Patent Description:
However, these vehicles are often subjected to environmental elements such as rain, snow, dirt, condensation, etc., which can cause a buildup of debris and contaminants on these sensors. Typically, the sensors include a cover to protect the internal sensor components of the sensors from the debris and contaminants, but over time, the cover itself may become dirty. As such, the functions of the internal sensor components may be impeded as signals transmitted and received by the internal sensor components are blocked by the debris and contaminants.

<CIT> discloses an environmental protection system that features a clear spinning curved volumetric enclosure to shed and throw off environmental contaminants such as rain, fog and dust that would affect a sensor image. The described design is especially suitable for cameras with extremely wide fields of view, such as panoramic or immersive cameras.

<CIT> discloses an environmental shroud and a camera assembly. In one embodiment, the camera assembly includes a camera housing which has a mounting cap attached to sidewalls to which is attached an optical surface. The camera housing encloses a camera system. An environmental shroud is attached to the camera housing and includes a plurality of vertical strips situated concentrically with the camera housing and with each other with gaps being present between the vertical strips and between the camera housing. In another embodiment, the environmental shroud is a turbine and includes a plurality of vertical blades situated concentrically with the camera housing, whereby wind which contacts the blades causes the shroud to rotate and generate a centrifugal force effective to remove moisture from the camera housing.

<CIT> discloses a vehicle that includes a light detection and ranging device (LIDAR).

Aspects of the disclosure are directed to a system for preventing particle buildup on a sensor housing in line with claim <NUM>.

In some instances, the first surface may be coated in a hydrophobic coating.

In some instances, the position adjacent to the first surface may be a leading position relative to the first surface during rotation of the sensor housing.

In some examples, the airflow may be configured to alter a trajectory of a particle. In some examples, the airflow may be configured to alter trajectories' of particles having different sizes by different amounts.

In some instances, the sensor housing may be configured to generate a centripetal force on one or more particles in contact with the sensor housing. In some examples, the centripetal force is generated by the motor rotating the sensor housing around the axis of rotation.

In some instances, the spoiler edge may be configured to cast a shadow region on the sensor housing.

In some instances, the spoiler edge may be configured to cast a shadow region on the first surface.

In some instances, the first surface may be substantially flat.

In some instances, the system may further include a vehicle, wherein the sensor is mounted to the vehicle.

In some instances, the system may further comprise a motor configured to rotate the sensor around the axis of rotation.

The present technology is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements including:.

This technology relates to preventing the buildup of particles on one or more portions of a sensor housing to assure adequate operation. For instance, a sensor may include a housing to protect the internal sensor components from particles of water, dust, dirt, etc., as well as other contaminants, such as insects. However, the housing itself may become covered by particles over time. As such, the functions of the internal sensor components may be impeded as signals transmitted and received by the internal sensor components may be blocked by the buildup of particles. To address this, a spoiler edge may be incorporated into or attached to the sensor housing. The spoiler edge may alter the path of the particles to prevent the particles from building up on areas of the sensor housing where signals may be transmitted and/or received.

A vehicle may have one or more sensors to detect objects external to the vehicle such as other vehicles, obstacles in the roadway, traffic signals, signs, trees, etc. For example, the vehicle <NUM>, as shown in <FIG>, may include lasers, sonar, radar, cameras and/or any other detection devices that capture images and record data which may be processed by computing devices within the vehicle. The vehicle's sensors, such as LIDAR, radar, cameras, sonar, or other such imaging sensors, may capture images and detect objects and their characteristics such as location, orientation, size, shape, type, direction and speed of movement, etc. Images may include the raw (i.e., unprocessed) data captured by the sensors and/or pictures and videos captured by camera sensors. Images may also include processed raw data. For instance, the raw data from the sensors and/or the aforementioned characteristics can be quantified or arranged into a descriptive function or vector for processing by the computing devices. The images may be analyzed to determine the vehicle's location, and to detect and respond to objects when needed.

