Detection method, detection control apparatus, chip, lidar, and terminal

Abstract

A detection method, a detection control apparatus (11, 170, 180), a chip, a LiDAR, and a terminal, applied to the technical field of detection. Test pixels are provided in an array detector (12), the test pixels can collect measurement data indicating deadtime information, and circuit parameters of target pixels can be adjusted on the basis of the measurement data and deadtime target values. Moreover, the circuit parameter adjustment can change the performance of detection elements (121) in the array detector (12), so that the deadtimes of the target pixels can change in a direction close to the corresponding deadtime target values, thereby implementing dynamic correction of the deadtime of the array detector (12), improving the stability of the deadtimes of the detection elements (121) under different PVT conditions, and ensuring the performance stability of a detection apparatus (10).

Description

A detection method, detection control device, chip, lidar, and terminal

[0001] This application claims priority to Chinese Patent Application No. 202410798889.6, filed on June 19, 2024, entitled "A Detection Method, Detection Control Device, Chip, LiDAR and Terminal", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of detection technology, and in particular to a detection method, detection control device, chip, lidar, and terminal. Background Technology

[0003] With the rapid advancements in information technology and computer vision, detection technology has developed at an unprecedented pace, bringing immense convenience to people's production and daily lives through a wide variety of detection devices. These devices act as the "eyes" for equipment to perceive its environment, including visual sensors such as cameras and radar sensors such as lidar, millimeter-wave radar, and ultrasonic radar. Among these, lidar (light detection and ranging, LiDAR) offers significant advantages in detection range, ranging accuracy, and reliability, and its near-all-weather operation makes it a key sensor in the field of perception, playing a crucial role in areas such as intelligent driving, intelligent transportation, surveying and mapping, and intelligent manufacturing.

[0004] Before application, LiDAR requires process verification testing (PVT) to verify its stable performance under different PVT scenarios. Single-photon avalanche diodes (SPADs) are widely used in LiDAR as high-sensitivity detectors. After receiving a light signal, the SPAD generates an avalanche current with a certain detection probability, enters a quenching process, and then recharges and resets. The time period between the quenching process and the SPAD's recharge and reset is called the SPAD's dead time. The parameters of the SPAD's dead time, such as the duration of the dead zone, affect the detection data output by the SPAD, such as the maximum count value of the echo signal and the echo area, and also affect the LiDAR's estimation of the target echo's starting position and echo energy. The SPAD's dead time is often affected by factors such as changes in ambient temperature and light intensity, resulting in inconsistent dead times under different PVT conditions, thus affecting the performance stability of the LiDAR.

[0005] Improving the stability of the dead time of SPAD under different PVT conditions and ensuring the stability of LiDAR performance is a hot topic of research in the field. Summary of the Invention

[0006] This application provides a detection method, detection control device, chip, lidar, and terminal, which can improve the stability of the dead time of the detection element under different PVT conditions and ensure the stable performance of the detection device.

[0007] In a first aspect, this application provides a detection method, comprising: acquiring first measurement data of a first test pixel in an array detector, and adjusting circuit parameters of a detection element in a first target pixel based on the first measurement data and a first dead-time target value. The array detector includes multiple pixels, each pixel including at least one detection element, and both the first test pixel and the first target pixel belong to the multiple pixels, with the first target pixel including at least the first test pixel. The first measurement data is used to indicate the dead-time information of the first test pixel, such as including the duration of multiple dead times, or including the number of dead-time triggers and the total length. The circuit of the detection element is used to drive the detection element to operate, and the dead time of the first target pixel can be adjusted by adjusting the circuit parameters.

[0008] Optionally, this detection method can be applied to a detection control device, for example, executed by modules (including software modules and / or hardware modules) within the detection control device. For ease of description, the following explanation uses the detection control device as the executing entity.

[0009] In the application, a test pixel (taking the first test pixel as an example) is set in the array detector. The test pixel can collect measurement data indicating dead time information. This measurement data reflects the dead time of the test pixel in the array detector under the current environmental conditions. The detection control device can acquire the measurement data of the test pixel and adjust the circuit parameters in the first target pixel based on the measurement data and the first dead time target value. The circuit parameter adjustment can change the performance of the detection element in the array detector, so that the dead time of the first target pixel can change in a direction closer to the first dead time target value.

[0010] Thus, based on the first test data, the current measured value of the dead time can be determined. By combining the measured value of the dead time with the first target value of the dead time and adjusting the circuit parameters, dynamic correction of the dead time of the array detector can be achieved. Under different PVT conditions, the closed-loop control scheme of detection, feedback, and correction provided in this application can improve the stability of the dead time of the detection element and ensure the stable performance of the detection device.

[0011] Optionally, the detection element may include one or more of the following: SPAD, silicon photomultiplier (SiPM), avalanche photo detector (APD), multi-pixel photon counter (MPPC), or electron multiplying charge-coupled device (EMCCD).

[0012] In one possible implementation of the first aspect, the circuit connected to each probe element includes a first voltage input terminal, a second voltage input terminal, a quenching resistor, and an inverter. The first and second voltage input terminals supply power to the corresponding probe element, the quenching resistor divides the voltage for the corresponding probe element, one end of the inverter is connected to the corresponding probe element, and the other end is connected to the readout circuit of the corresponding probe element. Optionally, the readout circuit outputs the measurement data of the probe element.

[0013] The circuit parameters include one or more of the following: the voltage value of the first voltage input terminal, the voltage value of the second voltage input terminal, the resistance value of the quenching resistor, and the threshold voltage of the inverter, etc.

[0014] In another possible implementation of the first aspect, the first test pixel is located in a first region of the array detector, where the received light energy density is less than a preset value, or the received light energy density of the first region is less than the received light energy density of a second region in the array detector.

[0015] Under strong light conditions, multiple detector elements within a pixel may trigger avalanches in succession, making it impossible to accurately determine the dead time of a single detector element. In the above embodiment, the test pixel can be located in the low-light or no-light area of ​​the array detector, enabling the measurement data collected by the test pixel to more accurately reflect the dead time of the detector element, improving the accuracy of the dead time measurement value, and thus improving the accuracy of dead time adjustment.

[0016] In another possible implementation of the first aspect, the first target pixel further includes a main pixel in an array detector, the main pixel of the array detector being used for target detection, and the main pixel and the first test pixel being located in different regions of the array detector.

[0017] In the above embodiments, separating the main pixel and the test pixel isolates the test area and the detection area, facilitating additional design of the test pixel without affecting the target detection of the array detector. For example, the test pixel can be designed with a smaller aperture or its counting method can be changed, which can improve the accuracy of the dead time measurement, thereby improving the accuracy of the rise-dead time adjustment.

[0018] In another possible implementation of the first aspect, the first test pixel includes a dark pixel. The dark pixel acquires data using a dark counting method. In the above implementation, under the dark counting method, the probability of a detector element in a pixel triggering an avalanche is relatively low, and the probability of multiple detector elements in a pixel triggering an avalanche simultaneously is even lower. This allows the measurement data acquired by the test pixel to more accurately reflect the dead time of a single detector element, improving the accuracy of the dead time measurement value and thus improving the accuracy of dead time adjustment.

[0019] In another possible implementation of the first aspect, the first test pixel includes a pixel whose aperture is smaller than the length of the photosensitive surface of the pixel, the aperture being used to control the amount of light entering the pixel. In other words, the first test pixel includes a pixel whose aperture area is smaller than the area of ​​the photosensitive surface of the pixel.

[0020] In another possible implementation of the first aspect, the first test pixel is also used for target detection. In the above implementation, the test pixel is also used for target detection. For example, the data collected by the test pixel is used to obtain both the measurement value of the dead time and the detection results of the object space, such as obtaining one or more of the following information: time offlight (TOF) value, distance to the point and the target, position of the target, angle of the target, speed of the target, and reflection intensity of the target.

[0021] In the above embodiments, the pixels in the array detector can perform both target detection and target testing. The pixels in the array detector are more practical, and the measurement data of the test pixels can more accurately reflect the dead time of the main pixel area.

[0022] In another possible implementation of the first aspect, adjusting the circuit parameters of the detection element in the first target pixel based on the first measurement data and the first dead time target value includes: determining the measured value of the dead time of the first test pixel based on the first measurement data, determining the first compensation amount based on the measured value of the dead time of the first test pixel and the first dead time target value, and adjusting the circuit parameters of the detection element in the first target pixel based on the first compensation amount.

