Circuit, method and radar for detecting ambient light

Abstract

The application relates to a circuit, a method and a radar for detecting ambient light, the circuit comprising: a light-sensing component for converting a received light signal into a current signal; an electrical signal conditioning circuit coupled with the light-sensing component, for converting the current signal into a voltage signal; a detection processing unit coupled with the electrical signal conditioning circuit, for converting the voltage signal into a digital signal based on a voltage threshold; and a digital processing unit coupled with the detection processing unit, for processing the digital signal to obtain ambient light information. The application can detect ambient light, improve the anti-sunlight noise capability of a laser radar, improve the accuracy of the detection result of the laser radar, and further improve the personal safety and property safety of a user.

Description

[0001] This application is a divisional application. The original application has the application number 202310316097.6 and the filing date is March 16, 2023. The entire contents of the original application are incorporated herein by reference. Technical Field

[0002] This application relates to the field of computer technology, and more particularly to a circuit, method, and radar for detecting ambient light. Background Technology

[0003] With the rapid development of computer technology, information technology, and other related fields, driver assistance and autonomous driving functions are increasingly becoming part of people's daily lives. Taking autonomous driving technology as an example, radar can collect environmental information so that the autonomous driving decision-making system can adopt driving strategies adapted to the environment, such as obstacle avoidance.

[0004] The applicant found that ambient light has a significant impact on the detection results of lidar, and related technologies are not easy to improve the lidar's resistance to sunlight noise at low cost and low power consumption, and it is not easy to improve the accuracy of lidar detection results. Summary of the Invention

[0005] To address or partially address the problems existing in related technologies, this application provides a circuit, method, and radar for detecting ambient light, which can detect ambient light, improve the anti-sunlight noise capability of lidar, improve the accuracy of lidar detection results, and thus enhance the personal and property safety of users.

[0006] The first aspect of this application provides a circuit for detecting ambient light, including a photosensitive element, an electrical signal conditioning circuit, a detection processing unit, and a digital processing unit. The photosensitive element converts a received optical signal into a current signal; the electrical signal conditioning circuit, coupled to the photosensitive element, converts the current signal into a voltage signal; the detection processing unit, coupled to the electrical signal conditioning circuit, converts the voltage signal into a digital signal based on a voltage threshold; and the digital processing unit, coupled to the detection processing unit, processes the digital signal to obtain ambient light information.

[0007] A second aspect of this application provides a radar, including the aforementioned circuit for detecting ambient light and a processor. The circuit for detecting ambient light is used to acquire ambient light information; the processor is coupled to the circuit for detecting ambient light and is used to process the received laser signal based on the ambient light information to reduce interference from ambient light on the laser signal.

[0008] A third aspect of this application provides a method for detecting ambient light, comprising: converting a received light signal into a current signal; converting the current signal into a voltage signal; converting the voltage signal into a digital signal based on a voltage threshold; and processing the digital signal to obtain ambient light information.

[0009] A fourth aspect of this application provides an electronic device, including: a processor; and a memory having executable code stored thereon, which, when executed by the processor, causes the processor to perform the method described above.

[0010] The fifth aspect of this application provides a computer-readable storage medium having executable code stored thereon, which, when executed by a processor of an electronic device, causes the processor to perform the method described above.

[0011] The sixth aspect of this application provides a computer program product including executable code that, when executed, implements the method described above.

[0012] The technical solution provided in this application may include the following beneficial effects: In some embodiments of this application, photosensitive components are used to convert optical signals into current signals, and the current signals are converted into digital signals based on voltage thresholds to reduce interference from ambient light on the laser. This embodiment does not use analog-to-digital converter (ADC) sampling, thus enabling sampling of ambient light, which simplifies circuit design and reduces cost and power consumption.

[0013] Furthermore, in some embodiments of this application, the digital processing unit superimposes digital signals within M time units in a start-time aligned manner to obtain an ambient light digital signal. This can effectively mitigate the impact of ambient light on lasers under conditions such as high illumination and light pollution.

[0014] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0015] The above and other objects, features and advantages of this application will become more apparent from the more detailed description of exemplary embodiments thereof in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments thereof.

[0016] Figure 1 This is a schematic diagram illustrating an application scenario of a circuit, method, and radar for detecting ambient light, as shown in one embodiment of this application. Figure 2 This is a schematic diagram illustrating another application scenario of the circuit, method, and radar for detecting ambient light, as shown in one embodiment of this application; Figure 3 This is a block diagram of a circuit for detecting ambient light according to an embodiment of this application; Figure 4 This is a block diagram of an electrical signal conditioning circuit shown in one embodiment of this application; Figure 5This is a schematic diagram illustrating the principle of electrical signal conditioning according to an embodiment of this application; Figure 6 This is a block diagram of another circuit for detecting ambient light, as shown in one embodiment of this application; Figure 7 This is a schematic diagram illustrating the superposition of digital signals over M time units according to an embodiment of this application; Figure 8 This is a flowchart illustrating the process of detecting ambient light according to an embodiment of this application; Figure 9 This is a schematic diagram illustrating a data filtering method according to an embodiment of this application; Figure 10 This is another schematic diagram illustrating data filtering according to an embodiment of this application; Figure 11 This is a block diagram of another circuit for detecting ambient light, as shown in one embodiment of this application; Figure 12 This is a flowchart illustrating the accumulation of quantities according to an embodiment of this application; Figure 13 This is a flowchart illustrating the accumulation of width values ​​according to an embodiment of this application; Figure 14 This is a schematic diagram illustrating the accumulation of quantities according to an embodiment of this application; Figure 15 This is a schematic diagram illustrating the accumulation of width values ​​according to an embodiment of this application; Figure 16 This is a schematic flowchart illustrating a method for detecting ambient light according to an embodiment of this application; Figure 17 This is a schematic diagram of the radar structure shown in one embodiment of this application; Figure 18 This is a schematic diagram of the structure of an electronic device shown in an embodiment of this application. Detailed Implementation

[0017] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0018] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a” and “the” as used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0019] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0020] To facilitate understanding of this application, some of the concepts involved in this application will be explained first.

