flowchart of a ranging method 600 . The ranging method 600 may be implemented by the ranging apparatus described in any of the above embodiments. Only the main steps of the ranging method 600 will be described below, and some of the above detailed details will be omitted.

As shown in FIG. 6 , the ranging method 600 includes the following steps:

In step S610, turn on the light transmitter to transmit the light pulse signal;

In step S620, the first receiving circuit and the second receiving circuit are simultaneously turned on, and the first receiving circuit receives at least part of the echo signal of the optical pulse signal after being converged by the optical system;

In step S630, it is determined whether the first optical signal is noise according to the intensities of the first optical signal and the second optical signal, wherein the first optical signal and the second optical signal are the first receiving circuit respectively and the optical signal received by the second receiving circuit in the same time period.

As an example, in step S630, the determining whether the first optical signal is noise according to the intensities of the first optical signal and the second optical signal includes:

If the ratio of the intensity of the first optical signal to the second optical signal is less than or equal to a first threshold, it is determined that the first optical signal is noise.

As an example, the value range of the first threshold is (0, 3].

If the intensity ratio of the first optical signal and the second optical signal is between a second threshold and a third threshold, it is determined that the first optical signal is not noise, wherein the second threshold is smaller than the first threshold Three thresholds.

Wherein, the second threshold is greater than the first threshold.

If the ratio of the first optical signal to the second optical signal is greater than or equal to a fourth threshold, it is determined that the first optical signal is noise. Wherein, the third threshold is smaller than the fourth threshold, and the fourth threshold may be determined according to the intensity of the optical pulse signal emitted by each optical transmitter.

In one embodiment, the first receiving circuit includes a first photoelectric converter, and the method includes receiving an optical signal through the first photoelectric converter, and converting the optical signal into an electrical signal; the ranging The device further includes a first sampling circuit, the first sampling circuit is connected to the first receiving circuit and the processing module, and the method further includes sampling the electrical signal through the first sampling circuit to obtain A sampled signal is sent, and the sampled signal is sent to the processing module, and the processing module determines the intensity of the optical signal according to the sampled signal.

In one embodiment, the first receiving circuit further includes a current-voltage conversion circuit, and the method further includes converting the current signal output by the first photoelectric converter into a voltage signal through the current-voltage conversion circuit, and converting The voltage signal is sent to the first sampling circuit, and the current-to-voltage conversion circuit is connected to the first photoelectric converter and the first sampling circuit.

In one embodiment, the second receiving circuit includes a second photoelectric converter, and the method further includes receiving an optical signal through the second photoelectric converter, and converting the optical signal into an electrical signal; the measuring The distance device further includes a second sampling circuit, the second sampling circuit is connected to the second receiving circuit and the processing module, and the method further includes using the second sampling circuit to output an output signal of the second receiving circuit. The electrical signal is sampled to obtain a sampled signal, and the sampled signal is sent to the processing module, and the processing module determines the intensity of the optical signal according to the sampled signal.

In one embodiment, the second receiving circuit further includes a current-to-voltage conversion circuit, the current-to-voltage conversion circuit is connected to the second photoelectric converter and the second sampling circuit, and the method further includes using the The current-voltage conversion circuit converts the current signal output by the second photoelectric converter into a voltage signal, and sends the voltage signal to the second sampling circuit.

In one embodiment, each of the receiving circuits includes an optoelectronic converter, and the ranging method 600 includes receiving an optical signal through the optoelectronic converter, and converting the optical signal into an electrical signal, the optoelectronic converter including the optoelectronic converter. The first photoelectric converter in the first receiving circuit and the second photoelectric converter in the second receiving circuit; the ranging method 600 further includes sampling the electrical signal through a sampling circuit to obtain a sampling signal, and Send the sampling signal to the processing module, the processing module determines the strength of the optical signal according to the sampling signal, the sampling circuit is respectively connected with the receiving circuit and the processing module, the sampling circuit It includes a first sampling circuit connected to the first receiving circuit and a second sampling circuit connected to the second receiving circuit.

In one embodiment, the ranging method 600 further includes converting the current signal output by the photoelectric converter into a voltage signal through a current-voltage converting circuit in the receiving circuit, and sending the voltage signal to the sampling circuit , the current-voltage conversion circuit is connected with the photoelectric converter and the sampling circuit.

