WO2021168866A1

WO2021168866A1 - Anti-interference distance measuring device and method

Info

Publication number: WO2021168866A1
Application number: PCT/CN2020/077360
Authority: WO
Inventors: 罗鹏飞; 董晨; 周鸿彬; 武雪飞; 唐样洋
Original assignee: 华为技术有限公司
Priority date: 2020-02-29
Filing date: 2020-02-29
Publication date: 2021-09-02
Also published as: CN115004054A

Abstract

An anti-interference distance measuring device and method. The device comprises a pulse position modulator (1011) and a phase-shift keying modulator (1012) connected to the pulse position modulator (1011). The pulse position modulator (1011) is used for generating a baseband signal according to a random number signal. Each random number in the random number signal corresponds to the pulse position of a baseband signal. When there is a plurality of consecutive identical random numbers in the random number signal, M time intervals exist between pulse positions corresponding to the plurality of consecutive identical random numbers in the baseband signal. The phase of the random number signal and the phase of the baseband signal are synchronous. The phase-shift keying modulator (1012) is used for modulating a carrier signal and the baseband signal to generate a first signal. The first signal is used for driving a luminescent device (103) to generate a first pulsed light to irradiate an object to be measured. The anti-interference distance measuring device and method can improve the anti-interference capability of a distance measuring signal.

Description

Anti-interference ranging device and method

Technical field

This application relates to the technical field of distance measurement, and in particular to an anti-interference distance measurement device and method.

Background technique

Time of flight imaging (TOF imaging) technology is an active imaging method, that is, the camera system emits laser light to the target object, and the distance to the target is calculated by measuring the time when the sensor receives the reflected light from the target. In the case of using actively modulated light for illumination, in order to obtain higher measurement accuracy and resolution, it is necessary to reduce the influence of noise and interference on the output result.

In the process of using TOF cameras, it is inevitable that there will be scenes where multiple cameras take pictures of the same object together or multiple cameras take pictures of each other. If no processing is done, the calculated distance and the true distance will basically not be equal. In TOF applications, there is a situation where multiple machines work together, and traditional continuous wave modulation or pulse wave modulation is easily interfered by multiple machines at the same frequency, resulting in errors in the ranging results.

Currently, Code Division Multiplexing (CDM) and Binary Phase Shift Keying (BPSK) technologies are used to generate random phase hopping square wave signals. Pixel modulation signals are sent in groups, and the waveform frequency between each group is fixed, but the phase is only 0 degrees and 180 degrees, and there is no gap time. Among them, the phase of the random jump is controlled by any kind of pseudo-random number or a binary random number generated by a random number generator (for example, binary 0 corresponds to a phase of 0 degrees, and binary 1 corresponds to a phase of 180 degrees). But when the exposure time is constant and the working frequency is too high, the random number sequence may be too long, and there will be a long continuous 0 or continuous 1 in the too long random number sequence, and the possibility of interference with such a long continuous signal will be Greatly increase, affecting the anti-jamming effect.

Therefore, how to improve the anti-interference ability of imaging in the case of multiple TOF cameras for distance measurement is a problem to be solved urgently.

Summary of the invention

The embodiments of the present application provide an anti-interference ranging device and method, which can improve the anti-interference ability of the TOF camera in the case of multiple TOF cameras in the range measurement.

In the first aspect, an embodiment of the present application provides an anti-interference ranging device, which may include:

A pulse position modulator, a phase shift keying modulator connected to the pulse position modulator (in the embodiment of this application, a binary phase shift keying BPSK modulator is taken as an example for illustration. The types of phase shift keying modulators include but Not limited to binary phase shift keying modulator);

The pulse position modulator is used to generate a baseband signal according to a random number signal; wherein the random number signal includes one or more random numbers, and each of the one or more random numbers corresponds to one random number. The pulse position of the baseband signal; when the random number signal has multiple consecutive identical random numbers, there are M pulse positions corresponding to the multiple consecutive identical random numbers in the baseband signal Time interval, M is an integer greater than 0; the phase of the random number signal and the baseband signal are synchronized;

The phase shift keying modulator is used to modulate a carrier signal and the baseband signal to generate a first signal; wherein, the first signal is used to drive a light emitter to generate a first pulsed light, and the first Pulsed light is used to illuminate the object to be measured.

The embodiment of the present application mainly adds a pulse position modulator (i.e. PPM modulator) to the anti-interference ranging device (such as a ranging chip) to reduce the continuous same random number, which causes the phase of the signal to be continuous and consistent, which affects the anti-interference ability of the signal. . Specifically, the PPM modulator receives a random number signal containing one or more random numbers, where each random number in the one or more random numbers corresponds to a pulse position of a baseband signal. According to the relevant parameters of the pulse position corresponding to the random number, the PPM modulator makes the required pulse position appear in the corresponding position in the modulated output baseband signal, and makes a certain number of time intervals between the two pulse positions; in different cameras The mapping relationship between the random number provided by the PPM modulator and the pulse position can be set to be different, so that the number of intervals between the two pulse positions in the baseband signal generated in each camera is different, thereby improving the resistance of the final output pulse light wave. The interference performance enables the camera to effectively recognize the pulsed light waves emitted by itself and filter the pulsed light waves emitted by other cameras. The embodiment of the present application does not limit the manner of determining the correspondence between the random number and the pulse position. Different from the prior art, the random number is directly sent to the phase shift keying modulator; when continuous 0 or continuous 1 occurs, the first signal output by the phase shift keying modulator is between each group of signal waves The phases may be the same continuously. Through the modulation order, in the case of multiple consecutive identical random numbers that may appear in the random number signal, the phases of consecutive groups of baseband signals in the output baseband signal will not be continuously the same, thereby improving the anti-interference ability of the signal. The operation of randomizing the waveform in the embodiment of this application uses randomized waveforms to transmit and pixel cross-correlation reception. Because random numbers have good auto-correlation and cross-correlation characteristics, the pixel cross-correlation reception will only transmit locally The signal is amplified and output, and other signals will be randomized, so that there will be no large errors in the ranging results.

In a possible implementation manner, the device further includes a phase-locked loop circuit connected to the phase-shift keying modulator; the phase-locked loop circuit is configured to generate the carrier signal according to a preset period, so The carrier signal is synchronized with the phase of the random number signal. In the embodiment of the present application, the phase-locked loop circuit is connected to the phase-shift keying modulator, and the carrier signal is generated through the phase-locked loop circuit, which is used to input phase-shift keying modulation for signal modulation, so as to output the first that meets the requirements. Signal.

In a possible implementation manner, the device further includes: a delay line circuit connected to the phase shift keying modulator; the delay line circuit is configured to determine the first phase delay value according to a preset phase delay value. One signal undergoes multiple phase delay operations to generate multiple pixel internal integration switch signals; each of the multiple phase delay operations corresponds to one pixel internal integration switch signal. In the embodiment of the present application, the first signal output by the phase shift keying modulation is delayed several times by the delay line circuit DLL, which is used to integrate the reflected light received subsequently, so as to calculate the difference between the object under test and the camera. The distance between.

In a possible implementation, the device further includes: a pixel array connected to the delay line circuit, and an optical lens connected to the pixel array; the optical lens is used to receive the second pulsed light, so The second pulsed light is the pulsed light reflected by the object to be measured; each pixel in the pixel array is used to determine the each pixel according to the internal integration switch signal of the plurality of pixels and the second pulsed light Multiple exposure signals corresponding to pixels. In the embodiment of the present application, a plurality of delayed switching signals and received second pulse light (that is, the reflected first signal) are exposed through a pixel array connected to a delay line circuit to obtain a plurality of exposure signals. And through the optical lens to receive the reflected second pulse light, used to further calculate the distance between the camera and the object.

In a possible implementation manner, the device further includes an analog-to-digital converter ADC connected to the pixel array; the ADC is used to convert multiple exposure signals corresponding to each pixel into multiple corresponding Digital signal. In the embodiment of the present application, the exposure signal (ie, the analog signal) is converted into multiple digital signals through the analog-to-digital converter connected to the pixel array, so that the relevant processing module can perform arithmetic processing on the digital signal to obtain the distance value.

In a possible implementation manner, the random number signal includes a plurality of random numbers lasting for a preset duration; the device further includes a random number generator connected to the pulse position modulator; the random number generator , Configured to generate the multiple random numbers lasting for a preset duration according to the random number generation period, where the preset duration is the same as the value of the random number generation period. In the embodiment of the present application, a random number generator is used to generate multiple random numbers, which are used to change the phase of each group of signal waves in the first signal, so that the anti-interference ability of the first signal is enhanced.

In a possible implementation manner, the random number signal includes a plurality of pseudo-random numbers lasting for a preset period of time; the device further includes a pseudo-random number generator connected to the pulse position modulator; the pseudo-random The number generator is used to generate a plurality of pseudorandom numbers for a preset duration according to the pseudorandom number generation period, the pseudorandom number period, and a preset initial pseudorandom number; the preset duration and the pseudorandom number generation The value of the period is the same. In the embodiment of the present application, multiple pseudo-random numbers are generated through a pseudo-random number generator and preset related generation parameters (such as pseudo-random number cycle period, etc.), which are used to change the phase of each group of signal waves in the first signal. The anti-interference ability of the first signal is enhanced.

In a possible implementation manner, the phases of the carrier signal and the baseband signal are synchronized. In the embodiment of the present application, by controlling the phase synchronization of the carrier signal and the baseband signal, it is convenient for the two to be integrated in the BPSK modulator to generate the first signal that meets the requirements.

In a possible implementation manner, the pulse position modulator is specifically configured to: according to the pulse position of each random number in the random number signal corresponding to the pulse position in the first mapping relationship table, transform the random number signal Modulated into the baseband signal, wherein the first mapping relationship table belongs to one of a plurality of mapping relationship tables corresponding to a first modulation order; the first modulation order is among a plurality of preset modulation orders Each of the multiple mapping relationship tables includes the mapping relationship between each of the random numbers and the pulse position of the baseband signal; the multiple mapping relationship tables and the multiple The preset modulation order corresponds to one by one. In the embodiment of the present application, the mapping relationship between the random number and the pulse position of the baseband signal is determined by the first modulation order (such as 2nd order, 4th order); in the case of continuous identical random numbers, it is beneficial to the same in the baseband signal. A time interval is generated before the pulse position and does not repeat continuously. For example, the PPM modulator will receive the random number signal and determine the pulse position of the baseband signal corresponding to the random number in the first mapping relationship table (corresponding to the first modulation order), and then output the modulated baseband signal. Wherein, the first mapping relationship table may be determined in multiple mapping relationship tables by the first modulation order; wherein, the mapping relationship table and the modulation order may both be pre-stored data; or further based on the known first modulation order. Determine the required first mapping table. Different modulation orders correspond to different mapping tables, and each mapping table contains the form of random numbers and the pulse position corresponding to each random number.

