Lidar speed measurements

Abstract

Different illumination lines, generated by a first and a second laser separated by a selectable angle between 1 and 15 degrees, are swept across a field of view using a scanning mirror. This is done in such a way that an object is illuminated successively with a known time delay, determined by the angular separation and the mirror movement. Reflections from the object are detected by corresponding detectors, and the data from these events is processed to generate position information for each illumination. By analyzing the change in the object's position between the captured data points and incorporating a controlled time delay, a velocity measurement of the object is calculated.

Description

This application claims priority over US Provisional Application No. US 63 / 739,911, filed on December 30, 2024, which is hereby fully incorporated by reference for all purposes. Three-dimensional sensors are components in a variety of rapidly growing fields, including autonomous vehicles, drones, robots, and security applications. Lidar systems, in particular, are capable of generating detailed three-dimensional images of an environment or parts thereof by projecting an optical beam and capturing the light reflected from objects. A time-of-flight (ToF) calculation, based on the time difference between the emission of the optical beam and the detection of its reflection, allows the system to determine the distance to various points on the object, thereby generating a "point cloud" that represents the 3D environment. Sampling lidar systems can achieve high angular resolution at relatively affordable costs, making them suitable for mass-market applications. Examples of sampling lidar systems are detailed in U.S. Patent No. 10,690,754, issued on June 23, 2020, and U.S. Patent Application No. 18 / 531,507, filed on December 6, 2023, which are hereby fully incorporated by reference for all purposes. However, improved scanning systems, devices, and / or methods are desirable. In some configurations, a lidar system comprises a first laser configured to generate a first illumination line in a field of view; a second laser configured to generate a second illumination line in the field of view, wherein the second illumination line is angularly separated from the first illumination line by a known angle, and the known angle being between 1 and 15 degrees; a scanning mirror configured to pivot the first and second illumination lines across the field of view, wherein an object in the field of view is illuminated by the second illumination line with a known time delay after it has been illuminated by the first illumination line, wherein the known time delay is a function of the known angle; and a first detector configured to detect a first reflection of the first laser from the object.a second detector configured to detect a second reflection of the second laser from the object; and / or a processing unit configured to generate a first sub-image of the object based on data acquired from reflections of the first laser, including acquiring the first reflection, wherein the first sub-image is a first point cloud, generating a second sub-image of the object based on data acquired from reflections of the second laser, including acquiring the second reflection, wherein the second sub-image is a second point cloud, and / or calculating a three-dimensional velocity vector of the object by analyzing a change in the object's position between the first and second sub-images, and the known time delay. In some cases, the first laser is part of a first laser array and the second laser is part of a second laser array.wherein the first laser and the second laser share a focusing lens; wherein the first laser array, the second laser array, the first detector, the second detector and the processing unit are located on the same chip; and / or wherein the scanning mirror is an oscillating mirror or a rotating polygonal mirror. In some configurations, a lidar system comprises a first laser configured to generate a first illumination line in a field of view; a second laser configured to generate a second illumination line in the field of view, the second illumination line being angularly offset from the first illumination line by a known angle; a scanning mirror configured to pan the first and second illumination lines across the field of view, wherein an object in the field of view is illuminated by the second illumination line with a known time delay after it has been illuminated by the first illumination line, the known time delay being based on the known angle; and a first detector configured to detect a first reflection of the first laser from the object.a second detector configured to detect a second reflection of the second laser from the object; and / or a processing unit configured to calculate a first position of the object based on the first reflection, a second position of the object based on the second reflection, and / or a velocity of the object based on the difference between the first and second positions and the known time delay. In some configurations, the known angle is between 1 and 15 degrees; the known time delay is a function of the known angle and an angular velocity of the scanning mirror;The processing unit is further configured to calculate a three-dimensional velocity vector of the object by analyzing a change in the object's position between a first sub-image generated on the basis of data acquired from reflections of the first laser and a second sub-image generated on the basis of data acquired from reflections of the second laser; the first laser is part of a first laser array and the second laser is part of a second laser array; the first laser array and the second laser array share a focusing lens; the first laser array, the second laser array, the first detector, the second detector, and the processing unit are located on the same chip; the scanning mirror is an oscillating mirror or a rotating polygonal mirror. In certain embodiments, a method for detecting the velocity of an object using lidar comprises: emitting light from a first laser configured to generate a first illumination line; emitting light from a second laser configured to generate a second illumination line; wherein the second illumination line differs angularly from the first illumination line by a known angle; pivoting the first and second illumination lines over a field of view by means of a scanning mirror; wherein an object in the field of view is illuminated by the second illumination line with a known time delay after it has been illuminated by the first illumination line; and detecting, by means of at least one detector array, reflections of the first and second illumination lines from the object.and calculating a first position of the object based on the detection of the first reflection from the first illumination line; calculating a second position of the object based on the detection of the second reflection from the second illumination line; and / or calculating a velocity of the object based on a difference between the first and second positions and the known time delay. In some configurations, the known angle is between 1 and 15 degrees; the known time delay is a function of the known angle and an angular velocity of the scanning mirror;The method further comprises calculating a three-dimensional velocity vector of the object by analyzing a change in the object's position between a first sub-image generated on the basis of data acquired from reflections of the first laser and a second sub-image generated on the basis of data acquired from reflections of the second laser; the first laser is part of a first laser array and the second laser is part of a second laser array; the first laser array and the second laser array share a focusing lens; the first laser array, the second laser array, the first detector, the second detector, and the processing unit are located on the same chip; the scanning mirror is an oscillating mirror or a rotating polygonal mirror. In some embodiments, the lidar system comprises a first laser source configured to emit light at a first wavelength; a second laser source configured to emit light at a second wavelength different from the first; a scanning mirror configured to pan light from the first laser source across a first field of view, pan light from the second laser source across a second field of view, and receive light reflected from the first and second fields of view; and a beam splitter configured to receive the light reflected from the scanning mirror, the beam splitter being configured to separate the reflected light into a first optical path corresponding to the first wavelength and a second optical path corresponding to the second wavelength.A first detector arranged in the first optical path for detecting reflected light of the first wavelength; and / or a second detector arranged in the second optical path for detecting reflected light of the second wavelength. In some configurations, the system further comprises a first lens with a first focal length in the first optical path; and / or a second lens with a second focal length in the second optical path, wherein the second focal length is longer than the first focal length. In certain embodiments, the first optical path is optimized for a first detection range; a first field of view, and the second optical path is optimized for a second detection range and a second field of view, wherein the second detection range is longer than the first detection range and the second field of