Patent Publication Number: US-2023135748-A1

Title: Sensor assembly with cleaning

Description:
BACKGROUND 
     Vehicles typically include sensors. The sensors can provide data about operation of the vehicle, for example, wheel speed, wheel orientation, and engine and transmission data (e.g., temperature, fuel consumption, etc.). The sensors can detect the location and/or orientation of the vehicle. The sensors can be global positioning system (GPS) sensors; accelerometers such as piezo-electric or microelectromechanical systems (MEMS); gyroscopes such as rate, ring laser, or fiber-optic gyroscopes; inertial measurements units (IMU); and/or magnetometers. The sensors can detect the external world, e.g., objects and/or characteristics of surroundings of the vehicle, such as other vehicles, road lane markings, traffic lights and/or signs, pedestrians, etc. For example, the sensors can be radar sensors, scanning laser range finders, light detection and ranging (LIDAR) devices, and/or image processing sensors such as cameras. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of an example vehicle with an example sensor assembly. 
         FIG.  2    is a rear perspective view of the sensor assembly. 
         FIG.  3    is a perspective view of a portion of the sensor assembly. 
         FIG.  4    is a top cross-sectional view of a portion of the sensor assembly. 
         FIG.  5    is a diagram of an example cleaning system of the sensor assembly. 
         FIG.  6    is a plan view of an example sensor and nozzles of the sensor assembly. 
         FIG.  7    is a perspective side view of a portion of the sensor assembly. 
         FIG.  8    is a top view of a floor of a housing of the sensor assembly. 
     
    
    
     DETAILED DESCRIPTION 
     A sensor assembly includes a sensor including a sensor lens, the sensor lens defining an axis; a housing panel including an aperture centered on the axis, the sensor lens being recessed from the aperture along the axis; and an air nozzle positioned between the aperture and the sensor lens along the axis and oriented to blow horizontally across the sensor lens. The aperture and the sensor lens define a gap positioned on an opposite lateral side of the sensor lens from the air nozzle. 
     The aperture may have a circular shape that is orthogonal to the axis. 
     The aperture and the sensor lens may further define the gap positioned in an upward direction from the sensor lens. 
     The aperture and the sensor lens may further define the gap positioned in a downward direction from the sensor lens. 
     The aperture and the sensor lens may further define the gap extending circumferentially around the axis from the air nozzle to the air nozzle. The gap may have a constant axial width between the sensor lens and the aperture circumferentially around the axis from the air nozzle to the air nozzle. 
     The axis may be oriented horizontally. 
     The sensor assembly may further include a housing including the housing panel, the housing may include a chamber, and the gap may be positioned to direct airflow from the air nozzle into the chamber. The housing may include a drainage channel positioned inside the chamber and shaped to direct fluid to outside the housing. 
     The sensor may be positioned in the chamber. 
     The sensor may be a first sensor, the sensor lens may be a first sensor lens, the aperture may be a first aperture, the housing panel may be a first housing panel, the air nozzle may be a first air nozzle, the gap may be a first gap, the sensor assembly may further include a second sensor including a second sensor lens defining a second axis and a second air nozzle, the housing may include a second housing panel including a second aperture centered on the second axis, the second sensor lens may be recessed from the second aperture along the second axis, the second air nozzle may be positioned between the second aperture and the second sensor lens along the second axis and oriented to blow horizontally across the second sensor lens, the second aperture and the second sensor lens may define a second gap positioned on an opposite lateral side of the second sensor lens from the second air nozzle, and the second gap may be positioned to direct airflow from the second air nozzle into the chamber. The first sensor and the second sensor may be positioned in the chamber. 
     The housing panel may include a recessed portion, and the aperture may be positioned at a most recessed point of the recessed portion. The recessed portion may extend from the aperture radially outwardly and axially away from the sensor lens relative to the axis. 
     The sensor assembly may further include a blower positioned to supply airflow to the air nozzle. The sensor assembly may further include a duct positioned to direct airflow from the blower to the air nozzle. 
