Illumination pattern system and associated methods for 3D runtime systems

Abstract

Lighting system (212) which features: a light source (214) located at a proximal end of a volume and configured to emit a photon beam; and a diffuser (216) arranged to receive the photon beam and disperse the photon beam into an output beam extending from a distal end plane of the volume to an interspace plane (220) in the volume in order to define an illumination volume (218), wherein the output beam has an illumination intensity that generates an irradiance threshold at a transverse and off-axis region of the distal end plane, wherein the diffuser (216) is further configured to maintain the irradiance at a transverse and off-axis region of the interspace plane (220) at, or above, the irradiance threshold at the transverse and off-axis region of the distal end plane. wherein the output beam has an illumination intensity that produces a first irradiance profile at the distal end plane and a second irradiance profile at the interspace plane (220), wherein the diffuser (216) is configured such that the first irradiance profile varies over the distal end plane and that the second irradiance profile varies over the interspace plane (220), wherein the diffuser (216) is configured such that the illumination intensity of the output beam satisfies the following condition: I(Θ) ≤ I max (Θ) = I0cos(Θ), where Θ is an angle to an illumination axis of the output beam, and I0 is an illumination intensity on the illumination axis, wherein the diffuser (216) is configured such that the illumination intensity I of the output beam, expressed as I x (Θ)×I y (Θ), the following condition is met: lx ( θ x ) ≥ l x_min ( θ x ) = lx ( θ x 0 ) cos ( θ x 0 ) sin ( θ x 0 ) 2 cos ( θ x ) sin ( θ x ) 2 where Θ x0 an angle to an illumination axis of the output beam, measured at the distal end plane along an x-axis, and Θ x an angle relative to an illumination axis of the output beam along the x-axis; and the following holds true: ly ( θ y ) ≥ ly _ min ( θ y ) = ly ( θ y 0 ) cos ( θ y 0 ) sin ( θ y 0 ) 2 cos ( θ y ) sin ( θ y ) 2 , where Θ y0 an angle to an illumination axis of the output beam, measured at the distal end plane along a y-axis, and Θ y an angle to an illumination axis of the output beam along the y-axis.

Description

Background of the invention

[0001] Three-dimensional (3D) sensors are used to measure loads inside trailers and shipping containers. For example, 3D sensors measure distances from the rear wall of a trailer / container to the nearest wall inside that trailer / container. From these distances, users can determine metrics such as the available storage space within a volume.

[0002] Today's 3D sensors are structured light (SL) sensors used in trailer monitoring units (TMUs) mounted on semi-trailers. With SL sensors, a projector projects an image into a volume (the trailer / container), multiple cameras capture images of the projected image, and these images are then processed to determine relative distances to the rear wall and objects within the volume. This process requires complex and time-consuming image processing, and the results are often inaccurate. In particular, SL sensors are highly dependent on the light intensity within a volume, or when objects of different shapes or dimensions are arranged within that volume. Consequently, conventional 3D sensors have limited effectiveness in "smart" shipping applications where precise assessment of trailer loads is required.

[0003] US 2010 / 0177164A1 describes a system and method for use in object reconstruction. The system comprises an illumination unit and an imaging unit. The illumination unit includes a coherent light source and a random speckle pattern generator positioned in the optical path of the illumination light traveling from the light source to an object, thereby projecting a coherent random speckle pattern onto the object. The imaging unit is configured to detect a light response from an illuminated area and to generate image data. The image data points to the object with the projected speckle pattern and is thus indicative of a shift of the pattern in the image of the object relative to a reference image of the pattern. This enables the real-time reconstruction of a three-dimensional map of the object.

[0004] US 5 598 280 A describes a film lens with a translucent base having one side and an opposite side, a plurality of concave or convex unit lenses formed on one side of the translucent base, and a plurality of protrusions formed on the opposite side of the translucent base, having a profile height not less than the wavelength of a source light and not greater than 100 µm.

[0005] US 2011 / 0043768A1 describes an image display device comprising: a laser light source for emitting a laser beam; an optical scattering element for scattering the laser beam; a drive unit for oscillating the optical scattering element; and an image conversion unit for converting the laser beam emitted by the optical scattering element into an image. The optical scattering element, arranged in the drive unit, is set into oscillation and operated in a state in which a drive amplitude of the drive unit, which is, for example, an amplitude driven in a direction X in a plane perpendicular to an optical axis, is not constant.

[0006] WO 2017 / 087 244 A1 describes a method and a device for receiving a depth image from a depth sensor directed at an open end of a shipping container, wherein the depth image comprises a plurality of grid elements, each having a corresponding depth value, for identifying one or more occlusions in the depth image, for correcting the one or more occlusions in the depth image using one or more temporally adjacent depth images, and for outputting the corrected depth image for filling estimation.