[0021] LiDAR: Based on applications, it can be divided into remote sensing, military, and vehicle-mounted applications. Vehicle-mounted radar has a detection range of 200 to 500 meters, and the physical attributes it can identify may only include distance and reflectivity. It can be used in vehicles, robots, and other small machines. Vehicle-mounted radar includes vehicle-mounted lidar, vehicle-mounted millimeter-wave radar, and vehicle-mounted ultrasonic radar.

[0022] Vehicle-mounted LiDAR: Emits light with a wavelength of approximately 900nm (such as a laser beam). When this light encounters an obstacle, it is reflected. The processing unit calculates the distance between the obstacle and the vehicle-mounted LiDAR based on the time difference between the reflected and emitted light. However, the reflected light received by the LiDAR is affected by ambient light. The degree of interference from ambient light differs between strong and weak lighting conditions, requiring processing methods such as compensation to reduce this interference.

[0023] The processing unit of a lidar system can estimate the reflectivity of a target based on the cross-sectional characteristics of the reflected light signal obtained after receiving the reflected light. Reducing ambient light interference helps improve the accuracy of the estimated target reflectivity. Vehicle-mounted lidar systems are characterized by their small size and high degree of integration.

[0024] Artificial intelligence (AI) is a comprehensive technology within computer science. Among its applications, autonomous driving technology is developing particularly rapidly. Autonomous driving technology encompasses high-precision mapping, environmental perception, behavioral decision-making, path planning, and motion control, and has broad application prospects.

[0025] In autonomous driving scenarios, the system architecture suitable for autonomous driving can include mobile devices, networks, and the cloud. Among them, networks include wired networks and wireless networks, etc., which are not limited herein.

[0026] The cloud can include server clusters or distributed systems consisting of multiple physical servers. The cloud can also be cloud servers that provide basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, content delivery network (CDN), and big data and artificial intelligence platforms.

[0027] Mobile devices include, but are not limited to, automobiles, ships, robots, and aircraft. Mobile devices may be equipped with electronic devices such as sensors to obtain information about obstacles in their surrounding environment. These electronic devices may include radar (including lidar), image sensors, etc.

[0028] This application provides a circuit, method, and radar for detecting ambient light. A photoelectric conversion is performed by a photosensitive element, and after conditioning by an electrical signal circuit, a digital signal is output after detection processing. A digital processing unit superimposes the digital signals according to time, number of pulses, or pulse width, and obtains the ambient light result after filtering. By sampling ambient light without using traditional sampling methods, this method simplifies circuit design, reduces cost and power consumption, and ultimately ensures the personal and property safety of users.

[0029] The technical solutions of the embodiments of this application are described in detail below with reference to the accompanying drawings.

[0030] Figure 1 This is a schematic diagram illustrating an application scenario of a circuit, method, and radar for detecting ambient light, as shown in one embodiment of this application.

[0031] Figure 1The hardware configuration of a vehicle 10 supporting assisted driving or autonomous driving functions is shown. For example, at least one LiDAR (Laser Imaging Detection and Ranging) 11 is mounted on the roof and / or sides of the vehicle 10. The detection area of ​​the LiDAR 11 can be fixed, such as a LiDAR 11 being used only to detect a preset area. The detection area of ​​the LiDAR 11 can be adjustable, such as the LiDAR on the vehicle body scanning multiple detection areas by adjusting its posture, or by adjusting the field of view of the LiDAR itself. Specifically, the vehicle 10 can be equipped with five LiDARs 11: one on the top of the vehicle, one on the front of the vehicle, one on the rear of the vehicle, one on the left side of the vehicle, and one on the right side of the vehicle. With multiple LiDARs 11, the outlines of objects in the area around the vehicle and the distance to those objects can be detected.

[0032] In addition, the vehicle 10 may also be equipped with a camera. The camera can capture images of the environment in front of it from a specified angle. For example, the camera can be a monocular camera, a multi-view camera, etc.

[0033] Additionally, multiple millimeter-wave radars can be mounted on the vehicle 10 in a manner that surrounds the vehicle 10. For example, the vehicle 10 may be equipped with four millimeter-wave radars to cover the left front, right front, left rear, and right rear of the vehicle as detection ranges. The millimeter-wave radars can detect the distance to objects within their respective detection areas and the relative speed between the objects and the vehicle 10.

[0034] Furthermore, the vehicle 10 may also be equipped with a positioning device 12, such as a BeiDou positioning device or a Global Positioning System (GPS). The positioning device 12 can determine the current location of the vehicle 10.

[0035] In addition, the vehicle 10 may also be equipped with an Electronic Control Unit (ECU). Detection signals from at least one of the aforementioned LIDAR 11, millimeter-wave radar, and positioning device 12 are sent to the ECU. The ECU can detect and identify obstacles (such as roadblocks, moving objects, trees, adjacent vehicles, etc. around the vehicle 10) based on these signals. Furthermore, the ECU may be physically divided into multiple units according to function; these are collectively referred to as ECUs in this application.

