Patent Application
20180265049
Autonomous vehicles include a variety of sensors. Some sensors detect internal states of the vehicle, for example, wheel speed, wheel orientation, and engine and transmission variables. Some sensors detect the position or orientation of the vehicle, for example, 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 magnetometers. Some sensors detect the external world, for example, radar sensors, scanning laser range finders, light detection and ranging (LIDAR) devices, and image processing sensors such as cameras. A LIDAR device detects distances to objects by emitting laser pulses and measuring the time of flight for the pulse to travel to the object and back. Some sensors are communications devices, for example, vehicle-to-infrastructure (V2I) or vehicle-to-vehicle (V2V) devices.
An apparatus 32 includes a sensor 54 supported by a sensor arm 52, a fan 72 mounted in a position that is fixed relative to the sensor 54, and a duct 74. The sensor 54 includes a cylindrical window 62 defining an axis A. The duct 74 is positioned to deliver air from the fan 72 toward the cylindrical window 62. The duct 74 has an opening 76 extending along an arc of a circle centered on the axis A.
The apparatus 32 may also include the sensor arm 52 extensible from a pillar 36, 38, 40 of a vehicle 30. Additionally, the apparatus 32 may include the pillar 36, 38, 40 of the vehicle 30, and the pillar 36, 38, 40 may extend from a first end 98 at a bottom of a windshield 44 to a second end 100 at a top of the windshield 44, and the sensor arm 52 may be attached to the pillar 36, 38, 40 spaced from the first end 98 and from the second end 100. Additionally, the fan 72 may be disposed beneath the sensor 54.
The opening 76 may be positioned to create an air curtain across the cylindrical window 62 when the fan 72 is operating.
The opening 76 may extend at least 180° about the axis A.
The opening 76 may have a width W that is substantially constant along the arc of the circle.
The apparatus 32 may also include a sprayer 86 coupled to the sensor 54. Additionally, the sprayer 86 may be ring-shaped. Additionally, the cylindrical window 62 has a diameter, and the sprayer 86 may have a diameter larger than the diameter of the cylindrical window 62. Additionally, the sprayer 86 may have a plurality of sprayer nozzles 88 directed toward the cylindrical window 62.
In an alternative embodiment, the apparatus 32 includes the sensor 54 supported by the sensor arm 52, the fan 72 mounted in a position that is fixed relative to the sensor 54, and the duct 74. The sensor 54 has the cylindrical window 62 defining the axis A. The duct 74 is positioned to deliver air from the fan 72 toward the cylindrical window 62. The duct 74 has a plurality of air nozzles 78 each positioned on the circle centered on the axis A.
The apparatus 32 may also include the sensor arm 52 extensible from the pillar 36, 38, 40 of the vehicle 30. Additionally, the apparatus 32 may include the pillar 36, 38, 40 of the vehicle 30, and the pillar 36, 38, 40 may extend from the first end 98 at the bottom of the windshield 44 to the second end 100 at the top of the windshield 44, and the sensor arm 52 may be attached to the pillar 36, 38, 40 spaced from the first end 98 and from the second end 100. Additionally, the fan 72 may be disposed beneath the sensor 54.
The apparatus 32 may also include the sprayer 86 coupled to the sensor 54. Additionally, the sprayer 86 may be ring-shaped. Additionally, the cylindrical window 62 has a diameter, and the sprayer 86 may have a diameter larger than the diameter of the cylindrical window 62. Additionally, the sprayer 86 may have the plurality of sprayer nozzles 88 directed toward the cylindrical window 62.
The apparatus 32 cleans the sensor 54 and may thus allow the sensor 54 to more accurately detect the external environment. The sensor 54 is positioned relative to the rest of the vehicle 30 so as not cause significant drag or increase a height of the vehicle 30 by being located on a roof of the vehicle 30, while still maintaining a wide field of view for the sensor 54. The apparatus 32 is positioned relative to the rest of the vehicle 30 so that the apparatus 32 will not block the field of view of the sensor 54 nor of a human driver of the vehicle 30 who is looking through the windshield 44 or a window 46 of the vehicle 30.
With reference to
The windshield 44 and windows 46 may be formed of any suitably durable transparent material, including glass such as laminated, tempered glass or plastic such as Plexiglas or polycarbonate. The windshield 44 is located adjacent the A pillars 36.
The vehicle 30 may include side-view mirrors 106. The side-view mirrors 106 may be located on the front doors 50 or on the body 34 near the bottom of the windshield 44. The side-view mirrors 106 may be visible to a human driver through the windows 46 and provide a reflected view of a vehicle-rearward direction to the driver.