[0007] Therefore, there is a need for a system for illuminating a volume with a lighting pattern that maintains sufficient illuminance within the volume while maintaining a maximum illuminance that provides safe working conditions for personnel within the volume. Brief description of the multiple views of the drawings

[0008] The accompanying figures, in which identical reference numerals denote identical or functionally equivalent elements in the separate views, are included in the application together with the description below and form part of it, and serve to further explain embodiments of concepts which include the claimed invention and illustrate various principles and advantages of these embodiments. Fig. Figure 1 is a schematic representation of a state-of-the-art lighting system. The Fig. 2A and Fig. Figure 2B shows examples of schematic representations of a top or side view of a vehicle trailer with an exemplary lighting system that produces an exemplary lighting pattern, according to some embodiments. Fig. Figure 3 is a schematic representation of an exemplary lighting system according to some embodiments. Fig. Figure 4 is a representation of an example of a lighting pattern criterion according to some embodiments. The Fig. 5A and Fig. 5B are further examples of lighting pattern criteria, with different form factors, according to some embodiments. Fig. Section 6 explains another example of a vehicle trailer with a lighting system similar to that of Fig. 3, used for time-of-flight measurement applications, according to some embodiments.

[0009] Experts in this field will recognize that elements in the figures are shown for simplification and clarity and are not necessarily to scale. For example, the dimensions of some elements in the figures may be enlarged relative to other elements to help improve the understanding of embodiments of the present invention.

[0010] The components of the apparatus and the method have been represented, where appropriate, by conventional symbols in the drawings, showing only those specific details which relate to the understanding of the embodiments of the present invention, in order not to burden the disclosure with details which will be readily apparent to those skilled in the art in this field with knowledge of the present description. Detailed description of the invention

[0011] According to the invention, a lighting system with the features of claim 1 and a lighting system with the features of claim 2 are provided. Likewise, according to the invention, a method with the features of claim 4, a method with the features of claim 5, and a method with the features of claim 6 are provided. Exemplary embodiments are described in the dependent claims, the following description, and the figures.

[0012] As described herein, the embodiments of the present disclosure relate to techniques for illuminating a volume with an illumination pattern that maintains illuminance levels sufficient to provide on-axis and off-axis illumination of objects within a volume, for example, a vehicle trailer or a shipping container.

[0013] In some implementations, a lighting system includes a light source located at the proximal end of a volume, and the lighting system is configured to emit an output beam into the volume. The volume may be a shipping container, such as a vehicle trailer, a shipping container, or any other volume within which multiple objects can be arranged for shipping. The lighting system may further include a diffuser positioned to receive the output beam from the lighting system. The diffuser can disperse the output beam so that it extends from a distal end plane of the volume to an interspace plane within the volume, such as a plane of the nearest object in the volume.Furthermore, the diffuser can be configured such that the output beam has a threshold illuminance, such that the illuminance at a transverse and off-axis region of the distal end plane is above a threshold value. The diffuser can also be configured such that the output beam's illuminance at a transverse and off-axis region of the interspace plane is at or exceeds this threshold value. The result is the illumination of a volume, also referred to here as an illumination volume, which satisfies a condition for a minimum illuminance threshold throughout the entire depth and transverse region of this illumination volume.

[0014] In various embodiments, a system for monitoring a volume is provided. The system may include a processor, memory, an optical sensor, and an illumination system as described, all located at a proximal end of the volume. In some embodiments, the light source is an infrared light source, and the optical sensor is an infrared sensor. In some embodiments, the processor controls the optical sensor to measure infrared radiation reflected by an object within the volume. In various embodiments, the processor can determine distances to objects within the volume from the measured infrared radiation. In various embodiments, the processor can control the illumination intensity of the light source based on the measured infrared radiation.In some embodiments, the system is a time-of-flight system that measures distances to objects in the volume using a time-of-flight measurement.

[0015] Fig. Figure 1 is a schematic representation of a conventional illumination system 100, as used by 3D sensors, such as those used in video game environments. A light source 101, usually a laser light source, produces an output beam 102, while a diffuser 104 receives this output beam and converts it into an influenced output beam 102', which uniformly spreads the beam over a solid angular volume 106, thereby creating a uniform irradiance across a flat screen 108. Such a conventional configuration is suitable for gaming applications, which are short-range applications. The uniform irradiance at the screen 108 is important for optimizing the detection of an object within the solid angular volume 106. For example, if a game console is moved somewhere within the volume, the 3D sensor can detect the game console with the same accuracy.This uniformity is partly achievable because, over the short distances in gaming applications, e.g. 5 m or less, the 3D sensor can work efficiently without the use of high-intensity light.

[0016] Unfortunately, configurations like those in Fig. 1. Not suitable for applications involving large volumes, e.g., volumes extending more than 5 m from the light source, and certainly not where personnel are working within the volume. The light intensity required to maintain uniform illuminance on the flat screen would exceed established safety limits for laser output illuminance when extended over a large volume.

[0017] The Fig. 2A and Fig. Figure 2B shows a schematic representation of a lighting system environment 200 according to various exemplary embodiments. Fig. 2A shows a top view of the lighting system environment 200, and Fig. Figure 2B shows a side view.

[0018] Environment 200 can be implemented in a shipping application for vehicles with trailers, as shown. In the example shown, environment 200 contains a vehicle trailer 202, which has a distal end 204, closest to a vehicle cab 206, and a proximal end 208, where personnel typically enter the trailer 202 by loading or unloading objects during shipping or unloading, respectively.

