Apparatus and method for extended forward collision warning

Abstract

The present disclosure relates to an apparatus and method for extended forward collision warning. A method and system generate a collision warning to the driver of a host vehicle. The system includes onboard sensors of the host vehicle to detect the presence of a preceding vehicle; wireless communication circuitry to establish wireless communication with a remote vehicle; and processing circuitry to detect the presence of a slow-moving remote vehicle in front of the host vehicle, track the immediately preceding vehicle in front of the host vehicle, and confirm that the slow-moving remote vehicle is affecting the speed of traffic in the host vehicle's lane by detecting that the immediately preceding vehicle is decelerating. When the remote vehicle is determined to be slow, an information message indicating the presence of the slow-moving remote vehicle is displayed, and when the remote vehicle is slow and the preceding vehicle is decelerating, a collision warning is output as an audible and visual message.

Description

Technical Field

[0001] The present disclosure relates generally to the field of vehicle communication systems and mechanisms for providing reliable collision warnings to vehicles. Background Art

[0002] The "background" description provided herein is for the purpose of generally presenting the context of the present disclosure. To the extent described in this background section, the work of the presently designated inventors and aspects of the specification that may not qualify as prior art at the time of filing are neither explicitly nor implicitly admitted to be prior art to the present invention.

[0003] Vehicles include brake lights that illuminate when the driver applies the vehicle's brakes. The brake lights serve as a mechanism to warn other drivers behind the vehicle when the vehicle is slowing down so that other drivers can also slow down to avoid a collision with the vehicle.

[0004] However, in heavy traffic conditions, there may be other remote vehicles ahead of the vehicle being followed. Heavy traffic conditions may include a stopped condition caused by operational changes in the remote vehicle that the driver cannot clearly see, and the driver may not be aware of the operational changes. In such situations, the driver may rely on the brake lights of the vehicle being followed as the sole indicator of traffic conditions. Furthermore, in some cases, brake lights are insufficient to warn other drivers that the vehicle is decelerating. For example, the driver of a following vehicle may not be able to see the brake lights of the vehicle ahead of the vehicle being followed. If the vehicle is negotiating a sharp turn, the driver of the following vehicle may not be able to see the brake lights of the vehicle ahead and may therefore not be warned in time. Furthermore, weather conditions such as fog, heavy rain, and / or heavy snow may limit the transmission range of brake lights. Furthermore, brake lights may malfunction, and / or the driver of the following vehicle may simply be unaware of the brake lights of the vehicle ahead. Such situations can prove potentially harmful to the vehicle's driver.

[0005] Throughout this disclosure, reference is made to the terms "host vehicle," "leading vehicle," and "remote vehicle." In various aspects of this disclosure, a leading vehicle is intended to refer to a vehicle traveling immediately ahead of the host vehicle on a given road, while a remote vehicle is intended to refer to a vehicle traveling further ahead of the host vehicle (and the leading vehicle) on the road. Furthermore, throughout this disclosure, the host vehicle is designated as an "HV," the leading vehicle is designated as a "PV," and the remote vehicle is designated as an "RV."

[0006] Adaptive cruise control mechanisms are used to maintain a desired cruising speed for a vehicle (HV) in order to maintain a safe distance from a preceding vehicle (PV). However, in heavy traffic, the preceding vehicle (PV) may experience significant speed changes, necessitating similar speed changes within the vehicle (HV). Emergency electronic brake lights are another mechanism used to warn the driver of a vehicle (HV) of an impending collision. However, these mechanisms typically only detect situations where the preceding vehicle brakes suddenly and therefore do not react to a remote vehicle (RV) that is already significantly slower. Consequently, in some cases, these collision avoidance mechanisms can provide an uncomfortable or dangerous experience for the vehicle driver.

[0007] Therefore, there is a need for a technology that can warn a vehicle driver of an impending collision in a time-efficient manner, wherein the vehicle driver can comfortably slow down to avoid the collision. Summary of the Invention

[0008] In an exemplary embodiment, a method of generating a collision warning to a driver of a host vehicle includes detecting the presence of a slow remote vehicle in front of the host vehicle; tracking the speed of an immediately preceding vehicle in front of the host vehicle; confirming that the slow remote vehicle is affecting the speed of traffic in the lane of the host vehicle by detecting that the immediately preceding vehicle (e.g., the immediately preceding vehicle) is decelerating; displaying an information message indicating the presence of the slow remote vehicle when the slow remote vehicle is detected and the immediately preceding vehicle is being tracked; and outputting a collision warning as an audible and visual message when the slow remote vehicle is detected and the immediately preceding vehicle is decelerating.

[0009] In an exemplary embodiment, a system for generating a collision warning to a driver of a host vehicle includes onboard sensors of the host vehicle for detecting the presence of a leading vehicle; wireless communication circuitry for establishing wireless communication with a remote vehicle; processing circuitry for detecting the presence of a slow remote vehicle in front of the host vehicle; tracking the immediately preceding vehicle in front of the host vehicle; confirming that the slow remote vehicle is affecting the speed of traffic in the lane of the host vehicle by detecting that the immediately preceding vehicle is decelerating; displaying an information message indicating the presence of the slow remote vehicle when the slow remote vehicle is detected and the immediately preceding vehicle is being tracked; and outputting a collision warning as an audible and visual message when the slow remote vehicle is detected and the immediately preceding vehicle is decelerating.

[0010] The foregoing general description and the following detailed description of the illustrative embodiments are merely exemplary aspects of the teachings of the present disclosure and are not restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A more complete appreciation of the present disclosure and its many attendant advantages will be readily obtained as the present disclosure and its many attendant advantages become better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which:

[0012] Figure 1 An expanded forward collision warning system according to an exemplary aspect of the present disclosure is shown;

[0013] Figure 2 is a hardware block diagram of a control system included in a vehicle according to an exemplary aspect of the present disclosure;

[0014] Figure 3 is a flow chart of steps performed by an extended forward collision warning system according to an exemplary aspect of the present disclosure;

[0015] Figure 4 is a flow chart of steps performed by a host vehicle to determine the geometry of a lane of a road in which the host vehicle is traveling according to an exemplary aspect of the present disclosure;

[0016] Figure 5 shows a schematic diagram depicting lane estimation based on path histories of two remote vehicles according to an exemplary aspect of the present disclosure;

[0017] Figure 6 is a flow chart of steps performed by a host vehicle to determine behavior of a leading vehicle according to an exemplary aspect of the present disclosure;

[0018] Figure 7 is a flow chart of steps performed by a host vehicle to determine slow or hard braking of a remote vehicle according to an exemplary aspect of the present disclosure;

[0019] Figure 8 is a flow chart of steps of decision logic performed by a host vehicle related to the display of a warning message according to an exemplary aspect of the present disclosure; and

[0020] Figure 9 is a block diagram of a computing device according to an exemplary aspect of the present disclosure. DETAILED DESCRIPTION

[0021] In the drawings, like reference numerals designate identical or corresponding parts throughout the several views. Furthermore, as used herein, the words "a," "an," and the like generally have the meaning of "one or more," unless otherwise indicated. The drawings are generally drawn to scale or depict schematic structures or flow diagrams, unless otherwise indicated.