In the second aspect, an embodiment of the present application provides an anti-interference ranging method, including:

Generating a baseband signal according to a random number signal; wherein the random number signal includes one or more random numbers, and each random number in the one or more random numbers corresponds to a pulse position of the baseband signal; When there are multiple consecutive identical random numbers in the random number signal, there are M time intervals between pulse positions corresponding to the multiple consecutive identical random numbers in the baseband signal, and M is an integer greater than 0 ; The random number signal and the phase of the baseband signal are synchronized;

The carrier signal and the baseband signal are modulated to generate a first signal; wherein, the first signal is used to drive the light emitter to generate first pulsed light, and the first pulsed light is used to illuminate the object to be measured. Optionally, the first signal may include multiple sets of pulse waves (such as multiple sets of square waves).

In a possible implementation manner, the method further includes: controlling a light emitter to emit the first pulsed light according to the first signal.

In a possible implementation manner, the method further includes: generating the carrier signal according to a preset period, and the carrier signal is synchronized with the phase of the random number signal.

In a possible implementation, the method further includes: performing multiple phase delay operations on the first signal according to a preset phase delay value to generate multiple pixel internal integration switch signals; the multiple phase delay operations Each operation in the delay operation corresponds to a pixel internal integration switch signal.

In a possible implementation, the method further includes: receiving second pulsed light, where the second pulsed light is pulsed light reflected by the object to be measured; The second pulsed light determines a plurality of exposure signals corresponding to each pixel.

In a possible implementation manner, the method further includes: converting multiple exposure signals corresponding to each pixel into multiple corresponding digital signals.

In a possible implementation, the method further includes: receiving the corresponding multiple digital signals; obtaining the phase delay of the second pulsed light according to a ranging algorithm, and obtaining the phase delay of the second pulsed light according to the frequency of the second pulsed light Calculate the distance between the object to be measured and the anti-interference distance measuring device.

In a possible implementation, the method further includes: generating a plurality of pseudo-random numbers for a preset duration according to a pseudo-random number generation period, a pseudo-random number period, and a preset initial pseudo-random number; It is assumed that the duration is the same as the value of the pseudo-random number generation period.

In a possible implementation manner, the phases of the carrier signal and the baseband signal are synchronized.

In a possible implementation manner, the generating the baseband signal according to the random number signal includes: according to the pulse position of each random number in the random number signal corresponding to the pulse position in the first mapping relationship table, converting the random number signal The signal is modulated into the baseband signal, wherein the first mapping relationship table belongs to one of a plurality of mapping relationship tables corresponding to a first modulation order; the first modulation order is a plurality of preset modulation orders Each of the multiple mapping relationship tables includes a mapping relationship between each of the random numbers and the pulse position of the baseband signal; the multiple mapping relationship tables and the multiple There is a one-to-one correspondence with each preset modulation order.

In a third aspect, an embodiment of the present application provides an anti-interference ranging system, which is characterized in that it includes:

Pulse position modulator, a phase shift keying modulator connected to the pulse position modulator, a phase locked loop circuit connected to the phase shift keying modulator, and a delay line connected to the phase shift keying modulator A circuit, a pixel array connected to the delay line circuit, an analog-to-digital converter ADC connected to the pixel array, and a pseudo-random number generator connected to the pulse position modulator;

The phase shift keying modulator is used to modulate a carrier signal and the baseband signal to generate a first signal; wherein, the first signal is used to drive a light emitter to generate a first pulsed light, and the first Pulsed light is used to illuminate the object to be tested;

The phase-locked loop circuit is configured to generate a carrier signal according to a preset period, and the carrier signal is synchronized with the phase of the random number signal;

The pseudo-random number generator is configured to generate a plurality of random numbers that last for a preset duration according to a pseudo-random number generation cycle, a pseudo-random number cycle, and a preset initial pseudo-random number; the preset duration and the random number The value of the number generation period is the same;

The delay line circuit is configured to perform multiple phase delay operations on the first signal according to a preset phase delay value to generate multiple pixel internal integration switch signals; each of the multiple phase delay operations corresponds to Integral switch signal inside a pixel;

Each pixel in the pixel array is configured to determine a plurality of exposure signals corresponding to each pixel according to the internal integration switch signal of the plurality of pixels and the second pulse light;

The ADC is used to convert multiple exposure signals corresponding to each pixel into multiple corresponding digital signals.

In a possible implementation manner, the system further includes a light source driver and an illuminator connected to the phase shift keying modulator, the illuminator is connected to the light source driver; the light source driver is configured to The first signal controls the light emitter to emit the first pulsed light. In the embodiment of the application, the light source driver and the light emitter are connected with the phase shift keying modulator, and the light emitter is driven by the first signal to make the light emitter emit pulsed light with corresponding bright and dark information, which is used to illuminate the target object and measure the difference between the camera and the target object. The distance between.

In a possible implementation manner, the system further includes a ranging circuit connected to the ADC; the ranging circuit is configured to: receive the corresponding multiple digital signals; obtain the ranging algorithm according to the ranging algorithm; The phase of the second pulsed light is delayed, and the distance between the object to be measured and the anti-interference distance measuring device is calculated according to the frequency of the second pulsed light. In the embodiment of the present application, the distance between the camera and the object to be measured is obtained by calculating the received digital signal through the ranging circuit connected to the ADC.

In a possible implementation manner, the light emitter is a light emitting diode LED or a vertical cavity surface emitting laser VCSEL. In the embodiment of the present application, under the control of the first signal, an optical device such as an LED or a VCSEL emits pulsed light with different brightness and darkness, so as to measure the distance of the object.

In a possible implementation, the system further includes: an optical lens connected to the pixel array; the optical lens is used to receive the second pulsed light, and the second pulsed light is the to-be-measured Pulse light reflected by objects.

In a fourth aspect, an embodiment of the present application provides an electronic device, which may include: the anti-interference ranging device as described in the first or second aspect above, and a discrete device coupled to the outside of the anti-interference ranging device .

In a fifth aspect, an embodiment of the present application provides a terminal, the terminal includes a processor, and the processor is configured to support the terminal to perform a corresponding function in the anti-interference ranging method provided in the third aspect. The terminal may also include a memory, which is used for coupling with the processor and stores necessary program instructions and data for the terminal. The terminal may also include a communication interface for the terminal to communicate with other devices or communication networks.

In a sixth aspect, an embodiment of the present application provides a radar. The radar may include the device described in the first aspect or the system described in the third aspect, for implementing the anti-interference detection provided by the device or the system. Distance function. The radar may also include a memory coupled to the device or the system for storing program instructions and data necessary for the radar; the radar may also include an external power supply coupled to the device or the system, and the The external power supply is used to supply power to the radar.

In a seventh aspect, an embodiment of the present application provides a vehicle equipped with the device described in the first aspect or the system described in the third aspect, and is used to implement the anti-interference ranging provided by the device or the system Function. The vehicle may also include an automatic driving system for controlling the driving of the vehicle according to road conditions. The vehicle may also include an external discrete device coupled to the device or the system.

In an eighth aspect, the embodiments of the present application provide a method for continuous wave exposure modulation four times; it may include phase 0° exposure, phase 180° exposure, phase 90° exposure, and phase 270° exposure respectively in the continuous wave. Specifically, continuous wave phase 0° and phase 180° exposure, phase 90° and phase 270° exposure, phase 180° and phase 0° exposure, and phase 270° and phase 90° exposure are sequentially performed.

In a ninth aspect, an embodiment of the present application provides a method for continuous wave exposure and modulation twice; it may include phase 0° exposure, phase 180° exposure, exposure, and phase 270° exposure respectively in the continuous wave. Specifically, the continuous wave is sequentially exposed with a phase of 0° and a phase of 180°, and the phase is exposed with a phase of 90° and a phase of 270°.

In a tenth aspect, an embodiment of the present application provides a method for pulse wave exposure and modulation twice; it can be included in the pulse wave, and the phase 180° and the phase 0° are respectively exposed and modulated. Specifically, the continuous wave is sequentially exposed at a phase of 0° and a phase of 180°, and exposed at a phase of 180° and a phase of 0°.

In the eleventh aspect, an embodiment of the present application provides a pulse wave exposure and modulation method once; it may be included in the pulse wave, and the phase 0° and the phase 180° are respectively exposed. Specifically, the phase 0° and the phase 180° are exposed in the order of exposure. Optionally, the phase 180° and the phase 0° are exposed according to another exposure sequence.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings that need to be used in the description of the embodiments.

FIG. 1 is a schematic diagram of a TOF application scenario provided by an embodiment of the present application;

Figure 2 is a schematic diagram of another TOF application scenario provided by an embodiment of the present application;

FIG. 3 is a schematic diagram of another TOF application scenario provided by an embodiment of the present application;

FIG. 4 is a schematic diagram of a multi-camera ranging scene based on FIG. 3 provided by an embodiment of the present application;

FIG. 5 is a schematic diagram of the architecture of a multi-camera ranging system provided by an embodiment of the present application;

FIG. 6 is a schematic structural diagram of an anti-interference ranging device provided by an embodiment of the present application;

FIG. 7 is a schematic structural diagram of an anti-interference ranging device provided by an embodiment of the present application;

FIG. 8 is a schematic flowchart of a transmitting end provided by an embodiment of the present application;

FIG. 9 is a schematic diagram of a binary random number signal provided by an embodiment of the present application;

FIG. 10 is a schematic diagram of a random number signal and a carrier signal provided by an embodiment of the present application;

FIG. 11 is a schematic diagram of a PPM modulation provided by an embodiment of the present application;

FIG. 12 is a schematic diagram of a waveform of a BPSK modulator provided by an embodiment of the present application;

FIG. 13 is a schematic structural diagram of another anti-interference ranging device provided by an embodiment of the present application;

FIG. 14 is a schematic flowchart of a receiving end provided by an embodiment of the present application;

15 is a schematic diagram of signals of a first pulsed light and a second pulsed light provided by an embodiment of the present application;

FIG. 16 is a schematic diagram of a signal using a square wave signal as an example according to an embodiment of the present application;

FIG. 17 is a schematic diagram of a DLL structure provided by an embodiment of the present application;

FIG. 18 is a schematic diagram of another TOF ranging principle provided by an embodiment of the present application;

FIG. 19 is a schematic diagram of four continuous wave exposure modulation provided by an embodiment of the present application;

20 is a schematic diagram of two continuous wave exposure modulation provided by an embodiment of the present application;

FIG. 21 is a schematic diagram of a pulse wave exposure modulation provided by an embodiment of the present application;

FIG. 22 is a schematic diagram of a pulse wave exposure modulation provided by an embodiment of the present application;

FIG. 23 is a schematic diagram of an anti-interference ranging method provided by an embodiment of the present application;

FIG. 24 is a schematic diagram of an anti-interference ranging method provided by an embodiment of the present application;

FIG. 25 is a schematic structural diagram of a device provided by an embodiment of the present application.