[0019] To load the vehicle trailer 202, personnel typically access the proximal end 208 and transport objects onto the floor of the vehicle trailer 202, for example, using a forklift or other container carrier. In some examples, autonomous vehicles can be used to transport objects into the vehicle trailer 202. Initially, objects are usually loaded against a rear wall (at a distal end plane) 210 of the trailer 202, and objects are then loaded until the rear wall 210 is partially or completely covered by objects. Objects continue to be arranged in the vehicle trailer 202 until a shipping volume within the vehicle trailer 202 is completed.

[0020] For applications such as measurements with 3D sensors, to ensure adequate illumination of the shipping volume within the trailer 202 of the vehicle, the environment 200 further includes a lighting system 212 located at the proximal end 208. The lighting system 212 comprises a light source 214 that generates an output beam intended to penetrate the volume of the vehicle trailer 202. The light source 214 can include one or more laser light sources, one or more light-emitting diodes (LEDs), a combination thereof, or another suitable light source. Furthermore, a diffuser 216 is included in the lighting system 212 and is positioned to receive and diffuse an output beam from the light source 214, as shown in the examples provided.

[0021] The lighting system 212, with the combination of light source 214 and diffuser 216, is configured to illuminate a lighting volume 218 within the vehicle trailer 202, this lighting volume 218 extending from the rear wall 210 to an intermediate plane 220 located between the distal end 204 and the proximal end 208. The intermediate plane 220 is defined by points “A” and “C” in Fig. 2A or 2B are marked, where point “A” indicates a transversely axially distant area of ​​the interspace plane 220, from an x-axis 222 of the illumination, indicated by an axially distant angle Θ. x . Point “C” indicates another transversely off-axis area of ​​the interspace plane 220, from a y-axis 224 of the illumination, indicated by an off-axis angle Θ. y. Similarly, on the rear wall 210, a transversely off-axis area is indicated by point “A0”, measured from the x-axis 222 of the lighting, and a transversely off-axis area is indicated by point “C0”, measured from the y-axis 224 of the lighting.

[0022] In the example shown, the lighting system 212 is configured to provide an output beam with an illumination intensity pattern that illuminates the volume 218, wherein this illumination pattern meets certain pattern criteria, and wherein the criteria are based on the fact that a desired irradiance is to be obtained over an illumination volume extending from the rear wall 20 to the space plane 220.

[0023] In some embodiments, a first illuminance criterion is that the lighting system 212 should be configured to maximize the irradiance of the vehicle trailer 202, particularly at the rear wall 210 (maximum rear wall illuminance), while maintaining this illuminance (and therefore the illuminance from the light source) at predetermined safety levels, or below, for personnel. Various examples of safety levels can be used to define the maximum illuminance at the rear wall. An example of a safety level for a laser light source is that a maximum illuminance from the light source is present, as specified in the requirements for Class 1 lasers, defined by 21 Code of Federal Regulations 1040 (21 CFR 1040) in the USA., or as specified internationally by the International Electrotechnical Commission (EIC) under regulation EIC 60825. Each of these two can be seen as defining a maximum permissible available emission limit.

[0024] In some embodiments, a second illumination intensity criterion is to maintain an irradiance of an off-axis region of the interspace plane 220 (i.e., at points "A" and / or "C") at a minimum illuminance, or below, that is present at the rear wall. While other design criteria can be specified, it has been found that these two criteria provide sufficiently high illuminances at the rear wall 210 while maintaining a minimum useful irradiance over the entire illumination volume 218, including its entire depth and transverse area, so that the entire illumination volume 218 is sufficiently illuminated for time-of-flight measurements with 3D sensors.

[0025] Fig. Section 3 describes an exemplary implementation of a lighting system, such as lighting system 212, which is configured as a trailer monitoring unit to meet the lighting pattern criteria specified above. A lighting system 300 has a processor 302 and a memory 304 configured to perform each of the functions described herein. The lighting system 300 has a light source 306 and a diffuser 308 arranged to receive an output beam from the light source 306 and modify this beam to project the desired lighting pattern onto the trailer 202. In some embodiments, the processor 302 communicates with the light source 306 to control its operation.In some embodiments, the diffuser 308 can be a static element configured to produce a single desired illumination pattern. The diffuser 308 can, for example, be a thin-film or solid construction, flexible or rigid. In other embodiments, the diffuser 308 can be a dynamic element that can be modified to produce different illumination patterns under varying conditions. In some such embodiments, the diffuser 308 can be an electronically controlled element, such as an electronically controlled light-shaping diffuser available from Luminit in Torrance, CA, which communicates with the processor 302 to control which illumination pattern is produced by the diffuser 308.The lighting system 300 also features an optical sensor 310 which is in communication with the processor 302 to perform time-of-flight measurements and other functions, as described here.

[0026] In order to meet the illumination intensity criteria, the diffuser 308 is configured in various embodiments to produce an illumination intensity as described below.

