Ice and snow detection systems and methods

Example ice and snow detection systems and methods are described. In one implementation, a method activates an ice and snow detection system in response to receiving weather data indicating a likelihood of ice or snow on a roadway near a vehicle. The method receives data from multiple vehicle sensors and analyzes the received data to identify ice or snow on the roadway. If ice or snow is identified on the roadway, the method adjusts vehicle operations and reports the ice or snow condition to a shared database.

TECHNICAL FIELD

The present disclosure relates to vehicular systems and, more particularly, to systems and methods that detect the presence of ice or snow on a roadway.

BACKGROUND

Automobiles and other vehicles provide a significant portion of transportation for commercial, government, and private entities. Vehicles, such as autonomous vehicles, drive on roadways that may experience a build-up of ice or snow on the roadway surface. The presence of ice or snow on a roadway presents a potential risk to the vehicle due to a loss of traction with the roadway surface and a resulting loss of vehicle control. Thus, ice or snow on a roadway surface presents a risk of injury to occupants of vehicles driving on roadways with ice or snow. Detection of ice or snow on a roadway can reduce the likelihood of accidents and potential injury to vehicle occupants.

DETAILED DESCRIPTION

At least some embodiments of the disclosure are directed to computer program products comprising such logic (e.g., in the form of software) stored on any computer useable medium. Such software, when executed in one or more data processing devices, causes a device to operate as described herein.

FIG. 1is a block diagram illustrating an embodiment of a vehicle control system100that includes an ice and snow detection system104. An automated driving/assistance system102may be used to automate or control operation of a vehicle or to provide assistance to a human driver. For example, the automated driving/assistance system102may control one or more of braking, steering, seat belt tension, acceleration, lights, alerts, driver notifications, radio, vehicle locks, or any other auxiliary systems of the vehicle. In another example, the automated driving/assistance system102may not be able to provide any control of the driving (e.g., steering, acceleration, or braking), but may provide notifications and alerts to assist a human driver in driving safely. Vehicle control system100includes an ice and snow detection system104that interacts with various components in the vehicle control system to detect and respond to ice or snow on a roadway near the vehicle. In one embodiment, ice and snow detection system104detects ice or snow in the path of the vehicle (e.g., ahead of the vehicle) and adjusts one or more vehicle operations to avoid the ice/snow or allow the vehicle to safely drive across the ice/snow. Although ice and snow detection system104is shown as a separate component inFIG. 1, in alternate embodiments, ice and snow detection system104may be incorporated into automated driving/assistance system102or any other vehicle component.

The vehicle control system100also includes one or more sensor systems/devices for detecting a presence of nearby objects or determining a location of a parent vehicle (e.g., a vehicle that includes the vehicle control system100). For example, the vehicle control system100may include radar systems106, one or more LIDAR systems108, one or more camera systems110, a global positioning system (GPS)112, and/or ultrasound systems114. The one or more camera systems110may include a rear-facing camera mounted to the vehicle (e.g., a rear portion of the vehicle), a front-facing camera, and a side-facing camera. Camera systems110may also include one or more interior cameras that capture images of passengers and other objects inside the vehicle. The vehicle control system100may include a data store116for storing relevant or useful data for navigation and safety, such as map data, driving history, or other data. Additionally, data store116may store information related to ice or snow previously detected by the current vehicle or reported by other vehicles. The vehicle control system100may also include a transceiver118for wireless communication with a mobile or wireless network, other vehicles, infrastructure, or any other communication system.

The vehicle control system100may include vehicle control actuators120to control various aspects of the driving of the vehicle such as electric motors, switches or other actuators, to control braking, acceleration, steering, seat belt tension, door locks, or the like. The vehicle control system100may also include one or more displays122, speakers124, or other devices so that notifications to a human driver or passenger may be provided. A display122may include a heads-up display, dashboard display or indicator, a display screen, or any other visual indicator, which may be seen by a driver or passenger of a vehicle. The speakers124may include one or more speakers of a sound system of a vehicle or may include a speaker dedicated to driver or passenger notification.

It will be appreciated that the embodiment ofFIG. 1is given by way of example only. Other embodiments may include fewer or additional components without departing from the scope of the disclosure. Additionally, illustrated components may be combined or included within other components without limitation.

In one embodiment, the automated driving/assistance system102is configured to control driving or navigation of a parent vehicle. For example, the automated driving/assistance system102may control the vehicle control actuators120to drive a path on a road, parking lot, driveway or other location. For example, the automated driving/assistance system102may determine a path based on information or perception data provided by any of the components106-118. A path may also be determined based on a route that maneuvers the vehicle around an approaching patch of ice or snow on the roadway. The sensor systems/devices106-110and114may be used to obtain real-time sensor data so that the automated driving/assistance system102can assist a driver or drive a vehicle in real-time.