     The sensor assembly may further include a liquid nozzle positioned between the aperture and the sensor lens along the axis and oriented to spray across the sensor lens. The liquid nozzle may be positioned circumferentially relative to the axis less than 90° from the air nozzle. 
     The liquid nozzle may be positioned in the gap. 
     The air nozzle may include an outlet having a slot shape elongated parallel to the sensor lens. 
     With reference to the Figures, wherein like numerals indicate like parts throughout the several views, a sensor assembly  102  of a vehicle  100  includes a sensor  104  including a sensor lens  106 , the sensor lens  106  defining an axis A; a housing panel  108  including an aperture  110  centered on the axis A, the sensor lens  106  being recessed from the aperture  110  along the axis A; and an air nozzle  112  positioned between the aperture  110  and the sensor lens  106  along the axis A and oriented to blow horizontally across the sensor lens  106 . The aperture  110  and the sensor lens  106  define a gap  114  positioned on an opposite lateral side of the sensor lens  106  from the air nozzle  112 . 
     The gap  114  can provide a path for the airflow that travels across the sensor lens  106  from the air nozzle  112 . The sensor assembly  102  can thus avoid a “dead zone” of low-speed or still air on a portion of the sensor lens  106  farthest from the air nozzle  112 . Such a dead zone can prevent fluid or debris from being removed from that portion of the sensor lens  106 . Moreover, by permitting the airflow to travel inside the housing panel  108 , the sensor assembly  102  can help prevent fluid or debris from being carried by the airflow to other sensor lenses  106  of the sensor assembly  102 . 
     With reference to  FIG.  1   , the vehicle  100  may be any passenger or commercial automobile such as a car, a truck, a sport utility vehicle, a crossover, a van, a minivan, a taxi, a bus, etc. 
     The vehicle  100  may be an autonomous vehicle. The computer can be programmed to operate the vehicle  100  independently of the intervention of a human operator, completely or to a lesser degree. The computer may be programmed to operate the propulsion, brake system, steering system, and/or other vehicle systems based at least in part on data received from the sensors  104 . For the purposes of this disclosure, autonomous operation means the computer controls the propulsion, brake system, and steering system without input from a human operator; semi-autonomous operation means the computer controls one or two of the propulsion, brake system, and steering system and a human operator controls the remainder; and nonautonomous operation means a human operator controls the propulsion, brake system, and steering system. 
     The vehicle  100  includes a body  116 . The vehicle  100  may be of a unibody construction, in which a frame and the body  116  of the vehicle  100  are a single component. The vehicle  100  may, alternatively, be of a body-on-frame construction, in which the frame supports the body  116  that is a separate component from the frame. The frame and the body  116  may be formed of any suitable material, for example, steel, aluminum, etc. The body  116  includes body panels  118  partially defining an exterior of the vehicle  100 . The body panels  118  may present a class-A surface, e.g., a finished surface exposed to view by a customer and free of unaesthetic blemishes and defects. The body panels  118  include, e.g., a roof  120 , etc. 
     The sensor assembly  102  includes a housing  122  for the sensors  104 . The housing  122  is attachable to the vehicle  100 , e.g., to one of the body panels  118  of the vehicle  100 , e.g., the roof  120 . For example, the housing  122  may be shaped to be attachable to the roof  120 , e.g., may have a shape matching or following a contour of the roof  120 . The housing  122  may be attached to the roof  120 , which can provide the sensors  104  with unobstructed fields of view of areas around the vehicle  100 . The housing  122  may be formed of, e.g., plastic or metal. 
     With reference to  FIG.  2   , the housing  122  includes one or more housing panels  108  partially forming a chamber  124  inside the housing  122 , and the housing  122  includes the chamber  124  formed at least partially of the housing panels  108 . The housing panels  108  form an exterior of the housing  122  and are exposed to the ambient environment. 
