RU2793241C2 - Optical systems and methods for their control - Google Patents

Abstract

FIELD: light detection and ranging systems (LiDAR, Light Detection and Ranging,).
SUBSTANCE: technology relates in particular to methods and systems for selective scanning of objects in areas of interest. The lidar system and the method of controlling the optical system involve the action of the controller on the light source to emit light pulses with the first pulse repetition rate, the direction of the light pulses by the scanning device connected to the controller from the optical system, detection by at least one sensor connected to the controller, of a light signal reflected from at least one object in the field of view of the optical system, the controller determines the signal-to-noise ratio of the reflected light signal, the controller determines the difference between the signal-to-noise ratio and the threshold signal-to-noise ratio, and the controller influences the light source for emission, pulses light with a second pulse repetition rate different from the first pulse repetition frequency, based on this difference.

EFFECT: improving the quality of spatial localization of objects by a lidar system while limiting the influence of signal quality.

12 cl, 4 dwg

Description

The field of technology to which the invention belongs

[01] The present technology generally relates to light detection and ranging systems (LiDAR, Light Detection and Ranging,) and in particular to methods and systems for selective scanning of objects in areas of interest.

State of the art

[02] Lidar systems (light detection and ranging systems, also called lidars) are widely used in self-driving (autonomous) vehicles. Lidar systems measure the distance between the system and surrounding objects by illuminating the surrounding area with light and capturing the light reflected from one or more objects in this surrounding area.

[03] In a typical time-of-flight (ToF, Time of Flight) lidar system, a light source emits a plurality of pulsed narrow laser beams to scan the field of view. Light reflected from an object and/or scattered by an object in the field of view is received by the detection unit of the lidar system to determine the location of the object. Time-of-flight systems measure the time between (1) the emission of a light beam and (2) the detection of a scattered light beam to determine the distance to an object.

[04] The reflected beams received by the lidar are processed to generate data points by a central computer, with each beam pulse displayed as one data point in a point cloud, representing the environment as a three-dimensional map. The 3D map is more or less detailed and accurate depending on the density or update rate of the point cloud. In general, the higher the sampling rate in the field of view, the more detailed and accurate the 3D map will be.

[05] The frequency of pulses emitted by the lidar system and the corresponding number of points is usually limited by several factors. For example, for some laser sources in lidars, the radiation frequency (maximum pulse frequency) may be limited, above which the power of the laser source may decrease. In such a case, the power of the light pulses emitted by the laser is reduced and the power of the received reflected light is reduced accordingly. For example, for objects with low reflectivity, the lower power of laser pulses may not be sufficient to obtain a signal suitable for the formation of a three-dimensional map.

[06] Therefore, systems and methods are required to eliminate, reduce or overcome the limitations of known technical solutions.

Disclosure of invention

[07] The developers of the present technology have found certain solutions to eliminate, reduce and/or overcome at least some of the limitations of the prior art.

[08] In accordance with a broad aspect of the present technology, a time-of-flight lidar system with multiple scan modes is implemented to optimize the scan rate depending on the density of objects that generate strong signals. In accordance with non-limiting embodiments of the present technology, the lidar system includes a light source, which is a laser source connected to a fiber amplifier. In some cases, the fiber amplifier is a doped fiber amplifier, in particular an Erbium Doped Fiber Amplifier (EDFA). For example, in a lidar system with an EDFA amplifier, pulses emitted by a laser source are amplified by excited erbium ions in the fiber core. After the shaped pulse of the laser beam is emitted by the lidar system, it takes some time to pump the light source, which is determined by the population inversion rate in the doped fiber amplifier. Thus, when the pulse frequency (i.e., the pulse emission frequency) exceeds the pumping frequency (population inversion), the power of the pulses emitted by the light source decreases due to incomplete pumping of the amplifier.

[09] In accordance with non-limiting embodiments of the present technology, a signal-to-noise ratio is determined for one or more areas of the system field of view and compared with a predetermined threshold signal-to-noise ratio to control the lidar system in one of a variety of scan modes. For areas of the field of view in which the signal-to-noise ratio is above the threshold value, the pulse rate of the output beam can be increased to increase the spatial resolution (or update rate) of the 3D map of that area. Using the present technology, the pulse frequency can be increased to a value that exceeds the population inversion rate of the doped fiber amplifier if the signal-to-noise ratio exceeds a threshold value. Thus, even at a lower power of the light pulse in the identified area, more frequent sampling is performed by radiation until the population inversion in the amplifier is completed. Since a low power light pulse is directed only to areas with a sufficiently high signal-to-noise ratio at the initial power, it is expected that in these areas and at low power an acceptable signal quality is formed. Accordingly, in areas with a signal-to-noise ratio not exceeding the threshold value, oversampling is not performed in order to avoid receiving a too weak reflected signal due to a decrease in the power of the light pulse. This balances spatial resolution and signal strength.

[010] In accordance with the first broad aspect of the present technology, a method for controlling an optical system is implemented. The method includes exposing the light source by the controller to emit light pulses with a first pulse repetition rate, directing the light pulses by a scanning device connected to the controller from the optical system, detecting by at least one sensor connected to the controller a light signal reflected from the at least one object in the field of view of the optical system, the controller determines the signal-to-noise ratio of the reflected light signal, the controller determines the difference between the signal-to-noise ratio and the threshold signal-to-noise ratio, and the controller influences the light source to emit light pulses with a second pulse repetition rate, different from the first pulse repetition rate, based on this difference.

[011] In some embodiments, the method further includes determining by the controller that the signal-to-noise ratio is greater than a threshold signal-to-noise ratio, wherein the second pulse rate is greater than the first pulse rate.

[012] In some embodiments of the invention, the second pulse repetition rate is greater than the pumping frequency of the light source.

[013] In some embodiments, the signal-to-noise ratio is a first signal-to-noise ratio, and the method after exposing the light source to emit light pulses at a second pulse rate further includes determining, by the controller, a second signal-to-noise ratio, determining by the controller that that the second signal-to-noise ratio is less than the threshold signal-to-noise ratio, and causing the controller to act on the light source to emit light pulses at a third pulse rate different from the second pulse rate.

[014] In some embodiments, the third pulse rate is equal to the first pulse rate.

[015] In some embodiments of the invention, determining the signal-to-noise ratio of the reflected light signal includes determining, by the controller, the signal-to-noise ratio of the subzone corresponding to the signal-to-noise ratio of the part of the reflected signal coming from the region of interest within the field of view, determining the difference between the signal ratio /noise and the signal-to-noise ratio threshold includes determining by the controller that the signal-to-noise ratio of the subzone is greater than the threshold signal-to-noise ratio, and the controller's action on the light source to emit light pulses with a second pulse repetition rate includes the controller's action on the source light for emitting pulses of light with a second pulse repetition rate when scanning this area of interest, if the signal-to-noise ratio of the subzone exceeds the threshold signal-to-noise ratio.

[016] In some embodiments, determining a subzone signal-to-noise ratio includes determining, by a controller, a plurality of subzone signal-to-noise ratios for a plurality of regions of interest, determining that the signal-to-noise ratio of the subzone is greater than a threshold signal-to-noise ratio, includes determining at least one subzone signal-to-noise ratio of the plurality of sub-zone signal-to-noise ratios is greater than the threshold signal-to-noise ratio, wherein at least one sub-zone signal-to-noise ratio corresponds to signals received in the region of interest from the plurality of regions of interest, and causing the controller to act on the light source to emit pulses of light at a second pulse rate while scanning the region of interest if at least one signal-to-noise ratio exceeds a threshold signal-to-noise ratio.

[017] In accordance with the second broad aspect of the present technology, a method for controlling an optical system is implemented. The method includes the action by the controller on the light source to emit light pulses with a first pulse repetition rate, the scanning unit connected to the controller directs the light pulses from the optical system, detection by at least one sensor connected to the controller of a plurality of light signals reflected in field of view of the optical system, consisting of a plurality of areas of interest, controlling the light source controller, at least in part, based on a plurality of reflected light signals, while the control for the area of interest includes determining the signal-to-noise ratio of the reflected light signal of this area of interest by the controller, determining by the controller the difference between the signal-to-noise ratio and the threshold signal-to-noise ratio, causing the controller to act on the light source to emit light pulses with a second pulse repetition rate different from the first pulse repetition frequency, based on the signal difference when scanning this region of interest.

[018] In some embodiments, the signal-to-noise ratio is greater than the threshold signal-to-noise ratio, and the second pulse rate is greater than the first pulse rate.