[0036] It should be noted that although the mobile device is described as a car, this description is not limiting; various mobile devices are applicable, such as land robots and water robots. The circuit, method, and radar for detecting ambient light in the embodiments of this application can be applied to any one or more electronic devices that utilize LIDAR.

[0037] Figure 2 This is a schematic diagram illustrating another application scenario of the circuit, method, and radar for detecting ambient light, as shown in one embodiment of this application.

[0038] Figure 2 The illustration depicts an application scenario on urban roads. To enhance the aesthetics of building facades, some office buildings utilize a large amount of glass. This glass has high reflectivity, and the building surfaces are uneven. These factors result in brief bursts of intense reflected sunlight hitting the LiDAR receiver, affecting the LiDAR's ability to determine the intensity of reflected light from objects based on the received reflected laser light, thus impacting the LiDAR's detection accuracy. Furthermore, the headlights of oncoming vehicles also affect the LiDAR's detection accuracy.

[0039] In the aforementioned application scenarios such as assisted driving, autonomous driving, and intelligent transportation, the ability to quickly and accurately perceive the surrounding environment of mobile devices is a key point.

[0040] This example illustrates the concept of autonomous driving for vehicles. Based on vehicle location, obstacle, and road information perceived by the sensor system, road signal control is coordinated to improve road management quality and efficiency. Specifically, the information perceived by the sensor system can determine the appropriate autonomous vehicle decisions and adjust the safe distance between autonomous vehicles, thus enabling vehicles to drive safely and reliably on the road.

[0041] As one of the most important sensors for autonomous driving, LiDAR provides crucial information to decision-making systems in fields such as intelligent transportation and autonomous driving, including the location, size, and movement of traffic participants. Since LiDAR chips are essentially the eyes of an autonomous vehicle, improving the accuracy of LiDAR recognition results is extremely important, directly impacting the personal safety, property security, and even the lives of passengers and drivers.

[0042] However, the applicant discovered that in applications where ambient light detection is frequent, the LiDAR needs to be adjusted and controlled according to the environment to achieve better performance in terms of sunlight noise resistance and ranging capability. Related technologies utilize LiDAR to detect ambient light using ADC sampling. However, these technologies require ADC chips, which not only complicates circuit design but also increases overall cost and power consumption.

[0043] For the reasons mentioned above, this application aims to provide a technical solution that improves the anti-sunlight noise capability of lidar while maintaining low cost and low power consumption, thereby enhancing the accuracy of lidar detection results. This application effectively samples ambient light without using an ADC sampling method, simplifying circuit design and reducing cost and power consumption.

[0044] For example, in some embodiments, an avalanche photodiode (APD), a single-photon avalanche diode (SPAD), or other photosensitive sensors are used. After photoelectric conversion, the signal is processed by the circuit, and the signal is sampled and processed to finally obtain the ambient light result. This allows the influence of ambient light on the recognition result of the lidar to be filtered out based on the ambient light result.

[0045] Furthermore, in some embodiments, digital signals within M time units can be superimposed using a start-time alignment method to obtain an ambient light digital signal. This effectively utilizes historical and / or future light intensity information at the target time to correct the ambient light information at the target time. This embodiment effectively eliminates interference from abrupt ambient light changes while also effectively acquiring real-time ambient light information, thereby reducing interference from ambient light on the received reflected laser and improving the detection accuracy of the lidar.

[0046] Figure 3 This is a block diagram of a circuit for detecting ambient light, as shown in one embodiment of this application.

[0047] See Figure 3 The circuit 300 for detecting ambient light may include: a photosensitive element 310, an electrical signal conditioning circuit 320, a detection processing unit 330, and a digital processing unit 340.

[0048] The photosensitive element 310 is used to convert the received optical signal into a current signal. The photosensitive element 310 can be a photosensitive sensor, a sensitive device that responds to or converts external optical signals or light radiation. The photosensitive element 310 includes, but is not limited to: photosensitive sensors are among the most common sensors, and there are many types, including, but not limited to: phototubes, photomultiplier tubes, photoresistors, phototransistors, solar cells, infrared sensors, ultraviolet sensors, fiber optic photosensitive sensors, color sensors, charge-coupled devices (CCDs), and complementary metal-oxide-semiconductor (CMOS) image sensors. In some specific embodiments, the photosensitive element 310 can be an APD or a SPAD. It should be noted that the photosensitive spectrum of the photosensitive element 310 should be kept as consistent as possible with the spectrum of the LiDAR receiver to help improve the LiDAR's recognition performance.

[0049] Optical signals can be generated by the active emission of light from a light-emitting body, such as the light emitted by a light-emitting diode (LED) under electrical excitation, the light emitted by a laser (LD) under electrical or optical excitation, and light waves emitted by the sun. Optical signals can also be generated by reflected light, such as the light generated by the reflection of light from glass, metal, or mirrors.

[0050] The electrical signal conditioning circuit 320 is coupled to the photosensitive element and is used to convert the current signal into a voltage signal. This conversion facilitates subsequent signal processing. Furthermore, to further facilitate subsequent signal processing, an amplifier circuit can be integrated into the electrical signal conditioning circuit 320 to improve the signal-to-noise ratio. The current signal can be converted into a voltage signal using an IV-to-Voltage converter circuit. Specifically, the IV-to-Voltage converter can be implemented using a load resistor. For example, the current flowing through the load resistor is sampled, and the resistance value is fixed. Based on U = I˙R, a suitable amplifier can be designed. Then, the current signal can be converted into a voltage signal.

