Optical receiving device, receiving processing chip and data processing method

Abstract

The application is suitable for the technical field of detection, and provides an optical receiving device, a receiving processing chip and a data processing method.The optical receiving device comprises a pixel array, a signal processing circuit and a signal output interface, the pixel array comprises a plurality of receiving pixel units, the receiving pixel unit comprises a quenching circuit, an inverting unit, a switching unit and at least two optical receiving devices with different photon detection efficiencies; wherein all the optical receiving devices in the same receiving pixel unit share the quenching circuit and the inverting unit in the receiving pixel unit, and the target optical receiving device is selected through the switching unit; by setting the optical receiving devices with different photon detection efficiencies and selecting the corresponding optical receiving device through the switching unit, the detection capability of the optical receiving device under weak light or for a distant, low-reflectivity object is increased, the saturation in the detection process of a high-reflectivity object under strong light or at a short distance is reduced, the ranging accuracy under strong ambient light is improved, and the dynamic range of the device is effectively improved.

Description

Technical Field

[0001] This application belongs to the field of detection technology, and in particular relates to an optical receiving device, a receiving and processing chip, and a data processing method. Background Technology

[0002] Time-of-flight (TOF) measurement technology has important applications in fields such as autonomous driving, facial recognition, and 3D gesture recognition. In a TOF measurement system, the transmitter emits a pulse signal, and the light receiving device in the light receiving device, such as a single-photon avalanche diode (SPAD), receives the echo light signal, performs photoelectric conversion and avalanche effect to generate a pulse electrical signal. The detector transmits the pulse electrical signal to the sampling circuit, and then obtains histogram data based on the time statistics of the pulse electrical signal recorded by the sampling circuit. The histogram data is then output to the subsequent signal processing unit for processing. The signal processing unit determines the time of flight based on the histogram data, and calculates information such as the distance between the laser and the object based on the time of flight.

[0003] However, existing optical receiving devices suffer from problems such as narrow dynamic range, easy saturation under strong light, and decreased ranging accuracy under strong light. Summary of the Invention

[0004] This application provides a light receiving device, a receiving processing chip, and a data processing method, which can reduce saturation during the detection of objects with high reflectivity, close proximity, and strong light, improve ranging accuracy under strong ambient light, and effectively increase the dynamic range of the device.

[0005] In a first aspect, embodiments of this application provide an optical receiving device, comprising:

[0006] A pixel array, comprising a plurality of receiving pixel units, wherein each receiving pixel unit includes a quenching circuit, an inverting unit, a switching unit, and at least two optical receiving devices with different photon detection efficiencies; wherein all optical receiving devices within the same receiving pixel unit share the quenching circuit and the inverting unit within the receiving pixel unit, and select a target optical receiving device through the switching unit.

[0007] A signal processing circuit, connected to the pixel array, is configured to process the data output by the pixel array;

[0008] A signal output interface is connected to the signal processing circuit and configured to output the data processed by the signal processing circuit.

[0009] In one implementation of the first aspect, the measurement period corresponding to the receiving pixel unit includes a sub-period equal to the number of different types of optical receiving devices with different photon detection efficiencies within the receiving pixel unit. Each sub-period corresponds to an optical receiving device with a photon detection efficiency. Within each sub-period, the optical receiving device corresponding to the sub-period is selected.

[0010] In one implementation of the first aspect, the sub-cycle includes an ambient light acquisition phase and a distance acquisition phase;

[0011] The ambient light acquisition phase is used to acquire the number of photons when the transmitter is not triggered.

[0012] The distance acquisition phase is used to acquire the time from when the transmitter emits a pulse to when the optical receiver receives the echo signal, as well as the number of photons.

[0013] In one implementation of the first aspect, the cathode of the light receiver is connected to the quenching circuit via the switching unit, and the cathode of the light receiver is also connected to the inverting unit. The target light receiver connected to the quenching circuit is controlled by the switching unit.

[0014] In one implementation of the first aspect, the cathode of the optical receiver can be connected to the quenching circuit, and the cathode of the optical receiver is also connected to the inverting unit through the switching unit, thereby controlling the target optical receiver connected to the inverting unit through the switching unit.

[0015] In one implementation of the first aspect, the cathode of the optical receiver is connected to the quenching circuit via the switching unit, and the cathode of the optical receiver is also connected to the inverting unit via the switching unit. The target optical receiver connected to the quenching circuit and the inverting unit is controlled by the switching unit.

[0016] In one implementation of the first aspect, the optical receiving device further includes:

[0017] A pixel control circuit, connected to the switching unit, is configured to control the selection of the target light receiving device.

[0018] Secondly, embodiments of this application provide a receiving processing chip, including an optical receiving device as described in the first aspect or any implementation thereof.

[0019] In one implementation of the second aspect, the receiving and processing chip includes a pixel chip and a circuit chip;

[0020] The light receiving device in the receiving pixel unit is disposed in the pixel chip;

[0021] The quenching circuit of the receiving pixel unit is disposed in the circuit chip.

[0022] Thirdly, embodiments of this application provide a data processing method, including:

[0023] The key information of the target is determined based on the data output by the optical receiving device; the optical receiving device includes a pixel array, the pixel array includes a plurality of receiving pixel units, and the receiving pixel units include at least two optical receiving devices with different photon detection efficiencies.