[019] In some embodiments, the region of interest is the first region of interest, the signal-to-noise ratio is the first signal-to-noise ratio, and for the second region of interest, the method further includes determining, by the controller, a second signal-to-noise ratio of the light signal reflected in the second region of interest. area, determining by the controller the difference between the second signal-to-noise ratio and the threshold signal-to-noise ratio, and causing the controller to act on the light source to emit light pulses with a third pulse repetition rate different from the first pulse repetition rate, based on this difference when scanning the second region of interest.

[020] In some embodiments, the third pulse rate is equal to the second pulse rate.

[021] In accordance with another broad aspect of the present technology, a system is implemented comprising a light source, a scanning unit capable of directing light from a light source, a receiving unit capable of receiving light reflected from objects in the surrounding space and containing at least one sensor, and also a controller connected to at least the scanning unit and the receiving unit and capable of executing instructions stored therein, including the action of the controller on the light source to emit light pulses with a first pulse repetition rate, the direction of the light pulses by the scanning device connected to the controller from the optical system , detection by at least one sensor connected to the controller of a light signal reflected from at least one object in the field of view of the optical system, determination by the controller of the signal-to-noise ratio of the reflected light signal, determination by the controller of the difference between the signal-to-noise ratio and the threshold signal ratio -noise and the effect of the controller on the light source to emit light pulses with a second pulse repetition rate different from the first pulse repetition rate, based on this difference.

[022] In some embodiments, the second pulse rate is greater than the first pulse rate.

[023] In some embodiments of the invention, the light source includes a laser connected to the controller and a doped fiber amplifier.

[024] In some embodiments, the second pulse rate is greater than the first pulse rate and greater than the pump frequency of the doped fiber amplifier.

[025] In accordance with another broad aspect of the present technology, a lidar system is implemented, containing a light source, a scanning unit capable of directing light pulses from a light source, a receiving unit capable of receiving light signals reflected from objects in the surrounding space and containing at least one a sensor; and a controller connected to at least the scanning unit and the receiving unit and capable of performing the method described above in accordance with certain non-limiting embodiments of the invention.

[026] In the context of this description, the term "light source" generally refers to any device capable of emitting a signal, for example, in the form of a beam, including a beam of light with one or more wavelengths in the electromagnetic spectrum. In one embodiment of the invention, the light source may be a laser source. Thus, the light source may comprise a laser, such as a solid state laser, a laser diode, a high power laser, or an alternative light source, such as a light emitting diode light source. Some (non-limiting) examples of a laser source are a Fabry-Perot diode laser, a quantum well laser, a Distributed Bragg Reflector (DBR) laser, a Distributed FeedBack (DFB) laser, a fiber laser, or surface-emitting laser with a vertical cavity (VCSEL, Vertical-Cavity Surface-Emitting Laser). In addition, the laser source can emit light in various formats, such as light pulses, continuous oscillations, quasi-continuous oscillations, etc. In some non-limiting examples, the laser source may comprise a laser diode capable of emitting light at a wavelength in the range of approximately 650-1150 nm. Alternatively, the light source may comprise a laser diode capable of emitting light in the wavelength range of about 800-1000 nm, about 850-950 nm, about 1300-1600 nm, or any other suitable range. Unless otherwise indicated, the term "approximately" in relation to a numerical value means a deviation not exceeding 10% from the specified value.

[027] In the context of this description, the term "output beam" can also refer to a beam of radiation, for example, to a beam of light generated by a radiation source and directed towards a region of interest. The output beam can be characterized by one or more parameters, such as radiation duration, beam angular divergence, wavelength, instantaneous power, photon density at different distances from the light source, average power, beam power density, beam width, radiation pulse repetition rate, sequence of emitted pulses, duty cycle, wavelength, phase, etc. The output beam may be unpolarized or randomly polarized, may not have a specific or permanent polarization (eg, the polarization may change over time), or may have a specific polarization (eg, linear, elliptical, or circular polarization).

[028] In the context of this description, the "input beam" is radiation or light entering the system, usually after reflection from one or more objects in the region of interest. The input beam may also be referred to as a radiation beam or a light beam. The term "reflection" means that at least a portion of the output beam is incident on and reflected from one or more objects in the region of interest. The input beam may be characterized by one or more parameters such as time of flight (i.e., time from emission to detection), instantaneous power (i.e., power signature), mean backpulse power, distribution of photons in the signal over the backpulse period, and etc. Depending on the particular use, some of the radiation or light in the input beam may come from sources other than the reflected output beam. For example, at least some of the input beam may represent a glitch of light noise from the surrounding space (including scattered sunlight) or from other light sources external to the present system.

[029] In the context of this description, the term "ambient space" of a vehicle refers to the area or volume around the vehicle, including part of its current ambient space, available for scanning using one or more sensors installed on this vehicle, for example, to form a three-dimensional map of such surrounding space or to detect objects in it.

[030] In the context of this description, the term "region of interest" can broadly mean the part of the observed surrounding space of the lidar system in which one or more objects can be detected. It should be noted that the area of interest of the lidar system can be affected by various conditions, such as the orientation of the lidar system (for example, the direction of the optical axis of the lidar system), the position of the lidar system in the surrounding space (for example, distance above the ground, terrain and obstacles in the immediate vicinity from the system), operating parameters of the lidar system (eg, radiation power, computational settings, specified operating angles), etc., but not limited to them. The area of interest of the lidar system can be defined, for example, by a flat or solid angle. In one example, the area of interest can also be defined by a range (eg, up to about 200 m).

[031] As used herein, a "server" is a computer program executing on appropriate hardware and capable of receiving requests over a network (eg, from electronic devices) and executing or initiating those requests. The corresponding hardware may be implemented as a single computer or a single computer system, which is not essential to the present technology. In this context, the expression "server" does not mean that every task (e.g. received command or request) or some particular task is received, executed or started by the same server (i.e. the same software and/or hardware ). This expression means that any number of software or hardware can receive, send, execute or start the execution of any task or request or the results of any tasks or requests. All of these software and hardware may be a single server or multiple servers, both of which are meant by the expression "at least one server".

[032] As used herein, an "electronic device" is any computer hardware capable of executing software suitable for a given task. In the context of this description, the term "electronic device" implies that the device can function as a server for other electronic devices, however, this is not required for the present technology. Thus, some (non-limiting) examples of electronic devices include self-driving devices, personal computers (desktops, laptops, netbooks, etc.), smartphones and tablets, and network equipment such as routers, switches and gateways. It should be understood that in this context, the fact that a device functions as an electronic device does not mean that it cannot function as a server for other electronic devices.

[033] In the context of this description, the expression "information" includes information of any kind or type that can be stored in a database. Thus, information includes visual works (for example, maps), audiovisual works (for example, images, films, sound recordings, presentations, etc.), data (for example, location data, weather data, traffic data, numerical data, etc.), text (such as but not limited to opinions, comments, questions, messages, etc.), documents, spreadsheets, etc.

[034] In the context of this description, the term "database" means any structured set of data, regardless of its specific structure, database management software, or computer hardware for storing this data, using it, or otherwise providing its use. The database may reside on the same hardware as the process for storing or using the information stored in the database, or the database may reside on separate hardware such as a specialized server or multiple servers.

[035] In the context of this description, the numerals "first", "second", "third", etc. are used only to indicate the difference between the nouns they refer to, but not to describe any specific relationship between these nouns. Also, as occurs herein in another context, reference to a "first" element and a "second" element does not preclude that the two elements may in fact be the same element.

[036] Each embodiment of the present technology relates to at least one of the above goals and/or aspects, but not necessarily all of them. It should be understood that some aspects of the present technology, associated with an attempt to achieve the above goal, may not meet this goal and/or may meet other goals not explicitly mentioned here.

[037] Additional and/or alternative features, aspects, and advantages of embodiments of the present technology are contained in the following description, in the accompanying drawings, and in the claims.

Brief description of the drawings

[038] These and other features, aspects, and advantages of the present technology are contained in the following description, in the appended claims, and in the following drawings.

[039] In FIG. 1 is a schematic representation of an example computer system suitable for implementing certain non-limiting embodiments of the present technology.

[040] In FIG. 2 is a schematic representation of a networked computing environment suitable for use with certain non-limiting embodiments of the present technology.

[041] In FIG. 3 is a schematic representation of an example of a lidar system implemented in accordance with some non-limiting embodiments of the present technology.

[042] In FIG. 4 is a flowchart of the control method for the lidar system shown in FIG. 3 implemented in accordance with certain non-limiting embodiments of the present technology.

