Distributed Modular Solid-State LIDAR System

Abstract

The LIDAR system includes a first optical transmitter, the first optical transmitter including a plurality of first transmitters, wherein each of the plurality of first transmitters is positioned to generate a light beam having a FOV at a target range when excited. The second optical transmitter includes a plurality of second transmitters, wherein each of the plurality of second transmitters is positioned to generate a light beam having a FOV at a target range when excited. The first optical transmitter and the second optical transmitter are positioned relative to each other so that the FOVs of at least some of the light beams generated by the first optical transmitter and the second optical transmitter overlap at the target range when excited. The optical receiver includes a plurality of optical detectors, wherein a corresponding one of the plurality of optical detectors is positioned to detect a corresponding light beam generated by at least one of the first optical transmitter and the second optical transmitter and reflected by a target in the FOV at the target range. The controller includes a first output terminal and a second output terminal connected to the corresponding control input terminals of the first optical transmitter and the second optical transmitter, and a third output terminal connected to the control input terminal of the optical receiver. The controller generates a control signal at a first output terminal and a second output terminal, which controls the excitation of a selected emitter among the plurality of first emitters and the plurality of second emitters that generates a light beam having a FOV overlapping at a target range; and generates a control signal at a third output terminal, which activates a selected light detector among the plurality of light detectors to detect the light beam reflected from an object at the target range.

Description

[0001] The section headings used herein are for organizational purposes only and are not to be construed in any way as limiting the subject matter described in this application.

[0002] Related application section

[0003] This application is a non-provisional application of pending U.S. provisional patent application serial number 62 / 714,463, entitled “Distributed Modular Solid State LIDAR System,” filed on August 3, 2018. The entire contents of U.S. patent application serial number 62 / 714,463 are incorporated herein by reference. Background Art

[0004] Autonomous, self-driving and semi-autonomous cars use a combination of different sensors and technologies, such as radar, image recognition cameras and sonar, to detect and locate surrounding objects. These sensors enable many improvements to driver safety, including collision warnings, automatic emergency braking, lane departure warnings, lane keeping assist, adaptive cruise control and automatic (piloted) driving. Among these sensor technologies, light detection and ranging (LIDAR) systems play a vital role, enabling real-time, high-resolution 3D mapping of the surrounding environment.

[0005] Today, most commercially available LIDAR systems for autonomous vehicles utilize a small number of lasers combined with some method of mechanically scanning the environment. For example, several manufacturers provide rotating LIDAR systems with transmit / receive optics located on a spinning motor to provide a 360° horizontal field of view. A one-dimensional (1D) fixed laser array is used in the vertical direction, and horizontal scanning is accomplished by rotation. Currently, the largest 1D array on the commercial market contains 128 lasers. Some vendors use moving mirrors to scan the FOV. For example, MEMS or galvanometers can be used to actuate the mirrors. In these systems, only 1 or 2 lasers are usually used, combined with two mirrors, one for the horizontal direction and one for the vertical direction.

[0006] In mechanically scanned LIDAR systems, the scanning method imposes physical constraints on the receiver and transmitter optics. For example, in a rotary motor scanned LIDAR system, the receiver is typically placed on the same motor as the transmitter so that the transmitter and receiver "look at the same place" during operation. Similarly, the receiver in a scanning mirror device is typically positioned to use the same moving mirror as the transmitter so that light reflected from the target returns through the shared reflector optics and reaches the receiver. These physical constraints may limit the size of the LIDAR system(s) and the size and location of the individual components. In addition, these physical constraints can also affect performance characteristics such as measurement range and SNR / crosstalk. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] According to preferred embodiments and exemplary embodiments and further advantages thereof, the present teaching is described in more detail in the following detailed description in conjunction with the accompanying drawings. It will be appreciated by those skilled in the art that the drawings described below are for illustration purposes only. The drawings are not necessarily drawn to scale, but generally focus on illustrating the principles of the present teaching. These drawings are not intended to limit the scope of the applicant's teachings in any way.

[0008] Figure 1 The operation of a LIDAR system implemented in a vehicle is illustrated.

[0009] Figure 2 A distributed sensor system for an autonomous vehicle utilizing various types of known sensors is illustrated.

[0010] Figure 3 A schematic diagram representing a multi-sensor LIDAR system with multiple two-dimensional fields of view and ranges for an automobile is illustrated.

[0011] Figure 4 A schematic diagram of a known rotating LIDAR system for a vehicle is illustrated.

[0012] Figure 5 An autonomous vehicle is illustrated that is equipped with a number of known rotating LIDAR systems.

[0013] Figure 6 A known LIDAR system with multiple moving parts is illustrated.

[0014] Fig. 7A A schematic diagram of a solid-state LIDAR system is illustrated.

[0015] Figure 7B Pictured Fig. 7A Two-dimensional projection of the system field of view (FOV) of the LIDAR system.

[0016] Fig. 8AA measurement point cloud for a LIDAR system according to the present teachings is illustrated, wherein a single 2D laser array source illuminates the field of view.

[0017] Figure 8B A measurement point cloud for a LIDAR system according to the present teachings is illustrated, wherein two 2D laser array sources illuminate the field of view.

[0018] Fig. 9 A cross-sectional schematic diagram of the structure of a known bottom-emitting VCSEL laser that may be used in a LIDAR system of the present teachings is illustrated.

[0019] Fig.10 Illustrated is a schematic diagram of an embodiment of a 2D monolithic VCSEL array having 256 individual laser emitters in accordance with the present teachings.

[0020] Fig.11 A schematic diagram of an embodiment of a modular LIDAR system including separate transmit and receive modules according to the present teachings is illustrated.

[0021] Fig.12 The diagram shows Fig.11 Example of a composite FOV generated by a modular LIDAR system.

[0022] Fig.13 An autonomous vehicle integrated with an embodiment of the modular LIDAR system of the present teachings is illustrated.

[0023] Fig.14 A schematic diagram of an embodiment of a modular LIDAR system including a joint transmit / receive module according to the present teachings is illustrated.

[0024] Fig.15 The diagram shows Fig.14 Example of a composite field of view generated by a modular LIDAR system.

[0025] Fig.16 An embodiment of a modular LIDAR system integrated into an autonomous vehicle according to the present teachings is illustrated.

[0026] Fig.17 A schematic diagram of an embodiment of a modular LIDAR system of the present teachings having a co-located controller module is illustrated.

[0027] Fig.18 The diagram shows Fig.17 Example of a composite field of view generated by a modular LIDAR system.

[0028] Fig.19An embodiment of an operating scenario including a modular LIDAR system including two separate receivers and two separate transmitters according to the present teachings is illustrated.

[0029] Fig. 20 A block diagram of an embodiment of a controller of the present teachings is illustrated. DETAILED DESCRIPTION

[0030] This teaching will now be described in more detail with reference to the exemplary embodiments of this teaching as shown in the accompanying drawings. Although this teaching has been described in conjunction with various embodiments and examples, it is not intended that this teaching be limited to such embodiments. On the contrary, as will be appreciated by those skilled in the art, this teaching includes various substitutions, modifications and equivalents. Those of ordinary skill in the art who can obtain this teaching will recognize that additional embodiments, modifications and embodiments and other fields of use are within the scope of this disclosure as described herein.

[0031] References in the specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present teachings. The phrase "in one embodiment" appearing in various places in the specification does not necessarily all refer to the same embodiment.

[0032] It should be understood that the various steps of the method of this teaching can be performed in any order and / or simultaneously, as long as the teaching remains operable. In addition, it should be understood that the apparatus and method of this teaching can include any number or all of the described embodiments, as long as the teaching remains operable.

[0033] Known LIDAR systems with moving parts are problematic for many reasons, including being prone to reliability issues. One aspect of the present teachings is the recognition that a solid-state LIDAR system can be designed with fewer physical constraints that does not require moving parts to scan the field of view, thereby improving both performance and flexibility in the integration of the LIDAR system within an autonomous vehicle. Additionally, a solid-state system with substantially more lasers enables possible operating modes that are not possible with mechanical scanning, such as the ability to randomly scan the field of view without any mechanical constraints on the scanning pattern.

[0034] For many reasons, LIDAR systems typically require multiple separate units to support measurement requirements. These reasons include, for example, size constraints, installation constraints, measurement requirements, integration with other systems, and many other reasons. Thus, there is a need for a modular and easily distributed LIDAR system.