[0024] The superposition weights of the output results of the optical receiving devices with different photon detection efficiencies are determined based on the key information of the target.

[0025] Based on the superposition weight of the output results of the optical receiving devices with different photon detection efficiencies, the data output by the optical receiving device is fused to obtain the target data.

[0026] The detection results are determined based on the target data.

[0027] In one implementation of the third aspect, the target key information includes the reflectivity information of the object, and the step of determining the superposition weight of the output results of the light receiving devices with different photon detection efficiencies based on the target key information includes:

[0028] The weighting of the output results of the light receiving devices with different photon detection efficiencies is determined based on the reflectivity information of the object. The higher the reflectivity of the object, the higher the weighting of the output results of the light receiving devices with lower photon detection efficiencies; the lower the reflectivity of the object, the higher the weighting of the output results of the light receiving devices with higher photon detection efficiencies.

[0029] In one implementation of the third aspect, the target key information includes the intensity information of the current ambient light, and the step of determining the superposition weight of the output results of the light receiving devices with different photon detection efficiencies based on the target key information includes:

[0030] The superposition weight of the output results of the light receiving devices with different photon detection efficiencies is determined based on the intensity information of the current ambient light. The greater the intensity of the current ambient light, the higher the superposition weight of the output result of the light receiving device with lower photon detection efficiency; the lower the intensity of the current ambient light, the higher the weight of the output result of the light receiving device with higher photon detection efficiency.

[0031] In one implementation of the third aspect, the target key information includes the reflectivity information of the object and the intensity information of the current ambient light. The step of determining the superposition weight of the output results of the light receiving devices with different photon detection efficiencies based on the target key information includes:

[0032] The reflectivity intensity level is determined based on the reflectivity information of the object;

[0033] The ambient light intensity level is determined based on the current ambient light intensity information;

[0034] The superposition weight of the output results of the optical receiving devices with different photon detection efficiencies is determined based on the reflectivity intensity level and the ambient light intensity level.

[0035] Fourthly, embodiments of this application provide a terminal device, which includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the method described in the third aspect or any optional manner of the third aspect.

[0036] Fifthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in the third aspect or any optional manner of the third aspect.

[0037] Sixthly, embodiments of this application provide a computer program product that, when run on a terminal device, causes the terminal device to execute the method described in the third aspect or any optional manner of the third aspect.

[0038] The beneficial effects of the embodiments in this application compared with the prior art are:

[0039] This application provides an optical receiving device, receiving processing chip, data processing method, terminal equipment, computer-readable storage medium, and computer program product. By setting optical receiving devices with different photon detection efficiencies and selecting different optical receiving devices through a switching unit, for example, under weak light illumination, for detecting distant or low-reflectivity objects, an optical receiving device with a higher PDE can be used for detection, while under strong light illumination, for detecting close-range or high-reflectivity objects, an optical receiving device with a lower PDE can be used for reception. This increases the detection capability of the optical receiving device under weak light or for detecting distant, low-reflectivity objects. On the other hand, it can reduce saturation during the detection of close-range, high-reflectivity objects under strong light, improve the ranging accuracy under strong ambient light, and effectively improve the dynamic range of the device. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a circuit diagram of a SPAD pixel unit;

[0042] Figure 2 yes Figure 1 A schematic diagram showing the change of the cathode potential Vc of SPAD11 in the SPAD pixel unit during the avalanche process.

[0043] Figure 3 This is a schematic diagram of the structure of an optical receiving device provided in an embodiment of this application;

[0044] Figure 4 This is a schematic diagram of the structure of a pixel array in an optical receiving device provided in an embodiment of this application;

[0045] Figure 5 This is a schematic diagram of the voltage waveform of the optical receiving device provided in this application within one measurement cycle;

[0046] Figure 6 This is a schematic diagram of the voltage waveform of a sub-cycle in a measurement cycle of the optical receiving device provided in the embodiments of this application;

[0047] Figure 7 This is a circuit diagram of a receiving pixel unit in an optical receiving device provided in an embodiment of this application;

[0048] Figure 8 yes Figure 7 The diagram shows the arrangement of the light receiving devices in the receiving pixel unit.

[0049] Figure 9 This is a schematic diagram of the signal processing circuit in the optical receiving device provided in the embodiments of this application;

[0050] Figure 10 This is a schematic diagram of another optical receiving device provided in an embodiment of this application;

[0051] Figure 11 This is a schematic diagram illustrating the implementation flow of a data processing method provided in an embodiment of this application;

[0052] Figure 12 This is a schematic diagram of the architecture of a receiving and processing chip provided in an embodiment of this application;

[0053] Figure 13 This is a schematic diagram of the structure of a terminal device provided in an embodiment of this application;

[0054] Figure 14 This is a schematic diagram of the structure of a computer-readable storage medium provided in an embodiment of this application. Detailed Implementation

[0055] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0056] It should be understood that the term "and / or" as used in this application specification and the appended claims refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes such combinations. Furthermore, in the description of this application specification and the appended claims, the terms "first," "second," "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0057] It should also be understood that references to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include the specific features, structures, or characteristics described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0058] Time of Flight (TOF) measurement technology has important applications in fields such as autonomous driving, facial recognition, and 3D gesture recognition.