In one embodiment, the current-voltage conversion circuit includes a transimpedance amplifier, and the ranging method 600 includes turning on a receiving circuit including the transimpedance amplifier through the transimpedance amplifier, or turning off the receiving circuit including the transimpedance amplifier .

In one embodiment, the receiving circuit includes more than two second receiving circuits, and each of the second receiving circuits multiplexes one of the second sampling circuits. Further, the receiving circuit may further include a third receiving circuit, and the third receiving circuit is turned off at the same time period when the first receiving circuit and the second receiving circuit are turned on. Further, there are at least two third receiving circuits, the first receiving circuit and at least one third receiving circuit multiplex the same first sampling circuit, and/or, the second receiving circuit and the other at least one third receiving circuit The receiving circuit multiplexes the same second sampling circuit.

Exemplarily, the first photoelectric converter is disposed adjacent to the second photoelectric converter. In one embodiment, the photoelectric converters of the first receiving circuit and the third receiving circuit that multiplex the same first sampling circuit are arranged at intervals, and the second receiving circuit and the third receiving circuit of the same second sampling circuit are multiplexed. The photoelectric converters are arranged at intervals. For example, the photoelectric converter of the second receiving circuit is provided between the first receiving circuit of the first sampling circuit and the photoelectric converter of the third receiving circuit that are multiplexed.

In one embodiment, the receiving circuit is connected to a switch, and the ranging method 600 further includes turning on the receiving circuit connected to the switch through the switch, or turning off the receiving circuit connected to the switch.

In one embodiment, the first receiving circuit includes a first photoelectric converter, the second receiving circuit includes a second photoelectric converter, and the first photoelectric converter and the second photoelectric converter are used for receiving optical The optical system includes an optical path changing element, and the ranging method 600 includes changing the optical path of an optical signal incident thereon by the optical path changing element, so that the optical signal is received by the photoelectric converter; wherein, the first The ratio of the distance between the first photoelectric converter and the second photoelectric converter to the focal length of the optical path changing element is not greater than 1/6.

Exemplarily, the optical system includes an optical path changing element for changing the optical path of an optical signal incident thereon so that the optical signal is received by the first receiving circuit, wherein the optical path changes The focal length of the element is between 28mm and 32mm.

Exemplarily, the first receiving circuit includes a first photoelectric converter, the second receiving circuit includes a second photoelectric converter, and the first photoelectric converter and the second photoelectric converter are used for receiving optical signals, Wherein, the distance between the first photoelectric converter and the second photoelectric converter is between 0.3 mm and 2 mm.

In one embodiment, the method further includes receiving optical signals through at least three photoelectric converters, and converting the optical signals into electrical signals, wherein at least some of the photoelectric converters are arranged at equal intervals, and/ Or, at least some of the photoelectric converters are arranged at unequal intervals.

Exemplarily, the directions of the optical pulse signals emitted by different optical transmitters are the same or different. Multiple light emitters are packaged together or individually.

In one embodiment, if it is determined that the first optical signal is noise, the ranging method 600 further includes: filtering out the first optical signal. If it is determined that the first optical signal is not noise, the ranging method 600 may further include performing ranging according to the first optical signal based on methods such as time of flight of light or based on phase shift.

According to the ranging method 600 according to the embodiment of the present invention, within the time range of the optical pulse signal emitted by the optical transmitter currently turned on, in addition to turning on the first receiving circuit corresponding to the optical transmitter currently turned on, the second receiving circuit is also turned on at the same time circuit, and compares the optical signals received by the first receiving circuit and the second receiving circuit to determine whether the first receiving circuit receives noise or not, thereby improving the accuracy of the ranging method.

An embodiment of the present invention further provides a movable platform, the movable platform includes any of the above distance measuring devices and a movable platform body, and the distance measuring device is mounted on the movable platform body. In some embodiments, the movable platform may operate fully autonomously or semi-autonomously. In some embodiments, the movable platform can operate either semi-autonomously in response to one or more commands from a remote control, or fully autonomously following preset program instructions.

Further, the movable platform includes but is not limited to at least one of a car, a remote control car, an aircraft, and a robot. The vehicle may be an autonomous vehicle or a semi-autonomous vehicle, and the aircraft may be an unmanned aerial vehicle, such as a fixed-wing drone, a rotary-wing drone, and the like. When the movable platform is an aircraft, the movable platform body is the fuselage of the aircraft. When the movable platform is an automobile, the movable platform body is the body of the automobile. When the movable platform is a remote control car, the movable platform body is the body of the remote control car. When the movable platform is a robot, the platform body is the body of the robot.