[0022] The embodiments are described primarily in terms of specific processes and systems provided in specific implementations. However, the processes and systems will operate effectively in other implementations. Phrases such as "an embodiment," "one embodiment," and "another embodiment" may refer to the same or different embodiments. The embodiments will be described with respect to methods and compositions having certain components. However, these methods and compositions may include more or fewer components than those shown, and the arrangement and types of components may be changed without departing from the scope of this disclosure.

[0023] The exemplary embodiments are described in the context of methods having certain steps. However, these methods and compositions can be effectively operated with additional steps and with steps in a different order than is consistent with the exemplary embodiments. Therefore, the present disclosure is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features described herein, and is limited only by the claims.

[0024] Aspects of the present disclosure are directed to a configuration in which communication is established between a remote vehicle (RV) and a host vehicle (HV) while the state of a preceding vehicle (PV) is determined based on sensors (e.g., cameras) of a subject vehicle (HV).

[0025] Now go to Figure 1 , which shows an extended forward collision warning (E-FCW) system 100 according to one embodiment. Figure 1 The illustrated E-FCW system 100 includes a host vehicle (HV) 101 traveling behind a vehicle 103. Vehicle 103 is a preceding vehicle (PV). Vehicles 105, 107, 109, and 111 are remote vehicles (RVs) traveling in front of the preceding vehicle (PV) 103. For purposes of illustration, all of the remote vehicles (RVs) 105, 107, 109, and 111 are depicted as traveling in the same lane (i.e., a straight line) as the host vehicle (HV) 101.

[0026] According to one embodiment, the host vehicle (HV) 101 includes an electronic control unit (ECU) (also referred to herein as an embedded computer unit and later referred to as an embedded computer unit) that controls one or more electrical systems or subsystems in the vehicle. Figure 2 The ECU is configured to receive data from onboard sensors and also perform the required calculations to warn the driver of the host vehicle (HV) 101 of an impending collision. By one embodiment, the host vehicle (HV) 101 utilizes both line-of-sight sensors and non-line-of-sight sensors to provide timely warnings to the driver of the host vehicle (HV) 101.

[0027] The host vehicle (HV) 101 includes a radar sensor that uses radio waves 108 to detect objects and determine their position and velocity. Figure 1 As shown, radio waves 108 are used to detect and track the movement of a preceding vehicle (PV) 103. The radar included in the host vehicle (HV) 101 can be a long-range radar with a narrow field of view, a medium-range radar, or a short-range radar with a wider field of view. Additionally, the host vehicle (HV) 101 can be equipped with a camera to track the preceding vehicle (PV) 103. The camera can be integrated into a monocular or stereo configuration. A monocular camera has a field of view of 50 to 60 degrees and a range of 100-200 meters. On the other hand, a stereo camera performs the same task as a monocular camera but provides greater reliability. Furthermore, the host vehicle (HV) 101 can also include a light detection and ranging (LIDAR) sensor, which can be used to track the preceding vehicle (PV) 103. Therefore, in this embodiment, the host vehicle (HV) 101 tracks the immediately preceding vehicle (PV) 103 by using at least one of a radar sensor, a LIDAR sensor, and a camera.

[0028] The host vehicle (HV) 101 also includes non-line-of-sight sensors, such as dedicated short-range communication sensors (DSRC), cellular sensors, etc., to identify remote vehicles (RVs) traveling in the same lane as the host vehicle (HV) (also referred to herein as the "self" lane, i.e., the lane of the road the host vehicle is traveling in). Figure 1 As shown, a host vehicle (HV) 101 utilizes non-line-of-sight sensors to identify remote vehicles (RVs) 111 and 107 traveling in the ego lane at a speed significantly lower than the host vehicle (HV) 101. The remote vehicles (RVs) 111 and 107 are identified by non-line-of-sight communications, denoted as 104 and 106, respectively.

[0029] According to one embodiment, a host vehicle (HV) 101 identifies a remote vehicle (RV) traveling in its own lane at a slower speed (compared to the host vehicle's current speed) or a remote vehicle (RV) parked in its own lane. Furthermore, utilizing a line-of-sight sensor, the host vehicle (HV) 101 tracks the preceding vehicle 103 and, based on the determination of the remote vehicle's motion, predicts the motion of the preceding vehicle (PV) 103. Thus, based on the aforementioned identification and tracking performed by the host vehicle (HV), the ECU in the host vehicle (HV) 101 warns the driver to either decelerate comfortably or brake immediately to avoid a collision. In some embodiments, the ECU displays a message notifying the driver that the RV is traveling significantly slower than highway speeds on the same road, for example, less than 20 mph. When such a slow RV is detected and the PV appears to be slowing down, the ECU displays an urgent warning and provides an audible warning. The ECU also displays a warning when an RV in an adjacent lane is slow and the PV is slowing down.

[0030] Figure 2 An embodiment includes Figure 1FIG2 is a hardware block diagram of an embedded control system 200 in a host vehicle (HV) 101. The embedded control system 200 includes an electronic subsystem-I 201 and an electronic subsystem-II 203 coupled together via an electronic bus 223. Subsystems 201 and 203 include an embedded control unit (ECU), i.e., a processing circuit that controls one or more electrical systems or subsystems in the vehicle (see later). Figure 9 ).

[0031] ECUs receive data from onboard sensors and perform information processing operations, distributing instructions to various in-vehicle systems. It's important to understand that each ECU can operate independently, running its own firmware. However, ECUs can collaborate with one another to handle complex processing operations.

