Positioning system based on geofencing framework
11543834 · 2023-01-03
Assignee
Inventors
Cpc classification
G01S5/0264
PHYSICS
H04W4/44
ELECTRICITY
G01C21/188
PHYSICS
G01S5/0072
PHYSICS
G01C21/12
PHYSICS
G05D1/027
PHYSICS
G08G1/0129
PHYSICS
G08G1/207
PHYSICS
H04W4/021
ELECTRICITY
International classification
G01C21/16
PHYSICS
G01S19/49
PHYSICS
G01S5/00
PHYSICS
H04W4/44
ELECTRICITY
H04W4/021
ELECTRICITY
G01C21/12
PHYSICS
Abstract
This provides methods and systems for the global navigation satellite system (GNSS) combined with the dead-reckoning (DR) technique, which is expected to provide a vehicle positioning solution, but it may contain an unacceptable amount of error due to multiple causes, e.g., atmospheric effects, clock timing, and multipath effect. Particularly, the multipath effect is a major issue in the urban canyons. This invention overcomes these and other issues in the DR solution by a geofencing framework based on road geometry information and multiple supplemental kinematic filters. It guarantees a road-level accuracy and enables certain V2X applications which does not require sub-meter accuracy, e.g., signal phase timing, intersection movement assist, curve speed warning, reduced speed zone warning, and red-light violation warning. Automated vehicle is another use case. This is used for autonomous cars and vehicle safety, shown with various examples/variations.
Claims
1. A method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle, said method implemented by one or more processors, said method comprising: receiving vehicle states for said vehicle, said vehicle states including at least data of a position, a speed, a heading angle and a yaw rate of said vehicle, said yaw rate having a yaw rate bias; removing said yaw rate bias of said yaw rate; responsive to removing said yaw rate bias of said yaw rate, determining whether a reference road exists, said reference road providing data of at least a road heading angle and a road curvature; in case said reference road exists, determining whether said existing reference road is valid; in case said reference road does not exist or said existing reference road is invalid, searching for said reference road; determining a reference yaw rate based on said road curvature and said speed of said vehicle; determining whether a yaw rate error between said yaw rate and said reference yaw rate is less than a yaw rate threshold; in case said yaw rate error is less than said yaw rate threshold, forcing said heading angle of said vehicle to said road heading angle; updating said vehicle states; determining geofencing conditions of said position, speed, heading angle and yaw rate of said vehicle; determining whether said geofencing conditions are met; and in case said geofencing conditions are met, applying geofencing to limit said position of said vehicle between road boundaries of said reference road.
2. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein said road vehicle navigation system works with or communicates with a global navigation satellite system.
3. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein said vehicle is interior to said reference road.
4. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein a distance from said vehicle to a next intersection is greater than a first threshold.
5. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein said vehicle's speed is greater than a second threshold.
6. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein applying geofencing comprises: timely geofencing.
7. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein applying geofencing comprises: predicted geofencing.
8. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein said method comprises: determining an incorrect position of said vehicle and correcting the determined position for said vehicle based on reducing a lateral error.
9. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein in case said reference road does not exist or said existing reference road is invalid, said search for said reference road comprises: determining candidate reference roads where said vehicle's position is interior to end points of said candidate reference roads; determining, from said candidate reference roads, a candidate reference road satisfying a heading error below a threshold; and adjusting an order of said end points to be consistent with a travel direction of said vehicle.
10. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein said method comprises: determining a lateral error for said vehicle.
11. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein said method comprises: in case said reference road is not found based on said search, outputting said data of said vehicle's position to said upper layer of said road vehicle navigation system for said vehicle.
12. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein said method comprises: determining a longitudinal error for said vehicle.
13. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein said method comprises: determining a predicted position for said vehicle based on at least one of lateral correction and longitudinal correction.
14. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein said method comprises: determining an average value of said yaw rate bias within a moving time window, and correcting said yaw rate bias based on said determined average value.
15. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein said method comprises: determining a sensor temperature, and determining said yaw rate bias that varies with said sensor temperature.
16. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein said method comprises: determining vibration or noise for removing said yaw rate bias.
17. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein said method comprises: applying a security layer for said road vehicle navigation system for said vehicle.
18. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein said method comprises: applying an application layer for said road vehicle navigation system for said vehicle.
19. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein said method comprises: applying a network layer for said road vehicle navigation system for said vehicle.
20. The method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle as recited in claim 1, wherein said method comprises: applying a physical layer for said road vehicle navigation system for said vehicle.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
(85) Descriptions of the Geofencing Framework for Enhancing Positioning Accuracy:
(86) Overview:
(87) The main processes of this invention are described below, that is, 1) geofencing to correct the vehicle position, when the vehicle has crossed or is predicted to cross the road boundary, 2) yaw rate bias removal, 3) heading angle correction based on the yaw rate error, and 4) retrospective corrections for lane change. A detailed description for each is provided below.
(88) Geofencing:
(89) The geofencing is to limit the location where the vehicle can exist within the road defined between the road boundaries. It is divided into two types: 1) timely geofencing, which occurs on roads distant from intersections and shifts the lateral position of the vehicle to the last lane as soon as the vehicle crosses a road boundary, and 2) predicted geofencing, which occurs at turns at intersections and corrects both the lateral and longitudinal offsets during the turn maneuver, if the error between the predicted turn path and the reference turn path exceeds a tolerance in either direction.
(90)
(91)
(92) Yaw Rate Bias Removal:
(93) The yaw rate sensor contains a bias, and it varies by sensor temperature. It is crucial to minimize such an error for a better heading angle result from the yaw rate integration. This is achieved by calculating the average of the bias within a moving time window when the vehicle is stationary, and subtract the value from the raw value:
(94)
(95) where r.sub.i,
(96) Heading Angle Correction Based on Yaw Rate Error
(97) It is assumed that the vehicle is going to remain in the same lane, if the error between the vehicle yaw rate and the reference yaw rate is less than a threshold, or:
|r−r.sub.ref|≤Δr.sub.th
(98) where r.sub.ref=cU (c: road curvature, and U: vehicle speed) and Δr.sub.th is a threshold. If this condition is met, the vehicle heading angle is set to the road heading angle to eliminate the heading error that is introduced by the yaw rate integration.
