Single-point direct measurement of flight time device and laser ranging system

Abstract

The present application discloses a single-point direct flight time measurement device and a laser ranging system, wherein the device includes a plurality of TDCs arranged in parallel, a plurality of address readout circuits corresponding to each TDC, and a histogram accumulation circuit. The TDC converts the flight time of the light signal corresponding to the target pixel into a digital signal; the Mth TDC outputs the Mth TDC enable signal and the Mth TDC address signal, the Mth TDC enable signal and the Lth TDC address signal are connected to the Mth address readout circuit, and M is not equal to L. The address readout circuit converts the received multiple parallel digital address signals into serial data output; wherein the Mth address readout circuit is used to receive the Mth TDC enable signal and the Lth TDC address signal. The histogram accumulation circuit generates a flight time distribution histogram by accumulating serial data. The present application realizes a true single-point measurement system and effectively prevents user data leakage.

Description

Technical Field

[0001] The present application relates to the field of optoelectronic technologies, and particularly to a single-point direct measurement time-of-flight device and a laser ranging system. Background Art

[0002] In the process of ranging and imaging using a DToF (Direct Time-of-Flight) area array based on SPAD (Single Photon Avalanche Diode) + TCSPC (Time-correlated single-photon counting), it is necessary to form a histogram, and then restore the time-of-flight through signal processing.

[0003] For a single-point measurement system, all pixel units mix the data together and finally output a histogram. To improve the detection performance of the single-point measurement system, usually one or more readout circuits are used to read out multiple SPADs and multiple TDCs (Time to Digital Convert) to achieve the detection of an object. Among them, SPAD is a device that can generate a response current within the ps (picosecond) level. It uses a reverse-biased photodiode and operates within a very small voltage range that exceeds the breakdown voltage but has not yet broken down. At this time, the diode is in a very sensitive working range. Therefore, as long as there is a weak optical signal, it can trigger the generation of an avalanche current, and the response speed is extremely fast. The TDC, through time synchronization with the transmitting end, can generate a current within the ps level when the received optical signal is detected and recorded by the TDC. After N transmissions and receptions, the TDC can record n times (n < N) of the optical time-of-flight and generate a histogram of the time-of-flight distribution, and calculate the time-of-flight value with the highest occurrence frequency as the target value to calculate the distance.

[0004] However, since the pixel unit, TDC, and address readout circuit of the existing single-point measurement system have a fixed correspondence, and on the basis that the single-point measurement system supports the function of selecting SPAD or TDC, when using the single-point measurement system, the user can obtain the histogram of each pixel by opening the pixel unit one by one, and convert the single-point measurement system into a multi-point measurement system. Only one distance value is output under the single-point measurement system, and the user's privacy data will not be leaked. However, after converting it to a multi-point measurement system, the privacy data will be exposed by selecting SPAD and selecting TDC. For scenarios where user privacy needs to be protected, in order to prevent user privacy leakage, it is necessary to control the output of brightness measurement data. The related technology prevents customer privacy leakage by not configuring SPAD on the client or only outputting distance data or statistical histogram data. However, users can still crack the configuration through software to obtain privacy data, and the security performance is not high.

[0005] In view of this, how to realize a true single-point measurement system and solve the disadvantage of the prior art that users convert a single-point measurement system into a multi-point measurement system, thereby causing user data leakage, is a technical problem that technical personnel in the relevant field need to solve. Summary of the invention

[0006] The present application provides a single-point direct measurement flight time device and a laser ranging system, which can realize a true single-point measurement system and prevent users from converting the single-point measurement system into a multi-point measurement system, thereby improving the security of user image data and effectively preventing user data leakage.

[0007] To solve the above technical problems, the embodiments of the present invention provide the following technical solutions:

[0008] An embodiment of the present invention provides a single-point direct flight time measurement device, comprising a plurality of TDCs arranged in parallel, a plurality of address readout circuits corresponding to each TDC, and a histogram accumulation circuit;

[0009] TDC, used to convert the flight time of the light signal corresponding to the target pixel into a digital signal; wherein the Mth TDC outputs the Mth TDC enable signal and the Mth TDC address signal, the Mth TDC enable signal and the Lth TDC address signal are connected to the Mth address readout circuit, and M is not equal to L;

[0010] An address readout circuit is used to convert a plurality of received parallel digital address signals into serial data output; wherein the Mth address readout circuit is used to receive the Mth TDC enable signal and the Lth TDC address signal;

[0011] The histogram accumulation circuit is used to generate a flight time distribution histogram by accumulating the serial data.