view is narrower than the first field of view; the first wavelength and the second wavelength are between 850 nm and 960 nm.the first wavelength is 905 nm, plus / minus 10 nm, and the second wavelength is 940 nm, plus / minus 10 nm, and / or the system further comprises a processing unit designed to generate a three-dimensional point cloud by combining data from at least the first detector and the second detector. In certain embodiments, a lidar method for detecting near and far objects comprises: emitting a first laser pulse within a first field of view, wherein the first laser pulse is characterized by a first wavelength; emitting a second laser pulse within a second field of view, wherein the second laser pulse is characterized by a second peak wavelength; receiving reflected light from the first and second fields of view; separating the reflected light into a first optical path corresponding to the first wavelength and a second optical path corresponding to the second wavelength; detecting, by means of a first detector arranged in the first optical path, reflected light of the first wavelength; and detecting, by means of a second detector arranged in the second optical path, reflected light of the second wavelength.Calculating a first distance to a first object in the first field of view based on the first detector, which detects reflected light corresponding to the first wavelength; and / or calculating a second distance to a second object in the second field of view based on the second detector, which detects reflected light corresponding to the second wavelength. In certain configurations, the method further comprises guiding light of the first wavelength through a first lens with a first focal length, wherein the first lens is located in the first optical path, and guiding light of the second wavelength through a second lens with a second focal length, wherein the second lens is located in the second optical path. In certain embodiments, a method for measuring distances using a lidar system comprises: emitting a first laser pulse into a first field of view; emitting a second laser pulse into a second field of view; upon detecting a reflection from the first laser pulse from a first detector, initiating a first time-of-flight measurement to calculate a first distance to a first object in the first field of view; waiting for a predetermined time delay after the emission of the second laser pulse before detecting a reflection from the second laser pulse; initiating a second time-of-flight measurement based on the reflection of the second laser pulse; and / or calculating a second distance to a second object in the second field of view based on the second time-of-flight measurement, wherein the second area is located farther away from the lidar system than the first area.In some configurations, the predetermined time delay corresponds to the round-trip travel time of light at a minimum distance of the second field of view; the minimum distance of the second area is equal to or greater than 250 meters; and / or the first field of view and the second field of view overlap at least partially. The broad range of applications of this disclosure will become apparent from the detailed description below. It should be understood that the detailed description and specific examples illustrating various embodiments are provided for clarification purposes only and are not intended to limit the scope of the disclosure. Embodiments of the invention are explained in more detail below with reference to the accompanying figures. Fig. 1 shows an embodiment of a lidar sensor for three-dimensional imaging. Fig. 2 shows an embodiment of a lidar system in which two different wavelengths are used to simultaneously measure shorter and longer distances. Fig. 3 is an exemplary graphical representation of two fields of view for the dual-wavelength lidar system of Fig. 2. Fig. 4 is a schematic diagram of an embodiment of a lidar system designed for high-speed measurement using two angularly separated laser arrays. Fig. 5 is a graph showing the relationship between the angular separation of laser arrays, the accuracy of the distance measurement, and the minimum resolvable speed for the exemplary lidar system shown in Fig. 4.Figure 6 shows a flowchart of an embodiment of a lidar method for detecting near and distant objects. Figure 7 shows a flowchart of an embodiment of a method for measuring distant distances using a lidar system. Figure 8 shows a flowchart of an embodiment of a method for detecting the velocity of an object using lidar. In the accompanying drawings, similar components and / or features may share the same reference numeral. Furthermore, various components of the same type may be distinguished by a hyphen following the reference numeral, followed by a second designation that differentiates between the similar components. If only the first reference numeral is used in the description, the description applies to all similar components with the same first reference numeral, regardless of the second reference numeral. The following description presents exemplary embodiment(s) and is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the following description of preferred exemplary embodiments will provide those skilled in the art with an executable description for implementing a preferred exemplary embodiment. It should be understood that various modifications to the functionality and arrangement of elements can be made without departing from the concept and scope of the appended claims. Additional examples of lidar systems are provided in US patent application No. 18 / 787,427, filed on July 29, 2024, and US patent application No. 19 / 027,522, filed on January 17, 2025, by the same applicant, which are incorporated by reference for all purposes. This disclosure relates to general scanning lidar systems. For example, some embodiments relate to the use of two different wavelengths for short-range and long-range acquisition, by means of a time delay for measuring longer distances, and / or by means of two lasers spaced a few degrees apart for extracting velocity measurements. Fig. 1 shows an embodiment of a lidar sensor 100 for three-dimensional imaging. The lidar sensor 100 includes an emission lens 130 and a receiving lens 140. The lidar sensor 100 includes a light source 110-a, arranged substantially in a rear focal plane of the emission lens 130. The light source 110-a is configured to emit a light pulse 120 from a corresponding emission position in the rear focal plane of the emission lens 130. The emission lens 130 is configured to collimate the light pulse 120 and direct it onto an object 150 located in front of the lidar sensor 100. For a given emission position of the light source 110-a, the collimated light pulse 120' is directed at the object 150 at a corresponding angle. A component 122 of the collimated light pulse 120' is reflected from the object 150 towards the receiving lens 140. The receiving lens 140 is configured to focus the component 122' of the light pulse reflected from the object 150 onto a corresponding detection point in the focal plane of the receiving lens 140. The lidar sensor 100 further comprises a detector 160-a arranged substantially in the focal plane of the receiving lens 140. The detector 160-a is configured to receive the component 122' of the light pulse 120 reflected from the object 150 and to detect it at the corresponding detection point. The corresponding detection point of the detector 160-a is optically conjugate to the corresponding emission point of the light source 110-a. The light pulse 120 can be of short duration, for example, with a pulse width of 10 ns. The lidar sensor also includes a processor 190 coupled to the light source 110-a and the detector 160-a. The processor 190 is configured to determine the time of flight (TOF) of the light pulse from emission to detection. Since the light pulse 120 propagates at the speed of light, a distance between the lidar sensor 100 and the object 150 can be determined based on the calculated time of flight. One way to pan a laser beam (e.g., light pulse 120) across a field of view (FOV) is to laterally shift the light source 110-a relative to the emission lens 130 in the rear focal plane of the emission lens 130. For example, the light source 110-a can be scanned to several emission locations in the rear focal plane of the emission lens 130, as shown in Fig. 1. The light source 110-a can emit multiple light pulses at these emission locations. Each light pulse emitted at a corresponding emission location is collimated by the emission lens 130 and directed at the object 150 at a corresponding angle, striking the surface of the object 150 at a corresponding point. Thus, while the light source 110-a is scanned within a certain area in the rear focal plane of the emission lens 130, a corresponding area of ​​the object 150 is scanned.The detector 160-a can be moved for scanning purposes to be positioned at several corresponding detection locations in the focal plane of the receiving lens 140, as shown in Fig. 1. Scanning of the detector 160-a is typically performed synchronously with scanning of the light source 110-a, so that the detector 160-a and the light source 110-a are optically conjugate to each other at all times. By determining the transit time for each light pulse emitted at a given emission point, the distance from the lidar sensor 100 to each corresponding point on the surface of the object 150 can be determined. In some embodiments, the processor 190 is coupled with a position encoder that