[0023] In the above implementation, the compensation amount reflects the difference between the measured value and the target value of the dead time. Based on the compensation amount, the dead time of the detection element can be compensated and corrected to be closer to the target value, thereby improving the stability of the dead time of the array detector under different PVT conditions and ensuring the stable performance of the detection device.

[0024] In another possible implementation of the first aspect, determining a first compensation amount based on the measured value of the dead time of the first test pixel and a target value of the first dead time includes: determining the first compensation amount using a proportional-integral-differential (PID) method based on the measured value of the dead time of the first test pixel and the target value of the first dead time.

[0025] Among them, the PID algorithm is a feedback control algorithm that can calculate and process the difference between the measured value and the target value of the controlled object, and adjust the value of the controlled object to make it approach the target value. In the above implementation, the PID algorithm can adjust the dead time of the target pixel towards the first dead time target value, which can improve the stability of the dead time of the array detector under different PVT conditions and ensure the stable performance of the detection device.

[0026] In another possible implementation of the first aspect, determining a first compensation amount based on a measured value of the dead time of the first test pixel and a target value of the first dead time includes: determining an adjustment granularity based on the difference between the measured value of the dead time of the first test pixel and the target value of the first dead time; and determining the first compensation amount based on the adjustment granularity and a bias value, wherein the bias value is predefined.

[0027] The above implementation provides another calculation process for a feedback control algorithm. Based on the difference between the measured value and the first dead time, the granularity of the adjustment can be determined. This granularity reflects the magnitude of the adjustment, and can include both coarse and fine adjustments. When the difference is large, the adjustment granularity is coarse; when the difference is small, the adjustment granularity is fine. Based on the adjustment granularity and a preset bias value, a compensation amount is output to adjust the value of the controlled object to approach the target value.

[0028] Optionally, the adjustment granularity can be determined using a dichotomy method. For example, if the difference exceeds half the target value of the dead time, the adjustment granularity is coarse. If the deviation does not exceed half the dead time, the adjustment granularity is fine. Of course, different adjustment granularities can be designed for various cases where the difference exceeds one-half, one-quarter, one-eighth, etc.

[0029] In another possible implementation of the first aspect, the detection method further includes: acquiring second measurement data from the second test pixel, and determining a second dead-time compensation amount based on the second measurement data and a second dead-time target value. The second test pixel also belongs to multiple pixels, and the second measurement data is used to indicate the dead-time information of the second test pixel. The first dead-time target value is a dead-time target value corresponding to the first environmental condition, and the second dead-time target value is a dead-time target value corresponding to the second environmental condition.

[0030] In the above embodiments, different environmental conditions can correspond to different target values ​​for dead time. For example, different target values ​​can be used under high temperature and low temperature conditions. Similarly, different target values ​​can be used under strong light and dark conditions. Thus, based on multiple different target values ​​for dead time, multiple different compensation amounts can be calculated for selection during adjustment, making the dead time adjustment compatible with the current operating environment of the detection device and improving the detection performance of the device.

[0031] Optionally, the target dead time value can be predefined or pre-set. For example, the array detector can be simulated and tested in a laboratory environment to determine the dead time value that enables the array detector to achieve optimal detection performance under different environmental conditions, which can be used as the target dead time value under that environmental condition.

[0032] In another possible implementation of the first aspect, the detection method further includes: determining, based on environmental information, a first dead-time compensation amount and a second dead-time compensation amount, wherein the first dead-time compensation amount is used to adjust the parameters of the front-end circuit of the detection element in the first target pixel.

[0033] Since the first and second dead-time target values ​​correspond to different environmental conditions, when determining the compensation amount used to adjust the front-end circuit, the current environmental conditions can be determined based on environmental information, thereby selecting the corresponding compensation amount for adjustment. In the above implementation, the first compensation amount can be determined as the compensation amount used for adjustment based on environmental information; that is, the current environment is determined to belong to the first environmental condition based on environmental information.

[0034] In another possible implementation of the first aspect, the first test pixel and the second test pixel are located in different regions of the array detector. In this manner, the first test pixel and the second test pixel are different; that is, multiple sets of test pixels can be set to obtain multiple compensation amounts corresponding to different environmental conditions.

[0035] In another possible implementation of the first aspect, the first test pixel and the second test pixel are located in the same area of ​​the array detector, but the acquisition times of the first and second measurement data are different. In this implementation, the first and second test pixels are the same group of pixels, but multiple sets of measurement data are acquired in a time-division manner. Based on the multiple sets of measurement data and multiple sets of target values, multiple compensation amounts corresponding to different environmental conditions are obtained. The time-division method reduces the detector space occupied by the test pixels, which can reduce the manufacturing cost of the array detector and facilitate the miniaturization design of the detection device.

[0036] In another possible implementation of the first aspect, the first test pixel is the same as the second test pixel, and the first measurement data is the same as the second measurement data. In this implementation, the same set of measurement data for the same set of pixels can be combined with different target values ​​to obtain multiple compensation amounts corresponding to different environmental conditions.

[0037] In another possible implementation of the first aspect, the first measurement data is used to indicate the photon count for each dead time of the first test pixel and the trigger number of the dead time of the first test pixel, wherein the maximum value of the photon count of the dead time of the first test pixel is lower than a preset counting threshold, and / or the trigger number of the dead time of the first test pixel reaches a statistical threshold.

[0038] In the above implementation, the first measurement data satisfies the validity condition, which restricts one or more of the maximum value of the photon count of the dead time and the trigger number of the dead time in the measurement data. Designing the validity condition can improve the accuracy of the dead time measurement value, thereby improving the accuracy of the dead time adjustment.

[0039] In another possible implementation of the first aspect, the detection method further includes: acquiring third measurement data from the third test pixel and detecting the validity of the third measurement data. If the third measurement data is invalid, measurement data from a fourth test pixel is acquired, wherein the fourth test pixel has a different aperture than the third test pixel and / or the fourth test pixel has a different binning method than the third test pixel. The third test pixel belongs to multiple pixels, and the fourth test pixel also belongs to multiple test pixels.

[0040] In some schemes, the third and fourth test pixels can be located in different regions, corresponding to two different sets of detection elements. In this scheme, the fourth test pixel has a different aperture than the third test pixel, or the binning methods of the third and fourth test pixels are different.

[0041] In other schemes, the third and fourth test pixels can be located in the same area, or their areas on the array detector can overlap; for example, the third and fourth test pixels may correspond to some of the same detection elements. In this scheme, the binning methods of the third and fourth test pixels are different.

[0042] In the above implementation, the measurement data undergoes validity testing before use. If the current measurement data is invalid, the pixel binning method can be adjusted through feedback, and / or pixels with different aperture sizes can be selected to ensure the validity of the acquired measurement data.

[0043] In another possible implementation of the first aspect, the third measurement data is used to indicate the photon count for each dead time of the third test pixel and the trigger count for the dead time of the third test pixel. The third measurement data is valid if one or more of the following conditions are met, otherwise the third measurement data is invalid: Condition 1, the maximum value of the photon count for the dead time of the third test pixel is lower than a preset counting threshold; Condition 2, the trigger count for the dead time of the third test pixel reaches a statistical threshold.

[0044] Alternatively, validity testing may only examine one of the conditions, such as condition 1 or condition 2. Or alternatively, the measurement data is valid if both condition 1 and condition 2 are met simultaneously.

[0045] Secondly, this application provides a detection control device. The detection control device includes an acquisition unit and a processing unit, and is used to implement the method described in the first aspect or any possible embodiment of the first aspect. The acquisition module is used to perform one or more operations such as acquisition, reception, or conversion. The processing module is used to perform one or more operations such as adjustment, determination, processing, calculation, or detection.

[0046] Thirdly, this application provides a detection control device, which includes a processor and a memory. The memory is used to store computer instructions, and the processor is used to call the computer instructions stored in the memory, so that the detection device implements the method described in the first aspect or any possible implementation of the first aspect.

[0047] Optionally, the aforementioned detection and control device may be the processing module and / or control module in a lidar.

[0048] Fourthly, this application provides a chip including a processor and a communication interface, the communication interface being used for inputting / or outputting information, and the processor being used for executing computer instructions to implement the method described in the first aspect or any possible implementation of the first aspect.