Implementation of the invention

[043] The examples and conventions provided herein are intended to provide a better understanding of the principles of the present technology, and not to limit its scope to such specifically given examples and terms. It is obvious that specialists in the art are able to develop various methods and devices that are not explicitly described or shown, but implement the principles of the present technology within its essence and scope.

[044] In addition, to facilitate a better understanding, the following description may contain simplified implementations of the present technology. Those skilled in the art will appreciate that other embodiments of the present technology may be significantly more complex.

[045] In some cases, useful examples of modifications to the present technology are provided. They contribute to understanding, but also do not define the scope or boundaries of the present technology. The presented list of modifications is not exhaustive and the person skilled in the art can develop other modifications within the scope of this technology. In addition, if modifications are not described in some cases, this does not mean that they are impossible and / or that the description contains the only possible implementation of one or another element of the present technology.

[046] The description of principles, aspects, and embodiments of the present technology, as well as their specific examples, is intended to cover their structural and functional equivalents, whether they are currently known or will be developed in the future. For example, those skilled in the art will appreciate that any block diagrams described herein correspond to conceptual representations of illustrative circuit diagrams that implement the principles of the present technology. It should also be understood that any flowcharts, process diagrams, state transition diagrams, pseudocodes, etc. correspond to various processes that may be represented on a computer-readable physical storage medium and may be executed by a computer or processor, whether such computer or processor is explicitly shown or not.

[047] The functions of the various elements shown in the drawings, including any functional block designated as "processor", can be implemented using specialized hardware, as well as hardware capable of executing the corresponding software. If a processor is used, these functions may be performed by a single dedicated processor, a single shared processor, or multiple individual processors, some of which may be shared. In addition, explicit use of the term "processor" or "controller" should not be construed as referring solely to the hardware capable of executing the software and may refer to, but is not limited to, digital signal processor (DSP) hardware, network processor, ASIC (ASIC), Field Programmable Gate Array (FPGA), Software ROM, RAM and NVRAM. Other general purpose and/or custom hardware may also be contemplated.

[048] Software modules, or simply modules that are intended to be implemented in software, may be represented here as any combination of flowchart elements or other elements that indicate the steps of a process and/or contain a textual description. Such modules may be implemented in hardware, as shown or implied.

[049] In the following, in view of the principles set forth above, some non-limiting examples are discussed illustrating various embodiments of aspects of the present technology.

[050] Computer system

[051] In FIG. 1 is a schematic representation of a computer system 100 suitable for use with certain non-limiting embodiments of the present technology. Computer system 100 includes various hardware elements including one or more single or multi-core processors, collectively represented by processor 110, solid state drive 120, and memory 130, which may be RAM or any other form of memory.

[052] Communication between elements of computer system 100 may be via one or more internal and/or external buses (not shown), such as a PCI bus, USB bus, IEEE 1394 FireWire bus, SCSI bus, Serial-ATA bus, etc. to which various hardware elements are electronically connected. In accordance with embodiments of the present technology, the solid state drive 120 stores program instructions suitable for loading into memory 130 and execution by processor 110 to determine the presence of an object. For example, software instructions may be included in a vehicle control application executed by processor 110. It should be noted that computer system 100 may include additional and/or optional elements (not shown), such as network communication modules, location modules, etc. .d.

[053] Networked Computing Environment

[054] In FIG. 2 depicts a networked computing environment 200 suitable for use with certain non-limiting embodiments of the present technology. Networked computing environment 200 includes an electronic device 210 associated with vehicle 220 and/or a user (not shown) that is associated with vehicle 220 (specifically, an operator of vehicle 220). The networked computing environment 200 also includes a server 235 connected to the electronic device 210 via a communication network 240 (eg, via the Internet, etc., as described in more detail below).

[055] In some non-limiting embodiments of the present technology, the networked computing environment 200 may include a GPS satellite (not shown) transmitting a GPS signal to and/or receiving a GPS signal from the electronic device 210. It should be understood that the present technology is not limited to the GPS system and may use a location technology other than the GPS system. It should be noted that the GPS satellite may not be available at all.

[056] The vehicle 220 with which the electronic device 210 is associated can be any vehicle for recreation or other purposes, such as a car for personal or commercial use, a truck, a motorcycle, and so on. Although the vehicle 220 is depicted as a ground vehicle, this is not required for every non-limiting embodiment of the present technology. For example, in some non-limiting embodiments of the present technology, vehicle 220 may be a waterborne vehicle, such as a boat, or an aircraft, such as a drone.

[057] Vehicle 220 may be driven by a user or may be a self-driving vehicle. In some non-limiting embodiments of the present technology, it is contemplated that vehicle 220 may be implemented as a Self-Driving Car (SDC). It should be noted that no restrictions are imposed on specific parameters of the vehicle 200, such as vehicle manufacturer, vehicle model, vehicle year, vehicle weight, vehicle dimensions, vehicle weight distribution, vehicle surface area, vehicle height, transmission type (for example, two or four wheel drive), tire type, brake system, fuel system, mileage, vehicle identification number and engine displacement.

[058] According to the present technology, the implementation of the electronic device 210 is not subject to any specific restrictions. For example, the electronic device 210 may be implemented as a vehicle engine control unit, a vehicle central processing unit, a vehicle navigation device (eg, TomTom™, Garmin™), a tablet, a personal computer built into the vehicle 220, etc. . It should be noted that the electronic device 210 may or may not be associated with the vehicle 220 in a permanent manner. Additionally or alternatively, the electronic device 210 may be implemented as a wireless communication device such as a mobile phone (eg, smartphone or cordless phone). In some embodiments, the electronic device 210 includes a display 270.

[059] Electronic device 210 may include some or all of the elements of computer system 100 shown in FIG. 1, depending on the specific embodiment of the invention. In some embodiments, the electronic device 210 is an on-board computing device and includes a processor 110, a solid state drive 120, and a memory 130. In other words, the electronic device 210 includes hardware and/or software and/or firmware, or a combination thereof, for processing data, as described in more detail below.

[060] In some non-limiting embodiments of the present technology, communication network 240 is the Internet. In alternative non-limiting embodiments of the present technology, communications network 240 may be implemented as any suitable local area network (LAN, Local Area Network), wide area network (WAN, Wide Area Network), private communications network, and the like. It should be understood that the embodiments of the communications network 240 are for illustrative purposes only. Between the electronic device 210 and the communication network 240, a communication link (not separately indicated) is provided, the implementation of which depends, among other things, on the implementation of the electronic device 210. By way of non-limiting example only, in those embodiments of the present technology where the electronic device 210 is implemented as a wireless communication device such as a smartphone or navigation device, the communication link may be implemented as a wireless communication link. Examples of wireless links include a 3G network link, a 4G network link, and the like. Communication network 240 may also use a wireless connection to server 235.

[061] In some embodiments of the present technology, the server 235 is implemented as a computer server and may contain some or all of the elements of the computer system 100 shown in FIG. 1. In one non-limiting example, server 235 is implemented as a Dell™ PowerEdge™ server running the Microsoft™ Windows Server™ operating system, but it may also be implemented using any other suitable hardware, software, and/or firmware or a combination thereof. In the present non-limiting embodiments of the present technology, the server 235 is a single server. In other non-limiting embodiments of the present technology (not shown), the functions of the server 235 may be distributed among multiple servers.

[062] In some non-limiting embodiments of the present technology, the processor 110 of the electronic device 210 may be associated with the server 235 to receive one or more updates. Such updates may include, but are not limited to, software updates, map updates, route updates, weather updates, and the like. In some non-limiting embodiments of the present technology, processor 110 may also send some operational data, such as routes travelled, traffic data, performance data, and the like, to server 235. Some or all of the data transmitted between vehicle 220 and server 235 may be encrypted and/or anonymised.

[063] It should be noted that the electronic device 210 may use a variety of sensors and systems to collect information about the environment 250 of the vehicle 220. As shown in FIG. 2, vehicle 220 may be equipped with a plurality of sensor systems 280. It should be noted that various sensor systems from the plurality of sensor systems 280 may be used to collect various types of data about the environment 250 of the vehicle 220.

[064] In one example, the plurality of sensor systems 280 may comprise various optical systems, including, but not limited to, one or more camera-type sensor systems mounted on vehicle 220 and coupled to processor 110 of electronic device 210. In general, one or more camera-type sensor systems may collect image data about various parts of the environment 250 of the vehicle 220. In some cases, image data provided by one or more camera-type sensor systems may be used by the electronic device 210 to perform object detection procedures. . For example, the electronic device 210 may transmit image data provided by one or more camera-type sensor systems to an Object Detection Neural Network (ODNN) trained to locate and classify potential objects in the environment 250 of the vehicle 220.