(99) Retrospective Integrations
(100) A drawback of the heading angle correction in here is that when a lane change occurs the vehicle position would be different from the true position, due to the forced heading angle, which does not allow lateral movement relative to the road and the heading angle offset due to a lack of yaw rate integration. This is corrected by performing a yaw rate integration from a past point before such a maneuver occurred. This is visualized in
(101) System Structure
(102) A system structure augmented by the enhanced positioning system in the onboard unit (OBU) is shown in
(103)
(104) Brief descriptions of all blocks in the flowchart are provided below:
(105) Block 1:
(106) The vehicle states of interests are the position, heading angle, speed, and yaw rate. If the vehicle position is in the geographical coordinates, they need to be transformed into Cartesian coordinates for the rest of the procedure.
(107) Block 2:
(108) The yaw rate bias removal explained in section above is performed in this block.
(109) Block 3:
(110) Determine if a reference road is available or not. The reference road is a line or curve connecting two adjacent intersections used to correct the vehicle position and heading, when necessary, providing necessary information for this purpose, such as the coordinates of the end points of the reference road, road heading angle, curvature, and road width.
(111) Block 4:
(112) If there is no reference road is available, one is searched for by the following steps: Step 1—Find candidates for the reference road where the vehicle position is interior to the end points, with tolerances Step 2—Find the closest candidate among those satisfying a heading error below a threshold Step 3—Adjust the order of the end points to be consistent with the travel direction of the vehicle
(113) Whether a point is interior or exterior to the reference road or not is determined by a flag, defined as:
(114)
(115) The geometric interpretation of the flag value is described in
(116) Block 5:
(117) A valid reference road is one with the vehicle is interior to it, and the difference between the vehicle heading and road heading is less than a threshold.
(118) Block 6:
(119) If a reference road is found in Block 4, go to Block 8. Otherwise, the rest of the procedure will be skipped. (See the flowchart in
(120) Block 7:
(121) A lane change is detected, if a duration in which the absolute value of the yaw rate continuously exceeds a threshold becomes longer than a specified time, within a time window.
(122) Block 8:
(123) Retrospective integrations of the speed and yaw rate are performed, if a lane change is detected to correct the vehicle position and heading angle, which may contain errors due to the fixed heading angle in Block 10, from the previous time step.
(124) Block 9:
(125) The yaw rate error test described in section above is performed.
(126) Block 10:
(127) Depending on the result from Block 9, the vehicle heading angle is forced to the road heading angle.
(128) Block 11:
(129) Stochastic filters (e.g., Kalman filters) is applied to update the vehicle states, i.e., position, velocity, acceleration, and heading angle. This process involves a sensor fusion between the GNSS and DR, if the GNSS signal error is within a valid range. Otherwise, only DR solution is updated.
(130) Block 12:
(131) Before outputting the vehicle states to the upper layer in the OBU, the validity of the vehicle position is evaluated using the reference road found in Block 4.
(132) Block 13:
(133) The geofencing conditions described in section above are evaluated.
(134) Block 14:
(135) If a geofencing condition is met, the geofencing is performed to correct the vehicle position.
(136) Block 15:
(137) Updated vehicle position data are outputted to the upper layer of the system.
(138) As shown below, for other parts of our system/inventions, we can integrate all the components above to make the operation of the vehicle much safer for self-driving or autonomous vehicles, as well as for human-operated cars/vehicles. (
Prior Embodiments of the Inventions in the Parent Cases
(139) Here are some of the prior embodiments of the inventions in the parent cases:
(140) The V2X applications, such as forward collision warning, electronic emergency brake light, left turn assist, work zone warning, signal phase timing, and others, mainly rely on a GNSS positioning solution transmitted via the Dedicated Short-Range Communications (DSRC) to/from the roadside units and onboard units in other V2X-enabled vehicles. However, the positioning solution from a GNSS may be deteriorated by noise and/or bias due to various error sources, e.g., time delay, atmospheric effect, ephemeris effect, and multipath effect. This invention offers a novel quality filter that can detect noise and the onset of drift in GNSS signals by evaluating up to four metrics that compare the qualities of kinematic variables, speed, heading angle change, curvature, and lateral displacement, obtained directly or derived from GNSS and onboard vehicle sensors.
(141) Here, we describe some of the embodiments of our system and method:
(142) Let's look at the details of one method:
(143) Three metrics are considered every time a new GNSS position estimate is provided, and each metric compares kinematic variables obtained from the GNSS and vehicle sensors. When these metrics appear to be within tolerances, the GNSS signal is considered valid.
(144) Each metric is explained in detail in the following sections:
(145) First Metric:
(146) The first metric, M1, compares speed values from GNSS with that from the vehicle sensor sampled within a moving time window of an interval between a past time and the current time. It is described by the ratio:
(147)
(148) where the numerator is the number of occurrences that the speed difference between the two sensors is less than a threshold value, ΔV.sub.thres, the denominator is the number of time stamps in the moving window, t.sub.c is a current time stamp, and ΔT.sub.1 is the interval of the moving window. The condition that this metric must satisfy for a GNSS signal to be valid is:
M.sub.1(t.sub.c)≥p.sub.1 (2)
(149) where p1 is a constant threshold value which is not greater than 1.
(150) Second Metric:
(151) The second metric, M2, compares the changes of the heading angle from the GNSS and that derived from yaw rate sensor signals. This comparison is to be made for all combinations of time pairs within a moving time window. This time window is similar to the one in the first metric, but its window size may be different. This metric accounts for two characteristics: 1) overall heading change (i.e., final offset) and 2) fluctuations (i.e., smoothness).