detects the position of the light source 110-a at each emission point. Based on the emission point, the angle of the collimated light pulse 120' can be determined. The XY coordinate of the corresponding point on the surface of the object 150 can be determined based on the angle and the distance to the lidar sensor 100. Thus, a three-dimensional image of the object 150 can be constructed based on the measured distances from the lidar sensor 100 to various points on the surface of the object 150. In some embodiments, the three-dimensional image can be represented as a point cloud, i.e.,a set of X, Y and Z coordinates of the points on the surface of object 150. In some embodiments, the intensity of the returning light pulse 122' is measured and used to adjust the power of subsequent light pulses from the same emission point to avoid detector saturation, improve eye safety, or reduce overall power consumption. The power (energy) of the light pulses can be varied by varying the duration of the light pulses, the voltage or current applied to the laser, or the charge stored in a capacitor used to operate the laser. In the latter case, the charge stored in the capacitor can be varied by varying the charging time, charging voltage, or charging current to the capacitor. In some embodiments, the reflectivity, as determined by the intensity of the detected pulse, can also be used to add another dimension to the image.For example, the image can include X, Y and Z coordinates as well as reflectivity (or brightness). The angular field of view (AFOV) of the lidar sensor 100 can be estimated based on the swivel range of the light source 110-a and the focal length of the emission lens 130, where h is the swivel range of the light source 110-a along a certain direction, and f is the focal length of the emission lens 130. For a given swivel range h, shorter focal lengths would result in wider AFOVs. For a given focal length f, larger swivel ranges would result in wider AFOVs. In some embodiments, the lidar sensor 100 can include multiple light sources arranged as an array at the rear focal plane of the emission lens 130, so that a larger overall AFOV can be achieved while keeping the swivel range of each individual light source relatively small.Accordingly, the lidar sensor 100 can include multiple detectors arranged as an array at the focal plane of the receiving lens 140, each detector being conjugated to a corresponding light source. For example, the lidar sensor 100 can include a second light source 110-b and a second detector 160-b, as shown in Fig. 1. In other embodiments, the lidar sensor 100 can include four light sources and four detectors, or eight light sources and eight detectors. In one embodiment, the lidar sensor 100 can include eight light sources arranged as a 4×2 array and eight detectors arranged as a 4×2 array, such that the lidar sensor 100 has a wider AFOV in the horizontal direction than its AFOV in the vertical direction.According to various embodiments, the total AFOV of the Lidar sensor 100 can range from about 5 degrees to about 15 degrees, or from about 15 degrees to about 45 degrees, or from about 45 degrees to about 120 degrees, depending on the focal length of the emission lens, the swivel range of each light source, and the number of light sources. The light source 110-a can be configured to emit light pulses in the near-infrared wavelength range. The energy of each light pulse can be on the order of microjoules, which can be considered eye-safe for repetition rates in the kHz range. For light sources operating at wavelengths greater than approximately 1500 nm (in the near-infrared wavelength range), the energy levels could be higher because the eye does not focus at such wavelengths. The detector 160-a can comprise a silicon avalanche photodiode, a photomultiplier, a PIN diode, or other semiconductor sensors. Further lidar sensors are described in the applicant's US patent applications 15 / 267,558, filed on September 15, 2016; 15 / 971,548, filed on May 4, 2018; 16 / 504,989, filed on July 8, 2019; 16 / 775,166, filed on January 28, 2020; 17 / 032,526, filed on September 25, 2020; 17 / 133,355, filed on December 23, 2020; 17 / 205,792, filed on March 18, 2021; and 17 / 380,872, filed on July 20, 2021, which are hereby fully incorporated by incorporation for all purposes. In some lidar systems, light from an array of lasers is swept horizontally across a field of view (FOV) by a oscillating mirror. In some configurations, light from the laser array is projected through a transmission lens system (e.g., comprising one or more lenses). Light reflected from objects in the FOV is received by the oscillating mirror and imaged onto a detector array. In some configurations, a receiving lens system (e.g., comprising one or more lenses) is used to image light from the oscillating mirror onto the detector array. The laser array can be a VCSEL array or a single laser with non-cylindrical optics to form a line image. A detector array can be a single monolithic array of silicon single-photon avalanche diodes (SPADs) and / or other types of photosensors such as avalanche photodetectors (APDs).The laser and detector arrays are arranged to cover the vertical field of view (FOV), so that the entire FOV can be covered when the array is panned horizontally. In some implementations, a rotating polygonal mirror can be used instead of a oscillating mirror. A signal from a detector in the detector array is analyzed by a processing unit, and the time-of-flight (ToF) difference between a laser pulse and the received light is used to verify (e.g., measure) the distance to an object within the field of view (FOV). Multiple signals from the detector are used to construct a 3D image of the FOV (e.g., to generate a three-dimensional point cloud). In some situations, it can be difficult to cover both near and far objects with adequate spatial and temporal (e.g., distance) resolution. Furthermore, some ToF designs do not provide instantaneous (or near-instantaneous) information about an object's velocity. A. Dual-wavelength architecture for multi-range sensing Fog. 2 depicts an embodiment of a lidar system 200 that uses two different wavelengths to simultaneously measure shorter distances with a wider field of view and longer distances with a narrower field of view. It can be challenging to design a single optical system that provides adequate spatial and temporal resolution for both near-field and far-field objects simultaneously. A configuration optimized for long-range detection may have a narrower field of view (FOV) and poor resolution at close range, while a wide-FOV system for near-field detection may lack the power and resolution to effectively detect distant objects. Figure 2 shows an embodiment that overcomes one or more of these difficulties. Two sets of lasers with different wavelengths are used, with a first set optimized for the near field and / or wide FOV, and a second set optimized for the far field and / or narrower FOV. For example, the second set of lasers may have higher power or be focused into a narrow line. For clarity, the lasers and / or transmission optics in Figure 2 are not shown.Figure 2 is not shown. For a detection path, a beam splitter is used to direct the first wavelength to one set of detectors and the second wavelength to a second set of detectors. The imaging lens for the second set of detectors may have a longer focal length to improve resolution and / or light capture from the greater distance, perhaps at the cost of a reduced field of view. In the example shown, the lidar system 200 uses a first laser 204. The first laser 204 operates at a first wavelength (e.g., a peak wavelength of 905 nm ± 5 nm). In some configurations, the first laser 204 is part of a first laser array (e.g., the laser array extends in and / or out of the plane of the leaf and / or includes additional pillars). Each laser in the first laser array is configured to operate at the first wavelength. The first laser 204 (and, if used, the first laser array) is optimized for a wide field of view and short range. The Lidar system 200 includes a second laser 208. The first laser 204 operates at a second wavelength (e.g., 940 nm ±5 nm). In some configurations, the second laser 208 is part of a second laser array (e.g., the laser array extends in and / or out of the plane of the leaf and / or includes additional columns). Each laser in the second laser array is configured to operate at the second wavelength. The second laser 208 (and, if used, the second laser array) is optimized for a narrow field of view and long range. Light from the first laser 204 and light from the second laser 208 is transmitted via a scanning mirror 212 and through an IR window 216 into one or more fields of view of an environment. The swivel mirror 212 can be configured to oscillate back and forth (e.g., about a pivot point 218), or the swivel mirror 212 can rotate in a circle (e.g., as part of a polygonal mirror). The example shown in Fig. 2 shows an oscillating swivel mirror. Light from the first laser 204 passes through a beam splitter 220 before reaching the scanning mirror 212. The second laser 208 is reflected by the beam splitter 220 before reaching the scanning mirror 212. The beam splitter 220 can be a "hot" mirror or a "cold" mirror. A hot mirror reflects light wavelengths longer than a cutoff wavelength, and a cold mirror reflects light wavelengths shorter than a cutoff wavelength. In the example shown in Fig. 2, the beam splitter 220 is a hot mirror, which reflects longer light wavelengths and transmits