Detailed ways

The embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

The terms "first", "second", "third" and "fourth" in the specification and claims of this application and the drawings are used to distinguish different objects, not to describe a specific order ; And the objects described by the terms "first", "second", "third" and "fourth" may also be the same objects, or contain each other or have other relationships. In addition, the terms "including" and "having" and any variations of them are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes unlisted steps or units, or optionally also includes Other steps or units inherent to these processes, methods, products or equipment.

The reference to "embodiments" herein means that a specific feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art clearly and implicitly understand that the embodiments described herein can be combined with other embodiments.

The terms "component", "module", "system", etc. used in this specification are used to denote computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, the component may be, but is not limited to, a process, a processor, an object, an executable file, an execution thread, a program, and/or a computer running on a processor. Through the illustration, both the application running on the computing device and the computing device can be components. One or more components may reside in processes and/or threads of execution, and components may be located on one computer and/or distributed among two or more computers. In addition, these components can be executed from various computer readable media having various data structures stored thereon. The component can be based on, for example, a signal having one or more data packets (e.g. data from two components interacting with another component in a local system, a distributed system, and/or a network, such as the Internet that interacts with other systems through a signal) Communicate through local and/or remote processes.

First of all, some terms in this application are explained to facilitate the understanding of those skilled in the art.

(1) Binary Phase Shift Keying (BPSK) is one of the conversion methods for converting analog signals into data values. It uses a combination of complex waves that deviate from the phase to express the information keying phase shift method. BPSK uses a standard sine wave and a phase-reversed wave, making one side 0 and the other side 1, so that two-value (1 bit) information can be transmitted and accepted at the same time.

(2) Pulse position modulation (Pulse Position Modulation, PPM), by modulating the signal, only the generation time of each pulse in the carrier pulse series is changed, without changing its shape and amplitude, and the proportion of the change in the generation time of each pulse Regarding the amplitude of the modulating signal voltage, it has nothing to do with the frequency of the modulating signal.

(3) Vertical-Cavity Surface-Emitting Laser (VCSEL) is a type of semiconductor. The laser is emitted perpendicular to the top surface. It is the same as the independent chip manufacturing process that is generally used for cutting. The laser is emitted from the edge. The type of laser is different.

(4) The random number is the result of a special random experiment. The most important characteristic of random numbers is that the number behind it has nothing to do with the number in front.

(5) Pseudo-random numbers are calculated from a uniformly distributed random number sequence from [0,1] using a deterministic algorithm. It is not truly random, but has statistical characteristics similar to random numbers, such as uniformity and independence.

(6) The baseband signal is the original electrical signal sent by the information source without modulation (spectrum shifting and transformation). It is characterized by a low frequency. The signal spectrum starts near zero frequency and has a low-pass form.

(7) Carrier, or carrier signal, refers to the waveform that is modulated to transmit the signal. The frequency band of the baseband signal is very wide (infinitely wide in theory), but due to the bandpass, there is almost no transmission medium with infinite bandwidth, so the baseband signal cannot be transmitted over a long distance on the ordinary medium, otherwise the inter-symbol interference and attenuation cannot be used. The signal is recovered, so the baseband signal is modulated with the carrier to reduce the bandwidth, so that the signal can be transmitted reliably, and the attenuation can be reduced. The receiving end will demodulate and restore the original digital signal.

(8) Delay-locked loop (DLL) technology is widely used in the field of timing, and it is a delay line with a controllable delay. Among them, the delay line is an element or device used to delay an electrical signal for a period of time. The delay line should have flat amplitude-frequency characteristics and certain phase shift characteristics (or delay frequency characteristics) in the passband, with appropriate matching impedance and small attenuation.

(9) Analog-to-digital conversion (ADC), that is, A/D converter, usually refers to an electronic component that converts an analog signal into a digital signal. The usual analog-to-digital converter converts an input voltage signal into an output digital signal. Since the digital signal itself has no practical meaning, it only represents a relative magnitude. Therefore, any analog-to-digital converter needs a reference analog quantity as the conversion standard, and the most common reference standard is the largest convertible signal size. The output digital quantity represents the magnitude of the input signal relative to the reference signal.

(10) Pseudo-random number cycle refers to the number of pseudo-random numbers that do not repeat in a pseudo-random number sequence with periodic recurring cycles, or the number of numbers contained in a cycle in the iterative process of generating pseudo-random numbers. Use a certain recurrence formula to generate pseudo-random numbers according to a certain procedure. Generally, a pseudo-random number sequence x1, x2, ... is generated starting from a certain initial value; if there is m, for any n, xn+m=xn(n=1, 2...), then the minimum m that satisfies the above relationship is called the period of pseudo-random number.

(11) Binary On-Off Keying (OOK), also known as Binary Amplitude Keying, uses a unipolar non-return-to-zero code sequence to control the opening and closing of the sinusoidal carrier.

(12) Among multiple phase-shift keying (MPSK), the most commonly used is quadrature phase-shift keying, namely QPSK (Quadrature Phase Shift Keying), which is QPSK when transmitting digital TV signals in satellite channels. Modulation. It can be regarded as composed of two 2PSK modulators. The input serial binary information sequence is converted into two-way rate halved sequence after serial-parallel conversion. The level converter generates bipolar two-level signals I(t) and Q(t) respectively, and then the carrier Acos2πfct It is modulated with Asin2πfct, and the QPSK signal can be obtained after the addition.

(13) Three-dimensional (3-dimension, 3D) refers to the three axes of the coordinate axis, namely x-axis, y-axis, and z-axis, where x represents left and right space, y represents upper and lower space, and z represents front and rear space. However, in practical applications, the X axis is generally used to describe the left and right movement, the Z axis is used to describe the up and down movement, and the Y axis is used to describe the front and back movement, forming a person's visual three-dimensional sense.

(14) Phase is the position of a wave in its cycle at a specific moment, that is, a scale of whether it is at the peak, trough or some point between them. Phase describes the measurement of signal waveform change, usually in degrees (angle), also known as phase angle. When the signal waveform changes in a periodic manner, the waveform cycle is 360°.

(15) Time of flight (ToF) ranging method is a two-way ranging technology, which mainly uses the flight time between two asynchronous transceivers (Transceiver) (or reflected surface) to measure inter-node distance. Traditional ranging technology is divided into two-way ranging technology and one-way ranging technology. In a better signal level modulation or in a non-line-of-sight environment, the estimated result based on RSSI (Received Signal Strength Indication) ranging method is ideal; in a line-of-sight environment, it is estimated based on ToF distance The method can make up for the shortcomings of the distance estimation method based on RSSI. However, the ToF ranging method has two key constraints: one is that the sending device and the receiving device must always be synchronized; the other is the length of the signal transmission time provided by the receiving device. In order to achieve clock synchronization, the ToF ranging method uses a clock offset to solve the clock synchronization problem.

In order to facilitate the understanding of TOF camera imaging, some common application scenarios are listed below, which can include the following three scenarios.

Scenario 1: Applied to vehicles and related systems.

In automotive applications, TOF can be used for automatic driving, collision avoidance automatic braking, and so on. Supported by the time-of-flight (TOF) principle, the system mounted on the vehicle can accurately detect the driver's body and head position, and even capture the blinking motion of the driver when he wears glasses or sunglasses to determine whether the driver is paying attention Enough concentration and whether you are driving with fatigue, so as to initiate corresponding countermeasures. For example, by vibrating the seat or warning sound. The less the driver’s attention is, the more the car will pay attention. In order to respond quickly and accurately, the auxiliary system and the emergency braking system can be automatically activated before a potential emergency occurs. In addition, the technology can also control the in-vehicle entertainment system or car air conditioner through hand movement or body posture, and even implement new auxiliary and safety functions outside the car, such as door opening assist devices, to prevent the car door from opening when in a parking lot or a home basement. After hitting another car, wall or ceiling.

Specifically, please refer to FIG. 1, which is a schematic diagram of a TOF application scenario provided by an embodiment of the present application; as shown in FIG. 1, a vehicle equipped with a TOF system (or TOF camera) can measure the previous vehicle through this technology The distance D. When the distance D is less than the preset safety distance, reduce the vehicle speed or stop. Among them, the vehicle equipped with TOF can be an unmanned car.

Scenario 2: Applied in the field of human-computer interaction.

TOF provides a real-time remote image, so it can be used very simply to record human movements. This makes many consumer electronic products (such as TV) have a new way of interaction. By carrying the TOF sensor, the depth data of the target object can be obtained. Specifically, the infrared projector continuously sends out infrared pulses, and the phase delays of the infrared pulses reflected on objects at different distances are inconsistent. Then the infrared sensor is used to receive the feedback message, and the pulsed light with different phase delays will be received by the four-phase on the infrared sensor and output different phase values. In this way, the depth information of the object captured by each pixel is determined, and objects of different depths can be distinguished. The application of this technology can realize human-computer interaction, and the application in games is more extensive.

Specifically, please refer to FIG. 2, which is a schematic diagram of another TOF application scenario provided by an embodiment of the present application; as shown in FIG. 2, a display equipped with a TOF system can recognize movement changes of a human object. When the display is running a game that needs to control the character according to the human movement, the TOF camera is used to recognize the movement of the human object, so as to realize the corresponding control of the character in the game.

Scenario 3: Applied in machine vision.

In the application of industrial machine vision, robots use TOF cameras for object classification and precise positioning and placement. In addition, TOF has an irreplaceable position in robotics, face recognition, and geomorphological mapping. Specifically, please refer to FIG. 3, which is a schematic diagram of another TOF application scenario provided by an embodiment of the present application; in the 3D scenario shown in the figure, electromagnetic waves are emitted to the seat through the TOF system, and then the foregoing is received by the receiver. Electromagnetic wave feedback signal. In the TOF system, the time is calculated by a timer. Calculate the distance between the seat and the TOF camera based on the aforementioned information.

When multiple TOF cameras measure the distance of the target object, it is necessary to consider improving the anti-interference ability of the signal between the TOF cameras. Please refer to FIG. 4, which is a schematic diagram of a multi-camera ranging scene based on FIG. 3 provided by an embodiment of the present application; as shown in FIG. The distance signal 1 is used to measure the distance between the camera 1 and the target object according to the reflected signal 1'. At the same time, the camera 2 sends a signal 2 to the target object, and the distance between the camera 2 and the target object is measured according to the received signal 2'. However, due to the presence of two cameras for distance measurement at the same time, the camera 1 may receive the feedback signal 2'of the signal 2 sent by the camera 2, resulting in deviation of the distance measurement. For example, when there are multiple TOF cameras (ie TOF modules) in the scene, the active light emitted by TOF module 1 is likely to be received by another TOF module (such as module 2). If module 2 is exposed If the pulsed light wave emitted by the module 1 is received, the result will be wrong when the distance measurement calculation is performed.

It is understandable that the application scenarios shown in FIGS. 1 to 4 are only an exemplary scenario in the embodiment of the present application, and the application scenarios in the embodiment of the present application include but are not limited to the above application scenarios.