[0035] The present teachings relate to solid-state LIDAR systems with multiple lasers that contain no moving parts, where each laser can correspond to a single fixed projection angle. The use of solid-state lasers per se does not imply that there are no moving parts, as MEMS devices are often referred to as solid-state. However, MEMS devices in LIDAR systems often contain physical motion, which can affect reliability and device life. One feature of a LIDAR system according to the present teachings is that the modular distributed system design is compatible with all solid-state systems, including those using solid-state laser arrays and / or systems without MEMS devices. This includes systems without physical motion.

[0036] Figure 1 The operation of a LIDAR system implemented in a vehicle is illustrated. The LIDAR system 100 includes: a laser projector (also called an illuminator), which projects a light beam 102 generated by a light source to a target scene; a receiver, which receives light 104 reflected from an object (shown as a person 106) in the target scene. The LIDAR system typically also includes: a controller and / or a system processor, which calculates distance information about the object 106 from the reflected light; and an element that can scan or provide a specific pattern of light, which can be a static pattern across the desired range and field of view. The receiver, controller, and system processor are used to convert the received signal light into a measurement result representing a point-by-point 3D mapping of the surrounding environment that falls within the range and field of view of the LIDAR system. In various embodiments, depending on the specific application and desired performance, the controller can be a simple circuit or can be a more complex processor.

[0037] The laser source and beam projection system forming the illuminator and receiver can be located on the front side of the vehicle 108. The laser source and beam projection system can also be referred to as a transmitter. Person 106 and / or another object (such as a car or a light pole) will provide light reflected from the source back to the receiver. Then, the controller or processor determines the range or distance to the object. As known in the art, the LIDAR receiver calculates range information based on the flight time measurement results of the light pulses emitted from the light source. In addition, the position information about the reflective surface is determined based on the known information about the beam profile that illuminates the scene in the target plane associated with a specific range and based on the specific design of the source and projector system, thereby generating a complete X, Y, Z or three-dimensional picture of the scene. In other words, the point-by-point three-dimensional (3D) mapping of the surrounding environment represents a collection of measurement data, which indicates the position information of all surfaces of the receiver from the illumination reflected from the source to the field of view of the LIDAR system. In this way, a 3D representation of the object in the field of view of the LIDAR system is obtained. Point-by-point 3D data mapping can also be referred to as a measurement point cloud.

[0038] Figure 2A distributed sensor system 200 for an autonomous vehicle 202 is illustrated, which utilizes multiple types of known sensors 204, 206, 208, 210, 212, 214, 216, 218. Each sensor technology has advantages and disadvantages. A combination of measurements output from different sensors 204, 206, 208, 210, 212, 214, 216, 218 is used to generate a set of data from a scene. The data set from the distributed sensor system 200, including various measurements from the scene, is processed together, so that error-free, safe and reliable navigation can be achieved in all situations. The distributed sensor system 200 includes multiple cameras 204, 206, 208, multiple ultrasonic sensors 210, 212, multiple radars 214, 216, a rotating LIDAR system 218 and a controller 220. The autonomous car 202 uses cameras 204, 206, 208 that can distinguish colors. The cameras 204, 206, 208 may also be used to view traffic lights, turn signals, and other emitted light from the scene being measured. The cameras 204, 206, 208 may also be mounted at a small physical interval, and their images are combined to produce a stereo image. Ultrasonic sensors 210, 212 are used to detect the proximity of objects within a few meters of the car. Radars 214, 216 are used to detect moving objects at a distance. Generally speaking, radars 214, 216 do not operate at the high resolution of LIDAR systems 218. LIDAR systems 218 are used to generate high-resolution 3D point clouds of the environment in real time. Controller 220 is used to generate and process data sets provided by the measurement outputs from all the various sensors 204, 206, 208, 210, 212, 214, 216, 218. The controller may also be used to coordinate the operation of the various sensors 204, 206, 208, 210, 212, 214.

[0039] Figure 3 A schematic diagram showing a multi-sensor LIDAR system 300 with multiple two-dimensional fields of view and ranges for a car 302 is illustrated. The system includes multiple LIDAR modules. No modules are shown, only the resulting fields of view and ranges are shown. For example, an adaptive cruise control function may require a field of view and range 304 with a narrow field of view, but with a longer distance range requirement, compared to a system with a wider field of view and shorter range and side "surround" fields of view and ranges 306, 308. The composite field of view of the car is the combined field of view of all LIDAR modules positioned around the vehicle, which may differ in performance characteristics of some or all of the modules. In Figure 3In the illustrated system 300, five LIDAR modules (not shown) are used to create a composite field of view. A long-range forward-looking LIDAR system field of view and range 304 has a field of view that overlaps with a second LIDAR module, which has a field of view and range 310 that has a wider field of view, but a shorter range capability. There is also a rear-view module that has a field of view and range 312 of similar dimensions to the field of view and range 310 of the second LIDAR system.

[0040] Although the present teachings describe LIDAR systems in the context of automobiles in which LIDAR is widely used for autonomous driving, self-driving or driver-assisted vehicles, it should be understood that embodiments can be applicable to any type of vehicle. Other types of vehicles may include robots, tractors, trucks, airplanes, drones, boats, ships, etc. The present teachings are also applicable to various fixed applications. For example, in high-density metropolitan areas, LIDAR can be used to monitor vehicle and pedestrian traffic. It is expected that LIDAR systems will be deployed in many different applications, especially as the cost of LIDAR systems becomes lower and lower in the near future. Those skilled in the art will recognize that the present teachings are not limited to the types of target objects detected and ranged as described herein, but are more broadly applicable to any type of target.

[0041] Figure 4 A schematic diagram of a known rotating LIDAR system 400 for a vehicle is illustrated. The LIDAR system 400 uses a rotating motor to provide a 360° horizontal scan of the environment. The LIDAR system 400 has a base 402. For example, the base 402 can be fixed to a car (not shown). The top 404 of the LIDAR system rotates relative to the base and contains receiver optics and transmitter optics. The field of view of the transmitter and the field of view of the receiver overlap at a distance corresponding to the target image plane. The receiver and transmitter optics can be a 1D array of lasers and detectors that are fixed in such a way that the desired vertical field of view is covered. Arrays of 16, 32, 64, or even 128 lasers are sometimes used with rotating LIDAR systems such as Figure 4 The vertical angular resolution is fixed and is generally equal to the ratio of the vertical field of view to the number of lasers in the fixed array. The horizontal angular resolution is a function of the rotational speed and operating parameters of the system and may vary based on the application and desired performance.

[0042] Conceptually, a single rotating LIDAR system can provide a full 360° view, enabling the use of a single LIDAR system. However, in practice, multiple rotating LIDAR systems are used to segment the field of view around the vehicle. Figure 5 An autonomous vehicle equipped with a plurality of known rotating LIDAR systems 500 is illustrated. Figure 5 The system shown in includes multiple individual rotating LIDAR systems 502 mounted on a roof rack, each system configured to achieve a separate field of view of less than 180°. Some systems include more than twelve individual rotating LIDAR systems 502. Note that, in general, a major portion of each rotating LIDAR unit has a field of view that is blocked in a direction that minimizes optical crosstalk of the multiple rotating LIDAR units. When a rotating unit is pointed in a direction in which the field of view is blocked, that particular LIDAR unit does not generate useful data. In this regard, the use of a rotating LIDAR can result in a significant reduction in cost and efficiency relative to a LIDAR system that continuously operates with a field of view of less than 180°.

[0043] Figure 6 A known LIDAR system 600 with multiple moving parts is illustrated. The system 600 uses a first reflector 602 and a second reflector 604 mounted on an XY galvanometer 606 that scans the environment in the vertical and horizontal directions. Light from a laser transmitter 608, which typically includes one or two lasers, is reflected from the first reflector 602 onto the second reflector 604, and the combination of the two reflectors 602, 604 determines the projection angle. One or two lasers are typically used in these systems, rather than a larger laser array as in a rotating LIDAR system, because it is physically difficult to align multiple laser / receivers to a reflector system without significant optical loss and complexity. The transmitted light is reflected from a target at an image plane 610, and a receiver 612 is configured to have a field of view that overlaps with the target at the image plane 610, so that the receiver 612 captures the reflected light. The size and orientation of the reflectors impose various mechanical constraints on the design. For example, the size of the reflectors constrains the amount of reflected light that can be gathered, thereby acting as an effective maximum aperture. Mirror size also affects performance and creates a trade-off between power consumption, scan speed, and system performance.