[0012] Optionally, the Mth TDC enable signal and the M+1th TDC address signal are connected to the Mth address readout circuit.

[0013] Optionally, the first TDC enable signal and the second TDC address signal are connected to the first address readout circuit, the second TDC enable signal and the third TDC address signal are connected to the second address readout circuit, and the third TDC enable signal and the first TDC address signal are connected to the third address readout circuit.

[0014] Optionally, each address readout circuit is connected to the histogram accumulation circuit.

[0015] Optionally, when in normal detection state, all TDC enable signals are valid;

[0016] When not in the normal detection state, a target TDC enable signal is valid.

[0017] Another aspect of an embodiment of the present invention provides a laser ranging system, including a transmitter, a light collector array, and a single-point direct flight time measurement device as described in any one of the above items;

[0018] The transmitter is used to transmit a light signal to a target object;

[0019] The light collector array is used to receive the light signal reflected by the target object;

[0020] The light collector array includes a plurality of light collectors, and at least one light collector is connected to a TDC of the single-point direct measurement time-of-flight device.

[0021] Optionally, a control module is also included;

[0022] The control module is respectively connected to the emitter, the light collector array and the address readout circuit and the histogram accumulation circuit of the single-point direct flight time measurement device, and is used to output a TDC enable signal.

[0023] Optionally, the control module is further used for:

[0024] When only the target TDC enable signal is detected, the address information of the target TDC is output and an abnormal error instruction is output.

[0025] Optionally, the control module is further used for:

[0026] When a histogram acquisition instruction is received, it is determined whether all TDC enable signals are detected;

[0027] If it is detected that a TDC does not have a corresponding TDC enable signal, an error reporting instruction indicating that the flight time distribution histogram is abnormal is output.

[0028] Optionally, the control module is further used for:

[0029] While generating the error reporting instruction, an intrusion warning message is sent to the target client.

[0030] The advantage of the technical solution provided by the present application is that, by modifying the connection relationship between the TDC address output channel and the corresponding address readout circuit channel, the address of the TDC does not correspond to the channel of the corresponding address readout circuit, so that when the TDC is valid, its corresponding address readout circuit cannot read the address information of the TDC, and the user cannot obtain the histogram of a single pixel by selecting the pixel unit or selecting the TDC based on the correspondence between the pixel unit, TDC, and the address readout circuit, thereby effectively preventing the user from converting the single-point measurement system into a multi-point measurement system, thereby realizing a true single-point measurement system and ensuring that the pixel data is not leaked. The whole process is simple to implement, and this hardware-based encryption method cannot be cracked by software, which can improve the security of user image data, effectively prevent user data leakage, and meet user privacy requirements.

[0031] In addition, the embodiment of the present invention also provides a corresponding laser ranging system for the single-point direct flight time measurement device, which further makes the device more practical, and the laser ranging system has corresponding advantages.

[0032] It is to be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 A schematic diagram of a structural framework of an implementation of a single-point direct flight time measurement device provided by an embodiment of the present invention;

[0035] Figure 2 A schematic diagram of a framework of an existing structure of a device for directly measuring flight time is provided for an embodiment of the present invention;

[0036] Figure 3A schematic diagram of a framework of a single-point direct flight time measurement device provided by an embodiment of the present invention in an exemplary application scenario;

[0037] Figure 4 A structural diagram of a specific implementation of a laser ranging system provided in an embodiment of the present invention;

[0038] Figure 5 A structural diagram of another specific implementation of the laser ranging system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] The terms "first", "second", "third", "fourth", etc. in the specification and claims of this application and the above drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof 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 may include steps or units that are not listed.

[0041] After introducing the technical solutions of the embodiments of the present invention, various non-limiting implementation methods of the present application are described in detail below.

