Sensor assembly

Abstract

The present disclosure provides a "sensor assembly." A sensor assembly includes: a sensor window; a heat sink including a plurality of fins; and an air duct. The heat sink is fixed relative to the sensor window. The air duct is positioned to direct airflow between the fins and across the sensor window. The sensor assembly may include a motor and / or a circuit board fixed relative to the sensor window. The heat sink may be directly connected to the motor and / or the circuit board via a thermal conductor.

Description

Technical Field

[0001] The present invention relates to the field of vehicle sensor assemblies. Background Art

[0002] Autonomous vehicles include a variety of sensors. Some sensors detect the internal state of the vehicle, such as wheel speed, wheel orientation, and engine and transmission variables. Some sensors detect the position or orientation of the vehicle, such as global positioning system (GPS) sensors; accelerometers such as piezoelectric or microelectromechanical systems (MEMS); gyroscopes such as rate, ring laser, or fiber gyroscopes; inertial measurement units (IMUs); and magnetometers. Some sensors detect the external world, such as radar sensors, scanning laser rangefinders, light detection and ranging (LIDAR) devices, and image processing sensors such as cameras. LIDAR devices detect the distance to an object by emitting laser pulses and measuring the flight time of the pulses to the object and back. Some sensors are communication devices, such as vehicle-to-infrastructure (V2I) devices or vehicle-to-vehicle (V2V) devices. Summary of the Invention

[0003] A sensor assembly includes a sensor window, a heat sink including a plurality of fins, and an air duct. The heat sink is fixed relative to the sensor window. The air duct is positioned to direct airflow between the fins and across the sensor window.

[0004] The sensor assembly may include a circuit board fixed relative to the sensor window, and the heat sink may be directly connected to the circuit board via a thermal conductor.

[0005] The sensor assembly may include a motor fixed relative to the sensor window, and the heat sink may be directly connected to the motor via a thermal conductor. The sensor assembly may include a sensor rotatably coupled to the motor. The sensor may be a LIDAR sensor.

[0006] A heat sink may be positioned below the sensor window.

[0007] The fins may be oriented vertically.

[0008] The air duct may include a plurality of nozzles. Each pair of adjacent fins may define a gap therebetween, and each nozzle may be positioned to direct airflow through one of the gaps.

[0009] The sensor window may have a cylindrical shape. The sensor window may define an axis, and the fins may be radially elongated relative to the axis. The sensor window may define an axis, and the heat sink may be annularly arranged around the axis.

[0010] The sensor assembly may include a compressor fixed relative to the sensor window, and the air duct may be positioned to receive airflow from the compressor.

[0011] The air ducts may be positioned to form an air curtain across the sensor window.

[0012] The air duct may include a slot extending beneath the plurality of fins.

[0013] The fins may be exposed to the surrounding environment.

[0014] The sensor window may be coupled to the vehicle, and the plurality of fins may be positioned to receive airflow between the fins from the forward movement of the vehicle.

[0015] The heat sink may have a higher thermal conductivity than the sensor window. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a perspective view of a vehicle including a sensor assembly.

[0017] Figure 2 This is a perspective exploded view of one of the sensor assemblies.

[0018] Figure 3 is a side view of the sensor assembly.

[0019] Figure 4 is a top view of a sensor assembly with exemplary air ducts.

[0020] Figure 5 is a top view of a sensor assembly with another exemplary air duct. DETAILED DESCRIPTION

[0021] The sensor assembly 54 includes a sensor window 84, a heat sink 90 including a plurality of fins 94, and an air duct 104. The heat sink 90 is fixed relative to the sensor window 84. The air duct 104 is positioned to direct airflow between the fins 94 and across the sensor window 84.

[0022] Heat sink 90 helps dissipate heat generated within sensor assembly 54. Air duct 104 is positioned to generate airflow so that heat sink 90 can dissipate more heat than without airflow, and air duct 104 is positioned to generate the same airflow across sensor window 84 of sensor assembly 54, thereby forming an air curtain that can reduce debris impacting sensor window 84. By using the same airflow for heat dissipation and cleaning, sensor assembly 54 is more efficient. Therefore, air duct 104 can allow sensor 68 to more accurately detect the external environment.