The above introduces several application scenarios of TOF ranging. The following describes a system architecture based on the embodiment of this application in conjunction with the application scenario of FIG. 4. Please refer to FIG. 5. FIG. A schematic diagram of the camera ranging system architecture; as shown in FIG. 5, the system architecture includes a ranging module 1 (that is, a TOF module, applied to a depth camera, that is, a TOF camera) and a ranging module 2. The embodiments of the present application are applied to a ranging system with multiple TOF cameras. In order to solve the problem of mutual interference when multiple cameras work, the embodiment of the present application allows the pixel reference waveforms emitted by each camera to be orthogonal to each other when performing distance measurement, so that the camera will not be affected by interference signals when performing TOF exposure (related reception) Influence.

Wherein, the ranging module 1 and the ranging module 2 have the same structural composition, and the embodiment of the present application takes one of the ranging module (such as the ranging module 1) as an example for description. The ranging module includes a light emitter, a light source driver, a ranging chip and a lens. Specifically, the ranging module 1 includes a light emitter 1, a light source driver 1, a ranging chip 1, and a lens 1. Optionally, the architecture of the multi-camera ranging system may also include multiple other ranging modules. In FIG. 5, two ranging modules are used as an example for illustration.

Specifically, the ranging chip may also include a controller, a pixel array, and an analog-to-digital converter; where, taking the ranging chip 1 as an example, the controller 1 sends a driving signal to the laser driver (or light source driver) 1, and the laser driver 1 controls The laser 1 transmits pulsed light containing bright and dark information (that is, corresponding to the driving signal). After the pulsed light irradiates the target object and is reflected, the reflected pulsed light is received by the lens 1. At this time, the pixel array 1 calculates the signal result according to the delayed drive signal generated by the controller 1 and the received reflected pulse light, and outputs an analog signal. The analog signal is converted into a digital signal by the analog-to-digital converter 1 to perform the next calculation of the distance result.

It is understandable that the system architecture in FIG. 5 is only an exemplary implementation in the embodiment of the present application, and the system architecture in the embodiment of the present application includes but is not limited to the above system architecture.

The following describes a specific architecture in the ranging module involved in the embodiment of the present application. Please refer to FIG. 6, which is a schematic diagram of the architecture of an anti-interference ranging device provided by an embodiment of the present application; as shown in FIG. 6, the system architecture is illustrated by taking the ranging module 1 as an example, which includes ranging The module 10 (corresponding to the distance measurement module 1 in FIG. 5) and the distance measurement circuit (or called the distance measurement module) 20; specifically, the distance measurement module 10 may include a distance measurement chip 101 (corresponding to the distance measurement module in FIG. 5). Chip 1), light source driver 102 (corresponding to light source driver 1 in FIG. 5), light emitter 103 (corresponding to light emitter 1 in FIG. 5), and the lens (corresponding to distance measuring module 1 in FIG. 5). A general lens can include Filter) 104. in,

The ranging chip 1 (101) can include: random/pseudo-random number generator 1010, PPM modulator (ie pulse position modulator or pulse position modulator) 1011, BPSK modulator (ie binary phase shift keying modulator) ) 1012, a phase-locked loop circuit 1013, a delay line circuit DLL1014, a pixel (pixel) array 1015, and an analog-to-digital converter 1016. Specifically, firstly, the principle of TOF ranging is described. The phase-locked loop circuit 1013 inside the TOF system generates a square wave with a certain frequency (for example, 20MHz), and this waveform drives the light emitter 1 (103, such as VCSEL/LED) light up. The reflected light is focused on the pixel array 1 (1015) through the lens 1 (104). The pixel array 1 (1015) can use the same frequency (for example, 20MHz) but there is a phase delay (0 degree, 90 degree, 180 degree, 270 degree). The switch circuit of the degree) integrates the received optical signal and outputs the corresponding value. The phase delay caused by the flight time can be calculated through the phase calculation. Among them, the random/pseudo-random number generator 1010 is used to generate a random number of the control signal phase; taking the random number generator as an example, the random number generator is used to generate a random number of 0 or 1 random number.

The pulse position modulator 1011 (hereinafter referred to as the PPM modulator) is used to generate a baseband signal with strong anti-interference ability according to the random number signal. When the same continuous random number (such as continuous "0" or continuous "01") appears in the random number signal, in the baseband signal, the phase in the signal band synchronized with the continuous same random number will not appear Continuous repetition (for example, the phases corresponding to 0, 0, and 0 are all 0 degrees, but due to the effect of the PPM modulator 1011, there will be a certain time interval between the 0 degree phase and the next 0 degree phase). When there are no multiple consecutive identical random numbers in the random number signal, the pulse position corresponding to the random number can also be determined according to the pulse position mapping table of the random number. For example, a certain segment of the random number in the random number signal is "01011001", or It can be modulated by the PPM modulator 1011. It is understandable that "0", "00" and "001" can all be regarded as a kind of random number, which is not limited in the embodiment of the present application. ; And in the case of long continuous 0 or long continuous 1 in the random number signal, by adding the PPM modulator 1011, the phase difference between the pulsed light sent by each ranging camera becomes larger, even if the camera is illuminated by other cameras The pulsed light on the object can also be effectively filtered and shielded by the algorithm.

In a possible implementation manner, the random number signal is modulated into a baseband signal according to the corresponding pulse position of each random number in the random number signal in the first mapping relationship table, where the first mapping relationship table belongs to multiple One of the mapping relationship tables corresponding to the first modulation order; the first modulation order is one of a plurality of preset modulation orders; each mapping relationship table in the plurality of mapping relationship tables includes each of the random The mapping relationship between the number and the pulse position of the baseband signal; the multiple mapping relationship tables correspond to the multiple preset modulation orders one-to-one. For example, the PPM modulator receives a random number signal and analyzes each random number in the random number signal. According to the first mapping table in the PPM modulator, determine the pulse position of the baseband signal corresponding to each random number in the random number signal; modulate the random number signal into a baseband signal. Wherein, the first mapping relationship table is related to the modulation order of the PPM modulator. For example, the 8th order modulation order corresponds to the 8th order mapping table, and the 16th order modulation order corresponds to the 16th order mapping table. Optionally, the PPM modulator can store only one kind of modulation order and the mapping relationship table corresponding to this kind of modulation order; or store multiple modulation orders and one for each modulation order of the multiple modulation orders Mapping table. Further optionally, the PPM modulator only stores several modulation orders; when the user selects a certain modulation order, a corresponding mapping relationship table is generated. The embodiment of the application does not limit this.

The phase shift keying modulator 1012 (ie, binary phase shift keying modulator) is used to modulate the carrier signal and the baseband signal to generate the first signal. Optionally, the phase shift keying modulator 1012 may include a binary phase shift keying modulator (the embodiment of this application is described as an example), a quaternary phase shift keying modulator, and an octal phase shift keying modulator. , Hexadecimal phase shift keying modulator or decimal binary phase shift keying modulator.

It can be understood that PSK modulation is to add the information of the modulation signal to the phase of the carrier. For example, the 0 phase of the carrier represents the "1" level of the modulation signal, and the 180° phase represents the "0" level of the modulation signal. If the phase of the carrier is further subdivided into m different phases, generally m=2N, and N is a positive integer. The common ones are m=4, 8, 16, 32, which are called 4PSK, 8PSK, etc. respectively. In this way, each carrier with a specific phase represents N bits of information.

The phase-locked loop circuit 1013 is used to generate a carrier signal with a fixed period. For example, the pulse period of the square wave generated by the phase-locked loop circuit 1013 is Tp.

The delay line circuit DLL1014 is used to perform multiple phase delay operations on the aforementioned first signal according to a preset phase delay value to generate multiple pixel internal integration switch signals; each of the aforementioned multiple phase delay operations corresponds to a pixel internal Integral switch signal.

The pixel array 1 (1015) is used for integrating the delayed first signal and the first signal reflected by the target object, and outputting various simulation parameters for calculating the distance.

The analog-to-digital converter 1 (1016) is used to convert various analog parameters into digital parameters.

The ranging circuit 20 is used to obtain the distance between the ranging camera and the target object according to the digital parameters and the preset ranging algorithm or formula. Optionally, when the distance measurement circuit is adopted in the hardware structure, the calculation of the input signal is completed through a certain circuit structure and the distance result is output. Optionally, when the corresponding distance measurement function is completed through a software program, that is, the input signal is used as an operation parameter through a preset computer program or code, and then the corresponding distance result is output.

It can be understood that the system architecture in FIG. 6 is only an exemplary implementation in the embodiments of the present application, and the application scenarios in the embodiments of the present application include but are not limited to the above application scenarios.

In the following, in conjunction with the system architecture shown in FIG. 6 above, the technical problems proposed in this application will be specifically analyzed and resolved.

Please refer to FIG. 7, which is a schematic structural diagram of an anti-interference ranging device provided by an embodiment of the present application; the anti-interference ranging device can be applied to the transmitting end of the anti-interference ranging device. Among them, the anti-interference ranging device includes a random/pseudo-random number generator 1010, a pulse position modulator 1011 (ie a PPM modulator), a binary phase shift keying modulator 1012 (ie a BPSK modulator), and a phase locked loop circuit 1013 , Laser driver 102 and light emitter 103. The connection mode of each circuit or module can be as shown in Figure 7. Optionally, the device may include a random/pseudo-random number generator 1010, a phase-locked loop circuit 1013, a laser driver 102, and a light emitter 103.

Please refer to FIG. 8. FIG. 8 is a schematic flowchart of a transmitting end provided by an embodiment of the present application; as shown in FIG. 8, based on the structural relationship shown in FIG. 7, the following steps may be included:

Step 1: Set the random number generation period (Tr), pseudo-random number period (N), phase-locked loop pulse generation period (Tp), and PPM modulation order (M).

Step 2: The random number generator 1010 generates a random number R according to Tr, or the pseudo-random number generator 1010 generates a pseudo random number R according to Tr, a pseudo-random number period N and a preset initial state. At the same time, the parallel phase-locked loop circuit 1013 generates a square wave L with a pulse period of Tp according to Tp (for the BPSK modulator 1012, L is the carrier wave), and the L and R phases are synchronized.

Step 3: The PPM modulator 1011 outputs the modulated PPM signal P (for the BPSK modulator 1012, P is the baseband signal) according to the set modulation order M and the input signal R, and the P and L phases are synchronized.

Step 4: The BPSK modulator 1012 performs BPSK modulation on the carrier L and the baseband signal P, and outputs a modulated signal P1 (the P1 signal is a pulse sequence of digital 0 or 1).

Step 5: The P1 signal passes through the light source driver 102 to make the light emitter 103 (such as VCSEL or LED) emit pulsed light with corresponding bright and dark information.

Among them, the aforementioned random/pseudo-random number generator 1010 is specifically used to generate a binary random number; the aforementioned binary random number controls the phase change of the baseband signal, and finally controls the phase of the waveform sent by the light emitter. For example, binary 0 corresponds to phase 0 degrees, and binary 1 corresponds to phase 180 degrees. It is understandable that a continuous binary random number can be regarded as a random number signal. Please refer to FIG. 9. FIG. 9 is a schematic diagram of a binary random number signal provided by an embodiment of the present application; as shown in FIG. 9, high level 1 Represents the binary number 1, and the low level 0 represents the binary number 0. Figure 9 lists three kinds of random number signals, including random number signal 1, random number signal 2 and random number signal 3; among them, each kind of random number signal is just a certain segment of the random number signal, which is used for example description Random numbers do not represent a certain rule; the appearance of 0 and 1 is random. The embodiment of the present application does not limit the random number in the random number signal.