[0042] See first Figure 1 , Figure 1 A schematic diagram of the structural framework of a single-point direct flight time measurement device provided by an embodiment of the present invention in a specific implementation manner, the embodiment of the present invention may include the following contents:

[0043] A single-point direct flight time measurement device may include a plurality of TDCs 11 arranged in parallel, a plurality of address readout circuits 12 corresponding to each TDC, and a histogram accumulation circuit 13.

[0044] The direct measurement time of flight device DTOF can measure the time interval between the transmitted pulse and the received pulse. The core components of DTOF are VCSEL (Vertical Cavity Surface Emitting Laser), single photon avalanche photodiode SPAD and time to digital converter (TDC). DTOF will transmit and receive N optical signals within a single frame measurement time, and then make a histogram accumulation of the N recorded flight times. The flight time with the highest frequency is used to calculate the target distance. For each TDC, it will output the TDC enable signal and TDC address signal to the address readout circuit, such as Figure 2 As shown, the TDC enable signal is Tdc1_valid, Tdc2_valid and Tdc3_valid shown in the figure, and the TDC address signal is Tdc1_address, Tdc2_address and Tdc3_address shown in the figure. The relationship between the pixel unit, TDC and the address readout circuit is one-to-one. The problem is that as long as the chip provides the pixel gating function, including the TDC gating function, a third party or other intruder can obtain spatial distribution information by turning on the pixel units one by one, thereby causing privacy leakage. For example, if a certain pixel is the information needed by the attacker, the attacker can turn off all pixels and then turn on only one pixel at a time. Based on the correspondence between the pixel unit, TDC and the address readout circuit, the corresponding pixel information is found, and the pixel information is leaked. Even if the chip does not provide a gating function, that is, it ensures the single-point feature by not developing it, malicious attackers who can modify the firmware can still obtain image data by modifying the software. Since the pixel unit, TDC and address readout circuit are corresponding, the required information can be easily determined based on the acquired image data.

[0045] In order to solve the above technical problems and ensure that the measurement system is a true single-point measurement system, the statistical histogram can be completely encrypted in space. This application modifies the circuit connection from TDC11 to the address readout circuit 12, thereby hardware encrypting the histogram output, eliminating the spatial distribution characteristics of the SPAD, and the software cannot crack it. In this embodiment, TDC1 is used to convert the flight time of the light signal corresponding to the target pixel into a digital signal. Among them, the Mth TDC outputs the Mth TDC enable signal and the Mth TDC address signal, the Mth TDC enable signal and the Lth TDC address signal are connected to the Mth address readout circuit, and M is not equal to L. In other words, the TDC enable signal and the TDC address signal of the same TDC do not correspond to the same address readout circuit at the same time, or the address information of the TDC and the corresponding address readout circuit channels are not corresponding.

[0046] In this embodiment, the address readout circuit 12 can be used to convert the received multiple parallel digital address signals into serial data output. Among them, the Mth address readout circuit is used to receive the Mth TDC enable signal and the Lth TDC address signal. That is to say, the TDC address signal and the TDC enable signal received by the address readout circuit 12 are not from the same TDC, and multiple TDCs cannot be connected to the channel of the same address readout circuit 12 at the same time. In this way, if only one TDC enable signal is valid, the address readout circuit 12 cannot read the address information of the TDC corresponding to the TDC enable signal, that is, by opening a single pixel unit, the information corresponding to the pixel unit cannot be accurately obtained, thereby ensuring the single-point characteristics of the system. In the embodiment, the number of address readout circuits 12 can be the same as the number of TDCs, that is, one TDC uniquely corresponds to one address readout circuit. Of course, the number of address readout circuits 12 may be less than the total number of TDCs, that is, multiple TDCs correspond to one address readout circuit. However, in this case, in order to ensure the realization of a true single-point measurement system, the number of TDCs corresponding to one address readout circuit cannot be too large.

[0047] The histogram accumulation circuit 13 of this embodiment can be used to generate a flight time distribution histogram by accumulating the serial data output by each address read circuit 12. Each address read circuit 12 can be connected to the histogram accumulation circuit 13. When in a normal detection state, all TDC enable signals are valid, and all TDC data can be output, so that each address read circuit 12 can read the address information from the corresponding TDC based on the received TDC address signal, and the histogram finally generated by the histogram accumulation circuit 13 is valid. When not in a normal detection state, a target TDC enable signal is valid, so that the TDC corresponding to the invalid enable signal cannot obtain the corresponding address information, and the histogram finally output is wrong, realizing a true single-point measurement system to ensure that user data is not leaked.