[0023] refer to Figure 1The body 32 of the vehicle 30 may include an A-pillar 34, a B-pillar 36, a C-pillar 38, and a roof rail 40. The A-pillar 34 may extend between a windshield 42 and windows 43, and extend from a first end 44 at the bottom of the windshield 42 to a second end 46 at the top of the windshield 42. (The adjectives "first" and "second" are used throughout this document as identifiers and are not intended to indicate importance or order.) The B-pillar 36 may extend between the windows 43 of adjacent doors 48. The C-pillar 38 may extend between the windows 43 and the rear window (not shown). If the vehicle 30 is, for example, an SUV, a crossover, a minivan, or a station wagon, the body 32 may also include a D-pillar (not shown). In this case, the C-pillar 38 extends between the windows 43 of the rear doors 48 and the left and right rear windows 43, and the D-pillar extends between the right and left rear windows 43 and the rear window. The roof rail 40 extends along the window 43 from the A-pillar 34 to the B-pillar to the C-pillar.

[0024] The windshield 42 , the windows 43 and the rear window may be formed of any suitable durable transparent material, including glass such as laminated tempered glass or plastic such as Plexiglas or polycarbonate. The windshield 42 is located adjacent the A-pillars 34 .

[0025] The vehicle 30 may include side view mirrors 50. The side view mirrors 50 may be located on the front doors 48 or on the body 32 near the bottom of the windshield 42. The side view mirrors 50 may be visible to a human driver through the window 43 and provide the driver with a reflected view of the vehicle in a rearward direction.

[0026] Continue to refer Figure 1 , a sensor arm 52 extends from one of the pillars 34, 36, 38 of the vehicle 30 (e.g., the A-pillar 34) to the sensor assembly 54. The sensor arm 52 can be located between the ends 44, 46 of the A-pillar 34, i.e., spaced from the bottom of the windshield 42 and from the top of the windshield 42, i.e., spaced from the first end 44 and from the second end 46. The sensor arm 52 can be attached to a base 56 of the sensor assembly 54. The sensor arm 52 can have a tubular or other hollow shape, i.e., a cavity can extend through the sensor arm 52. The cavity can allow wiring, tubing, etc. to pass through the sensor arm 52 while being isolated from the outside environment.

[0027] refer to Figure 1-Figure 3, the sensor assembly 54 is supported by the sensor arm 52. The sensor assembly 54 includes a housing 58. The housing 58 may have a cylindrical shape having a top cover 60, a base 56, and a sensor window 84. The top cover 60 is located above the sensor window 84, i.e., in an upward direction from the vehicle, and the base 56 is located below, i.e., in a downward direction from the sensor window 84 along the vehicle. The housing 58 has a side surface 64 that includes the outer side of the sensor window 84 and the circumferentially extending sides of the top cover 60 and the base 56. The side view mirrors 50 may be located below the housing 58, i.e., in a downward direction from the housing 58 along the vehicle, and each base 56 has a bottom surface 62 that faces each side view mirror. The cylindrical shape of the housing 58 defines an axis A that extends through the center of the housing 58. The axis A is oriented vertically relative to the vehicle 30.

[0028] refer to Figure 2 Sensor 68 is positioned inside housing 58 and is attached to and supported by sensor arm 52. Sensor 68 can be designed to detect features in the external environment; for example, sensor 68 can be a radar sensor, a scanning laser rangefinder, a light detection and ranging (LIDAR) device, or an image processing sensor such as a camera. In particular, sensor 68 can be a LIDAR device. LIDAR devices detect the distance to an object by emitting laser pulses at a specific wavelength and measuring the flight time of the pulses to the object and back.

[0029] Housing 58 may contain: a rotating head 66; a sensor 68 including a laser 70 and a receiver 72; an encoder 74; a slip ring 76; a motor 78; an insulator 80; and a circuit board 82. Circuit board 82, insulator 80, and motor 78 may be fixed relative to housing 58. Encoder 74, slip ring 76, and sensor 68 are fixed relative to each other and rotatably coupled to motor 78. Motor 78 is configured to rotate sensor 68 about a vertical axis A to provide horizontal 360° coverage. Insulator 80 may be positioned between circuit board 82 and motor 78 and may reduce heat traveling between circuit board 82 and motor 78.

[0030] refer to Figure 2 and Figure 3Sensor window 84 is supported by sensor arm 52 and attached thereto, such as via base 56. Sensor window 84 can be cylindrical and can further define an axis A. Sensor window 84 extends about axis A. Sensor window 84 can extend completely about axis A, i.e., 360°, or partially about axis A. Sensor window 84 extends along axis A from a bottom edge 86 to a top edge 88. Sensor window 84 has a diameter. If present, the diameter of sensor window 84 can be the same as the remainder of side surface 64; in other words, sensor window 84 can be flush or substantially flush with side surface 64. "Substantially flush" means that the joint between sensor window 84 and the remainder of side surface 64 does not cause turbulence in air flowing along side surface 64. At least some of sensor window 84 is transparent to any medium capable of being detected by sensor 68. For example, if sensor 68 is a LIDAR device, sensor window 84 is transparent to visible light having a wavelength generated by laser 70.

