Mapping systems and methods

• US 7,516,039 B2
• Filed: 10/18/2007
• Issued: 04/07/2009
• Est. Priority Date: 02/08/2006
• Status: Expired due to Fees

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: McKitterick, John B.
• Primary Examiner(s): TSAI, CAROL S W
• Application Number:
  US11/874,649
• Publication Number:
  US 20080040071A1
• Time in Patent Office: 537 Days
• Field of Search: 702/155, 701/207, 701/208, 701/209, 701/300, 340/990, 342/179, 348/169, 382/151, 382/152, 382/154, 180/116, 180/119, 180/167, 180/168, 180/169
• US Class Current: 702/155
• CPC Class Codes: G01C 21/188 for accumulated errors, e.g. by coupling inertial systems with absolute positioning systems
• CPC Class Codes: G01C 21/383 Indoor data
• CPC Class Codes: G01C 21/3848 Data obtained from both position sensors and additional sensors
• CPC Class Codes: G01C 7/06 of cavities, e.g. tunnels
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93
• CPC Class Codes: G05D 1/027 comprising intertial navigation means, e.g. azimuth detector inertial navigation G01C21/16; inertial navigation combined with non-inertial navigation instruments G01C21/165

Abstract

Improved systems and methods for mapping are provided. In one embodiment, a system for mapping is provided. The system comprises a rangefinder adapted to output range measurements; an inertial sensor adapted to capture inertial measurements including inertial forces acting on the rangefinder and the attitude of the rangefinder; and a processor coupled the rangefinder and the inertial sensor and adapted to receive a set of range measurements from the rangefinder and inertial measurements from the inertial sensor. The processor is adapted to produce a virtual room reconstruction based on the set of range measurements from the rangefinder and inertial measurements from inertial sensor.

Claims

1. A system for mapping, the system comprising:

a rangefinder adapted to output range measurements;

an inertial sensor adapted to capture inertial measurements including inertial forces acting on the rangefinder and the attitude of the rangefinder;

a processor coupled to the rangefinder and the inertial sensor, wherein the processor is adapted to receive a set of range measurements from the rangefinder and inertial measurements from the inertial sensor, is adapted to produce a virtual room reconstruction based on the set of range measurements from the range finder and inertial measurements from the inertial sensor, and wherein the processor is further adapted to produce a virtual room reconstruction of a physical room based on minimizing an error function

$\begin{array}{cc}E=\underset{i}{\sum <br><br>}<br><br>\frac{{\left(a_i-a_i^{\mathrm{\prime <br><br>}}\right)}^2}{{\mathrm{\sigma <br><br>}}_a^2}+\underset{j}{\sum <br><br>}<br><br>\frac{{\mathrm{\omega <br><br>}}_j-{\mathrm{\omega <br><br>}}_j^{\mathrm{\prime <br><br>}}}{{\mathrm{\sigma <br><br>}}_{\mathrm{\omega <br><br>}}^2}+\underset{k}{\sum <br><br>}<br><br>\frac{\left(d_k-d_k^{\mathrm{\prime <br><br>}}\right)}{{\mathrm{\sigma <br><br>}}_d^2}& \left(1\right)\end{array}$

wherein, a′

_i is a model approximation for acceleration a_i measured by the inertial sensor, ω

′

_j is a model approximation for the output ω

_j of a gyro-rate measured by the inertial sensor, and d′

_k is a model approximation for a distance to a wall d′

_k as measured by the rangefinder.

2. The system of claim 1, wherein the rangefinder comprises one or both of a laser rangefinder and a sonic rangefinder.

3. The system of claim 1, wherein the virtual room reconstruction includes one or more virtual walls representative of one or more physical walls of a physical room.

4. The system of claim 1, wherein the processor is adapted to produce a virtual room reconstruction incorporating one or more room features based on a set of range measurements from the rangefinder and inertial measurements from the inertial sensor.

5. A system for mapping, the system comprising:

a rangefinder adapted to output range measurements;

an inertial sensor adapted to capture inertial measurements including inertial forces acting on the rangefinder and the attitude of the rangefinder;

a processor coupled to the rangefinder and the inertial sensor, wherein the processor is adapted to receive a set of range measurements from the rangefinder and inertial measurements from the inertial sensor, is adapted to produce a virtual room reconstruction based on the set of range measurements from the range finder and inertial measurements from the inertial sensor, and is adapted to assemble a map based on establishing the relative position of two or more virtual room reconstructions; and

a display coupled to the processor and adapted to display the map.

6. The system of claim 5, wherein the room features include at least one of a door and a window.

7. The system of claim 5, wherein the processor is further adapted to assemble a map by minimizing at least one energy function based on physical constraints that arise from properties of buildings.

8. The system of claim 5, wherein the processor is further adapted to assemble a map based on reaching an equilibrium between a first force and a second force, wherein the first force is an attractive force between a first virtual wall of a first virtual room reconstruction and a second virtual wall of a second virtual room reconstruction, and the second force is a repelling force between the first virtual wall of the first virtual room reconstruction and the second virtual wall of the second virtual room reconstruction.

9. The system of claim 5, further comprising:

a communications interface coupled to the processor and adapted to establish a communications link with a second processor.

10. The system of claim 9, wherein the processor is further adapted to produce a virtual room reconstruction based one or more of range measurements, inertial measurements and virtual room reconstruction information received over the communications link.

11. The system of claim 9, wherein the second processor is adapted to assemble a map based on one or more of range measurements, inertial measurements and virtual room reconstruction information received over the communications link.

12. The system of claim 9, further comprising:

an image sensor coupled to the processor and adapted to capture image data, the processor further adapted to communicate the image data to the second processor via the communications link.

13. The system of claim 5, wherein the rangefinder comprises one or both of a laser rangefinder and a sonic rangefinder.

14. The system of claim 5, wherein the virtual room reconstruction includes one or more virtual walls representative of one or more physical walls of a physical room.

15. The system of claim 5, wherein the processor is adapted to produce a virtual room reconstruction incorporating one or more room features based on a set of range measurements from the rangefinder and inertial measurements from the inertial sensor.

16. A system for mapping, the system comprising:

a rangefinder adapted to output range measurements;

an inertial sensor adapted to capture inertial measurements including inertial forces acting on the rangefinder and the attitude of the rangefinder;

a processor coupled to the rangefinder and the inertial sensor, wherein the processor is adapted to receive a set of range measurements from the rangefinder and inertial measurements from the inertial sensor, is adapted to produce a virtual room reconstruction based on the set of range measurements from the range finder and inertial measurements from the inertial sensor;

a first communications interface coupled to the processor;

a second communications interface coupled to the rangefinder and the inertial sensor; and

wherein the first communications interface and the second communications interface are adapted to communicate range measurements from the rangefinder and inertial measurements from the inertial sensor to the processor via a communications link.

17. The system of claim 16, wherein the rangefinder comprises one or both of a laser rangefinder and a sonic rangefinder.

18. The system of claim 16, wherein the virtual room reconstruction includes one or more virtual walls representative of one or more physical walls of a physical room.

19. The system of claim 16, wherein the processor is adapted to produce a virtual room reconstruction incorporating one or more room features based on a set of range measurements from the rangefinder and inertial measurements from the inertial sensor.

20. The system of claim 16, wherein the processor is further adapted to assemble a map based on reaching an equilibrium between a first force and a second force, wherein the first force is an attractive force between a first virtual wall of a first virtual room reconstruction and a second virtual wall of a second virtual room reconstruction, and the second force is a repelling force between the first virtual wall of the first virtual room reconstruction and the second virtual wall of the second virtual room reconstruction.