[0051] The detection processing unit 330 is coupled to the electrical signal conditioning circuit and is used to convert the voltage signal into a digital signal based on a voltage threshold. In this embodiment, the voltage threshold can be a preset threshold, which can be related to the aforementioned resistance value. For example, if the range of I is [0, 2] mA, and when I is 1 mA, if it is believed that the light intensity corresponding to the current 1 mA will affect the detection result of the lidar, then the voltage threshold can be set to R according to U = I˙R. For example, within a pulse time period, if the current voltage value is greater than or equal to the voltage threshold, then the pulse value of that pulse time period is 1; if the current voltage value is less than the voltage threshold, then the pulse value of that pulse time period is 0. A digital signal can be obtained in this way.

[0052] The digital processing unit 340 is coupled to the detection processing unit to process digital signals and obtain ambient light information. For example, the magnitude of the digital signal can characterize the intensity of the ambient light. Similarly, the number of pulses in the digital signal can characterize the duration of high intensity ambient light. The ambient light information obtained in this way can better represent the ambient light of the real environment, allowing for preprocessing of the light information collected by the lidar based on this information, thereby improving the accuracy of the recognition results.

[0053] In one specific embodiment, the photosensitive element 310 can be a photoelectric conversion element such as an APD or SPAD. The electrical signal conditioning circuit 320 amplifies or shapes the electrical signal output from the photosensitive element 310 to ensure the current or voltage is within a suitable range. The detection processing unit includes a comparator circuit and a corresponding data generation unit. The comparator circuit compares the electrical signal with a set threshold and outputs different states depending on whether the electrical signal exceeds the set threshold, thus converting it into a digital signal. For example, when the electrical signal exceeds the voltage threshold, a digital signal 1 is output; when the electrical signal is below the voltage threshold, a digital signal 0 is output. The digital processing unit receives the digital signal output from the detection processing unit, processes the received digital signal, and ultimately obtains the ambient light detection result.

[0054] In some embodiments, the photosensitive element is specifically used to convert ambient light signals received over M time units into current signals over M time units. A time unit may include one or more pulse cycles.

[0055] Accordingly, the digital processing unit is specifically used to superimpose digital signals within M time units to obtain ambient light digital signals.

[0056] For example, the photosensitive element 310 converts the ambient light signal received over M time units into a current signal over M time units. Then, the electrical signal conditioning circuit 320 converts the current signal over M time units into a voltage signal over M time units. Next, the detection processing unit 330 converts the voltage signal over M time units into a digital signal over M time units based on a voltage threshold. Then, the digital processing unit 340 superimposes the digital signals over M time units to obtain the ambient light digital signal.

[0057] In some embodiments, the detection processing unit 330 includes a threshold generation circuit, a comparison circuit, and a histogram generation circuit.

[0058] The threshold generation circuit is used to output a voltage threshold. Specifically, this threshold generation circuit can be implemented through a first storage circuit. For example, the first storage circuit is used to store the voltage threshold. The voltage threshold can be configured or fixed in the storage circuit, and is not limited here. For example, the voltage threshold can be a fixed value, such as 3, 10, 15, 30, 50, 100, etc., in units of microvolts, millivolts, volts, etc. The voltage threshold can also be a fixed numerical range, such as 3-10, 8-50, 20-60, 10-100, etc., in units of microvolts, millivolts, volts, etc.

[0059] See Figure 4The comparator circuit is coupled to both the electrical signal conditioning circuit and the threshold generation circuit. It compares the voltage signal with a voltage threshold (set threshold) for each of M time units to obtain a comparison result. For example, the comparator circuit includes a first threshold comparison unit, which may specifically include: a first logic circuit, a first input group, a first control group, and a first output group. The first input group is connected to a first storage circuit. The first logic circuit is used to: respond to the voltage signal input from the first control group, outputting a comparison result (pulse signal) from the first output group when the voltage value of the voltage signal exceeds the first threshold. See also... Figure 5 In a voltage signal, the time period during which the voltage value is greater than or equal to a set threshold corresponds to a high-level pulse, i.e., the digital signal "1"; the time period during which the voltage value is less than the set threshold corresponds to a low-level pulse, i.e., the digital signal "0". To compare two values, a combination of various logic operation circuits can be used, and no limitation is made here. Logic operations include, but are not limited to, "OR", "AND", "NOT", "NOR", "NAND", and "XOR".

[0060] The histogram generation circuit is coupled with the comparison circuit to generate a histogram based on the comparison result, thus obtaining a digital signal. Specifically, statistical results can be generated through histogram statistics.

[0061] It should be noted that the comparison circuit is implemented by a dedicated processor, such as a dedicated circuit consisting of AND gates, NOT gates, NAND gates, XOR gates, shift circuits, etc. The comparison calculation process can be implemented by a general-purpose processor, such as through software. The comparison circuit can also be implemented using a combination of dedicated and general-purpose processors.

[0062] Figure 6 This is a block diagram of another circuit for detecting ambient light, as shown in one embodiment of this application.

[0063] See Figure 6 The electrical signal conditioning circuit 320 may include a voltage conversion circuit and a first amplifier circuit.

[0064] The voltage conversion circuit (current-to-voltage circuit) is coupled to the photosensitive element and is used to convert the current signal from the photosensitive element into a voltage over M time units. The feedback element of the current-to-voltage circuit can be any one or a combination of resistors, capacitors, and inductors. In one specific embodiment, to convert the current signal into a voltage signal, a resistor of a certain resistance value can be connected in series at the current output terminal. The voltage across the resistor is the converted voltage signal. Furthermore, specific instruments can be used to improve the accuracy and reliability of the conversion result through electronic circuit conversion.