[0032] Subsystem 201 includes a camera 213 and a line-of-sight sensor radar 215, coupled to an image processor 217 and a radar ECU 219, respectively. Radar 215 uses radio waves to detect vehicles and determine the speed of the detected vehicles. Radar 215 can be a long-range radar with a narrow field of view, a medium-range radar, or a short-range radar with a wider field of view. Camera 213 can be used to track a preceding vehicle (PV). As previously mentioned, the camera can be a monocular or stereo camera. Image processor 217 and radar ECU 219 are coupled to an onboard ECU 221, which can be configured to process the combined information received from camera 213 and radar 215.

[0033] Subsystem 203 includes a GPS antenna 227 coupled to a GPS ECU module 233. The data obtained from the GPS can be used to determine several valuable pieces of information, including how far the vehicle has traveled, how long the vehicle has traveled, the vehicle's current and average speed, and its estimated time to reach its destination. In addition, subsystem 203 also includes non-line-of-sight sensors that can operate in the 5.9 GHz spectrum, such as dedicated short-range communication sensors (DSRC). For example, Figure 2 As shown, subsystem 203 includes a DSRC antenna 229 coupled to a DSRC radio 231 .

[0034] Subsystems 201 and 203 are coupled together via a serial bus 223. Serial bus 223 may be a controller area network (CAN) type serial bus, which allows ECUs to communicate with each other within the vehicle. Additionally, CAN may be low-speed CAN (ISO 11519) providing data rates up to 125 Kbps, or alternatively, high-speed CAN (ISO 11898) achieving data rates up to 1 Mbps. It should be understood that serial bus 223 may also be a local interconnect network (LIN) or a FlexRay type serial bus providing two 10 Mbps data channels.

[0035] By one embodiment, subsystems 201 and 203 can be coupled to a vehicle bus 235 that provides an Ethernet connection to various modules included in the vehicle system, such as a 4G radio 207. Additionally, subsystems 201 and 203 can communicate with a driver assistance system (DAS) map via serial bus 223 that provides information such as road curvature, the number of lanes on the road, and the like. Figure 2 The illustrated system 200 includes a storage device (memory) 209 in which information processed by the ECU can be stored. For example, as described later, the host vehicle (HV) can maintain a queue of remote vehicles (RVs) that the host vehicle (HV) is currently tracking. Such tracking information can be stored in the memory 209. In addition, the subsystems 201 and 203 can be coupled to a center console unit 211 via a digital I / O interface. The center console 211 includes a display panel and a speaker, which can be used to provide audiovisual warning messages to the vehicle driver. Therefore, as described below, the host vehicle (HV) incorporates both line-of-sight sensors and non-line-of-sight sensors to issue collision warnings to the vehicle driver.

[0036] Figure 3 A flowchart 300 is depicted showing steps that may be performed by the E-FCW system. Although the steps in the flowchart are shown in a certain order, the order of the steps is not limited to this ordering. Additionally, some steps may be performed in parallel. For example, PV behavior may be performed in a reverse order or in parallel with HV road geometry estimation. Processing 300 begins at step S301, where the E-FCW system determines the type of road on which the host vehicle is traveling. According to one embodiment, the host vehicle (HV) utilizes a line of sight sensor to determine the type of road. Specifically, the host vehicle (HV) utilizes a line of sight sensor to determine whether the road on which the host vehicle (HV) is currently traveling is a "divided highway."

[0037] In one embodiment, the E-FCW system classifies a road as a divided-lane highway only if the following two conditions are met: (a) the current speed at which the vehicle is traveling (denoted as v(t)) is greater than a predetermined speed threshold (V), and (b) the vehicle speed within a certain time window (T) is greater than the predetermined speed threshold. Specifically, for values of τ < T, the vehicle speed (v(t - τ)) is greater than V. In one embodiment, the E-FCW system uses values of V = 45 miles per hour (mph) and T = 30 seconds (sec) to determine whether the road on which the vehicle is traveling is a divided-lane highway.

[0038] In contrast, if within a predetermined distance (D) traversed by the host vehicle (HV) (also referred to herein as the ego vehicle), one of the following two conditions is met, the E-FCW system classifies the road type as not a divided-lane highway: (a) oncoming traffic with a longitudinal relative speed of at least -5 mph (with respect to the ego vehicle) is detected by the ego vehicle, and (b) traffic with a lateral speed of at least 6 mph is detected by the ego vehicle.

[0039] Then, process 300 proceeds to step S303, where the E-FCW system performs an estimation of the geometry of the lane of the road on which the host vehicle (HV) is traveling. According to one embodiment, the E-FCW system also performs remote vehicle (RV) lane classification. Specifically, the host vehicle (HV) determines whether the remote vehicle (RV) is traveling in the same lane as the host vehicle (HV), or whether the remote vehicle (RV) is traversing in a lane different from the host vehicle's lane. Details regarding the main lane geometry estimation and remote vehicle (RV) lane classification are described later in Figure 4 and Figure 5 description.

[0040] Go to Figure 4 depicts a flowchart that shows the steps performed by the host vehicle to estimate the geometry of the road-lane on which the host vehicle is traveling. According to one embodiment, the host vehicle uses a priority mechanism to estimate the geometry of the lane. Specifically, the host vehicle determines, in decreasing order of priority, whether the tracking history of the leading vehicle is available, whether the tracking history of the remote vehicle (and the predicted path of the host vehicle) is available from two remote vehicles, or whether the host vehicle should estimate the lane geometry based only on the predicted path of the host vehicle. As Figure 4 shown, the process of estimating the geometry of the lane begins at step S401, where a query is made to determine whether sufficient tracking history of the leading vehicle (PV) exists. Note that the host vehicle receives data corresponding to the tracking history of the leading vehicle (PV), e.g., information in the (ASN) 1.0 data packet sent by the leading vehicle.