[0044] Fig. 7AA schematic diagram of a solid-state LIDAR system is illustrated. Transmitter 702 includes multiple lasers that can be configured as an array. Each individual laser can be independently emitted, and the beam emitted by each laser corresponds to the 3D projection angle and only subtends a portion of the entire system field of view. Therefore, each laser emitter generates a beam when excited (emitted), which illuminates the corresponding field of view within the target range. The transmitter field of view is a combination of the transmitter fields of view of various excitations. Although some embodiments of the present teaching use laser emitters, it should be understood that other emitters, such as LEDs or other devices that generate beams when excited, can be used. In some embodiments of the LIDAR system of the present teaching, all beams from the lasers in the laser array share a transmitter optical device 704 to produce projected light (illumination) 706. Reflected light 708 from the target range 710 shares a receiver optical device 712. In this example, a car 714 is shown in the target range 710. An example of a transmitter is described in detail in U.S. Patent Publication No. 2017 / 0307736A1 assigned to the present assignee. The entire contents of U.S. Patent Publication No. 2017 / 0307736A1 are incorporated herein by reference.

[0045] Fig. 7A The LIDAR system 700 shown in FIG. 7 uses a detector array 716 that typically has a smaller number of individual detector elements than a transmitter array with individual lasers. These detectors can be individually controlled so that a single or a group of detectors are activated to detect light on a specific receiver field of view within the target range. The receiver field of view represents a composite of the activated detector fields of view. Activation can include, for example, a controllable shutter in front of the detector that only passes light from a specific field of view within the target range, or applying a bias to a specific detector or group of detectors.

[0046] Figure 7B The diagram shows the combination Fig. 7A A two-dimensional projection of the system field of view 750 of the depicted LIDAR system 700. A single detector field of view of the detector array is shown as a small square 752. Circles 754 represent illumination measurement points associated with individual lasers energized in the transmitter.

[0047] exist Figure 7B In , the ratio of the number of detectors (i.e., the number of small squares 752) to the number of lasers (i.e., the number of circles 754) in each array is 1 to 9. Figure 7B In the particular example shown in , the detector array is a 5×5 array. The cost of the detector array can be significantly reduced compared to prior art flash LIDAR systems with equivalent angular resolution because the number of detectors required can be significantly reduced. Fig. 7AThe measurement resolution of the system is not determined by the size of the detector elements, but by the number of lasers in the transmitter and the collimation of the individual laser beams. These parameters are converted in a known manner into the size of the circle 754 within the target range, and the relative sizes of the circle 754 and the square 752 representing the field of view of the detector elements.

[0048] Figure 7B Picture shows Fig. 7A Key aspects of a LIDAR system. Fig. 7A A single 3D measurement point in the entire field of view of the LIDAR system is highlighted by a hash mark in a specific square 756, where the measurement point is shown as a specific black circle 758 corresponding to a specific single laser in the laser array. Figure 7B 754 and 752. It can also be seen that the measurement point falls within a single detector, where the field of view of the single detector has been shown with a cross-hatched pattern for identification. The figure illustrates that the 3D resolution of the LIDAR system 700 is determined by the number of lasers, as each laser corresponds to a specific angular projection angle, which results in the size of the circle 754 at the target range and the relative sizes of the circle 754 and square 752 representing the field of view of the detector element.

[0049] A feature of the present teachings is that the LIDAR module is solid-state with no moving parts. The LIDAR module combines multiple lasers, each of which generates a beam with a fixed projection angle. The resulting composite field of view and angular resolution of a LIDAR system comprising one or more modules is determined by the arrangement of the optics, lasers, and modules. The lasers in each module are grouped into 2D arrays, which, when combined with corresponding optics, are positioned to provide both the desired module composite field of view and the desired module angular resolution. Each individual laser generates a beam corresponding to a single pointing angle. Angular resolution can be achieved by interleaving the fields of view of two or more 2D laser arrays. When two fields of view generated by two separate 2D laser arrays overlap spatially, a resulting composite field of view with better angular resolution will be generated.

[0050] The physical size of the LIDAR system is important for integration into an autonomous vehicle. While current state-of-the-art systems are often bulky and are often mounted on roof racks, the goal is to eventually integrate the LIDAR systems into the chassis so that they blend seamlessly with the exterior and have an aesthetically pleasing appearance. There are certain components, such as headlights, where synergies can be gained by co-packaging with part or all of the LIDAR system. One aspect of the LIDAR system described herein is that it can be broken down into small modular components to support future requirements for making the LIDAR visually unobtrusive.

[0051] Fig. 8A A measurement point cloud 800 of a single 2D laser array source used to illuminate a field of view is illustrated. Each measurement point 802 represents a measurement signal based on the light emitted by a particular laser element in the array. The distance 804 between the vertical spacing of the measurement points 802 determines the vertical angular resolution. The horizontal spacing 806 of the points 802 on the point cloud determines the horizontal angular resolution of the point cloud 800.

[0052] Figure 8B A measurement point cloud 850 of an embodiment of the present teachings is illustrated, wherein the illumination of the second 2D laser array has been projected to substantially overlap with the first 2D laser array. Measurement points 852 corresponding to the first 2D VCSEL array are shown as circles, and measurement points 854 from the second 2D VCSEL array are shown as triangles. The composite point cloud 850 is formed by interleaving the fields of view of the two separate 2D arrays to achieve better angular resolution in the horizontal, vertical, or a combination of horizontal and vertical directions. An example of such a transmitter is described in U.S. patent application serial No. 62 / 538,149, entitled "VCSEL Array LIDAR With Small Angular Divergence," which has been assigned to the present assignee. The entire contents of U.S. patent application 62 / 538,149 are incorporated herein by reference.

[0053] Since each laser corresponds to a specific projection angle, the LIDAR system of the present teachings can utilize substantially more lasers than the mechanical scanning LIDAR systems of the prior art. For example, if an autonomous vehicle requires a full 360° horizontal field of view, with a uniform vertical field of view of 20°, and an average angular resolution of 0.5° in both directions, then the number of lasers required is equal to 28,800. For LIDAR systems that require thousands of individual lasers, not all types of lasers can be implemented in a practical manner. In fact, due to their current size, cost, and performance capabilities, various embodiments of the LIDAR systems of the present teachings that require a large number of lasers will likely use 2D arrays of vertical cavity surface emitting lasers (VCSELs). However, other types of transmitter arrays may also be used. Those skilled in the art will recognize that, in accordance with the present teachings, multiple types of lasers may be used in a LIDAR system.

[0054] One feature of the present teaching is that it can use various known VCSEL devices, including top emitting VCSELs, bottom emitting VCSELs, and various types of high power VCSELs. Fig. 9A schematic diagram of a cross section of the structure of a known bottom-emitting VCSEL laser 900 that can be used in the LIDAR system of the present teaching is illustrated. The area of ​​the emission aperture 902 of the VCSEL laser 900 typically ranges from a few microns in diameter (for mW power operation) to 100 microns in diameter or more (for CW power operation of 100 mW and greater). The VCSEL 900 is fabricated on a substrate 904, which can be, for example, GaAs or many other semiconductor materials. An N-type distributed Bragg reflector (DBR) layer 906 is positioned on the substrate. An active region 908 is constructed on the n-type DBR layer 906, followed by holes that can be formed in an oxide material. A p-type distributed Bragg grating DBR layer 912 is then grown on the active region. Typically, the p-type DBR is highly reflective, and the n-type DBR is partially reflective, resulting in light output 914 from the bottom, substrate side of the layer structure. The active region 908, oxide hole 910, and p-type DBR layer 912 are formed in a mesa structure. Top contact 916 and bottom contact 918 are used to provide current to the active region to generate output light. The oxide hole 910 confines the current to the active region 908. The top contact 916 is p-type and the bottom contact 918 is n-type. The emission hole 902 is formed in the bottom contact 918 to allow the output light 914 to be emitted from the bottom substrate side of the bottom emitting VCSEL. Note that in Fig. 9 Only one transmitting hole 902 is shown. Fig. 9 One element of a multi-element array is illustrated. This type of VCSEL 900 can be a single element, or a multi-element VCSEL that can be fabricated as a one-dimensional or two-dimensional array on a substrate 904.

