PATENT DOCUMENT

Publication Number: US-12017577-B2
Application Number: US-202217721146-A
Country: US
Kind Code: B2

Title: Vehicles with automatic headlight alignment

Abstract:
A vehicle may have lights such as headlights. The lights may be moved using a positioner. Control circuitry in the vehicle may use sensor circuitry to monitor the environment surrounding the vehicle. The sensor circuitry may include one or more sensors such as a lidar sensor, radar sensor, image sensor, and/or other sensors to measure the shape of a surface in front of the vehicle and the location of the surface relative to the vehicle. These sensors and/or other sensors in the sensor circuitry also measure headlight illumination on the surface. Based on the known shape of the surface in front of the vehicle and the distance of the surface from the vehicle, the control circuitry can predict where a headlight should be aimed on the surface. By comparing predictions of headlight illumination on the surface to measurements of headlight illumination on the surface, the vehicle can determine how to move the headlight with the positioner to align the headlight.

Claims:
What is claimed is: 
     
       1. A vehicle, comprising:
 a vehicle body; 
 a headlight supported by the vehicle body that is configured to produce headlight illumination; 
 control circuitry configured to detect a difference between an expected direction of the headlight illumination and a measured direction of the headlight illumination; 
 an electrically adjustable positioner; and 
 a sensor configured to detect tilt of the vehicle body relative to a roadway, wherein the expected direction of the headlight illumination is based on the detected tilt and wherein the electrically adjustable positioner is configured to align the headlight in response to the detected difference between the expected direction of the headlight illumination and the measured direction of the headlight illumination when the control circuitry adjusts the electrically adjustable positioner in response to the detected tilt. 
 
     
     
       2. The vehicle defined in  claim 1  further comprising:
 forward-facing sensor circuitry on the vehicle body that is configured to capture a three-dimensional image of a surface in front of the vehicle body and that is configured to measure the headlight illumination from the headlight as the headlight illuminates the surface, wherein the control circuitry is configured to use the three-dimensional image and the measured headlight illumination on the surface in determining the expected direction of the headlight illumination. 
 
     
     
       3. The vehicle defined in  claim 2  wherein the forward-facing sensor circuitry comprises a two-dimensional image sensor configured to measure the headlight illumination. 
     
     
       4. The vehicle defined in  claim 2  wherein the forward-facing sensor circuitry comprises a lidar sensor that captures the three-dimensional image. 
     
     
       5. The vehicle defined in  claim 2  wherein the forward-facing sensor circuitry comprises a three-dimensional sensor configured to capture the three-dimensional image and wherein the three-dimensional sensor comprises a three-dimensional sensor selected from the group consisting of:
 a radar sensor, a stereoscopic camera, and a structured light sensor. 
 
     
     
       6. The vehicle defined in  claim 1  further comprising an additional sensor configured to measure the headlight illumination while the control circuitry adjusts the headlight to change the headlight illumination. 
     
     
       7. The vehicle defined in  claim 6  wherein the headlight comprises multiple light sources and wherein the additional sensor is configured to measure the headlight illumination while the control circuitry adjusts the multiple light sources to produce different respective amounts of light. 
     
     
       8. The vehicle defined in  claim 6  wherein the headlight is operable in a low-beam mode and a high-beam mode and wherein the additional sensor is configured to measure the headlight illumination while the control circuitry changes the headlight between operation in the low-beam mode and operation in the high-beam mode. 
     
     
       9. The vehicle defined in  claim 1  wherein the control circuitry is configured to adjust the electrically adjustable positioner based on information, wherein the information comprises information selected from the group consisting of: weather information, vehicle location information, and roadway information. 
     
     
       10. The vehicle defined in  claim 1  further comprising:
 navigation system circuitry configured to determine a vehicle location, wherein the control circuitry is configured to use the determined vehicle location to retrieve a three-dimensional surface shape from a database corresponding to a surface in front of the vehicle body; and 
 an image sensor configured to measure the headlight illumination from the headlight as the headlight illuminates the surface, wherein the control circuitry is configured to use the three-dimensional surface shape and the measured headlight illumination on the surface in determining the expected direction of the headlight illumination. 
 
     
     
       11. The vehicle defined in  claim 1  wherein the control circuitry is further configured to calibrate the electrically adjustable positioner while the vehicle body is parked. 
     
     
       12. A vehicle, comprising:
 a vehicle body; 
 a headlight that includes independently adjustable light sources and that is configured to produce headlight illumination on a surface in front of the vehicle body by activating different subsets of the independent adjustable light sources in sequence; 
 sensor circuitry configured to obtain a surface measurement on the surface and configured to obtain partially activated headlight illumination measurements of the headlight illumination on the surface, each of the partially activated headlight illumination measurements corresponding to the activation of a given subset of the different subsets of the independently adjustable light sources; 
 an electrically adjustable positioner configured to move the headlight relative to the vehicle body; and 
 control circuitry configured to adjust the electrically adjustable positioner to align the headlight, wherein the control circuitry is configured to adjust, when aligning the headlight, relative output intensities of the independently adjustable light sources based on the partially activated headlight illumination measurements. 
 
     
     
       13. The vehicle defined in  claim 12  wherein the sensor circuitry comprises a three-dimensional sensor and wherein the surface measurement comprises a three-dimensional surface shape gathered by the three-dimensional sensor. 
     
     
       14. The vehicle defined in  claim 13  wherein the three-dimensional sensor comprises a lidar sensor. 
     
     
       15. The vehicle defined in  claim 13  wherein the three-dimensional sensor comprises a stereoscopic sensor having a pair of cameras. 
     