The movable platform can control the movement of the movable platform body according to the distance measurement result of the distance measuring device. For example, in the road scene, after the distance measuring device obtains the point cloud data, the movable platform can predict the relevant attributes of the obstacles according to the point cloud data, realize the detection and segmentation of the foreground obstacles, and then predict the trajectory of the obstacles, as a The judgment basis for driving planning; it can also detect the passable space according to the point cloud height and continuity information of drivable roads and intersections, etc., or can use the point cloud information to match with high-precision maps to achieve high-precision positioning .

Since the distance measuring device of the embodiment of the present invention has high anti-interference performance, the movable platform using the above distance measuring device also has similar advantages.

Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above-described example embodiments are exemplary only, and are not intended to limit the scope of the invention thereto. Various changes and modifications can be made therein by those of ordinary skill in the art without departing from the scope and spirit of the invention. All such changes and modifications are intended to be included within the scope of the invention as claimed in the appended claims.

Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of the present invention.

In the several embodiments provided in this application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or May be integrated into another device, or some features may be omitted, or not implemented.

In the description provided herein, numerous specific details are set forth. It will be understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Similarly, it is to be understood that in the description of the exemplary embodiments of the invention, various features of the invention are sometimes grouped together , or in its description. However, this method of the invention should not be interpreted as reflecting the intention that the invention as claimed requires more features than are expressly recited in each claim. Rather, as the corresponding claims reflect, the invention lies in the fact that the corresponding technical problem may be solved with less than all features of a single disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.

It will be understood by those skilled in the art that all features disclosed in this specification (including the accompanying claims, abstract and drawings) and any method or apparatus so disclosed may be used in any combination, except that the features are mutually exclusive. Processes or units are combined. Each feature disclosed in this specification (including accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

Furthermore, those skilled in the art will appreciate that although some of the embodiments described herein include certain features, but not others, included in other embodiments, that combinations of features of different embodiments are intended to be within the scope of the invention within and form different embodiments. For example, in the claims, any of the claimed embodiments may be used in any combination.

Various component embodiments of the present invention may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art should understand that a microprocessor or a digital signal processor (DSP) may be used in practice to implement some or all of the functions of some modules according to the embodiments of the present invention. The present invention may also be implemented as apparatus programs (eg, computer programs and computer program products) for performing part or all of the methods described herein. Such a program implementing the present invention may be stored on a computer-readable medium, or may be in the form of one or more signals. Such signals may be downloaded from Internet sites, or provided on carrier signals, or in any other form.

It should be noted that the above-described embodiments illustrate rather than limit the invention, and that alternative embodiments may be devised by those skilled in the art without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The use of the words first, second, and third, etc. do not denote any order. These words can be interpreted as names.

Claims

A distance measuring device, characterized in that the distance measuring device comprises: an optical transmitter, an optical system, a first receiving circuit, a second receiving circuit, and a processing module,

The optical transmitter is used for sequentially transmitting optical pulse signals; at least part of the echo signals of the optical pulse signals reflected by the object are collected by the optical system and then received by the first receiving circuit;

The second receiving circuit and the first receiving circuit are turned on at the same time, and the optical signals received by the first receiving circuit and the second receiving circuit in the same period are the first optical signal and the second optical signal respectively;

The processing module is configured to determine whether the first optical signal is noise according to the intensities of the first optical signal and the second optical signal.
The distance measuring device according to claim 1, wherein the determining whether the first optical signal is noise according to the intensities of the first optical signal and the second optical signal comprises:

If the ratio of the intensity of the first optical signal to the second optical signal is less than or equal to a first threshold, the first optical signal is noise.
The distance measuring device according to claim 2, wherein the value range of the first threshold is (0, 3].
The distance measuring device according to any one of claims 1-3, wherein the determining whether the first optical signal is noise according to the intensities of the first optical signal and the second optical signal comprises:

If the intensity ratio of the first optical signal to the second optical signal is between a second threshold and a third threshold, the first optical signal is not noise, wherein the second threshold is smaller than the third threshold threshold.
The distance measuring device according to claim 4, wherein the second threshold is greater than the first threshold.
The distance measuring device according to any one of claims 1-5, wherein the determining whether the first optical signal is noise according to the intensities of the first optical signal and the second optical signal comprises:

If the ratio of the first optical signal to the second optical signal is greater than or equal to a fourth threshold, the first optical signal is noise.
The distance measuring device according to claim 6, wherein the third threshold is smaller than the fourth threshold.
The distance measuring device according to claim 6, wherein the fourth threshold is determined according to the intensity of the optical pulse signal emitted by each of the optical transmitters.
The distance measuring device according to claim 1, wherein the first receiving circuit comprises a first photoelectric converter for receiving an optical signal and converting the optical signal into an electrical signal;

The distance measuring device further includes a first sampling circuit, the first sampling circuit is connected to the first receiving circuit and the processing module, and is used for sampling the electrical signal output by the first receiving circuit to obtain A sampled signal is sent, and the sampled signal is sent to the processing module, and the processing module determines the intensity of the optical signal according to the sampled signal.
The distance measuring device according to claim 9, wherein the first receiving circuit further comprises a current-to-voltage conversion circuit, and the current-to-voltage conversion circuit is connected to the first photoelectric converter and the first sampling circuit , for converting the current signal output by the first photoelectric converter into a voltage signal, and sending the voltage signal to the first sampling circuit.
The distance measuring device according to any one of claims 1-10, wherein the second receiving circuit comprises a second photoelectric converter for receiving an optical signal and converting the optical signal into an electrical signal;

The distance measuring device further includes a second sampling circuit, which is connected to the second receiving circuit and the processing module, and is used for sampling the electrical signal output by the second receiving circuit to obtain sampling a signal, and sending the sampling signal to the processing module, and the processing module determines the intensity of the optical signal according to the sampling signal;

The second receiving circuit further includes a current-voltage conversion circuit, which is connected to the second photoelectric converter and the second sampling circuit, and is used to convert the current signal output by the second photoelectric converter Converting into a voltage signal, and sending the voltage signal to the second sampling circuit.
The distance measuring device according to claim 10 or 11, wherein the current-voltage conversion circuit comprises a transimpedance amplifier, and the transimpedance amplifier is further configured to turn on a receiving circuit comprising the transimpedance amplifier, or turn off a receiving circuit comprising the transimpedance amplifier the receiver circuit of the transimpedance amplifier.
The ranging device according to any one of claims 1-12, characterized in that, the ranging device further comprises a third receiving circuit, and the third receiving circuit is connected between the first receiving circuit and the second receiving circuit. The receiving circuit is turned off during the same period of time.
The distance measuring device according to claim 13, wherein there are at least two third receiving circuits, and the first receiving circuit and at least one third receiving circuit multiplex the same first sample circuit, and/or, the second receiving circuit and the other at least one third receiving circuit multiplex the same second sampling circuit.
The distance measuring device according to claim 13 or 14, wherein the first photoelectric converter is disposed adjacent to the second photoelectric converter.
The distance measuring device according to claim 15, wherein the photoelectric converters connected to the first receiving circuit and the third receiving circuit of the same first sampling circuit are arranged at intervals, and are connected to the same one The second receiving circuit of the second sampling circuit and the photoelectric converter of the third receiving circuit are arranged at intervals.
The distance measuring device according to claim 16, wherein the photoelectric converters connected to the first receiving circuit and the third receiving circuit of the same first sampling circuit are arranged at intervals, comprising: :

The photoelectric converter of the second receiving circuit is arranged between the first receiving circuit of the same first sampling circuit and the photoelectric converter of the third receiving circuit.
The distance measuring device according to claim 1, further comprising a switch connected to the receiving circuit, wherein the switch is used to turn on the receiving circuit connected to the switch, or close the receiving circuit connected to the switch .
The distance measuring device according to claim 1, wherein the first receiving circuit comprises a first photoelectric converter, the second receiving circuit comprises a second photoelectric converter, the first photoelectric converter and the The second photoelectric converter is used for receiving an optical signal; the optical system includes an optical path changing element for changing the optical path of the optical signal incident thereon, so that the optical signal is changed by the first photoelectric converter receives;