[0049] Fifthly, this application provides a lidar system, including a transmitting module and an array detector, and further including the detection control device described in the third or fourth aspect or the chip described in the fifth aspect. The array detector includes multiple pixels, each pixel including at least one detection element, and each detection element connected to a corresponding circuit. The transmitting module is used to transmit a light beam, and the array detector is used to receive the echo of the light beam and output measurement data.

[0050] In a sixth aspect, this application provides a terminal, which includes the detection and control device described in the third or fourth aspect, or the chip described in the fifth aspect, or the lidar described in the sixth aspect.

[0051] Optionally, the terminal can be a smart terminal or means of transportation such as a vehicle, drone, or robot.

[0052] The beneficial effects of aspects two through six of this application may be referenced to the beneficial effects of aspect one. Attached Figure Description

[0053] The accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0054] Figure 1 is a schematic diagram of a detection device provided in an embodiment of this application;

[0055] Figure 2 is an equivalent circuit diagram of a detection element and its connected circuit provided in an embodiment of this application;

[0056] Figure 3 is a flowchart illustrating a detection method provided in an embodiment of this application;

[0057] Figure 4 is a schematic diagram of the pixel distribution of an array detector provided in an embodiment of this application;

[0058] Figure 5 is a schematic diagram of the pixel distribution of another array detector provided in an embodiment of this application;

[0059] Figure 6 is a schematic diagram of five types of test pixels provided in the embodiments of this application;

[0060] Figure 7 is a schematic diagram of the dead time of a test pixel provided in an embodiment of this application;

[0061] Figure 8 is a schematic diagram of the dead time of a pixel provided in an embodiment of this application;

[0062] Figure 9 is a schematic diagram of the operation process of a detection method provided in an embodiment of this application;

[0063] Figure 10 is a schematic diagram of the operation process of another detection method provided in the embodiment of this application;

[0064] Figure 11 is a schematic diagram of a method for controlling the dead time of a pixel according to an embodiment of this application;

[0065] Figure 12 is a schematic diagram of another method for controlling the dead time of a pixel provided in an embodiment of this application;

[0066] Figure 13 is a schematic diagram of a multi-level dead time adjustment method provided in an embodiment of this application;

[0067] Figure 14 is a schematic diagram of another method for adjusting dead time in multiple positions according to an embodiment of this application;

[0068] Figure 15 is a schematic diagram of another method for adjusting dead time in multiple positions according to an embodiment of this application;

[0069] Figure 16 is a schematic diagram of another method for adjusting dead time in multiple positions according to an embodiment of this application;

[0070] Figure 17 is a schematic diagram of a detection control device provided in an embodiment of this application;

[0071] Figure 18 is a schematic diagram of another detection and control device provided in an embodiment of this application. Detailed Implementation

[0072] The following section will introduce some of the technical terms used in this application.

[0073] Dead time is the time from the onset of an avalanche effect to the end of charging and resetting for a detection element. When the detection element is operating, the voltage across its terminals is above its breakdown voltage. After absorbing a photon, the detection element generates an avalanche effect. The continued avalanche effect can generate a large current that burns out the device and hinders subsequent photon detection. Therefore, the detection element is usually connected to a quenching circuit. After the avalanche current is generated, the quenching circuit divides the power supply current, pulling the voltage across the detection element below the breakdown voltage. After the quenching process, the intensity of the electric field inside the detection element weakens, and the avalanche effect ends. After the quenching process, the power supply begins to charge and reset the detection element, restoring the voltage across its terminals to above the breakdown voltage, preparing it for the next photon detection.

[0074] Binning is an image readout mode that, when reading data from detector elements, adds the outputs of adjacent detector elements together and outputs (or reads out) them as a single pixel. The number of detector elements corresponding to a single pixel is called the binning value. For example, when the outputs of 16 detector elements in a 4x4 array are added together as a single pixel, the binning value for that pixel is 16.

[0075] A detection device is a device for detecting targets in an object space. Its working principle involves emitting a detection signal into the object space, receiving a return signal from the object space, and obtaining relevant information about the target in the object space based on the return signal. This information may include one or more of the target's distance, position, angle, speed, reflectivity, reflection intensity, color, or material. The detection signal is typically an electromagnetic wave or sound wave. Electromagnetic waves include light, millimeter waves, or centimeter waves. The detection device provided in this application embodiment can use light as the detection signal, such as a lidar, or a fusion sensing device that includes a light detection device (e.g., a device that integrates lidar and a camera).

[0076] The detection device provided in this application will be introduced below. It should be noted that the architecture and application scenarios of the device described in this application are for the purpose of more clearly illustrating the technical solution of this application, and do not constitute a limitation on the technical solution provided in this application. As those skilled in the art will know, with the evolution of architecture and the emergence of new business scenarios, the technical solution provided in this application is also applicable to similar technical problems.

[0077] Please refer to Figure 1, which is a schematic diagram of a detection device provided in an embodiment of this application. The detection device 10 includes an array detector 12 and a detection control device 11. Wherein:

[0078] The array detector 12, also known as a planar array detector, is used to receive a light beam and obtain measurement data. The array detector 12 includes multiple detection elements 121 arranged in rows and columns. The detection elements 121 include, but are not limited to, one or more of the following: SPAD, SiPM, APD, MPPC, or EMCCD. For example, the detection element 121 can be a SPAD, in which case the array detector is a SPAD array detector. It should be understood that the shape, arrangement, and number of detection elements shown in this application are merely examples.

[0079] When the detection element 121 is in operation, a voltage needs to be applied to it through a circuit to drive it. This circuit is also called the driving circuit of the detection element, or the front-end circuit. Referring to Figure 1, each detection element 121 is connected to a corresponding circuit 122, which includes at least two ports for applying voltage to the detection element 121. For ease of understanding, Figure 2 shows an equivalent circuit diagram of a detection element and its connected circuit. The circuit includes a first voltage input terminal (Vop), a second voltage input terminal (Vex), a quenching resistor (Rq), and an inverter (threshold voltage Vth). The first and second voltage input terminals supply power to the detection element, the quenching resistor divides the voltage for the corresponding detection element, one end of the inverter is connected to the corresponding detection element, and the other end is connected to the readout circuit of the corresponding detection element. For example, the first voltage input terminal is connected to one end of the detection element, and the other end of the detection element is connected to the quenching resistor and the inverter. Changing the parameters of the circuit connected to the detection element will cause a change in the performance of the detection element. For example, changing one or more of the voltage values ​​at the first voltage input terminal, the second voltage input terminal, the structure of the quench resistor, or the threshold voltage of the inverter will cause a change in the dead time of the detection element.

[0080] The detection control device 11 is a device with control and computing capabilities. The detection control device 11 can be connected to the array detector 12, or it can be disposed within the array detector 12. The detection control device 11 can acquire and process data from the array detector 12. The detection control device 11 can also control the array detector 12, for example, by outputting signals or commands to the array detector 12 to change the circuit parameters of the detection element. For example, it can adjust one or more of the following circuit parameters in the circuit shown in Figure 2: the voltage Vop at the first voltage input terminal, the voltage Vex at the second voltage input terminal, the resistance value Rq of the quenching resistor, or the threshold voltage Vth of the inverter.

[0081] In some solutions, the voltage adjustment of the first and second voltage input terminals can be achieved through an external circuit control module. For example, the circuit control module can adjust the power supply voltage, thereby adjusting the voltage input to the array detector, making the voltages of the first and second voltage input terminals variable. The resistance value of the quenching resistor and the threshold voltage of the inverter can be adjusted by changing the internal configuration of the chip. Specifically, the quenching resistor, inverter, etc., are electronic components already fixed in the circuit. If their parameters need to be adjusted, the array detector chip needs to be configured to change the parameters of the electronic components in the circuit connected to the detection element.

[0082] For example, the detection control device 11 may include one or more of the following modules with computing and control capabilities: application-specific integrated circuit (ASIC), programmable logic device (PLD), central processing unit (CPU), digital signal processor (DSP), microprocessor unit (MPU), and microcontroller unit (MCU). Among these, the PLD may be a field-programmable gate array (FPGA). In some embodiments, the detection control device 11 may include multiple parts, such as signal processing circuits and control circuits. These multiple parts may be integrated together or set independently; this application does not impose strict limitations on this. In other embodiments, the detection control device 11 may include multiple modules with computing and control capabilities. These modules may be integrated together and implemented as a system-on-a-chip (SOC). For example, the detection control device 11 may be an SOC including a CPU and an MCU.