     
       16. The vehicle defined in  claim 13  wherein the three-dimensional sensor comprises an optical sensor. 
     
     
       17. The vehicle defined in  claim 13  wherein the three-dimensional sensor comprises a radar sensor. 
     
     
       18. The vehicle defined in  claim 13  wherein the control circuitry is configured to determine expected output intensities of the different subsets of the independently adjustable light sources and is configured to compare the expected output intensities to the partially activated headlight illumination measurements. 
     
     
       19. The vehicle defined in  claim 18  wherein the control circuitry is configured to adjust the relative output intensities of the independently adjustable light sources based on the comparison of the expected output intensities to the partially activated headlight illumination measurements. 
     
     
       20. A vehicle, comprising:
 a vehicle body; 
 a headlight; 
 a positioner configured to move the headlight relative to the vehicle body; 
 a three-dimensional sensor configured to measure a surface of an object in front of the vehicle body; 
 an image sensor configured to measure a position on the surface where the headlight is pointed; and 
 control circuitry configured to:
 calibrate the positioner when the vehicle is parked by directing the positioner to move while making sensor measurements to evaluate accuracy of the movement; 
 use the measured surface to determine a predicated position on the object where the headlight is expected to be aimed when the headlight is aligned relative to the vehicle body; 
 compare the measured position to the predicated position; and 
 use the positioner to move the headlight based on the comparison. 
 
 
     
     
       21. The vehicle defined in  claim 20  wherein the surface has a shape, wherein the surface is located at a distance from the vehicle body, and wherein the three-dimensional sensor is configured to measure the shape of the surface in three dimensions and the distance of the surface from the vehicle body. 
     
     
       22. The vehicle defined in  claim 21  wherein the control circuitry is configured to use the calibrated positioner to move the headlight based on the comparison when the vehicle is traveling on a roadway.

Description:
This application claims the benefit of provisional patent application No. 63/298,365, filed Jan. 11, 2022, and provisional patent application No. 63/216,780, filed Jun. 30, 2021, which are hereby incorporated by reference herein in their entireties. 
    