[0041] If the response to the query in step S401 is affirmative (yes), processing proceeds to step S403. In step S403, the host vehicle (HV) estimates the geometry of the lane based on the tracking history information of the preceding vehicle. According to one embodiment, the host vehicle (HV) implements batch processing techniques, such as least squares fitting and / or Kalman filter-based techniques, to estimate the geometry of the lane. Under the assumption that the vehicle does not deviate too far from the center of the lane, the lane geometry estimation based on the vehicle path can be performed as a problem of fitting a cubic polynomial to the path history points of the preceding vehicle. Other methods of estimating lane geometry may include Kalman filtering / sensor fusion using lane marking recognition as described in U.S. Patent No. 6,292,752, and more complex road models (such as the double clothoid method) described in U.S. Patent No. 6,751,547B2. After the estimation of the road geometry (based on the track history information of the preceding vehicle) is performed in step S403, the processing in 400 terminates.

[0042] However, if the response to the query in step S401 is negative (No), the process proceeds to step S405. In step S405, a query is made to determine whether the path history of the two remote vehicles is available. If the response to the query in step S405 is positive (Yes), the process proceeds to step S407. However, if the response to the query is negative (No), the process moves to step S409.

[0043] In step S407, the host vehicle estimates the geometry of the lane based on the tracking history of the two remote vehicles. Figure 5 The details of this estimation are described below. It should be understood that while the host vehicle performs an estimation of the road geometry based on the tracking histories of the two remote vehicles (S407), the host vehicle also includes the host vehicle's predicted path in its successful estimation of the road lane geometry. Specifically, as shown in step S411, a query is performed to determine whether the paths obtained based on the path histories of the two remote vehicles match the host vehicle's predicted path.

[0044] If the response to the query in step S411 is affirmative (yes), the process terminates. However, if the response to the query (S411) is negative (no), the process proceeds to step S409 to perform an estimation of the geometry of the lane based solely on the predicted path of the host vehicle.

[0045] In step S409, the host vehicle performs lane geometry estimation based solely on the host vehicle's predicted path. For example, according to one embodiment, the host vehicle predicts its future path based on the host vehicle's current steering angle and / or the rate of change of the steering angle. Thus, based on the host vehicle's predicted path, the host vehicle estimates the geometry of the lane it is traveling in. After the road geometry estimation is completed in step S409, as shown in FIG. Figure 4 The process 400 is shown to terminate.

[0046] In addition, according to one embodiment, in the above-mentioned technology for estimating the geometric shape of the road lane, the host vehicle can utilize the information from the DAS map ( Figure 2 The geometry of the lane can be estimated using the information available from 205) and the lane marking recognition information. According to one embodiment, a range sensor, such as a camera with a telephoto lens, can be used to estimate the geometry of the lane.

[0047] [Driveway Geometry – 2 RVs]

[0048] Go to Figure 5 , shows a schematic diagram depicting lane geometry estimation based on the path history of two remote vehicles. Specifically, reference is made here to Figure 5 describe Figure 4 Lane geometry estimation in step S407.

[0049] Figure 5 A host vehicle 510 (also referred to herein as the ego vehicle and denoted as EV) is depicted detecting two remote vehicles 520 and 530, denoted as RV1 and RV2, respectively. According to one embodiment, the host vehicle 510 determines the two remote vehicles 520 and 530 as the remote vehicles closest to the slowest-moving remote vehicle. Note, however, that if only two remote vehicles were detected, both detected vehicles would be used to estimate the geometry of the lane in which the host vehicle is traveling.

[0050] The host vehicle 510 processes and generates path histories 520a and 530a for the remote vehicles 520 and 530, respectively. Specifically, the remote vehicles 520 and 530 transmit data packets that are processed in the host vehicle's ECU. Consequently, the host vehicle 510 processes the data packets and also generates path histories for the remote vehicles 520 and 530, respectively.

[0051] The host vehicle 510 also predicts its future path based on the host vehicle's current steering angle. In doing so, the host vehicle generates its predicted path, which is Figure 5After generating predicted path 510a, the host vehicle processes path histories 520a and 530a of remote vehicles 520 and 530, respectively, to ensure that at least one path history of the remote vehicle is no further than half a lane width from the predicted path of the host vehicle over a certain predetermined length 540.

[0052] Specifically, the host vehicle performs processing to ensure that the host vehicle is within the distance v ev *T evpp At least one of the remote vehicle's path histories is within half a lane width of the host vehicle's predicted path at a distance of evpp is a predetermined duration, such as 2 seconds.Thus, the host vehicle estimates the geometry of the lane it is traveling in based on a successful match of at least one of the remote vehicle's path histories with the host vehicle's predicted path.

[0053] Additionally, by one embodiment, when the path history of only one remote vehicle (one of the two remote vehicles 520 and 530) is within a half lane width distance from the host vehicle's predicted path 510a, the host vehicle performs additional processing when estimating the geometry of the lane. For example, if the path history 520a of the remote vehicle 520 is within a half lane width distance from the host vehicle's predicted path 510a, the host vehicle 510 performs processing on the path history 530a of the remote vehicle 530 to ensure that the remote vehicle 530 maintains a constant lateral offset from the path of the other remote vehicle. In doing so, the host vehicle 510 determines whether there is a divergence in the paths of the two remote vehicles. For example, if Figure 5 As shown, the path history of remote vehicle 530 differs from the path history of remote vehicle 520, indicating that at least one of the two remote vehicles is performing a lane change. Therefore, host vehicle 510 estimates the geometry of the lane it is traveling in based on the successful matching of the path history of at least one remote vehicle with the predicted path of the host vehicle. In the above-described processing techniques for estimating the geometry of the lane, the lane width can either be assumed to be 10 feet wide, or alternatively can be based on lane marking information and a DAS map ( Figure 2 Thus, according to one embodiment, the lane geometry is estimated based on the path history of remote vehicles within half the lane width of the predicted path of the ego vehicle. For example, a least squares fit can be performed to the path of the vehicle with the closest offset to the ego vehicle to estimate the lane geometry.

[0054] In a similar manner, the host vehicle can choose any other priority allocation scheme when assigning priorities to remote vehicles. For example, a remote vehicle can set an event flag in the BSM data packet sent to the host vehicle. For example, such a flag might be set when the remote vehicle brakes suddenly. Thus, the event flag serves as an emergency warning mechanism through which the remote vehicle can communicate with the host vehicle. Therefore, when assigning priorities to remote vehicles, the host vehicle can choose to assign the highest priority to remote vehicles that have set event flags in their BSMs.