[0027] The illuminance of the output beam from the lighting system 300 is denoted by I(Θ), where Θ is measured from a central axis (of the lighting system) where the illuminance is highest, and where the output beam produces the highest irradiance in every plane within the volume (i.e., where the lighting axis intersects this plane). In various embodiments, to determine the illuminance I max(Θ) of the output beam, and more precisely to maximize the illuminance at the rear wall 210 (see Fig. 2A and Fig. 2B) to maximize, within the limits for eye safety defined under Class 1, the diffuser 308 must be configured to meet the standard EIC EN60825-1:2014, where the achievable emission limit (AEL) is expressed in terms of radiant power within a detector with a diameter of 7 mm (maximum size of the eye pupil), at a distance of 100 mm from the diffuser surface (nearest distance for accommodation of the eye). AEL limits the radiation intensity I max (Power per solid angle) of the lighting source: lmax=AELπ3.5mm2100mm2

[0028] AEL is linearly proportional to the angular size of the laser spot on the diffuser, as seen from a distance of 100 mm. As the viewing angle Θ to the diffuser (between the eye's line of sight and the normal to the diffuser) increases, the angular spot size decreases. Therefore, AEL is a function of the viewing angle Θ to the diffuser. A conservative estimate from EIC EN60825-1:2014 was used, so that AEL was treated as proportional to the cosine of the angle Θ, resulting in a maximum illumination intensity, per angle, of the diffused output beam: lmax(θ)∝cos(θ)

[0029] This relationship contrasts with a conventional distribution, such as that of Fig. 1, in which the radiation intensity increases with the angle Θ to ensure a uniform irradiance at the distal plane.

[0030] Therefore, in some embodiments, the diffuser 308 maximizes the illumination intensity I(Θ) (and therefore the irradiance) at the rear wall 210, according to the following condition: l(θ)≤lmax(θ)=locos(θ) where I o The illumination intensity is on the axis, i.e., at Θ = 0. Expression (3) provides the illumination intensity that is to be maintained over a range of angles off-axis, be it in the x-direction (horizontal illumination intensity) or in the y-direction (vertical illumination intensity). In the x-direction example, and considering the irradiance at the back wall, i.e., I x (Θ) are the suitable angles, as in the Fig. 2A and Fig. 2B is defined such that -Θ holds. x0 < Θ x < Θ x0 and Θ y < 0. In the example for the y-direction, i.e., I y (Θ), the suitable angles are such that -Θ holds. y0 < Θy < Θ y0 Naturally, these expressions apply to every angle Θ, to light illuminating a volume, i.e., -Θ. xA < Θ x < Θ xA and Θ y < 0 for the interspace plane along the x-axis, and -Θ yC < Θ y < Θ yC for the interspace plane along the y-axis. The maximum permissible angles of Θ xA and Θ yC depend on the diffuser, and are known as Θ x_max and Θ y_max in the example shown. These maximum angles also determine the closest position of the interstitial plane to the proximal end; therefore, the maximum angles define the maximum size of the illuminated volume, measured from the back wall.

[0031] The diffuser 308 is still configured to produce an output beam with an illumination intensity criterion I min(Θ) generates an irradiance that minimizes the off-axis irradiance across the illumination volume. In some embodiments, this means that the irradiance at the space between the walls (also referred to as a load wall), on the sides and bottom of the vehicle trailer 202, should not fall below the irradiance at the rear wall 210. Therefore, a consistent minimum illuminance should be maintained, for example, across the entire illumination volume 218.

[0032] In other words, and as in supervision ( Fig. As shown in 2A), the irradiance at the off-axis region of the space plane 220, i.e. at point “A”, should be greater than or equal to the irradiance at the rear wall 210 at the corresponding off-axis region (point “A0”).

[0033] To determine the conditions for the diffuser 308 such that a minimum condition is met, the irradiance E is used. adefined at point "A". For the x-direction, the irradiance E is a as a function of the width W of the vehicle trailer, the angle Θ, and the source illumination intensity I(Θ) x ) expressed as follows: Ea(θx)=l(θx)cos(θx)[.5Wsin(θx)]2

[0034] E a should not be with angle Θ x lose weight. Therefore, E a express it as follows: Ea(θx)≥Ea(θx0),whereθx≥θx0=atan(.5WL) where L is the length of the rear wall to the diffuser, i.e. the length of the trailer of the vehicle.

[0035] From expression (5) we obtain the following expression (6) for the horizontal intensity, which the illumination pattern of the diffuser 308 must follow in different embodiments: lx(θx)≥lx_min(θx)=lx(θx0)cos(θx0)sin(θx0)2cos(θx)sin(θx)2

[0036] Accordingly, the side view of the vehicle trailer 202 ( Fig. 2B) the irradiance E c The irradiance at the lower end of the space plane 220 (at point “C”) must be greater than or equal to the irradiance at point “C0” on the rear wall. From this similar condition, a vertical intensity is determined which the illumination pattern of the diffuser 308 must follow, expressed in various embodiments as (7): ly(θy)≥ly_min(θy)=ly(θy0)cos(α)sin(α)2cos(α+θy)sin(α+θy)2 where α is the inclination of the lighting system mounted on a proximal end of a vehicle trailer, as exemplified in Fig. 2B shown.