[0055] In some embodiments, the VCSEL array is monolithic and the lasers all share the same substrate. A variety of common substrate types can be used. For example, the common substrate can be a semiconductor material. The common substrate can also include ceramic materials. In some embodiments, a 2D VCSEL array is assembled from a group of 1D laser bars.

[0056] In some embodiments, the VCSEL is a top-emitting VCSEL. In other embodiments, the VCSEL is a bottom-emitting VCSEL. A single VCSELS may have a single large emission aperture, or a single VCSELS may be formed of two or more sub-apertures within a larger effective emission diameter. A group of sub-apertures forming a larger effective emission area is sometimes referred to as a cluster. When one or more electrical drive signals are supplied to the contacts, the contacts on the VCSEL may connect the drive signals to one or more individual elements or a subset of all elements or elements to provide a variety of different lighting modes.

[0057] Fig.10A schematic diagram of an embodiment of a 2D monolithic VCSEL array 1000 with 256 individual laser emitters 1002 in accordance with the present teachings is illustrated. Each laser emitter 1002 has an emission aperture 1004 of diameter "a". The emission from each individual laser emitter 1002 substantially fills the entire emission aperture. Thus, each laser emitter 1002 generates a laser beam having an initial diameter "a" that is equal to the diameter 1004 of the emission aperture. The laser emitters 1002 are uniformly spaced apart in the horizontal direction at a spacing dx 1006. The laser emitters are uniformly spaced apart in the vertical direction at a spacing dy 1008. The overall size of the array measured from the center of the outermost laser is the distance Dx 1010 in the horizontal direction and the distance Dy 1012 in the vertical direction. The actual chip size will be slightly larger in dimension than the distance Dx 1010 and the distance Dy 1012. In various embodiments, the emitter 1002 can generate beams having various shapes other than a circular emitter shape. For example, ellipses, squares, rectangles, and various odd shapes can be implemented in various embodiments. In embodiments where the lasers are arranged in a 2D array, the rows and columns of lasers can be electrically driven in a matrix-addressable manner.

[0058] Some embodiments of the present teachings utilize bottom emitting high power arrays of VCSELs with a single large aperture per laser, such as Fig. 9 Other embodiments of the present teachings utilize top-emitting or bottom-emitting high power arrays of VCSELs where the total emitting area includes the sub-apertures. However, those skilled in the art will recognize that the present teachings are not limited to any single configuration of top and bottom emitting VCSELs and associated emitting apertures.

[0059] The use of 2D VCSEL arrays as building blocks for the LIDAR systems described herein establishes a platform that allows the physical size of the transmitter to be small. A typical 2D array with 256 high-power individual lasers can be implemented on a monolithic chip of approximately 4 mm x 4 mm. The laser 2D array is then used with selected optics to keep the physical dimensions as small as possible, such as by using microlens arrays, shared lenses with dimensions less than 20 mm, or diffractive optics with a maximum dimension of 20 mm, as examples.

[0060] Fig.11A schematic diagram of an embodiment of a modular LIDAR system 1100 according to the present teachings is illustrated, each module of the system including a single transmitter and a single receiver. The transmitter, receiver, and controller are physically separate modules 1102, 1104, 1106, 1108. There are two transmitter modules 1102, 1104, a receiver module 1106, and a controller module 1108. There is a connection 1110 for supplying power between the modules 1102, 1104, 1106, 1108, and there is communication between the controller module 1108 and the other modules 1102, 1104, 1106. The communication between the modules 1102, 1104, 1106, 1108 can be performed optically or electrically, and they can use various communication protocols, including Ethernet or other various other communication protocols. The power of the transmitter and receiver modules 1102, 1104, 1106 can be supplied by the controller module 1108 as shown in the figure, or it can be supplied separately. The modular LIDAR system 1100 is a relatively simple configuration, including only two transmitter modules 1102, 1104 and a single receiver module 1106. In other embodiments, a single controller module 1108 is used to control one or more transmitters and / or one or more receivers.

[0061] Fig.12 The diagram shows the combination of Fig.11 An example embodiment of a composite field of view 1200 generated by a modular LIDAR system 1100 is described. Fig.11 and Fig.12 , there is an area representing the field of view 1202 of one transmitter module 1102 and an area representing the field of view 1204 of another transmitter module 1104. As previously described, each transmitter module 1102, 1104 uses at least two 2D laser arrays that substantially overlap in the field of view to produce better angle measurement resolution. Circles 1206 illustrate the field of view of each laser element from the first array. Squares 1208 illustrate the field of view of each laser element from the second array. As shown in the figure, there are two 16X16 arrays of 256 lasers in each transmitter module 1102, 1104. They produce substantially overlapping fields of view shown by the corresponding close-packed arrays of circles 1206 and squares 1208. In this embodiment, the dual array configuration of the two modules 1102, 1104 is the same. Moreover, the fields of view 1202, 1204 for the corresponding transmitters are configured to be located side by side within the target range.

[0062] The total composite field of view of the two transmitters consists of 1,024 laser fields of view. In some embodiments, the emission wavelengths of the laser arrays in the first transmitter module 1102 and the second transmitter module 1104 are different. Moreover, in some embodiments, the laser wavelengths within a single transmitter module 1102, 1104 are different. For example, each laser array can emit a different wavelength. In this configuration, the wavelength of the laser field of view represented by the circle 1206 can be different from the wavelength of the laser field of view represented by the square 1208. In general, there is no limit to the number and distribution of wavelengths within an array or module. The number and location of different laser wavelengths are selected based on the desired effect on the field of view of the measurement target range. For the composite field of view 1200, the dashed box 1210 shows the field of view of a single receiver module, which is slightly larger than the field of view of the combined transmitter field of view 1202, 1204. In some embodiments, the receiver field of view 1210 includes multiple detector fields of view from multiple detectors configured as an array. It is generally desirable that the receiver field of view 1210 is slightly larger than the transmitter field of view 1202, 1204 to simplify alignment of the receiver field of view and the transmitter field of view.

[0063] The controller module 1108 manages the operation of the two transmitter modules 1102, 1104 to minimize optical crosstalk and optical power levels for eye-safe operation. The controller module 1108 also manages the receiver module 1106, which in some embodiments uses at least one 2D array of detectors, and in other embodiments, uses multiple 2D arrays of detectors. The number and location of the various detector arrays are selected to achieve a specific receive field of view within the target range. For example, if two wavelengths are used, the receiver can have two separate 2D arrays of detectors, one for each wavelength.

[0064] In general, the transmitter module of the present teachings includes a plurality of laser emitters. Each laser emitter is positioned to illuminate a specific transmitter field of view within a target range. In various embodiments, the plurality of emitters are positioned in various patterns. For example, the plurality of emitters can be a one-dimensional and / or two-dimensional array with specific spacing between emitters in the vertical and / or horizontal directions. The center of the present invention is the fact that individual and / or groups of emitters are positioned to illuminate a specific transmitter field of view within a target range. This information is typically known to the controller and is used to produce illumination in a specific field of view within the target range by controlling the excitation of individual and / or groups of emitters. The field of view of one or more transmitter fields of view that are illuminated at any particular time based on a signal from the controller contained in a particular transmitter is referred to as the transmitter field of view.

[0065] In general, the receiver module of the present teaching includes a plurality of detector elements. Each detector element is positioned to detect light from a specific detector field of view within the target range. In various embodiments, multiple detectors are positioned in various patterns. For example, multiple detectors can be one-dimensional and / or two-dimensional arrays with specific intervals between detectors in the vertical and / or horizontal directions. One aspect of the present teaching is the fact that individual and / or grouped detectors can be positioned to detect light from a specific detection field of view within the target range. The controller can know the field of view information, and by controlling the detector / receiver so that the selected detector is activated to detect light reflected from the target range in the field of view of the activated one or more detectors, the field of view information can be used to detect illumination from a specific field of view within the target range. The field of view of one or more detector fields of view that are activated at any particular time in a specific receiver to detect based on a signal from the controller is called the receiver field of view.

[0066] The controller may control the activation of specific detectors by any of a number of known control mechanisms. For example, a controllable aperture may be used to control the activation of one or more detector fields in the receiver field of view. Individual detector biases may also be controlled to control the activation of individual detector fields within the receiver field of view.