[0055] [Estimated PV behavior]

[0056] [PV behavior]

[0057] In addition to using HV path prediction to estimate the geometry of the road ahead, the PV's path can also be used to estimate road geometry. The E-FCW logic assumes that the PV follows the geometry of the road ahead. When approaching a curve, if the PV has already entered the curve, the HV's current curvature may not accurately describe the road ahead as the PV's path. In some embodiments, the road geometry can be estimated in a manner that takes the PV's path into account.

[0058] Figure 6 is a flow chart illustrating the steps for determining PV behavior according to aspects of the present disclosure. In one embodiment, two Kalman filters and a finite difference estimator (also referred to as filters) are used to estimate PV behavior. All filters can be run on each processing cycle (e.g., a 100ms period). In S601, one filter outputs an estimate of the geometry of the path of the preceding vehicle (PV); in S603, another filter outputs an estimate of the PV's acceleration. These quantities are estimated with respect to a local HV reference (Cartesian) coordinate system (i.e., a reference frame that moves with the HV).

[0059] [Estimation of PV path]

[0060] The first Kalman filter is run on each loop.

[0061] When a PV is present, the first Kalman filter estimates the coefficients of the equation that describes the path of the PV (i.e., the lateral displacement y of the PV along the HV's forward direction as a function of x, where x is the longitudinal offset of the PV relative to the HV): y(x) = c0 + c1x + 1 / 2c2x 2 + 1 / 6c3x 3

[0062] C0, C1, C2, and C3 are parameters of the PV path in the HV reference frame. C0 represents the lateral offset of the PV path relative to the HV. C1 represents the heading of the PV path at the HV. C2 represents the curvature of the PV path at the HV. C3 represents the curvature of the PV path along the longitudinal direction of the HV. The first Kalman filter estimates these parameters as the PV state.

[0063] [Estimation of PV deceleration]

[0064] In addition to the path of the PV, the acceleration of the PV can also be determined. The motion of the preceding vehicle can be used to estimate that the PV is decelerating.

[0065] The PV acceleration is determined on every loop. Depending on the configuration options, this determination uses either a second Kalman filter or finite differences to estimate the absolute PV acceleration. The second Kalman filter state can include the acceleration, PV and HV velocities, and the relative position of the PV. The absolute longitudinal velocity is calculated from the PV relative velocity and the HV velocity.

[0066] When a PV is present, the filter estimates the longitudinal acceleration along the HV's current heading. This acceleration can be used to identify the impact of a slow RV on HV lane traffic and PV.

[0067] Through one embodiment of the present disclosure, after estimating the acceleration of a leading vehicle (PV), the ECU of the host vehicle issues a warning to the driver of the host vehicle based on a determination made by the ECU to warn the driver of the host vehicle that the driver of the host vehicle cannot perform all of the following functions: brake comfortably at a deceleration rate lower than a predetermined comfortable deceleration rate, brake within a predetermined reaction time, and avoid collision with the leading vehicle at a predetermined safety distance (or in other words, maintain a predetermined safety distance).

[0068] [Support Availability]

[0069] Support availability functions are run on every loop.

[0070] In S307, during each loop, the ECU determines whether to proceed with further RV processing for E-FCW based on: 1) the current HV speed; 2) the road type from scene recognition; and 3) user settings. In one embodiment, if the host vehicle (HV) is traveling on a highway-type road, further RV processing will be performed. RV processing may also be performed if the host vehicle is traveling at a speed greater than a predetermined speed (e.g., 40 mph) and the user settings have been configured to perform collision warning processing.

[0071] [RV Slow]

[0072] If it is determined that the collision warning is enabled ("Yes" in S309), the process continues to S311. In S311, the ECU searches for RVs that are braking hard or moving at a slow relative speed within a certain azimuth angle and have a heading direction similar to that of the HV (within a certain angle). This step removes RVs traveling on other roads from further processing.

[0073] Figure 7 is a flow chart showing the steps of determining whether an RV slows down or brakes suddenly. This step selects a target group of RVs according to the following three main steps: S701, S703, S705.

[0074] In step S701, the ECU determines from the (fully verified) RV memory buffer whether there is an RV that is one of the following: braking suddenly (i.e., an event flag is set after appropriate deceleration is detected by the RV); or slower than the HV by more than a predetermined speed (e.g., approximately 24m / s, i.e., 53mph), and has an absolute heading angle lower than a predetermined heading angle (e.g., 30°), has a heading direction that differs from the HV's heading direction by at most a maximum heading direction difference, and is within a maximum range.

[0075] The complete verification list of RVs is based on communication with the RV via radio communication. Following verification, the HV receives the current speed of each RV in the verified RV list. The ECU executes a program to determine the longitudinal and lateral offset of the RV along the HV.

[0076] In S703, the ECU finds an RV whose path history does not include a sharp turn from the subset of RVs identified in step S701. One assumption is that an RV whose path includes a sharp turn is likely to leave the highway at an exit ramp.

[0077] In one embodiment, the assumption in E-FCW is that any RV with a path history (PH) that exhibits high curvature is currently or has already left the main highway (i.e., is traveling on an off-ramp). To avoid false positives for vehicles that brake suddenly or are slow on the off-ramp or surface streets, these RVs are omitted from the subsequent support decision logic ( Figure 3 Step S317 in the process).

[0078] For the purposes of this disclosure, a "sharp" turn is one where the lateral acceleration required to traverse the turn is greater than the maximum acceleration on the highway when traveling at a predetermined minimum speed. Such a "sharp" turn is assumed to be a highway exit ramp. Step S703 adds a label to the RV whose path history does not include a "sharp" turn.

[0079] The target subset of RVs from step S703 is further reduced by the ECU finding those RVs whose heading history is similar to the local HV road geometry (eg, below the maximum difference between HV and RV headings) in S705 .

[0080] In contrast to step S703, the RV may also exit the highway on a straight (low curvature) ramp. Therefore, in one embodiment, the relative heading of the path history is also checked against the estimated road geometry. If the heading does not match, the RV is assumed to have exited the highway or is not in the HV lane.

[0081] In one embodiment, a dual-lane-changing RV is detected with a PH offset to the right of the PV and to the left of the HV (i.e., averaged to the same lane offset). In S705, the RV heading is compared to a combination of heading values: the HV's current heading, the HV's predicted heading, the PV's heading at its current location, and the PV's predicted heading. The RV's heading is then determined based on the extent of the RV's path history, the HV's speed, and the presence, location, and heading of the PV. The target subset of RVs is further reduced by the ECU finding those RVs whose headings are similar to the local HV road geometry.