[0031] refer to Figure 2-Figure 5 , the heat sink 90 can be attached (e.g., fastened, adhered, etc.) to the rest of the sensor assembly 54 and fixed relative to the sensor window 84. For example, the heat sink 90 can be fastened by one or more connecting rods 92 extending through the base 56. The heat sink 90 can be positioned below the sensor window 84 and annularly surround the base 56. The heat sink 90 can be separate from the base 56, or it can touch the base 56. If the heat sink 90 is separate from the base 56, the space between the heat sink 90 and the base 56 can be filled with a thermal gap filler, such as thermal grease or a silicone-coated gap filler. The heat sink 90 can be exposed to the ambient environment; that is, no cover extends over the heat sink 90.

[0032] Heat sink 90 may be a material with high thermal conductivity, such as aluminum or copper. Thermal conductivity is the property of a material to transfer heat. Heat sink 90 has a higher thermal conductivity than other components of sensor assembly 54, such as housing 58 and sensor window 84.

[0033] refer to Figure 2 , the heat sink 90 is directly connected to the circuit board 82 and / or the motor 78 via a connecting rod 92. The connecting rod 92 is a thermal conductor. For the purposes of this disclosure, a thermal conductor is defined as a component having a high thermal conductivity, substantially at least as high as the thermal conductivity of the heat sink 90.

[0034] refer to Figure 2-Figure 5, the radiator 90 is arranged in an annular shape around the axis A. The radiator 90 includes a plurality of fins 94. The fins 94 are oriented and extended vertically, i.e., parallel to the axis A, and oriented and extended radially, i.e., away from the axis A. Each fin 94 can have, for example, a rectangular shape. The fins 94 are exposed to the surrounding environment. Each pair of adjacent fins 94 defines a gap 96 therebetween. The gap 96 allows airflow between the fins 94 and allows heat to flow from the fins 94 to the ambient air. The plurality of fins 94 (e.g., the fins 94 on the vehicle front side of the radiator 90) can be positioned to receive airflow between the fins from the forward movement of the vehicle 30.

[0035] refer to Figure 1 , the air system 98 includes a compressor 100, a supply line 102, and an air duct 104. The compressor 100 and the air duct 104 are fluidly connected to each other via the supply line 102 (ie, fluid can flow from one to the other).

[0036] The compressor 100 is fixed relative to the sensor window 84 and can be located in the vehicle 30, spaced apart from the sensor assembly 54. The compressor 100 increases the pressure of the gas by reducing the volume of the gas or by squeezing additional gas into a constant volume. The compressor 100 can be any suitable type of compressor, for example, 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 a bubble, centrifugal, diagonal, mixed flow, or axial flow compressor; or any other suitable type.

[0037] A supply line 102 extends from the compressor 100 to an air duct 104. The supply line 102 may be, for example, a flexible pipe.

[0038] refer to Figure 2-Figure 5 , duct 104 is positioned to receive airflow from compressor 100; for example, duct 104 may include an inlet 106 attached to supply line 102. Duct 104 may define an annular cavity 108 located below radiator 90. The diameter of duct 104 may be greater than the diameter of sensor window 84.

[0039] Duct 104 is positioned to direct airflow between fins 94 and across sensor window 84; in other words, a single pathline of the generated airflow from duct 104 extends between fins 94 and from one side of sensor window 84 to the other (e.g., from bottom edge 86 to top edge 88). "Across" means from one side of something to the other. A "pathline" is defined as the trajectory of individual fluid particles through the velocity vector field of the fluid. The airflow may form an air curtain across sensor window 84; that is, duct 104 is positioned to form an air curtain across sensor window 84. An "air curtain" is a layer of moving air.

[0040] refer to Figure 4 and Figure 5 The air duct 104 may include one or more openings 110, 112 directed upwardly from the cavity 108. For example, the air duct 104 may include a slot 110 extending below a plurality of fins 94 or all of the fins 94, such as Figure 4 As shown in FIG. The air flowing out of the slot 110 travels upward, is separated by the fins 94 into the gap 96, and continues from the fins 94 through the sensor window 84. For another example, the air duct 104 may include a plurality of nozzles 112, such as Figure 5 Each nozzle 112 may be positioned to direct airflow through one of the gaps 96; for example, each nozzle 112 may be positioned below one of the gaps 96. Air flowing from nozzles 112 travels upward between fins 94 and then through sensor window 84.