    
     FIELD 
     This relates generally to systems such as vehicles, and, more particularly, vehicles that have lights. 
     BACKGROUND 
     Automobiles and other vehicles have lights such as headlights. To accommodate different driving conditions, headlights are sometimes provided with adjustable settings such as low beam and high beam settings. Some headlights can be steered during operation to accommodate road curvature. 
     SUMMARY 
     A vehicle may have lights such as headlights. Sensor circuitry in the vehicle may be used to measure the shape and location of surfaces in front of the vehicle. The sensor circuitry can also be used to measure how the headlights illuminate the surfaces as light from the headlights is projected onto the surfaces. For example, the sensor circuitry may measure where the headlights are aimed on the surfaces and can measure the pattern of light from the headlights on the surface as the headlight illumination is projected onto the surface. Light intensity measurements from an image sensor or other sensor may be used to obtain a peak headlight intensity position, may be used to locate edges in an illumination pattern, and may be used to determine other illumination characteristics. 
     Information on the three-dimensional shape of a surface in front of the vehicle can be used to predict where the headlights should be aimed and therefore the pattern of illumination from the headlights on the surface when the headlights are aligned relative to the vehicle. By comparing a prediction of headlight illumination intensity on the surface to measured headlight illumination intensity on the surface, the vehicle can determine how to move the headlight with the positioner to align the headlight. If desired, information on the three-dimensional shape of a surface in front of the vehicle may be obtained from a database. For example, a three-dimensional map of the environment may be stored in a navigation database. Information from satellite navigation system sensors and/or other navigation sensors may be used to determine vehicle location. The known vehicle location may then be used to retrieve corresponding three-dimensional surface shape information from the database. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a top view of an illustrative vehicle in accordance with an embodiment. 
         FIG.  2    is a side view of an illustrative adjustable headlight in accordance with an embodiment. 
         FIG.  3    is a perspective view of an illustrative scene with a target being illuminated by headlights in accordance with an embodiment. 
         FIG.  4    is a graph showing how headlight performance can be monitored by measuring headlight illumination intensity as a function of position across an illuminated surface in accordance with an embodiment. 
         FIG.  5    is a cross-sectional side view of an illustrative headlight with multiple independently adjustable elements in accordance with an embodiment. 
         FIG.  6    is a graph showing how measurements may be made on illumination from the headlight of  FIG.  5    in accordance with an embodiment. 
         FIG.  7    is a cross-sectional side view of an illustrative vehicle with headlights and sensor circuitry in accordance with an embodiment. 
         FIG.  8    is a flow chart of illustrative operations involved in using a vehicle with headlights in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     A system such as a vehicle or other system may have components that emit light such as headlights and other lights. Headlights may be used to illuminate roadways and other objects in the vicinity of a vehicle. The illumination provided by the headlights allows vehicle occupants to view the objects at night or in other dim ambient lighting conditions and facilitates the operation of sensors. For example, headlight illumination at visible and/or infrared wavelengths may be used to provide illumination for image sensors that are used by an autonomous driving system or driver&#39;s assistance system. 
     The illumination that is emitted by the headlights in a vehicle may be adjustable. For example, the headlights may have adjustable components that allow the headlights to be operated in high-beam and low-beam modes and to be steered to the left and right (e.g., to accommodate curves in a road). If desired, headlight adjustments may be made to calibrate the headlights. In this way, unintended misalignment of the headlights over time may be prevented. 
     To help ensure that headlights are properly aligned and therefore emit light beams in desired directions, a vehicle sensor such as a three-dimensional sensor may gather information on an object within range of the headlights. For example, a lidar sensor may be used to map the three-dimensional shape of a roadway and an object on the roadway in front of a vehicle. An image sensor in the vehicle can measure the pattern of illumination from the headlights that falls on the roadway and object. Measurements of headlight illumination reveal the direction in which a headlight is pointing. By comparing the expected illumination (e.g., the expected headlight illumination direction) with the measured illumination (e.g., the measured headlight illumination direction), variations in headlight performance can be detected and corrective action taken. If, as an example, it is determined that the headlights are pointed 5° too high, a positioner coupled to the headlights may be directed to automatically tilt the headlights downward by 5° to compensate for this measured misalignment. In this way, the headlights may be continually adjusted during use of the vehicle to ensure that the headlights operate satisfactorily. The headlights may also be adjusted based on measured and predicated changes in vehicle orientation relative to a roadway and other measured and predicated conditions. 
       FIG.  1    is a side view of a portion of an illustrative vehicle. In the example of  FIG.  1   , vehicle  10  is the type of vehicle that may carry passengers (e.g., an automobile, truck, or other automotive vehicle). Configurations in which vehicle  10  is a robot (e.g., an autonomous robot) or other vehicle that does not carry human passengers may also be used. Vehicles such as automobiles may sometimes be described herein as an example. As shown in  FIG.  1   , vehicle  10  may be operated on roads such as roadway  14 . Objects such as object  26  may be located on or near other structures in the vicinity of vehicle  10  such as roadway  14 . 
     Vehicle  10  may be manually driven (e.g., by a human driver), may be operated via remote control, and/or may be autonomously operated (e.g., by an autonomous driving system or other autonomous propulsion system). Using vehicle sensors such as lidar, radar, visible and/or infrared cameras (e.g., two-dimensional and/or three-dimensional cameras), proximity (distance) sensors, and/or other sensors, an autonomous driving system and/or driver-assistance system in vehicle  10  may perform automatic braking, steering, and/or other operations to help avoid pedestrians, inanimate objects, and/or other external structures such as illustrative obstacle  26  on roadway  14 . 
     Vehicle  10  may include a body such as vehicle body  12 . Body  12  may include vehicle structures such as body panels formed from metal and/or other materials, may include doors, a hood, a trunk, fenders, a chassis to which wheels are mounted, a roof, etc. Windows may be formed in doors  18  (e.g., on the sides of vehicle body  12 , on the roof of vehicle  10 , and/or in other portions of vehicle  10 ). Windows, doors  18 , and other portions of body  12  may separate the interior of vehicle  10  from the exterior environment that is surrounding vehicle  10 . Doors  18  may be opened and closed to allow people to enter and exit vehicle  10 . Seats and other structures may be formed in the interior of vehicle body  12 . 