[0065] The first amplifier circuit, coupled to the voltage conversion circuit, amplifies the voltage-converted signal to obtain a voltage signal over M time units. The first amplifier circuit increases the output power of the signal. The amplifier circuit obtains its power source from the power supply to control the waveform of the output signal to match the input signal, but increases the amplitude of the output signal to obtain a stronger output signal than the input signal. For example, a common-emitter amplifier circuit or a common-collector amplifier circuit can be used.

[0066] In some embodiments, to further improve the signal-to-noise ratio of the output signal, noise in the ambient light digital signal can be reduced. Specifically, the digital processing unit is also used to filter the ambient light digital signal to obtain ambient light information.

[0067] In some embodiments, hardware filtering can be used to improve the stability of the ambient light digital signal and eliminate interference from instantaneous light intensity jumps. This embodiment, to simplify the hardware circuit, utilizes historical and / or future ambient light information at a specific moment to optimize the ambient light information at that particular moment. This reduces the jumps in ambient light information without increasing hardware complexity and ensures the accuracy of the ambient light information. Specifically, ambient light mainly originates from sunlight, and within a given time period, it should change continuously. Jumps are mainly caused by interference from specific reflected light (sunlight noise), etc. Furthermore, historical and / or future ambient light information has good consistency with the ambient light information at a specific moment and can reflect real-time changes in ambient light. Therefore, the ambient light information at a specific moment can be optimized based on historical and / or future ambient light information.

[0068] In some embodiments, the digital processing unit is specifically used to superimpose digital signals within M time units in a start-time aligned manner to obtain an ambient light digital signal.

[0069] In one specific embodiment, when detecting ambient light, the radar does not emit laser light, and the photosensitive element receives data in time units. For example, if each reception period is n, the total number of receptions is m. Then, the m receptions are superimposed in a time-aligned manner. Figure 7 As shown. Then, data based on time units is obtained, and this data is filtered to obtain ambient light data. This method of overlaying histograms from different time periods, followed by filtering, provides a more realistic result for ambient light, avoiding biases in different scenes.

[0070] Figure 8 This is a flowchart illustrating the process of detecting ambient light according to an embodiment of this application.

[0071] Please see also Figure 6 and Figure 8The process begins by activating the photosensitive element for measurement, then acquiring noise signals over time. During measurement, it checks if the acquisition time has been reached; if not, acquisition continues. Once the acquisition time is reached, the photosensitive element is deactivated and measurement stops, and the data is accumulated over time. Next, it checks if the preset number of acquisitions has been reached; if not, it restarts the photosensitive element and continues measurement. If the preset number of acquisitions has been reached, the data is filtered. The positions of the time-based data accumulation and the acquisition count check are interchangeable and do not affect the overall operation.

[0072] Figure 9 This is a schematic diagram illustrating data filtering according to an embodiment of this application. See also... Figure 9 Filtering can be applied to data accumulated from a single set. Various data filtering methods can be used, selected based on different measurement parameters. For example, amplitude limiting filtering can be used. Median filtering can be used, where a parameter is input N times consecutively, and the median value is selected as the current sample value. Moving average filtering can be used, employing a circular queue to store multiple sample values ​​in a first-in-first-out manner, calculating the arithmetic mean of the N data in the circular queue to obtain the valid sample value. Anti-pulse interference averaging filtering can be used, performing N consecutive samples, removing the maximum and minimum values, and then calculating the average of the remaining data as the valid sample value. Additionally, methods such as low-pass digital filtering and debouncing filtering can also be used.

[0073] Figure 10 This is another schematic diagram illustrating data filtering according to an embodiment of this application. See also... Figure 10 The filtering process can also be applied to the accumulated data from multiple sets. Specifically, the photosensitive element is also used to output P sets of current signals, each set of current signals including current signals within M time units. Correspondingly, the digital processing unit is specifically used to superimpose the P sets of ambient light digital signals corresponding to the P sets of current signals in a time-aligned manner to obtain the ambient light digital signal.

[0074] The above illustrates the method of determining ambient light information using histograms. Furthermore, to improve response speed, ambient light information can also be determined through signal accumulation.

[0075] Figure 11 This is a block diagram of another circuit for detecting ambient light, as shown in one embodiment of this application.

[0076] See Figure 11 The detection processing unit may include: a threshold generation circuit, a comparison circuit, and an accumulation circuit.

[0077] The threshold generation circuit is used to output the voltage threshold. Please refer to the relevant section on the threshold generation circuit above for details.

[0078] A comparator circuit, coupled to both an electrical signal conditioning circuit and a threshold generation circuit, compares the voltage signal with a voltage threshold value for each of M time units to obtain a comparison result. For example, the comparator circuit includes a second threshold comparison unit, which may specifically include a second storage circuit and a second threshold comparison circuit. The second storage circuit stores the second threshold. The second threshold can be a preset value or a range of values. The second threshold can be editable. The second threshold comparison circuit includes a second logic circuit, a second input group, a second control group, and a second output group. The second input group is connected to the second storage circuit. The second logic circuit is used to: respond to the voltage signal input from the second control group, output the comparison result from the second output group when the voltage signal exceeds the second threshold.

[0079] An accumulation circuit, coupled to a comparison circuit, is used to obtain a digital signal based on the accumulation operation of the comparison results. In this embodiment, an accumulation circuit is used instead of a histogram generation circuit. The accuracy of the histogram result is better than that of the result from the accumulation circuit. However, calculating a histogram requires relatively complex processing, while the accumulation circuit, compared to the histogram generation circuit, does not need to calculate the histogram; it only needs to perform accumulation operations such as counting, thus having the advantage of simple processing.

