TRAVEL ROUTE GENERATING METHOD FOR UNMANNED VEHICLE

• US 20100076640A1
• Filed: 09/21/2009
• Published: 03/25/2010
• Est. Priority Date: 09/22/2008
• Status: Active Grant

• Current Assignee: Komatsu Ltd., Yokohama National University
• Original Assignee: Komatsu Ltd., Yokohama National University
• Inventors: Noda, Tetsuya, Ozaki, Tomonori, MAEKAWA, Takashi, Tamura, Shigefumi
• Granted Patent: US 8,386,110 B2
• Time in Patent Office: Days
• US Class Current: 701/26
• CPC Class Codes: G05D 1/0217 in accordance with energy consumption, time reduction or distance reduction criteria

Abstract

A travel route generating method for an unmanned vehicle, which includes a condition input step of inputting a vehicle constraint condition including a vehicle width and a minimum turning radius of the unmanned vehicle, and a geometrical constraint condition including a travel route generation range in which the unmanned vehicle is to travel, an obstacle to avoid, and a position and a direction of an entrance point and an exit point; and a travel route generating step of generating a travel route such that the vehicle constraint condition and the geometrical constraint condition are satisfied, and such that a function value of a cost function having at least a magnitude of a curve and/or a rate of change in the curve as a cost element is minimized.

Claims

1. A travel route generating method for an unmanned vehicle comprising:

a condition input step of inputting a vehicle constraint condition including a vehicle width and a minimum turning radius of the unmanned vehicle, and a geometrical constraint condition including a travel route generation range in which the unmanned vehicle is to travel, an obstacle to avoid, and positions and directions of an entrance point and an exit point; and

a travel route generating step of generating a travel route such that the vehicle constraint condition and the geometrical constraint condition are satisfied, and such that a function value of a cost function having at least a magnitude of a curve and/or a rate of change in the curve as a cost element is minimized.

2. The travel route generating method for an unmanned vehicle as claimed in claim 1, wherein the magnitude of the curve is obtained on the basis of curvature of the travel route or a steering angle, and the rate of change in the curve is obtained on the basis of a rate of change in the curvature of the travel route or a steering operation amount.

3. The travel route generating method for an unmanned vehicle as claimed in claim 1, wherein the travel route generating step comprises a step of generating a travel route for the unmanned vehicle with a switchback point introduced therein, and the switchback point is determined so as to minimize the function value of the cost function.

4. The travel route generating method for an unmanned vehicle as claimed in claim 1, wherein the travel route generating step comprises:

a step of determining whether or not the generated travel route satisfies the vehicle constraint condition and/or the geometrical constraint condition, or whether or not the function value of the cost function is reduced by introduction of a switchback point; and

a step of, when it is determined that the generated travel route does not satisfy the vehicle constraint condition and/or the geometrical constraint condition, or it is determined that the function value of the cost function is reduced by introduction of the switchback point, generating a travel route for the unmanned vehicle with the switchback point introduced therein, and wherein

the switchback point is determined so as to minimize the function value of the cost function.

5. The travel route generating method for an unmanned vehicle as claimed in claim 1, wherein the travel route generating step comprises:

an interpolation point searching step of searching for an interpolation point of the travel route along which the unmanned vehicle is to travel; and

an interpolation step of interpolating the interpolation point in the route passing from the entrance point via the interpolation point to the exit point, and wherein

the search in the interpolation point searching step and/or the interpolation in the interpolation step are/is performed so as to minimize the function value of the cost function.

6. The travel route generating method for an unmanned vehicle as claimed in claim 5, wherein the interpolation in the interpolation step is performed by using a B-spline curve.