[065] In another example, the plurality of sensor systems 280 may include one or more radar sensor systems mounted on vehicle 220 and coupled to processor 110. In general, one or more radar sensor systems may use radio waves to collect data about various parts of the environment 250 of the vehicle 220. For example, one or more radar sensor systems may collect radar data about potential objects in the environment 250 of the vehicle 220 and this data may relate to the distance from the radar sensor system to objects, to the orientation of objects, to the speed of objects, etc.

[066] It should be noted that the plurality of sensor systems 280 may include other types of sensor systems in addition to the examples described above, within the scope of the present technology.

[067] Lidar system

[068] In accordance with the present technology and as shown in FIG. 2, vehicle 220 is equipped with at least one laser detection and ranging system (lidar), such as lidar system 300 for collecting information about the environment 250 of vehicle 220. Although lidar system 300 is described here only as being attached to vehicle 220, it is also contemplated that it may operate autonomously or connected to another system.

[069] Depending on the embodiment of the invention, the vehicle 220 may contain more or less lidar systems 300 than shown in the figures. Depending on the specific embodiment of the invention, the decision on the number of specific sensor systems 280 from a plurality of such systems may depend on the specific embodiment of the lidar system 300. The lidar system 300 may be installed on the vehicle 220 initially or when it is upgraded in various locations and/ or in different versions.

[070] For example, depending on the implementation of the vehicle 220 and the lidar system 300, the lidar system 300 may be mounted on the inner top of the windshield of the vehicle 220. Here, as shown in FIG. 2, installation of the lidar system 300 in other locations, including the rear window, side windows, front hood, roof, front grille, front bumper, or side of the vehicle 220, is within the scope of the present technology. In some cases, the lidar system 300 may be mounted in a special case mounted on top of the vehicle 220.

[071] In some non-limiting embodiments of the invention, such as shown in FIG. 2, one lidar system 300 of a plurality of such systems is mounted on the roof of vehicle 220 and is rotatable. For example, lidar system 300 rotatably mounted on vehicle 220 may include at least some elements capable of rotating 360 degrees about the axis of rotation of lidar system 300. Lidar system 300 rotatably mounted may collect data about most of the surrounding space 250 of the vehicle 220.

[072] In other non-limiting embodiments of the present technology, such as shown in FIG. 2, the lidar system 300 is mounted on the side or on the front grille and is, for example, non-rotatable. In particular, the lidar system 300, mounted on the vehicle 220 without the ability to rotate, may contain at least some elements that are not able to rotate 360 degrees, but are able to collect data on specified parts of the environment 250 of the vehicle 220.

[073] Regardless of the particular location and/or particular implementation, the lidar system 300 is capable of collecting data about the environment 250 of the vehicle 220, for example, to build a multidimensional map of objects in the environment 250 of the vehicle 220. The following describes how the lidar system 300 collects data about the surrounding space 250 of the vehicle 220.

[074] In FIG. 3 is a diagram of one particular embodiment of lidar system 300 implemented in accordance with non-limiting embodiments of the present technology.

[075] In general, the lidar system 300 includes a variety of internal elements, including: (1) a light source 302 (also referred to as a radiation source), (2) a beam splitter 304, (3) a scanning unit 308 (also referred to as a scanning node) , (4) receiving unit 306 (also referred to as a detection system, receiving node, or detector), (5) controller 310. It is contemplated that, in addition to the internals listed above, lidar system 300 may include a plurality of sensors (such as, for example, temperature sensor, humidity sensor, etc.), which are not shown in FIG. 3 for simplicity.

[076] In some non-limiting embodiments of the present technology, one or more internal elements of the lidar system 300 may be implemented in a common housing 330, as shown in FIG. 3. In some embodiments of the present technology, the controller 310 may be located outside the common housing 330 and associated with the elements located therein.

[077] In general, the lidar system 300 operates as follows: the light source 302 of the lidar system 300 emits pulses of light to form an output beam 314, the scanning unit 308 scans the surrounding space 250 of the vehicle 220 with the output beam 314 to detect or obtain data about those in it. previously unknown objects (such as object 320), for example, to create a multidimensional map of the surrounding space 250, where objects (including object 320) are represented as one or more data points. Light source 302 and scanner 308 are described in more detail below.

[078] In some non-limiting examples, object 320 may include, in whole or in part, a person, vehicle, motorcycle, truck, train, bicycle, wheelchair, stroller, pedestrian, animal, road sign, traffic light, marking lanes, pavement markings, parking space, pylon, fence, road barrier, pothole, railroad crossing, obstacle on or near the road, curb, stopped vehicle on or near the road, pole, house, other structure, rubbish a tank, mailbox, tree, any other suitable object, or any suitable combination, in whole or in part, of two or more objects.

[079] Further, suppose an object 320 is located at some distance 318 from the lidar system 300. When the output beam 314 reaches the object 320, in general, the light of the output beam 314 may be at least partially reflected from the object 320, with some of the reflected light beams may be returned back to lidar system 300 as input beam 316. The term "reflection" means that at least a portion of the light from output beam 314 is reflected off object 320. Some of the light from output beam 314 may be absorbed or scattered by object 320.

[080] Thus, the input beam 316 is captured and detected by the lidar system 300 using the receiver unit 306. As a result, the receiver unit 306 is able to generate one or more representative data signals. For example, receiver 306 may generate an output electrical signal (not shown) that represents input beam 316. In addition, receiver 306 may transmit the thus generated electrical signal to controller 310 for further processing. Finally, by measuring the time between the moment the output beam 314 is emitted and the moment the input beam 316 is received, the controller 310 calculates the distance 318 to the object 320.

[081] As described in more detail below, beam splitter 304 directs output beam 314 from light source 302 to scanner 308 and input beam 316 from scanner to receiver 306.

[082] The use and implementation of these elements of the lidar system 300 in accordance with some non-limiting embodiments of the present technology are described below.

[083] Light Source

[084] The light source 302 is connected to the controller 310 and is capable of emitting light at a predetermined operating wavelength. To this end, in some non-limiting embodiments of the present technology, the light source 302 may comprise at least one laser tuned to operate at an operating wavelength. The operating wavelength of the light source 302 may be in the infrared, visible, and/or ultraviolet portion of the electromagnetic spectrum. For example, the light source 302 may include at least one laser with an operating wavelength in the range of approximately 650-1150 nm. Alternatively, the light source 302 may comprise a laser diode capable of emitting light in the wavelength range of about 800-1000 nm, about 850-950 nm, or about 1300-1600 nm.

[085] Typically, the light source 302 of the lidar system 300 is an eye-safe laser, or in other words, the lidar system 300 can be classified as an eye-safe laser system or laser product. In general, an eye-safe laser, laser system, or laser product can be a system with some or all of the following characteristics: emission wavelength, average power, peak power, peak intensity, pulse energy, beam size, beam divergence, exposure time, and characteristics output beam scanning, in which the probability of visual impairment of a person under the influence of the light emitted by this system is small or equal to zero.

[086] According to some non-limiting embodiments of the present technology, the operating wavelength of the light source 302 may lie in the region of the electromagnetic spectrum corresponding to the light emitted by the Sun. Therefore, in some cases, sunlight may act as background noise capable of masking the light signal detected by the lidar system 300. This solar background noise may lead to false positive detections and/or otherwise distort the measurements of the lidar system 300.

[087] In accordance with the present technology, the light source 302 includes a pulsed laser 388 capable of forming, emitting or emitting light pulses of a certain duration. For example, in some non-limiting embodiments of the present technology, the light source 302 may emit pulses with a duration (ie, pulse width) from 10 ps to 100 ns. In other non-limiting embodiments of the present technology, the light source 302 may emit pulses with a repetition rate of approximately 100 kHz to 5 MHz, or with a pulse repetition period (i.e., with a time interval between adjacent pulses) of approximately 200 ns to 10 μs. . However, in general, light source 302 may produce output beam 314 with any suitable average optical power, depending on the particular application.

[088] In some non-limiting embodiments of the present technology, the light source 302 may comprise one or more laser diodes, such as a Fabry-Perot laser diode, a quantum well laser, a distributed Bragg reflector (DBR) laser, a distributed feedback (DFB) or vertical cavity surface emitting laser (VCSEL), but not limited to. By way of example only, the laser diode in the light source 302 may be an aluminum gallium arsenide (AlGaAs) laser diode, an indium gallium arsenide (InGaAs) laser diode, an indium gallium arsenide phosphide (InGaAsP) laser diode, or any other suitable laser diode. It is also contemplated that the light source 302 may comprise one or more laser diodes modulated by current to generate optical pulses.