[0067] The overlapping areas between different transmitters and / or different receivers are often designed into the system to provide continuous tracking of an object across a particular composite field of view. For example, a continuous composite field of view is provided by two transmitters when at least some of the fields of view of the transmitters of each transmitter overlap to some extent. In addition, a continuous transmit-receive composite field of view is provided when at least one detector field of view overlaps with the overlapping transmitter field of view. The overlap of at least some of the individual detector fields of view from two receivers is also used to provide a continuous composite receive field of view across two different receivers.

[0068] In the overlapping region, the controller is used to achieve the performance goals of the system. For example, the controller can control the excitation of selected transmitters that generate light beams with overlapping fields of view at the target range so that only one transmitter in each of the two overlapping transmitters will generate a light beam that is detected by one of the light detectors during a specific light detection and ranging measurement when reflected from an object at the target range. This eliminates or significantly reduces crosstalk, especially for those transmitters operating at the same wavelength.

[0069] A feature of the present teachings is that control of emitters and detectors can be used to support the performance of modular LIDAR systems. The controller has information about the various FOV locations, as well as the ability to control the energization of individual and grouped laser emitters and control the excitation of individual detectors. The knowledge can be extended beyond the individual transmitters and / or receivers to include all connected modules. Thus, the controller is able to provide a specific transmitter field of view and a specific receiver field of view for any desired measurement sequence from all connected transmit, receive and / or transmit / receive modules at any specific time and / or within a target range. If different wavelengths are used within a single transmitter or across multiple transmitters, the details of the transmission and detection of multiple wavelengths are typically known and are also actively managed by the controller.

[0070] In some embodiments of the LIDAR system of the present teachings, the receivers can detect different wavelengths separately. In these embodiments, the laser transmitters can be excited simultaneously in overlapping fields of view, allowing simultaneous measurements and improving angular resolution, such as in combination with Figure 8B as described. One aspect of the present teachings is the recognition that configuring a LIDAR system with a controller having the ability to control the excitation of specific emitters and the activation of specific detectors provides the designer with control over many important performance parameters of the system. For example, the controller can be configured to control the excitation of the transmitters so that the illumination within the target range does not exceed the eye-safe maximum permissible exposure (MPE) limit for optical power at a specific aperture size. For example, if two or more emitter fields of view overlap such that the sum of the optical power within the aperture defined by the eye safety standard is too high, then the maximum permissible exposure may be exceeded.

[0071] The controller may also be configured to control the transmitter emitters and receiver detectors so that a one-to-one correspondence is maintained between the excited transmitters and the detectors configured to detect. The controller may control the transmitter emitters and receiver detectors so that a one-to-one correspondence is maintained between the transmitter field of view of the excitation from a set of transmitters and the receiver field of view from a set of detectors configured to detect. The controller may also be configured to control the excitation of the transmitters and / or the detection of the detectors to improve various performance metrics, such as reducing measurement crosstalk. For example, when the field of view of more than one transmitter overlaps with the detector and / or receiver field of view, measurement crosstalk is generated. These overlapping areas are usually designed into the system to provide continuous tracking of objects across a composite field of view. That is, a continuous composite field of view is provided by two transmitters when at least some of the fields of view of the transmitters of each transmitter overlap to some extent. In addition, at least one detector field of view overlaps with the transmitter field of view. In general, the overlap of at least some of the individual detector fields of view from two receivers is also used to provide a continuous composite field of view across two different receivers.

[0072] In addition, the controller can be configured to control the excitation of the transmitter and / or the activation of the detector to produce a desired and / or varying angular resolution at the target range. The controller can also be configured to control the excitation of the transmitter and / or the activation of the detector to track the object across a composite field of view. The composite field of view can be provided by one or more transmitters, one or more receivers, and / or one or more modules forming a modular LIDAR system.

[0073] One feature of the modular approach to LIDAR system design according to the present teachings is the ability to easily integrate the various modules into an autonomous vehicle. Fig.13 An autonomous car integrated with an embodiment of a modular LIDAR system 1300 according to the present teachings is illustrated. Three receiver modules 1302, 1304, 1306 are depicted near the roof of the car 1306. Eight transmitter modules 1310, 1312, 1314, 1316, 1318, 1320, 1322, 1324 are shown, located in various areas such as the rearview mirrors, headlights, and grills of the car 1308. Controller modules 1326 are respectively located in the trunk area of ​​the car 1308. The ability to have multiple modules of relatively small size allows the transmitters and receivers to be positioned in almost any location of the car 1308, which allows for seamless integration into the vehicle. The controller module 1326 is used to coordinate the operation of the various receiver modules 1302, 1304, 1306 and transmitter modules 1310, 1312, 1314, 1316, 1318, 1320, 1322, 1324 to minimize optical crosstalk and control eye safety.

[0074] The use of a single controller module 1326 also allows for smooth tracking of objects in front of the vehicle because, utilizing a solid-state system, the system can control the laser excitation patterns of the elements in the laser array within the various transmitter modules 1310, 1312, 1314, 1316, 1318, 1320, 1322, 1324 to continuously measure the object of interest. As an object crosses the boundary from one transmitter field of view to the next, the controller module 1326 can coordinate the transmitter modules 1310, 1312, 1314, 1316, 1318, 1320, 1322, 1324 and the receiver modules 1302, 1304, 1306 to prevent any gaps in the measurements. The modular design described herein is also easier to integrate into different types of vehicles due to the relatively small physical size. Known LIDAR systems that have larger single units and take up more space may have to be located outside the vehicle, such as in conjunction with Figure 5 As shown in the system described. Obviously, combined with Figure 5The described car would be aesthetically unappealing due to the need for a large roof rack with a mechanically rotating LIDAR and would have an undesirable aerodynamic structure that would affect the efficiency of the car.

[0075] One feature of the modular LIDAR system of the present teachings is the ability to minimize electrical crosstalk between transmitter and receiver elements. Typically, lasers used for automotive LIDAR have relatively high power, operate under the premise of eye safety, and generally require large electrical drive pulse currents to generate light pulses. If the electrical signal from the transmitter is allowed to electromagnetically couple to the receiving circuit, excessive noise will be generated, which may provide erroneous return signals. This is a particularly difficult problem in the case where the LIDAR system has the ability to excite more than one laser pulse using different wavelengths. In these system configurations, the excitation time of any particular transmitting laser can be completely independent of the receiver timing. The modular LIDAR system of the present teachings can separate the transmit and receive signals to greatly reduce any electrical crosstalk problems. This separation can also be used to improve EMI emissions.

[0076] Fig.14 A schematic diagram of an embodiment of a modular LIDAR system 1400 is shown, wherein each module of the system includes multiple transmitters according to the present teachings. Fig.14 1404 and 1410. In the embodiment of the present invention, one modular unit 1402, 1404 contains several transmitters 1406 and a single receiver 1408. The controller module 1410 is a separate module. There is a connection between the modules using cables 1412 to supply power and communicate. The communication between the modules 1402, 1404, 1410 can be performed optically or electrically and in various communication protocols including Ethernet or other communication protocols. Power can be supplied to the transmit / receive modules through the controller module 1410 shown or separately.

[0077] Fig.15 The diagram shows Fig.14 An embodiment of a composite field of view 1500 generated by a modular LIDAR system 1400. Fig.14 and 15 , there is a field of view 1502 generated for the transmit / receive module 1402 and a field of view 1504 generated for the transmit / receive module 1404. Each of these fields of view 1502, 1504 includes a transmit field of view 1506, 1508, 1510, 1512 for each of the two transmitters in each module 1402, 1404, and a receive field of view 1514, 1516 for each receiver in each module 1402, 1404. The transmit / receive field of view 1502, 1504 of each module 1402, 1404 is nominally the same as Fig.12, and includes substantially overlapping fields of view for each of the 1,024 lasers. Thus, the composite field of view has the field of view for each of the 2,048 lasers. The fields of view 1500 of the two modules 1402, 1404 have been arranged to provide a total field of view that is exactly twice as large in the horizontal direction as a single unit. In various embodiments, the wavelengths of the two transmit / receive modules may be the same or may be different. Those skilled in the art will recognize that the present teachings are not limited by the number of wavelengths employed by the system. The controller module 1410 both operates the transmit-receive modules 1402, 1404 and serves to minimize optical crosstalk between modules and also maintain eye safety by controlling the laser drive excitation pattern for the transmit array.