(152) The GNSS heading change between two time points is calculated by either:
(153)
(154) for geographic coordinates, where λ is latitude and φ is longitude for the geographic coordinate system, and i and j are the indices of two time stamps in the current moving window, i.e., (t.sub.i,t.sub.j)∈[t.sub.c−ΔT.sub.2,t.sub.c], t.sub.i<t.sub.j
(155) where ΔT.sub.2 is the size of the moving window.
(156) Or, on the other hand, a heading change can be calculated by integrating the yaw rate using the trapezoid rule:
(157)
(158) where rk is the yaw rate at t=tk, and Δt=t.sub.k−t.sub.k-1.
(159) As a result, the second metric is defined by:
(160)
(161) and for a valid GNSS signal,
M.sub.2(t.sub.c)<p.sub.2 (7)
(162) where p2 is an angular threshold representing a maximum allowable value for the sum of the absolute values of the heading change differences.
(163) Third Metric:
(164) The third metric, M3, evaluates the positional stability of GNSS data by comparing the curvature of the GNSS trajectory and a derived trajectory from the speed and yaw rate sensors on the vehicle.
(165) The GNSS curvature at time ti is approximated by using heading angles and speeds from two consecutive time stamps:
c.sub.GNSS.sup.i-1,i=ΔH.sub.GNSS.sup.i-1,i/L.sub.GNSS.sup.i-1,i (8)
(166) where c.sub.GNSS.sup.i is the curvature of the GNSS trajectory, ΔH.sub.GNSS.sup.i-1,i is the heading change defined by:
ΔH.sub.GNSS.sup.i-1,i=H.sub.GNSS.sup.i−H.sub.GNSS.sup.i-1 (9)
where
(167)
(168) and L.sub.GNSS.sup.i-1,i is the distance traveled in [t.sub.i-1,t.sub.i], or
L.sub.GNSS.sup.i-1,i=V.sub.GNSS.sup.i-1.Math.(t.sub.i−t.sub.i-1) (11)
(169) Applying the above calculations to each time stamp in a target moving window ΔT.sub.3 we can find the average GNSS curvature at the current time for that moving window, i.e.,
(170)
(171) On the other hand, another curvature derived from the vehicle sensors is calculated as follows:
(172)
(173) Consequently, the third metric and condition for a valid GNSS signal are described as
(174)
(175) where p3 is a threshold for this metric.
(176) Fourth Metric:
(177) The fourth metric also considers positional stability, but is used only if the third metric fails to satisfy its validity condition. It calculates a lateral offset created between the two trajectories in the same moving window for the third metric.
(178) Using the GNSS data, the lateral displacement is calculated by
y.sub.GNSS(t.sub.c)=x.sub.GNSS sin(Δψ.sub.GNSS/2) (15)
(179) where x.sub.GNSS and y.sub.GNSS are the longitudinal and lateral displacements, respectively, and Δψ.sub.GNSS is the heading change between the first and last time stamps of the moving time window.
(180) On the other hand, it is calculated using the vehicle sensors by the following equations:
(181)
(182) The offset between these is used as the fourth metric:
(183)
(184) where p4 is a threshold that this metric must satisfy for a GNSS signal to be considered valid.
(185) Implementation of the GNSS Quality Filter
(186) The overall GNSS quality assessment system operates as depicted in
(187) An example situation where this system is useful is driving in a city in which GNSS signals may be corrupted occasionally due to the multipath effect that occurs in the urban canyon. In such a situation, it is important to be able to accept a GNSS signal when it is valid and discard otherwise.
(188) Basically, we want to make sure that we do not get erroneous results or get overconfident on some results, by reducing the numbers of false positives and negatives. So, the reliability of result and confidence on system go up together, and we can view the problem and double-check the results in at least 3 ways, with a 4.sup.th way, as a backup for verification of the 3.sup.rd method.
(189) This is very important, as any false positives and negatives, with the cars in the road, could be fatal or very expensive, in terms of human well-being and properties. On the other hand, any correction and verification can save lives and properties or reduce damages drastically. In addition, it can supplement the human judgements and response, to correct or reduce the errors, to avoid accidents, as a preventive measure for human driver.
(190) This is based on expectation and prediction of a behavior for a vehicle or the trajectory, to conclude from observations what it should be or do at a given moment. Any help from mathematical modeling of the situation and environment would be useful for the driver, or for autonomous car. This is especially true, when we look at many cars or many drivers, as the chance of accident with or without the driver is usually high at any given moment for some car in the city. The following figures give more details and components of the system.
(191) As one embodiment, for one example, based on
(192) As other embodiments, we have the following choices or options:
(193) wherein said first threshold is not greater than 1.
(194) getting data for said vehicle speed.
(195) getting data for said vehicle direction.
(196) getting data for said vehicle yaw rate.
(197) correcting said vehicle's direction.
(198) warning an operator.
(199) warning a driver.
(200) warning headquarters.
(201) warning a central server.
(202) warning another driver.
(203) warning another car.
(204) communicating with pedestrians.
(205) communicating with cloud.
(206) communicating with server farms.
(207) communicating with police.
(208) communicating with a grid.
(209) communicating with a secured network.
(210) communicating with outside car sensors.
(211) resolving conflict between sensors and/or received data.