[0083] In some possible implementations, referring to FIG. 1, the detection device 10 further includes a transmitting module 13. The transmitting module 13 is used to emit a detection beam. Exemplarily, the transmitting module 13 may include one or more of the following lasers: vertical cavity surface emitting laser (VCSEL), photonic crystal surface emitting semiconductor laser (PCSEL), edge emitting laser (EEL), laser diode (LD), distributed feedback laser diode (DFB-LD), grating coupled sampling reflection laser diode (GCSR-LD), or micro opto-electro-mechanical system laser diode (MOEMS-LD), etc. Optionally, the detection control device 11 may also be connected to the transmitting module 13, for example, it may output a control signal to the transmitting module 13 to control the transmitting module 13 to emit the beam.

[0084] An exemplary detection process is as follows: the transmitting module 13 emits a detection beam into the object space. The detection beam is reflected by the target in the object space to form a return beam. The spot of the return beam falls onto the array detector 12 and is received by the detection element 121 of the array detector 12 to obtain measurement data. Among the measurement data output by the array detector 12, some or all of the measurement data can be used to obtain relevant information about the target in the object space, such as one or more of the target's distance, position, angle, velocity, reflectivity, reflection intensity, color, or material.

[0085] Optionally, the detection device 10 may also include a scanning module 14, which is movable to scan the detection beam into the object space. Optionally, the return beam also passes through the scanning module 14. Exemplarily, the scanning module 14 may include, but is not limited to, one or more of a rotating mirror, a tilting mirror, or a galvanometer.

[0086] It should be understood that the architecture of the detection device shown in Figure 1 is only an example. In a specific implementation, the detection device 10 may include more or fewer modules. For example, the detection device 10 may not include a scanning module. Furthermore, the detection device 10 may also include optical elements, such as lenses, shaping modules, or collimation modules, which are not illustrated here.

[0087] As described in the background section, the performance of the detection elements in an array detector is often affected by factors such as changes in ambient temperature and light intensity, resulting in inconsistent dead times of the array detection elements under different PVT conditions, which affects the performance stability of the detection device.

[0088] In view of this, this application provides a detection method, a detection control device, a chip, a lidar, and a terminal, which can improve the stability of the dead time of the detection element under different PVT conditions and ensure the stable performance of the detection device.

[0089] Please refer to Figure 3, which is a flowchart illustrating a detection method provided in an embodiment of this application. This method can be applied to the aforementioned detection device, such as the detection device 10 shown in Figure 1, or executed by the detection control device 11 in the detection device 10 shown in Figure 1. For ease of description, the following description uses the detection control device as the executing entity. In specific implementations, the detection control device can be replaced with other devices, modules, or equipment, such as a SOC, CPU, or main control module.

[0090] The detection method shown in Figure 3 may include steps S301 to S302. It should be understood that, for ease of description, the order of S301 to S302 is used, and it is not intended to limit the execution to this specific order. This application embodiment does not limit the order of execution, the execution time, or the number of executions of one or more of the above steps. S301 to S302 are as follows:

[0091] Step S301: Obtain the first measurement data of the first test pixel in the array detector.

[0092] The array detector comprises multiple pixels, each pixel including at least one detection element. For example, referring to Figures 4 and 5, in the array detector, one pixel may include nine detection elements arranged in a 3x3 configuration. In this case, the data output by the nine detection elements within one pixel is output in a single-pixel mode. For example, the array detector can be a SPAD array detector, a SiPM array detector, etc. For a description of array detectors, please refer to the relevant content regarding the aforementioned array detector 12.

[0093] The first test pixel belongs to multiple pixels. It should be understood that the number of pixels in the first test pixel may be one or more. The following describes three possible scenarios for the pixels in the first test pixel:

[0094] Case 1: The first test pixel includes dark pixels, see Figure 6(a). Measurement data is collected for dark pixels using dark counting. In dark counting, the probability of avalanche is relatively low for the detector element in the pixel, and the probability of multiple detector elements in a pixel triggering avalanche is even lower, so that the measurement data collected by the test pixel can more accurately reflect the dead time of a single detector element.

[0095] Case 2: The first test pixel includes pixels with a window aperture smaller than the length of the photosensitive surface of the pixel. The window aperture is used to control the amount of light entering the test pixel. See Figures 6(b), (c), and (d). An aperture is placed above the photosensitive surface of the test pixel to control the amount of light entering the pixel. The area of ​​the aperture is smaller than the area of ​​the photosensitive surface of the pixel. The smaller the window aperture, the less light enters the pixel, and the lower the probability of avalanche triggering by the detector element in the pixel. It should be noted that the illustration in Figure 6 is only an example; the aperture can be placed above the photosensitive surface of the detector element in the pixel.

[0096] Case 3: The first test pixel includes ordinary normal pixels, as shown in Figure 6(e). Normal pixels do not operate in dark counting mode, and no aperture is set on the detection element.

[0097] It should be understood that the aforementioned scenarios may be combined. For example, when the number of pixels in the first test pixel is multiple, the first test pixel may include dark pixels and normal pixels, or it may include dark pixels and pixels with a window aperture smaller than the length of the photosensitive surface of the pixel.

[0098] The above describes the specific implementation of the pixel. Below are some possible designs for the position of the first test pixel on the array detector:

[0099] Design 1: The array detector comprises multiple pixels, including main pixels and test pixels, located in different regions of the array detector. As shown in Figure 4, taking the test pixel as the first test pixel as an example, the main pixels are located in the main pixel region, while the first test pixel is located in the test pixel region. For example, the first test pixel may be located in test pixel region #1, or in test pixel region #2, or partially in test pixel region #1 and partially in test pixel region #2. The main pixels are used for target detection; for example, the measurement data collected by the main pixels is used to obtain relevant information about targets in the object space. The test pixels, however, are not used for detection; for example, the measurement data collected by the test pixels is used to adjust the circuit parameters of the detection unit of the array detector. Optionally, there may be unused (or inactive) pixels on the array detector (pixels on the left and right sides of the main pixel region as shown in Figure 4). These pixels are currently neither main pixels nor test pixels. Of course, these unused pixels may be activated as main pixels and / or test pixels in subsequent detection processes.

[0100] In Design 2, the first test pixel is also used for target detection. That is, the measurement data collected by the first test pixel is also used to obtain relevant information about the target in the object space. It should be understood that in Design 2, the first test pixel is a normal pixel that is functioning normally, i.e., excluding dark pixels and / or pixels whose window aperture is smaller than the length of the photosensitive surface of the pixel.

[0101] Design 3: The first test pixel is located in a weak-light region or a dark region on the array detector, referred to as the first region for ease of description. For example, the light energy density received by the first region is less than a preset value. Further, for example, the light energy density received by the first region is less than the light energy density received by a second region in the array detector, which is another region that does not overlap with the first region. Referring to Figure 5, when the array detector receives the echo, the area where the echo spot (the pure black filled area shown in Figure 5) is located can be considered a strong-light region on the array detector. The strong-light region has a high light energy density; therefore, for pixels in the strong-light region, multiple detection units may trigger avalanches consecutively, resulting in a high dead-time count. In this case, the dead-time of a single detection unit cannot be accurately determined, so pixels in the strong-light region are not suitable for measuring dead-time values. Conversely, the weak-light region, as shown in Figure 5, where the echo spot does not fall, has a low light energy density and a small dead-time count, making it suitable for measuring dead-time. Therefore, by setting the test pixels in the low-light or no-light areas of the array detector, the measurement data collected by the test pixels can more accurately reflect the dead time of the detection unit, improving the accuracy of the dead time measurement value, and thus improving the accuracy of dead time adjustment.

[0102] The above designs can be combined without mutual exclusion. For example, combining Design 1 and Design 3, the main pixel can be placed in the central region of the array detector, which is prone to receiving echo spots and is a strong light area. The test pixel area is placed in the edge region of the array detector, which is less prone to receiving echo spots and is a weak light area. Alternatively, combining Design 2 and Design 3, after acquiring measurement data, the multiple pixels of the array detector can use the dead time count value of each pixel to select the pixel with the lower dead time count value (i.e., the pixel in the weak light area) as the test pixel. In practice, there may be other implementations combining multiple designs, which will not be described in detail here.