[0078] One feature of the modular LIDAR system of the present teachings is that the composite field of view is designed to allow continuous tracking of objects across the field of view. Fig.15 The advantage of continuous tracking in the composite field of view 1500 described is that there are no gaps between the transmit fields of view 1506, 1508, 1510, 1512. However, there is an overlap in the receive fields of view 1514, 1516. This creates an overlap region 1518 in which both receive fields of view 1514, 1516 can detect light from both transmit fields of view 1508, 1510. The controller module 1410 is used to manage the excitation of specific lasers in the transmit array that generate light in the overlap region 1518 so that only minimal crosstalk exists. Therefore, in the receive field of view 1514, the lasing generated in the transmit field of view 1510 is minimized. Moreover, the lasing from the transmit field of view 1508 is minimized in the receive field of view 1516. In addition, the controller module 1410 manages the excitation of specific lasers in the transmitter array so that the peak power within the composite field of view 1500 never exceeds the eye-safe threshold power. In addition, the controller controls the excitation of a specific laser in the transmitter array that generates a light beam having an overlapping area 1518 at the target range so that only one of the first transmitter in the transmit / receive module 1402 and the second transmitter in the transmit / receive module 1404 generates a light beam that is detected by only one of the multiple light detectors in one of the first and second transmit / receive modules 1402, 1404 when reflected from an object at the target range during a specific light detection and ranging measurement.

[0079] Fig.16 An embodiment of a modular LIDAR system 1600 integrated into an autonomous vehicle 1602 in accordance with the present teachings is illustrated. Fig.16It is shown how modular transmit / receive modules 1604, 1606, 1608 are positioned on a car 1602. Two transmit / receive modules 1604, 1606 are placed near the roof 1610, while a single module 1606 is placed in a guardrail 1612 of the car 1602. A controller module 1614 is in the trunk of the car 1602. This arrangement can be more easily integrated into a variety of vehicles than known large mechanical rotating LIDAR systems.

[0080] A feature of the present teaching is that the sending, receiving and / or sending / receiving modules do not have to be packaged separately from the controller module. Thus, the sending, receiving and / or sending / receiving modules and the controller module do not have to be located in physically different locations. Fig.17 A schematic diagram of an embodiment of a modular LIDAR system 1700 of the present teachings having a co-located controller module 1702 is illustrated. A single housing 1704 is used to group together a set of transmit / receive modules 1706, 1708, 1710, 1712, 1714, 1716 with a single controller module 1702. For example, in the case of a large vehicle such as a semi-trailer or garbage truck, it may be desirable to use a modular system having a single common housing 1704. Such a common housing 1704 may provide additional ruggedness for environmental factors.

[0081] Fig.18 The diagram shows Fig.17 An embodiment of a composite field of view 1800 generated by a modular LIDAR system 1700. Fig.17 and Fig.18 , each transmit / receive module 1706, 1708, 1710, 1712, 1714, 1716 has a corresponding receive field of view 1802, 1804, 1806, 1808, 1810, 1812 and two corresponding transmit fields of view 1814, 1816, 1818, 1820, 1822, 1824, 1826, 1828, 1830, 1832, 1834, 1836. The transmit / receive modules 1706, 1708, 1710, 1712, 1714, 1716 use twenty-four 2D laser arrays with 256 lasers each. Fig.18It is illustrated that there are multiple overlaps in the receiver fields of view 1802, 1804, 1806, 1808, 1810, 1812. The receive fields of view 1802, 1804, 1806, 1808, 1810, 1812 are shown with different line types to help illustrate the overlap. In this configuration, multiple edges or overlapping areas between the transmit fields of view need to be managed to avoid optical crosstalk and also ensure eye safety. The controller module 1702 operates all of the transmit / receive modules 1706, 1708, 1710, 1712, 1714, 1716 to ensure that safety and performance specifications are met and to allow optimization of functions, such as tracking objects within the composite field of view 1800.

[0082] Fig.19 An embodiment of an operating scenario 1900 is illustrated, which includes a modular LIDAR system according to the present teachings, having two separate receivers 1902, 1904 and two separate transmitters 1906, 1908. In this operating scenario 1900, the two receivers 1902, 1904 each have an overall field of view equal to 30° and are configured to have some overlap in their fields of view to ensure that there are no gaps in coverage. This allows continuous tracking of, for example, pedestrians 1910, 1912, 1914. The two separate transmitters 1906, 1908 each contain multiple lasers. The two pairs of dashed lines 1916, 1918, 1920, 1922 starting from each transmitter show the projection angles of the two lasers within each transmitter. The two lasers are selected to correspond to pedestrians 1910, 1912, 1914. Pedestrian #1 1910 is only within the field of view of transmitter #1 1906 and receiver #1 1902. Pedestrian #3 1914 is only within the field of view of transmitter #2 1908 and receiver #2 1904. However, pedestrian #2 1912 is within the field of view of both transmitters 1906, 1908 and both receivers 1902, 1904.

[0083] Both receivers 1902, 1904 use a detector array. Each detector in the detector array has a field of view that is a subset of the overall receiver field of view. See e.g. Figure 7Band associated descriptions. In the illustrated operational scenario 1900, the field of view of each receiver is illustrated as being divided into three sections, each having a 10° field of view. For receiver #1 1902, these are regions 1A 1924, 1B 1926, and 1C 1928. For receiver #2 1904, these are regions 2A 1930, 2B 1932, and 2C 1934. A three-element detector array having uniform dimensions in the horizontal plane would correspond to the fields of view 1924, 1926, 1928, 1930, 1932, 1934 of either receiver 1902, 1904. It should be understood that the operational scenario 1900 is drawn for simplicity, and that in actual practice the dimensions of the detector array may be larger so that each individual detector has a smaller field of view. The field of view of each detector is uniquely labeled (1A, 1B, 1C, 2A, 2B, 2C) for reference.

[0084] A single controller 1938 may be used to control two receivers 1902 , 1904 and two transmitters 1906 , 1908 . Fig.19 The operational scenario 1900 shown in illustrates that pedestrian #1 is seen only by receiver #1, but by both detectors 1A and 1B. Pedestrian #2 can be seen by both receiver #1 and receiver #2 because the fields of view of detector 1C and detector 2A substantially overlap. The overlap is indicated by the diagonally shaded area 1936. The controller 1938 knows the specific fields of view 1924, 1926, 1928, 1930, 1932, 1934 corresponding to each detector element of the two receivers 1902, 1904, and therefore knows the overlapping area. The controller 1938 also knows the projection angles 1916, 1918, 1920, 1922 of the lasers within transmitter #1 1906 and within transmitter #2 1908, and therefore can calculate which detectors can be used at which range distances to measure the reflected pulses from each laser within each transmitter 1906, 1908.

[0085] The controller 1938 sets the laser excitation pattern of the lasers in the two transmitters 1906, 1908 and selects which detector or detector combination within all possible receivers 1902, 1904 to measure the return signal pulse. Typical criteria for selecting the best detector to measure each laser and range may include maximum received signal power or highest SNR. If the controller 1938 does not control the excitation pattern in the overlap region 1936 between the detectors in the two receivers 1902, 1904, there is the possibility of optical crosstalk leading to erroneous measurements. For example, pedestrian #2 1912 may be measured using either transmitter 1906, 1908. If the controller 1938 excites a pulse from transmitter #1 1906 at pedestrian #2 1912, and excites a second pulse from transmitter #2 1908 before the pulse is measured by the receivers 1902, 1904, then both pulses will be observed at a single detector during a single measurement. This will result in distance errors and / or detection of false objects. Controller 1938 controls the excitation pattern to maintain a strict one-to-one mapping between lasers and detectors during a single measurement within the field of view of the selected detector. This prevents optical crosstalk and measurement errors within the modular LIDAR system.

[0086] Fig. 20 A block diagram 2000 of an embodiment of a controller 2002 of the present teaching is illustrated. For simplicity, the controller 2002 is shown as communicating with two receivers 2004, 2006 and two transmitters 2008, 2010, while in actual use, there may be any number of receivers and controllers. The controller 2002 has various sets of information stored and available. This information may be determined during setup / calibration and / or updated during system operation. This information includes system constraints 2012. For example, system constraints may include a maximum duty cycle for a single laser, eye safety constraints on system operation, and other types of constraints. There is also laser data 2014, which includes the projection angle and origin of each laser relative to the corresponding transmitter. In addition, there is detector data 2016, which includes the field of view of each detector and the origin of each detector relative to its corresponding receiver. In addition, the controller 2002 has system position information 2018, for example, information about the position of each transmitter and receiver module within the system relative to some global origin and / or axis.