shorter light wavelengths. For example, the hot mirror acting as beam splitter 220 has a cutoff wavelength of about 920 nanometers, so that wavelengths higher than 920 nanometers are reflected and wavelengths shorter than 920 nanometers are transmitted. Light reflected from the surroundings is collected by the scanning mirror 212 and directed onto the beam splitter 220. The beam splitter 220 is configured to transmit light of the first wavelength (e.g., 905 nm) and reflect light of the second wavelength (e.g., 940 nm), or vice versa. The light of the first wavelength is directed along a first optical path. A first lens 224 is arranged in the first optical path. The first optical path extends from the beam splitter 220 to a first detector 228. Light passing through the first lens 224 is focused onto the first detector 228. The first detector 228 can be part of a first detector array. For example, the first detector array comprises one or more columns of detectors extending in and / or out of the plane of the sheet. The light of the second wavelength is directed along a second optical path. A second lens 230 is arranged in the second optical path. The second optical path extends from the beam splitter 220 to a second detector 232. Light passing through the second lens 230 is focused onto the second detector 232. The second detector 232 can be part of a second detector array. For example, the second detector array comprises one or more columns of detectors extending in and / or out of the plane of the sheet. The first optical path is optimized for short-range detection and provides a wide field of view. The second optical path is optimized for long-range detection and provides a narrower field of view than the first optical path. The first lens 224 has a shorter focal length than the second lens 230. The longer focal length of the second lens 230 provides higher magnification, which improves angular resolution and light-gathering efficiency for distant objects. The first lens 224 and the second lens 230 can be simple lenses or optical assemblies (e.g., optical assemblies with an arrangement of optical components such as one or more lenses, mirrors, prisms, apertures, etc.). The first lens 224 (and analogously the second lens) can be used to focus light onto exactly one detector, exactly one column of the first detector array, or several detector columns of the first detector array. In some embodiments, light from the first laser 204 also passes through the first lens 224, whereas in other configurations, light from the first laser 204 passes through a lens separate from the first lens 224. In some configurations, light from the second laser 208 also passes through the second lens 230, whereas in other configurations, light from the second laser 208 passes through a lens separate from the second lens 230. While wavelengths of 905 nm and 940 nm are given as examples, other wavelengths (e.g., those that can be optically separated) are possible. For example, light within the range of 850 nm and 960 nm is used. Light with a wavelength of 850 nm is marginally visible. Light of the first wavelength and light of the second wavelength are each characterized by a peak wavelength (e.g., the peak wavelength of the first light is 905 nm and the peak wavelength of the second light is 940 nm). In some configurations, the first wavelength is separated from the second wavelength by at least 10, 20, or 30 nm and at most 30, 50, or 60 nm. A processing unit 240 is configured to calculate the travel time of light emitted by the laser, reflected by an object in a field of view, and returned to a detector. In some configurations, a detector (and array) and a laser (and array) and / or the processing unit are integrated on a single chip. In some configurations, each detector array has its own processing unit. Fig. 3 is an exemplary graphical representation of two fields of view for the Lidar system 200 from Fig. 2. Fig. 3 shows a first field of view (FOV) 304 and a second FOV 308. The first FOV 305 (e.g. using 905 nm light) is for long-range and close-range detection, and the second FOV 308 (e.g. using 940 nm light) is for narrower and longer-range detection. As shown in Fig. 3, this architecture results in two distinct but complementary detection zones. For example, the first FOV 304 has a horizontal FOV, H-1 = 120 degrees, and a vertical FOV (in and out of the side) of ±25°, with an effective range R-1 of 0.1 to 300 meters; the second FOV 308 has a narrower horizontal FOV, H-2 = 60 degrees, and a vertical FOV of ±12°, with an effective range R-2 of 200 to 500 meters. The system can be designed with an overlap region 312 (e.g., between 200 m and 300 m) in which both subsystems can detect objects, enabling sensor fusion and robust performance. B. Time-delayed distance measurement for increased far-field accuracy Time-delayed distance measurement can be used to improve the accuracy of long-range measurements. In Time-of-Flight (ToF) systems, measuring long distances with high accuracy often requires complex and / or high-frequency counters. To simplify this, a time delay can be introduced into the measurement process for the long-range detectors. The counter is only initiated after a delay corresponding to the travel time of light for a minimum desired distance (e.g., a range equal to or greater than 200, 225, 250, 255, 260, 270, or 300 meters). This allows the system to use a high-resolution counter over a specific, limited long-range window, increasing accuracy without requiring an overly complex design. In some configurations, the measurement process for long-range FOV (e.g., the second FOV 308 in Fig. 3) is enhanced. For example, in the second detector 232 (and the second detector array) in Fig. 2, the ToF counter is not started immediately after emission of a laser pulse from the second laser 208. Instead, the processing unit inserts a fixed time delay before initiating the count that detects light at the second detector 232. This delay corresponds to the round-trip travel time at a minimum limit distance, for example, 200 or 250 meters. By starting the measurement only after this delay, the system effectively ignores reflections from objects closer than 200 or 250 meters on this channel and can dedicate the full dynamic range of its counter to the desired long-range window (e.g., 250 m to 500 m).This allows for higher temporal resolution and therefore more precise distance measurements within that specified range, without using an excessively complex or expensive high-speed counter. C. Dual-array architecture for speed measurement Conventional lidar systems do not directly measure an object's velocity. Velocity can be inferred by comparing an object's position across multiple successive data frames. Often, a frame is a rotation, oscillation, or sample scan of a scanning mirror. The time delay between frames can be significant in time-sensitive situations, such as collision avoidance in autonomous vehicles, where near-instantaneous velocity information is highly desirable. While other technologies, such as frequency-modulated continuous wave (FMCW) lidar, can measure velocity directly via the Doppler effect, they often have their own complexities and costs. Fig. 4 is a diagram of an embodiment of a Lidar system 400 configured for fast velocity measurement using two angularly separated laser arrays. A probe laser is positioned a few degrees away from a main laser for single-frame velocity sensing. The lidar system 400 comprises a first laser 404-1 and a second laser 404-2. The first laser 404-1 can be part of a first laser array (e.g., a column of lasers extending into and out of the sheet). The second laser 404-2 can be part of a second laser array (e.g., a column of lasers extending into and out of the sheet). In some configurations, the first laser 404-1 in Fig. 4 is the same laser as the first laser 204 in Fig. 2, and the second laser 404-2 in Fig. 4 is part of the first laser array described in Fig. 2 and in a different column than the first laser 204 (e.g., a laser above or below laser 204 and / or one or more columns of lasers above or below laser 204). A similar configuration could be used for the second laser 208 in Fig. 2 (e.g. a second laser to the left or right of laser 208 or with several columns of lasers to the left or right of laser 208).The first laser 404-1 is separated from the second laser 404-2 by a distance d. A first detector 408-1 and a second detector 408-2 are used to detect light reflected from an object in the field of view. The detectors 408 can be part of a one-dimensional or two-dimensional detector array. The detectors 408 can calculate distances from the lidar system 400 to one or more objects in the field of view. By knowing direction and distance information, the lidar system 400 can calculate the position of an object in its environment (e.g., relative to the lidar system). The Lidar system 400 uses two lasers (or two vertical rows of illumination) that are physically separated by a distance d, which corresponds to a slight angular separation theta θ (e.g. between 1 and 15 degrees, 1 and 10 degrees or 2 and 6 degrees, such as 4 degrees plus or minus 1, 2 or 3 degrees) in the FOV. By scanning the laser beams across the scene, the scanning mirror 212 effectively captures two images of the same object, separated by a very short, known time interval. A processing unit can then calculate the object's velocity in one or more dimensions by analyzing the change in the object's distance and / or position between these closely adjacent measurements. This intra-frame velocity