[0080] In this embodiment, photoelectric conversion is performed by photosensitive components, and after conditioning by electrical signal circuit, digital signals are output after detection processing. The digital processing unit accumulates the digital signals by number or duration, and selects whether to perform multiple samplings as needed to obtain the final data result.

[0081] In some embodiments, the accumulation circuit includes a counter and / or a carry chain.

[0082] The counter is coupled to the comparator circuit and is used to count the number of pulses to obtain a digital signal. Taking an adder counter as an example, a binary adder counter can be constructed using flip-flops. Alternatively, a subtractor counter can also be used for calculation. Counters can be implemented through a combination of various logic operation circuits. Taking software counting as an example, the operation `n&(n – 1)` can be repeatedly executed until `n` becomes 0. The operation `n&(n – 1)` removes the last 1 from `n`, making the last 1 of `n` become 0. For example, if `n = 11111`, the calculation process is as follows: `n = 11110`, count 1; `n = 11100`, count 2; `n = 11000`, count 3; `n = 10000`, count 4; `n = 00000`, count 5.

[0083] For example, the carry chain is coupled to the comparator circuit to calculate the result of adding voltage signals with their respective pulse widths over M time units. The carry chain provides fast carry functionality between dedicated adders in arithmetic mode. For instance, a parallel carry chain refers to the simultaneous generation of carry signals in parallel adders, also known as look-ahead carry or skip carry. Parallel carry chains can be divided into single-group and double-group types, also known as intra-group parallel and inter-group serial, and intra-group parallel and inter-group parallel, respectively. Single-group skip carry divides the n-bit full adder into several small groups, with carry within each group generated simultaneously, and serial carry between groups; this type of carry is also called intra-group parallel or inter-group serial. Double-group skip carry divides the n-bit full adder into several large groups, each containing several small groups. The most significant carry of each small group within each large group is generated simultaneously. Serial carry is used between large groups.

[0084] Figure 12 This is a flowchart illustrating the accumulation of quantities according to an embodiment of this application.

[0085] The process of accumulating counts is illustrated below; the count is incremented by 1 for each high-level pulse. See also... Figure 12 First, the photosensitive element is activated for measurement. Then, noise signals are acquired over time, and the acquisition time is checked. If the acquisition time has not been reached, acquisition continues. After the acquisition time is reached, the photosensitive element measurement is deactivated, and the data is accumulated by the number of pulses. The number of acquisitions is then checked again. If the number of acquisitions has not been reached, the photosensitive element is activated again. If the number of acquisitions has been reached, the data is filtered. Filtering can be performed on a single set of accumulated data, or on multiple sets of accumulated data.

[0086] Figure 13 This is a flowchart illustrating the accumulation of width values ​​according to an embodiment of this application.

[0087] The process of accumulating pulse width values ​​is illustrated below. The pulse width value refers to the duration of the pulse exceeding a threshold after detection, as in a detection processing unit designed as a comparator circuit; similarly, in a detection processing unit designed as an ADC circuit, it refers to the duration of the digital electrical signal exceeding a digitally set threshold. Specifically, each time a high-level pulse is detected, its duration is accumulated. See [link to documentation]. Figure 13First, the photosensitive element measurement is activated. Then, noise signals are acquired over time, and it is determined whether the acquisition time has been reached. If not, acquisition continues. After the acquisition time is reached, the photosensitive element measurement is deactivated, and the data is accumulated using a width value. Next, it is determined whether the number of acquisitions has been reached. If not, the photosensitive element is activated again. If the number of acquisitions has been reached, the data is filtered. Filtering can be performed on a single set of accumulated data or on multiple sets of accumulated data. It should be noted that the positions of the data accumulation by pulse count and the acquisition time determination modules can be interchanged without affecting the overall operation.

[0088] Figure 14 This is a schematic diagram illustrating the accumulation of quantities in one embodiment of this application.

[0089] See Figure 14 ,exist Figure 14 The number of width values ​​within the sampling time is counted, as shown in the figure as n, and the ambient light information value is n. Multiple measurements result in multiple environmental data. One approach to processing multiple samples is to accumulate the data values ​​from multiple samples and then filter them to obtain the ambient light data. Another approach is to not accumulate the multiple samples but directly perform data filtering to obtain the ambient light data.

[0090] Figure 15 This is a schematic diagram illustrating the accumulation of width values ​​according to an embodiment of this application.

[0091] See Figure 15 ,exist Figure 15 After a single measurement, the width values ​​of all digital signals within that acquisition time are summed to obtain w = w1 + w2 + … + w n Where n is an integer greater than or equal to 1. Multiple measurements will result in multiple environmental results. One approach to processing multiple samples is to accumulate the data values ​​from multiple samples and then filter them to obtain ambient light data. Another approach is to perform direct data filtering instead of accumulating the multiple samples to obtain the ambient light data.

[0092] In some embodiments, the electrical signal conditioning circuit can be optimized to improve the quality of the voltage signal output by the electrical signal conditioning circuit, such as by increasing the signal-to-noise ratio.

[0093] For example, in addition to voltage conversion circuit and first amplifier circuit, electrical signal conditioning circuit may also include: filter circuit and second amplifier circuit.

[0094] Please see also Figure 11The filter circuit is coupled to the first amplifier circuit and is used to filter the voltage signal within M time units to obtain the filtered voltage signal. The filter circuit may include components such as capacitors.

[0095] The second amplifier circuit is coupled to the filter circuit and is used to amplify the filtered voltage signal to obtain a voltage signal over M time units. The specific structure of the second amplifier circuit can be referred to the first amplifier circuit, and will not be described in detail here.