In a possible implementation manner, the aforementioned device further includes a phase-locked loop circuit connected to the aforementioned BPSK modulator; the aforementioned phase-locked loop circuit is used to generate a carrier signal according to a preset period, and the aforementioned carrier signal is combined with the aforementioned random number signal. The phase is the same. In a possible implementation manner, the phases of the aforementioned carrier signal and the aforementioned baseband signal are synchronized. For example, the parallel phase-locked loop circuit 1013 is used to generate a square wave L with a pulse period of Tp according to Tp (for a BPSK modulator, L is the carrier), and L and R are phase synchronized (that is, a set of waveforms in L) The duration is the same as the duration of a random number in the random number signal, and the generation time and end time are the same). For example, please refer to FIG. 10, which is a schematic diagram of a random number signal and a carrier signal provided by an embodiment of the present application; as shown in FIG. 10, each random number corresponds to a set of waveforms in the square wave L (generally a set of waveforms). The waveform includes the entire high and low levels). The square wave L is an unmodulated signal. The random number signal in FIG. 10 is explained by taking a certain segment of random numbers in the random number signal 1 in FIG. 9 as an example.

The pulse position modulator 1011 is used to generate a baseband signal according to a random number signal. The two consecutive sets of signals in the aforementioned baseband signal have different phases; optionally, the baseband signal is generated by combining the random number signal with the first mapping relationship table; wherein, The aforementioned random number signal includes one or more random numbers, and each random number corresponds to a phase of the aforementioned baseband signal. Through the PPM modulator, the same random number in the aforementioned random number signal corresponds to the discontinuous phase of the aforementioned baseband signal. Repeated multiple times; the phase of the aforementioned random number signal and the aforementioned baseband signal are synchronized. Specifically, the random number signal is modulated into the baseband signal according to the corresponding pulse position of each random number in the random number signal in the first mapping relationship table, wherein the first mapping relationship table includes each The mapping relationship between the random number and the pulse position of the baseband signal; the first mapping relationship table corresponds to the preset modulation order; the corresponding random number in the first mapping relationship table according to the random number signal The pulse position modulates the random number signal into the baseband signal. For example, the first mapping relationship table is a fourth-order mapping relationship table; then, according to the modulation order 4, the fourth-order mapping relationship table among the multiple mapping relationship tables is determined to be the first mapping relationship table. Optionally, the modulation order may include multiple orders, for example, 2nd, 4th, 8th and so on.

Optionally, the random number signal is modulated into the baseband signal according to the corresponding pulse position of each random number in the random number signal in the first mapping relationship table, wherein the first mapping relationship table Belongs to one of the multiple mapping relationship tables corresponding to the first modulation order; the first modulation order is one of a plurality of preset modulation orders; each mapping relationship table in the multiple mapping relationship tables It includes a mapping relationship between each of the random numbers and the pulse position of the baseband signal; the multiple mapping relationship tables correspond to the multiple preset modulation orders one-to-one. For example, according to the known modulation order and mapping relationship table, the baseband signal is generated by combining the random number signal. The device can pre-store multiple mapping relation tables and modulation orders corresponding to the multiple mapping relation tables one-to-one. After the modulation order is determined, the corresponding mapping relationship table can be obtained, which is used to further modulate the random number signal. Optionally, the PPM modulator stores multiple modulation orders and mapping relationship tables corresponding to the multiple modulation orders.

For example, please refer to Table 1. Table 1 is a mapping table of 2PPM modulation order provided in the embodiment of the present application; as shown in Table 1, for example, a random number 0 corresponds to 10 under a 2PPM mapping relationship; a random number 1 Corresponds to 01 under the 2PPM mapping relationship. When the random number generator generates multiple continuous random numbers 0, according to the mapping relationship provided in Table 1, the multiple continuous random numbers 0 are mapped into multiple continuous 10s. Then, for example, the modulated random number signal corresponding to continuous "000" is "101010", which can make 1 and 0 not appear continuously, so as to influence the phase of the final signal to be discontinuous. Please refer to FIG. 11, which is a schematic diagram of PPM modulation provided by an embodiment of the present application; as shown in FIG. 11, the random number signal 4 is "110001"; after PPM modulation, the baseband signal (that is, the pulse in the figure) The position modulation signal, that is, the PPM signal, corresponds to the aforementioned signal P) is "010110101001", where "11" corresponds to "0101", making 1 discontinuous and repeating multiple times; "000" corresponds to "101010" making multiple zeros discontinuous Repetitions. To a certain extent, it reduces the occurrence of consecutive 1s or consecutive 0s. More specifically, a certain random number is "00"; according to the mapping rule of Table 1, the number sequence is "1010".

Table 1

OOK OOK		2PPM2PPM
00	1010
11	0101

Table 2 is a mapping table of 4PPM modulation order provided by an embodiment of the present application. The specific mapping relationship is shown in Table 2. Please refer to the corresponding description of Table 1, which will not be repeated here. The embodiment of the present application does not limit the order of the modulation order, and the modulation order may also include 8PPM.

Table 2

OOK

4PPM

0000	10001000
0101	01000100
1010	00100010
1111	00010001

It is understandable that the foregoing Table 1 and Table 2 are both a mapping relationship table corresponding to the modulation order; the embodiment of the present application does not limit how to determine the mapping relationship table. Optionally, a modulation order (such as 2nd order) and a corresponding mapping relationship table are preset in the PPM modulator; then, in the process of baseband signal modulation by the PPM modulator, according to the random number and the known two Order mapping table, generate baseband signal from the input random number signal. Optionally, a modulation order (such as fourth-order) is preset in the PPM modulator, but no corresponding mapping table is preset; then, during the operation of the PPM modulator, first according to the fourth-order modulation order Determine the fourth-order mapping relationship table. Wherein, the fourth-order mapping relationship table may be one of a plurality of mapping relationship tables stored in the memory of the ranging device (namely, the first mapping relationship table); or the ranging device obtains the fourth-order mapping relationship through the network or related algorithms. The mapping relationship table corresponding to the modulation order. Then according to the random number signal and the fourth-order mapping relationship table, the random number signal is modulated into the required baseband signal.

Binary phase shift keying modulator (hereinafter referred to as BPSK modulator), used to modulate the carrier signal (ie square wave L) and the aforementioned baseband signal (ie signal P) to generate a first signal (P1) containing multiple sets of pulse waves ); Among them, the phases of the two consecutive sets of pulse waves in the foregoing multiple sets of pulse waves are different. Please refer to FIG. 12, which is a schematic diagram of the waveform of a BPSK modulator provided by an embodiment of the present application; as shown in FIG. 12, the square wave L, the pulse position modulation signal P, and the first signal P1 are all exemplary waveforms; Among them, the random number signal shown in the figure is a segment of the random number signal, such as "00"; according to the aforementioned mapping rule, the pulse position modulation signal corresponding to "00" is "1010"; the square wave L shown in the figure is the carrier signal, The pulse signal P1 is generated according to the carrier signal and the pulse position modulation signal. In Fig. 12, 0 means not changing the phase corresponding to the square wave L, and 1 means changing the phase corresponding to the square wave L pseudo 180°; therefore, the phase of the waveform relative to 1 in the pulse signal P1 becomes 180°. It is understandable that there are many square wave pulses corresponding to one pulse signal P period; in the embodiment of the present application, the multiple pulses in the figure are taken as an example for description.

Please refer to FIG. 13, which is a schematic structural diagram of another anti-interference ranging device provided by an embodiment of the present application; the anti-interference ranging device can be applied to the receiving end of the anti-interference ranging device. The anti-interference ranging device may include a pulse position modulator (ie PPM modulator) 1011, a binary phase shift keying BPSK modulator 1012 connected to the pulse position modulator 1011, a delay line circuit DLL 1014, a pixel array 1015, and a ranging circuit 20. Optionally, the device may further include a pseudo-time-digital generator connected to the PPM modulator 1011, a phase-locked loop circuit 1013 connected to the BPSK modulator, a lens 104, and an analog-to-digital converter 1016.

With reference to the structure of FIG. 12, the ranging process involved in the receiving end of the embodiment of the present application will be analyzed below. Please refer to FIG. 14, which is a schematic flowchart of a receiving end provided by an embodiment of the present application; as shown in FIG. 14, the following steps may be included:

Step 2: The random number generator 1010 generates a random number R according to Tr, or the pseudo-random number generator generates a pseudo random number R according to Tr, a pseudo-random number period N and a preset initial state. At the same time, a phase-locked loop circuit 1013 connected to the BPSK modulator 1012 is used to generate a carrier signal according to a preset period, and the phase of the carrier signal and the random number signal are the same. For example, the parallel phase-locked loop circuit 1013 generates a square wave L with a pulse period of Tp according to Tp (for the BPSK modulator 1012, L is the carrier wave), and the L and R phases are synchronized.

Step 5: The delay line circuit 1014 performs a time delay operation on the input P1, and outputs P2. (The DLL delay value of different TOF systems will be different. For example, the first exposure is not delayed, the second exposure is delayed by 1/4 cycle, the third exposure is delayed by 1/2 cycle, and the fourth exposure is delayed by 3/4. Period, the delay value can be preset or external input).

Step 6: The pixel array 1015 exposes the reflected light P1' collected through the lens according to the P2 (01 sequence) signal, and each pixel outputs an exposure value (P3 array).

Step 7: The analog-to-digital converter 1016 digitizes the P3 array signal once to obtain the P4 array, which is transmitted to the ranging circuit 20.

Step 8: After the ranging circuit receives the P4 arrays exposed under different DLL delays, the ranging algorithm is used to obtain the phase delay, and the distance of the object is calculated according to the operating frequency.

Please refer to FIG. 15. FIG. 15 is a schematic diagram of a first pulsed light and a second pulsed light signal provided by an embodiment of the present application; as shown in FIG. 15, it is assumed that the infrared continuous light signal emitted by the light emitter 103 (corresponding to the The transmitted signal, that is, the first pulsed light) is a cosine or square wave signal after passing the modulation, and the signal can be expressed by formula (1). The signal reflected from the target object will produce an offset, partly due to the illumination of the background light; and a modulated cosine signal with phase delay, which is reflected back to the sensor after the transmitted signal illuminates the target scene It is caused by the middle distance; the reflected signal (corresponding to the received signal in the figure, that is, the second pulsed light) can be expressed by formula (2).

s(t)=cos(wt) ⑴

g(t)=1+a*cos(wt-φ) ⑵

By modulating the transmitted signal, the sensor receives and demodulates the signal with phase delay information reflected from the target scene to indirectly obtain the distance information. The distance calculation is shown in formula (3).