calculation is significantly faster than traditional inter-frame methods and provides time-sensitive data for real-time applications. Although two sub-images can be calculated, the sub-images do not need to be two-dimensional (which would be a three-dimensional image / point cloud with distance information obtained via time-of-flight). In some configurations, one-dimensional images (i.e., scanning in one dimension) are used. In some configurations, only two points are used.For example, a first point is a reflection from the first laser off an object 80 meters directly in front of the Lidar System 400, and a reflection from the second laser is off an object 60 meters in the same direction in front of the Lidar System 400. These two points can be used to determine the velocity (of the object and / or the Lidar System) directly in front of the Lidar System 400 (e.g., a vehicle) for collision avoidance. In some situations, one-dimensional and / or two-dimensional sub-images can provide additional information about the object's motion. For example, an object moving parallel, perpendicular, or obliquely (not just head-on) to the Lidar System 400 can be tracked, and its position and velocity can be calculated. A first lens 412-1 is used to shape a beam from the first laser 404-1, from the second laser 404-2, or from both (in some embodiments, the second laser 404-2 has its own lens). The lasers 404 can be part of two vertical arrays of lasers, or two individual lasers whose beams are shaped into vertical lines by non-cylindrical optics. In some embodiments, each column of lasers shares one lens. In some embodiments, several columns of lasers share one lens. A second lens 412-2 is used to shape light reflected from the object onto the first detector 408-1, the second detector 408-2, or both (in some embodiments, the second detector 408-2 has its own lens). The lens 412 can be a simple lens or comprise an optical train. In some embodiments, each column of detectors shares one lens. In some embodiments, several columns of detectors share one lens. By swiveling light from the lasers 404 (or lines from two columns of lasers) across the field of view, the swivel mirror 212 generates two distinct data points (or two images, if combined with data from other light sources to create a point cloud image) from the detectors. Due to the angular separation θ, the second laser 404-2 illuminates a given point in the scene a short time t after the first laser 404-1. This time delay t is a function of the angular separation θ and the angular velocity ω of the scanning mirror, which is given by a function such as t = θ / (2ω), or t = θ / ω (e.g., for a rotating mirror). The processing unit analyzes a radial distance r, measured for corresponding pixels in the two images. The change in radial distance, Δr, over the known time interval t allows a direct calculation of the object's radial velocity (Vr = Δr / t). By using recognition software to identify objects in the point cloud, the system can analyze the change in the object's position in three dimensions (e.g., r, theta, and phi; or x, y, and z) between the two sub-frame images to calculate the complete 3D velocity vector. Because the time interval t is much shorter than the time required to acquire two complete frames, this method provides velocity information much faster than conventional ToF lidar. The data and / or images from the detectors 408 are acquired during the same movement (e.g., oscillation or rotation) of the scanning mirror 212. In other words, the light from both the first laser 404-1 and the second laser 404-2 strikes the same mirror while the mirror is rotating in one direction and before it changes direction; and light is detected by the first detector 408-1 and the second detector 408-2 while rotating in the same direction (e.g., reflections and before the mirror changes direction). Fig. 5 is a graph showing the relationship between the angular separation of the laser arrays, distance measurement accuracy and minimum resolvable velocity for the example lidar system shown in Fig. 4. Fig. 5 shows some design interrelationships for this system. A larger separation angle θ results in a longer time interval t, which allows for more accurate measurement of slowly moving objects. However, a larger angle may require more complex optics and a larger slew angle to ensure that the two images fully overlap. The accuracy of the velocity measurement may depend on the accuracy of the underlying distance measurements. Theta was chosen to be between 1 and 15 degrees, and in some configurations close to 4 degrees, because if an object is moving slowly, its speed might not be calculated correctly for a low theta (e.g., less than one degree). Conversely, a high theta might cause an object moving very fast, like a car, to be missed. Furthermore, a high theta can also reduce the effective field of view. For example, if theta is 15 degrees and the field of view is 90 degrees, the effective field of view would be 75 degrees. An angular separation (theta) of around 4 degrees can provide a balance between these conflicting factors. In some embodiments, more than two lasers 404 (more than two columns or more than two arrays of lasers) are used. For example, three arrays of lasers are used to obtain three velocity measurements. In this example, there could be a 4-degree theta between the lines of a first laser array and a second laser array, a 4-degree theta between the lines of the second laser array and a third laser array, and an 8-degree theta between the lines of the first laser array and the third laser array. Velocity measurements could be made from the differences between the first and second laser array lines, the second and third laser array lines, and the first and third laser array lines (to detect slower motion). In some embodiments, velocity measurements at the edges could be neglected (e.g.,Speed ​​measurements taken with the first laser in one direction could be neglected, and speed measurements taken with the third laser in the other direction could be neglected. In this way, the effective field of view could still be the total FOV minus theta (instead of total minus 2 theta). This would neglect the detection of low velocities at the edges of the field of view, which may be acceptable in some situations. While Fig. 4 shows a back-and-forth scanning mirror, this could also be replaced by a rotating polygonal mirror. The mirror could also pivot in the vertical direction, in which case the laser arrays would be arranged to generate horizontal illumination lines. In some cases, the two laser arrays and the detection system can have symmetrical functionality, so that when a back-and-forth mirror changes direction, the laser array and detector array that produced the first image then produce the second image. In some cases, the two arrays can be optimized for slightly different functionality. For example, the first laser or detector array can be optimized for low power, while the second laser or detector array is optimized for high accuracy. The two laser arrays can also be used for additional functionality, such as using the first laser array to measure the reflectivity of an object, so that the power of the second laser array can be adjusted to avoid saturating the detector for bright objects such as back-reflecting signs. Next, reference is made to Fig. 6, a flowchart of an embodiment of a lidar method 600 for detecting near and distant objects. The method 600 begins at step 604 with the emission of a first laser pulse within a first field of view and the emission of a second laser pulse within a second field of view (e.g., as described in Fig. 2 and Fig. 3). The first laser pulse is characterized by a first wavelength, and the second laser pulse is characterized by a second wavelength. In some configurations, the emission of the second laser pulse is performed simultaneously with the emission of the first laser pulse. In some configurations, the emission of the second laser pulse is performed within 0.00001, 0.001, 0.01, 0.1, or 0.25 seconds after the emission of the first laser pulse. In step 608, light reflected from the first and second fields of view is received (e.g., by the swiveling mirror in Fig. 2) and separated (e.g., by beam splitter 220 in Fig. 2). The received light is split into a first optical path corresponding to the first wavelength and a second optical path corresponding to the second wavelength. In step 612, light of a first wavelength and light of a second wavelength are detected. A first detector (e.g., detector 228 in Fig. 2) located in the first optical path detects reflected light of the first wavelength. A second detector (e.g., detector 232 in Fig. 2) located in the second optical path detects reflected light of the second wavelength. In step 616, a first distance to a first object in the first field of view is calculated based on the first detector, which detects reflected light corresponding to the first wavelength. In step 616, a second distance to a second object in the second field of view is calculated based on the second detector, which detects reflected light corresponding to the second wavelength. In some configurations, the second distance is more than 150, 200, 250, 300, 350, or 400 meters greater than the first distance. In some configurations, the method involves passing light of the first wavelength through a first lens with a first focal length, wherein the first lens is in the first optical path, and / or passing light of the second wavelength through a second lens with a second focal length, wherein