[0082] Relatively long vehicle lane

[0083] In S313 , both HV and PV path information may be used to estimate lateral offset.

[0084] In step S313, the ECU processes RVs whose headings are within the same road, slow or hard braking, and not on ramps. The ECU calculates the lateral offset of the RV's path history relative to the HV lane. The lateral offset can be calculated at multiple locations (similar to the heading estimation in step S705) and then averaged.

[0085] In one embodiment, the lateral offset is approximated as the lateral distance between the PH chord of the RV and the current or projected road heading at a specific longitudinal offset along the HV heading.

[0086] Step S315 confirms that the RV is indeed on the HV road (in the HV lane or an adjacent lane) by using the additional information items. The confirmation may be based on two additional information items: (1) the PV is decelerating, and (2) there is another RV with a PH that is parallel to the path of the slow RV up to the RV's current position.

[0087] If the PV never slows down, this could mean: the slow RV is not in the PV lane; the PV is ignoring the slow preceding vehicle in its lane; the PV is changing lanes without slowing down. In one embodiment, E-FCW assumes that the slow RV is not in the PV lane.

[0088] The PV may slow down for other reasons, such as the driver's failure to maintain a steady speed. In one embodiment, E-FCW assumes that given a slow RV, the PV is most likely slowing down because traffic ahead is slower than its current speed.

[0089] In one embodiment, the ECU checks whether the PV deceleration value is below a predetermined threshold (e.g., in m / s 2 units).

[0090] Furthermore, according to one embodiment, the host vehicle performs a process of classifying the lane in which the remote vehicle (RV) is traveling. Specifically, assuming the host vehicle detects a highway-type road, the host vehicle classifies the remote vehicle as traveling in one of an "in-lane" remote vehicle (i.e., traveling in the same lane as the host vehicle) and an "in-road" remote vehicle (i.e., traveling on the same road as the host vehicle but not in the same lane).

[0091] [RV Driveway – Same Driveway]

[0092] The host vehicle classifies a remote vehicle (RV) as traveling in the same lane as the host vehicle (i.e., in the lane). In some embodiments, the remote vehicle is considered to be traveling in the same lane as the host vehicle based on the following two conditions being met. The host vehicle (HV) first determines, based on the remote vehicle's (RV's) path history, whether the remote vehicle is detected to be within half a lane width of the center of the host vehicle's lane at the following three space-time instances: at the remote vehicle's current position, at a position halfway between the remote vehicle's current position and the position of the preceding vehicle, and at the time when the remote vehicle is at the preceding vehicle's current position. Additionally, as a second condition, the host vehicle classifies the remote vehicle as an in-lane remote vehicle based on the remote vehicle's heading angle being within 45° of the host lane's heading along the remote vehicle's path history.

[0093] [RV lanes – different lanes]

[0094] The host vehicle classifies a remote vehicle as an on-road remote vehicle (i.e., a remote vehicle traveling on the same road as the host vehicle but not in the same lane). The host vehicle first determines, based on the remote vehicle's path history, whether the remote vehicle is detected to be within two lane widths of the host vehicle's lane center at the following three spatiotemporal instances: at the remote vehicle's current position, at a position halfway between the remote vehicle's current position and the position of the preceding vehicle, at the time the remote vehicle is at the preceding vehicle's current position, and at the time the remote vehicle is at the host vehicle's current position. Furthermore, as a second condition, the host vehicle classifies the remote vehicle as an on-road remote vehicle based on the remote vehicle's heading angle being within 45° of the host lane's heading along the remote vehicle's path history.

[0095] HMI

[0096] In step S317, the ECU considers the risk posed by all RVs that meet the following characteristics: slow or sudden braking, not on a ramp, and heading in the road. If there is a slow RV, if the PV is decelerating, the RV is assumed to be in the same lane as the HV.

[0097] Figure 8 is a flowchart showing the steps of executing the decision logic. In S801, the ECU determines whether the RV is slow, on the same road as the HV and not on an exit ramp. When the conditions in S801 are met ("Yes" in S801), the ECU determines in S803 whether the RV is in the same lane as the HV, or in S805 whether the RV is in an adjacent lane (left or right). In S807, the ECU determines whether the PV is decelerating. If the RV is in the same lane or an adjacent lane, but the PV is not decelerating ("No" in S807), the ECU displays a visual information message in S809. Otherwise ("Yes" in S807), when the PV is decelerating, an alarm will be presented as an audio and visual message in S811.

[0098] Depending on the RV relative speed, E-FCW will be supported (1) immediately or (2) based on TTC / distance to PV or safe following distance of RV.

[0099] In step S319, the ECU requests the HMI from the HMI arbitration block with hysteresis. This step avoids repeated false alarms and avoids repeated positive alarms that may annoy the driver. In one embodiment, in S319, if the RV is estimated to be in the HV lane using step S315, the display process can be executed immediately.

[0100] E-FCW can be elevated from "info" (visual only) to "caution / alert" (visual and audible) at any time. However, unless elevated, the HMI visual information message is only issued once every predetermined seconds. This is to avoid annoying the driver in the event of repeated false alarms or if the driver has received the message but still chooses to drive aggressively.

[0101] The ECU may issue audible and visual HMI (independently) warnings for specific durations.

[0102] In addition, through one embodiment, the ECU can also issue a warning message based on the remote vehicle coming to a stop (i.e., the remote vehicle is stopped), or the deceleration rate of the remote vehicle in the lane and / or the deceleration rate of the preceding vehicle in the lane is greater than a predetermined deceleration rate (e.g., a deceleration rate corresponding to a vehicle sudden braking scenario (such as an emergency electronic brake light condition)).

[0103] [Processing circuit]

[0104] Each of the functions of the described embodiments may be implemented by one or more processing circuits. The processing circuits include programmed processors (e.g., Figure 9 Processor 903 in ), because the processor includes circuitry. Processing circuitry also includes devices such as application specific integrated circuits (ASICs) and circuit components arranged to perform the recited functions.

[0105] The various features discussed above may be implemented by a computer system (or programmable logic). Figure 9 Such a computer system 901 is shown. In one embodiment, the computer system 901 is a specific, dedicated machine, while the processor 903 is programmed to perform placement of the bolt, alignment and positioning of the probe within the bolt, and the like.