(212) Here are the components and their variations for the invention, for the system and method for positioning quality filter for the V2X technologies:
(213) From Prior Teachings:
(214) The teachings of the parent cases, “Methods of tracking pedestrian heading angle using smart phones data for pedestrian safety applications” and “System and method for creating, storing, and updating local dynamic MAP database with safety attribute”, are included here, as well:
(215) Here, we describe some of the embodiments of our system and method:
(216) Let's look at the details of one method:
(217) MAP Generation: MAP Generation based on vehicle data, included in Basic Safety Message (BSM) or equivalent message(s). a. Listen to all the BSMs transmitted in the given region, and based on what is the intended region of map, filter out the BSM data which falls outside this region. The intended region of map can also be defined adaptively, using the speed profiles data in each road segment of interest. For example, a high average speed road segment will require more map coverage than a low average speed road segment. b. Store location (concise), Heading, Speed, and timestamp of each of the BSM. If the vehicle provides PH (Path History or trajectory or breadcrumb trail points) (concise points), check the accuracy/confidence of the PH points. In case the accuracy is good (say better than e.g. 0.4 m (or meter)), store them instead of actual locations reported by the vehicle. For example, from the current location and velocity, we can calculate the next point in time, or we can extrapolate the next point, based on the last N points. For example, one can assume a line or higher order curves, or polynomials of degree M, to fit the points in the formula and get the coefficients. Once the coefficients are known, the next point can be extrapolated. For example, the accuracy can be measured from the distance of a given point to the line or curve of trajectory. For an embodiment, the accuracy threshold is a fixed number or distance. For an embodiment, the accuracy threshold is a variable number or distance. That can be dependent on the velocity of the vehicle. For example, the higher the velocity, the higher the threshold, e.g., with a linear relationship. Otherwise, use the location details provided by the vehicle and generate the PH (Concise) points for the vehicle, and store these values. c. Start generating a Temporary Map, once the stored data has sufficient number of vehicles, Q (say, e.g., 1000 vehicles), or for example, length of time for monitoring, T, as a threshold, e.g., one-week worth of data, to make sure we have enough data points for our analysis and determination. In one embodiment, we can use any logical combination of thresholds or conditions on Q and T, e.g., using AND or OR.
(218) Here are the steps of one embodiment of our method: (see
(219) Step 1: Generating Lanes: (see
(220) e.g. Resultant Weight:
(221)
(222) Another method is to use the first order statistical combination. Then, we have:
w_r=1/(((1/w1)*(1/w2))/((1/w1)+(1/w2))) In general, we have as a function (F) of w1 and w2:
w_r=F(w1,w2) First, combine the paths which start and end with the same heading angles. Second, combine the parts of paths of the vehicles which have the same headings in that part. For the combined paths which are headed in the same direction, update the weights (using the above formula) of the paths (or parts of the paths). Detect Lane changes in the captured/stored data, and discard that data (either part or full info from that vehicle). Different methods of detecting lane changes have been proposed in previous inventions (see the parent applications). Any of those methods can be used here for the detection of lane changes. In addition, the statistical Median operation can be also used to filter outliers in positions and paths. It also can help for the lane change detection. In one embodiment, generally, the outliers may be bad data points, and cannot be relied on. So, we filter them out. In one embodiment, assuming the normal distribution, if any data point is beyond 2 standard deviations, from the peak, it is considered as the outlier point, and gets discarded. In one embodiment, a vehicle is monitored from its center, as a point, for tracking purposes. In one embodiment, a vehicle is monitored from the middle front point and the middle back point, as 2 points, for tracking purposes. So, for example, if one point (e.g. the front point) is in one lane and the other point is in another lane, that may indicate transition between lanes or changing lanes, if the difference is above a threshold, which is measured with respect to the distance perpendicular to the lane direction, or with respect to the angle relative to the lane direction.
(223) Step 2: Determining Intersection Region and Splitting the lanes: (see
(224) Intersection Diamond region can be identified from the above data in the following ways: (see
(225) 1. Using Speed profiles of the vehicles.
(226) 2. Using Heading angles of the vehicles.
(227) 3. Using Intersection of Lanes (generated from Vehicle Travel paths).
(228) Now, let's look at different methods in details:
(229) Method 1: Using Speed Profiles of the Vehicles: (See
(230) This applies on other road segment of interest, that show queue of vehicles stopped, with profile history of coming to stop. Another way to look at it is to detect an area where there is no stopped vehicle position density. (This is the intersection diamond region.)
(231) Method 2: Using Heading Angles: Consider all the vehicles which are traversing on each of the lanes. Of the vehicles traversing on each lane, select the vehicles which have executed a change in the Heading angle (by more than α.sub.1, e.g. 20°), where some of the other vehicles near to that location were traveling straight. Of all the above selected vehicles, select the location where they executed this change. Of all these locations, discard the outliers which fall outside of e.g. 5% of the statistical limit, or tail of the distribution curve, as anomalies or outliers. Calculate the average of these remaining locations. This average location provides the lane boundary of the selected lane. In one embodiment, the average is based on average of X and Y coordinates, on 2-D coordinates. In one embodiment, the average is based on weighted average of X and Y coordinates, emphasizing some data over the others. For example, one can have more weights for more reliable data. The GPS location of each of the lanes, constructed based on the above steps, provides the outer edge of the Intersection Diamond region.
(232) Method 3: Using Intersection of Lanes (Generated from Vehicle Travel Paths): (See
(233) Step 3: Determining Lane Type (Ingress/Egress): (See
(234) We use the following methods:
(235) Method 1: Using difference in angle in Vehicle heading and Lane-Heading (Waypoint0): For each of the lanes, calculate the angle of Waypoint0 (w.r.t. Waypoint1). Calculate the difference in heading of Waypoint0 and Heading of vehicle (α.sub.6). If the Difference α.sub.6 falls between say, e.g., {[0°-90°] U [270°-360°]}, as the union of sets or ranges of angles (or the angle locating in the union of the first and fourth quadrants in the 2-D coordinate system), then given lane is an Egress lane, else (otherwise), it is an Ingress lane. Based on the vehicles heading angle at the 1st waypoint (closest to intersection region), we decide on whether the Lane is an Ingress or Egress.