the second lens is in the second optical path. Next, reference is made to Fig. 7, a flowchart of an embodiment of method 700 for lidar for measuring distance using a lidar system. Method 700 begins at step 704 with the emission of a first laser pulse into a first field of view and a second laser pulse into a second field of view (e.g., similar to step 604 in Fig. 6). In step 708, a first time-of-flight measurement is used to calculate a first distance to a first object in the first field of view, towards the detection, by means of a first detector (e.g. the detector 228 in Fig. 2), of a reflection of a first laser pulse from a first object in the first field of view. In step 712, the system waits with a predetermined time delay after the emission of the second laser pulse before detecting a reflection from the second laser pulse using a second detector (e.g., detector 232 in Fig. 2). A second time-of-flight measurement is calculated based on the reflection from the second laser pulse detected by the second detector. In step 716, a second distance to a second object in the second field of view is calculated based on the second time-of-flight measurement. The second area is farther away from the LiDAR system than the first area. In some configurations, the predetermined time delay corresponds to the round-trip travel time of light to a minimum distance of the second field of view; the minimum distance of the second field of view is equal to or greater than 250 meters; and / or the first field of view and the second field of view overlap at least partially. Next, reference is made to Fig. 8, a flowchart of an embodiment of Method 800 for lidar for measuring the velocity of an object using lidar. Method 800 begins at step 804 with the emission of light from a first laser and the emission of light from a second laser. The emission of light from the first laser is configured to produce a first illumination line. The emission of light from the second laser is configured to produce a second illumination line. The second illumination line is angularly separated from the first illumination line by a known angle. In some configurations, an illumination line is formed by a laser that emits light pulses (e.g., in rapid succession). In step 808, a swiveling mirror is used to swivel the first and second lighting lines across a field of view. An object in the field of view is illuminated by the second lighting line with a known time delay after it has been illuminated by the first lighting line. In step 812, reflections from an object in the field of view, caused by the first and second illumination lines, are detected by two or more detectors. For example, a first sub-image (e.g., a first 3D image as a first point cloud) is generated by panning the first illumination line across the field of view and detecting reflections from the object, and a second sub-image (e.g., a second 3D image as a second point cloud) is generated by panning the second illumination line across the field of view and detecting reflections from the object. In step 816, a first distance to the object and / or position of the object is calculated from detected reflections from the first illumination line, and a second distance to the object and / or position of the object is calculated from detected reflections from the second illumination line. In step 820, the speed of the object is calculated based on a difference between the first distance, the second distance and the known time delay, or between the first position, the second position and the known time delay (e.g., as discussed with reference to Fig. 4 and Fig. 5). In some configurations, the procedure also includes calculating a three-dimensional velocity vector by analyzing a change in the object's position between a first sub-image generated from first reflection data and a second sub-image generated from second reflection data. The various features described herein include, in particular, the following embodiments: 1. A system for detecting the velocity of an object using lidar, comprising: a first laser configured to generate a first illumination line in a field of view; a second laser configured to generate a second illumination line in the field of view, wherein the second illumination line differs angularly from the first illumination line by a known angle; and the known angle is between 1 and 15 degrees; a scanning mirror configured to pivot the first and the second illumination lines across the field of view; wherein: an object in the field of view is illuminated by the second illumination line with a known time delay,after it has been illuminated by the first illumination line; the known time delay is a function of the known angle and angular velocity of the scanning mirror; a first detector is configured to detect a first reflection of the first laser from the object; a second detector is configured to detect a second reflection of the second laser from the object; and a processing unit configured to: generate a first sub-image of the object based on data acquired from reflections of the first laser, including the acquisition of the first reflection, wherein the first sub-image is a first point cloud; generate a second sub-image of the object based on data acquired from reflections of the second laser, including the acquisition of the second reflection.wherein the second sub-image is a second point cloud; to calculate a three-dimensional velocity vector of the object by analyzing a change in the object's position between the first sub-image and the second sub-image and the known time delay. 2. System of embodiment 1, wherein the first laser is part of a first laser array and the second laser is part of a second laser array; and the first laser array and the second laser array share a focusing lens. 3. System of embodiment 1 or 2, wherein the first laser array, the second laser array, the first detector, the second detector, and the processing unit are located on the same chip. 4. System of embodiments 1 to 3, wherein the scanning mirror is a oscillating mirror or a rotating polygon mirror. 5. System for detecting the velocity of an object using lidar, in particular in combination with one of embodiments 1 to 4.The system comprises: a first laser configured to generate a first illumination line in a field of view; a second laser configured to generate a second illumination line in the field of view, the second illumination line being angularly spaced from the first illumination line by a known angle; a scanning mirror configured to pivot the first and second illumination lines across the field of view, wherein: an object in the field of view is illuminated by the second illumination line with a known time delay after illumination by the first illumination line; the known time delay is based on the known angle; a first detector is configured to detect a first reflection of the first laser from the object; a second detector is configured to detect a second reflection of the second laser from the object; and a processing unit,which is configured to: calculate a first position of the object based on the detection of the first reflection; calculate a second position of the object based on the detection of the second reflection; and calculate a velocity of the object based on a difference between the first position and the second position and the known time delay. 6. System of embodiment 5, wherein the known angle is between 1 and 15 degrees. 7. System of embodiment 5 or 6, wherein the known time delay is a function of the known angle and an angular velocity of the swivel mirror. 8. System of embodiments 5 to 7, wherein the processing unit is further configured to calculate a three-dimensional velocity vector of the object by analyzing a change in the object's position between a first sub-image generated from data with the first reflection and a second,sub-image generated from data with the second reflection. 9. System of embodiments 5 to 8, wherein the first laser is part of a first laser array and the second laser is part of a second laser array. 10. System of embodiment 9, wherein the first laser array and the second laser array share a focusing lens. 11. System of embodiment 9 or 10, wherein the first laser array, the second laser array, the first detector, the second detector, and the processing unit are located on the same chip. 12. System of embodiments 5 to 11, wherein the scanning mirror is a oscillating mirror or a rotating polygon mirror. 13. Method for detecting the velocity of an object using lidar, in particular in combination with embodiments 1 to 12, comprising: emitting light from a first laser configured to generate a first illumination line; emitting light from a second laser,which is configured to generate a second illumination line; wherein the second illumination line is angularly separated from the first illumination line by a known angle; pivoting the first and second illumination lines by means of a scanning mirror over a field of view, wherein an object in the field of view is illuminated by the second illumination line for a known time delay after illumination by the first illumination line; detecting, by means of at least one detector array, reflections of the first and second illumination lines from the object; calculating a first position of the object based on the reflection of the first illumination line; calculating a second position of the object based on the reflection of the second illumination line; and calculating a velocity of the object based on a difference between the first position,the second position and the known time delay. 