Off-board navigation system for vehicles

• US 8,068,981 B2
• Filed: 05/29/2007
• Issued: 11/29/2011
• Est. Priority Date: 05/26/2006
• Status: Expired due to Fees

• Current Assignee: C.R.F. Societa Consortile Per Azioni
• Original Assignee: C.R.F. Societa Consortile Per Azioni
• Inventors: Lilli, Francesco, Liberto, Carlo
• Primary Examiner(s): Cheung; Mary
• Assistant Examiner(s): Shafi; Muhammad
• Application Number:
  US11/806,011
• Publication Number:
  US 20070299600A1
• Time in Patent Office: 1,645 Days
• Field of Search: 701117-119, 701/200, 701/201, 701/202, 701/204, 701207-218, 701220-226, 342/357.06, 342/357.13, 709/219, 709/242, 709/244, 340/995.13, 340/995.19, 348/211.3
• US Class Current: 701/209
• CPC Class Codes: G01C 21/3415 Dynamic re-routing, e.g. recalculating the route when the user deviates from calculated route or after detecting real-time traffic data or accidents
• CPC Class Codes: G08G 1/096811 where the route is computed offboard
• CPC Class Codes: G08G 1/096844 where the complete route is dynamically recomputed based on new data

Abstract

Described herein is an off-board navigation system for vehicles, comprising at least one operating center and at least one on-board navigation unit installed on board a vehicle, in which the operating center is provided with monitoring means configured for detecting events that modify the road conditions of stretches of road forming part of a road network, and processing means designed to determine, following upon detection of an event, whether said event has occurred on a stretch of road forming part of a route supplied to a user and, in this case, to request an alternative route and determine a point of no return (PNR) that is set along the route supplied to a user and beyond which the vehicle is no longer able to avoid the event and a point of influence (AR), in which the practicability of the route starts to be affected by the onset of the event and beyond which the user is still in time to request and receive an alternative route that will enable him to avoid the event in the case where the point of no return (PNR) has not yet been exceeded.

Claims

1. An off-board navigation system for vehicles, comprising:

at least one off board operating center; and

at least one on-board unit installed on board a vehicle and which communicates with said at least one off board operating center and can be used by a user for setting target destinations;

said at least one off board operating center comprising;

an off-board calculating unit, which receives a user request and is designed to calculate, in response, a route on the basis of the information regarding the position of said vehicle and on the basis of geographical data present in the off board operating center itself;

an off-board transceiver unit configured to transmit said route to said on-board unit; and

an off board monitoring system configured to monitor constantly the traffic and road conditions of a road network of a portion of territory and to detect traffic altering events that modify the road conditions of stretches of road forming part of said road network; and

an off-board processing system configured to determine, upon detection of an event that alters traffic conditions, whether said traffic altering event has occurred on a stretch of road forming part of said route supplied to said user and, in this case, to determine a point of no return (PNR) that is set along said route which corresponds to that point on the route beyond which any deviations from the route are no longer possible and beyond which said vehicle is no longer able to avoid said traffic altering event; and

a point of influence (AR) in which the amount of traffic congestion along said route starts to be affected by the onset of said traffic altering event and beyond which said user is still in time to request to and to receive from said operating center an alternative route designed to avoid said traffic altering event in the case where said point of no return (PNR) has not yet been exceeded, wherein the point of influence (AR) is determined on the basis of a distance (d) that said vehicle would cover in a time (t_est) of extinction of the traffic altering event if it were to cover said route in the opposite direction from the position of the traffic altering event and if it were to travel at a pre-set speed for covering said route; and

communicates such determination and associated data to the on-board unit.

2. The system according to claim 1, in which said off board processing system is moreover configured for:

estimating the current position of said vehicle;

determining on the basis of the estimated current position of said vehicle a temporal distance of said vehicle from said traffic altering event; and

verifying whether said temporal distance satisfies a pre-set relation with a pre-set threshold value.

3. The system according to claim 2, where said temporal distance satisfies said pre-set relation, said off board processing system is moreover configured for:

determining on the basis of the estimated current position of said vehicle a spatial distance of said vehicle from said traffic altering event; and

verifying whether said spatial distance satisfies a pre-set relation with a pre-set threshold value.

4. The system according to claim 3, where said spatial distance satisfies said pre-set relation, said off board processing system are moreover configured for:

asking the route-calculating unit to calculate on the basis of said estimated current position a route alternative to said route supplied to the user, which enables said user to avoid said traffic altering event.

5. The system according to claim 4, in which said off board processing system is moreover configured for calculating said point of influence (AR) and said point of no return (PNR) in the case where said off board route-calculating unit is able to calculate an alternative route.