The sensors may be arranged around the vehicle's exterior or interior. For example, housings <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may include, for example, one or more LIDAR devices. The sensors may also be incorporated into the typical vehicle components, such as tail lights/turn signal lights <NUM> and/or side view mirrors <NUM>. In some instances one or more laser, radar, sonar, camera and/or other such imaging sensors may be mounted on the roof, such as housings <NUM> and <NUM>.

A vehicle sensor may be comprised of internal sensor components and a housing for housing the internal sensor components. For instance, the sensor housing <NUM>, which may be compared to housing <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, may be configured such that it has a domed shaped top portion <NUM> with a side wall <NUM>, such that the housing is in the shape of a frustum, as shown in <FIG>. Although the sensor housing is shown in the shape of a frustum, the sensor housing may be configured in various shapes and sizes, such as spheres, cylinders, cuboids, cones, prisms, pyramids, cubes, etc., or any combination of such shapes. The sensor housing <NUM> may be comprised of materials such as plastic, glass, polycarbonate, polystyrene, acrylic, polyester, etc..

The sensor housing may include a surface, such as a housing window constructed at a certain location on the sensor housing such that the internal sensor components may transmit and receive one or more signals through the housing window. For instance, the side wall <NUM> of the sensor housing <NUM> may include a flat portion <NUM> in which housing window <NUM> is incorporated to allow signals (not shown) from internal sensor components <NUM> to penetrate the sensor housing <NUM>, as further shown in <FIG>. Although, the housing window <NUM> is shown as being circular in <FIG>, various other shapes may also be used for the housing window. In addition, the housing window may be incorporated onto non-flat surfaces of the housing. In other words, the housing window may not be flat, but may be substantially flat and/or curved.

In some instances the entire sensor housing <NUM>, or a large portion of the sensor housing <NUM>, may be penetrable by the signals transmitted and received by the internal sensor components, thereby allowing a large portion or the entire sensor housing <NUM> to function as a housing window. As such, although the housing window <NUM> is shown as being only a portion of the sidewall <NUM>, in some instances the entire sidewall <NUM> may be constructed as a housing window. Further, multiple housing windows may be positioned on the sensor housing <NUM>. The housing window <NUM> may be composed of the same, or different, material as the sensor housing <NUM>.

The sensor <NUM> and/or sensor housing <NUM> may be attached to a motor via a sensor shaft. For instance, as further shown in <FIG>, the sensor shaft <NUM> may include a first end <NUM> and a second end <NUM>. The first end of the of a sensor shaft <NUM> may be attached to a sensor motor <NUM> and the second end of the sensor shaft <NUM> may be connected to the sensor <NUM> and/or sensor housing <NUM>, such as at the base <NUM> of the sensor cover. In this regard, the first end of the sensor shaft <NUM> may be attached to the motor <NUM> via a belt, gear, chain, friction roller, etc. The motor <NUM> may rotate the sensor shaft <NUM> in the first direction <NUM> causing the entire sensor <NUM> and/or sensor housing <NUM> to also rotate in the first direction <NUM>. In some embodiments the sensor shaft <NUM> may only rotate the sensor housing <NUM>, and not the internal components <NUM> of the sensor. The sensor <NUM>, sensor housing <NUM>, and/or motor <NUM> may each be located internally or externally from a vehicle.

A spoiler edge may be incorporated into or attached to the sensor housing. In this regard, the spoiler edge may be positioned adjacent to the housing window and configured such that the spoiler edge extends away from the housing window and/or sensor housing. For example, a spoiler edge <NUM> may be positioned adjacent to the housing window <NUM> of sensor <NUM> (which may be compared to sensor <NUM>), as shown in <FIG>. In this regard, the spoiler edge <NUM> may be positioned such that the spoiler edge is at a leading position relative to the housing window <NUM> during rotation in a first direction <NUM>. The spoiler edge <NUM> may be extended from the housing window <NUM> perpendicular to the axis of rotation <NUM> of the sensor <NUM>. The spoiler edge <NUM> may be extended, or otherwise elevated, from the housing window <NUM> by a percentage of the diameter of the sensor housing <NUM>. For instance, the height of the spoiler edge <NUM> may be between <NUM>% - <NUM>% of the sensor housing diameter.