[0087] The controller 2002 may utilize TOF measurement information from the receiver as an additional input to determine laser selection and excitation pattern algorithms / processing.The TOF calculations may be performed within the same physical unit as the optical receiver, or may be performed elsewhere.

[0088] The controller 2002 executes an algorithm that controls the laser selection and excitation pattern. Since this is a solid-state system, there may be many types of excitation and scanning patterns within the field of view. In one embodiment of a method according to the present teachings, the controller 2002 performs a first step 2020 of selecting the laser to be emitted for each transmitter. In a second step 2022, the controller selects the corresponding detector. In a third step 2024, the controller checks for overlap of those lasers and detectors in the field of view. If there is no overlap that may cause errors and / or optical crosstalk, then the controller proceeds to a fourth step 2026 in which the lasers are excited. The corresponding return pulses are received at receiver #1 2004 and / or receiver #2 2006. If there is overlap, then the controller 2002 returns to the first step 2020 and selects a new set of lasers to excite accordingly and adjusts the excitation pattern as needed to accommodate the desired overlap conditions. After the return pulses are received by receiver #1 2004 and / or receiver #2 2006, a TOF analysis 2028 is performed. The results of analysis 2028 can be used in step 2020 to determine which excitation mode to proceed next.

[0089] Equivalent form

[0090] Although the applicant's teachings are described in conjunction with various embodiments, it is not intended that the applicant's teachings be limited to such embodiments. On the contrary, as will be appreciated by those skilled in the art, the applicant's teachings encompass various substitutions, modifications, and equivalent forms that can be made without departing from the spirit and scope of the present teachings.

Claims

1. A modular light detection and ranging LIDAR system comprising: a) a first optical transmitter, comprising a plurality of first emitters, the plurality of first emitters being configured to generate light beams that combine to have a first optical transmitter field of view (FOV) at a target range when activated, the first optical transmitter field of view at the target range being a combination of fields of view of each of the plurality of first emitters, the light beam generated by each of the plurality of first emitters corresponding to a projection angle subtending only a portion of the first optical transmitter field of view; b) a second optical transmitter, comprising a plurality of second emitters, the plurality of second emitters being configured to generate light beams that combine to have a second optical transmitter field of view at a target range when energized, the second optical transmitter field of view at the target range being a combination of fields of view of each of the plurality of second emitters, the light beam generated by each of the plurality of second emitters corresponding to a projection angle that subtends only a portion of the second optical transmitter field of view, wherein the first optical transmitter and the second optical transmitter are positioned relative to each other such that fields of view of at least some of the light beams generated by the first optical transmitter and the second optical transmitter when energized overlap at the target range; c) an optical receiver including a plurality of optical detectors, a respective one of the plurality of optical detectors being positioned to detect a respective light beam generated by at least one of the first optical transmitter and the second optical transmitter and reflected by a target in at least one of the first optical transmitter field of view and the second optical transmitter field of view at a target range; as well as d) a controller including first and second outputs connected to respective control inputs of the first and second optical transmitters, and a third output connected to a control input of the optical receiver, the controller generating control signals at the first and second outputs that control activation of selected ones of the plurality of first and second emitters to thereby illuminate a desired field of view at a target range; And generating a control signal at a third output terminal, the control signal activating a selected one of the plurality of light detectors to detect a light beam reflected from an object at the target range, thereby detecting light from a desired field of view at the target range.

2. The modular light detection and ranging LIDAR system of claim 1 , wherein the controller controls activation of selected ones of the plurality of first emitters and the plurality of second emitters, thereby illuminating a desired field of view at a target range, such that during a particular light detection and ranging measurement only one of the first light transmitter and the second light transmitter generates a light beam that is detected by one of the plurality of light detectors when reflected from an object at the target range.

3. The modular light detection and ranging LIDAR system of claim 1 , wherein the controller controls activation of selected ones of the plurality of first emitters and the plurality of second emitters to thereby illuminate a desired field of view at a target range such that crosstalk caused by light beams having overlapping fields of view at a target range is reduced.

4. The modular light detection and ranging LIDAR system of claim 1 , wherein the controller controls activation of selected ones of the plurality of first emitters and the plurality of second emitters to thereby illuminate a desired field of view at a target range such that crosstalk due to light beams having overlapping fields of view at the target range is minimized.

5. The modular light detection and ranging LIDAR system of claim 1 , wherein the controller generates control signals at the first output and the second output that control activation of selected ones of the plurality of first emitters and the plurality of second emitters to thereby illuminate a desired field of view at a target range such that optical power in an aperture at the target range is less than a predetermined amount.

6. The modular light detection and ranging LIDAR system of claim 5, wherein the predetermined amount is less than a maximum permissible exposure (MPE).

7. The modular light detection and ranging LIDAR system of claim 1, further comprising: a) a second optical receiver including a plurality of optical detectors, a respective one of the plurality of optical detectors in the second optical receiver being positioned to detect a respective light beam generated by at least one of the first optical transmitter and the second optical transmitter and reflected by a target in the field of view at the target range; as well as b) the controller further comprising a fourth output terminal connected to the control input terminal of the second light receiver, the controller generating a control signal at the fourth output terminal, the control signal activating a selected one of the plurality of light detectors in the second light receiver to detect the light beam reflected from the object at the target range, The controller generates control signals at the third output terminal and the fourth output terminal so that at a certain time only a selected light detector among the multiple light detectors in the first light receiver or the multiple light detectors in the second light receiver detects a light beam reflected from an object at a target range.

8. The modular light detection and ranging (LIDAR) system of claim 1, wherein the first optical transmitter and the second optical transmitter are housed in a single housing.

9. The modular light detection and ranging (LIDAR) system of claim 1, wherein the first optical transmitter and the second optical transmitter are housed in physically separate housings.

10. The modular light detection and ranging (LIDAR) system of claim 1, wherein the optical receiver is housed in a housing that is physically separate from a housing that houses the first optical transmitter and the second optical transmitter.

11. The modular light detection and ranging (LIDAR) system of claim 1 , wherein at least one of the first optical transmitter and the second optical transmitter is housed in the same housing as the optical receiver.

12. The modular light detection and ranging (LIDAR) system of claim 1, wherein at least one of the first and second optical transmitters, the optical receiver, and the controller are housed in a same housing.

13. The modular light detection and ranging (LIDAR) system of claim 1, wherein the plurality of light detectors in the light receiver comprises a two-dimensional array.

14. The modular light detection and ranging (LIDAR) system of claim 1, wherein the plurality of first emitters in the first optical transmitter comprises a two-dimensional array of emitters.

15. The modular light detection and ranging (LIDAR) system of claim 14, wherein the two-dimensional array of emitters comprises a matrix-addressable array of emitters.

16. The modular light detection and ranging (LIDAR) system of claim 1, wherein the plurality of first emitters in the first optical transmitter comprises first and second two-dimensional arrays of emitters.

17. The modular light detection and ranging (LIDAR) system of claim 16, wherein the first and second two-dimensional arrays of emitters generate light beams having interleaved fields of view.

18. The modular light detection and ranging (LIDAR) system of claim 1, wherein the plurality of first emitters in the first optical transmitter comprises a VCSEL array.

19. The modular light detection and ranging (LIDAR) system of claim 1, wherein the plurality of first emitters generate light beams at a first wavelength and the plurality of second emitters generate light beams at a second wavelength.

20. The modular light detection and ranging (LIDAR) system of claim 1, wherein at least two of the plurality of first emitters generate light beams of different wavelengths.

21. The modular light detection and ranging (LIDAR) system of claim 1, wherein the controller generates control signals at the first output and the second output, the control signals controlling activation of selected ones of the plurality of first emitters and the plurality of second emitters based on relative positions of the first optical transmitter and the second optical transmitter.

22. The modular light detection and ranging LIDAR system of claim 1 , wherein the controller generates control signals at the first output, the second output, and the third output, the control signals controlling the excitation of selected ones of the plurality of first emitters and the plurality of second emitters and controlling the activation of selected ones of the plurality of light detectors based on the relative positions of the first light transmitter, the second light transmitter, and the light receiver.