[0048] by Figure 3For example, if TDC1 is the information needed by the attacker, the attacker will turn off all pixels, and then only open one pixel corresponding to TDC1 at a time. When TDC1 is valid, the corresponding address information is TDC2, not the information TDC1 needed by the attacker. At this time, the obtained statistical histogram is that of TDC2, but the pixel of TDC2 is not turned on, and the address output is abnormal. The address of the abnormal value is not accumulated in the histogram, so the obtained statistical histogram is wrong. If you want to obtain the address information of TDC1, you must get it when TDC3 is valid, but the attacker cannot know the connection relationship between the address of TDC and the address readout circuit, that is, it is impossible to determine the address readout circuit that can read the address of TDC1, so the information is guaranteed to be unbreakable. When multiple pixels are turned on, the TDC enable signal of TDCl is valid, and the data of TDC2 can be obtained. The TDC enable signal of TDC2 is triggered to obtain the data of TDC3, and the TDC enable signal of TDC3 is triggered to obtain the data of TDC 1. When all are set, that is, all TDC enable signals are valid, the histogram output is normal, but the spatial relationship of the histogram is aliased, thereby ensuring that the spatial information is not leaked and protecting user privacy.

[0049] In the technical solution provided by the embodiment of the present invention, by modifying the connection relationship between the TDC address output channel and the corresponding address readout circuit channel, the address of the TDC does not correspond to the channel of the corresponding address readout circuit, so that when the TDC is valid, its corresponding address readout circuit cannot read the address information of the TDC, and the user cannot obtain the histogram of a single pixel by selecting the pixel unit or selecting the TDC based on the correspondence between the pixel unit, TDC, and the address readout circuit, thereby effectively preventing the user from converting the single-point measurement system into a multi-point measurement system, thereby realizing a true single-point measurement system and ensuring that the pixel data is not leaked. The whole process is simple to implement, and this hardware-based encryption method cannot be cracked by software, which can improve the security of user image data, effectively prevent user data leakage, and meet user privacy requirements.

[0050] In the above embodiments, the channel connection relationship between the TDC and the address readout circuit is not limited. In order to make the technical personnel in the relevant field more clearly understand the technical solution of the present application, as an optional implementation method, in order to facilitate implementation and more convenient operation, the present application also provides the following embodiments:

[0051] In this embodiment, the Mth TDC enable signal and the M+1th TDC address signal can be connected to the Mth address readout circuit, that is, each TDC address signal is staggered and output to the adjacent address readout circuit, and the TDC enable signal is also input to the corresponding address readout circuit. For example, the first TDC enable signal and the second TDC address signal are connected to the first address readout circuit, the second TDC enable signal and the third TDC address signal are connected to the second address readout circuit, and the third TDC enable signal and the first TDC address signal are connected to the third address readout circuit. Figure 3 As shown, the TDC enable signal Tdc1_valid of the first TDC circuit, i.e., TDC1, is sent to the first address read circuit, and the TDC address signal Tdc1_address of TDC1 is sent to the third address read circuit; the TDC enable signal Tdc2_valid of the second TDC circuit, i.e., TDC2, is sent to the second address read circuit, and the TDC address signal Tdc2_address of TDC2 is sent to the first address read circuit; the TDC enable signal Tdc3_valid of the third TDC circuit, i.e., TDC3, is sent to the third address read circuit, and the TDC address signal Tdc3_address of TDC3 is sent to the second address read circuit. Of course, in order to increase the complexity of the entire connection relationship and to ensure that the hardware encryption is not cracked to the greatest extent, technicians in the relevant field can adjust the connection method according to actual conditions, which will not affect the implementation of the present application. For example, the Mth TDC enable signal and the M+2th TDC address signal may be connected to the Mth address readout circuit, and the M+2th TDC enable signal and the M+1th TDC address signal may be connected to the M+2th address readout circuit. Of course, for the finished product, in order to reduce the circuit modification cost, for an even number of TDCs, it is possible to simply transpose the TDC address signals of two adjacent TDCs, that is, the Mth TDC enable signal and the M+1th TDC address signal may be connected to the Mth address readout circuit, and the M+1th TDC enable signal and the Mth TDC address signal may be connected to the M+1th address readout circuit.