In a possible implementation manner, a schematic diagram of the laser emission source, the echo signal (that is, the reflected signal), and the pixel modulation signal can be seen in FIG. 16, which is a square wave signal provided by an embodiment of the present application as an example. Schematic diagram of the signal; as shown in Figure 16, the waveforms of three signals are listed, namely the laser emission source (ie the first pulsed light), the echo signal (ie the second pulsed light) and the pixel modulation signal (used to be processed to the pixel Array input signal). The waveform of the laser emission source is consistent with the waveform and phase of the pixel modulation signal, and the echo signal will cause a certain delay.

In a possible implementation, the device further includes a pixel array 1015 connected to the delay line circuit 1014; each pixel in the pixel array 1015 is used to determine each pixel according to the internal integration switch signals of the multiple pixels and the aforementioned second pulse light. Multiple exposure signals corresponding to one pixel. For the structure of the delay line circuit DLL1014, please refer to FIG. 17. FIG. 17 is a schematic diagram of a DLL structure provided by an embodiment of the present application; the DDL1014 is used to delay the output of the signal by changing the phase, where each τ corresponds to a delay; In the embodiments of the present application, the delay value and times are not limited; after the pulse is input, the input pulse is delayed according to the preset delay value and times, and one or more delay signals are output. For example, the process of TOF ranging and demodulation uses the correlation function method, using the transmitted signal as a reference signal, by obtaining the correlation function between the frequency-modulated transmission signal and the phase-shifted reflected signal after illuminating the target. The calculation is shown in formula (4).

In a possible implementation, the device further includes a delay line circuit 1014 connected to the BPSK modulator 1012; the delay line circuit 1014 is used to perform a phase delay operation on the foregoing first signal according to a preset phase delay value to generate multiple signals. Integrate the switch signal within each pixel. For example, by deriving formula 4, the expression of the correlation function c(τ) can be obtained. Choose 4 different τ value delays: τ ₀ =0°, τ ₁ =90°, τ ₂ =180° and τ ₃ =270° to be substituted into s(t) calculation respectively. The emitted light is a square wave with a certain frequency, and the retroreflected light has the same waveform as the emitted light, but it is delayed by a flight time later. The reference signals inside the Pixel are modulated waveforms C1～C4. These 4 reference signals are cross-correlated and integrated with the retroreflected light. The output results are respectively: Q1～Q4 (Q1 corresponds to formula 5, Q2 corresponds to formula 7, Q3 corresponds to formula 6, Q4 corresponds to formula 8). Considering that the signal returned after reflection may contain background light, an offset K needs to be added to it. After the superposition process, the final expression can be shown in the following formulas (5) to (8).

Using formulas (5) to (8), the phases can be calculated separately

Offset B and amplitude A. Phase delay

Represents the propagation delay of light during flight. When the modulation frequency is set to a fixed value, it is proportional to the distance to the target. Offset B can be used to provide a conventional 2D intensity image and to indicate the amount of charge in the image sensor pixels. Amplitude A represents the achievable depth resolution of direct measurement. The formulas obtained after conversion are shown in equations (9) to (11).

Based on the phase calculated above, the distance D between the camera and the target object can be calculated according to formula (3). Since each pixel of the two-dimensional array image sensor can measure the distance information corresponding to the surface of the target scene, what actually gets is the depth distance image of the surface of the target scene. In order to reconstruct the three-dimensional information in the real scene, further processing of the data is needed. The method adopted in this paper is to first use the camera calibration method to obtain the parameters of the camera, and finally calculate the three-dimensional coordinates according to the principle of small hole imaging combined with the obtained two-dimensional distance map. The obtained formula can be expressed by formulas (12) to (14).

Z _w ＝D (14)

In a possible implementation, the device further includes an analog-to-digital converter ADC1016 connected to the pixel array 1015; the aforementioned ADC is used to convert the aforementioned multiple exposure signals into corresponding multiple digital signals. Further optionally, the foregoing device further includes a ranging circuit 20 connected to the foregoing ADC; the foregoing ranging circuit 20 is configured to receive the foregoing corresponding multiple digital signals; obtaining the phase delay of the foregoing second pulsed light according to the ranging algorithm, The distance between the object to be measured and the anti-interference distance measuring device is calculated according to the frequency of the second pulsed light. For example, when measuring objects in a target scene, the LED modulated light source of the TOF imaging system emits a high-frequency infrared modulation signal to illuminate the target scene, and then the modulation signal is reflected back to the sensor surface to produce a distance-related phase difference. The sensor receives and demodulates the phase difference caused during the flight, and then calculates the distance between the TOF sensor and the target based on known quantities such as the light flight rate and modulation frequency. Optionally, in order to obtain complete three-dimensional information of the target scene and reconstruct the shape of the surface of the object in the target scene through a two-dimensional TOF image sensor array, each pixel in the TOF image sensor array is required to independently receive and demodulate and The distance information or phase difference of the corresponding points on the surface of the object. Finally, every time a TOF imaging system is exposed, the same amount of distance information as the pixel resolution of the sensor image can be obtained, that is, the depth distance image and grayscale image of the target scene. It is understandable that the ranging range is related to the frequency value of the transmitted signal. The farthest distance that can be measured is usually called the fuzzy distance D, D=c/(f*2), where c is the speed of light and f is the frequency, such as 10MHz In the system, the blur distance is 15 meters.

In a possible implementation, the aforementioned device further includes an optical lens (ie, lens 104) connected to the aforementioned pixel array 1015; the aforementioned optical lens 104 is used to receive the aforementioned second pulsed light.

In the embodiment of the present application, a pulse position modulator (that is, a PPM modulator) is added to the ranging chip to reduce the continuous phase of the signal caused by the continuous same random number, which affects the anti-interference ability of the signal. Specifically, the PPM modulator receives the random number signal and the modulation order, and outputs the modulated baseband signal. Through the modulation order, in the case of multiple consecutive identical random numbers that may appear in the random number signal, the phases of consecutive groups of baseband signals in the output baseband signal will not be continuously the same, thereby improving the anti-interference ability of the signal. The operation of randomizing the waveform in the embodiment of this application uses randomized waveforms to transmit and pixel cross-correlation reception. Because random numbers have good auto-correlation and cross-correlation characteristics, the pixel cross-correlation reception will only transmit locally The signal is amplified and output, and other signals will be randomized, which will not cause errors in ranging.

Please refer to FIG. 18, which is a schematic diagram of another TOF ranging principle provided by an embodiment of the present application; in addition to the continuous wave measurement principle, there is also a measurement method based on pulse modulation. As shown in Figure 18, an echo signal is generated after the pulsed light source is illuminated; the pulsed light source is illuminated for a short period of time (Δt), and two inverted windows PH1 and PH2 are used at each pixel, with the same time interval (Δt) ) Sample the reflected energy. Measure the accumulated charges Q1 and Q2 during the sampling process, and use the following formula to calculate the distance:

In the exposure modulation process, according to the actual pixel, system and application requirements, in order to obtain depth of field information, the exposure modulation can be divided into 1, 2, 3, 4 or more times (here, 1 time refers to a set of continuous waveforms). Instead of a periodic waveform). Several typical combinations will be listed below: 1. Continuous wave exposure modulation 4 times; 2. Continuous wave exposure modulation 2 times; 3. Pulse wave exposure modulation 2 times; 4. Pulse wave exposure modulation 1 time. The embodiments of the present application do not limit the number of exposure modulations based on other similar principles. It can be understood that if the pixels are spatially separated, that is, adjacent pixels are exposed to different phases, as long as the principle is the same, it is also included in the protection scope of the embodiments of the present application.

Please refer to FIG. 19, which is a schematic diagram of four continuous wave exposure modulation provided by an embodiment of the present application; as shown in FIG. 19, A ₀ represents an exposure with a phase of 0°, and A ₁₈₀ represents an exposure with a phase of 180°. A ₉₀ represents an exposure with a phase of 90°, and A ₂₇₀ represents an exposure with a phase of 270°. A ₀ A ₁₈₀ means that TapA and TapB are exposed to phases of 0° and 180°, respectively, and A ₁₈₀ A ₀ means that TapA and TapB are exposed to phases of 180° and 0°, respectively. In the schematic diagram, continuous wave A ₀ A ₁₈₀ , A ₉₀ A ₂₇₀ , A ₁₈₀ A ₀ , A ₂₇₀ A ₉₀ and low-frequency continuous wave A ₀ A ₁₈₀ , A ₉₀ A ₂₇₀ are exposed in sequence. In actual operation, the order can be exchanged. In the embodiment of this application, the reason why the order of A ₀ A ₁₈₀ and A ₁₈₀ A _{0 is} reversed during the modulation is mainly because the charge collection capacitor may be different for each TAP, which will affect the accuracy of the system. The chopping technology can Eliminate the mismatch caused by the capacitance (gain error), set voltage, and background light at the charge collection site during reception, and improve the accuracy of depth information.

Please refer to FIG. 20, which is a schematic diagram of two continuous wave exposure modulation provided by an embodiment of the present application; as shown in FIG. 20, A ₀ represents an exposure with a phase of 0°, and A ₁₈₀ represents an exposure with a phase of 180°. A ₉₀ represents an exposure with a phase of 90°, and A ₂₇₀ represents an exposure with a phase of 270°. In actual operation, the order of exposure modulation can be exchanged. A ₀ A ₁₈₀ means that TapA and TapB perform exposure modulation of phase 0° and 180°, respectively, and A ₁₈₀ A ₀ means that TapA and TapB perform exposure modulation of phase 180° and 0°, respectively. In the schematic diagram, the continuous wave A ₀ A ₁₈₀ and A ₉₀ A ₂₇₀ exposures are sequentially performed. In actual operation, the order can be exchanged. The reason why A ₀ A ₁₈₀ and A ₉₀ A _{270 were} exposed during the exposure was mainly to reduce power consumption and increase the frame rate, but because the number of exposures was 2 times less than the method shown in Figure 19, the received The signal strength has also been doubled, so this exposure method will have a higher ranging error. In addition, this example does not use chopping technology to eliminate the misalignment caused by process, device and environmental factors. The accuracy of the depth information will also be mismatched. Relatively lower. In actual operation, the pulse modulation phase of TapA and TapB can be exchanged.

Please refer to FIG. 21. FIG. 21 is a schematic diagram of a pulse wave exposure modulation provided by an embodiment of the present application. As shown in FIG. 21, A ₀ represents an exposure with a phase of 0°, and A ₁₈₀ represents an exposure with a phase of 180°. A ₀ A ₁₈₀ means that TapA and TapB perform phase 0° and 180° exposure modulation respectively, and A ₁₈₀ A ₀ means that TapA and TapB perform phase 180° and 0° exposure modulation respectively. In actual operation, the order can be exchanged. In the embodiment of this application, the reason why the order of A ₀ A ₁₈₀ and A ₁₈₀ A _{0 is} reversed during the modulation is mainly because the charge collection capacitor may be different for each TAP, which will affect the accuracy of the system. The chopping technology can Eliminate the mismatch caused by the capacitance (gain error), set voltage, and background light at the charge collection site during reception, and improve the accuracy of depth information.