     With reference to  FIG.  3   , the housing  122  includes the apertures  110 . The apertures  110  are holes in the housing  122  leading from the chamber  124  to the ambient environment. The apertures  110  are through the housing panels  108 . The apertures  110  are circular in shape. The housing  122  includes one aperture  110  for each of the sensors  104 . Each sensor  104  has a field of view defined by the sensor lens  106  through the respective aperture  110  through the respective housing panel  108 . Each sensor lens  106  can define an axis A on which the respective aperture  110  is centered, i.e., the axis A passes through a geometric center of a shape formed by the respective aperture  110 . The aperture  110  can have a circular shape that is orthogonal to the axis A. 
     The housing panels  108  can include one or more recessed portions  126 . The recessed portions  126  extend inward relative to the housing  122  from the rest of the respective housing panels  108 . Each recessed portion  126  can include one of the apertures  110 . The aperture  110  can be positioned at a most recessed point of the recessed portion  126 , i.e., a point farthest inward from the rest of the housing panel  108 . The recessed portion  126  can extend from the aperture  110  radially outwardly and axially away from the sensor lens  106  relative to the axis A defined by the sensor lens  106 . For example, the recessed portion  126  can have a frustoconical or pyramidal shape with an apex in the chamber  124  behind the aperture  110 . 
     The recessed portions  126  can be necessitated by the packaging of the components inside the housing  122  and the fields of view of the sensors  104 . The recessed portions  126  can increase a susceptibility of the sensor lenses  106  to having dead zones, so the benefits of the gap  114  described above can be especially helpful when the sensor  104  is located at one of the recessed portions  126 . 
     With reference to  FIG.  4   , the sensors  104  are positioned in the chamber  124 . The sensors  104  may detect the external world, e.g., objects and/or characteristics of surroundings of the vehicle  100 , such as other vehicles, road lane markings, traffic lights and/or signs, pedestrians, etc. For example, the sensors  104  may include radar sensors, scanning laser range finders, light detection and ranging (LIDAR) devices, and image processing sensors such as cameras. As cameras, the sensors  104  can detect electromagnetic radiation in some range of wavelengths. For example, the sensors  104  may detect visible light, infrared radiation, ultraviolet light, or some range of wavelengths including visible, infrared, and/or ultraviolet light. For example, the sensors  104  can be a charge-coupled devices (CCD), complementary metal oxide semiconductors (CMOS), or any other suitable type. For another example, the sensors  104  may be time-of-flight (TOF) cameras, which include a modulated light source for illuminating the environment and detect both reflected light from the modulated light source and ambient light to sense reflectivity amplitudes and distances to the scene. 
     The sensors  104  include the respective sensor lenses  106 . The sensor lenses  106  may be convex. Each sensor lens  106  may define the field of view of the respective sensor  104  through the aperture  110  through the housing panel  108 . Each sensor lens  106  defines the respective axis A, around which the sensor lens  106  is radially symmetric. The axis A extends along a center of the field of view of the respective sensor  104 . The axis A can be oriented horizontally, i.e., the sensor  104  can have a field of view extending laterally outward from the vehicle  100 . The sensor lens  106  can be recessed from the aperture  110  along the axis A, i.e., the sensor lens  106  is spaced from the aperture  110  along the axis A into the chamber  124 . 
     With reference to  FIG.  5   , the sensor assembly  102  includes a cleaning system  128 . The cleaning system  128  includes a pressure source  130 , a filter  132 , ducts  134 , and the air nozzles  112 . The pressure source  130  and the air nozzles  112  are fluidly connected to each other (i.e., fluid can flow from one to the other) through the ducts  134 . The pressure source  130 , the filter  132 , and the ducts  134  can be positioned inside the housing  122 , e.g., in the chamber  124 . 
     The pressure source  130  can be positioned to supply airflow to the air nozzles  112 , e.g., by forcing air through the ducts  134 . The pressure source  130  may be any suitable type of blower, e.g., a positive-displacement compressor such as a reciprocating, ionic liquid piston, rotary screw, rotary vane, rolling piston, scroll, or diaphragm compressor; a dynamic compressor such as an air bubble, centrifugal, diagonal, mixed-flow, or axial-flow compressor; a fan; or any other suitable type. The pressure source  130  can be positioned to draw air from an ambient environment outside the housing  122  and to blow the air into the ducts  134 . The pressure source  130  can be sized to provide air for cleaning multiple sensors  104 , e.g., two sensors  104 . 