[0037] These expressions (6) and (7) describe criteria for the minimum illuminance along horizontal and vertical planes, as provided by the diffuser, to achieve the desired irradiance over the illuminated volume. Corresponding expressions can be derived, if desired, for other irradiance conditions to ensure that the irradiance at or near the corners of the space plane 220 does not fall below the irradiance at or near the rear wall 210 of the trailer. This is helpful in ensuring proper illumination at these extreme values.

[0038] Fig. Figure 4 is a representation of an intensity tolerance range 400 for a horizontal illuminance of an output beam emitted into a trailer of a vehicle, as determined by the lighting system according to various embodiments. The tolerance range 400 is bounded at the upper end by a curve 402 of maximum illuminance and at the lower end by a curve 404 of minimum illuminance. In the example shown, curves 402 and 404 were determined from exemplary expressions (3) and (6). However, it should be noted that these expressions are only examples and that other expressions (or illuminance criteria) can be used to determine the maximum curve 402 and the minimum curve 404. Fig. While section 4 explains an acceptable range for horizontal illumination intensity, a corresponding profile would exist for vertical illumination intensity, except that in the illustrated example, the diffuser is positioned to produce an output beam at an angle relative to the longitudinal y-axis. Furthermore, the illustration concerns intensity, but an acceptable range for irradiance could also be defined, with a corresponding profile, except that it is a measure of irradiance as a function of the off-axis angle.

[0039] The Fig. 5A and Fig. Section 5B explains several examples of permissible intensity ranges, each determined by a design criterion factor, and each applicable to more general scenarios of some of the present embodiments. Fig. 5A explains permissible illuminance ranges for a horizontal illuminance of an output beam emitted into a vehicle trailer. Fig. 5B explains illuminance intensity tolerance ranges for the vertical illuminance of this output beam. Compared to expressions (6) and (7), the illuminance pattern criteria for the tolerance ranges in the Fig. 5A and Fig. 5B the following expressions: lx(θx,kx):=min[cos(θx),(cos(θx0)sin(θx0)2cos(θx)sin(θx)2)kx] ly(θy,ky):=if θy<0,cos(θy),min[cos(θy),(cos(α)sin(α)2cos(θy+α)sin(θy+α)2)ky]] l(θx,θy,kx,ky):=lx(θx,kx)ly(θy,ky) where the same definitions apply here as regarding the Fig. 2A and Fig. 2B can be used. In contrast to expressions (6) and (7), expressions (8) and (9) each depend on an additional design criterion, namely the form factor, expressed by kx for the form factor of the horizontal axis and by ky for the form factor of the vertical axis.

[0040] The form factor k is used to further define the resulting illumination intensity produced by a diffuser. The form factor can range from 0 to 1. If the form factor k = 1, the result is a minimum illumination intensity, as shown in the Fig. 5A and Fig. 5B shown. For example in Fig. In 5A, curve 602 of the smallest minimum intensity corresponds to a form factor of k = 1, whereas curve 604 of the largest maximum intensity corresponds to a form factor of 0. Therefore, expression (8) can singularly define the maximum and minimum conditions for horizontal illumination intensity due to the fact that they have different form factors. The same applies to expression (9) with respect to conditions for vertical illumination intensity. The form factor k is a variable that can be used to achieve a compromise between efficient illumination of a rear wall and uneven intensity across a space plane of the trailer.

[0041] In configurations where the diffuser is electronically controlled, a processor can be programmed to adjust the form factor to a desired value for the specific trailer to be illuminated. Variables of the trailer, such as length, width, and height, can be used by the processor to determine a desired form factor, which is then used to define a diffuser profile. The processor can then communicate the desired diffuser profile to the diffuser.

[0042] In Fig. 3. The lighting system 300 can be used for 3D sensor runtime measurements on a vehicle trailer, with an example relating to Fig.6 is described. These transit-time measurements can be used to identify objects within the vehicle trailer, to identify an interstitial plane corresponding to the nearest object in the vehicle trailer, to determine an occupied volume in the vehicle trailer, to determine an available volume in the vehicle trailer, to determine dimensions of objects in the vehicle trailer, and / or for other applications.

[0043] In some time-of-flight measurements, the light source 306 is an infrared laser source, and the optical sensor 310 is a time-of-flight 3D image sensor configured to measure infrared light (for example, illuminance) reflected from within a vehicle trailer 600, such as from a rear wall and away from objects inside the trailer. In some embodiments, the processor 302 controls the light source 306 and the diffuser 308 to produce an illumination output beam exhibiting a desired illuminance pattern. The processor 302 then controls the optical sensor 310 to collect infrared image data from inside the vehicle trailer, and this image data is analyzed, either in the optical sensor 310 or in the processor 302, to determine 3D image data from which the various characteristic values ​​for the vehicle trailer and the objects inside it can be determined.In this way, the lighting system 300 can determine the location of a rear wall 602 of the vehicle trailer 600, as well as the locations of side walls 604, a top wall 606, and a bottom wall 608. From this, the lighting system 300 can determine the total volume of the vehicle trailer 600. The lighting system 300 can also determine the location of the nearest object 609 within the vehicle trailer 600, from which the lighting system 300 can identify the location of an intermediate space 610. Using the techniques described here, the lighting system 300 can then determine an illumination volume 612 and the illumination pattern required to meet illumination criteria (and / or irradiance criteria) stored in the memory 304.