[0103] The measurement data of the first test pixel, i.e., the first measurement data, is used to indicate the dead time information of the first test pixel. For example, the measurement data includes a time interval of multiple dead times, or includes the number of dead time triggers and the total time length. Please refer to Figure 7, which is a schematic diagram of the dead time of a test pixel provided in an embodiment of this application. The test pixel triggers 7 dead times during the detection process, denoted as DT1 to DT7.

[0104] As one possible implementation, the measurement data of the first test pixel may include information about multiple dead time windows of the first test pixel. For example, the measurement data of the first test pixel may include the start time and end time of each dead time, i.e., the start time of DT1, the end time of DT1, the start time of DT2, the end time of DT2, and so on. Alternatively, the measurement data of the first test pixel may include the start time and duration of each dead time, i.e., the start time of DT1 and the duration of DT1, the start time of DT2 and the duration of DT2, and so on. The average length of the dead time can be calculated using the information of the dead time time windows, and the number of dead time triggers can also be indicated.

[0105] As another possible implementation, the measurement data of the first test pixel may include the number of triggers and the total duration of multiple dead time intervals for the first test pixel. Taking Figure 7 as an example, the number of dead time triggers is 7, and the total duration is the sum of the durations of each dead time interval from DT1 to DT7. The average length of the dead time interval of the test pixel can be calculated by using the number of dead time triggers and the total duration.

[0106] Optionally, the measurement data of the first test pixel may also include the photon count value of the dead time of the first test pixel, or the maximum value of the photon count value of the dead time of the first test pixel. This photon count value is related to the number of detectors within the pixel that trigger the dead time. As shown in Figure 7, the photon count values ​​of the dead times of DT1 and DT7 are both 1; in this case, the maximum value of the photon count value of the dead time is 1. In some cases, multiple detectors within a pixel may trigger avalanche in succession; in this case, the photon count value of the pixel's dead time may be greater than 1. As shown in Figure 8, the photon count value of dead time t1 is 2, and the photon count value of dead time t3 is 3; in this case, the maximum value of the photon count value of the dead time is 1.

[0107] In some schemes, to ensure the accuracy of dead time adjustment, the measurement data of the first test pixel is also tested for validity before use.

[0108] As one possible implementation, the first measurement data is used to indicate the photon count for each dead time of the first test pixel and the number of triggers during the dead time of the first test pixel. It should be understood that the number of triggers during the dead time is the number of triggers generated within a certain acquisition period, such as within a first duration. An exemplary validity check can be performed whereby the first measurement data is valid only if the following two conditions are met; otherwise, the first measurement data is invalid: Condition 1, the maximum value of the photon count during the dead time of the first test pixel is lower than a preset counting threshold; Condition 2, the number of triggers during the dead time of the first test pixel reaches a statistical threshold. The counting threshold and the statistical threshold can be pre-designed, pre-defined, or configured by the developer. For example, the counting threshold can be set to 2, 3, 4, etc. Similarly, the statistical threshold can be set to natural numbers such as 100, 1000, etc. By limiting the photon count value and the statistical threshold, the accuracy of the dead time measurement can be improved, thereby improving the accuracy of dead time adjustment.

[0109] In this implementation, the data can be used after the first measurement is detected as valid. When step S302 is executed, the maximum value of the photon count of the dead time of the first test pixel is lower than a preset counting threshold, and the trigger count of the dead time of the first test pixel reaches a statistical threshold.

[0110] It should be noted that the numerical range settings here are merely examples. In actual implementation, the specific condition triggered when the data equals the boundary of the numerical range can be set according to actual needs. For example, condition 1 mentioned above can also be replaced with: the maximum value of the photon count in the dead time of the first test pixel is lower than or equal to a preset counting threshold. Similarly, condition 2 mentioned above can also be replaced with: the trigger count in the dead time of the first test pixel is greater than a statistical threshold.

[0111] Alternatively, in some schemes, the validity test may only test one of the two conditions mentioned above, such as condition 1 or condition 2. Accordingly, in this case, the first measurement data may satisfy one of the conditions.

[0112] In the aforementioned scheme, the first measurement data indicates the photon count for each dead time of the first test pixel. As an alternative, the first measurement data can be used to indicate the maximum photon count value for each dead time of the first test pixel, without indicating the photon count value for each dead time. In this case, by comparing the maximum value with a counting threshold, it can be determined whether the first measurement data satisfies the aforementioned condition 1.

[0113] In some possible implementations, the acquired measurement data may be detected as invalid during validity testing. When the current measurement data is invalid, the pixel binning method can be adjusted through feedback, and / or pixels with different aperture sizes can be selected to ensure the validity of the acquired measurement data. For example, the detection control device can acquire third measurement data from a third test pixel and detect the validity of the third measurement data. Taking the dead time shown in Figure 8 as an example, if the preset counting threshold is 2, the maximum value of the photon count in the dead time shown in Figure 8 exceeds the counting threshold, and the measurement data corresponding to Figure 8 is invalid. Further, in the case of invalid third measurement data, the detection control device can acquire measurement data from a fourth test pixel, where the fourth test pixel has a different aperture than the third test pixel, and / or the fourth test pixel has a different binning method than the third test pixel. For example, if the maximum value of the photon count in the third measurement data exceeds the counting threshold, it indicates that the light transmission of the third test pixel is large. In this case, measurement data from a pixel with a smaller aperture or a lower binning value can be acquired. For example, if the number of dead time triggers in the third measurement data does not reach the statistical threshold, it indicates that the number of avalanche triggers is relatively small. In this case, measurement data from pixels with larger apertures or higher binning values ​​can be obtained.

[0114] Among them, the third test pixel belongs to multiple pixels, and the fourth test pixel also belongs to multiple test pixels.

[0115] In some schemes, the third and fourth test pixels can be located in different regions, corresponding to two different sets of detector elements. In this scheme, the aperture of the fourth test pixel is different from that of the third test pixel, or the binning methods of the third and fourth test pixels are different. For example, the binning method of the third test pixel is to add the outputs of 4 detector elements in a 2*2 pattern, while the binning method of the fourth test pixel is to add the outputs of 9 detector elements in a 3*3 pattern.

[0116] In other schemes, the third and fourth test pixels can be located in the same area, or their areas on the array detector can overlap; for example, the third and fourth test pixels may correspond to some of the same detection elements. In this scheme, the binning methods of the third and fourth test pixels are different.

[0117] Step S302: Adjust the circuit parameters of the detection element in the first target pixel based on the first measurement data and the first dead time target value.

[0118] The target value for the first dead time can be predefined or configured by the developers. For example, it can be written into the memory by the developers at the factory. In some solutions, developers can conduct simulation tests on the array detector in a laboratory environment and use the dead time value that achieves optimal detection performance as the target dead time value.

[0119] The first target pixel belongs to the plurality of pixels included in the array detector. The first target pixel includes at least the first test pixel. Optionally, in addition to the first pixel, the first target pixel also includes other pixels. For example, referring to Figure 4, the first test pixel is a pixel in test pixel area #1 and / or test pixel area #2, while the first target pixel, in addition to the first test pixel, also includes pixels in the main pixel area. Further exemplarily, referring to Figure 5, the first test pixel is a pixel in a low-light area, while the first target pixel includes pixels in both low-light and high-light areas.

[0120] The circuit of the detection element is used to drive the detection element to work, and the circuit parameters are the parameters in the circuit of the detection element. As shown in the relevant description in Figure 2, the circuit parameters of the detection element may include one or more of the following: the voltage Vop at the first voltage input terminal, the voltage Vex at the second voltage input terminal, the resistance value Rq of the quenching resistor, or the threshold voltage Vth of the inverter.

[0121] In this application, the measurement data reflects the dead time of the test pixel in the array detector under current environmental conditions. Based on this measurement data and a first dead time target value, the circuit parameters in the first target pixel can be adjusted. Adjusting the circuit parameters can change the performance of the detection elements in the array detector, allowing the dead time of the first target pixel to change towards a value closer to the first dead time target value.

[0122] As one possible implementation, the detection control device can determine the measured value of the dead time based on the first measurement data. For example, it can obtain the average value of the dead time of the first test pixel based on the first measurement data, which is the measured value of the dead time. Based on the measured value of the dead time and the first dead time target value, the circuit parameters can be adjusted to achieve dynamic correction of the dead time of the array detector. For example, taking the voltage Vop at the first voltage input terminal as the circuit parameter, the detection control device can increase or decrease the voltage Vop at the first voltage input terminal of each detection element in the first target pixel according to the measured value of the dead time and the first dead time target value, so that the dead time value of the first target pixel changes in a direction closer to the first dead time target value, thereby improving the stability of the dead time of the array detector under different PVT conditions.