     Vehicle  10  may have automotive lighting such as one or more headlights (sometimes referred to as headlamps), driving lights, fog lights, daytime running lights, turn signals, brake lights, and/or other lights. As shown in  FIG.  1   , for example, vehicle  10  may have lights such as lights  16 . In general, lights  16  may be mounted on front F of vehicle  10 , on rear R of vehicle  10 , on left and/or right sides W of vehicle  10 , and/or other portions of body  12 . In an illustrative configuration, which may sometimes be described herein as an example, lights  16  are headlights and are mounted to front F of body  12 . There may be, as an example, left and right headlights  16  located respectively on the left and right of vehicle  10  to provide illumination  20  in the forward direction (e.g., in the +X direction in which vehicle  10  moves when driven forward in the example of  FIG.  1   ). By shining headlights  16  on external surfaces  28  such as roadway  14  and object  26  in front of vehicle  10 , occupants of vehicle  10  may view surfaces  28  even in dim ambient lighting conditions (e.g., at night). The operation of sensors in vehicle  10  such as image sensors and other sensors that use light may also be supported by providing surfaces  28  with illumination. 
     Vehicle  10  may have components  24 . Components  24  may include propulsion and steering systems (e.g., manually adjustable driving systems and/or autonomous driving systems having wheels coupled to body  12 , steering controls, one or more motors for driving the wheels, etc.), and other vehicle systems. Components  24  may include control circuitry and input-output devices. Control circuitry in components  24  may be configured to run an autonomous driving application, a navigation application (e.g., an application for displaying maps on a display), and software for controlling vehicle climate control devices, lighting, media playback, window movement, door operations, sensor operations, and/or other vehicle operations. For example, the control system may form part of an autonomous driving system that drives vehicle  10  on roadways such as roadway  14  autonomously using data such as sensor data. The control circuitry may include processing circuitry and storage and may be configured to perform operations in vehicle  10  using hardware (e.g., dedicated hardware or circuitry), firmware and/or software. Software code for performing operations in vehicle  10  and other data is stored on non-transitory computer readable storage media (e.g., tangible computer readable storage media) in the control circuitry. The software code may sometimes be referred to as software, data, program instructions, computer instructions, instructions, or code. The non-transitory computer readable storage media may include non-volatile memory such as non-volatile random-access memory, one or more hard drives (e.g., magnetic drives or solid state drives), one or more removable flash drives or other removable media, or other storage. Software stored on the non-transitory computer readable storage media may be executed on the processing circuitry of components  24 . The processing circuitry may include application-specific integrated circuits with processing circuitry, one or more microprocessors, a central processing unit (CPU) or other processing circuitry. 
     The input-output devices of components  24  may include displays, sensors, buttons, light-emitting diodes and other light-emitting devices, haptic devices, speakers, and/or other devices for gathering environmental measurements, information on vehicle operations, and/or user input and for providing output. The sensors in components  24  may include ambient light sensors, touch sensors, force sensors, proximity sensors, optical sensors such as cameras operating at visible, infrared, and/or ultraviolet wavelengths (e.g., fisheye cameras, two-dimensional cameras, three-dimensional cameras, and/or other cameras), capacitive sensors, resistive sensors, ultrasonic sensors (e.g., ultrasonic distance sensors), microphones, radio-frequency sensors such as radar sensors, lidar (light detection and ranging) sensors, door open/close sensors, seat pressure sensors and other vehicle occupant sensors, window sensors, position sensors for monitoring location, orientation, and movement, speedometers, satellite positioning system sensors, and/or other sensors. Output devices in components  24  may be used to provide vehicle occupants and others with haptic output, audio output, visual output (e.g., displayed content, light, etc.), and/or other suitable output. 
     Three-dimensional sensors in components  24  may be formed from pairs of two-dimensional image sensors operating together as a stereoscopic depth sensor (e.g., a binocular camera pair forming at three-dimensional camera). Three-dimensional sensors may also be formed using image sensor systems that emit structured light (e.g., arrays of dots, lines, grids, and/or other structured light patterns at infrared and/or visible wavelengths) and that capture images (e.g., two-dimensional images) for analysis. The captured images reveal how the structured light patterns have been distorted by the three-dimensional surfaces illuminated by the structured light patterns. By analyzing the distortion of the structured light, the three-dimensional shape of the surfaces can be reconstructed. If desired, three-dimensional sensors for vehicle  10  may include one or more time-of-flight sensors. For example, time-of-flight measurements may be made using light (e.g., lidar sensor measurements) and radio-frequency signals (e.g., three-dimensional radar). 
     During operation, the control circuitry of components  24  may gather information from sensors and/or other input-output devices such as lidar data, camera data (e.g., two-dimensional images), radar data, and/or other sensor data. For example, three-dimensional image data may be captured using three-dimensional image sensor(s). Two-dimensional images (e.g., images of headlight illumination on one or more external surfaces such as external surface(s)  28  of  FIG.  1   ) may also be gathered. 
     A vehicle occupant or other user of vehicle  10  may provide user input to the control circuitry of vehicle  10 . Cameras, touch sensors, physical controls, and other input devices may be used to gather the user input. Using wireless communications with vehicle  10 , remote data sources may provide the control circuitry of components  24  with database information. Displays, speakers, and other output devices may be used to provide users with content such as interactive on-screen menu options and audio. A user may interact with this interactive content by supplying touch input to a touch sensor in a display and/or by providing user input with other input devices. If desired, the control circuitry of vehicle  10  may use sensor data, user input, information from remote databases, and/or other information in providing a driver with driver assistance information (e.g., information on nearby obstacles on a roadway and/or other environment surrounding vehicle  10 ) and/or in autonomously driving vehicle  10 . 
     Components  24  may include forward-facing sensor circuitry, as shown by forward-facing sensor(s)  24 F of  FIG.  1   . The forward-facing sensor circuitry may include one or more sensors facing a surface in front of vehicle  10  (e.g., one or more sensors that are directed in the +X direction of  FIG.  1    to detect surfaces  28  of structures in front of vehicle  10  such as obstacle  26  and roadway  14 ). Sensors  24 F and/or other sensors in vehicle  10  may include lidar, radar, visible and/or infrared cameras, and/or other sensors. For example, sensors  24 F may include two-dimensional image sensors and/or three-dimensional image sensors operating using structured light, binocular vision, time-of-flight (e.g., lidar or radar), and/or other three-dimensional imaging arrangements. Sensors  24 F may include a three-dimensional sensor that measures the three-dimensional shape of surface(s)  28  and that optionally measures the pattern of headlight illumination from headlights  16  on surface(s)  28 . If desired, a two-dimensional image sensor may be used to measure the headlight illumination pattern on surface(s)  28  (e.g., the forward-facing sensor circuitry of vehicle  10  may use three-dimensional and two-dimensional sensors to respectively measure surface shapes and headlight illumination intensity or both of these sensors may be used in gathering information on surface shape and/or surface illumination). 