[0041] During operation, motor 78 rotates sensor 68 about axis A while laser 70 emits light pulses and receiver 72 receives reflected light bursts. Circuit board 82 processes the signals from sensor 68. Sensor assembly 54, particularly motor 78 and circuit board 82, generates heat during operation. Some of this heat is conducted to heat sink 90 via connecting rod 92. Compressor 100 blows air through supply line 102 into air duct 104 and through openings 110 and 112. The airflow travels through heat sink 90, absorbing heat from the surfaces of fins 94, and then passes through sensor window 84. The airflow through sensor window 84 reduces the amount of debris that can impact sensor window 84.

[0042] The present disclosure has been described in an illustrative manner, and it should be understood that the terminology used is intended to be words of description rather than limitation in nature. Many modifications and variations of the present disclosure are possible in light of the above teachings, and the present disclosure may be practiced in other ways than specifically described.

[0043] According to the present invention, a sensor assembly is provided, comprising: a sensor window; a heat sink including a plurality of fins, the heat sink being fixed relative to the sensor window; and an air duct positioned to direct airflow between the fins and across the sensor window.

[0044] According to one embodiment, the above invention further features a circuit board fixed relative to the sensor window, wherein the heat sink is directly connected to the circuit board via a thermal conductor.

[0045] According to one embodiment, the above invention also features a motor that is fixed relative to the sensor window, wherein the heat sink is directly connected to the motor via a thermal conductor.

[0046] According to one embodiment, the above invention also features a sensor rotatably coupled to the motor.

[0047] According to one embodiment, the sensor is a LIDAR sensor.

[0048] According to one embodiment, the heat sink is positioned below the sensor window.

[0049] According to one embodiment, the fins are vertically oriented.

[0050] According to one embodiment, the air duct comprises a plurality of nozzles.

[0051] According to one embodiment, each pair of adjacent fins defines a gap therebetween, and each nozzle is positioned to direct airflow through one of the gaps.

[0052] According to one embodiment, the sensor window has a cylindrical shape.

[0053] According to one embodiment, the sensor window defines an axis and the fins are radially elongated relative to said axis.

[0054] According to one embodiment, the sensor window defines an axis and the heat sink is annularly arranged around said axis.

[0055] According to one embodiment, the above invention further features a compressor that is fixed relative to the sensor window, wherein the air duct is positioned to receive air flow from the compressor.

[0056] According to one embodiment, the air ducts are positioned to form an air curtain across the sensor window.

[0057] According to one embodiment, the air duct comprises a slot extending below the plurality of fins.

[0058] According to one embodiment, the fins are exposed to the surrounding environment.

[0059] According to one embodiment, the sensor window may be coupled to a vehicle, and the plurality of fins may be positioned to receive airflow between the fins from the forward movement of the vehicle.

[0060] According to one embodiment, the heat sink has a higher thermal conductivity than the sensor window.

Claims

1. A sensor assembly comprising: sensor window; a heat sink comprising a plurality of fins, the heat sink being fixed relative to the sensor window; an air duct positioned to direct airflow between the fins and across the sensor window; a motor, the motor being fixed relative to the sensor window, wherein the heat sink is directly connected to the motor via a thermal conductor; as well as A sensor is rotatably coupled to the motor.

2. The sensor assembly of claim 1 , further comprising a circuit board fixed relative to the sensor window, wherein the heat sink is directly connected to the circuit board via a thermal conductor.

3. The sensor assembly of claim 1, wherein the heat sink is positioned below the sensor window. The sensor assembly of claim 1 , wherein the fins are vertically oriented. The sensor assembly of claim 1 , wherein the air duct comprises a plurality of nozzles.

6. The sensor assembly of claim 5, wherein each pair of adjacent fins defines a gap therebetween, and each orifice is positioned to direct airflow through one of the gaps.

7. The sensor assembly of claim 1, wherein the sensor window has a cylindrical shape.

8. The sensor assembly of claim 7, wherein the sensor window defines an axis and the fins are radially elongated relative to the axis.

9. The sensor assembly of claim 7, wherein the sensor window defines an axis and the heat sink is annularly arranged about the axis. 10 . The sensor assembly of claim 1 , further comprising a compressor fixed relative to the sensor window, wherein the air duct is positioned to receive airflow from the compressor.

11. The sensor assembly of claim 1, wherein the air duct comprises a slot extending below a plurality of the fins.

12. The sensor assembly of claim 1, wherein the sensor window is attachable to a vehicle, and the plurality of fins are positioned to receive airflow between the fins from forward movement of the vehicle.

13. The sensor assembly of claim 1, wherein the heat sink has a higher thermal conductivity than the sensor window.

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