[0044] Although not shown, various embodiments allow for the use of multiple light sources to illuminate the desired volume of a vehicle trailer. For example, a light source can have two laser emitters, each with a different diffuser, where one laser emitter-diffuser pair creates a first form factor k1, and another laser emitter-diffuser pair creates a second form factor k2, where k1 ≠ k2, for example, k1 > k2 or k1 < k2. A processor in the lighting system then determines which laser emitter-diffuser pair is used to generate the desired illumination volume.Alternatively, in other embodiments, the processor may be programmed to control each pair to fill different sections of the illumination volume, so that the entire volume is filled by combining the output beams from both pairs. In some embodiments, one pair is used to satisfy a desired first illumination criterion, while the other pair is used to illuminate an interstitial plane to satisfy a desired second illumination criterion. In some embodiments, both pairs can be used to illuminate a back wall, and only one pair is used to illuminate an interstitial plane.

[0045] The techniques presented here provide examples of systems and methods for a lighting system that generates a pattern of illumination intensity capable of minimizing the number of light sources required for long-range applications, e.g., 10 m to 20 m, with 3D runtime, including the longitudinal dimension of 24 ft to 53 ft of the vehicle trailer, as is common in vehicle shipping applications. These techniques can be implemented in monitoring units incorporating runtime 3D sensors on trailers, although they are not limited to such applications and can be used in any number of applications where illumination criteria need to be maintained for a given volume of light.

[0046] Specific embodiments have been described in the preceding description. However, those skilled in the art know that various modifications and changes can be made without deviating from the scope of the invention as specified in the following claims. Therefore, the description and figures should be understood as illustrative and not as limiting, and all such modifications should be included within the scope of the present teachings.

[0047] The beneficial effects, advantages, problem solutions, and any elements that may produce or enhance a beneficial effect, advantage, or solution shall not be construed as critical, necessary, or essential features or elements of any claim or claims. The invention is defined solely by the attached claims, including any amendments made during the pendency of the present application and including all equivalents of those claims that are granted.

[0048] Furthermore, in this application, relational terms such as first and second, top and bottom, and the like, are used only to distinguish one quantity or action from another, without necessarily requiring or implying any actual relationship or order between such quantities or actions. Terms such as "exhibit," "have," "include," "contain," or other variations thereof are intended to cover non-inclusive inclusion, so that a process, procedure, object, or facility in which a list of elements exists may not only contain those elements but may also exhibit other elements that are not explicitly listed or inherent in such processes, procedures, objects, or facilities. An element to which "exhibits... has...", "contains...", "comprises..."The precedence of "a" does not, without further limitations, preclude the presence of additional identical elements in the process, procedure, object, or apparatus in which the element is provided. The terms "a" and the like are defined as one or more unless explicitly stated otherwise. The terms "substantial," "essential," "approximately," "about," or other versions thereof are to be understood as being close to what those skilled in the art would understand by them, and in a non-restrictive embodiment, such a term is defined as meaning within 10%, in another embodiment within 5%, in another embodiment within 1%, and in yet another embodiment within 0.5%.The term "coupled" as used here is defined as "connected," although not necessarily as directly connected, and not necessarily as mechanically connected. A device or structure that is "configured" in a certain way is at least configured in that way, but may also be configured in other ways not listed.

[0049] It should be noted that some embodiments may include one or more generic or specialized processors (or “processing devices”), such as microprocessors, digital signal processors, custom processors, and field-programmable gate arrays (FPGAs), and specific stored program instructions (including both software and hardware) that control the one or more processors to implement some, most, or all of the functions and / or facilities described herein in connection with certain circuits that are not processors.Alternatively, some or all of the functions can be implemented as a state machine that has no stored program instructions, or by one or more application-specific integrated circuits (ASICs) where each function, or some combinations of specific functions, is / are implemented as customer-specific logic. Naturally, a combination of both approaches can also be used.

[0050] Furthermore, an embodiment can be implemented as a computer-readable storage medium on which computer-readable code is stored for programming a computer (which, for example, has a processor) to perform a method as described and claimed herein. Examples of such computer-readable storage media include, but are not limited to, a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a ROM (read-only memory), a PROM (programmable read-only memory), an EPROM (erasable programmable read-only memory), an EEPROM (electrically erasable programmable read-only memory), and flash memory.Furthermore, it is expected that a person skilled in the art, despite potentially significant expenditure and numerous design choices, motivated, for example, by available time, current technology, and economic considerations, and guided by the concepts and principles disclosed herein, will easily be able to create such software instructions and programs as well as ICs with minimal experimental effort.