FIG. 2is a block diagram illustrating an embodiment of ice and snow detection system104. As shown inFIG. 2, ice and snow detection system104includes a communication manager202, a processor204, and a memory206. Communication manager202allows ice and snow detection system104to communicate with other systems, such as automated driving/assistance system102. Processor204executes various instructions to implement the functionality provided by ice and snow detection system104as discussed herein. Memory206stores these instructions as well as other data used by processor204and other modules and components contained in ice and snow detection system104.

Additionally, ice and snow detection system104includes an image processing module208that receives image data from one or more camera systems110and identifies, for example, ice or snow on a roadway near the vehicle. In some embodiments, image processing module208includes an ice and snow detection algorithm that identifies patches of ice or snow in the images of the roadway ahead of the vehicle. A LIDAR processing module210receives LIDAR data from one or more LIDAR systems108and identifies, for example, ice or snow on the roadway ahead of the vehicle. Similarly, a radar processing module212receives radar data from one or more radar systems106to identify, for example, ice or snow in the planned path of the vehicle.

Ice and snow detection system104also includes a map and drive history module214that receives road map information from one or more data sources, and receives vehicle drive history data from data store116. In some embodiments, map and drive history module214uses the road map and drive history data to detect a difference in road surface height (or elevation), indicating the possibility of a build-up of ice or snow on the road surface. A data analysis module216performs various operations on data received from any number of sensors and/or data sources to detect the presence of ice or snow on a roadway surface.

Additionally, ice and snow detection system104includes a weather monitor218that monitors weather conditions near the vehicle and receives weather-related data from any number of data sources. A vehicle operation manager220adjusts various vehicle operations based on detection of ice or snow on the roadway, as discussed here. A vehicle traction manager222monitors a vehicle's traction between the vehicle's tires and the road surface to detect any slippage or skidding of the tires on the road surface. This slippage or skidding may indicate the presence of ice or snow on the surface of the roadway.

FIG. 3illustrates an embodiment of a method300for detecting ice or snow on a roadway. Initially, a vehicle receives302current weather data from a weather service provider or other weather data source. In some embodiments, ice and snow detection system104is activated when weather conditions near the vehicle are likely to produce ice or snow on the road surface. For example, if the weather near the vehicle is sunny with temperatures significantly above freezing, it may not be necessary to operate ice and snow detection system104. However, if the temperature drops closer to freezing and precipitation is detected (or predicted by the weather data), ice and snow detection system104may be activated to monitor the roadway for ice or snow.

Method300continues as ice and snow detection system104receives304road condition data and drive history information from one or more sources. The road condition data may be received from any number of data sources, such as travel data sources, weather data sources, other organizations, other vehicles, other individuals, and the like. Example road condition data may indicate a significant likelihood of road icing or reports of actual ice or snow in the roadway. The drive history information includes, for example, road information and related data obtained by the vehicle during previous driving activities.

Ice and snow detection system104fuses the image data, LIDAR data, and radar data, then analyzes306the fused data to identify ice or snow on the roadway. For example, the fused data may provide a more complete coverage of the approaching environment. One type of sensor may “fill in” the gaps of another sensor type, thereby compensating for the weakness of a particular sensor. By combining data from multiple sensors, the combined confidence level may be greater because the confidence level is based on multiple sets of data from different types of sensors. In some embodiments, the image data, LIDAR data, and radar data is primarily associated with an area ahead of the vehicle (e.g., the area being approached by the vehicle). In other embodiments, the image data, LIDAR data, and radar data is associated with areas to the side of the vehicle and/or areas behind the vehicle. If snow or ice is not identified308, the method300continues receiving and analyzing data to detect possible ice or snow at a future time.

In particular embodiments, ice or snow is detected on the roadway by determining a current height (e.g., elevation) of the roadway surface and comparing that height to a previously recorded height of the roadway surface or height data from roadway map data. The described systems and methods determine that ice or snow is present on the roadway if the current height of the roadway surface is greater than the previously recorded height of the roadway surface. The increased roadway surface height is attributed to a build-up of ice or snow on the roadway, causing an appearance that the roadway surface is higher than previously recorded. If multiple vehicle sensors detect an increased roadway surface height, a greater confidence level is achieved as compared to a single sensor detecting an increased roadway surface height. In particular embodiments, one or more LIDAR systems108determine the current height of the roadway surface.