[089] According to the present technology, the light source 302 of the lidar system 300 further comprises an amplifier 390, specifically, in the example shown, a doped fiber amplifier 390, also shown in FIG. 3. The fiber amplifier 390 may be an erbium-doped fiber amplifier where erbium ions are introduced into the fiber core. The pulsed laser 388 is connected to the fiber amplifier 390 and the light pulses emitted by the pulsed laser 388 are received and amplified by the fiber amplifier 390.

[090] In some non-limiting embodiments of the present technology, the fiber amplifier 390 is an erbium-doped fiber amplifier 390, and in some cases, an erbium-doped fiber amplifier (EDFA) 390. For embodiments of the lidar system 300 implementing the EDFA amplifier 390, the pulses emitted by the pulsed laser 388 are amplified by excited erbium ions in the fiber core of the EDFA amplifier 390. pump or pump frequency to ensure maximum pulse amplification. The pump frequency is determined by the population inversion rate in the doped fiber amplifier 390. As described in more detail below, when the pulse frequency (i.e., the rate at which pulses are emitted) of the pulsed laser 388 exceeds the pump (population inversion) frequency, due to incomplete pumping of the erbium fiber amplifier 390, there is a decrease in the power of the pulses emitted by the light source 302.

[091] It should be noted that in accordance with the present technology, the pulse width is the time during which the laser emits, and usually does not change, although this may not apply to all embodiments of the invention. The present technology aims to control the pulse repetition rate (also called the emission frequency), which is determined by the time between emission of pulses (ie, inversely proportional to the time between pulses). According to at least some non-limiting embodiments of the present technology, the time between pulses can be from 100 ns to 2 μs. It should also be noted that the pulse rate and pulse duration are not necessarily correlated, except that the pulse duration must be less than the time interval between pulses when the individual pulses are generated by the light source 302.

[092] In some non-limiting embodiments of the present technology, light source 302 is typically capable of emitting output beam 314 as a collimated optical beam, but it is contemplated that the resulting beam may have any divergence suitable for a given application. In general, the divergence of output beam 314 is an angular measure of the increase in the transverse dimension of the beam (eg, its radius or diameter) as output beam 314 propagates from light source 302 or lidar system 300. In some non-limiting embodiments of the present technology, output beam 314 may have a substantially circular cross section.

[093] It is also contemplated that the output beam 314 emitted by the light source 302 may be unpolarized or randomly polarized, may not have a specific or constant polarization (eg, the polarization may change over time), or may have a specific polarization (eg, the output beam 314 may have linear, elliptical or circular polarization).

[094] In at least some non-limiting embodiments of the present technology, output beam 314 and input beam 316 may be substantially coaxial. In other words, output beam 314 and input beam 316 may at least partially overlap or share a common propagation axis, with input beam 316 and output beam 314 following essentially the same optical path (but in opposite directions). However, in other non-limiting embodiments of the present technology, output beam 314 and input beam 316 may not be coaxial or, in other words, may not overlap or share a common propagation axis within lidar system 300 without departing from the spirit and scope of the present technology.

[095] It should be noted that in at least some non-limiting embodiments of the present technology, the light source 302 can rotate, for example, 360 degrees or less about a rotation axis (not shown) of the lidar system 300 if the lidar system 300 has the ability to rotate. However, in other embodiments of the invention, the light source 302 may be stationary even when the lidar system 300 is rotatable without departing from the spirit and scope of the present technology.

[096] Beam splitter

[097] As shown in FIG. 3, a beam splitter 304 is further provided located in the housing 330. For example, as previously mentioned, the beam splitter 304 is capable of directing an output beam 314 from the light source 302 to the scanner 308. Beam splitter 304 is also capable of directing input beam 316 reflected from object 320 to receiver 306 for further processing by controller 310.

[098] However, in accordance with other non-limiting embodiments of the present technology, the beam splitter element 304 may split the output beam 314 into at least two components of lower intensity, including a scanning beam (not shown separately) for scanning the surroundings. space 250 of the lidar system 300, and a reference beam (not shown separately), which is then directed to the receiver unit 306.

[099] In other words, it can be said that in these embodiments of the invention, the beam splitter element 304 is able to divide the intensity (optical power) of the output beam 314 between the scanning beam and the reference beam. In some non-limiting embodiments of the present technology, the beam splitter element 304 may divide the intensity of the output beam 314 equally between the scanning beam and the reference beam. In other non-limiting embodiments of the present technology, the beam splitter element 304 may divide the intensity of the output beam 314 between the scanning beam and the reference beam at any given split ratio. For example, the beamsplitter element 304 may use up to 80% of the intensity of the output beam 314 to form the scanning beam, and use the remainder, up to 20% of the intensity of the output beam 314, to form the reference beam. In addition, in other non-limiting embodiments of the present technology, the beam splitter element 304 is capable of varying the split ratio (eg, from 1% to 95% of the intensity of the output beam 314) as the scanning beam is formed.

[0100] In addition, it should be noted that some (eg, up to 10%) of the intensity of the output beam 314 may be absorbed by the material of the beam splitter element 304, depending on its design.

[0101] Depending on the implementation of the lidar system 300, the beam splitter element 304 may be provided in various forms, including as a glass prism beam splitter, a semi-silvered mirror beam splitter, a dichroic mirror prism beam splitter, a fiber optic beam splitter. element, etc., but not limited to this.

[0102] Thus, in accordance with non-limiting embodiments of the present technology, an open list of adjustable parameters associated with the beam splitter element 304, based on its particular application, may contain, for example, an operating wavelength range that may vary from a finite number wavelengths to extended light spectrum (eg, 1200 to 1600 nm), input angle of incidence, presence or absence of polarization, etc.

[0103] In a specific non-limiting example, the beam splitter element 304 may be implemented as a fiber optic beam splitter manufactured by OZ Optics Ltd., 219 Westbrook Rd Ottawa, Ontario K0A 1L0 Canada (Canada). It should be understood that the beam splitter element 304 may be implemented in any other suitable equipment.

[0104] Internal Beam Paths

[0105] As shown schematically in FIG. 3, lidar system 300 has a plurality of internal beam paths 312 that carry output beam 314 (produced by light source 302) and input beam 316 (received from ambient space 250). In particular, the light propagates along the internal beam paths 312 as follows: light from the light source 302 passes through the beam splitter 304 to the scanner 308, and the scanner 308 in turn directs the output beam 314 outward into the surrounding space 250.

[0106] Similarly, input beam 316 follows a plurality of internal beam paths 312 to receiver unit 306. In particular, input beam 316 is directed by scan unit 308 to lidar system 300 through beam splitter 304 to receiver unit 306. In some embodiments, lidar system 300 may include beam paths that direct input beam 316 directly from ambient 250 to receiver unit 306 (without passing input beam 316 through scan unit 308).

[0107] It should be noted that in various non-limiting embodiments of the present technology, the plurality of internal beam paths 312 may comprise various optical elements. For example, lidar system 300 may include one or more optical elements capable of normalizing, shaping, filtering, modifying, redirecting output beam 314 and/or input beam 316. For example, lidar system 300 may include at least one of a number of lenses, mirrors, filters (e.g., band pass or interference filters), optical fibers, circulators, beam splitters, polarizers, polarizing beam splitters, wave plates (e.g., half-wave or quarter-wave plates), diffractive elements, microelectromechanical (MEM) elements, collimator elements, and holographic elements.

[0108] It is contemplated that in at least some non-limiting embodiments of the present technology, one and some other internal beam paths of the plurality of internal beam paths 312 may share at least some common optical elements, but not in all, without exception, embodiments of the present technology.

[0109] Scan unit

[0110] In general, the scanner 308 directs the output beam 314 in one or more directions into the surrounding space 250. The scanner 308 is connected to the controller 310. Thus, the controller 310 can control the scanner 308 to direct the output beam 314 from the source to the desired direction and/or in accordance with a given scan characteristic. In general, in the context of this description, a scan characteristic can be the pattern or path along which scan unit 308 directs output beam 314 during operation.