23. A modular light detection and ranging LIDAR system comprising: a) a first optical transmitter comprising first and second two-dimensional arrays of emitters which, when energized, generate first and second arrays of light beams interleaved to have a first optical transmitter field of view at a target range, the first optical transmitter field of view at the target range being a combination of the fields of view of each of the first and second two-dimensional arrays of emitters of the first optical transmitter, the first and second arrays of light beams generated by each of the first and second two-dimensional arrays of emitters of the first optical transmitter corresponding to a projection angle subtending only a portion of the first optical transmitter field of view; b) a second optical transmitter comprising first and second two-dimensional arrays of emitters which, when energized, generate first and second arrays of light beams interleaved to have a field of view of the second optical transmitter at a target range, the second optical transmitter field of view at the target range being a combination of the fields of view of each of the first and second two-dimensional arrays of emitters of the second optical transmitter, the first and second arrays of light beams generated by each of the first and second two-dimensional arrays of emitters of the second optical transmitter corresponding to projection angles subtending only a portion of the second optical transmitter field of view, wherein the first optical transmitter and the second optical transmitter are positioned such that at least some of the first and second arrays of light beams generated by the first optical transmitter when energized overlap with at least some of the first and second arrays of light beams generated by the second optical transmitter when energized at the target range; c) an optical receiver including a plurality of optical detectors, a respective one of the plurality of optical detectors being positioned to detect a respective light beam generated by at least one of the first optical transmitter and the second optical transmitter and reflected by a target in at least one of the first optical transmitter field of view and the second optical transmitter field of view at a target range; as well as d) a controller including first and second outputs connected to respective control inputs of the first and second optical transmitters and a third output connected to a control input of the optical receiver, the controller generating control signals at the first and second outputs that control activation of selected emitters in the first and second two-dimensional arrays of emitters in both the first and second optical transmitters to thereby illuminate a desired field of view at a target range when activated; And generating a control signal at a third output terminal, the control signal activating a selected one of the plurality of light detectors to detect a light beam reflected from an object at the target range, thereby detecting light from a desired field of view at the target range.

24. The modular light detection and ranging (LIDAR) system of claim 23, wherein the relative positions of the first and second arrays of at least one of the first and second light transmitters are selected to provide a desired angular resolution of the modular light detection and ranging system.

25. The modular light detection and ranging (LIDAR) system of claim 23, wherein in at least one of the first optical transmitter and the second optical transmitter, a wavelength of the first two-dimensional array of emitters is different than a wavelength of the second two-dimensional array of emitters.

26. The modular light detection and ranging LIDAR system of claim 23, wherein the controller controls activation of selected emitters in the first and second two-dimensional arrays of emitters in both the first and second light transmitters to illuminate a desired field of view at a target range when activated, such that during a particular light detection and ranging measurement only one of the first and second light transmitters generates a light beam that is detected by one of the plurality of light detectors when reflected from an object at the target range.

27. A modular light detection and ranging LIDAR system as described in claim 23, wherein the controller controls the activation of selected emitters in the first and second two-dimensional arrays of emitters in both the first optical transmitter and the second optical transmitter to illuminate a desired field of view at a target range when activated, thereby reducing crosstalk caused by light beams having overlapping fields of view at the target range.

28. A modular light detection and ranging LIDAR system as described in claim 23, wherein the controller controls the activation of selected emitters in the first and second two-dimensional arrays of emitters in both the first optical transmitter and the second optical transmitter to illuminate a desired field of view at a target range when activated so as to minimize crosstalk caused by light beams having overlapping fields of view at the target range.

29. A modular light detection and ranging LIDAR system as described in claim 23, wherein the controller controls the excitation of selected emitters in the first and second two-dimensional arrays of emitters in both the first optical transmitter and the second optical transmitter, thereby illuminating a desired field of view at a target range when excited so that the optical power in the aperture at the target range is less than a predetermined amount.

30. The modular light detection and ranging LIDAR system of claim 29, wherein the predetermined amount is less than a maximum permissible exposure (MPE).

31. The modular light detection and ranging LIDAR system of claim 23, further comprising: a) a second optical receiver including a plurality of optical detectors, a respective one of the plurality of optical detectors being positioned to detect a respective light beam generated by at least one of the first optical transmitter and the second optical transmitter and reflected by a target in the field of view at the target range; as well as b) the controller further comprising a fourth output terminal connected to the control input terminal of the second light receiver, the controller generating a control signal at the fourth output terminal, the control signal activating a selected one of the plurality of light detectors in the second light receiver to detect the light beam reflected from the object at the target range, The controller generates control signals at the third output terminal and the fourth output terminal so that at a certain time only a selected light detector among the multiple light detectors in the first light receiver or the multiple light detectors in the second light receiver detects a light beam reflected from an object at a target range.

32. The modular light detection and ranging (LIDAR) system of claim 23, wherein the first optical transmitter and the second optical transmitter are housed in a single housing.

33. The modular light detection and ranging (LIDAR) system of claim 23, wherein the first optical transmitter and the second optical transmitter are housed in physically separate housings.

34. The modular light detection and ranging (LIDAR) system of claim 23, wherein the optical receiver is housed in a housing that is physically separate from a housing that houses the first optical transmitter and the second optical transmitter.

35. The modular light detection and ranging (LIDAR) system of claim 23, wherein at least one of the first optical transmitter and the second optical transmitter is housed in the same housing as the optical receiver.

36. The modular light detection and ranging (LIDAR) system of claim 23, wherein at least one of the first and second optical transmitters, the optical receiver, and the controller are housed in a same housing.

37. The modular light detection and ranging (LIDAR) system of claim 23, wherein the plurality of light detectors in the light receiver comprises a two-dimensional array.

38. The modular light detection and ranging (LIDAR) system of claim 23, wherein at least one of the first and second two-dimensional arrays of at least one of the first optical transmitter and the second optical transmitter comprises a VCSEL array.

39. A modular light detection and ranging (LIDAR) method, the method comprising: a) when excited by a plurality of first emitters in a first optical transmitter, generating a plurality of light beams that combine to have a first optical transmitter field of view (FOV) at a target range, the first optical transmitter field of view at the target range being a combination of the fields of view of each of the plurality of first emitters, the light beam generated by each of the plurality of first emitters corresponding to a projection angle subtending only a portion of the first optical transmitter field of view; b) when excited by a plurality of second emitters in the second optical transmitter, generating a plurality of light beams that combine to have a second optical transmitter field of view at a target range, the second optical transmitter field of view at the target range being a combination of fields of view of each of the plurality of second emitters, the light beam generated by each of the plurality of second emitters corresponding to a projection angle subtending only a portion of the second optical transmitter field of view; c) positioning the first optical transmitter and the second optical transmitter relative to each other such that fields of view of at least some of the optical beams generated by the first optical transmitter and the second optical transmitter when energized overlap at the target range; d) positioning a plurality of optical detectors such that a corresponding detector of the plurality of optical detectors detects an optical beam generated by at least one of a first optical transmitter and a second optical transmitter that is reflected by a target in at least one of a field of view of the first optical transmitter and a field of view of the second optical transmitter at a target range; as well as e) energizing selected ones of the plurality of first emitters and the plurality of second emitters, thereby illuminating a desired field of view at a target range, and activating selected ones of the plurality of light detectors to detect light beams reflected from an object at the target range, thereby detecting light from the desired field of view at the target range.

40. The modular light detection and ranging LIDAR method of claim 39, further comprising: Selected ones of the plurality of first emitters and the plurality of second emitters are energized to thereby illuminate a desired field of view at a target range so that only one of the first optical transmitter and the second optical transmitter generates a light beam that is detected by one of the plurality of light detectors when reflected from an object at the target range during a particular light detection and ranging measurement.

41. The modular light detection and ranging LIDAR method of claim 39, further comprising: Selected ones of the plurality of first emitters and the plurality of second emitters are energized to thereby illuminate a desired field of view at a target range such that crosstalk caused by light beams having overlapping fields of view at the target range is reduced.

42. The modular light detection and ranging LIDAR method of claim 39, further comprising: Selected ones of the plurality of first emitters and the plurality of second emitters are energized to thereby illuminate a desired field of view at a target range such that optical power in a particular eye-safe measurement aperture is less than a predetermined amount.

43. The modular light detection and ranging (LIDAR) method of claim 39, wherein the plurality of light beams generated by a first emitter have a first wavelength and the plurality of light beams generated by a second emitter have a second wavelength.

44. The modular light detection and ranging (LIDAR) method of claim 39, wherein at least two of the plurality of first emitters generate light beams of different wavelengths.

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