     To ensure that surfaces  28  are sufficiently well illuminated to be visible to a user in vehicle  10  and to be visible to visible-light image sensors in sensors  24 F, headlights  16  may produce visible light illumination. To help ensure that optional infrared image sensors in forward-facing sensors  24 F receive sufficient reflected infrared light from the illuminated structures in front of vehicle  10 , headlights  16  may, if desired, produce infrared illumination. The forward-facing sensor circuitry of vehicle  10  that is used in measuring headlight illumination may be sensitive to visible light and, if desired, infrared light. 
     To correct for misalignment of headlights  16  over time (e.g., misalignment due to shifts in the mounting structures for headlights  16 , changes in vehicle suspension components, etc.), the control circuitry of vehicle  10  may control positioners in headlights  16  dynamically based on sensor measurements (e.g., based on discrepancies between an expected pattern of headlight illumination and a measured pattern of illumination). If, as an example, headlights  16  are pointed too high, a positioner may be used to tilt headlights  16  downwards so that headlights  16  are aimed appropriately. In this way, headlights  16  may be automatically compensated for misalignment and may remain aligned during operation of vehicle  10 . 
       FIG.  2    is a cross-sectional side view of an illustrative headlight showing how the headlight may be mounted to body  12 . Body  12  may have a cavity that receives headlight  16 , headlight  16  may be attached to an outer surface of body  12 , and/or headlight  16  may be otherwise supported by body  12 . As shown in  FIG.  2   , headlight  16  may include headlight housing  30  and one or more lenses or other optical components such as headlight lens  32 . Housing  30  may include support structures and enclosure structures for supporting the components of headlight  16 . These structures may facilitate mounting of headlight  16  to body  12 . Housing  30  may include polymer, metal, carbon-fiber composites and other fiber composites, glass, ceramic, other materials, and/or combinations of these materials. Lens  32  may include polymer, glass, transparent ceramic, and/or other materials that are transparent to visible light and infrared light (e.g., near infrared light). Headlight  16  includes a light source such as light source  40  that emits light  20 . Light  20  may include visible light (e.g., light from 400 nm to 750 nm) and, if desired, may include infrared light (e.g., near infrared light at one or more wavelengths from 800 to 2500 nm or other suitable infrared light). Lens  32  may be formed from one or more lens elements and may be used to help collimate light  20  and direct light  20  from headlight  16  in desired directions (e.g., to produce a beam of illumination in the +X direction). 
     Light source  40  may include one or more light-emitting devices such as light-emitting diodes, lasers, lamps, or other components that emit light. Optical elements such as reflectors, lenses, diffusers, colored elements, filters, adjustable shutters for adjusting the output of headlight  16  between low-beam and high-beam illumination patterns, and/or other optical components may be included in headlamp  16  (e.g., such optical elements may be included in housing  30 ). Independently adjustable light-emitting diodes and electrically adjustable components such as adjustable shutters and/or other adjustable optical components associated with headlight  16  may be adjusted by the control circuitry of vehicle  10  to adjust the direction of light  20  and the shape of the area covered by light  20  (e.g., to adjust light  20  to produce a desired low-beam or high-beam illumination pattern and/or other illumination pattern(s), to steer light  20 , etc.). 
     A positioner such as positioner  44  may be used to adjust the position and therefore the angular orientation of headlight  16  relative to body  12 . Positioner  44  may include one or more electrically adjustable actuators such as actuators  42  and may include optional manually adjusted positioning components (e.g., threaded members that can be rotated with a manual or motorized screwdriver to adjust the position of headlight  16 ). Actuators  42  may include one or more motors, solenoids, and/or other actuators. In response to commands from the control circuitry of vehicle  10 , the positioner formed from actuator(s)  42  may be used to translate headlight  16  along the X, Y, and/or Z axes and/or other axes and/or may be used to rotate headlight  16  about the X, Y, and/or Z axes and/or other axes. As one example, actuators  42  may tilt headlight  16  up and down relative to the structures in front of vehicle  10  by rotating headlight  16  about the Y axis of  FIG.  2    and may rotate headlight  16  to the left and right about the Z axis of  FIG.  2   . If desired, the positioner for headlight  16  may be used to make different types of position adjustments (e.g., rotations about the X axis, translation and/or rotation relative to another axis, etc.). The use of a positioner such as positioner  44  of  FIG.  2    that is formed from one or more actuators  42  in vehicle  10  to tilt headlight  16  up/down and to rotate headlight  16  right/left is illustrative. 
     During operation, vehicle  10  may adjust headlights  16  to accommodate different driving conditions. One or more adjustable shutters, adjustable light-emitting devices, and/or other adjustable components in headlights  16  may be controlled by the control circuitry of vehicle  10 . If desired, high-beams or low-beams may be selected based on user input and/or based on oncoming traffic detected using one or more sensors. As another example, when it is determined (from a steering system sensor, location sensor, lidar sensor, etc.) that the roadway on which vehicle  10  is traveling is starting to curve to the left, headlights  16  can automatically be turned to the left by the positioner to ensure that the roadway is satisfactorily illuminated by light  20 . Headlights  16  may also be turned on and off and/or otherwise adjusted based on measured ambient lighting conditions, weather, and other factors. 
     Adjustments to the position of headlights  16  may also be made for calibration purposes. For example, to avoid risk that headlights  16  might become misaligned over time, vehicle  10  may monitor the alignment of headlights  16 . Vehicle  10  may, as an example, use forward-facing sensor circuitry to map the structures in front of vehicle  10  and to measure the pattern of illumination on these structures. From these measurements, the control circuitry of vehicle  10  may determine which (if any) corrective actions are to be taken. For example, vehicle  10  may determine how headlights  16  should be repositioned by positioner  44  to correct for detected changes in headlight alignment. 
     To map the structures in front of vehicle  10 , vehicle  10  may use a three-dimensional sensor to gather a three-dimensional image of the structures. The three-dimensional sensor may be a lidar sensor, a radar sensor, a stereoscopic camera, a structured light sensor, or other three-dimensional image sensor that can gather three-dimensional images. Consider, as an example, the scenario of  FIG.  3   . In the example of  FIG.  3   , vehicle  10  is traveling on roadway  14  (e.g., a public road, a driveway, etc.). A three-dimensional sensor in forward-facing sensor(s)  24 F is facing forward in the +X direction. Surfaces  28  are associated with the portion of roadway  14  in front of vehicle  10  and object  26  and are in the field of view of the three-dimensional sensor. The three-dimensional sensor may therefore capture a three-dimensional image of surfaces  28  to determine the shape (e.g., the location in three dimensions) of roadway  14  and the shape (e.g., the location in three-dimensions) of object  26 . The captured shape information includes information on the distance between vehicle  10  and surfaces  28 . Objects such as roadway  14  and object  26  may receive illumination from headlights  16  and may therefore sometimes be referred to as target objects or a target. 