With continued reference to
With reference to
The sensor 54 may be designed to detect features of the outside world; for example, the sensor 54 may be a radar sensor, a scanning laser range finder, a light detection and ranging (LIDAR) device, or an image processing sensor such as a camera. In particular, the sensor 54 may be a LIDAR device. A LIDAR device detects distances to objects by emitting laser pulses and measuring the time of flight for the pulse to travel to the object and back.
With reference to
With reference to
With reference to
The sprayer 86 may have the plurality of sprayer nozzles 88 directed toward the cylindrical window 62 and a channel 90 extending through the sprayer 86 and feeding into the sprayer nozzles 88. The sprayer nozzles 88 may be spaced circumferentially about the sensor 54. The sprayer nozzles 88 may be located on a circle centered on the axis A. The sprayer nozzles 88 may be spaced circumferentially evenly completely or partially about the axis A, or the sprayer nozzles 88 may be more closely spaced on a vehicle-forward side of the sensor 54 than on a vehicle-rearward side of the sensor 54.
With reference to
With reference to
The inlet 80 may contain an air filter 84. The air filter 84 may extend across the inlet 80 and may cover a cross-section of the air filter 84 so that air cannot pass around the air filter 84 through the inlet 80. The air filter 84 may be formed of fibrous materials that remove solid particulates, e.g., dust, smog, pollen, etc., from the air.
The fan 72 is mounted in a position that is fixed relative to the sensor 54, for example, beneath the sensor 54. The fan 72 may be disposed between the sensor 54 and the side-view mirror 106. The fan 72 may include an impeller having vanes (not shown) that, when the impeller is rotated, pull air from the inlet 80 and push air toward the opening 76. The fan 72 may be a centrifugal fan (as shown in
With continued reference to
The duct 74 is positioned to deliver air from the fan 72 toward the cylindrical window 62. The duct 74 may extend about the axis A. The duct 74 may extend around the drive motor 70. The duct 74 may have a width measured radially with respect to the axis A. The width of the duct 74 may narrow from the fan 72 to the opening 76 or the air nozzles 78.
In a first example of the apparatus 32, the duct 74 may have the opening 76 extending along the arc of the circle centered on the axis A. An “arc of a circle” is a mathematical term referring to a connected section of a circumference of a circle, i.e., a partial circle. The opening 76 may extend fully about the axis A, i.e., 360°, or the opening 76 may extend partially about the axis A. For example, the opening 76 may extend at least 180° about the axis A. The opening 76 has the width W that may be substantially constant along the arc of the circle, that is, difference in air flow through the opening 76 at different points about the circle is negligible. The opening 76 is positioned to create an air curtain across the cylindrical window 62 when the fan 72 is operating. An “air curtain” is a layer of moving air. In other words, the airflow from the opening 76 travels vertically across the cylindrical window 62 and substantially covers, that is, covers most of, the cylindrical window 62 or the viewing portion 70 of the cylindrical window 62. “Across” means from one side of something to the other side. The air curtain serves as a barrier and may deflect debris or other potential obstructions from contacting the cylindrical window 62.
In a second example of the apparatus 32, the duct 74 may have the plurality of air nozzles 78 each positioned on a circle centered on the axis A. The air nozzles 78 may be spaced circumferentially about the sensor 54. The air nozzles 78 may be spaced evenly about the axis A or partially about the axis A, or the air nozzles 78 may be more closely spaced on a vehicle-forward side of the sensor 54 than on a vehicle-rearward side of the sensor 54. The air nozzles 78 may be positioned to create an air curtain across the cylindrical window 62 when the fan 72 is operating. In other words, the airflow from the air nozzles 78 travels vertically across the cylindrical window 62, that is, from the bottom edge 64 to the top edge 66, and substantially covers the cylindrical window 62 or the viewing portion 70 of the cylindrical window 62.
In operation, when the vehicle 30 is in operation and traveling forward, the drive motor 70 drives the fan 72. The fan 72 pulls air through the air filter 84 and the inlet 80 and pushes the air into the duct 74. The duct 74 redirects the air through the opening 76 or the air nozzles 78. The air flows continuously across the cylindrical window 62. The continuous airflow may deflect dirt, particles, etc. from contacting the cylindrical window 62, keeping the cylindrical window 62 clear and facilitating the operation of the sensor 54. If an obstruction does land and stick on the cylindrical window 62, the sprayer 86 may be used to wash away the obstruction.
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. 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.