The ratio of the distance between the first photoelectric converter and the second photoelectric converter to the focal length of the optical path changing element is not greater than 1/6.
The distance measuring device according to claim 1, wherein the optical system includes an optical path changing element for changing the optical path of the optical signal incident thereon, so that the optical signal is The first receiving circuit receives, wherein the focal length of the optical path changing element is between 28 mm and 32 mm.
The distance measuring device according to claim 1, wherein the first receiving circuit comprises a first photoelectric converter, the second receiving circuit comprises a second photoelectric converter, the first photoelectric converter and the The second photoelectric converter is used for receiving optical signals, wherein the distance between the first photoelectric converter and the second photoelectric converter is between 0.3 mm and 2 mm.
The distance measuring device according to claim 1, wherein the receiving circuit comprises at least three photoelectric converters for receiving optical signals and converting the optical signals into electrical signals, wherein at least some of the The photoelectric converters are arranged at equal intervals, and/or at least some of the photoelectric converters are arranged at unequal intervals.
The distance measuring device according to claim 1, wherein the directions of the optical pulse signals emitted by different optical transmitters are the same or different.
The distance measuring device according to claim 1, wherein a plurality of the light emitters are packaged together or individually.
The distance measuring device according to any one of claims 1-24, wherein, if it is determined that the first optical signal is noise, the processing module is further configured to filter out the first optical signal.
A ranging method, characterized in that the ranging method comprises:

turn on the light transmitter to emit light pulse signal;

The first receiving circuit and the second receiving circuit are simultaneously turned on, and the first receiving circuit receives at least part of the echo signal of the optical pulse signal after being converged by the optical system;

Whether the first optical signal is noise is determined according to the intensities of the first optical signal and the second optical signal, wherein the first optical signal and the second optical signal are the first receiving circuit and the first receiving circuit, respectively. The optical signals received by the two receiving circuits at the same time period.
The ranging method according to claim 26, wherein the determining whether the first optical signal is noise according to the intensities of the first optical signal and the second optical signal comprises:

If the ratio of the intensity of the first optical signal to the second optical signal is less than or equal to a first threshold, the first optical signal is noise.
The ranging method according to claim 27, wherein the value range of the first threshold is (0, 3].
The distance measuring method according to any one of claims 26-28, wherein the determining whether the first optical signal is noise according to the intensities of the first optical signal and the second optical signal comprises:

If the intensity ratio of the first optical signal to the second optical signal is between a second threshold and a third threshold, the first optical signal is not noise, wherein the second threshold is smaller than the third threshold threshold.
The ranging method according to claim 29, wherein the second threshold is greater than the first threshold.
The distance measuring method according to any one of claims 26-30, wherein the determining whether the first optical signal is noise according to the intensities of the first optical signal and the second optical signal comprises:

If the ratio of the first optical signal to the second optical signal is greater than or equal to a fourth threshold, the first optical signal is noise.
The ranging method according to claim 31, wherein the third threshold is smaller than the fourth threshold.
The ranging method according to claim 31, wherein the fourth threshold is determined according to the intensity of the optical pulse signal emitted by each of the optical transmitters.
The distance measuring method according to claim 26, wherein the first receiving circuit comprises a first photoelectric converter, and the method comprises receiving an optical signal through the first photoelectric converter, and converting the optical signal converted into electrical signals;

The distance measuring device further includes a first sampling circuit, the first sampling circuit is connected to the first receiving circuit and the processing module, and the method further includes performing a sampling on the electrical signal through the first sampling circuit. sampling to obtain a sampling signal, and sending the sampling signal to the processing module, and the processing module determines the intensity of the optical signal according to the sampling signal.
The distance measuring method according to claim 34, wherein the first receiving circuit further comprises a current-voltage conversion circuit, and the method further comprises converting the output of the first photoelectric converter through the current-voltage conversion circuit The current signal is converted into a voltage signal, and the voltage signal is sent to the first sampling circuit, and the current-to-voltage conversion circuit is connected with the first photoelectric converter and the first sampling circuit.
The distance measuring method according to any one of claims 26-35, wherein the second receiving circuit comprises a second photoelectric converter, and the method further comprises receiving an optical signal through the second photoelectric converter, and converting the optical signal into an electrical signal;

The distance measuring device further includes a second sampling circuit, the second sampling circuit is connected to the second receiving circuit and the processing module, and the method further includes using the second sampling circuit to detect the second receiving circuit. The electrical signal output by the circuit is sampled to obtain a sampled signal, and the sampled signal is sent to the processing module, and the processing module determines the intensity of the optical signal according to the sampled signal;