[0106] The computer system 901 includes a disk controller 906 coupled to the bus 902 to control one or more storage devices for storing information and instructions, such as a magnetic hard disk 907, and a removable media drive 908 (e.g., a floppy disk drive, a read-only optical drive, a read / write optical drive, a jukebox, a tape drive, and a removable magneto-optical drive). Storage devices can be added to the computer system 901 using an appropriate device interface (e.g., small computer system interface (SCSI), integrated device electronics (IDE), enhanced IDE (E-IDE), direct memory access (DMA), or Ultra-DMA).

[0107] The computer system 901 may also include a dedicated logic device (eg, an application specific integrated circuit (ASIC)) or a configurable logic device (eg, a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA)).

[0108] The computer system 901 may also include a display controller 909 coupled to the bus 902 to control a display 910 for displaying information to a computer user. The computer system includes input devices such as a keyboard 911 and a pointing device 912 for interacting with the computer user and providing information to the processor 903. The pointing device 912 may be, for example, a mouse, a trackball, a finger for a touch screen sensor, or a pointing stick for communicating directional information and command selections to the processor 903 and for controlling cursor movement on the display 910.

[0109] Processor 903 executes one or more sequences of one or more instructions contained in a memory, such as main memory 904. Such instructions may be read into main memory 904 from another computer-readable medium, such as hard disk 907 or removable media drive 908. One or more processors in a multi-processing arrangement may also be employed to execute the sequences of instructions contained in main memory 904. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions. Thus, embodiments are not limited to any specific combination of hardware circuitry and software.

[0110] As described above, the computer system 901 includes at least one computer-readable medium or memory for storing instructions programmed according to any teachings of the present disclosure and for containing data structures, tables, records, or other data described herein. Examples of computer-readable media are optical disks, hard disks, floppy disks, magnetic tapes, magneto-optical disks, PROMs (EPROMs, EEPROMs, Flash EPROMs), DRAMs, SRAMs, SDRAMs, or any other magnetic media, optical disks (e.g., CD-ROMs) or any other optical media, punch cards, paper tape, or other physical media with perforated patterns.

[0111] The present disclosure includes software for controlling the computer system 901, for driving one or more devices used to implement the features of the present disclosure, and for enabling the computer system 901 to interact with human users, stored on any one or combination of computer-readable media. Such software may include, but is not limited to, device drivers, operating systems, and application software. Such computer-readable media also include computer program products of the present disclosure for performing all or part of the processing performed in implementing any portion of the present disclosure (if the processing is distributed).

[0112] The computer code device of the present embodiment can be any interpretable or executable code mechanism, including but not limited to scripts, interpretable programs, dynamic link libraries (DLLs), Java classes, and complete executable programs. In addition, part of the processing of the present embodiment can be distributed to achieve better performance, reliability, and / or cost.

[0113] As used herein, the term "computer-readable medium" refers to any non-transitory medium that participates in providing instructions to processor 903 for execution. Computer-readable media can take many forms, including but not limited to non-volatile media or volatile media. Non-volatile media include, for example, optical, magnetic, and magneto-optical disks, such as hard disk 907 or removable media drive 908. Volatile media include dynamic memory, such as main memory 904. In contrast, transmission media include coaxial cables, copper wire, and fiber optics, including the wires that make up bus 902. Transmission media can also take the form of acoustic or light waves, such as those generated during radio wave and infrared data communications.

[0114] Various forms of computer-readable media may be involved in implementing one or more sequences of one or more instructions to the processor 903 for execution. For example, the instructions may initially be carried on a disk of a remote computer. The remote computer may remotely load instructions for implementing all or part of the present disclosure into a dynamic memory and send the instructions over a telephone line using a modem. A modem local to the computer system 901 may receive data over the telephone line and place the data on the bus 902. The bus 902 transfers the data to the main memory 904, from which the processor 903 retrieves and executes the instructions. The instructions received by the main memory 904 may optionally be stored in the storage device 907 or 908 before or after execution by the processor 903.

[0115] Computer system 901 also includes a communication interface 913 that is coupled to bus 902. Communication interface 913 provides a two-way data communication coupled to a network link 914, which is connected to, for example, a local area network (LAN) 915, or is connected to another communication network 916, such as the Internet. For example, communication interface 913 can be a network interface card (NIC) attached to any packet-switched LAN. As another example, communication interface 913 can be an integrated services digital network (ISDN) card. Wireless links can also be implemented. In any such implementation, communication interface 913 sends and receives electrical, electromagnetic or optical signals that carry digital data streams representing various types of information.

[0116] Network link 914 typically provides data communication to other data devices through one or more networks. For example, network link 914 can provide a connection to another computer through a local network 915 (e.g., a LAN) or through equipment operated by a service provider that provides communication services through communication network 916. Local network 914 and communication network 916 use, for example, electrical, electromagnetic, or optical signals that carry digital data streams and an associated physical layer (e.g., CAT5 cable, coaxial cable, fiber optic cable, etc.).

[0117] Computer system 901 can send and receive data (including program code) through networks 915 and 916, network link 914, and communications interface 13. In addition, network link 914 can provide a connection through LAN 915 to a mobile device 917, such as a personal digital assistant (PDA), laptop computer, or cell phone.

[0118] In light of the above teachings, many modifications and variations of the present invention are possible. Therefore, it should be understood that within the scope of the claims, the present invention may be practiced otherwise than as specifically described herein. It should be noted that, as used in the specification and claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

Claims

1. A method of generating a collision warning to a driver of a host vehicle, the method comprising: detecting, by processing circuitry, the presence of a slow, remote vehicle ahead of the host vehicle; tracking, by the processing circuit, a speed of an immediately preceding vehicle in front of the host vehicle; confirming, by the processing circuitry, that the slow remote vehicle is affecting lane traffic speed of the host vehicle by detecting that the immediately preceding vehicle is decelerating; displaying, by the processing circuitry, an information message indicating the presence of the slow remote vehicle when the slow remote vehicle is detected and is tracking the immediately preceding vehicle and when the immediately preceding vehicle is detected not to be decelerating; as well as The collision warning is output by the processing circuit as an audible and visual message when the slow remote vehicle is detected and the immediately preceding vehicle is decelerating.