[0052] Based on the above embodiments, the present application also provides a laser ranging system, such as Figure 4 and Figure 5 As shown, it may include a transmitter 41, a light collector array 42 and a single-point direct measurement time-of-flight device 43 as described in any of the above embodiments.

[0053] The transmitter 41 can be used to transmit an optical signal to a target object. The transmitter 41 can be any single device or a combination of devices that can emit an optical signal, such as Figure 5As shown, the transmitter 42 may include a laser emitting device and a lens. The light collector array 42 includes a plurality of light collectors, which are used to receive the light signal reflected from the target object. At least one light collector in the light collector array 42 is connected to a TDC of the single-point direct flight time measurement device 43. Further, in order to improve the collection efficiency of the reflected light signal, multiple groups of lenses may be arranged between the light collector array 42 and the target object.

[0054] Since the information interaction, execution process and other contents between the units in the system of this embodiment are based on the same concept as those in the above embodiment, the same contents can be found in the description of the above embodiment and will not be repeated here.

[0055] It can be seen from the above that the embodiments of the present invention can improve the security of user image data and effectively prevent user data leakage.

[0056] Furthermore, in order to improve the degree of automation, the above-mentioned laser ranging system may also include a control module 44, which is respectively connected to the address readout circuit 12 and the histogram accumulation circuit 13 of the transmitter 41, the light collector array 42 and the single-point direct measurement flight time device 43, and is used to control the output TDC enable signal.

[0057] In order to improve the user experience, based on the above embodiment, the control module 44 can also be used to: when only the target TDC enable signal is detected, output the error instruction of the abnormal output of the address information of the target TDC. In this embodiment, the target TDC is the TDC corresponding to the target TDC enable signal. Since the TDC address signal and the TDC enable signal of each TDC do not correspond to an address readout circuit at the same time, the address readout circuit that receives the target TDC enable signal cannot obtain the accurate TDC address signal of the target TDC, that is, the read address information is abnormal, and the obtained histogram is also wrong.

[0058] For application scenarios with histogram acquisition requests, in order to ensure that users can obtain accurate histogram information, it is understandable that only when all TDC enable signals are valid can correct histogram information be output. Based on the above embodiment, the control module 44 can also be used to: when receiving a histogram acquisition instruction, determine whether all TDC enable signals are detected; if it is detected that a TDC does not have a corresponding TDC enable signal, then output an error reporting instruction that the flight time distribution histogram is abnormal. If all TDC enable signals are detected, the flight time distribution histogram is obtained from the histogram accumulation circuit 13 and the flight time distribution histogram is output to respond to the histogram acquisition instruction.

[0059] Furthermore, in order to improve the safety performance of the laser ranging system and prevent the leakage of user information in a timely manner, based on the above embodiment, the control module 44 can also be further used to: send intrusion warning information to the target client while generating the error reporting instruction. The target client can be a user terminal pre-registered in the system, and the user terminal is used to receive the alarm information.

[0060] The control module 44 mentioned above is described from the perspective of a functional module. Furthermore, the control module 44 can also be described from a hardware perspective. The control module 44 may include a memory and a processor. The memory is used to store computer programs; the processor is used to execute computer programs to implement the steps of the method involved in the laser ranging process mentioned in any of the above embodiments.

[0061] Among them, the processor may include one or more processing cores, such as a 4-core processor, an 8-core processor, and the processor may also be a controller, a microcontroller, a microprocessor or other data processing chip. The processor may be implemented in at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). The processor may also include a main processor and a coprocessor. The main processor is a processor for processing data in an awake state, also known as a CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in a standby state. In some embodiments, the processor may be integrated with a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor may also include an AI (Artificial Intelligence) processor, which is used to process computing operations related to machine learning. The memory may include one or more computer-readable storage media, which may be non-transitory. The memory may also include a high-speed random access memory and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In some embodiments, the memory may be an internal storage unit of the laser ranging system, such as a hard disk of a server. In other embodiments, it may also be an external storage device of the laser ranging system, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. Further, the memory may also include both an internal storage unit and an external storage device. The memory can be used not only to store application software and various types of data installed in the laser ranging system, but also to temporarily store data that has been output or is to be output.