[0111] In some non-limiting embodiments of the present technology, controller 310 may act on scanner 308 to scan output beam 314 in multiple horizontal and/or vertical angular ranges. The total range of angles over which scan unit 308 directs output beam 314 is referred to here as the field of view (FoV, Field of View). It is contemplated that the particular structure, orientation, and/or angular ranges may depend on the particular implementation of the lidar system 300. Typically, the field of view contains a plurality of regions of interest (ROI, Region Of Interest), defined as part of the field of view, which, for example, may contain objects of interest objects. In some implementations, the scanner 308 may further examine a selected area of interest 325. The area of interest 325 of the lidar system 300 may be an area, volume, area, angular range, and/or portion(s) of the surrounding space 250 in which the lidar system 300 may scan. and/or collect data.

[0112] It should be noted that the location of the object 320 in the environment 250 of the vehicle 220 may overlap with the region of interest 325, be covered by the region of interest 325, or encompass, at least in part, the region of interest 325 of the lidar system 300.

[0113] It should also be noted that in accordance with some non-limiting embodiments of the present technology, the scanner 308 is able to scan the output beam 314 horizontally and/or vertically and, accordingly, the area of interest 325 of the lidar system 300 can be oriented in horizontal direction and vertical direction. For example, region of interest 325 may be defined by a 45° angle in the horizontal direction and a 45° angle in the vertical direction. In some embodiments, different scan axes may have different orientations.

[0114] In accordance with the present technology, in order to scan the region of interest 325 with the output beam 314, the scan unit 308 comprises a pair of mirrors (not shown separately), each of which is independently connected to a respective galvanometer (not shown separately) to control it. Accordingly, the controller 310 rotates each mirror of the pair of mirrors with an appropriate galvanometer around its associated one of the mutually perpendicular axes, scanning the region of interest 325 according to a predetermined scan characteristic.

[0115] In some non-limiting embodiments of the present technology, scan unit 308 may further comprise a plurality of other optical and/or mechanical elements to enable scanning with output beam 314. For example, scan unit 308 may include one or more mirrors, prisms, lenses, microelectromechanical elements, piezoelectric elements, optical fibers, beam splitters, diffractive elements, collimator elements, etc. It should be noted that the scanning unit 308 may also include one or more additional actuators (not shown separately) that drive at least some other optical elements, for example, for their rotation, tilt, rotation or angular movement around one or more axes. .

[0116] Thus, the lidar system 300 may use a predetermined scan characteristic to generate a point cloud that substantially overlaps the region of interest 325 of the lidar system 300. As described in more detail below, this point cloud of the lidar system 300 may be used to render a multidimensional map of objects in the surroundings. space 250 of the vehicle 220.

[0117] From the description below, it should be understood that in some non-limiting embodiments of the present technology, a predetermined scan characteristic of the region of interest 325 may be associated with an appropriate scan rate.

[0118] Receiving unit

[0119] According to some non-limiting embodiments of the present technology, the receiving unit 306 is connected to the controller 310 and can be implemented in a variety of ways. In accordance with the present technology, the receiving unit 306 includes a sensor 307, such as a photodetector, but may include a photodetector, an optical receiver, an optical sensor, a detector, an optical detector, optical fibers, and the like, but is not limited to them. As noted above, in some non-limiting embodiments of the present technology, the receiving unit 306 may receive or detect at least a portion of the input beam 316 and generate an electrical signal corresponding to the input beam 316. For example, if the input beam 316 is an optical pulse, the receiving block 306 may generate an electrical current or voltage pulse corresponding to the optical pulse detected by receiver 306.

[0120] It is contemplated that in various non-limiting embodiments of the present technology, the receiving unit 306 may be implemented using one or more Avalanche PhotoDiodes (APDs), one or more Single-Photon Avalanche Diodes (SPADs). ), one or more PN photodiodes (for example, a photodiode structure formed by a p-type semiconductor and an n-type semiconductor), one or more PIN photodiodes (for example, a photodiode structure formed by an undoped region of an intrinsic semiconductor located between the regions p -type and n-type), etc.

[0121] In some non-limiting embodiments of the invention, the receiving unit 306 may also include circuitry elements that perform amplification, sampling, signal filtering, waveform conversion, analog-to-digital conversion, time-to-digital conversion, pulse detection, threshold detection, rising edge detection, falling edge detection, etc. For example, receiver unit 306 may include electronics capable of converting a received photocurrent (eg, the current produced by an APD diode when receiving an optical signal) into a voltage signal. The receiving unit 306 may also include additional circuitry for generating an analog or digital output signal corresponding to one or more characteristics (eg, leading edge, trailing edge, amplitude, duration, etc.) of the received optical pulse.

[0122] Controller

[0123] Depending on the implementation, the controller 310 may include one or more processors, an Application-Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), and/or other suitable circuitry elements. . In addition, controller 310 may include non-volatile computer-readable memory for storing instructions executed by controller 310 as well as data that controller 310 may generate based on signals received from other internal elements of lidar system 300 and/or issued to other internal elements of lidar system 300. The memory may include volatile elements (eg, RAM) and/or non-volatile elements (eg, flash memory, hard drive). The controller 310 may generate data during operation and store it in memory. For example, the data generated by the controller 310 may be associated with data points in the point cloud of the lidar system 300.

[0124] It is contemplated that in at least some non-limiting embodiments of the present technology, the controller 310 may be implemented similarly to the electronic device 210 and/or computer system 100 without departing from the spirit and scope of the present technology. In addition to collecting data from the receiving unit 306, the controller 310 can also provide control signals to the light source 302 and the scanner unit 308 and receive diagnostic data from them.

[0125] As previously stated, controller 310 is connected to light source 302, scan unit 308, and receiver unit 306. In some non-limiting embodiments of the present technology, controller 310 may receive electrical trigger pulses from light source 302, where each electrical trigger pulse corresponds to the emission of an optical pulse by the light source 302 . The controller 310 may further issue commands, a control signal, and/or a trigger signal to the light source 302 indicating when the light source 302 should generate optical pulses, such as output beam 314.

[0126] By way of example only, the controller 310 may output an electrical trigger signal representing electrical pulses, with the light source 302 emitting an optical pulse represented by an optical beam 314 in response to each electrical pulse of the electrical trigger signal. It is also contemplated that the controller 310 may cause the light source 302 to control one or more characteristics of the output beam 314 produced by the light source 302, such as, but not limited to, frequency, period, duration, pulse energy, peak power, average power, and wavelength of the optical pulses. them.

[0127] According to the present technology, the controller 310 is able to determine the "time of flight" values of the optical pulse to determine the distance between the lidar system 300 and one or more objects in the region of interest, as described below. The time-of-flight is based on time information associated with (1) a first time when an optical pulse (e.g., output beam 314) was emitted by light source 302, and (2) a second time when a portion of the optical pulse (e.g., input beam 316) has been detected or received by receiver 306. In some non-limiting embodiments of the present technology, the first time may correspond to the time controller 310 generates an electrical pulse associated with the optical pulse, and the second time may correspond to the time controller 310 receives from the receiver. block 306 of the electrical signal generated by receiving part of the optical pulse from the input beam 316.

[0128] In other non-limiting embodiments of the present technology, where the beamsplitter element 304 may split the output beam 314 into a scanning beam (not shown) and a reference beam (not shown), the first time may be the time of reception from the receiver unit 306 of the first an electrical signal generated in response to receiving part of the reference beam. Accordingly, in these embodiments of the invention, the second point in time can be defined as the moment when the controller 310 receives from the receiving unit 306 the second electrical signal generated in response to receiving another part of the optical pulse from the input beam 316.

[0129] In accordance with the present technology, the controller 310 is able to determine, based on the first and second points in time, the time-of-flight values and/or the amount of phase shift for the radiated pulse of the output beam 314. The time-of-flight T value, in a certain sense, is the transit time "there and back" of the emitted pulse from lidar system 300 to object 320 and back to lidar system 300. Thus, controller 310 is able to roughly determine distance 318 by the following formula:

where D is the distance 318, T is the time of flight, c is the speed of light (approximately 3.0×10 ⁸ m/s).

[0130] As previously stated, the lidar system 300 may be used to determine the distance 318 to one or more other potential objects located in the surrounding space 250. By scanning the output beam 314 of the area of interest 325 of the lidar system 300 in accordance with a given scan characteristic, the controller 310 is capable of displaying the distance (similar to distance 318) to the respective data points in the area of interest 325 of the lidar system 300. As a result, the controller 310 can typically visualize these successive data points (eg, point clouds) as a multidimensional map. In some implementations, data associated with a particular time-of-flight and/or distance to an object may be displayed in a different information format.

[0131] For example, this multi-dimensional map may be used by the electronic device 210 to detect or otherwise identify objects, or to determine the shape or distance of potential objects in the area of interest 325 of the lidar system 300. It is contemplated that the lidar system 300 can repeatedly or iteratively acquire and/ or form point clouds at any rate suitable for the application.