(236) Method 2: Based on Vehicle Movement Inside the Lane: Using the location of vehicle and its corresponding time-stamp, determine whether Vehicle is approaching Waypoint0, or leaving.
(237) Step 4: Determining Approach Set for Each of the Lanes: (See
(238) Step 5: Determining Connected Lanes: (See
(239) Step 6: Determining Movement States for Each Ingress Lane: For each of the Ingress lanes, based on the Connected-Egress lane's Maneuver code, determine the Movement state. Say, for example, the possible connection maneuvers are Left-Turn (LT), Straight (S), and then the Movement states are: LT movement, S movement.
(240) MAP Generation: Improvement to above described method in steps 1-6 with an additional Signal Data available from Traffic controller. (see
(241) The Idea in this method is to match Traffic controller's signal-phase data with vehicles' motion in each of the lanes and determine the signal phase for each of the Lane/Approach. Here is how it works: Continuously poll Traffic-controller for the Signal status information. When Traffic-controller is stating a particular phase number for the first time, during next short period of time, t.sub.2, e.g. 1-5 seconds, identify the lanes in which vehicles started moving from a halt. Of these lanes, identify the direction of travel of the vehicles in each ingress lane towards their egress lanes, and determine the Phase-number for that lane corresponding to that Movement state. For each of the Signal-phase mapped to the Ingress lane, count the number of vehicles using that phase to cross the Diamond region, N.sub.1. Eliminate the Outlier, e.g. 5% of the phases (if any), or the tail of the distribution, from the above list of phases for each of the Ingress lanes, resulting in a smaller number (N.sub.2).
(242) MAP Maintenance: Based on BSM messages(s) or equivalent vehicle message. (see
(243) MAP Maintenance: Improvement to above method with additional Signal Data available from Traffic Controller. (see
(244) MAP publishing, storing, and updating mechanisms: Broadcasting MAP information. (see
(245) Each of the RSE/Remote-Server would have 2 MAPS for each location, namely, Base-Map and Look-aside (Current-status) MAP.
(246) Case 1: No Base Map is Available (Initial Condition): For a Look-aside MAP, once the MAP has sufficient number of vehicle (say e.g. 100) traversals on each of its lanes, consider it for further calculations. Once the above limit is reached, execute a Map-matching of vehicles with Look-aside MAP, and determine the match percentage or ratio. Average the matching percentage for all the vehicles. If the Match-percentage is high (say e.g. above 99%), upgrade the Look-aside database at that instant to Base-MAP.
(247) Case 2: Base Map is Available (Updating Condition): Compare the Base Map with Look-aside MAP for following differences: Lateral distance shifts in the Waypoints of the lane: Ignore them if the shift is less than D.sub.s, e.g. 20 cm, or a threshold distance. In one embodiment, D.sub.s is defined e.g. based on lane width or average vehicle length or width, or based on D.sub.w. For example, D.sub.s is set equal to D.sub.w. In one embodiment, D.sub.s is adjusted based on historical data, or corrected by human expert periodically. Connection lane changes: Changes in possible maneuver codes of the lane and the connected lane lists. Change in Signal-Phase matching. In case the changes in the Base-Map and Look-aside Map are considerable (above a threshold), and base Map is failing to provide high-Map-matching results, while Look-aside MAP is able to provide high MAP-Matching results, consider upgrading Look-aside MAP in the following criteria: Manual override is detected for upgrading existing Look-aside MAP. The difference is seen consistently for more than e.g. a Day, or a specific time period T.sub.C, and there are sufficient numbers of vehicles, N.sub.V (say e.g. 1000), in each of the lanes, for proper statistics and analysis. Cherry pick these differences and update them in Base-Map.
Decreasing Computations and Increasing Confidence in MAP-Generations: (See
(248) Some minimal information, when available, could be manually fed to the system allowing the system to identify vehicle movements accurately and generate better results, in a shorter time period. For example: Approach Count, and Approach names Lane numbers in each Approach and Lane-widths Cross-Walks Traffic controller-information (to which system to poll and get results) Approximate intersection-Diamond region dimensions, or average/typical of those dimensions from other locations
Safety Consideration:
(249) Detecting an idle vehicle (or Breakdown vehicle or accident vehicle or a closed lane) and share the location of this vehicle with other vehicles make this concept of map extend, to have a safety attribute.
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(263) An embodiment of the invention is a method for creating, storing, and updating local dynamic map database with safety attribute, for a street or highway, said method comprising: a central computer receiving speed profiles from vehicles in said street or highway from an input device; an analyzer module or device determining vehicular density for said vehicles in said street or highway; an identifier module or device determining lane attributes for a lane in said street or highway; receiving traffic controller data for said street or highway; integrating said traffic controller data for said street or highway into map data; identifying temporary and permanent changes in said map data; updating said map data; and identifying an obstacle of mobility attribute in said map data.
(264) An embodiment of the invention is one of the following: identifying intersections for said street or highway. identifying an idle vehicle in said street or highway. identifying an accident in said street or highway. using a short range communication device. using an on-board device in a car. using a road side equipment. determining a status of said traffic controller data. determining a correlation with a status of said traffic controller data. storing said map data. generating a basic safety message. storing location, heading, and speed of a car. storing a time-stamp for a basic safety message. checking an accuracy of past history points. generating lanes for said street or highway. combining paths for said street or highway. using statistical analysis for paths. using weights for paths. detecting a lane change event. filtering outlier samples in statistical analysis.
(265) In one embodiment, the map can be generated in a central processor. In one embodiment, the map can be generated in distributed processors, and later merged together as one map. The advantage of the distributed-processors method is that if for any reason the communication or the processing is interrupted, the other processors can partially supply the data for the vehicles, for navigation and operation. In one embodiment, the processor is mobile itself, e.g., installed in a car, satellite, drone, balloon, or airplane. In one embodiment, the processor is stationary, at a fixed location. In one embodiment, the processor network manages the map, e.g., in a server farm.