The spoiler edge <NUM> may be the same or a different material than the sensor housing <NUM> and/or housing window <NUM>. The spoiler edge <NUM> may be glued, welded, or otherwise attached to the sensor housing <NUM>. In some instances, the spoiler edge <NUM> may be an integrated part of the sensor housing <NUM> and/or housing window <NUM>.

Particles, such as dust, dirt, water, snow, ice, etc., may be traveling (i.e., in the air or environment) on trajectories towards the sensor housing, particularly in instances where the sensor is in motion. For example, <FIG> illustrates a top down view of sensor <NUM> mounted or otherwise attached to a vehicle, such as vehicle <NUM> (not shown). As the vehicle <NUM> moves in a first direction illustrated by arrow <NUM>, the sensor <NUM> may also move in the first direction. The movement of the sensor <NUM> in the direction of arrow <NUM> may result in particles in the vicinity of the sensor <NUM>, such as particles <NUM>, <NUM> and <NUM> having trajectories 402a, 402b, and 402c respectively, directed towards the sensor <NUM> in a second direction illustrated by the arrows on the trajectories. Although <FIG> illustrates the second direction as being opposite the first direction, the second direction may be any direction relative to the first direction such that the particles are directed towards the sensor housing and/or housing window <NUM>.

In the event the sensor housing <NUM> is not rotating relative to the vehicle, such as shown in <FIG>, the particles <NUM>-<NUM> may continue along their respective trajectories 402a-402c towards the sensor housing <NUM> with little, if any interference from the sensor housing <NUM> and/or spoiler edge <NUM>. For instance, the particles <NUM>-<NUM> may continue along their respective trajectories 402a-402c and contact the housing window and sensor housing at locations <NUM>, <NUM>, and <NUM>, respectively. As such, the particles <NUM>, <NUM>, and <NUM> may potentially interfere with the operation of the sensor <NUM>.

The spoiler edge may after the path of particles as they approach the sensor housing. In this regard, the rotation of the spoiler edge <NUM> and sensor housing <NUM> in a direction <NUM> generates an airflow <NUM> that travels parallel, or nearly parallel, to the sensor housing <NUM> and housing window <NUM> and away from the spoiler edge <NUM>, as shown in <FIG>. Upon the particles <NUM> and <NUM> coming into this airflow <NUM>, the particles are subjected to the airflow <NUM> and their respective trajectories 402a and 402b may be altered, as further shown in <FIG>. Particle <NUM>, traveling along trajectory 402c may be physically blocked by the spoiler edge <NUM> at impact point <NUM>. As such, some, or all of the particles may be directed away from the sensor housing <NUM> and/or housing window <NUM> and/or block by the spoiler edge.

During rotation of the sensor housing, the spoiler edge may cast a "shadow region" having a certain length on the sensor housing. In this shadow region, particles may not be able to contact the sensor housing. For instance, as shown in <FIG>, the spoiler edge <NUM> and sensor housing <NUM> may rotate in direction <NUM>. The rotation of the spoiler edge <NUM> may cause the spoiler edge <NUM> to cast a shadow region <NUM> on the sensor housing <NUM> and housing window <NUM>. In other words, the shadow region <NUM> may be formed by the rotation of the spoiler edge <NUM> blocking all particles which have a trajectory which would result in the particles contacting a portion of the sensor housing <NUM> and/or housing window <NUM> within the shadow region <NUM>.