6. The system according to claim 1, in which said off board processing system is configured to divide the route into discrete stretches and for determining said distance (d) on the basis of the traffic altering event on each stretch of road forming part of a portion of said route comprised between the estimated position of said vehicle and the point in which said traffic altering event has occurred.

7. The system according to claim 6, in which said off board processing system is configured for associating to each of the stretches of road comprised between the estimated position of the vehicle and the point in which the traffic altering event has occurred a weight that indicates the evolution of the traffic altering event on the stretch of road with respect to a pre-set threshold value.

8. The system according to claim 7, in which said off board processing system is configured for modifying said time (t_est) of extinction of the traffic altering event on the basis of the evolution of the traffic altering event on said stretches of road.

9. The system according to claim 8, in which said off board processing system is configured for reducing said time (t_est) of extinction of the traffic altering event in the case where at least half of said stretches of road presents a weight that indicates an improvement of the traffic altering event with respect to a pre-set threshold value.

10. The system according to claim 9, in which said off board processing system is configured for calculating said distance (d) on the basis of said reduced time (t_est) of extinction of the traffic altering event.

11. The system according to claim 8, in which said off board processing system is configured for prolonging said time (t_est) of extinction of the traffic altering event in the case where at least half of said stretches of road presents a weight that indicates a worsening of the traffic altering event with respect to a pre-set threshold value.

12. The system according to claim 11, in which said off board processing system is configured for calculating said distance (d) on the basis of said prolonged time (t_est) of extinction of the traffic altering event.

13. The system according to claim 1, in which in order to determine said point of no return (PNR), said off board processing system is configured for:

calculating a new route, assuming as starting a position of the vehicle a point that is located at a pre-set temporal distance from said traffic altering event; and

repeating said step of calculation, displacing said starting position of the vehicle until said new route presents a deviation with respect to said route supplied to said user.

14. The system according to claim 1, in which said off board monitoring system is configured for determining a weight that indicates the degree of seriousness of said traffic altering event and said processing system is configured for determining said point of influence (AR) and said point of no return (PNR) in the case where said weight associated to said traffic altering event will exceed a pre-set threshold value.

15. The system according to claim 14, in which said off board processing system is configured for sending to said on-board unit a message containing:

information that signals the presence of said traffic altering event on said route supplied to the user and said weight of said event;

information that signals the geo-referenced position of said traffic altering event;

information that signals the availability of said alternative route;

information that signals said point of influence (AR); and

information that signals said point of no return (PNR).

16. The system according to claim 15, in which said on-board unit is configured for evaluating whether said information received is of interest to the user.

17. The system according to claim 15, in which said on-board unit is configured for:

verifying on the basis of the current position of the vehicle whether the vehicle has already exceeded said point of influence (AR) and/or said point of no return (PNR) and, on the basis of said verification,

deciding whether to display a message for the user.

18. The system according to claim 17, in which said on-board unit is configured for displaying a message containing:

information that signals the presence of said event on said route supplied to the user and said weight of said event;

information that signals the geo-referenced position of said event;

information that signals the availability of said alternative route;

information that signals said point of influence (AR); and

information that signals said point of no return (PNR);

in the case where the vehicle has exceeded the point of influence (AR) but has not yet exceeded the point of no return (PNR).

19. The system according to claim 1, in which said on-board unit is configured for sending to the operating center a request for said alternative route.

20. The system according to claim 1, wherein the point of no return (PNR) is determined by repeatedly calculating the route supplied to a user, assuming, for each calculation, a vehicle starting position which is at a progressively increasing temporal distance from the traffic altering event, back along the route originally supplied to the user, until the calculated route presents a deviation from the original route.

21. An off-board navigation system for vehicles, comprising:

an off board navigating and operating system; and

an on-board unit installed on board a vehicle which is in communication with the off board operating system and which can be used by a user for setting target destinations;

said off board navigating and operating system including;

an off board calculating unit that receives a user request and, in response, calculates a route on the basis of the information regarding the position of said vehicle and on the basis of geographical data present in the off board operating system itself;

an off board transceiver unit which transmits route data to said on-board unit; and

an off board monitoring system which constantly monitors the traffic and road conditions of a road network of a portion of territory and to detect events that modify the road conditions of stretches of road forming part of said road network; and

an off board processing system which, following detection of a traffic altering event that changes traffic conditions,

determines whether said traffic altering event has occurred on a stretch of road forming part of said route supplied to said user and, in this case, then

determines a point of no return (PNR) that is set along said route and beyond which said vehicle is no longer able to avoid said traffic altering event; and

then

determines a point of influence (AR) in which the amount of traffic congestion along said route starts to be affected by the onset of said traffic altering event and beyond which said user is still in time to request to and to receive from said off board operating system an alternative route designed to avoid said traffic altering event in the case where said point of no return (PNR) has not yet been exceeded; and

communicates such determinations and associated data to the vehicle on-board unit.