(266) In one embodiment, each server covers one part of the city or area. In one embodiment, the geographical areas have overlaps for coverage. In one embodiment, there are redundancies between coverage of different units. In one embodiment, there is a correction based on the redundancies between coverage of different units, to find and filter out the erroneous data. In one embodiment, there is an averaging process based on the redundancies between coverage of different units, to average the data for more accurate results. In one embodiment, there is a weighted-averaging process based on the redundancies between coverage of different units, to weighted-average the data for more accurate results, with more weights for the more reliable units or sources, or higher weights for the results that are closer to the center of curve representing the distribution of values, i.e., eliminating or reducing the fringe results or erroneous data.
(267) In one embodiment, we have data distributed and sold to a third party subscribing to our service and data flow, as updates and feed, so that they can manage the traffic or control cars or analyze the data for marketing purposes or finding the trends. For example, from the traffic patterns, one can conclude that how many cars are going to the new mall or store and how long they stay at that mall in average, in terms of hours, and at what hours or which days, which will help the mall to plan for marketing and sales, e.g., to order merchandise in advance for specific people or specific time or season. In addition, from the traffic pattern, one can conclude that which areas or streets are most likely the source of cars to a specific mall or region, statistically, so that from the social or income data from a target neighborhood, one can find the social or income level of people likely going to a specific mall, and at what time during the day, as a probability distribution, so that the average, or median, or aggregate, or expected value, or standard deviation can be extracted or estimated for each parameter under study, e.g., income level or average age or gender, e.g., a stay-home or vacationing parent driving to mall during day time on weekdays (e.g., not working at an office or regular job or vacationing, so that have enough time during the day to go to mall during weekdays and non-holidays). Such estimates and statistics for patterns or behaviors for people are very valuable for marketing and sales people who want to predict and plan ahead. Thus, they buy these data and analyze and extract patterns from them for their specific purposes.
(268) Another purpose or usage for such data is for traffic planning or city expansion planning or metro rail planning for future, e.g., to remove congestion or reduce traffic around main roads or plan for gas stations or malls or office buildings or metro stations or train stations, or estimate the trend for population growth or movement or concentration throughout the years, by comparing such traffic data in time, e.g., to plan schools for future for a district. Aggregate and trend and direction results are very useful and valuable for people in charge or decision makers for all of the private and public sectors. For example, for heavily congested and concentrated intersections and roads, the real estate market and values may go up, due to demand for commercial space and office space. Or, the parking fee rate per hour or per day may go up, due to the demand or shortage for parking space, at least during the time that are the peak for traffic, from our data collected for various times and regions.
(269) Here, we describe some of our embodiments/examples, as components of our system:
(270) Map Generation: (See
(271) Generating Lanes: (See
(272) Determining Intersection and Lanes Splitting: (See
(273) Determining Lane Type (Ingress/Egress): (See
(274) Determining the Approach Set for Every Lane: (See
(275) Determining Connecting Lanes and Movement State for Ingress Lane: (See
(276) More in MAP Generation: (See
(277) Map Maintenance: (See
(278) More in Map Maintenance: (See
(279) Map Publishing, Storing, and Updating Mechanism: (See
(280) Safety Consideration: (See
Description of the Overall System
(281) Here, we describe the overall/general system for some of our embodiments above:
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(287) In one embodiment, we have the following technical components for the system: vehicle, roadway, communications, architecture, cybersecurity, safety reliability, human factors, and operations. In one embodiment, we have the following non-technical analysis for the system: public policy, market evolution, legal/liability, consumer acceptance, cost-benefit analysis, human factors, certification, and licensing.
(288) In one embodiment, we have the following requirements for AV (automated vehicles) system: Secure reliable connection to the command and control center Built-in fail-safe mechanisms Knowledge of its position and map database information (micro and macro maps) Communication with traffic lights/road side infrastructure Fast, reliable, and secure Situational awareness to completely understand its immediate surrounding environment Requires multiple sensors Algorithms to analyze information from sensors Algorithms to control the car, for drive-by-wire capability
(289) In one embodiment, we have the following primary technologies for our system: V2X communication: time-critical and reliable, secure, cheap, and dedicated wireless spectrum Car OBE (on-board equipment): sensor integration (vision, radar and ADAS (advanced driver assistance system)), positioning (accurate position, path, local map), wireless module (physical layer (PHY), Media Access Control (MAC), antenna), security (multi-layer architecture), processing and message engine, and algorithms for vehicle prediction and control
(290) In one embodiment, we have the following building blocks for AVs: Automation Platform i. Advanced Driver Assistance (ADAS) integration ii. Map Integration, Lane Control iii. Radio communications support iv. Vehicle Controller Unit to do actuation Base Station Ground positioning support to improve positioning accuracy V2I (vehicle to infrastructure) functionality, support for public/private spectrums Cloud connectivity to provide secure access to vehicles Command Control Center i. Integration with Infrastructure Providers
(291) Here are some of the modules, components, or objects used or monitored in our system: V2V (vehicle to vehicle), GPS (Global Positioning System), V2I (vehicle to infrastructure), HV (host vehicle), RV (remote vehicle, other vehicle, or 3.sup.rd party), and active and passive safety controls.
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(297) Here, we describe a method, as one embodiment: The first level of filtering is based on defining circle (geometry) of interest or any other geometrical shape (see also
(298) In one embodiment, for example, for calculating R, we have (see also
(299) R, as a function of host vehicle speed, F.sub.H, e.g.:
R=F.sub.H(V)=50+2V+(V.sup.2/8)
(300) Where V is the host vehicle speed in m/s.
(301) In one embodiment, F is a function of velocities, distances, and coordinates, both in absolute values and relative values, for host and other vehicles. In one embodiment, F is a function of polynomial of degree G, in host vehicle speed V. In the example above, we have: G=2.