[0059] In a time-of-flight measurement system, the transmitter emits a pulse signal. The optical receiver, such as a single-photon avalanche diode (SPAD), receives the echo signal and performs photoelectric conversion and avalanche effect to generate a pulsed electrical signal. The detector transmits this pulsed electrical signal to a sampling circuit, such as a time-to-digital converter (TDC), which records the time of the pulsed electrical signal. Histogram data is then obtained by statistically analyzing the recorded pulsed electrical signal time and written to a storage unit. This histogram data is then output to a subsequent signal processing unit for further processing. The signal processing unit determines the time of flight based on the histogram data and uses this time to calculate information such as the distance between the laser and the object.

[0060] It is understood that the following embodiments only use SPAD as an example of optical receiving device and are not a limitation. The optical receiving device in this application can also be other types of receiving devices, such as silicon photomultiplier tube (SIPM), etc. This application does not make specific limitations in this regard.

[0061] Please see Figure 1 and Figure 2 , Figure 1 A circuit diagram of a SPAD pixel unit is shown. The SPAD pixel unit 1 includes a SPAD 11, a quenching resistor 12 for quenching the SPAD 11, and an inverter 13. The anode of the SPAD 11 is connected to a negative voltage power supply HV, the cathode of the SPAD 11 is connected to one end of the quenching resistor 12 and the input terminal of the inverter 13, the other end of the quenching resistor 12 is connected to the power supply VDD, and the output terminal of the inverter 13 outputs the pulse signal generated by the SPAD pixel unit 1.

[0062] Figure 2 The diagram illustrates the change in the cathode potential Vc of SPAD11 in the aforementioned SPAD pixel unit 1 during the avalanche process. Before time t1, SPAD11 remains in Geiger mode, with the cathode potential Vc remaining constant at VDD. At time t1, a photon enters SPAD11 and successfully triggers an avalanche. The resulting avalanche current flows through the quenching resistor 12, causing a voltage drop at the SPAD cathode. The cathode potential Vc drops from VDD to approximately 0V, at which point the avalanche process ceases. The power supply VDD then recharges SPAD11 through the quenching resistor 12. After a period of recharging until time t4, the cathode potential Vc of SPAD11 returns to its initial level VDD, and it re-enters Geiger mode.

[0063] The waveform at the output terminal OUT of inverter 13 changes with the cathode potential Vc of SPAD11, similarly as... Figure 2 As shown. During the SPAD11 avalanche, at time t2 when the cathode potential Vc drops below the inverter threshold voltage Vth, the output voltage of inverter 13 reverses from low to high. During the SPAD11 recharging process, the cathode potential Vc begins to recover relatively slowly. At time t3 when the cathode potential Vc rises to the inverter threshold voltage Vth, the output voltage of inverter 13 reverses from high to low. Thus, inverter 13 outputs a complete waveform, where the time span between t2 and t3 is called the output pulse width. Generally, when the number of incident photons is large, the pulse width will broaden to a certain extent. Therefore, the pulse width can also be used to determine the intensity of the echo signal, and thus the reflectivity of the object.

[0064] However, existing optical receiving devices suffer from problems such as narrow dynamic range, easy saturation under strong light, and decreased ranging accuracy under strong light.

[0065] Based on this, embodiments of this application provide an optical receiving device, a receiving processing chip, and a data processing method. By setting optical receiving devices with different photon detection efficiencies and selecting different optical receiving devices through a switching unit, for example, under weak light illumination, or for detecting distant or low-reflectivity objects, an optical receiving device with a higher PDE can be used for detection, while under strong light illumination, or for detecting close-range or high-reflectivity objects, an optical receiving device with a lower PDE can be used for reception. This increases the detection capability of the optical receiving device under weak light or for detecting distant, low-reflectivity objects. On the other hand, it can reduce saturation during the detection of close-range, high-reflectivity objects under strong light, improve the ranging accuracy under strong ambient light, and effectively improve the dynamic range of the device.

[0066] The optical receiving device provided in the embodiments of this application will be described in detail below:

[0067] Please see Figure 3 , Figure 3 The diagram shows a schematic representation of the structure of an optical receiving device 30 provided in an embodiment of this application. It can be understood that... Figure 3 The optical receiving device 30 can be the optical receiving device in the aforementioned time-of-flight measurement system. For example... Figure 3 As shown, the light receiving device 30 may include a pixel array 31, a signal processing circuit 32, and a signal output interface 33.

[0068] Among them, such as Figure 4 As shown, the pixel array 31 may include a plurality of receiving pixel units 311, and each receiving pixel unit 311 may include at least two light receiving devices with different photon detection efficiencies (PDEs), for example... Figure 3 The light receiving device 3111a and light receiving device 3111b, quenching circuit 3112, inverting unit 3113 and switching unit 3114 are included. All light receiving devices in the same receiving pixel unit 311 share the quenching circuit 3112 and inverting unit 3113 in the receiving pixel unit 311, and different light receiving devices are selected through the switching unit 3114 to realize the detection of different light intensities.

[0069] In some embodiments, the cathode of the aforementioned light receiver can be connected to the quenching circuit 3112 via the switching unit 3114, and the cathode of the light receiver can be connected to the inverting unit 3113. The switching unit 3114 controls the light receiver connected to the quenching circuit 3112 (hereinafter referred to as the target light receiver) to select the target light receiver. The anodes of multiple light receivers are connected to the negative voltage power supply HV.