[0051] The summary of the disclosure is provided to enable the reader to easily assess the nature of the technical disclosure. It is submitted on the condition that it will not be used to interpret or limit the scope or meaning of the claims. Furthermore, it is evident from the preceding detailed description that various features of different embodiments are grouped together to avoid unnecessarily burdening the disclosure. This approach to the disclosure should not be interpreted as indicating an intention that the claimed embodiments require more features than those expressly stated in each claim.Instead, as can be seen from the following claims, the subject matter of the invention consists of fewer than all features of a single disclosed embodiment. Therefore, the following claims are included in the detailed description of the invention, each claim being a separate, independent subject matter.

Claims

[1] Lighting system (212) comprising: a light source (214) disposed at a proximal end of a volume and configured to emit a beam of photons; and a diffuser (216) arranged to receive the photon beam and to diffuse the photon beam into an output beam extending from a distal end plane of the volume to a space plane (220) in the volume to thereby define an illumination volume (218), the output beam having an illumination intensity that creates an irradiance threshold at a transverse and off-axis region of the distal end plane, the diffuser (216) further configured to maintain the irradiance at a transverse and off-axis region of the space plane (220) at or above the irradiance threshold at the transverse and off-axis region of the distal end plane, wherein the output beam has an illumination intensity that produces a first irradiance profile at the distal end plane and a second irradiance profile at the gap plane (220), wherein the diffuser (216) is configured such that the first irradiance profile varies across the distal end plane and the second irradiance profile varies across the gap plane (220), wherein the diffuser (216) is configured such that the illumination intensity of the output beam satisfies the following condition: I(Θ) ≤ I max (Θ) = I0cos(Θ), where Θ is an angle to an illumination axis of the output beam, and I0 is an illumination intensity on the illumination axis, wherein the diffuser (216) is configured such that the illumination intensity I of the output beam, expressed as I x (Θ)×I y (Θ), the following condition is met: lx(θx)≥lx_min(θx)=lx(θx0)cos(θx0)sin(θx0)2cos(θx)sin(θx)2 where Θ x0 is an angle to an illumination axis of the output beam, measured at the distal end plane along an x-axis, and Θ x is an angle relative to an illumination axis of the output beam along the x-axis; and: ly(θy)≥ly_min(θy)=ly(θy0)cos(θy0)sin(θy0)2cos(θy)sin(θy)2, where Θ y0 is an angle to an illumination axis of the output beam, measured at the distal end plane along a y-axis, and Θ y is an angle to an illumination axis of the output beam along the y-axis. [2] Lighting system (212) comprising: a light source (214) disposed at a proximal end of a volume and configured to emit a beam of photons; and a diffuser (216) arranged to receive the photon beam and to diffuse the photon beam into an output beam extending from a distal end plane of the volume to a space plane (220) in the volume to thereby define an illumination volume (218), the output beam having an illumination intensity that creates an irradiance threshold at a transverse and off-axis region of the distal end plane, the diffuser (216) further configured to maintain the irradiance at a transverse and off-axis region of the space plane (220) at or above the irradiance threshold at the transverse and off-axis region of the distal end plane, wherein the output beam has an illumination intensity that produces a first irradiance profile at the distal end plane and a second irradiance profile at the gap plane (220), wherein the diffuser (216) is configured such that the first irradiance profile varies across the distal end plane and the second irradiance profile varies across the gap plane (220), wherein the diffuser (216) is configured such that the illumination intensity of the output beam satisfies the following condition: I(Θ) ≤ I max (Θ) = I0cos(Θ), where Θ is an angle to an illumination axis of the output beam, and I0 is an illumination intensity on the illumination axis, wherein the diffuser (216) is further configured such that the illumination intensity I of the output beam, expressed as I x (Θ) × I y (Θ), the following condition is met: lx(θx)≥lx_min(θx)=lx(θx0)cos(θx0)sin(θx0)2cos(θx)sin(θx)2 where Θ x0 is an angle to an illumination axis of the output beam, measured at the distal end plane along an x-axis, and Θ x is an angle to an illumination axis of the output beam along the x-axis; and: ly(θy)≥ly_min(θy)=ly(θy0)cos(α)sin(α)2cos(α+θy)sin(α+θy)2 where Θ y0 is an angle to an illumination axis of the output beam, measured at the distal end plane along a y-axis, and Θ y is an angle to an illumination axis of the output beam along a y-axis, and wherein α is a deflection angle of the illumination axis relative to a reference direction for the illumination volume (218). [3] The lighting system (212) of claim 1, wherein the light source (214) comprises a plurality of infrared light sources, and wherein the diffuser (216) comprises a plurality of diffusers (216), each light source (214) having a corresponding diffuser (216) among the plurality of diffusers (216), and each diffuser (216) having a different diffuser pattern. [4] A method for illuminating a volume of interest, the method comprising: Generating a laser beam from a laser source located at a proximal end of the volume of interest; and Illuminating the volume of interest by scattering the laser beam into an output beam using a diffuser (216) that projects the output beam into the volume of interest so that it