(302) For example, for: 70 m≤R≤200 m
(303) That is, Maximum (R)=200 m, and
(304) Minimum (R)=70 m.
(305) The 70 meter will still be sufficient to do all the rear applications. These numbers are just examples for some specific applications.
(306) In one embodiment, the next step is to convert this R to delta Longitudinal and delta Latitude from the host vehicle coordinate. The objective here is to ignore all vehicles that are outside a radius. Here, we assumed circular filtering. Different types of geometric filtering can also be done: rectangle, ellipse, other irregular geometry, or any other regions or shapes. For circular filtering, given the current host vehicle (HV) coordinate (lat_HV, lon_HV), and given the desired filtering radius R, then the equivalent delta latitude (Delta_lat) and delta longitudinal (Delta_lon), from (lat_HV, lon_HV) for this radius R, are calculated as follows (see also
Delta_lat=(R/Radius_of_earth)=(R/6378137),
(307) e.g., based on Earth Equatorial radius of 6378137 m,
(308) and where R is in meter (m).
Delta_lon=arcsin(sin(Delta_lat)/cos(lat_HV))
(309) Therefore, in one embodiment, to apply the filtering algorithm for any node (Remote Vehicle (RV)), with the coordinate of (lat_RV, lon_RV), the following is executed (see also
(310) If Abs(lat_RV−lat_HV)>Delta_lat OR Abs(lon_RV−lon_HV)>Delta_lon
(311) Then: Ignore it (i.e., do not process it).
(312) Else: Process it.
(313) Wherein all “lat” and “lon” values are expressed in radian. The default value for R is 200 m, but it is configurable. For jam reduction and reduction of processing, in one embodiment, we want to ignore all the vehicles outside of the radius R.
(314) Now, in one embodiment, this value of R can be adaptively adjusted based on the statistical distribution of the nodes ranges (see also
(315) In one embodiment, the second level of filtering is based on the relative velocity between the host vehicle and the remote vehicle. For example, for all remote vehicles that have a value of the velocity component in host vehicle direction that is greater than the host vehicle velocity, and they are also at relatively high range distance from the host vehicle, then they constitute no immediate threat on the host vehicle (based on the probability) (see also
(316) In one embodiment, the third level of filtering is to adjust either the transmitted power and/or the received power threshold as a function of one of the following (as different embodiments) (see also
(317) a. Rate of change in the number of received nodes. As the number of nodes increases sharply, the host vehicle is approaching a congested traffic area, and therefore, the transmitted power can be decreased to reduce the communication range, and/or the received power threshold can be increased to reduce the receiving communication range (see also
(318) b. The map database can also be used very effectively: For example, if the number of connected road segments to the host vehicle road segment is high, and/or the total number of road segments is high within a defined area, then the transmitted power can be decreased, and/or the received power threshold can be increased (see also
(319) c. Based on the calculated R. For example, communication range R decreases/increases, as the transmission power increases/decreases (see also
(320) In one embodiment, the fourth level of filtering is just using the map database: For example, filter all the nodes (vehicles) that are on road segments that are not connected to the host vehicle road segment. An example for that is the main road and an overpass geometry. The main road and the overpass that passes over it are not connected, and thus, they do not make a V2V (vehicle to vehicle) possible traffic hazard. Map database can provide this information that these two road segments are not connected (see also
(321) The advantages of our methods are very clear over what the current state-of-the-art is. Our methods optimally use the available processing power and available bandwidth on processing the data of the desired nodes, which are relevant or important. They also help reducing the communication congestion problem.
(322) Tracking the Heading Angle of the Pedestrian
(323) Here, we describe embodiments for tracking the heading angle of the pedestrian system and method.
(324) The purpose of this approach is to track the heading angle of the pedestrian using existing sensors integrated in to a smart phone device or other mobile devices, e.g., wearables or smart watches.
(325) The system tries to use the following data when it is available:
(326) a. GPS—GPS position—GPS speed—GPS heading
(327) b. Compass heading
(328) c. Three rotation measurements (pitch, yaw, roll)
(329) d. Three acceleration measurements (down, longitudinal, lateral)
(330) In general, when a pedestrian is moving, it is an easy task to track its positions, and therefore, its heading. However, when the pedestrian is stopped, but changing his direction, tracking the heading, as his intended direction of travel, becomes a more difficult job. (See
(331) High level algorithm:
(332) Step 1:
(333) Calculate heading from GPS position:
ψ.sub.p=arcTan(ΔE/ΔN). (arc tan is the tan inverse function)
(334) See
(335) To see a significance difference in the position from one time epoch to a later one, this equation may apply at a lower data rate.
(336) Step 2:
(337) Based on the heading measurement, MPS, and/or the calculated one, ψ.sub.p, try to best-match the pedestrian walk with the intended intersection segment. This will be the initial high probability candidate (IC1). The second candidate is the one perpendicular to it (IC2). See
(338) Step 3:
(339) Determine if the pedestrian stopped. a. Detect a drop in speed. Watch the speed profile and look for a drop from a consistent profile. See
(340) At the end of Step 3, the pedestrian stop flag will either be set (value=1) or not changed at all (value=0).
(341) Step 4:
(342) If the stop flag is never set and the position of the pedestrian is within G=2 meter radius from the surveyed edge of the intersection, then IC1 is held as the intended driving path.
(343) Step 5:
(344) If StopFlag=1, then it is important to watch the behavior of the compass heading angle, ψ.sub.c, before the stop and during the stop. See
(345) We are trying to capture a turn maneuver by the pedestrian. Another way of doing it, if yaw rate signal is available, is to watch integration of the yaw rate for a window of T=1-2 sec. See
(346) Step 6:
(347) Offset the last ψ.sub.p and/or ψ.sub.GPS (before stop) by the value of Δψ.sub.c, or Δ.sub.ψ (call it ψ.sub.p corrected). (See above.)