The second receiving circuit further includes a current-to-voltage conversion circuit, the current-to-voltage conversion circuit is connected to the second photoelectric converter and the second sampling circuit, and the method further includes converting the The current signal output by the second photoelectric converter is converted into a voltage signal, and the voltage signal is sent to the second sampling circuit.
The distance measuring method according to claim 35 or 36, wherein the current-voltage conversion circuit comprises a transimpedance amplifier, and the method further comprises turning on a receiving circuit comprising the transimpedance amplifier through the transimpedance amplifier, or turn off the receiving circuit including the transimpedance amplifier.
The distance measuring device according to any one of claims 26 to 37, wherein the distance measuring device further comprises a third receiving circuit, the third receiving circuit is connected between the first receiving circuit and the second receiving circuit. The receiving circuit is turned off during the same period of time.
The ranging method according to claim 38, wherein there are at least two third receiving circuits, and the first receiving circuit and at least one third receiving circuit multiplex the same first sample circuit, and/or, the second receiving circuit and the other at least one third receiving circuit multiplex the same second sampling circuit.
The distance measuring method according to claim 38 or 39, wherein the first photoelectric converter is disposed adjacent to the second photoelectric converter.
The distance measuring method according to claim 40, wherein the photoelectric converters connected to the first receiving circuit and the third receiving circuit of the same first sampling circuit are arranged at intervals, and are connected to the same one The second receiving circuit of the second sampling circuit and the photoelectric converter of the third receiving circuit are arranged at intervals.
The distance measuring method according to claim 41, wherein the photoelectric converters connected to the first receiving circuit and the third receiving circuit of the same first sampling circuit are arranged at intervals, comprising: :

The photoelectric converter of the second receiving circuit is arranged between the first receiving circuit of the same first sampling circuit and the photoelectric converter of the third receiving circuit.
The distance measuring method according to claim 26, wherein the receiving circuit is connected to a switch, and the method further comprises turning on the receiving circuit connected to the switch through the switch, or turning off the receiving circuit connected to the switch. receiving circuit.
The distance measuring method according to claim 26, wherein the first receiving circuit comprises a first photoelectric converter, the second receiving circuit comprises a second photoelectric converter, the first photoelectric converter and the the second photoelectric converter is used for receiving an optical signal; the optical system includes an optical path changing element for changing the optical path of the optical signal incident thereon, so that the optical signal is received by the photoelectric converter;

The ratio of the distance between the first photoelectric converter and the second photoelectric converter to the focal length of the optical path changing element is not greater than 1/6.
The distance measuring method according to claim 26, wherein the optical system includes an optical path changing element for changing the optical path of the optical signal incident thereon, so that the optical signal is The first receiving circuit receives, wherein the focal length of the optical path changing element is between 28 mm and 32 mm.
The distance measuring method according to claim 26, wherein the first receiving circuit comprises a first photoelectric converter, the second receiving circuit comprises a second photoelectric converter, the first photoelectric converter and the The second photoelectric converter is used for receiving optical signals, wherein the distance between the first photoelectric converter and the second photoelectric converter is between 0.3 mm and 2 mm.
The distance measuring method according to claim 26, wherein the receiving circuit comprises at least three photoelectric converters for receiving optical signals and converting the optical signals into electrical signals, wherein at least some of the The photoelectric converters are arranged at equal intervals, and/or at least some of the photoelectric converters are arranged at unequal intervals.
The ranging method according to claim 26, wherein the directions of the optical pulse signals emitted by the different optical transmitters are the same or different.
The ranging method according to claim 26, wherein a plurality of the light emitters are packaged together or individually.
The ranging method according to any one of claims 26-49, wherein the method further comprises: filtering out the first optical signal if it is determined that the first optical signal is noise.
A movable platform, characterized in that, comprising:

Movable platform body;

The distance measuring device according to any one of claims 1-25, wherein the distance measuring device is mounted on the movable platform body.
The movable platform according to claim 51, wherein the movable platform controls the movement of the movable platform body according to the ranging result of the ranging device.
The movable platform of claim 51 , wherein the movable platform comprises at least one of a car, a remote-controlled car, an aircraft, and a robot.