The size of the shadow region may be adjusted by altering various characteristics such as the spoiler's height, the rotation speed of the spoiler edge, and/or the speed at which the particles approach the sensor housing. Each of these characteristics may be dependent on the speed the vehicle or other object on which the sensor is mounted. In this regard, the faster the particles (e.g. droplets of water) approach the sensor housing, the smaller the shadow region. Of course, the shadow region may be increased by increasing the speed of the rotation of the spoiler edge and/or the height of the spoiler edge (i.e., distance away from the housing window and perpendicular to the axis of rotation). For example, <FIG> shows the shadow region <NUM> formed by a spoiler edge <NUM> having an increased height relative to the spoiler edge <NUM> of <FIG>. As such, the shadow region <NUM> cast by spoiler edge <NUM> covers a greater area of the sensor housing <NUM> and housing window <NUM> than spoiler edge <NUM>.

Particles which are not blocked from contacting the sensor housing may have their path altered by the airflow generated by the rotation of the sensor housing and/or spoiler edge. The amount of alternation to the particles' paths may be based upon the size of the respective particle. In this regard, smaller, lighter particles may be subjected to greater path alteration by the airflow generated by the spoiler edge, such as airflow <NUM>, as compared to the path alteration of larger, heavier particles. As such, larger particles may contact the sensor housing closer to the spoiler edge than smaller particles. For example, the trajectories of larger particles may be offset only slightly by the airflow <NUM>, thereby allowing the larger particles to contact the sensor housing <NUM> and/or housing window <NUM> in region <NUM>, which is close to the shadow region <NUM> generated by the spoiler edge <NUM>, as shown in <FIG>. The trajectories of smaller particles may be more offset by the airflow <NUM>, such that the smaller particles contact the sensor housing <NUM> and/or housing window <NUM> in region <NUM>, which is outside of the both the shadow region <NUM> and region <NUM>. The trajectories of even smaller particles may be offset such that these smaller particles contact the sensor housing <NUM> and/or housing window <NUM> in region <NUM>, which is outside of the both the shadow region <NUM>, region <NUM>, and region <NUM>. The trajectories of the smallest particles may be offset such that they do not contact the sensor housing <NUM> or housing window <NUM>.

Particles which do contact the sensor housing may be ejected from the sensor housing and/or moved away from the housing window via the centripetal force generated by rotating the sensor housing. In this regard, a particle's adhesion force may be approximately proportional to the particle's contact area with the sensor housing. The contact area may be proportional to the square of the particle's diameter. Centripetal force, however, may be proportional to the particle's mass, which may grow as a cubic function of the particle's diameter. Thus, the centripetal force may grow faster with growing particle diameter than the adhesion force of the particle. Accordingly, larger particles which may contact the sensor housing or housing window are subjected to a centripetal force greater than their adhesion force and can be ejected from the sensor housing and/or moved away from the housing window by rotating the sensor housing. In some instances, a hydrophobic coating may also be applied to the sensor housing in order to reduce the particles adhesion force and thereby reduce the amount of centripetal force to remove and/or move the particle.

Turning to the example of <FIG>, a particle <NUM> may contact the housing window <NUM> of sensor <NUM>. Rotation of the sensor housing <NUM> in direction <NUM> may generate a centripetal force on the particle <NUM>. The centripetal force may cause the particle <NUM> to move across the sensor housing <NUM> in a direction illustrated by arrow <NUM>, away from the housing window <NUM>, as illustrated in <FIG>. Continued centripetal force may cause the particle <NUM> to be ejected from the sensor housing <NUM> in a particular direction, as illustrated by arrow <NUM>. Accordingly, the particle <NUM> is eliminated from the sensor housing <NUM> by a centripetal force generated from the rotation of the sensor <NUM>.

Claim 1:
A sensor housing (<NUM>) for preventing particle buildup on a housing window, the sensor housing comprising:
a first surface in which the housing window (<NUM>) is included; and
a spoiler edge (<NUM>), wherein the spoiler edge is positioned adjacent to the housing window and extended away from the first surface perpendicular to an axis of rotation (<NUM>) of the sensor housing and wherein the spoiler edge is configured to generate an airflow (<NUM>) substantially parallel to the housing window and away from the spoiler edge (<NUM>) during rotation of the sensor housing