(348) Step 7:
(349) Repeat Step 3 with ψ.sub.p corrected.
(350) Step 8:
(351) Once the pedestrian starts walking again, check how the ψ.sub.p-corrected is correlated with the new ψ.sub.p.
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(353) Here are some examples: A method for safe crossing for pedestrians in a street or highway, said method comprising: a central computer receiving global positioning system location data for a pedestrian during a first time period from a remote location; said central computer calculating an angle for heading and a vector for direction of said pedestrian, using said global positioning system location data for said pedestrian during said first time period; said central computer predicting a first choice candidate for intended intersection segment for said pedestrian to cross, based on said angle for heading and said vector for said direction of said pedestrian; said central computer predicting a second choice candidate for intended intersection segment for said pedestrian to cross, based on said angle for heading and said vector for said direction of said pedestrian; wherein said first choice candidate for intended intersection segment for said pedestrian to cross is perpendicular to said second choice candidate for intended intersection segment for said pedestrian to cross; said central computer monitoring speed profile for said pedestrian.
(354) If said central computer detects a drop from consistent range of said speed profile for said pedestrian, then said central computer determining that said pedestrian is stopping; said central computer determining cluster of positions for said pedestrian at rest status; said central computer monitoring acceleration profile for said pedestrian in 3 different dimensions; if said central computer detects a large negative drop from consistent range of said acceleration profile for said pedestrian, then said central computer determining that said pedestrian is stopping; said central computer receiving a flag value for rest status; said central computer receiving a radius value threshold distance; if said flag value for rest status is not true, and if distance between location of said pedestrian to an edge of an intersection for a street or highway is less than said radius value threshold distance, then said central computer selecting said first choice candidate for intended intersection segment for said pedestrian to cross.
(355) If said flag value for rest status is true, then said central computer evaluating behavior of said angle for heading for said direction of said pedestrian, before and during a stop event; a computation module integrating yaw rate for said pedestrian, for a second time period, to get an integrated yaw rate; said central computer receiving said integrated yaw rate from said computation module; said central computer offsetting said angle for heading for said direction of said pedestrian by said integrated yaw rate, to get a corrected angle for heading for said direction of said pedestrian; said central computer determining if said pedestrian is stopping, using said corrected angle for heading for said direction of said pedestrian: if said central computer detects that said pedestrian is walking, said central computer evaluating how said corrected angle for heading for said direction of said pedestrian correlates with a recent value of said angle for heading for said direction of said pedestrian.
(356) Other features are:
(357) monitoring multiple people.
(358) monitoring multiple cars.
(359) monitoring multiple intersections.
(360) warning multiple people.
(361) warning multiple cars.
(362) monitoring multiple global positioning values.
(363) monitoring multiple global positioning devices.
(364) communicating with multiple satellites.
(365) communicating with multiple telephone companies.
(366) communicating with multiple service providers.
(367) connecting cars with pedestrians.
(368) communicating with cars.
(369) communicating with pedestrians.
(370) communicating with cloud.
(371) communicating with server farms.
(372) communicating with police.
(373) alarming police.
(374) scanning intersections with more than 4 outlets or roads.
(375) correcting position data by local devices positioned at intersections, based on interactions with cell phones of pedestrians nearby, to register and record the position, and then later, compare those with other data, e.g., by satellite or GPS or maps.
(376) Here are other embodiments:
(377) A method for positioning based on geofencing framework for a road vehicle navigation system for a vehicle, said method comprising: a central computer receiving vehicle states for said vehicle; said central computer receiving yaw rate bias; said central computer removing said yaw rate bias; a processor determining whether reference road exists; in case said reference road exists, said processor determining whether said reference road is valid; in case said reference road is valid, said processor determining whether a lane change is detected for said vehicle; in case said lane change is detected for said vehicle, performing retrospective integrations of speed and yaw rate for said vehicle; said processor determining whether a yaw rate error is small; in case said yaw rate error is small, forcing said vehicle's heading angle to road heading angle; said processor updating said vehicle states; said processor evaluating geofencing conditions; said processor determining whether said geofencing conditions are met; in case said geofencing conditions are met, applying geofencing for said vehicle; updating said vehicle's position data; and outputting said vehicle's position data to upper layer of said road vehicle navigation system for said vehicle.
(378) Here are other embodiments: said road vehicle navigation system works with or communicates with a global navigation satellite system. said vehicle is interior to said reference road. distance to a next intersection is greater than a first threshold. said vehicle's speed is greater than a second threshold. said method comprises: timely geofencing. said method comprises: predicted geofencing. said method comprises: determining incorrect position. said method comprises: determining correct position. said method comprises: determining lateral error. said method comprises: determining reference path. said method comprises: determining longitudinal error. said method comprises: determining predicted path. said method comprises: determining average value. said method comprises: determining sensor temperature. said method comprises: determining vibration or noise. said method comprises: applying security layer for said road vehicle navigation system for said vehicle. said method comprises: applying application layer for said road vehicle navigation system for said vehicle. said method comprises: applying network layer for said road vehicle navigation system for said vehicle. said method comprises: applying physical layer for said road vehicle navigation system for said vehicle.
(379) Here are some examples:
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(384) In this disclosure, any computing device, such as processor, microprocessor(s), computer, PC, pad, laptop, server, server farm, multi-cores, telephone, mobile device, smart glass, smart phone, computing system, tablet, or PDA can be used.
(385) The communication can be done by or using sound, laser, optical, magnetic, electromagnetic, wireless, wired, antenna, pulsed, encrypted, encoded, or combination of the above. The vehicles can be car, sedan, truck, bus, pickup truck, SUV, tractor, agricultural machinery, entertainment vehicles, motorcycle, bike, bicycle, hybrid, or the like. The roads can be one-lane county road, divided highway, boulevard, multi-lane road, one-way road, two-way road, or city street. Any variations of the above teachings are also intended to be covered by this patent application.