     Object  26  of surfaces  28  may be a test target that has a predetermined set of registration marks  50  (sometimes referred to as fiducials, optical targets, or alignment marks) or may be any other object (e.g., an everyday object such as a wall, garage door, vehicle, or other structure). As an example, object  26  may be an external object that contains detectable surface markings  54  (e.g., visually apparent markings or other characteristics that allow the three-dimensional sensor to sense the shape and appearance surfaces  28 ). The presence of marks  50  and/or other markings  54  may assist vehicle  10  in accurately measuring the location surfaces  28 . For example, alignment marks  50  may be separated by known distances from each other, so analysis of an image that contains marks  50  may help determine the distance of object  26  to vehicle  10  and may help determine the angular orientation of object  26  relative to vehicle  10 . In three-dimensional sensors based on stereoscopic image sensors, the presence of marks  50  and/or markings  54  may help in the construction of three-dimensional images from stereoscopic pairs of two-dimensional images. If desired, sensor data from multiple sources in the forward-facing sensor circuitry of vehicle  10  may be combined to further enhance three-dimensional surface shape measurements. As an example, three-dimensional image data from a lidar sensor may be combined with three-dimensional data from a stereoscopic camera, three-dimensional radar data, and data from a two-dimensional sensor. 
     Based on the three-dimensional image of surfaces  28  that is captured using the three-dimensional image sensor, vehicle  10  can determine the expected projection of headlight beams (illumination  20 ) from headlights  16  onto surfaces  28 . A two-dimensional image sensor or other sensor(s) in sensor(s)  24 F may measure the actual pattern of illumination  20  projected onto surfaces  28 , so that the actual and expected projection patterns can be compared to identify discrepancies. 
     Consider, as an example, a scenario in which object  26  is a planar surface that is 10 meters in front of vehicle  10  and that is orientated perpendicular to vehicle  10 . Using the three-dimensional image of surfaces  28 , vehicle  10  can determine the location and orientation of object  26  (e.g., 10 m in front of vehicle  10 ) and can determine the tilt and/or other characteristics of roadway  14 . The three-dimensional image of roadway  14  may reveal, as an example, that roadway  14  is flat and horizontal. Based on the known shape of surfaces  28  (e.g., the known position of the surface of object  26  relative to vehicle  10  and roadway  14 ), vehicle  10  (e.g., the control circuitry of components  24 ) may determine the position of headlights  16  relative to surfaces  28  and thereby predict the locations on surfaces  28  of left and right headlight illumination center points  52  on object  26  that are to be produced by left and right headlights  16  in vehicle  10 , respectively. If desired, headlight operation may be characterized by making other headlight illumination intensity measurements (e.g., measurements that identify the edges of a headlight beam, or other headlight illumination measurements that determine the direction of the headlight illumination). 
     Due to vibrations and normal aging in the mounting components for headlights  16  and/or other variations in vehicle  10  over time, there may be a tendency for headlights  16  to move out of perfect alignment. As an example, in the absence of intervention, the left and right headlights of vehicle  10  might slowly begin to aim higher than nominal. Knowing the distance of object  26  from headlights  16  and the nominal (correct) orientation of headlights  16 , vehicle  10  can predict the correct location of headlight aiming points  52 . By capturing an image of the projected output of headlights  16 , the actual orientation of headlights  16  (e.g., the actual direction in which headlights  16  are pointed) can be measured and compared with the expected orientation of headlights  16  when perfectly aligned (e.g., the expected direction in which headlights  16  should be pointed). For example, an image sensor in vehicle  10  may capture an image of surfaces  28  while surfaces  28  are under illumination from headlights  16 . The pattern of light  20  projected onto surfaces  28  (e.g., object  26  and roadway  14 ) may reveal that headlights  16  are pointed 10 cm higher on the surface of object  26  than expected (e.g., points  52  may be 10 cm too high, in this example). Because the shape of surfaces  28  is known and the distance from headlights  16  to the surface of object  26  is known, vehicle  10  can determine from the measured 10 cm vertical offset of points  52  that headlights  16  are pointed 2° too high (as an example). Based on this determination, positioner  44  can be directed to tilt headlights  16  downwards by 2° to compensate for the measured 2° of angular misalignment. This aligns headlights  16  so that they point were expected and so that points  52  on object  26  coincide with their expected positions. In this way, the overall pattern of illumination produced when light  20  strikes surfaces  28  will be as desired. 
     In monitoring headlight performance, vehicle  10  may measure the peak intensity of headlight illumination  20 , may measure the edges of illumination  20  (e.g., the boundary of the illumination pattern), and/or may measure other headlight performance parameters to characterize the output of headlights  16 . One or more of these measured headlight performance parameters may then be compared to corresponding predicted headlight performance parameters. 
     Consider, as an example, the headlight output shown in the graph of  FIG.  4   . In the example of  FIG.  4   , headlight output intensity I has been plotted as a function of DISTANCE (e.g., distance across surfaces  28  parallel to the X axis or Y axis of  FIG.  3   ). Solid line  60  corresponds to the expected output of headlight  16  when headlight  16  is properly aligned (e.g., a prediction based on the measured shape of surfaces  28  and the known nominal operating characteristics of headlights  16  when aligned). Dashed line  62  corresponds to the measured output of headlight  16  (e.g., the output measured by capturing an image of surfaces  28  while illuminated by light  20 ). To determine how much measured performance varies from expected performance, vehicle  10  may determine the location of the peak in intensity I for each curve, may determine the locations of the edges of each curve, and/or may otherwise measure the intensity and position of the light output from headlights  16 . 
     As shown in  FIG.  4   , for example, expected intensity curve  60  has an expected intensity peak  64 , whereas measured curve  62  has a measured intensity peak  66  that is shifted by a distance DP with respect to peak  64 . Vehicle  10  may compare points  64  and  66  to determine the value of DP and/or vehicle  10  may gather information on the expected and measured intensity patterns for headlights by comparing edge intensities (see, e.g., points  68 , which correspond to the positions of the edges of the headlight illumination pattern where expected intensity  60  has fallen to intensity threshold ITH and points  70  which correspond to the measured positions of these edges where measured intensity  62  has intensity threshold ITH). Using illumination pattern edges, peaks, and/or other illumination pattern characteristics, predicated and measured headlight information (e.g., curves  60  and  62 ) can be compared by vehicle  10  to determine the amount by which positioner  44  should be adjusted to align headlights  16 . Headlights  16  may be aligned collectively (e.g., measurements may take place while left and right headlights are illuminated) or may be aligned individually (e.g., by making a first measurement while the left headlight is illuminated but not the right headlight and by making a second measurement while the right headlight is illuminated but not the left). 