[0070] In some embodiments, the cathode of the aforementioned light receiver can be connected to the quenching circuit 3112, and the cathode of the light receiver can be connected to the inverting unit 3113 via the switching unit 3114. The switching unit 3114 controls the light receiver connected to the inverting unit 3113 (hereinafter referred to as the target light receiver) to select the target light receiver. The anodes of multiple light receivers are connected to the negative voltage power supply HV.

[0071] In some embodiments, the cathode of the aforementioned light receiver can be connected to the quenching circuit 3112 via a switching unit 3114, and the cathode of the light receiver can also be connected to the inverting unit 3113 via a switching device. The switching unit 3114 controls the light receiver connected to the quenching circuit 3112 and the inverting unit 3113 (hereinafter referred to as the target light receiver) to select the target light receiver. The anodes of multiple light receivers are connected to a negative voltage power supply HV.

[0072] In some embodiments of this application, the switch unit 3114 described above may include, but is not limited to, a single-control switch, a double-control switch, etc.

[0073] In some embodiments of this application, the switching unit 3114 may include a gating controller and a switching device connected to the optical receiver. The gating controller controls the on and off states of the switching device connected to the optical receiver to achieve the gating and off of the optical receiver.

[0074] In specific applications, the aforementioned switching devices include, but are not limited to, single-pole switches, double-pole switches, multi-pole switches, and contact switches.

[0075] In practical applications, photon detection efficiency (PDE) is an indicator of a light receiver's ability to detect weak light. A higher PDE indicates a more sensitive light receiver and a greater detection range for the time-of-flight measurement system. However, when detecting highly reflective objects at close range or under strong ambient light, a higher PDE makes the light receiver more prone to problems such as count saturation and high background noise.

[0076] Therefore, the receiving pixel unit 311 in the optical receiving device provided in this application embodiment is equipped with at least two optical receiving devices with different PDEs. By setting optical receiving devices with different PDEs, different optical receiving devices can be selected using a switching unit. For example, in weak light illumination, detection of distant or low-reflectivity objects, an optical receiving device with a higher PDE can be used for detection, while in strong light illumination, detection of close-range or high-reflectivity objects, an optical receiving device with a lower PDE can be used for reception. This increases the detection capability of the optical receiving device in weak light or for distant, low-reflectivity objects. On the other hand, it can reduce saturation during detection of close-range, high-reflectivity objects in strong light, improve ranging accuracy under strong ambient light, and effectively improve the dynamic range of the optical receiving chip.

[0077] In practical applications, when the aforementioned optical receiving device 30 is in operation, for each receiving pixel unit, a measurement cycle corresponding to that receiving pixel unit can be divided into sub-cycles equal to the type of PDE (Physical Component Receiver) of the optical receiving device within that receiving pixel unit 311. Each sub-cycle corresponds to one type of PDE optical receiving device. Within each sub-cycle, the optical receiving device corresponding to that PDE is selected.

[0078] For example, assuming that the receiving pixel unit 311 is equipped with four different PDE optical receiving devices, one measurement cycle of the receiving pixel unit can be divided into four sub-cycles, each sub-cycle corresponding to one type of PDE optical receiving device. Within each sub-cycle, the optical receiving device of the corresponding PDE is selected.

[0079] For example, such as Figure 5 As shown, Figure 5 This is a schematic diagram of the voltage waveform of the optical receiver 30 during one measurement cycle in its operating state. One measurement cycle (frame) can include four sub-frames, namely sub-frame1, sub-frame2, sub-frame3, and sub-frame4. Only one of the four optical receiver devices (taking SPAD as an example) can operate normally within each sub-frame.

[0080] It is understandable that, since the optical receiving devices within the same receiving pixel unit share a quenching circuit, only one type of optical receiving device can work at the same time. Therefore, each sub-cycle corresponds to controlling the operation of one type of PDE optical receiving device.

[0081] Please see Figure 6 , Figure 6The diagram illustrates the voltage waveform for one sub-cycle, where SEL1, SEL2, SEL3, and SEL4 are the enable control signals for SAPD1, SAPD2, SAPD3, and SAPD4, respectively. Specifically, the enable control signals can control the on / off state of the switching devices connected to the SPAD. For example, assuming the enable control signal remains high, the corresponding switching device can be turned on to connect the SPAD controlled by that switching device.

[0082] like Figure 6 In the example shown, SEL1 is at a high level, meaning SPAD1 is enabled; while SEL2, SEL3, and SEL4 remain at a low level, meaning SPAD2, SPAD3, and SPAD4 are disabled. Therefore, it can be understood that in sub-frame 1, only SPAD1 is working normally, while SPAD2, SPAD3, and SPAD4 are all disabled.

[0083] Understandably, the voltage waveforms of other sub-cycles follow the same pattern and will not be elaborated further.

[0084] like Figure 6 As shown, a sub-cycle can be further divided into an ambient light acquisition phase and a distance acquisition phase. In the ambient light acquisition phase, the transmitter is not triggered, meaning it does not emit pulses. At this time, only ambient light causes SPAD 1 to avalanche and output pulses. After passing through a counting circuit, a photon count is obtained, and the count value reflects the current ambient light intensity. In the distance acquisition phase, the transmitter emits pulses multiple times at a certain repetition frequency. The reflected light from the laser pulses hitting the object triggers SPAD 1 to avalanche and output pulse signals. After passing through a TDC circuit, TOF data can be obtained, thus calculating the distance to the object.