[0096] The embodiments of this application can be applied to lidar systems, enabling the detection of ambient light and subsequent adjustment and control of the lidar based on the environment. This results in improved performance, including enhanced resistance to sunlight noise and improved ranging capabilities, thereby improving user safety and property security.

[0097] Another aspect of this application provides a method for detecting ambient light.

[0098] Figure 16 This is a schematic flowchart illustrating a method for detecting ambient light according to an embodiment of this application.

[0099] See Figure 16 The method for detecting ambient light may include operations S1610 to S1640.

[0100] In operation S1610, the received optical signal is converted into a current signal. Specifically, a photosensitive element can be used to convert the optical signal into a current signal.

[0101] In operation, S1620 converts the current signal into a voltage signal. For details, refer to the relevant section on the electrical signal conditioning circuit.

[0102] In operation S1630, the voltage signal is converted into a digital signal based on the voltage threshold. For details, please refer to the relevant section of the detection processing unit.

[0103] The S1640 processes digital signals to obtain ambient light information. For details, please refer to the relevant section of the digital processing unit description.

[0104] In some embodiments, the ambient light signal received within M time units is converted into a current signal within M time units, so that the digital signals within M time units can be superimposed to obtain an ambient light digital signal.

[0105] In some embodiments, signal superposition is performed by superimposing digital signals within M time units in a start-time aligned manner to obtain an ambient light digital signal.

[0106] In some embodiments, the above method may further include the following operation: processing the received laser signal based on ambient light information to reduce interference from ambient light on the laser signal. Eliminating interference from ambient light on the laser signal based on digital ambient light signals can effectively improve the accuracy of the processed data of the lidar, thereby improving the accuracy of the recognition results.

[0107] Another aspect of this application provides an apparatus for detecting ambient light.

[0108] The device for detecting ambient light may include a photoelectric conversion module, a current-to-voltage conversion module, a digital voltage signal module, and a digital processing module.

[0109] The photoelectric conversion module is used to convert the received optical signal into a current signal.

[0110] The current-to-voltage module is coupled to the photoelectric conversion module and is used to convert current signals into voltage signals.

[0111] The digital voltage signal module is coupled with the current-to-voltage module to convert voltage signals into digital signals based on a voltage threshold.

[0112] The digital processing module is coupled to the digital voltage signal module to process digital signals and obtain ambient light information.

[0113] Another aspect of this application provides a radar.

[0114] Figure 17 This is a schematic diagram of the structure of a radar according to an embodiment of this application.

[0115] See Figure 17 The radar 1700 may include the ambient light detection circuit shown above, which is used to obtain ambient light information. For example, the ambient light detection circuit may be disposed on a circuit board 1710, which may have multiple chips or processors, such as a central control chip. The circuit board 1710 may be disposed in a housing 1720. For example, the processor is coupled to the ambient light detection circuit and is used to process the received laser signal based on the ambient light information to reduce the interference of ambient light on the laser signal.

[0116] The radar can be a lidar or similar type of radar that may be affected by ambient light intensity. The radar can be either scanning or non-scanning. The following explanation uses a scanning lidar as an example.

[0117] For example, MEMS-type LiDAR can dynamically adjust its scanning mode to focus on specific objects, collect detailed information about smaller objects at a distance, and identify them. MEMS-type LiDAR has a relatively small inertial torque, allowing it to move quickly, fast enough to track 2D scanning patterns in less than a second.

[0118] For example, Flash-type lidar can quickly record the entire scene, avoiding various problems caused by the movement of the target or lidar during scanning. The lidar system uses a miniature sensor array to collect laser beams reflected from different directions.

[0119] For example, a row of transmitters on a phased array lidar can change the emission direction of the laser beam by adjusting the relative phase of the signals.

[0120] For example, mechanical rotating lidar is one of the earliest types of lidar developed and its technology is relatively mature. However, the structure of mechanical rotating lidar systems is very complex, and the prices of each core component are quite high. These components mainly include lasers, scanners, optical components, photodetectors, receiver ICs, and positioning and navigation devices.

[0121] Taking MEMS solid-state lidar as an example, since MEMS solid-state lidar scans using the simple harmonic vibration of a galvanometer, its scanning path, in terms of spatial order, can be a scanning field of view that moves back and forth between the slow axis (top to bottom) and the fast axis (left to right). Therefore, the detection range of MEMS solid-state lidar is divided by the field of view angle corresponding to the slow axis. For example, the vertical field of view angle corresponding to the slow axis of a MEMS solid-state lidar is -13° to 13°.

[0122] Taking mechanical lidar as an example of a scanning sensor, mechanical lidar achieves scanning by rotating the optical system 360 degrees using a mechanical drive device, resulting in a cylindrical detection area centered on the lidar. Therefore, the detection range corresponding to a 360° rotation of the mechanical lidar is the detection range corresponding to one frame of data. Thus, the detection range of a mechanical lidar in one cycle is generally divided by the degree of rotation.

[0123] For non-scanning LiDAR, the image is processed by the internal photosensitive component circuit and control component and converted into a digital signal that can be recognized by the computer. Then, it is input to the computer via a parallel port or USB connection, and the software then restores the image.

[0124] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated further here.

[0125] Another aspect of this application provides an electronic device.

[0126] Figure 18 This is a schematic diagram of the structure of an electronic device shown in an embodiment of this application.

[0127] See Figure 18 The electronic device 1800 may include a memory 1810 and a processor 1820. Furthermore, the electronic device 1800 may also be equipped with at least one of the following: a circuit for detecting ambient light or a radar.