extends from a distal end plane of the volume to a space plane (220) in the volume, wherein the output beam has an illumination intensity that creates an irradiance threshold at a transverse and off-axis region of the distal end plane, and wherein the diffuser (216) scatters the output beam so that the irradiance at a transverse and off-axis region of the space plane (220) is maintained at or above the irradiance threshold at the transverse and off-axis region of the distal end plane, wherein scattering the output beam comprises maintaining a maximum illumination intensity in the volume of interest according to: I(Θ) ≤ I max (Θ) = I0cos(Θ), where Θ is an angle to an illumination axis of the output beam, and I0 is the illumination intensity on the illumination axis at the intersection of the illumination axis with the distal end plane, wherein scattering the output beam further comprises a minimum illumination intensity I of the output beam, as I x (Θ)×I y (Θ) expressed, to maintain, according to: lx(θx)≥lx_min(θx)=lx(θx0)cos(θx0)sin(θx0)2cos(θx)sin(θx)2 where Θ x0 is an angle to an illumination axis of the output beam, measured at the distal end plane along an x-axis, and where Θ x is an angle to an illumination axis of the output beam along the x-axis; and ly(θy)≥ly_min(θy)=ly(θy0)cos(θy0)sin(θy0)2cos(θy)sin(θy)2, where Θ y0is an angle to an illumination axis of the output beam, measured at the distal end plane along a y-axis, and Θ y is an angle to an illumination axis of the output beam along the y-axis. [5] A method for illuminating a volume of interest, the method comprising: Generating a laser beam from a laser source located at a proximal end of the volume of interest; and Illuminating the volume of interest by scattering the laser beam into an output beam using a diffuser (216) that projects the output beam into the volume of interest so that it extends from a distal end plane of the volume to a space plane (220) in the volume, wherein the output beam has an illumination intensity that creates an irradiance threshold at a transverse and off-axis region of the distal end plane, and wherein the diffuser (216) scatters the output beam so that the irradiance at a transverse and off-axis region of the space plane (220) is maintained at or above the irradiance threshold at the transverse and off-axis region of the distal end plane, wherein scattering the output beam comprises maintaining a maximum illumination intensity in the volume of interest according to: I(Θ) ≤ I max (Θ) = I0cos(Θ), where Θ is an angle to an illumination axis of the output beam, and I0 is the illumination intensity on the illumination axis at the intersection of the illumination axis with the distal end plane, wherein scattering the output beam further comprises maintaining a minimum illumination intensity of the output beam according to: lx(θx)≥lx_min(θx)=lx(θx0)cos(θx0)sin(θx0)2cos(θx)sin(θx)2 where Θ x0 is an angle to an illumination axis of the output beam, measured at the distal end plane along an x-axis, and where Θ x is an angle to an illumination axis of the output beam along the x-axis; and ly(θy)≥ly_min(θy)=ly(θy0)cos(α)sin(α)2cos(α+θy)sin(α+θy)2 where Θ y0 is an angle to an illumination axis of the output beam, measured at the distal end plane along a y-axis, where Θ yis an angle to an illumination axis of the output beam along a y-axis, and wherein α is a deflection angle of the illumination axis relative to a reference direction for the illumination volume (218). [6] A method for illuminating a volume of interest, the method comprising: Generating a laser beam from a laser source located at a proximal end of the volume of interest; and Illuminating the volume of interest by scattering the laser beam into an output beam using a diffuser (216) that projects the output beam into the volume of interest so that it extends from a distal end plane of the volume to a space plane (220) in the volume, wherein the output beam has an illumination intensity that creates an irradiance threshold at a transverse and off-axis region of the distal end plane, and wherein the diffuser (216) scatters the output beam so that the irradiance at a transverse and off-axis region of the space plane (220) is maintained at or above the irradiance threshold at the transverse and off-axis region of the distal end plane, wherein scattering the output beam comprises maintaining a maximum illumination intensity in the volume of interest according to: I(Θ) ≤ I max (Θ) = I0cos(Θ), where Θ is an angle to an illumination axis of the output beam, and I0 is the illumination intensity on the illumination axis at the intersection of the illumination axis with the distal end plane, and wherein scattering the output beam further comprises maintaining an illumination intensity of the output beam according to: lx(θx,kx):=min[cos(θx),(cos(θx0)sin(θx0)2cos(θx)sin(θx)2)kx] ly(θy,ky):=if θy<0,cos(θy),min[cos(θy),(cos(α)sin(α)2cos(θy+α)sin(θy+α)2)ky] where I x (Θ) is the illumination intensity along an x-axis as a function of Θ, which is an angle to the x-axis, where I y (Θ) is the illumination intensity along a y-axis as a function of Θ, where Θ x0 is an angle to an illumination axis of the output beam, measured at the distal end plane along an x-axis, where Θ xis an angle to an illumination axis of the output beam along the x-axis, where Θ y0 is an angle to an illumination axis of the output beam, measured at the distal end plane along a y-axis, where Θ y is an angle to an illumination axis of the output beam along a y-axis, and wherein α is a deflection angle of the illumination axis relative to a reference direction for the illumination volume (218). [7] The method of claim 4, wherein the laser source is an infrared laser source, and wherein the method further comprises acquiring images from within the volume of interest using a three-dimensional image sensor at the proximal end.

Images