[0123] In one possible implementation, the detection control device determines the measured value of the dead time of the first test pixel based on the first measurement data, determines a first compensation amount based on the measured value of the dead time of the first test pixel and a target value of the first dead time, and adjusts the circuit parameters of the detection element in the first target pixel based on the first compensation amount. The compensation amount reflects the difference between the measured value and the target value of the dead time. Adjusting based on the compensation amount can compensate and correct the dead time of the detection element towards the target value.

[0124] In some solutions, there may be multiple ways to perform adjustment operations when adjusting circuit parameters. For example, the detection control device can adjust the voltage input to the array detector via a control module, thereby adjusting the voltage Vop at the first voltage input terminal and / or the voltage Vex at the second voltage input terminal. As another example, the detection control device can adjust by outputting control signals or commands. For instance, the detection control device can output control signals to the array detector chip to instruct the array detector to adjust the circuit parameters of the detection element in the first target pixel (i.e., triggering adjustments to the internal configuration of the array detector chip), such as adjusting the resistance value Rq of the quench resistor and / or the threshold voltage Vth of the inverter.

[0125] Please refer to Figure 9, which is a schematic diagram of the operation process of a detection method provided in an embodiment of this application. Taking the main pixel and test pixel as separate configurations as an example, the main pixel and test pixel can collect measurement data separately. The collected data is sampled, read out, and then input to the DSP module for processing. The measurement data processed by the DSP module can be output to the host, where the host is used to exemplarily represent the processing module used for feedback adjustment. The host can determine the compensation amount based on the measurement data and the target value of the dead time. During adjustment, the voltage input from the power supply to the array detector is adjusted by the control module, thereby adjusting the circuit parameters (such as Vop and Vex) of the front-end circuits of the main pixel and test pixel. At this time, the host (or combined with the control module) can be regarded as a detection control device. Furthermore, the host can be integrated into the array detector, for example, the host can be an array detector chip.

[0126] Please refer to Figure 10, which is a schematic diagram of the operation process of another detection method provided in this application embodiment, taking the main pixel and test pixel as separate settings as an example. The information flow process in the early stage can be referred to the relevant description in Figure 9. In Figure 10, the measurement data processed by the DSP module can be output to the Host. The Host can determine the compensation amount based on the measurement data and the target value of the dead time. When adjusting the circuit parameters, the Host instructs the chip of the array detector to adjust the chip configuration by outputting instructions (or signals) to the chip, thereby adjusting the parameters of the front-end circuit of the detection element (e.g., adjusting Rq and Vth). At this time, the Host (or combined with the array detector chip) can be regarded as a detection control device. Optionally, the Host and the array detector can be set separately, but there can be a communication connection between them. The communication connection here includes wired and wireless connections, so that the Host can output instructions (or signals) to the array detector. Alternatively, the Host can be integrated into the array detector, for example, the Host can be the array detector chip.

[0127] To facilitate understanding of the adjustment process, two methods for controlling the dead time of pixels are introduced below:

[0128] Method 1: Based on a PID algorithm, the dead time of the pixel is controlled in a closed-loop, dynamic manner. Referring to Figure 11, the detection control device determines the measured value of the dead time of the first test pixel (i.e., the dead time measurement value shown in Figure 11) based on the first measurement data. Then, based on the measured value of the dead time of the first test pixel and the first dead time target value (i.e., the target value shown in Figure 11), a first compensation amount is determined using the proportion-integral-differential (PID) method. The parameters of the front-end circuit of the detection element in the first target pixel are adjusted according to the first compensation amount. Furthermore, the adjustment process may be performed multiple times. For example, after adjustment, the detection control device can acquire the measurement data of the first test pixel again (i.e., the monitoring pixel) and perform subsequent readjustments. That is, the method shown in Figure 3 can be executed multiple times.

[0129] Method 2 combines the binary search method and the pre-bias method to dynamically control the dead time of the pixel in a closed loop. Referring to Figure 12, the detection control device determines the adjustment granularity based on the difference between the measured dead time of the first test pixel and the target dead time value. It then determines the first compensation amount based on the adjustment granularity and the bias value, and adjusts the parameters of the front-end circuit of the detection element in the first target pixel according to the first compensation amount. Here, the pre-bias is a predefined or pre-configured bias value. The granularity reflects the magnitude of the adjustment amount; for example, it may include both coarse and fine adjustment granularities. When the difference is large, the adjustment granularity is coarse; when the difference is small, the adjustment granularity is fine. Based on the adjustment granularity and the pre-set bias value, the compensation amount is output to adjust the value of the controlled object to approach the target value.

[0130] Optionally, the difference and / or compensation amount can have a sign, which is used to determine the direction of adjustment. As shown in Figure 12, the direction of adjustment is determined by judging the positive or negative sign of the difference between the measured dead time value and the target dead time value. The numerical value of the difference can be used to determine the adjustment granularity, and further combined with the pre-bias to determine the compensation amount. During adjustment, the parameters of the front-end circuit of the detection element in the first target pixel are adjusted based on the adjustment direction and the first compensation amount.

[0131] Optionally, the adjustment granularity can be determined using a dichotomy method. For example, if the difference exceeds half of the target value of the dead time, the adjustment granularity is coarse. If the deviation does not exceed half of the target value of the dead time, the adjustment granularity is fine. Of course, different adjustment granularities can be designed for various cases where the difference exceeds one-half, one-quarter, one-eighth, etc.

[0132] Of course, the two control processes mentioned above are just examples. In the actual implementation process, other methods can be designed to adjust the circuit parameters.

[0133] In some solutions, to adapt to the different adjustment levels required by the detection device under varying operating environments, multiple target values ​​can be designed within the device. Different environmental conditions correspond to different dead-time target values. For example, different target values ​​can be used under high-temperature and low-temperature conditions. Similarly, different target values ​​can be used under strong light and dark conditions. Thus, based on multiple dead-time target values, various compensation levels can be calculated for selection during adjustment, ensuring that dead-time control is adapted to the current operating environment and improving the detection performance of the device.

[0134] As one possible implementation, the detection control device can also acquire second measurement data from the second test pixel and determine the second dead time compensation amount based on the second measurement data and the second dead time target value. The second test pixel also comprises multiple pixels, and the second measurement data is used to indicate the dead time information of the second test pixel. The first dead time target value corresponds to the dead time target value under the first environmental condition, and the second dead time target value corresponds to the dead time target value under the second environmental condition. The dead time target values ​​corresponding to different environmental conditions can be predefined. For example, developers can conduct simulation tests on the array detector in a laboratory environment to determine the dead time value that achieves optimal detection performance under different environmental conditions, which is then used as the dead time target value under that environmental condition.

[0135] Furthermore, the detection control device can determine, based on environmental information, that the first dead-time compensation amount (either a first dead-time compensation amount or a second dead-time compensation amount) is used to adjust the parameters of the front-end circuit of the detection element in the first target pixel. Since the first dead-time target value and the second dead-time target value correspond to different environmental conditions, when determining the compensation amount used to adjust the front-end circuit, the current environmental conditions can be determined based on the environmental information, thereby selecting the corresponding compensation amount for adjustment. In the above implementation, the first compensation amount can be determined as the compensation amount used for adjustment based on environmental information; that is, the current environment is determined to belong to the first environmental condition based on the environmental information.

[0136] In one possible design, the first test pixel and the second test pixel are located in different areas of the array detector. Referring to Figure 13, the array detector can be equipped with two sets of test pixels, test pixel 1 and test pixel 2. The data collected by the two sets of test pixels can be combined with two target values ​​(i.e., target value 1 and target value 2) to obtain two compensation levels. When adjusting the dead time of the first target pixel, taking the main pixel as an example, compensation level 1 or compensation level 2 can be selected as the compensation level for adjusting the main pixel, thereby adjusting the circuit parameters. Of course, the two sets of test pixels here are only examples; in a specific implementation, more test pixels can be set to provide more selectable compensation levels.