     The filter  132  can remove solid particulates such as dust, pollen, mold, dust, and bacteria from air flowing through the filter  132 . The filter  132  may be any suitable type of filter, e.g., paper, foam, cotton, stainless steel, oil bath, etc. 
     The ducts  134  can be positioned to direct airflow from the pressure source  130  to the air nozzles  112 . For example, the ducts  134  can extend from the pressure source  130  to the respective air nozzles  112 , e.g., a first duct  134  to a first air nozzle  112  and a second duct  134  to a second air nozzle  112 . The ducts  134  may be, e.g., flexible tubes. 
     Returning to  FIG.  4   , the air nozzles  112  can be fixed relative to the respective sensor lenses  106 . The air nozzles  112  can be positioned to direct airflow out of the air nozzles  112  across the respective sensor lenses  106 , e.g., may be aimed at the respective sensor lenses  106  at an oblique angle. The air nozzles  112  can be positioned between the respective apertures  110  and the respective sensor lenses  106  along the respective axes A. The air nozzles  112  can be oriented to blow horizontally across the respective sensor lenses  106 , as illustrated in  FIG.  6   . The horizontal orientation of the air nozzles  112  can minimize interference from ambient airflow caused by movement of the vehicle  100 . For the sensor  104  located on a lateral side of the housing  122 , the air nozzles  112  can be oriented to blow horizontally in a vehicle-rearward direction. 
     With reference again to  FIG.  5   , the cleaning system  128  can further include a reservoir  136 , a pump  138 , valves  140 , supply lines  142 , and liquid nozzles  144 . The reservoir  136 , the pump  138 , and the liquid nozzles  144  are fluidly connected to each other, i.e., fluid can flow from one to the other, via the supply lines  142 . The cleaning system  128  distributes washer fluid stored in the reservoir  136  to the liquid nozzles  144 . “Washer fluid” is any liquid stored in the reservoir  136  for cleaning. The washer fluid may include solvents, detergents, diluents such as water, etc. 
     The reservoir  136  may be a tank fillable with liquid, e.g., washer fluid for window cleaning. The reservoir  136  may be disposed in a front of the vehicle  100 , e.g., in an engine compartment forward of a passenger cabin, or may be disposed in the housing  122 . The reservoir  136  may store the washer fluid only for supplying the sensor assembly  102  or also for other purposes, such as supply to the windshield. 
     The pump  138  may force the washer fluid through the supply lines  142  to the liquid nozzles  144  with sufficient pressure that the washer fluid sprays from the liquid nozzles  144 . The pump  138  is fluidly connected to the reservoir  136 . The pump  138  may be attached to or disposed in the reservoir  136 . The pump  138  may be sized to provide washer fluid to multiple liquid nozzles  144 , e.g., two liquid nozzles  144 . 
     Each valve  140  is positioned and operable to control fluid flow from the pump  138  to one of the liquid nozzles  144 . Specifically, fluid from the supply line  142  from the pump  138  must flow through one of the valves  140  to reach the respective supply line  142  providing fluid to the respective liquid nozzle  144 . The valves  140  control flow by being actuatable between an open position permitting flow and a closed position blocking flow from the incoming to the outgoing of the supply lines  142 . The valves  140  can be solenoid valves. As a solenoid valve, each valve  140  includes a solenoid and a plunger. Electrical current through the solenoid generates a magnetic field, and the plunger moves in response to changes in the magnetic field. The solenoid moves the plunger between a position in which the valve  140  is open and a position in which the valve  140  is closed. 
     The supply lines  142  extend from the pump  138  to the liquid nozzles  144 . The supply lines  142  may be, e.g., flexible tubes or hoses. 