[0062] In some embodiments, the laser ranging system may further include a display screen, an input / output interface, a communication interface or a network interface, a power supply and a communication bus. Among them, the display screen, the input / output interface such as a keyboard belong to the user interface, and the optional user interface may also include a standard wired interface, a wireless interface, etc. Optionally, in some embodiments, the display may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, and an OLED (Organic Light-Emitting Diode) touch device, etc. The display may also be appropriately referred to as a display screen or a display unit, which is used to display information processed in the laser ranging system and to display a visual user interface. The communication interface may optionally include a wired interface and / or a wireless interface, such as a WI-FI interface, a Bluetooth interface, etc., which are generally used to establish a communication connection between the laser ranging system and other electronic devices. The communication bus may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. Those skilled in the art will appreciate that the laser ranging system may include more or fewer components than those described above, for example, it may also include sensors that implement various functions.

[0063] It is understandable that if the implementation method of the control module 44 in the above embodiment 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 such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art 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 to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), electrically erasable programmable ROM, register, hard disk, multimedia card, card-type memory (such as SD or DX memory, etc.), magnetic memory, removable disk, CD-ROM, disk or optical disk, etc. Various media that can store program codes.

[0064] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. Professionals can also further realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, computer software or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to the function. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0065] The above is a detailed introduction to a single-point direct measurement time-of-flight device and a laser ranging system provided by the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A single-point direct flight time measurement device, characterized in that: It includes a plurality of TDCs arranged in parallel, a plurality of address readout circuits corresponding to each TDC, and a histogram accumulation circuit; TDC, used to convert the flight time of the light signal corresponding to the target pixel into a digital signal; wherein the Mth TDC outputs the Mth TDC enable signal and the Mth TDC address signal, the Mth TDC enable signal and the Lth TDC address signal are connected to the Mth address readout circuit, and M is not equal to L; when in a normal detection state, all TDC enable signals are valid; when not in the normal detection state, a target TDC enable signal is valid; An address readout circuit is used to convert a plurality of received parallel digital address signals into serial data output; wherein the Mth address readout circuit is used to receive the Mth TDC enable signal and the Lth TDC address signal; The histogram accumulation circuit is used to generate a flight time distribution histogram by accumulating the serial data.

2. The single-point direct flight time measurement device according to claim 1, characterized in that: The Mth TDC enable signal and the M+1th TDC address signal are connected to the Mth address readout circuit.

3. The single-point direct flight time measurement device according to claim 2, characterized in that: The first TDC enable signal and the second TDC address signal are connected to the first address readout circuit, the second TDC enable signal and the third TDC address signal are connected to the second address readout circuit, and the third TDC enable signal and the first TDC address signal are connected to the third address readout circuit.

4. The single-point direct flight time measurement device according to claim 1, characterized in that: Each address readout circuit is connected to the histogram accumulation circuit.

5. A laser ranging system, characterized in that: It comprises an emitter, a light collector array and a single-point direct flight time measurement device as claimed in any one of claims 1 to 4; The transmitter is used to transmit a light signal to a target object; The light collector array is used to receive the light signal reflected by the target object; The light collector array includes a plurality of light collectors, and at least one light collector is connected to a TDC of the single-point direct measurement time-of-flight device.

6. The laser ranging system according to claim 5, characterized in that: Also includes a control module; The control module is respectively connected to the emitter, the light collector array and the address readout circuit and the histogram accumulation circuit of the single-point direct flight time measurement device, and is used to output a TDC enable signal.

7. The laser ranging system according to claim 5, characterized in that: Also included is a control module, the control module is further configured to: When only the target TDC enable signal is detected, the address information of the target TDC is output and an abnormal error instruction is output.

8. The laser ranging system according to claim 7, characterized in that: The control module is also used for: When a histogram acquisition instruction is received, it is determined whether all TDC enable signals are detected; If it is detected that a TDC does not have a corresponding TDC enable signal, an error reporting instruction indicating that the flight time distribution histogram is abnormal is output.

9. The laser ranging system according to claim 8, characterized in that: The control module is also used for: While generating the error reporting instruction, an intrusion warning message is sent to the target client.

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