[0137] In another possible design, the first test pixel and the second test pixel are located in the same area of ​​the array detector. Further, the first and second measurement data can be the same set of measurement data, or two sets of measurement data collected at different time periods. Referring to Figure 14, a test pixel can be set on the array detector. The two sets of measurement data collected by this test pixel at different times can be processed to obtain two dead-time measurement values. These two dead-time measurement values ​​can be calculated with two dead-time target values ​​to obtain two compensation levels. When adjusting the dead-time of the first target pixel, taking the main pixel as an example, compensation level 1 or compensation level 2 can be selected as the compensation level for adjusting the main pixel, thus adjusting the circuit parameters. Of course, the two compensation levels here are only examples; in specific implementations, more dead-time target values ​​can be set to provide more selectable compensation levels.

[0138] In some schemes, the detection device may include multiple sets of target pixels. These multiple sets of target pixels can be controlled using measurement data acquired from the same or different test pixels. For example, the detection control device may adjust the circuit parameters of the detection element of a second target pixel located in a different region on the array detector, based on first measurement data and a first dead-time target value.

[0139] It should be understood that this scheme can be combined with the aforementioned various possible implementations. For example, the detection control device can select one compensation amount from a first compensation amount and a second compensation amount to adjust the circuit parameters of the detection element of the second target pixel. Two possible designs are described below:

[0140] In one possible design, as shown in Figure 15, the array detector includes multiple sets of main pixels and multiple sets of test pixels. The main pixel sets include, for example, main pixel 1, main pixel 2, etc., and the test pixel sets include, for example, test pixel 1, test pixel 2, etc. The data collected by the two sets of test pixels can be combined with two target values ​​(target value 1 and target value 2) to obtain two compensation levels. When adjusting the dead time of main pixel 1 and main pixel 2, compensation level 1 or compensation level 2 can be independently selected as the compensation level for adjusting the main pixels, thus adjusting the circuit parameters of the detection elements of main pixels 1 and 2. For example, when adjusting main pixel 1, one of compensation level 1 and compensation level 2 can be selected for adjustment; similarly, when adjusting main pixel 2, one of compensation level 1 and compensation level 2 can also be selected for adjustment. Of course, the two sets of test pixels here are only an example; in a specific implementation, more test pixels can be set to provide more selectable compensation levels.

[0141] In another possible design, as shown in Figure 16, the array detector includes multiple sets of main pixels and test pixels. The main pixels include, for example, main pixel 1, main pixel 2, etc. The data collected by the test pixels is processed to obtain a dead time measurement. This dead time measurement can be calculated with multiple dead time target values ​​to obtain multiple compensation levels. When adjusting the dead time of main pixel 1 and main pixel 2, compensation level 1 or compensation level 2 can be independently selected as the compensation level for adjusting the main pixels, thus adjusting the circuit parameters of the detection elements of main pixels 1 and 2. For example, when adjusting main pixel 1, one of compensation level 1 and compensation level 2 can be selected for adjustment; similarly, when adjusting main pixel 2, one of compensation level 1 and compensation level 2 can also be selected for adjustment. Of course, the two compensation levels here are only examples; in a specific implementation, more dead time target values ​​can be set to provide more selectable compensation levels.

[0142] In the embodiment shown in Figure 3, the detection control device can acquire measurement data of the test pixel and adjust the circuit parameters in the first target pixel based on the measurement data and the first dead time target value. The circuit parameter adjustment can change the performance of the detection elements in the array detector, so that the dead time of the first target pixel can change in a direction closer to the first dead time target value.

[0143] Thus, based on the first test data, the current measured value of the dead time can be determined. By combining the measured value of the dead time with the first target value of the dead time, the circuit parameters can be adjusted to achieve dynamic correction of the dead time of the array detector. Under different PVT conditions, the closed-loop control scheme of detection, feedback, and correction provided in this application can improve the stability of the dead time of the detection element and ensure the stable performance of the detection device.

[0144] The methods of the embodiments of this application have been described in detail above, and some possible implementations have been given. Below, some apparatuses for implementing the aforementioned methods are described. It should be understood that the division of units in the apparatuses provided in the embodiments of this application is only a logical functional division; in actual implementation, they can be fully or partially integrated onto a single physical entity, or they can be physically separated.

[0145] Furthermore, the units in the device can be implemented in the form of processor calling software. For example, the device includes a processor connected to a memory that stores instructions. The processor calls the instructions stored in the memory to implement any of the above methods or to implement the functions of each unit of the device. The processor is, for example, a general-purpose processor, such as a CPU or MPU, and the memory is either internal or external to the device.

[0146] Alternatively, the units in the device can be implemented as hardware circuits. The functionality of some or all units can be achieved through the design of these hardware circuits, which can be understood as one or more processors. For example, in one implementation, the hardware circuit is an ASIC, and the functionality of some or all of the above units is achieved through the design of the logical relationships between the components within the circuit. In another implementation, the hardware circuit can be implemented using a PLD (Programmable Logic Controller). Taking an FPGA as an example, it can include a large number of logic gates, and the connection relationships between these logic gates are configured through configuration files, thereby achieving the functionality of some or all of the above units. All units of the above device can be implemented entirely through processor-invoked software, entirely through hardware circuits, or partially through processor-invoked software with the remaining parts implemented through hardware circuits.

[0147] In this application embodiment, a processor is a circuit with signal processing capabilities. In one implementation, the processor can be a circuit with instruction read and execute capabilities, such as a CPU or a DSP. In another implementation, the processor can implement certain functions through the logical relationships of hardware circuits. These logical relationships are fixed or reconfigurable; for example, the processor is a hardware circuit implemented as an ASIC or PLD, such as an FPGA. In a reconfigurable hardware circuit, the process of the processor loading a configuration document and configuring the hardware circuit can be understood as the process of the processor loading instructions to implement the functions of some or all of the above units. Therefore, each unit in the device can be one or more processors (or processing circuits) configured to implement the above methods, such as: CPU, GPU, microprocessor, DSP, ASIC, FPGA, or a combination of at least two of these processor types.

[0148] Furthermore, the units in the above devices can be integrated in whole or in part, or they can be implemented independently. In one implementation, these units are integrated together and implemented in the form of a System-on-Chip (SoC). The SoC may include at least one processor for implementing any of the above methods or implementing the functions of the units in the device. The at least one processor may be of different types, such as CPU and FPGA.

[0149] Several possible devices are listed below.

[0150] Please refer to Figure 17, which is a schematic diagram of a detection control device provided in an embodiment of this application, namely, detection control device 170. Optionally, the detection control device 170 can be an independent device, such as the detection control device 11 shown in Figure 1. Alternatively, the detection control device 170 can also be a component in an independent device (such as a node), such as a chip or integrated circuit. The detection control device 170 is used to implement the aforementioned detection method.

[0151] As shown in Figure 17, the detection control device 170 includes an acquisition unit 1701 and a processing unit 1702. The acquisition unit 1701 performs one or more operations such as acquisition, reception, listening, and transmission, and further includes other operations for implementing the detection method. The processing unit 1702 performs one or more operations such as processing, calculation, determination, generation, and updating, and further includes other operations for implementing the detection method.

[0152] For related descriptions, please refer to the description of the embodiment shown in Figure 3, which will not be described in detail here.

[0153] Please refer to Figure 18, which is a schematic diagram of another detection control device provided in an embodiment of this application. The detection control device 180 can be a standalone device or a component included in a standalone device, such as a chip, software module, or integrated circuit. The detection control device 180 may include at least one processor 1801 and a communication interface 1802. Optionally, it may also include at least one memory 1803. Further optionally, it may also include a connection line 1804, wherein the processor 1801, the communication interface 1802, and / or the memory 1803 are connected via the connection line 1804, and / or communicate with each other via the connection line 1804 to transmit control signals and / or data signals.

[0154] in:

[0155] Processor 1801 is a module that performs arithmetic and / or logical operations, and may specifically include one or more of the following modules: filter, modem, power amplifier, low noise amplifier (LNA), baseband processor, radio frequency processor, radio frequency circuit, central processing unit (CPU), application processor (AP), microcontroller unit (MCU), electronic control unit (ECU), graphics processing unit (GPU), microprocessor unit (MPU), application specific integrated circuit (ASIC), image signal processor (ISP), digital signal processor (DSP), field programmable gate array (FPGA), complex programmable logic device (CPLD), or coprocessor, etc.

[0156] The communication interface 1802 can be used to provide information input or output to the at least one processor, or to receive signals sent from the outside and / or send signals to the outside.