[0085] In practical applications, ambient light and dark counts can generate some irrelevant TOF information during the distance acquisition phase. However, after histogram statistics and peak finding, the true TOF information can still be obtained. Specifically, time-correlated single photon counting (TCSPC) can be used to perform the statistics to reduce the influence of ambient light and dark counts.

[0086] In some embodiments of this application, each receiving pixel unit 311 may be equipped with four SPAD devices with significantly different PDEs from low to high.

[0087] It should be noted that the aforementioned significant difference may specifically refer to the case where the difference in PDE is greater than a preset threshold. The preset threshold can be set according to actual needs, and this application does not impose any specific restrictions on it.

[0088] For example, such as Figure 7 As shown, the above-mentioned receiving pixel unit 311 includes 4 SPADs, namely SPAD1, SPAD2, SPAD3 and SPAD4, and the PDE of the 4 SPADs is different. For example, the PDE of SPAD1 to SPAD4 are 10%, 20%, 30% and 40% respectively from low to high.

[0089] like Figure 7 As shown, the cathode of SPAD1 is connected to the quenching resistor R1 via switching device K1a, and is also connected to the inverter U1 via switching device K1b. The cathode of SPAD2 is connected to the quenching resistor R1 via switching device K2a, and is also connected to the inverter U1 via switching device K2b. The cathode of SPAD3 is connected to the quenching resistor R1 via switching device K3a, and is also connected to the inverter U1 via switching device K3b. The cathode of SPAD4 is connected to the quenching resistor R1 via switching device K4a, and is also connected to the inverter U1 via switching device K4b. The anodes of SPAD1, SPAD2, SPAD3, and SPAD4 are all connected to the negative voltage power supply HV.

[0090] When SPAD1 needs to be selected for echo reception, control switches K1a and K1b are closed so that the cathode of SPAD1 is connected to the quenching resistor R1 and the cathode of SPAD1 is connected to the inverter U1 to output the sampling result of SPAD1 (the pulse output by SPAD1d).

[0091] Similarly, when SPAD2 needs to be selected for echo reception, control switches K2a and K2b are closed so that the cathode of SPAD2 is connected to the quenching resistor R1, and the cathode of SPAD2 is connected to the inverter U1 to output the sampling result of SPAD2 (the pulse output by SPAD2), and so on.

[0092] In some embodiments, the plurality of light receiving devices in the receiving pixel unit 311 described above can be arranged according to certain rules, and the arrangement rules can be set according to actual application requirements.

[0093] For example, please refer to Figure 8 ,like Figure 7 The SPADs of the four different PDEs shown in the example can be as follows: Figure 8 Arrange the various possible arrangements shown.

[0094] Understandable Figure 8 This is merely an illustration of the arrangement of four SPADs in a single receiving pixel unit 311, and is not a limitation. The arrangement of multiple optical receiving devices in a receiving pixel unit can be configured according to actual application requirements.

[0095] In some embodiments, the receiving pixel unit 311 may include more or fewer light receiving devices, such as 3 light receiving devices, 6 light receiving devices, etc. The above are merely examples and not limitations.

[0096] In some embodiments, the number of light receiving devices included in different receiving pixel units 311 in the pixel array 31 may be the same or different. The arrangement of the light receiving devices in different receiving pixel units 311 may be the same or different, and can be designed and arranged according to actual application requirements. This application embodiment does not impose specific limitations on this.

[0097] In this embodiment of the application, the signal processing circuit 32 is configured to process the data output by the pixel array 31 to obtain histogram data.

[0098] like Figure 9 As shown, in specific applications, the signal processing circuit 32 described above may include a counting circuit 321 and a timing circuit 322. The counting circuit 321 is used to accumulate and count the output pulses of the optical receiving device; the timing circuit 322 may include a time-to-digital converter (TDC) 3221, a histogram circuit 3222, and a peak finding circuit 3223, used to obtain the time difference between the pulse's emission and its reflection back from the object, i.e., the time of flight (TOF).

[0099] Among them, TDC can record the time of the sampled pulse electrical signal, histogram circuit 3222 can perform histogram statistics based on the time of the sampled pulse electrical signal to obtain histogram data, and peak finding circuit 3223 can perform peak finding based on histogram data to realize functions such as distance measurement and resolution calculation.

[0100] In some embodiments, please refer to Figure 10 , Figure 10 A schematic diagram of the structure of an optical receiving device according to another embodiment of this application is shown. Figure 10 As shown, the light receiving device 30 may further include: a pixel control circuit 34, a light emission timing control circuit 35, and a clock circuit 36.

[0101] The pixel control circuit 34 is configured to control the selection of the target light receiving device; the light emission timing control circuit 35 is used to provide trigger signals to the laser (emitter, not shown in the figure) and timing circuit (not shown in the figure) to achieve synchronization; the clock circuit 36 ​​is used to generate and provide clock signals; and the power supply circuit (not shown in the figure) is used to supply power to the pixel array 31 and other modules.

[0102] As can be seen from the above, the optical receiving device provided in this application embodiment, by setting optical receiving devices with different photon detection efficiencies and selecting different optical receiving devices through a switching unit, for example, under weak light illumination, for distant or low reflectivity object detection, optical receiving devices with higher PDE can be used for detection, while under strong light illumination, for close-range or high reflectivity object detection, optical receiving devices with lower PDE can be used for reception, thereby increasing the detection capability of the optical receiving device under weak light or for distant, low reflectivity objects. On the other hand, it can reduce saturation during the detection of objects under strong light, close-range, and high reflectivity, improve the ranging accuracy under strong ambient light, and effectively improve the dynamic range of the optical receiving chip.