[0132] System control method

[0133] Referring to FIG. 4 is a flow diagram of a method 400 for controlling lidar system 300 in accordance with non-limiting embodiments of the present technology.

[0134] In some non-limiting embodiments of the present technology, method 400 may be implemented by controller 310 connected to lidar system 300. As noted above, in at least some non-limiting embodiments of present technology, controller 310 may comprise one or multiple processors, and may be implemented similarly to electronic device 210 and/or computer system 100 without departing from the spirit and scope of the present technology. Implementation of method 400 begins at step 410.

[0135] Step 410: exercising the light source to emit light pulses at the first pulse rate.

[0136] In step 410, the controller 310 issues commands, a control signal and/or a trigger signal to the light source 302 indicating when the light source 302 should emit light pulses towards the scan unit 308 at a first pulse rate. As mentioned above, the pulse rate is the speed or frequency at which the pulses are emitted by the light source 302.

[0137] When method 400 begins, the first pulse rate is typically the same for different parts of the field of view and is less (slower) than the pump frequency of fiber amplifier 390. Thus, for each sample pulse, the desired maximum gain is provided at the output of fiber amplifier 390. In some Non-limiting embodiments of the method assume that samples from different parts of the field of view may arrive at different frequencies for reasons beyond the scope of the present technology. For ease of explanation, the description of method 400 herein assumes that no other methods of operation are used concurrently with it to control lidar system 300, although it is contemplated that present method 400 may be performed in addition to and/or concurrently with other methods of operation.

[0138] In one or more steps of method 400, controller 310 may cause light source 302 to start emitting output beam 314 toward scan unit 308 under certain conditions. Such conditions may include operation of vehicle 220 in a self-steering mode, driving vehicle 220 in motion regardless of the driving control mode, driving a stationary vehicle 220, control at the initial start of the vehicle 220, manual control of the vehicle 220 performed by the user ( not shown), etc., but not limited to.

[0139] Step 420: direction of light pulses from the system.

[0140] In step 420, the controller 310 issues commands, a control signal, and/or a trigger signal, on which the scanner 308 is to direct the light pulses of the output beam 314 outward from the lidar system 300. Depending on the particular embodiment of the invention, these pulses scan a portion or the entire field of view of the lidar system 300 to form three-dimensional maps of the surrounding space falling into the field of view.

[0141] Step 430: detection of a light signal reflected from at least one object in the field of view of the system.

[0142] In step 430, the reflected light from the field of view of the lidar system 300 is received by the sensor 307 of the receiving unit 306. The controller 310 then receives a signal and/or information corresponding to one or more reflected light signals received by the sensor 307. As described above, the input beam 316 enters the lidar system 300 from the field of view and is directed by the elements of the lidar system 300 to the sensor 307 and to the receiving unit 306.

[0143] In at least some non-limiting embodiments of the present technology, the reception at 430 may include detecting a plurality of light signals reflected from one or more areas of interest in the field of view.

[0144] Step 440: determining the signal-to-noise ratio of the reflected light signal.

[0145] In step 440, the controller 310 determines or calculates the signal-to-noise ratio of the reflected signal received by the sensor 307 of the receiver unit 306. The signal-to-noise ratio is calculated by dividing the previously determined signal power by the background noise power level. Depending on the embodiment of the invention, the background noise level can be determined in various ways. According to one non-limiting embodiment of the invention, the background noise level may be determined by receiving or measuring the signal strength from the sensor 307 at a time when the input beam 316 has not yet reached the sensor 307. In at least some non-limiting embodiments of the invention the background noise level can be determined by placing a shutter in front of the sensor 307 to periodically block the input beam 316 and measuring the sensor signal 307 while the shutter is blocking the input beam 316. Depending on the implementation of the method, the background noise level can be determined episodically or at a constant frequency.

[0146] In at least some non-limiting embodiments of the present technology, controller 310 may determine the signal-to-noise ratio of a portion of the reflected signal received by sensor 307 corresponding to a region of interest (ROI) in the field of view. Depending on an embodiment of the invention, individual signal-to-noise ratio values for one or more regions of interest may be determined by the controller 310 simultaneously and/or alternately. For example, different values of the signal-to-noise ratio for different parts of the field of view can be determined in one scan cycle. In another non-limiting example, the controller 310 may determine the signal-to-noise ratio for different portions of the field of view in different scan cycles of the field of view.

[0147] Step 450: determining the difference between the signal-to-noise ratio and the threshold signal-to-noise ratio.

[0148] At step 450, the controller 310 determines the difference between the signal-to-noise ratio and the threshold signal-to-noise ratio. Having determined the signal-to-noise ratio in step 440, the controller compares it to a threshold signal-to-noise ratio to determine the relative signal level of the input beam 316. In at least some non-limiting embodiments of the invention, determining this difference may include determining the absolute value and the sign of the difference between the signal-to-noise ratio and the threshold value. In at least some non-limiting embodiments of the invention, the fact that the signal-to-noise ratio exceeds a threshold value can be determined.

[0149] In at least some non-limiting embodiments of the invention, the threshold signal-to-noise ratio is generally the minimum allowable signal-to-noise ratio below which noise affects signal quality. In at least some non-limiting embodiments of the invention, the threshold signal-to-noise ratio may be the minimum acceptable value, however, at some lower values, such signal-to-noise ratio may still collect reliable data. In at least some non-limiting embodiments of the present technology, the threshold signal-to-noise ratio is a predetermined value stored in the controller 310, however, it can also be stored in the electronic device 210 and/or computer system 100 without derogation. from the essence and scope of this technology. It is also contemplated that this threshold may be calculated by controller 310 (or electronic device 210 and/or computer system 100) as a function of lidar system 300 variables, including environmental and/or weather conditions, daylight and artificial light levels, required range ( desired current range), current speed and road conditions, but not limited to.

[0150] Step 460: acting on the basis of said difference on the light source to emit light pulses at a second pulse rate different from the first pulse rate.

[0151] In step 460, the controller 310, based on said difference, causes the light source to emit light pulses at a second pulse rate different from the first pulse rate.

[0152] In at least some non-limiting embodiments of the present technology, controller 310 may cause light source 302 to change the pulse rate of output beam 314 at any non-zero difference between the signal-to-noise ratio determined in step 450 and the threshold. In at least some other non-limiting embodiments of the invention, the controller 310 may cause the light source 302 to change the pulse rate of the output beam 314 if the difference between the threshold value and the determined signal-to-noise ratio exceeds a minimum difference value. As one non-limiting example, the light source 302 may change the pulse rate if the determined signal-to-noise ratio is at least twice the signal-to-noise ratio threshold.

[0153] In one or more non-limiting steps of method 400, controller 310 may determine whether a signal-to-noise ratio value exceeds a threshold signal-to-noise ratio. In such a case, the pulse rate of the light source 302 may be increased such that the second pulse rate is greater (faster) than the first pulse rate. In at least some non-limiting embodiments of the present technology, the second pulse rate may be greater than the pump frequency of the light source 302, in particular the pump frequency of the fiber amplifier 390. As mentioned above, the power of the output beam 314 is typically reduced ("droop" ) in cases where the pulse repetition rate of the output beam 314 is greater than the pump frequency of the amplifier 390. If at step 450 it is determined that the signal-to-noise ratio exceeds the threshold value, then it is considered that when the power of the output beam 314 decreases, the signal-to-noise ratio should remain sufficiently high to form the required three-dimensional map. In other words, the pulse rate of the output beam 314 can be increased to create a more detailed 3D map while maintaining at least a minimum signal-to-noise ratio. Thus, the spatial resolution (determined by the pulse repetition rate) can be improved for the entire field of view or its part, in which the signal quality is high enough and some reduction is acceptable (to a level not lower than the minimum acceptable signal quality).

[0154] In at least some non-limiting embodiments of the present technology, method 400 further includes determining a second signal-to-noise ratio when light source 302 generates output beam 314 at a second pulse rate after previous signal-to-noise measurements. The methods for determining the second signal-to-noise ratio may be the same or different from those used to determine the initial signal-to-noise ratio, depending on the particular implementation.

