SYSTEM FOR SENSING ROAD AND TRAFFIC CONDITIONS

• US 20090192688A1
• Filed: 06/26/2008
• Published: 07/30/2009
• Est. Priority Date: 01/30/2008
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Ramjee, Ramachandran, Mohan, Prashanth, Padmanabhan, Venkata N.
• Granted Patent: US 8,423,255 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: G08G 1/0104 Measuring and analyzing of parameters relative to traffic conditions

Abstract

A traffic sensing system for collecting information on traffic conditions is provided. A traffic sensing system includes a traffic sensing server and a mobile traffic sensing device that sends traffic reports to the traffic sensing server. An MTS device may use an accelerometer integrated into a smart phone to detect potholes, to detect when the vehicle is braking, to detect whether the MTS device is being transported via a vehicle or a pedestrian, to detect horns sounding, and so on. The MTS device reports the various conditions to the traffic sensing server for accurate assessment of traffic conditions at stretches of road through which vehicles transporting MTS devices travel.

Claims

1. A traffic sensing system for collecting information on traffic conditions, the system comprising:

a traffic sensing server for receiving traffic reports from mobile traffic sensing devices and providing aggregate traffic reports from the received traffic reports; and

a plurality of mobile traffic sensing devices for sensing traffic-related information near the devices and sending traffic reports to the traffic sensing server, the mobile traffic sensing devices including an accelerometer and a cellular communication device, a component that determines the orientation of the accelerometer, a component that samples the accelerometer, and a component that derives traffic-related information from the accelerometer samples.

2. The traffic sensing system of claim 1 wherein the component the determines the orientation does so using gravitational and braking forces.

3. The traffic sensing system of claim 2 wherein the component that determines the orientation computes a pre-rotation angle, a tilt angle, and a post-rotation angle based on the gravitational and braking forces.

4. The traffic sensing system of claim 3 wherein the accelerometer is virtually re-oriented so that to a canonical direction of X is along the forward direction of a vehicle transporting a mobile traffic sensing device, Y is along the direction to the side of the vehicle, and Z is vertically down.

5. The traffic sensing system of claim 2 wherein the braking forces are generated as a result of movement of a vehicle transporting a mobile traffic sensing device.

6. The traffic sensing system of claim 1 wherein a mobile traffic sensing device includes a component that detects whether a vehicle that is transporting the device is currently braking.

7. The traffic sensing system of claim 6 wherein a mobile traffic sensing device detects whether the vehicle that is transporting the mobile traffic sensing device is braking based on changes in accelerometer reading.

8. The traffic sensing system of claim 1 wherein a mobile traffic sensing device includes a microphone for sampling ambient sound near the device and a component that detects whether a horn is sounding based on the sampling of the ambient sound.

9. The traffic sensing system of claim 8 wherein the component that detects whether a horn is sounding does so based on generating a frequency spectrum of the samples of ambient sound and detecting multiple peaks with one peak being within a characteristic frequency associated with a sounding horn.

10. The traffic sensing system of claim 1 wherein a mobile traffic sensing device includes a component that detects whether a vehicle transporting the device has encountered a pothole.

11. The traffic sensing system of claim 10 wherein the component that detects whether a vehicle has encountered a pothole does so by checking for a spike in accelerometer samples in a vertical direction when the vehicle is traveling faster than a slow speed threshold and by checking for a sustained dip in the accelerometer samples when the vehicle is traveling slower than the slow speed threshold.

12. The traffic sensing system of claim 1 wherein a mobile traffic sensing device includes a component that detects whether the device is being transported by a vehicle or a pedestrian.

13. The traffic sensing system of claim 12 wherein the component that detects whether the device is being transported by a vehicle or a pedestrian does so by determining whether braking is detected based on changes in accelerometer samples.

14. The traffic sensing system of claim 1 wherein a mobile traffic sensing device includes a component that determines location of the device based on signals received by the device from cellular transmitters and an intersection of convex hulls that represent transmission range of those cellular transmitters.

15. The traffic sensing system of claim 1 wherein a mobile traffic sensing device includes a microphone for sampling ambient sound near the device and a component that detects enclosure type of a vehicle transporting the device based on a level of the ambient sound.

16. The traffic sensing system of claim 15 wherein some mobile traffic sensing devices send traffic reports to other mobile traffic sensing devices via a local area wireless network and wherein the enclosure type is based in part on traffic reports received from other mobile traffic sensing devices.

17. The traffic sensing system of claim 1 wherein some mobile traffic sensing devices send traffic reports to other mobile traffic sensing devices via a personal-area wireless network and include a component that detects whether a device is currently being transported by a mass transit vehicle based on proximity to the other devices as indicated by the traffic reports.

18. The method of claim 1 wherein a mobile traffic sensing device includes a higher energy consumption device that is enabled only when an algorithm that uses data of a lower energy consumption device determines that data from the higher energy consumption device is needed.

19. A mobile traffic sensing device for collecting information on traffic conditions, the device comprising:

a cellular phone with a microphone;

a global positioning system device;

a personal-area wireless network interface;

an accelerometer; and

a component for generating and sending traffic reports that includes a component that orients the accelerometer, a component that samples the accelerometer, the global positioning system device, and the microphone, a component that inputs traffic reports via the personal-area wireless network interface from other traffic sensing devices, and a component that derives traffic-related information from the accelerometer, the global positioning device, and the microphone samples and the traffic reports input from other traffic sensing devices.

20. A traffic sensing system for collecting information on traffic conditions, the system comprising:

a traffic sensing server that receives traffic reports from mobile traffic sensing devices and provides aggregate traffic reports generated from the received traffic reports; and

a plurality of mobile traffic sensing devices that include;

a cellular phone;

a global positioning system device;

an accelerometer; and

a component that generates and sends traffic reports that includes a component that orients the accelerometer, a component that samples the accelerometer and the global positioning system device, and a component that derives traffic-related information from the accelerometer and the global positioning device samples.