Please refer to FIG. 22, which is a schematic diagram of a pulse wave exposure modulation provided by an embodiment of the present application; as shown in FIG. 22, A ₀ represents an exposure with a phase of 0°, and A ₁₈₀ represents an exposure with a phase of 180°. In the embodiments of the present application, the chopping technology is not used to eliminate the imbalance caused by process, device and environmental factors. The accuracy of the depth information will be relatively reduced, but the power consumption will be reduced accordingly. In actual operation, the pulse modulation phase of TapA and TapB can be exchanged.

The specific anti-interference ranging device and application scenarios are described above, and the method embodiments involved in the present application are described below.

Please refer to FIG. 23. FIG. 23 is a schematic diagram of an anti-interference ranging method provided by an embodiment of the present application; the anti-interference ranging method is applied to an anti-interference ranging device (including the aforementioned system architecture). The following will describe from a single side of the transmitting end with reference to FIG. 23. The method may include the following steps S2301-step S2305.

Step S2301: Generate a carrier signal according to a preset period.

Specifically, a carrier signal of a fixed frequency is generated according to a preset carrier generation period, and the carrier signal of the generated fixed frequency is sent to the phase shift keying modulator. Wherein, the phase of the carrier signal and the random number signal are synchronized, so that the carrier signal and the baseband signal generated by the random number signal modulation are processed and the final light source driving signal is output, which is used to finally drive the light emitter to emit pulsed light.

Step S2302: According to the pseudo-random number generation period, the pseudo-random number period and the preset initial pseudo-random number, a plurality of pseudo-random numbers lasting for a preset period of time are generated.

Specifically, in synchronization with the foregoing steps, a plurality of random numbers (or pseudo-random numbers) lasting for a preset period of time are generated according to the pseudo-random number generation period, the pseudo-random number period, and the preset initial pseudo-random number. The foregoing preset duration is the same as the value of the foregoing pseudo-random number generation period. In a possible implementation manner, the aforementioned random number signal includes a plurality of pseudo-random numbers lasting for a preset period of time; the aforementioned method further includes: using a pseudo-random number generator to generate a period, a pseudo-random number period, and a preset period according to the pseudo-random number generator. Set the initial pseudo-random number to generate a plurality of pseudo-random numbers lasting for a preset duration; the aforementioned preset duration is the same as the value of the aforementioned pseudo-random number generation period.

Step S2303: Generate a baseband signal according to the random number signal.

Specifically, the first mapping relationship table corresponding to the first modulation order is determined according to the first modulation order of the multiple modulation orders; and then according to the mapping of each random number in the random number signal in the first mapping relationship table Relation, determine the pulse position of the baseband signal corresponding to each random number, so as to modulate the entire random number signal into a baseband signal. The phases of the two consecutive sets of signals in the aforementioned baseband signal are different; wherein, the aforementioned random number signal includes one or more random numbers, and each random number in the aforementioned random number signal corresponds to a phase of the aforementioned baseband signal, and the aforementioned modulation order The number is used to control the continuous same random number in the random number signal corresponding to the phase of the baseband signal to repeat multiple times; the phase of the random number signal and the baseband signal are synchronized. For example, according to a preset modulation order, determine the mapping relationship between each of the random numbers and the pulse position of the baseband signal; determine that each random number in the random number signal is in the mapping relationship The corresponding pulse position of the baseband signal is modulated into the baseband signal. Continuously, the random number in the random number signal is determined by the pseudo-random number. The random numbers or pseudo-random numbers in the embodiments of the present application have the same functions, and can only be considered to be different from the names, which does not affect the application of the embodiments of the present application.

Optionally, the first modulation order is one of a plurality of preset modulation orders.

Step S2304: The carrier signal and the baseband signal are modulated to generate a first signal.

Specifically, the baseband signal sent by the PPM modulator and the carrier signal sent by the phase-locked loop circuit are received, and the two synchronized signals are processed to generate the first signal (that is, the pulse signal that meets the ranging requirements). The phases of the two consecutive sets of pulse waves in the foregoing multiple sets of pulse waves are different; the foregoing first signal is used to generate the first pulse light, and the foregoing first pulse light is used to illuminate the object to be measured.

In a possible implementation manner, the light emitter is controlled to emit the first pulsed light according to the first signal.

Step S2305: Control the light emitter to emit the first pulsed light according to the first signal.

Specifically, the light source driver receives the first signal; driven by the first signal, the light source driver causes the light emitter to emit the first pulsed light.

It should be noted that the anti-interference ranging method described in the embodiment of the present application can refer to the relevant description of the anti-interference ranging device (transmitting end) in the foregoing device embodiment, and will not be repeated here.

Please refer to FIG. 24, which is a schematic diagram of an anti-interference ranging method provided by an embodiment of the present application; the anti-interference ranging method is applied to an anti-interference ranging device (including the aforementioned system architecture). The following will describe from a single side of the receiving end with reference to FIG. 24. The method may include the following steps S2401-step S2408.

Step S2401: Generate a carrier signal according to a preset period.

Specifically, a carrier signal of a fixed frequency is generated according to a preset carrier generation period, and the carrier signal of the generated fixed frequency is sent to the phase shift keying modulator. Among them, the carrier signal is synchronized with the phase of the random number signal, so that the carrier signal and the baseband signal generated by the random number signal modulation are processed and the final light source driving signal is output, which is used to finally drive the light emitter to emit pulsed light; the aforementioned carrier The signal has the same phase as the aforementioned random number signal.

Step S2402: According to the pseudo-random number generation period, the pseudo-random number period, and the preset initial pseudo-random number, a plurality of pseudo-random numbers lasting for a preset period of time are generated.

Specifically, in synchronization with the foregoing steps, a plurality of random numbers or pseudo-random numbers lasting for a preset period of time are generated according to the pseudo-random number generation period, the pseudo-random number period, and the preset initial pseudo-random number. The foregoing preset duration is the same as the value of the foregoing pseudo-random number generation period. In a possible implementation manner, the aforementioned random number signal includes a plurality of pseudo-random numbers lasting for a preset period of time; the aforementioned method further includes: using a pseudo-random number generator to generate a period, a pseudo-random number period, and a preset period according to the pseudo-random number generator. Set the initial pseudo-random number to generate a plurality of pseudo-random numbers lasting for a preset duration; the aforementioned preset duration is the same as the value of the aforementioned pseudo-random number generation period.

Step S2403: Generate a baseband signal according to the random number signal.

Specifically, the first mapping relationship table corresponding to the first modulation order is determined according to the first modulation order of the multiple modulation orders; and then according to the mapping of each random number in the random number signal in the first mapping relationship table Relation, determine the pulse position of the baseband signal corresponding to each random number, so as to modulate the entire random number signal into a baseband signal. The phases of the two consecutive sets of signals in the aforementioned baseband signal are different; wherein, the aforementioned random number signal includes one or more random numbers, and each random number in the aforementioned random number signal corresponds to a phase of the aforementioned baseband signal, and the aforementioned modulation order The number is used to control the continuous same random number in the random number signal corresponding to the phase of the baseband signal to repeat multiple times; the phase of the random number signal and the baseband signal are synchronized. For example, according to a preset modulation order, determine the mapping relationship between each of the random numbers and the pulse position of the baseband signal; determine that each random number in the random number signal is in the mapping relationship The corresponding pulse position of the baseband signal is modulated into the baseband signal. For detailed description, please refer to the foregoing step S2303, which will not be repeated here.

Step S2404: modulate the carrier signal and the baseband signal to generate a first signal.

Step S2405: Perform multiple phase delay operations on the first signal according to the preset phase delay value to generate multiple internal integration switch signals of the pixels.

Specifically, each of the foregoing multiple phase delay operations corresponds to a pixel internal integration switch signal.

In a possible implementation manner, according to a preset phase delay value, multiple phase delay operations are performed on the first signal to generate multiple pixel internal integration switch signals; each of the multiple phase delay operations Corresponds to the internal integration switch signal of a pixel.

Step S2406: Determine multiple exposure signals corresponding to each pixel according to the internal integration switch signals of the multiple pixels and the second pulse light.

Specifically, after receiving the second pulsed light (the second pulsed light is the pulsed light reflected by the object under test), determine the each of the Multiple exposure signals corresponding to pixels.

Step S2407: Convert multiple exposure signals into multiple corresponding digital signals.

Specifically, according to the exposure signal input of each pixel, the multiple exposure signals of each pixel can be converted into corresponding multiple digital signals through the analog-to-digital converter ADC; and then according to the corresponding calculation method, each digital signal is processed Calculation and processing.

Step S2408: After receiving multiple digital signals corresponding to multiple exposure signals, obtain the phase delay of the second pulsed light according to the ranging algorithm, and calculate the difference between the object under test and the anti-interference ranging device according to the frequency of the second pulsed light. distance.

Specifically, after receiving the corresponding multiple digital signals, the phase of the second pulsed light received by the lens is delayed according to the preset ranging algorithm; and then the target object (that is to be The distance between the object) and the anti-interference distance measuring device.

Optionally, after calculating the distance information on each pixel, what is obtained is the depth image information about the object to be measured. Combining images of other dimensions can restore the distance between the object in the three-dimensional space and the camera, or restore the three-dimensional image of the object.

In a possible implementation manner, the foregoing method further includes: receiving the foregoing second pulsed light through an optical lens.

In a possible implementation manner, the aforementioned light emitter is a light emitting diode LED or a vertical cavity surface emitting laser VCSEL.

In a possible implementation manner, the phases of the aforementioned carrier signal and the aforementioned baseband signal are synchronized.

In a possible implementation manner, the generating the baseband signal according to the random number signal and the first modulation order includes:

According to the corresponding pulse position of each random number in the random number signal in the first mapping relationship table, the random number signal is modulated into the baseband signal, wherein the first mapping relationship table belongs to multiple mappings One of the relationship tables corresponding to the first modulation order; the first modulation order is one of a plurality of preset modulation orders; each of the plurality of mapping relationship tables includes each A mapping relationship between a random number and the pulse position of the baseband signal; the multiple mapping relationship tables have a one-to-one correspondence with the multiple preset modulation orders.

It should be noted that the anti-interference ranging method described in the embodiment of the present application can refer to the related description of the anti-interference ranging device (receiving end) in the foregoing device embodiment, and will not be repeated here.

As shown in FIG. 25, FIG. 25 is a schematic structural diagram of a device provided by an embodiment of the present application. The anti-interference ranging apparatus can be implemented with the structure in FIG. 25. The device 25 includes at least one processor 2501 and at least one memory 2502. In addition, the device may also include general components such as a power supply, which will not be described in detail here.

The processor 2501 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the above program programs.