14. Method of embodiment 13, wherein the known angle is between 1 and 15 degrees. 15. Method of embodiment 13 or 14, wherein the known time delay is a function of the known angle and the angular velocity of the scanning mirror. 16. Method of embodiments 13 to 15, further comprising calculating a three-dimensional velocity vector of the object by analyzing a change in the object's position between a first sub-image generated from first reflection data and a second sub-image generated from second reflection data. 17. Method of embodiments 13 to 16, wherein the first laser is part of a first laser array and the second laser is part of a second laser array. 18. Method of embodiment 17, wherein the first laser array and the second laser array share a focusing lens. 19. Method of embodiment 17 or 18,wherein the first laser array, the second laser array, the first detector, the second detector, and the processing unit are located on the same chip. 20. Method of embodiments 13 to 19, wherein the scanning mirror is a oscillating mirror or a rotating polygon mirror. 21. Lidar system, in particular in combination with embodiments 1 to 20, the system comprising: a first laser source configured to emit light at a first wavelength; a second laser source configured to emit light at a second wavelength different from the first wavelength; a scanning mirror configured to: pan light from the first laser source over a first field of view; pan light from the second laser source over a second field of view; and receive light reflected from the first and second fields of view; a beam splitter configured toto receive the reflected light from the scanning mirror; wherein the beam splitter is configured to separate the reflected light into a first optical path corresponding to the first wavelength and a second optical path corresponding to the second wavelength; a detector arranged in the first optical path for detecting reflected light of the first wavelength; and a detector arranged in the second optical path for detecting reflected light of the second wavelength. 22. System of embodiment 21, further comprising: a first lens with a first focal length in the first optical path; and a second lens with a second focal length in the second optical path, wherein the second focal length is longer than the first focal length. 23. System of embodiment 21 or 22, wherein: the first optical path is optimized for a first detection range,and a first field of view; and the second optical path is optimized for a second detection area and a second field of view; wherein: the second detection area is longer than the first detection area, and the second field of view is narrower than the first field of view. 24. System of embodiment 23, wherein the first wavelength and the second wavelength are between 850 nm and 960 nm. 25. System of embodiment 24, wherein the first wavelength is 905 nm plus or minus 10 nm, and the second wavelength is 940 nm plus or minus 10 nm. 26. System of embodiments 21 to 25, further comprising a processing unit configured to generate a three-dimensional point cloud by combining data from at least the first detector and the second detector. 27. Lidar method for detecting near and distant objects, in particular in combination with embodiments 1 to 26.The method comprises: emitting a first laser pulse into a first field of view, wherein the first laser pulse is characterized by a first wavelength; emitting a second laser pulse into a second field of view, wherein the second laser pulse is characterized by a second peak wavelength; receiving reflected light from the first and second fields of view; splitting the reflected light into a first optical path corresponding to the first wavelength and a second optical path corresponding to the second wavelength; detecting, by means of a first detector arranged in the first optical path, reflected light of the first wavelength; detecting, by means of a second detector arranged in the second optical path, reflected light of the second wavelength; calculating a first distance to a first object in the first field of view based on the light detected by the first detector.28. Method according to embodiment 27, further comprising: guiding light of the first wavelength through a first lens with a first focal length, wherein the first lens is located in the first optical path; and guiding light of the second wavelength through a second lens with a second focal length, wherein the second lens is located in the second optical path. 29. Method for lidar for measuring distances using a lidar system, in particular in combination with embodiments 1 to 28.The method comprising: emitting a first laser pulse into a field of view; emitting a second laser pulse into a second field of view; upon detecting a reflection from the first laser pulse from a first detector, initiating a first time-of-flight measurement to calculate a first distance to a first object in the first field of view; waiting a predetermined delay period after the emission of the second laser pulse before detecting a reflection from the second laser pulse; initiating a second time-of-flight measurement based on the reflection from the second laser pulse; and calculating a second distance to a second object in the second field of view based on the second time-of-flight measurement, wherein the second area is located farther away from the LIDAR system than the first area. 30. Method according to embodiment 29,wherein the predetermined time delay corresponds to the round-trip travel time of light to a minimum distance in the second field of view. 31. Method according to embodiment 30, wherein the minimum distance of the second area is equal to or greater than 250 meters. 32. Method according to any one of embodiments 29 to 31, wherein the first field of view and the second field of view are at least partially overlapping. Various features described herein, such as methods, devices, computer-readable media, and the like, can be realized by a combination of designated components, programmable processors, and / or programmable devices. Some processes described herein can be implemented by the same processor or by different processors. Where certain components are described as configured to perform certain operations, such configuration can be achieved, for example, by designing electronic circuits to perform the operation, by programming programmable electronic circuits (such as microprocessors) to perform the operation, or a combination thereof.Furthermore, while the embodiments described above relate to specific hardware and software components, experts will recognize that different combinations of hardware and / or software components can also be used, and that certain operations described as being implemented in hardware may be implemented in software, and vice versa. The above description provides details to aid in understanding the embodiments. However, it should be understood that the embodiments can be implemented without some of these specific details. In some cases, well-known circuits, methods, algorithms, structures, and technologies are not shown in the drawings. While the principles of the disclosure have been described above in connection with specific devices and methods, it should be understood that this description is merely exemplary and not intended to limit the scope of the disclosure. Embodiments have been selected and described to illustrate the principles and practical applications, enabling other skilled persons to use the disclosure in various embodiments and with various modifications, depending on their suitability for a particular intended use. It will be understood that the description is intended to cover modifications and equivalents. Furthermore, it should be noted that the implementations can be described as a process, which can be represented as a flowchart, flow diagram, data flow diagram, structure diagram, or block diagram. Although a flowchart can describe the operations as a sequential process, many of the operations can occur in parallel or simultaneously. Moreover, the sequence of operations can be rearranged. A process is complete when its operations are finished, but it may have additional steps that are not included in the diagram. A process can correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. The use of "a", "an", or "the" is to be understood as "one or more" unless otherwise stated. Patents, patent applications, publications, and descriptions mentioned herein are fully incorporated by reference for all purposes. None of them are acknowledged as prior art. The specific details of particular embodiments can be combined in any suitable way without deviating from the concept and scope of the embodiments of the invention. However, other embodiments of the invention may be directed to specific embodiments that address each of the individual aspects or specific combinations of these individual aspects. The above description of embodiments of the disclosure is presented for illustrative and descriptive purposes. It is not intended to be exhaustive or to limit the disclosure to the exact form described, and many modifications and variations are possible in light of the above teaching. The embodiments were selected and described to explain the principles and practical applications of the invention, enabling other skilled persons to use the invention in various embodiments and with various modifications, depending on their suitability for a particular intended use. QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature US 63 / 739,911