2. The method of claim 1, further comprising: establishing wireless communication with a remote vehicle; determining, by the processing circuitry based on information received via the wireless communication, whether the remote vehicle is on the same road as the host vehicle; determining, by the processing circuitry based on the information, whether the remote vehicle is on an exit ramp; as well as When it is determined that the remote vehicle is on the same road but not on an exit ramp, it is determined whether the remote vehicle is at a slow speed.

3. The method of claim 1 , further comprising: determining, by the processing circuitry, whether a tracking history for the remote vehicle is available; estimating, by the processing circuitry, a lane geometry based on the tracking history of the remote vehicle; as well as A determination is made, by the processing circuit, whether a path derived based on the path history of the remote vehicle matches a predicted path of the host vehicle.

4. The method of claim 3, further comprising: The geometry of the lane is determined by the processing circuit based on a map when the tracking history of the remote vehicle is not available.

5. The method of claim 3, further comprising: determining the road type by performing scene recognition using the processing circuitry, Wherein when the road type is determined to be a highway road type, estimating the geometry of the lane based on the tracking history of the remote vehicle is performed.

6. The method of claim 3, wherein estimating the geometry of the lane based on the tracking history of the remote vehicle by the processing circuit is performed when the host vehicle is traveling at greater than a predetermined speed.

7. The method of claim 1 , further comprising: establishing wireless communications with a plurality of remote vehicles; as well as The processing circuit searches the plurality of remote vehicles for a relatively slow remote vehicle that is within a predetermined heading angle and has a heading that differs from a heading of the host vehicle by at most a maximum heading difference and is within a maximum range.

8. The method of claim 7, wherein the processing circuit determines the difference from the heading of the host vehicle by comparing the heading of the remote vehicle to a combination of heading values, the combination of heading values ​​comprising: The current heading of the host vehicle, the predicted heading of the host vehicle, the heading of the preceding vehicle at its current position, and the predicted heading of the preceding vehicle.

9. The method of claim 7, further comprising: The remote vehicle is confirmed, by the processing circuit, to be in a host vehicle path based on determining that the leading vehicle is decelerating and there is another remote vehicle having a heading parallel to a path of the slower remote vehicle until the remote vehicle's current position.

10. A method of generating a collision warning to a driver of a host vehicle, the method comprising: detecting, by processing circuitry, the presence of a slow, remote vehicle ahead of the host vehicle; tracking, by the processing circuit, a speed of an immediately preceding vehicle in front of the host vehicle; confirming, by the processing circuitry, that the slow remote vehicle is affecting lane traffic speed of the host vehicle by detecting that the immediately preceding vehicle is decelerating; displaying, by the processing circuitry, an information message indicating the presence of the slow remote vehicle when the slow remote vehicle is detected and is tracking the immediately preceding vehicle; as well as outputting, by the processing circuitry, the collision warning as an audible and visual message when the slow remote vehicle is detected and the immediately preceding vehicle is decelerating, When the remote vehicle is at a slow speed, an information message indicating that the remote vehicle is at a slow speed is displayed every predetermined seconds.

11. A system for generating a collision warning to a driver of a host vehicle, the system comprising: Onboard sensors of the host vehicle for tracking the vehicle immediately ahead; a wireless communication circuit for establishing wireless communication with a remote vehicle; a processing circuit, the processing circuit being configured to: detecting the presence of a slow remote vehicle ahead of the host vehicle; tracking the speed of an immediately preceding vehicle in front of the host vehicle; confirming that the slow remote vehicle is affecting lane traffic speed of the host vehicle by detecting that the immediately preceding vehicle is decelerating; displaying an information message indicating the presence of the slow remote vehicle when the slow remote vehicle is detected and is tracking the immediately preceding vehicle and when the immediately preceding vehicle is detected not to be slowing down; as well as When the slow remote vehicle is detected and the immediately preceding vehicle is decelerating, the collision warning is output as an audible and visual message.

12. The system of claim 11 , wherein the processing circuit is further configured to: establishing wireless communication with a remote vehicle; determining, by the processing circuitry based on information received via the wireless communication, whether the remote vehicle is on the same road as the host vehicle; determining, by the processing circuitry based on the information, whether the remote vehicle is on an exit ramp; as well as When it is determined that the remote vehicle is on the same road but not on an exit ramp, it is determined whether the remote vehicle is at a slow speed.

13. The system of claim 11 , wherein the processing circuit is further configured to: determining whether a tracking history for the remote vehicle is available; estimating a lane geometry based on the tracking history of the remote vehicle; as well as A determination is made as to whether a path derived based on the path history of the remote vehicle matches a predicted path of the host vehicle.

14. The system of claim 13, wherein the processing circuit is further configured to: When the tracking history of the remote vehicle is not available, the geometry of the lane is determined based on a map.

15. The system of claim 13, wherein the processing circuit is further configured to: determining the road type by performing scene recognition using the processing circuitry, Wherein when the road type is determined to be a highway road type, estimating the geometry of the lane based on the tracking history of the remote vehicle is performed.

16. The system of claim 13, wherein the estimating of the geometry of the lane based on the tracking history of the remote vehicle by the processing circuit is performed when the host vehicle is traveling at greater than a predetermined speed.

17. The system of claim 11, wherein the processing circuit is further configured to: establishing wireless communications with a plurality of remote vehicles; and A relatively slow remote vehicle is searched among the plurality of remote vehicles, the relatively slow remote vehicle being within a predetermined azimuth and having a heading that differs from a heading of the host vehicle by at most a maximum heading difference and within a maximum range.

18. The system of claim 17, wherein the processing circuit is further configured to determine a difference from the heading of the host vehicle by comparing the heading of the remote vehicle to a combination of heading values, the combination of heading values ​​comprising: The current heading of the host vehicle, the predicted heading of the host vehicle, the heading of the preceding vehicle at its current position, and the predicted heading of the preceding vehicle.

19. The system of claim 17 , wherein the processing circuit is further configured to confirm that the remote vehicle is in a host vehicle path based on determining that the preceding vehicle is decelerating and there is another remote vehicle having a heading until the remote vehicle's current position is parallel to the path of the slower remote vehicle.

20. The system of claim 11, wherein the processing circuit is further configured to display an information message indicating that the remote vehicle is slowing every predetermined seconds when the remote vehicle is slowing.

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