     If desired, headlights  16  may contain multiple individually adjustable headlight elements. As shown in  FIG.  5   , for example, headlight  16  may have multiple headlight elements  72 , each of which is individually adjustable. Elements  72  may have independently adjustable light sources (e.g., each element  72  may correspond to a separate light-emitting diode) and/or elements  72  may have independently adjustable shutters or other light-adjusting devices. To enhance the accuracy of headlight output characterization measurements, one or more of elements  72  may be used to produce illumination while remaining elements  72  do not produce illumination. By cycling through each element  72  (or set of elements), different corresponding output intensity measurements corresponding to each element  72  (or set of elements) may be obtained. Consider, as an example, a scenario in which there are three separate light-emitting diodes in headlight  16  (e.g., elements  72  correspond to individually adjustable light sources). To determine whether headlight  16  needs to be aligned, each of the three light-emitting diodes may be turned on in sequence while corresponding images of surfaces  28  under the resulting illumination are captured. In this way, more detailed headlight illumination measurements may be made than if all elements  72  were turned on at the same time. 
       FIG.  6    shows how this type of approach may produce multiple partially activated headlight output curves, each of which corresponding to activation of a separate respective element  72 . For each element  72 , vehicle  10  may produce a corresponding expected output curve  74  and may measure a corresponding actual output intensity (curve  76 ). By gathering headlight performance data using more granular measurements such as these, headlight performance can be gauged more accurately then when all elements  72  are activated together. Following characterization of each separate element  72  (e.g., by measuring how much expected curves  74  are shifted relative to measured curves  76 ) any headlight misalignment may be accurately determined. Positioner  44  may then be used to move headlight  16  (e.g., to adjust the angular orientation of headlight  16 ) and/or the relative intensities of each element  72  may be adjusted to align headlights  16  and to help ensure that headlights  16  provide illumination in a desired pattern. 
     Vehicle  10  may make measurements on surfaces  28  and the projected headlight illumination on surfaces  28  when parked next to a calibration target (e.g., a screen or other object with registration marks  50 ), when parked next to a wall, garage door, or other structure, or during normal operation traveling on a road (e.g., when vehicle  10  is being driven autonomously or manually through traffic). 
     Depending on the operating conditions for vehicle  10 , vehicle  10  may tilt or otherwise changes its orientation relative to roadway  14 . As shown in  FIG.  7   , for example, vehicle  10  may tilt forward when decelerating. This tilt may be detected by a three-dimensional sensor in forward-facing sensors  24 F and, if desired, may be detected using sensors such as sensors  24 T (e.g., suspension displacement sensors that sense how much wheels  78  are protruding from vehicle body  12  to determine the orientation of vehicle body  12  relative to roadway  14 ). By measuring the orientation of vehicle  10  relative to roadway  14 , the expected location of the headlight illumination on surfaces  28  may be determined. If, for example, it is determined that vehicle  10  is tilting downwards, the expected location of points  52  of  FIG.  3    will be lower than if it is determined that vehicle  10  is tilting upwards. Accordingly, sensor information such as vehicle suspension sensor information and/or other tilt sensor information may be taken into account when predicting the location of headlight output on a target. 
     If desired, positioner  44  may be controlled, one or more light sources and/or light modulating components may be controlled (see, e.g., elements  72  of  FIG.  5   ), and/or other adjustable components associated with headlights  16  may be controlled to adjust illumination  20  (e.g., while vehicle  10  is being driven). These adjustments may be made based on sensor measurements that reveal vehicle tilt, road characteristics such as the presence or predicted presence of speed bumps in roadway  14  (see, e.g., bump  14 B), weather (e.g., whether rain or other precipitation is present or is not present), ambient lighting conditions, predicated or detected turns in roadway  14 , geographic vehicle location, and/or other conditions of vehicle  10  when parked, when being driven, etc. If desired, vehicle  10  may have sensors such a sensors  241 . Sensors  241  may be, for example, inertial measurement units containing compasses, accelerometers, and/or gyroscopes and may be used to measure the orientation of vehicle body  12 , forward-facing sensors  24 F, and/or headlights  16  with respect to gravity. 
     Consider, as an example, a scenario in which the control circuitry of vehicle  10  uses a sensor or other data source to determine that vehicle  10  is starting to turn to the left along roadway  14 . Vehicle  10  may obtain information on the left turn in roadway  14  from a map database or other external databased, from lidar measurements or other forward-facing sensor measurements, from inertial measurement unit measurements, from steering system components (e.g., steering position sensors), and/or from other sources. In response to detecting that a left-hand bend is present or is upcoming, vehicle  10  may use positioner  44  to turn headlights  16  to the left. This helps ensure that illumination  20  will be present on roadway  14 . As another example, if an upcoming bump such as bump  14 B is detected, vehicle  10  can automatically adjust the position of headlight  16  as vehicle  10  travels over bump  14 B to help maintain a desired direction for headlight illumination  20  (e.g., to help ensure that headlight illumination  20  is directed straight forward, even as vehicle  10  tilts due to movement of wheels  78  over bump  14 B. If desired, headlights  16  may support low-beam and high-beam modes. Vehicle  10  may switch between these modes based on sensor data from sensors in vehicle  10  such as rain sensors (e.g., moisture sensors), ambient light sensors, oncoming headlight sensors, traffic sensors, and/or other sensors. Headlight movements such as movements to accommodate bends in a road may be taken into account during automatic alignment operations. For example, if headlights  16  have been turned to the left due to the presence of a left turn in roadway  14 , vehicle  10  will expect that headlight illumination  20  will likewise be moved to the left on surfaces  28  and can therefore take this information into account when measuring headlight output to assess headlight alignment. 
     Illustrative operations involved in using vehicle  10  are shown in  FIG.  8   . 
     During the operations of block  80 , headlights  16  may be used to illuminate object  26 , roadway  14  (e.g., surfaces  28  of  FIG.  3   ). Left and right headlights  16  may be illuminated simultaneously or separately. In headlight configurations in which each headlight has multiple adjustable elements such as elements  72  of  FIG.  5   , these elements may, if desired, be individually adjusted during the operations of block  80  (e.g., to provide information during headlight characterization on the individual contributions of these elements to different portions of the headlight illumination supplied by headlights  16 ). 