[0103] The optical receiving device provided in the embodiments of this application has been described in detail above. The data processing method provided in the embodiments of this application will now be described in detail with reference to the lidar provided in the above embodiments:

[0104] Please see Figure 11 , Figure 11 This illustration shows a schematic diagram of the implementation flow of a data processing method provided in an embodiment of this application, such as... Figure 11 As shown, the data processing method may include the following steps:

[0105] It should be noted that the execution subject of the data processing method provided in this application embodiment can be a data processing device. The data processing device can be integrated into the same chip as the above-mentioned optical receiving device, or it can be an external processing circuit, such as an FPGA or ASIC. This application does not limit this.

[0106] like Figure 12 As shown, the aforementioned data processing device can communicate with a light receiving device to obtain information about the object's distance, reflectivity, and ambient light intensity from the light receiving device. The data processing device can then perform data fusion processing on the data output by the light receiving device based on this information, thereby improving the accuracy of the detection results.

[0107] In S11, key information about the target is determined based on the data output by the optical receiving device.

[0108] In this embodiment of the application, the aforementioned key target information may be at least one of the following: distance information of the object, reflectivity information of the object, and intensity information of the current ambient light.

[0109] In practical applications, the distance information of the aforementioned object, the reflectivity information of the object, and the intensity information of the current ambient light can be extracted from the data output by the light receiving device. Specifically, the distance information of the object can be obtained based on the aforementioned TCSPC, the reflectivity information can be obtained by evaluating the pulse width broadening corresponding to the histogram data, and the ambient light intensity information can be obtained by photon counting during the aforementioned ambient light acquisition stage.

[0110] In some embodiments, the determination can be based on the photon count of the ambient light acquisition phase of any sub-cycle within a measurement period.

[0111] To obtain more accurate ambient light intensity information, it can also be determined based on the photon counts during multiple sub-cycles within a measurement period. For example, the ambient light intensity information can be determined by averaging the photon counts during multiple sub-cycles within a measurement period.

[0112] In S12, the superposition weight of the output results of different PDE optical receiving devices is determined based on the target key information.

[0113] In some embodiments, the key target information may be the distance information of the object, and the superposition weight of the output results of different PDEs can be determined based on the distance information of the object.

[0114] In some embodiments, the key information of the target can be the reflectivity information of the object. Then, the superposition weight of the output results of light receiving devices with different PDEs can be determined based on the reflectivity information of the object. Specifically, for the case where the reflectivity of the object is higher, the superposition weight of the output results of light receiving devices with lower PDEs is higher, and vice versa.

[0115] In some embodiments, the target key information can be the intensity information of the current ambient light. Then, the superposition weight of the output results of light receiving devices with different PDEs can be determined based on the intensity information of the current ambient light. Specifically, for the case where the ambient light intensity is greater, the output result of the light receiving device with lower PDE will have a higher weight, and vice versa.

[0116] In some embodiments, the superposition weight of different sub-period data (corresponding to the output results of optical receiving devices of different PDEs) can also be determined by the ambient light intensity and the reflectivity of the object.

[0117] In practical applications, ambient light intensity can be divided into two different levels: strong light environment and weak light environment. The reflectivity of objects can be divided into three levels: low, medium and high reflectivity intensity. Then, the superposition weight of the output results of the sub-cycles of the light receiving devices of different PDEs corresponding to different ambient light intensity levels and different reflectivity intensity levels is set and pre-written into the memory contained in the light receiving device 30 or into the memory of the data processing device.

[0118] For example, in combination Figure 7 For a specific example, the relationship between the above superposition weights and ambient light intensity and target reflectivity can be found in Table 1.

[0119] Table 1:

[0120]

[0121] It should be noted that the aforementioned strong light environment can specifically refer to an environment where the ambient light intensity is greater than the first preset intensity threshold, and the weak light environment can specifically refer to an environment where the ambient light intensity is less than the second preset intensity threshold. The first preset intensity threshold and the second preset intensity environment can be set according to the actual application situation, and this application does not impose specific restrictions on them.

[0122] In practical applications, the intensity of the current ambient light can be used to determine whether the environment is weak or strong.

[0123] It is understandable that the classification of ambient light intensity levels can also be based on actual application scenarios. For example, it can be divided into high-intensity light environment, medium-intensity light environment, normal lighting environment, medium-low light environment, and low light environment, etc. The above are just examples and not limitations.

[0124] The threshold for classifying the reflectivity intensity level of the aforementioned object can also be set according to the actual detection situation, and this application does not impose specific restrictions on this. After determining the reflectivity information of the object based on the data output by the light receiving device, the data processing device can determine the reflectivity intensity level of the object based on the reflectivity information.

[0125] After determining the ambient light intensity level based on the current ambient light intensity information and the reflectivity intensity level based on the object's reflectivity information, the superposition weight of the corresponding sub-cycle output results can be determined based on the ambient light intensity level and the reflectivity intensity level.