[0157] For example, communication interface 1802 may include interface circuitry. For example, communication interface 1802 may include a wired link interface such as a bus, or a wireless link interface (Wi-Fi, Bluetooth, general wireless transmission, vehicular short-range communication technology, and other short-range wireless communication technologies, etc.). As a possible design, if the detection control device 180 is a standalone device, communication interface 1802 may include a receiver and a transmitter. The receiver and transmitter may be the same component or different components. When the receiver and transmitter are the same component, this component may be referred to as a transceiver. As yet another possible design, if the detection control device 180 is a chip or circuit, communication interface 1802 may include an input interface and an output interface, which may be the same interface or different interfaces.

[0158] Alternatively, the functionality of the communication interface 1802 can be implemented via transceiver circuitry or a dedicated transceiver chip.

[0159] The memory 1803 provides storage space, in which data such as the operating system and computer programs can be stored. The memory 1803 can be one or a combination of several of the following: random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or compact disc read-only memory (CD-ROM).

[0160] The functions and actions of each module or unit in the detection and control device 180 listed above are merely illustrative examples.

[0161] Each functional unit in the detection control device 180 can be used to implement the aforementioned detection method, such as the detection method shown in FIG13. Optionally, if the detection control device 180 includes at least one memory 1803, and the processor 1801 implements the aforementioned detection method by calling a computer program, the computer program can be stored in the memory 1803.

[0162] This application also provides a lidar, which includes the aforementioned detection device (e.g., detection device 10). The detection device includes a detection control device for implementing the aforementioned detection method, such as the detection method shown in FIG3.

[0163] This application also provides a terminal that includes the aforementioned detection device (e.g., detection device 10), or the aforementioned detection control device 170, or the aforementioned detection control device 180, or the aforementioned lidar.

[0164] In this application, the terms "exemplarily" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplarily" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the terms "exemplarily" or "for example" is intended to present the relevant concepts in a specific manner.

[0165] In this application, "at least one" in the embodiments refers to one or more items, and "more than one" refers to two or more items. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can represent: a, b, c, (a and b), (a and c), (b and c), or (a and b and c), where a, b, and c can be single or multiple. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0166] Furthermore, unless otherwise stated, the use of ordinal numbers such as "first" and "second" in the embodiments of this application is for distinguishing multiple objects and is not for limiting the order, sequence, priority or importance of multiple objects.

Claims

1. A method of detecting, characterized by, The method comprises: obtaining first measurement data of a first test pixel in an array detector, the first measurement data being used to indicate dead time information of the first test pixel, the array detector comprising a plurality of pixels, each pixel in the plurality of pixels comprising at least one detection element, the first test pixel belonging to the plurality of pixels; based on the first measurement data and a first dead time target value, adjusting a circuit parameter of a detection element in a first target pixel to adjust a dead time of the first target pixel, the first target pixel belonging to the plurality of pixels and the first target pixel comprising at least the first test pixel.

2. The method of claim 1, wherein, The circuit connected to each detection element comprises a first voltage input end, a second voltage input end, a quenching resistor and an inverter, the first voltage input end and the second voltage input end are used to power the corresponding detection element, the quenching resistor is used to divide the voltage for the corresponding detection element, one end of the inverter is connected to the corresponding detection element, and the other end of the inverter is connected to the readout circuit of the corresponding detection element; the circuit parameter comprises one or more of the following: a voltage value of the first voltage input end, a voltage value of the second voltage input end, a resistance value of the quenching resistor and a threshold voltage of the inverter.

3. The method according to claim 1 or 2, characterized in that, The first test pixel is in a first region of the array detector, the receiving light energy density of the first region is less than a preset value, or the receiving light energy density of the first region is less than the receiving light energy density of a second region in the array detector.

4. The method according to any one of claims 1 to 3, characterized in that, The first target pixel further comprises a main pixel in the array detector, the main pixel of the array detector being used for target detection, the main pixel and the first test pixel being located in different regions of the array detector.

5. The method according to any one of claims 1 to 3, characterized in that, The first test pixel is also used for target detection.

6. The method of any one of claims 1-4, wherein: the first test pixel comprises a dark pixel, the dark pixel collecting data in a dark counting manner, or, the first test pixel comprises a pixel with an open window aperture smaller than the photosensitive area of the pixel, the open window aperture being used to control the amount of light entering the pixel.

7. The method according to any one of claims 1 to 6, characterized in that, The adjusting of the circuit parameter of the detection element in the first target pixel based on the first measurement data and the first dead time target value comprises: determining a measured value of the dead time of the first test pixel according to the first measurement data; determining a first compensation amount according to the measured value of the dead time of the first test pixel and the first dead time target value; adjusting the circuit parameter of the detection element in the first target pixel according to the first compensation amount.

8. The method of claim 7, wherein, The determination of the first compensation amount according to the measured value of the dead time of the first test pixel and the first dead time target value comprises: determining the first compensation amount by a proportional-integral-derivative (PID) method according to the measured value of the dead time of the first test pixel and the first dead time target value.

9. The method of claim 7, wherein, The determination of the first compensation amount according to the measured value of the dead time of the first test pixel and the first dead time target value comprises: determining an adjustment granularity according to a difference between a measured value of a dead time of the first test pixel and the first dead time target value; determining the first compensation amount according to the adjustment granularity and a bias value, the bias value being predefined.

10. The method according to any one of claims 7-9, characterized in that, The method further comprises: obtaining second measurement data from a second test pixel, the second measurement data being used to indicate dead time information of the second test pixel, the second test pixel belonging to the plurality of pixels; determining a second dead time compensation amount according to the second measurement data and a second dead time target value, the first dead time target value being a dead time target value corresponding to a first environmental condition, the second dead time target value being a dead time target value corresponding to a second environmental condition; determining, according to environmental information, that the first dead time compensation amount among the first dead time compensation amount and the second dead time compensation amount is used to adjust a parameter of a front-end circuit of a detection element in the first target pixel.

11. The method of claim 10, wherein, The first test pixel and the second test pixel are located in different regions of the array detector, Or, the first test pixel and the second test pixel are located in the same region of the array detector, but the collection time of the first measurement data and the second measurement data is different.

12. The method according to any one of claims 1 to 11, characterized in that, The first measurement data is used to indicate a photon count of each dead time of the first test pixel and a trigger number of the dead time of the first test pixel, A maximum value of the photon count of the dead time of the first test pixel is lower than a preset design number threshold value, and / or the trigger number of the dead time of the first test pixel reaches a statistical quantity threshold value.

13. The method of claim 12, wherein, The method further comprises: obtaining third measurement data from a third test pixel, the third test pixel belonging to the plurality of pixels, the third measurement data being used to indicate a photon count of each dead time of the third test pixel and a trigger number of the dead time of the third test pixel; detecting validity of the third measurement data; in a case where the third measurement data is invalid, obtaining measurement data of a fourth test pixel, the fourth test pixel being different from the third test pixel in an aperture and / or the fourth test pixel being different from the third test pixel in a binning mode; the first measurement data is valid when one or more of the following conditions is met, otherwise the third measurement data is invalid: condition 1: a maximum value of the photon count of the dead time of the third test pixel is lower than the preset design number threshold value, condition 2: the trigger number of the dead time of the third test pixel reaches the statistical quantity threshold value.

14. A detection control device, characterized by comprising: The detection device comprises an acquisition unit and a processing unit, and the detection control device is used to implement the method of any one of claims 1-13.

15. A detection control device, characterized by comprising: The detection device comprises a processor and a memory, The memory is used to store computer instructions, The processor is used to call the computer instructions stored in the memory, so that the detection device implements the method of any one of claims 1-14.

16. A chip, characterized by The chip comprises a processor and a communication interface, the communication interface is used for inputting and / or outputting information, and the processor is used for executing computer instructions to realize the method in any one of claims 1-13.

17. A lidar, comprising: The laser radar comprises a transmitting module and an array detector, and further comprises the detection control device in claim 14 or 15 or the chip in claim 16. The array detector comprises a plurality of pixels, each pixel of the plurality of pixels comprises at least one detection element, and each detection element is connected to a corresponding circuit. The transmitting module is used for transmitting a light beam. The array detector is used for receiving a return wave of the light beam.

18. A terminal, characterized by The terminal comprises the detection control device in claim 14 or 15, or comprises the chip in claim 16, or comprises the laser radar in claim 17.

19. The terminal according to claim 18, characterized by The terminal comprises a vehicle, a drone or a robot.

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