     During the operations of block  82 , a three-dimensional sensor in forward-facing sensors  24 F may be used to capture images of surfaces  28  (e.g., three-dimensional images may be captured). The presence of registration marks  50  on a target surface such as the surface of object  26  and/or other detectable features such as markings  54  may facilitate the capturing of satisfactory three-dimensional image data from a target. In addition to obtaining a three-dimensional map (shape) for surfaces  28 , vehicle  10  may capture an image of the headlight illumination from headlight(s)  16  that is present on surfaces  28 . For example, a visible light image and/or an infrared image from a three-dimensional image sensor, a separate two-dimensional image sensor, or other sensor may be captured that shows the location of the peak intensity of headlight illumination and/or that shows other headlight illumination features (e.g., the locations of the edges of the headlight illumination pattern). 
     If desired, information on the three-dimensional shapes of surfaces in front of the vehicle may be obtained from a local (in-vehicle) and/or remote navigation system database in addition to or instead of obtaining three-dimensional shape information. For example, a three-dimensional map of the environment may be stored in a navigation database for use in driving assistance functions and/or autonomous driving functions. Information from navigation system sensors (e.g., Global Positioning System circuitry and/or other satellite navigation system circuitry, inertial measurement units, lidar, image recognition systems, and/or other navigation sensors) may be used to determine vehicle location (position and orientation). The vehicle location information that is obtained from the navigation system sensors in this way may be used to retrieve corresponding three-dimensional surface shape information from the database (e.g., the three-dimensional shapes of surfaces at the determined vehicle location. 
     After measuring the shape of surfaces  28  and/or otherwise determining the shape of surfaces  28  (e.g., by obtaining information from a database) and measuring the pattern of headlight illumination  20  that is illuminating surfaces  28 , vehicle  10  may, during the operations of block  84 , determine the expected pattern of the headlight illumination on surfaces  28  (e.g., the expected peak intensity position of headlight output, the expected location of headlight beam edges, and other characteristics associated with the direction in which the headlight illumination is expected to be pointing). The expected headlight illumination pattern is determined based on the known shape of surfaces  28  (e.g., the location in three dimensions of surfaces  28  relative to vehicle  10 ), and the known nominal performance characteristics of headlights  16  (e.g., the known size and shape of the beam of light emitted by each headlight. During block  84 , vehicle  10  measures the actual headlight illumination pattern produced on surfaces  28  by headlights  16  and compares the measured headlight illumination information to the expected headlight illumination information. 
     If the expected and measured illumination patterns (center position, edge position, etc.) do not match, corrective action may be taken based on the results of the comparison to align headlights  16 . For example, during the operations of block  86 , the control circuitry of vehicle  10  may direct positioner  44  to tilt headlight  16  downwards by 3° in response to detection of an undesired 3° upward tilt. As shown by line  88 , the automatic alignment operations of  FIG.  8    may be performed repeatedly (e.g., whenever vehicle  10  is parked, periodically according to a schedule, whenever satisfactory surfaces  28  are available in front of vehicle  10 , in response to a user input command, and/or in response to determining that other headlight calibration criteria have been satisfied). 
     Although sometimes described in the context of headlights, any suitable lights in vehicle  10  may be aligned using the approach of  FIG.  8    (e.g., fog lights, tail lights, parking lights, supplemental side lighting, etc.). In addition to performing headlight alignment operations, the control circuitry of vehicle  10  may, if desired, use sensor measurements to calibrate actuators such as positioner  44 . As an example, when vehicle  10  is parked, positioner  44  may be calibrated by directing positioner  44  to move while making corresponding sensor measurements to evaluate the accuracy of these movements. Examples of sensors that may be used in gauging actuator performance so that compensating calibration operations may be performed include light sensors (e.g., an image sensor that measures whether light output from headlight  16  moves by 4.5° when positioner  44  is directed to move by 4.5°) and inertial measurement units (e.g., an inertial measurement unit coupled to positioner  44  that measures the angular movement of positioner  44  during calibration). Calibrating positioner  44  while vehicle  10  is stationary (parked), enables vehicle  10  to more accurately perform open loop control of the aim of positioner  44  when driving based on navigation system information (inertial measurement unit data and satellite navigation system data) and other data. 
     The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20220414
Publication Date: 20240625
Grant Date: 20240625
Priority Date: 20210630
Inventors: CHILD, CHRISTOPHER P
MAZUIR, Clarisse
STIEHL, KURT R
ZURCHER, MARK A
MANNBERG, MIKAEL B
GARRONE, RYAN J
TANG, XIAOFENG
Assignee: APPLE INC
CPC Classifications: [{"code": "B60Q1/0023", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q2300/324", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60Q1/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q2300/13", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01B11/24", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01B11/272", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01M11/068", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01M11/065", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01M11/064", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01S17/89", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q2300/322", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60Q1/115", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q2300/324", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60Q2300/322", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60Q2300/13", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60Q1/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01S17/89", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01M11/068", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01M11/065", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01B11/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01M11/068", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01M11/064", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01M11/065", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01B11/272", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01B11/24", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60Q1/11", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01B11/272", "inventive": true, "first": true, "tree": "[]"}, {"code": "B60Q1/115", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01B11/24", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60Q2300/324", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60Q2300/322", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60Q2300/13", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01S17/89", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01M11/068", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01M11/065", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01M11/064", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01B11/272", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q1/115", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q1/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q1/0023", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q1/11", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 82594867