     With reference to  FIG.  6   , the liquid nozzles  144  are fixed relative to the respective sensor lenses  106 . The liquid nozzles  144  can be positioned to direct washer fluid out of the liquid nozzles  144  onto the respective sensor lenses  106 , e.g., may be aimed at the respective sensor lenses  106  at an oblique angle. The liquid nozzles  144  can be oriented to spray across the respective sensor lenses  106 , e.g., oriented so that a center of the spray intersects the axis A defined by the sensor lens  106 . 
     The liquid nozzle  144  can be positioned between the aperture  110  and the sensor lens  106  along the axis A. More specifically, the liquid nozzle  144  can be positioned in the gap  114  between the aperture  110  and the sensor lens  106 . The liquid nozzle  144  can be positioned circumferentially relative to the axis A less than 90° from the air nozzle  112 . For example, as shown in  FIG.  6   , an angle around the axis A between the center of the air nozzle  112  and the center of the liquid nozzle  144  is approximately 45°. The circumferential position of the liquid nozzle  144  can direct the spray from the liquid nozzle  144  into the gap  114 , like the airflow from the air nozzle  112 . The spray is therefore less likely to be carried to other sensor lenses  106  of the sensor assembly  102 . 
     Each air nozzle  112  can include an outlet  146  having a slot shape, i.e., that is significantly longer in a first direction than in an orthogonal second direction. The slot shape of the outlet  146  can be elongated parallel to the sensor lens  106 , i.e., elongated in a plane orthogonal to the axis A defined by the sensor lens  106 . The outlet  146  can be elongated along a circumferential path around the axis A at a constant radius from the axis A. For example, the outlet  146  can be formed by two walls extending along the direction of elongation and two walls extending perpendicular to the direction of elongation. The slot shape oriented parallel to the sensor lens  106  can provide complete coverage of the sensor lens  106  by the airflow from the air nozzle  112 . 
     With reference to  FIG.  7   , the aperture  110  and the sensor lens  106  define the gap  114 . The gap  114  can extend circumferentially around the axis A from the air nozzle  112  to the air nozzle  112 , e.g., from one end of the slot shape of the air nozzle  112  away from the air nozzle  112  around the axis A to the other end of the slot shape of the air nozzle  112 . The gap  114  can be positioned on an opposite lateral side of the sensor lens  106  from the air nozzle  112 . The gap  114  can further be positioned in an upward direction from the sensor lens  106  and in a downward direction from the sensor lens  106 . The extent of the gap  114  above and below the sensor lens  106  can help provide smooth airflow across an entirety of the sensor lens  106 . The gap  114  can have a constant axial width between the sensor lens  106  and the aperture  110  circumferentially around the axis A from the air nozzle  112  back to the air nozzle  112 . 
     Returning to  FIG.  4   , the gap  114  is positioned to direct airflow from the air nozzle  112  (as well as spray from the liquid nozzle  144 ) into the chamber  124 . For example, the space axially between the aperture  110  and the sensor lens  106 , i.e., the space within the gap  114 , can be open to the chamber  124 , as shown in  FIG.  4   . For another example, the gap  114  can be an inlet to tubing (not shown) leading to the chamber  124 . The chamber  124  can be structured as a “wet” environment. For example, the sensors  104  positioned in the chamber  124 , as well as other components in the chamber  124 , can be sealed, e.g., waterproof. The sensors  104 , as well as other components in the chamber  124 , can have exteriors formed of materials not prone to rust, e.g., plastic. 
     With reference to  FIG.  8   , the housing  122  can include a lower surface  148 . The chamber  124  can be formed in part by the lower surface  148 . The lower surface  148  can be positioned between the rest of the chamber  124  and, e.g., the roof  120  of the vehicle  100 . The housing  122 , e.g., the lower surface  148 , can include one or more drainage channels  150  positioned inside the chamber  124 . The drainage channels  150  can be shaped to direct fluid to outside the housing  122 . For example, the drainage channels  150  can be sloped downward to exit points from the housing  122 . 
     The disclosure has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. The adjectives “first” and “second” are used throughout this document as identifiers and are not intended to signify importance, order, or quantity. Many modifications and variations of the present disclosure are possible in light of the above teachings, and the disclosure may be practiced otherwise than as specifically described.