In other embodiments, ice or snow is detected on the roadway by determining a current reflectivity of the roadway surface and comparing the current reflectivity of the roadway surface to a previously recorded reflectivity of the roadway surface. The described systems and methods determine that ice or snow is present on the roadway if the current reflectivity of the roadway surface is greater than the previously recorded reflectivity of the roadway surface. The increased roadway surface reflectivity is attributed to a build-up of ice or snow on the roadway, causing greater reflectivity than a non-icy roadway surface. In some embodiments, the reflectivity includes one or more of: visual reflectivity, LIDAR reflectivity, and radar reflectivity. In particular embodiments, one or more of radar systems106, LIDAR systems108, and camera systems110are used to determine whether the roadway surface has characteristics of the appearance of ice or snow.

In particular embodiments, ice or snow is detected on the roadway by determining a current road geometry of the roadway surface and comparing the comparing the current road geometry of the roadway surface to a previously recorded road geometry of the roadway surface. The road geometry includes a roughness (or other irregularity), smoothness or other road characteristic. The described systems and methods determine that ice or snow is present on the roadway if the current road geometry of the roadway surface is different than the previously recorded road geometry of the roadway surface. The changed road geometry may be caused by a build-up of ice or snow on the roadway, causing a rougher road than a non-icy roadway surface. In some embodiments, the roughness of the roadway surface is determined using the locations of points in a LIDAR point cloud on the surface of the roadway. In other embodiments, images captured by camera systems110detect visual roughness on the roadway surface.

If method300detects ice or snow on the roadway, vehicle operations are adjusted310based on the ice or snow. As discussed in greater detail with respect toFIG. 4, vehicle operations are adjusted to maneuver around the ice/snow on the roadway (if possible) or improve the control of the vehicle as it drives across the ice or snow. The ice or snow condition is reported312to a shared database (or other data storage mechanism) along with a geographic location associated with the ice and snow. This ice or snow condition report represents road condition data that may be used by other vehicles traveling on the same road or traveling on other roads in the same area which may experience similar ice or snow conditions. In some embodiments, the ice/snow condition and the geographic location is also recorded in the vehicle's drive history. In addition to adjusting vehicle operations310, some embodiments of method300also attempt to maneuver314the vehicle around the ice or snow, thereby avoiding the potentially slippery area of the roadway.

FIG. 4illustrates an embodiment of a method400for adjusting vehicle operations in response to detecting ice or snow on a roadway. Initially, ice and snow detection system104detects402ice or snow on the roadway as discussed, for example, with respect toFIG. 3. In some embodiments, method400reduces404the speed of the vehicle such that the vehicle crosses the ice or snow at a slower speed at which the driver or automated driving/assistance system102can better maintain control of the vehicle. In particular situations, an active clutch is engaged406for a 4-wheel-drive system. Thus, rather than waiting until the car begins to slip or skid on the ice/snow, the active clutch is engaged such that the 4-wheel-drive system is actively operating to maintain traction for the vehicle and improve control of the vehicle as it drives across the ice or snow.

In some embodiments, ice and snow detection system104avoids408sudden vehicle speed changes (e.g., sudden acceleration or sudden deceleration) that may cause the vehicle to lose traction with the roadway and potentially lose control of the vehicle. Additionally, ice and snow detection system104avoids410sudden turning of the front wheels that may cause the vehicle to lose traction with the roadway. If steering is required, ice and snow detection system104attempts to make small steering changes while maintaining traction between the vehicle's tires and the roadway. Method400continues monitoring412the vehicle traction with the road surface and makes any necessary adjustments to maintain traction between the vehicle's tires and the roadway.

In some embodiments, the adjustments discussed with respect toFIG. 4are implemented by sending appropriate instructions to one or more vehicle control actuators120. For example, instructions may be sent to vehicle control actuators120to control braking, acceleration, and steering.

FIG. 5illustrates an embodiment500of vehicle approaching ice or snow on a roadway. A vehicle502is traveling along a roadway506and is approaching a patch of ice/snow504on the roadway. One or more vehicle sensors (e.g., radar systems106, LIDAR systems108, and camera systems110) may detect ice/snow504as indicated by broken lines508representing the detection area identified by the sensors. In some embodiments, a vehicle may attempt to maneuver around approaching ice or snow on the roadway. However, in the example ofFIG. 5, vehicle502is not able to maneuver around ice/snow504without driving off the roadway or driving into oncoming traffic. In this situation, the systems and methods described herein adjust the operation of vehicle502to increase the likelihood that vehicle502maintains control as it drives across ice/snow504.

While various embodiments of the present disclosure are described herein, it should be understood that they are presented by way of example only, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the disclosure. Thus, the breadth and scope of the present disclosure should not be limited by any of the described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. The description herein is presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Many modifications and variations are possible in light of the disclosed teaching. Further, it should be noted that any or all of the alternate implementations discussed herein may be used in any combination desired to form additional hybrid implementations of the disclosure.