[0126] For example, assuming the ambient light intensity level is low light environment and the reflectivity intensity level is medium, Table 1 shows that the superposition weight of the output results of the sub-cycle corresponding to the light receiving device with a PDE of 10% is 0%, the superposition weight of the output results of the sub-cycle corresponding to the light receiving device with a PDE of 20% is 25%, the superposition weight of the output results of the sub-cycle corresponding to the light receiving device with a PDE of 30% is 50%, and the superposition weight of the output results of the sub-cycle corresponding to the light receiving device with a PDE of 40% is 25%.

[0127] In some embodiments of this application, a weight allocation model can be obtained through machine learning or large AI models after sufficient training. The trained weight allocation model is then used to analyze the distance information of the object, the reflectivity information of the object, and the ambient light intensity information to determine the superposition weight of the output results of different PDE light receiving devices.

[0128] In S13, based on the superposition weight of the output results of optical receiving devices of different PDEs, the data output by the optical receiving device is fused to obtain the target data.

[0129] In this embodiment, the data fusion processing refers to performing a weighted average of the distance information output from the optical receiving data of different PDEs to obtain the average time of flight (TOF). avg .

[0130] Mean Time of Flight (TOF) avg The formula can be as follows:

[0131] ;

[0132] Where N is the number of sub-periods, TOF i w represents the TOF data acquired in a specific sub-period. i It is the weighting coefficient.

[0133] In S14, the detection results are determined based on the target data.

[0134] In practical applications, the above detection results refer to flight time or object distance information.

[0135] As can be seen from the above, the data processing method provided in this application embodiment can combine key target information to determine the superposition weight of the output results of different PDE optical receiving devices, and perform data fusion of the output results based on the superposition weight, which can effectively improve the accuracy of the detection results.

[0136] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0137] This application also provides a receiving processing chip, including the optical receiving device as described in any of the above embodiments.

[0138] For example, Figure 12 This is a schematic diagram of the structure of the optical receiver chip provided in the embodiments of this application, as shown below. Figure 12 As shown, the optical receiver chip provided in this embodiment can adopt a stacked architecture of two chips, with a pixel chip 81 on top and a circuit chip 82 on the bottom. Both the pixel chip 81 and the circuit chip 82 can be semiconductor chips, connected by copper-copper bonding to form an optical receiver chip. On the pixel chip 81, each receiving pixel unit 311 is arranged into a pixel array 31 according to a certain rule. The quenching circuit 3112 is located on the circuit chip 82 below. One receiving pixel unit 311 corresponds to one quenching circuit 3112.

[0139] It is understandable that the other units / circuits mentioned above can also be set on the circuit chip 82 to achieve the corresponding functions.

[0140] It is also understandable that the receiving and processing chip can adopt other chip architectures, such as monolithic integrated architecture, etc.

[0141] Figure 13 This is a schematic diagram of the structure of a terminal device provided in another embodiment of this application. For example... Figure 13 As shown, the terminal device 100 provided in this embodiment includes: a processor 130, a memory 131, and a computer program 132 stored in the memory 131 and executable on the processor 130, such as an image segmentation program. When the processor 130 executes the computer program 132, it implements the steps in the various data processing method embodiments described above, for example... Figure 11 S11~S14 are shown.

[0142] In one embodiment of this application, the aforementioned terminal device may specifically be a lidar.

[0143] For example, the computer program 132 described above can be divided into one or more modules / units, which are stored in the memory 131 and executed by the processor 130 to complete this application. The one or more modules / units described above can be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program 132 in the terminal device 100.

[0144] The aforementioned terminal device may include, but is not limited to, a processor 130 and a memory 131. Those skilled in the art will understand that... Figure 13 This is merely an example of terminal device 100 and does not constitute a limitation on terminal device 100. It may include more or fewer components than shown, or combine certain components, or different components. For example, the terminal device described above may also include input / output devices, network access devices, buses, etc.

[0145] The processor 130 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0146] The aforementioned memory 131 can be an internal storage unit of the terminal device 100, such as a hard disk or memory of the terminal device 100. The aforementioned memory 131 can also be an external storage device of the terminal device 100, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the terminal device 100. Furthermore, the aforementioned memory 131 can include both internal and external storage units of the terminal device 100. The aforementioned memory 131 is used to store the aforementioned computer program and other programs and data required by the terminal device. The aforementioned memory 131 can also be used to temporarily store data that has been output or will be output.

[0147] This application also provides a computer-readable storage medium. Please refer to... Figure 14 , Figure 14 This is a schematic diagram of the structure of a computer-readable storage medium provided in an embodiment of this application, such as... Figure 14 As shown, a computer-readable storage medium 140 stores a computer program 132, which, when executed by a processor, can implement the above-described data processing method.

[0148] This application provides a computer program product that, when run on a terminal device, enables the terminal device to implement the aforementioned data processing method.

[0149] This application also provides a lidar, which includes the light receiving device described above.

[0150] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the terminal device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0151] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, refer to the relevant descriptions of other embodiments.