[0128] The processor 1820 can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0129] Memory 1810 may include various types of storage units, such as system memory, read-only memory (ROM), and permanent storage devices. ROM may store static data or instructions required by processor 1820 or other modules of the computer. Permanent storage devices may be read-write storage devices. Permanent storage devices may be non-volatile storage devices that retain stored instructions and data even when the computer is powered off. In some embodiments, permanent storage devices use mass storage devices (e.g., magnetic or optical disks, flash memory) as permanent storage devices. In other embodiments, permanent storage devices may be removable storage devices (e.g., floppy disks, optical drives). System memory may be a read-write storage device or a volatile read-write storage device, such as dynamic random access memory. System memory may store some or all of the instructions and data required by the processor during operation. Furthermore, memory 1810 may include any combination of computer-readable storage media, including various types of semiconductor memory chips (e.g., DRAM, SRAM, SDRAM, flash memory, programmable read-only memory), and disks and / or optical disks may also be used. In some embodiments, the memory 1810 may include a removable storage device that is readable and / or writable, such as a laser disc (CD), a read-only digital multifunction optical disc (e.g., DVD-ROM, dual-layer DVD-ROM), a read-only Blu-ray disc, an ultra-high density optical disc, a flash memory card (e.g., SD card, mini SD card, Micro-SD card, etc.), a magnetic floppy disk, etc. Computer-readable storage media do not contain carrier waves or transient electronic signals transmitted wirelessly or via wired connections.

[0130] The memory 1810 stores executable code, which, when processed by the processor 1820, can cause the processor 1820 to execute part or all of the methods described above.

[0131] Furthermore, the method according to this application can also be implemented as a computer program or computer program product, which includes computer program code instructions for performing some or all of the steps in the method described above.

[0132] Alternatively, this application may be implemented as a computer-readable storage medium (or a non-transitory machine-readable storage medium or a machine-readable storage medium) storing executable code (or computer program or computer instruction code) thereon, which, when executed by a processor of an electronic device (or server, etc.), causes the processor to perform part or all of the steps of the methods described above according to this application.

[0133] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A circuit for detecting ambient light, characterized in that include: Photosensitive components are used to convert received optical signals into electrical signals; An electrical signal conditioning circuit, coupled to the photosensitive element, is used to convert the current signal into a voltage signal; The detection processing unit, coupled to the electrical signal conditioning circuit, is used to convert the voltage signal within M time units into a digital signal within the M time units based on a voltage threshold. A digital processing unit, coupled to the detection processing unit, is used to superimpose the digital signals within the M time units in a start-time aligned manner to obtain an ambient light digital signal.

2. The circuit according to claim 1, characterized in that: The photosensitive element is specifically used to convert the ambient light signal received within M time units into a current signal within the same M time units.

3. The circuit according to claim 2, characterized in that: The photosensitive element is also used to output P groups of current signals, each group of current signals including the current signal within the M time units; The digital processing unit is specifically used to superimpose the P groups of ambient light digital signals corresponding to the P groups of current signals in a time-aligned manner to obtain ambient light digital signals.

4. The circuit of claim 2, wherein, The electrical signal conditioning circuit includes: A voltage conversion circuit, coupled to the photosensitive element, is used to convert the current signal from the photosensitive element into a voltage within the M time units. The first amplifier circuit, coupled to the voltage conversion circuit, is used to amplify the voltage-converted signal to obtain the voltage signal within the M time units.

5. The circuit of claim 1, wherein, The detection processing unit includes: A threshold generation circuit is used to output the voltage threshold. A comparison circuit, coupled to the electrical signal conditioning circuit and the threshold generation circuit respectively, is used to compare the voltage signal with the voltage threshold in each of the M time units to obtain a comparison result; A histogram generation circuit, coupled to the comparison circuit, is used to generate a histogram based on the comparison result to obtain the digital signal.

6. The circuit of claim 4, wherein, The detection processing unit includes: A threshold generation circuit is used to output the voltage threshold. A comparison circuit, coupled to the electrical signal conditioning circuit and the threshold generation circuit respectively, is used to compare the voltage signal with the voltage threshold in each of the M time units to obtain a comparison result; An accumulation circuit, coupled to the comparison circuit, is used to obtain the digital signal based on the accumulation operation on the comparison result.

7. The circuit of claim 6, wherein, The accumulation circuit includes: A counter, coupled to the comparison circuit, is used to count the number of pulses to obtain the digital signal; and / or The carry chain, coupled to the comparison circuit, is used to calculate the summation result of the pulse widths of the voltage signals within the M time units.

8. The circuit of claim 4, wherein, The electrical signal conditioning circuit further includes: A filtering circuit, coupled to the first amplifier circuit, is used to filter the voltage signal within the M time units to obtain a filtered voltage signal. The second amplifier circuit, coupled to the filter circuit, is used to amplify the filtered voltage signal to obtain the voltage signal within the M time units.

9. A radar, characterized by include: The circuit for detecting ambient light according to any one of claims 1 to 8 is used to obtain ambient light information; The processor, coupled to the circuit for detecting ambient light, is used to process the received laser signal based on the ambient light information to reduce the interference of ambient light on the laser signal.

10. A method of detecting ambient light, characterized by, include: The received optical signal is converted into an electrical signal; Convert the current signal into a voltage signal; Based on a voltage threshold, the voltage signal within M time units is converted into a digital signal within the same M time units. The digital signals within the M time units are superimposed in a manner aligned with the start time to obtain the ambient light digital signal.

11. The method of claim 10, wherein, Also includes: The received laser signal is processed based on the ambient light information to reduce the interference of ambient light on the laser signal.

12. A computer readable storage medium having stored thereon computer instructions, wherein, When the instruction is executed by the processor, it implements the steps of the method as described in any one of claims 10-11.

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