The memory 2502 may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, random access memory (RAM), or other types that can store information and instructions The dynamic storage device can also be electrically erasable programmable read-only memory (Electrically Erasable Programmable Read-Only Memory, EEPROM), CD-ROM (Compact Disc Read-Only Memory, CD-ROM) or other optical disc storage, optical disc storage (Including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or can be used to carry or store desired program codes in the form of instructions or data structures and can be used by a computer Any other media accessed, but not limited to this. The memory can exist independently and is connected to the processor through a bus. The memory can also be integrated with the processor.

Wherein, the aforementioned memory 2502 is used to store application program codes for executing the above solutions, and the processor 2501 controls the execution. The aforementioned processor 2501 is configured to execute the application code stored in the aforementioned memory 2502.

When the device shown in FIG. 25 is an anti-interference ranging device, the code stored in the memory 2502 can execute the anti-interference ranging method provided in FIG. 23 or FIG. 24 above.

It should be noted that, for the functions of the device 25 described in the embodiments of the present application, reference may be made to the related descriptions in the foregoing apparatus embodiments, and details are not described herein again.

An embodiment of the present application provides an electronic device, which may include the aforementioned anti-interference ranging device, and a discrete device coupled to the outside of the aforementioned anti-interference ranging device.

An embodiment of the present application provides a terminal, the terminal includes a processor, and the processor is configured to support the terminal to perform corresponding functions in the foregoing anti-interference ranging method. The terminal may also include a memory, which is used for coupling with the processor and stores necessary program instructions and data for the terminal. The terminal may also include a communication interface for the terminal to communicate with other devices or communication networks.

The embodiments of the present application also provide a radar, and the aforementioned radar may include the aforementioned anti-jamming ranging device or the aforementioned anti-jamming ranging system for realizing the anti-jamming ranging function provided by the aforementioned device or the aforementioned system. The aforementioned radar may also include a memory coupled to the aforementioned device or the aforementioned system for storing necessary program instructions and data for the radar; the aforementioned radar may also include an external power source coupled to the aforementioned device or the aforementioned system, and the aforementioned external power source is used to supply the aforementioned radar powered by.

An embodiment of the present application provides a vehicle equipped with the aforementioned anti-interference ranging device or the aforementioned anti-interference ranging system for realizing the anti-interference ranging function provided by the aforementioned device or the aforementioned system. The aforementioned vehicle may also include an automatic driving system for controlling the aforementioned vehicle to travel according to road conditions. The aforementioned vehicle may further include an external discrete device coupled to the aforementioned device or the aforementioned system.

In the above-mentioned embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in an embodiment, reference may be made to related descriptions of other embodiments.

It should be noted that for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations, but those skilled in the art should know that this application is not limited by the described sequence of actions. Because according to this application, some steps may be performed in other order or at the same time. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by this application.

In the several embodiments provided in this application, it should be understood that the disclosed device may be implemented in other ways. For example, the device embodiments described above are only illustrative, for example, the division of the above-mentioned units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components can be combined or integrated. To another system, or some features can be ignored, or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical or other forms.

The units described above as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.

In addition, the functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or software functional unit.

If the above integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the technical solution of the present application essentially or the part that contributes to the existing technology or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , Including several instructions to make a computer device (which may be a personal computer, a server, or a network device, etc., specifically a processor in a computer device) execute all or part of the steps of the foregoing methods of the various embodiments of the present application. Among them, the aforementioned storage media may include: U disk, mobile hard disk, magnetic disk, optical disk, read-only memory (Read-Only Memory, abbreviation: ROM) or Random Access Memory (Random Access Memory, abbreviation: RAM), etc. A medium that can store program codes.

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions recorded in the embodiments are modified, or some of the technical features thereof are equivalently replaced; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

An anti-interference ranging device, characterized in that it comprises:

A pulse position modulator, a phase shift keying modulator connected to the pulse position modulator;

The pulse position modulator is used to generate a baseband signal according to a random number signal; wherein the random number signal includes one or more random numbers, and each of the one or more random numbers corresponds to one random number. The pulse position of the baseband signal; when the random number signal has multiple consecutive identical random numbers, there are M pulse positions corresponding to the multiple consecutive identical random numbers in the baseband signal Time interval, M is an integer greater than 0; the phase of the random number signal and the baseband signal are synchronized;

The phase shift keying modulator is used to modulate a carrier signal and the baseband signal to generate a first signal; wherein, the first signal is used to drive a light emitter to generate a first pulsed light, and the first Pulsed light is used to illuminate the object to be measured.
The device according to claim 1, wherein the pulse position modulator is specifically configured to: according to the pulse position of each random number in the random number signal corresponding to the pulse position in the first mapping relationship table, the pulse position modulator The random number signal is modulated into the baseband signal, wherein the first mapping relationship table belongs to one of a plurality of mapping relationship tables corresponding to a first modulation order; the first modulation order is a plurality of presets One of the modulation orders; each of the plurality of mapping relationship tables includes the mapping relationship between each of the random numbers and the pulse position of the baseband signal; the plurality of mapping relationship tables and The multiple preset modulation orders have a one-to-one correspondence.
The device according to claim 1 or 2, wherein the device further comprises a phase locked loop circuit connected with the phase shift keying modulator;

The phase-locked loop circuit is configured to generate the carrier signal according to a preset period, and the carrier signal is synchronized with the phase of the random number signal.
The device according to any one of claims 1-3, wherein the device further comprises: a delay line circuit connected to the phase shift keying modulator;

The delay line circuit is configured to perform multiple phase delay operations on the first signal according to a preset phase delay value to generate multiple pixel internal integration switch signals; each of the multiple phase delay operations corresponds to A switch signal is integrated inside a pixel.
The device according to claim 4, wherein the device further comprises: a pixel array connected to the delay line circuit;

Each pixel in the pixel array is configured to determine a plurality of exposure signals corresponding to each pixel according to the internal integration switch signal of the plurality of pixels and the second pulsed light.
The device according to claim 5, wherein the device further comprises an analog-to-digital converter ADC connected to the pixel array; the ADC is used to convert a plurality of exposure signals corresponding to each pixel into Corresponding multiple digital signals.
The device according to any one of claims 1-6, wherein the device further comprises a pseudo-random number generator connected to the pulse position modulator;

The pseudo-random number generator is configured to generate a plurality of random numbers that last for a preset duration according to a pseudo-random number generation period, a pseudo-random number period, and a preset initial pseudo-random number; the preset duration and the random number The value of the number generation period is the same.
The apparatus according to any one of claims 1-7, wherein the phase of the carrier signal and the baseband signal are synchronized.
An anti-jamming ranging method, which is characterized in that it comprises:

Generating a baseband signal according to a random number signal; wherein the random number signal includes one or more random numbers, and each random number in the one or more random numbers corresponds to a pulse position of the baseband signal; When there are multiple consecutive identical random numbers in the random number signal, there are M time intervals between pulse positions corresponding to the multiple consecutive identical random numbers in the baseband signal, and M is an integer greater than 0 ; The random number signal and the phase of the baseband signal are synchronized;

The carrier signal and the baseband signal are modulated to generate a first signal; wherein, the first signal is used to drive the light emitter to generate first pulsed light, and the first pulsed light is used to illuminate the object to be measured.
The method according to claim 9, wherein the method further comprises: controlling a light emitter to emit the first pulsed light according to the first signal.
The method according to claim 9 or 10, wherein the method further comprises:

The carrier signal is generated according to a preset period, and the phase of the carrier signal is synchronized with the random number signal.
The method according to any one of claims 9-11, wherein the method further comprises:

According to a preset phase delay value, multiple phase delay operations are performed on the first signal to generate multiple pixel internal integration switch signals; each operation in the multiple phase delay operations corresponds to a pixel internal integration switch signal.
The method according to claim 12, wherein the method further comprises:

Receiving a second pulsed light, where the second pulsed light is pulsed light reflected by the object to be measured;

The multiple exposure signals corresponding to each pixel are determined according to the internal integration switch signals of the multiple pixels and the second pulse light.
The method according to claim 13, wherein the method further comprises:

The multiple exposure signals corresponding to each pixel are converted into multiple corresponding digital signals.
The method according to claim 14, wherein the method further comprises:

Receiving the corresponding multiple digital signals;

The phase delay of the second pulsed light is obtained according to a ranging algorithm, and the distance between the object to be measured and the anti-interference ranging device is calculated according to the frequency of the second pulsed light.
The method according to any one of claims 9-15, wherein the method further comprises:

According to the pseudo-random number generation period, the pseudo-random number period, and the preset initial pseudo-random number, a plurality of pseudo-random numbers lasting for a preset duration are generated; the preset duration is the same as the value of the pseudo-random number generation cycle.
The method according to any one of claims 9-16, wherein the phases of the carrier signal and the baseband signal are synchronized.
The method according to any one of claims 9-17, wherein the generating a baseband signal according to a random number signal comprises:

According to the corresponding pulse position of each random number in the random number signal in the first mapping relationship table, the random number signal is modulated into the baseband signal, wherein the first mapping relationship table belongs to multiple mappings One of the relationship tables corresponding to the first modulation order; the first modulation order is one of a plurality of preset modulation orders; each of the plurality of mapping relationship tables includes each A mapping relationship between a random number and the pulse position of the baseband signal; the multiple mapping relationship tables have a one-to-one correspondence with the multiple preset modulation orders.
An anti-interference ranging system, characterized by comprising: a light source driver, a light emitter connected to the light source driver, and the device according to any one of claims 1-8;

The light source driver is configured to control the light emitter to emit the first pulsed light according to the first signal.
The system according to claim 19, wherein the system further comprises an optical lens; the optical lens is used to receive the second pulsed light, and the second pulsed light is a pulse reflected by the object to be measured Light.
The system according to claim 19 or 20, wherein the system further comprises a ranging circuit; the ranging circuit is used for:

Receiving the corresponding multiple digital signals;

The phase delay of the second pulsed light is obtained according to a ranging algorithm, and the distance between the object to be measured and the anti-interference ranging device is calculated according to the frequency of the second pulsed light.
The system according to any one of claims 19-21, wherein the light emitter is a light emitting diode (LED) or a vertical cavity surface emitting laser (VCSEL).
A radar, characterized in that the radar includes the device as claimed in claims 1-8 or the system as claimed in claims 19-21, for realizing the anti-jamming ranging function provided by the device or the system The radar may also include a memory coupled to the device or the system for storing necessary program instructions and data for the radar; the radar may also include an external power supply coupled to the device or the system, so The external power supply is used to supply power to the radar.
A vehicle, characterized in that the vehicle comprises the device according to claims 1-8 or the system according to claims 19-21, for realizing the anti-interference ranging function provided by the device or the system The vehicle may also include an automatic driving system for controlling the driving of the vehicle according to road conditions; the vehicle may also include an external discrete device coupled to the device or the system.
A terminal, wherein the terminal includes a processor configured to support the terminal to perform the corresponding function of the anti-interference ranging method in any one of claims 9-18; the terminal is also It may include the memory, which is coupled with the processor, and is used for storing necessary program instructions and data of the terminal; the terminal may also include a communication interface for communicating through a communication network.