[0152] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0153] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. An optical receiving device, characterized by comprising: The application relates to a light receiving device and a data processing method. The light receiving device comprises a pixel array, the pixel array comprises a plurality of receiving pixel units, the receiving pixel units comprise quenching circuits, inverting units, switching units and light receiving devices with at least two different photon detection efficiencies; wherein all the light receiving devices in the same receiving pixel unit share the quenching circuits and the inverting units in the receiving pixel unit and the target light receiving device is selected through the switching unit; the measurement period corresponding to the receiving pixel unit comprises a plurality of sub-periods equal to the number of types of light receiving devices with different photon detection efficiencies in the receiving pixel unit, each sub-period corresponds to a light receiving device with a certain photon detection efficiency, and the light receiving device corresponding to the sub-period is selected in each sub-period; the sub-period comprises an ambient light collection stage and a distance collection stage; the ambient light collection stage is used for collecting the number of photons under the condition that the emitter is not triggered; the distance collection stage is used for collecting the time and the number of photons from the time when the emitter emits a pulse to the time when the echo signal is received by the light receiving device; A signal processing circuit is connected with the pixel array and is configured to perform data fusion processing on the data output by the pixel array. A signal output interface is connected with the signal processing circuit and is configured to output the data processed by the signal processing circuit.

2. The optical receiving device according to claim 1, wherein The cathode of the light receiving device is connected with the quenching circuit through the switching unit, and the cathode of the light receiving device is also connected with the inverting unit; the target light receiving device connected with the quenching circuit is controlled through the switching unit.

3. The optical receiving device according to claim 1, wherein The cathode of the light receiving device is connected with the quenching circuit, and the cathode of the light receiving device is also connected with the inverting unit through the switching unit; the target light receiving device connected with the inverting unit is controlled through the switching unit.

4. The optical receiving device according to claim 1, wherein The cathode of the light receiving device is connected with the quenching circuit through the switching unit, and the cathode of the light receiving device is also connected with the inverting unit through the switching unit; the target light receiving device connected with the quenching circuit and the inverting unit is controlled through the switching unit.

5. The optical receiving device according to claim 1, wherein The light receiving device further comprises: A pixel control circuit is connected with the switching unit and is configured to control the selection of the target light receiving device.

6. A receive processing chip, comprising: The receiving processing chip comprises the light receiving device according to any one of claims 1 to 5.

7. The receive processing chip of claim 6, wherein, The receiving processing chip comprises a pixel chip and a circuit chip; The light receiving device in the receiving pixel unit is arranged in the pixel chip; The quenching circuit of the receiving pixel unit is arranged in the circuit chip.

8. A data processing method, characterized by, The data processing method is realized based on the light receiving device according to any one of claims 1 to 5. Determine target key information according to data output by a light receiving device; the light receiving device comprises a pixel array, the pixel array comprises a plurality of receiving pixel units, the receiving pixel units comprise light receiving devices of at least two different photon detection efficiencies; a measurement period corresponding to the receiving pixel units comprises a number of sub-periods equal to the number of types of light receiving devices of different photon detection efficiencies in the receiving pixel units, each sub-period corresponds to a type of light receiving device of a photon detection efficiency, and in each sub-period, the light receiving device corresponding to the sub-period is controlled to be gated; the sub-period comprises an ambient light collection stage and a distance collection stage; the ambient light collection stage is used to collect the number of photons under the condition that the transmitter is not triggered; the distance collection stage is used to collect the time from when the transmitter emits a pulse to when a return signal is received by the light receiving device and the number of photons; Determine the superposition weight of the output results of the light receiving devices of different photon detection efficiencies according to the target key information; Perform data fusion processing on the data output by the light receiving device based on the superposition weight of the output results of the light receiving devices of different photon detection efficiencies, to obtain target data; Determine a detection result according to the target data.

9. The data processing method according to claim 8, characterized in that, The target key information comprises reflectivity information of an object, and the determination of the superposition weight of the output results of the light receiving devices of different photon detection efficiencies according to the target key information comprises: Determine the superposition weight of the output results of the light receiving devices of different photon detection efficiencies according to the reflectivity information of the object, wherein the higher the reflectivity of the object, the higher the superposition weight of the output results of the light receiving device of lower photon detection efficiency; and the lower the reflectivity of the object, the higher the weight of the output results of the light receiving device of higher photon detection efficiency.

10. The data processing method according to claim 8, characterized in that, The target key information comprises intensity information of current ambient light, and the determination of the superposition weight of the output results of the light receiving devices of different photon detection efficiencies according to the target key information comprises: Determine the superposition weight of the output results of the light receiving devices of different photon detection efficiencies according to the intensity information of the current ambient light, wherein the greater the intensity of the current ambient light, the higher the superposition weight of the output results of the light receiving device of lower photon detection efficiency; and the smaller the intensity of the current ambient light, the higher the weight of the output results of the light receiving device of higher photon detection efficiency.

11. The data processing method according to claim 8, characterized in that, The target key information comprises reflectivity information of an object and intensity information of current ambient light, and the determination of the superposition weight of the output results of the light receiving devices of different photon detection efficiencies according to the target key information comprises: Determine a reflectivity intensity level according to the reflectivity information of the object; Determine an ambient light intensity level according to the intensity information of the current ambient light; Determine the superposition weight of the output results of the light receiving devices of different photon detection efficiencies according to the reflectivity intensity level and the ambient light intensity level.

12. A terminal device, comprising: The terminal device comprises a processor, a memory, and a computer program stored in the memory and executable on the processor, and the processor implements the data processing method of any one of claims 8 to 11 when executing the computer program.

13. A computer program product, characterised in that, When the computer program product is run on the terminal device, the terminal device is caused to perform the data processing method according to any one of claims 8 to 11.

Images