[0001] US 10,690,754

[0003] US 18 / 531,507

[0003] US 18 / 787,427

[0014] US 19 / 027,522

[0014] US 15 / 267,558

[0024] US 15 / 971,548

[0024] US 16 / 504,989

[0024] US 16 / 775,166

[0024] US 17 / 032,526

[0024] US 17 / 133,355

[0024] US 17 / 205,792

[0024]

Claims

A system for detecting the velocity of an object using lidar, comprising: a first laser configured to generate a first illumination line in a field of view; a second laser configured to generate a second illumination line in the field of view, wherein the second illumination line differs angularly from the first illumination line by a known angle; a scanning mirror configured to pivot the first and the second illumination lines across the field of view; wherein an object in the field of view is illuminated by the second illumination line with a known time delay after it has been illuminated by the first illumination line; wherein the known time delay is based on the known angle; wherein a first detector is configured to detect a first reflection of the first laser from the object;wherein a second detector is configured to detect a second reflection of the second laser from the object; and a processing unit configured to calculate a first position of the object based on the detection of the first reflection; to calculate a second position of the object based on the detection of the second reflection; and to calculate the velocity of the object based on a difference between the first position, the second position, and the known time delay. System according to claim 1, wherein the known angle is between 1 and 15 degrees. System according to claim 1 or 2, wherein the known time delay is a function of the known angle and angular velocity of the scanning mirror. System according to one of claims 1 to 3, wherein the processing unit is further configured to calculate a three-dimensional velocity vector by analyzing a change in the position of the object between a first sub-image generated from data of the first reflection and a second sub-image generated from data of the second reflection. System according to one of claims 1 to 4, wherein the first laser is part of a first laser array and the second laser is part of a second laser array. System according to claim 5, wherein the first laser array and the second laser array share a focusing lens. System according to claim 5 or 6, wherein the first laser array, the second laser array, the first detector, the second detector and the processing unit are located on the same chip. System according to any one of claims 1 to 7, wherein the scanning mirror is an oscillating mirror or a rotating polygonal mirror. A method for detecting the velocity of an object using lidar, comprising: emitting light from a first laser configured to generate a first illumination line; emitting light from a second laser configured to generate a second illumination line, wherein the second illumination line is angularly separated from the first illumination line by a known angle; panning the first and second illumination lines over a field of view by means of a scanning mirror, wherein an object in the field of view is illuminated by the second illumination line for a known time delay after illumination by the first illumination line; detecting, by means of at least one detector array, reflections of the first and second illumination lines from the object; and calculating a first position of the object based on the reflection of the first illumination line.Calculating a second position of the object based on the reflection of the second illumination line; and calculating a velocity of the object based on a difference between the first position, the second position, and the known time delay. Method according to claim 9, wherein the known angle is between 1 and 15 degrees. Method according to claim 9 or 10, wherein the known time delay is a function of the known angle and angular velocity of the scanning mirror. Method according to one of claims 9 to 11, wherein the processing unit is further configured to calculate a three-dimensional velocity vector by analyzing a change in the position of the object between a first sub-image generated from data of the first reflection and a second sub-image generated from data of the second reflection. Method according to any one of claims 9 to 12, wherein the first laser is part of a first laser array and the second laser is part of a second laser array. Method according to claim 13, wherein the first laser array and the second laser array share a focusing lens. Method according to claim 13, wherein the first laser array, the second laser array, the first detector, the second detector and the processing unit are located on the same chip.

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