[0155] In at least some such non-limiting embodiments of the invention, method 400 may further include determining by controller 310 that the second signal-to-noise ratio is less than a threshold signal-to-noise ratio. In this case, the controller 310 may cause the light source 302 to emit light pulses at a third pulse rate different from the second pulse rate. As one non-limiting example, the third pulse rate may be less than the second pulse rate, whereby the amplifier 390 will have more time to pump the amplifier 390 to increase the power of the output beam 314 and help restore the desired signal-to-noise ratio. In some cases, the third pulse repetition rate is equal to the first pulse repetition rate, i.e. output beam 314 is formed at the same pulse rate as originally. In some other non-limiting embodiments of the invention, it is contemplated that the third pulse rate may be greater than or less than the first frequency, depending on various factors in the lidar system 300 or a particular implementation thereof.

[0156] In at least some non-limiting embodiments of the present technology, determining the signal-to-noise ratio of the reflected light signal in step 440 includes determining, by the controller 310, signal-to-noise ratio values for one or more subzones (signal-to-noise ratio of subzones) , where the signal-to-noise ratio of the subzone corresponds to the signal-to-noise ratio of the part of the reflected signal coming from the area of interest within the field of view of the lidar system 300. In such an embodiment, the method 400 may include determining, in step 450, the difference between the signal-to-noise ratio one or more subzones and a threshold signal-to-noise ratio. In at least some such non-limiting embodiments of the invention, the controller 310 may determine that the signal-to-noise ratio for a certain subzone is greater than a threshold signal-to-noise ratio and cause the light source 302 to emit light pulses at a second scan pulse rate. region of interest, for which the signal-to-noise ratio of the subzone is determined. In some cases, the controller 310 may determine that the signal-to-noise ratio of the plurality of subzones exceeds a threshold and cause the light source 302 to emit light pulses at a second pulse rate while scanning the respective areas of interest. In at least some of these non-limiting embodiments of the invention, it is also contemplated that the controller 310 can act on the light source 302 to emit light pulses at different pulse rates while scanning different areas of interest, depending on the difference between the signal-to-noise ratio in each subzone and threshold value.

[0157] In at least some non-limiting embodiments of the present technology, the method 400 may further include operating the controller 310 on the light source 302 to return to a first pulse rate for one or more regions of interest, one or more subregions, and /or the entire field of view after a certain period of time. In at least some non-limiting embodiments of the present technology, the method 400 may further include exposing the light source 302 to return to the first pulse rate after determining the degradation of the 3D map according to methods outside the scope of the present technology.

[0158] It should be clear to those skilled in the art that at least some embodiments of the present technology are aimed at expanding the arsenal of technical means to solve a specific technical problem, namely, improving the quality of spatial localization of objects by a lidar system while limiting the influence of signal quality.

[0159] For a person skilled in the art, possible changes and improvements in the above-described embodiments of the present technology may be obvious. The foregoing description is for illustrative purposes only and is not intended to limit the scope of the invention. The scope of protection of this technology is determined solely by the scope of the appended claims.

[0160] While embodiments of the invention have been described above with specific steps performed in a specific order, it should be understood that some of these steps may be combined, subdivided, or reordered without departing from the spirit and scope of the present technology. Accordingly, the order of execution and grouping of these steps is not a limitation of the present technology.

Claims (54)

1. A method for controlling a laser detection and ranging system, including: - the impact of the controller on the light source to emit light pulses with a first pulse repetition rate; - the direction of the scanning unit connected to the controller, the pulses of light from the optical system; - detection by at least one sensor connected to the controller, a light signal reflected from at least one object in the field of view of the optical system; - determination by the controller of the signal-to-noise ratio of the reflected light signal; - determining by the controller the difference between the signal-to-noise ratio and the threshold signal-to-noise ratio, and the signal-to-noise ratio exceeds the threshold signal-to-noise ratio; causing the controller to act on the light source to emit light pulses at a second pulse rate different from the first pulse rate based on this difference, the second pulse rate being greater than the first pulse rate, and the second pulse repetition rate is greater than the pumping frequency of the light source. 2. The method of claim 1, wherein the signal-to-noise ratio is the first signal-to-noise ratio, and which further includes: - determination by the controller of the second signal-to-noise ratio after its impact on the light source to emit light pulses with a second pulse repetition rate; - determining by the controller that the second signal-to-noise ratio is less than the threshold signal-to-noise ratio; And - impact by the controller on the light source to emit light pulses with a third pulse repetition rate different from the second pulse repetition frequency. 3. The method of claim 2, wherein the third pulse rate is equal to the first pulse rate. 4. The method according to claim 1, in which determining the signal-to-noise ratio of the reflected light signal includes determining the signal-to-noise ratio of the subzone corresponding to the signal-to-noise ratio of the part of the reflected signal coming from the area of interest in the field of view, while: - determining the difference between the threshold signal-to-noise ratio and the signal-to-noise ratio includes determining by the controller that the signal-to-noise ratio of the subzone is greater than the threshold signal-to-noise ratio; And - the action by the controller on the light source to emit light pulses with a second pulse repetition rate includes the influence of the controller on the light source to emit light pulses with a second pulse repetition rate when scanning the area of interest, if the signal-to-noise ratio of the subzone exceeds the threshold signal-to-noise ratio. 5. The method according to claim 4, in which: - determining the signal-to-noise ratio of the subzone includes determining by the controller a plurality of signal-to-noise ratios of the subzone for the plurality of regions of interest; - determining that the signal-to-noise ratio of the subzone is greater than the threshold signal-to-noise ratio includes determining that at least one signal-to-noise ratio of the sub-zone from the plurality of signal-to-noise ratios of the sub-zone is greater than the threshold signal-to-noise ratio, while at least one subzone signal-to-noise ratio corresponds to signals received in the region of interest from the plurality of regions of interest; And - if at least one signal-to-noise ratio exceeds the threshold signal-to-noise ratio, the controller acts on the light source to emit light pulses with a second pulse repetition rate when scanning the region of interest. 6. A method for controlling a laser detection and ranging system, including: - the impact of the controller on the light source to emit light pulses with a first pulse repetition rate; - the direction of the scanning unit connected to the controller, the pulses of light from the optical system; - detection by at least one sensor connected to the controller, a plurality of light signals reflected in the field of view of the optical system, consisting of a plurality of areas of interest; - controlling the controller with a light source, at least in part, based on a plurality of reflected light signals, while the control for the area of interest includes: - determination by the controller of the signal-to-noise ratio of the reflected light signal of the region of interest; - determination by the controller of the difference between the signal-to-noise ratio and the threshold signal-to-noise ratio; And - the action of the controller on the light source to emit light pulses with a second pulse repetition rate different from the first pulse repetition frequency, based on this difference when scanning the area of interest, and the signal-to-noise ratio is greater than the threshold signal-to-noise ratio, and the second pulse repetition rate is greater than the first pulse repetition rate. 7. The method of claim 6, wherein the region of interest is the first region of interest, the signal to noise ratio is the first signal to noise ratio, and for the second region of interest, the method further includes: - determination by the controller of the second signal-to-noise ratio of the reflected light signal of the second region of interest; - determination by the controller of the difference between the signal-to-noise ratio and the threshold signal-to-noise ratio; And causing the controller to act on the light source to emit light pulses at a third pulse rate different from the first pulse rate based on this difference when scanning the second region of interest. 8. The method of claim 7, wherein the third pulse rate is equal to the second pulse rate. 9. Lidar system, containing: - Light source; - a scanning unit capable of directing light pulses from a light source; - a receiving unit capable of receiving light reflected from objects in the surrounding space, and containing at least one sensor; - a controller connected to at least the scanning unit and the receiving unit and capable of executing the commands stored therein, including: - the impact of the controller on the light source to emit light pulses with a first pulse repetition rate; - the direction of the scanning unit connected to the controller, the pulses of light from the optical system; - detection by at least one sensor connected to the controller, a light signal reflected from at least one object in the field of view of the optical system; - determination by the controller of the signal-to-noise ratio of the reflected light signal; - determination by the controller of the difference between the signal-to-noise ratio and the threshold signal-to-noise ratio; And - causing the controller to act on the light source to emit light pulses at a second pulse rate different from the first pulse rate based on this difference, wherein the second pulse repetition rate is greater than the first pulse repetition rate. 10. The system of claim 9, wherein the light source comprises a laser connected to a controller and a doped fiber amplifier. 11. The system of claim. 9, in which the second pulse repetition rate is greater than the first pulse repetition rate and greater than the pump frequency of the doped fiber amplifier. 12. Lidar system, containing: - Light source; - a scanning unit capable of directing light pulses from a light source; - a receiving unit capable of receiving light reflected from objects in the surrounding space and containing at least one sensor; And - a controller connected at least to the scanning unit and to the receiving unit and capable of performing the method according to claim 6.

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