Method for operating an autonomous industrial truck

• US 9,145,286 B2
• Filed: 03/14/2011
• Issued: 09/29/2015
• Est. Priority Date: 03/25/2010
• Status: Active Grant

• Current Assignee: KUKA Laboratories GmbH (Midea Group Co., Ltd)
• Original Assignee: KUKA Roboter GmbH (Midea Group Co., Ltd)
• Inventors: Pfaff, Patrick, Sprunk, Christoph
• Primary Examiner(s): Black, Thomas G
• Assistant Examiner(s): Louie, Wae
• Application Number:
  US13/636,210
• Publication Number:
  US 20130060415A1
• Time in Patent Office: 1,660 Days
• Field of Search: 701/23, 701/50, 701/301, 701/498, 367/99, 367/96, 367/93, 367/108, 367/105, 342/71, 180/169, 180/168, 180/401, 180/167, 104/88, 340/904, 340/903, 208/408, 153/19, 172/4.5
• US Class Current: 1/1
• CPC Class Codes: B66F 17/003 for fork-lift trucks
• CPC Class Codes: B66F 9/063 Automatically guided
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 2013/93185 Controlling the brakes

Abstract

The invention relates to a method for operating an autonomous industrial truck (1), having the following method steps: determining, by means of a measuring apparatus (6) of the autonomous industrial truck (1), whether the industrial truck potentially hits at least one obstacle (7) on the basis of the present movement of said industrial truck (1), determining that point (14) of the industrial truck (1), and determining a maximum velocity for the present movement of the industrial truck (1) on the basis of the determined distance (d), with the result that the industrial truck reliably comes to a standstill in front of the obstacle (7) on the basis of possible braking of the industrial truck (1).

Claims

1. A method for operating an autonomous industrial truck, having the following method steps:

by means of a measuring apparatus of an autonomous industrial truck determining whether the industrial truck potentially collides with at least one obstacle on the basis of the present movement of said industrial truck, determining those points of the industrial truck at which the obstacle will potentially be hit,

determining the distance between the obstacle and the point of the industrial truck, and

determining a maximum velocity of the present movement of the industrial truck on the basis of the determined distance, with the result that the industrial truck reliably comes to a standstill in front of the obstacle on the basis of possible braking of the industrial truck;

wherein the movement of the industrial truck runs along a circular path or on a straight line,

wherein movement of the obstacle relative to the industrial truck is determined according to the equation

r₀²=(x−

x_m)²+(y−

y_m)²

whereby the industrial truck moves in a circular path with the radius and the instant center of rotation with the vehicle'"'"'s coordinates (x_m, y_m); and

the position of the obstacle is described with the vehicle'"'"'s coordinates (x₀, y₀), and r₀ is the distance of the obstacle to the instant center of rotation.

2. The method according to claim 1, in which the industrial truck takes the form of an holonomic industrial truck and/or the measurement apparatus takes the form of a laser scanner.

3. The method according to claim 1, in which the determination of the distance between the obstacle and the industrial truck is determined by the vehicle'"'"'s coordinates, and in particular the origin of the corresponding vehicle'"'"'s coordinate system lies in the center of the industrial truck.

4. The method according to claim 1, in which the contour of the industrial truck in particular is modeled by means of straight pieces and/or arc shaped pieces and the point lies on the modeled contour.

5. The method according to claim 4, in which the contour of the industrial truck is approximated as a rectangle.

6. The method according to claim 1, in which the coordinates (x_c, y_c) of the point are determined according to the equation

r₀²=(x_c−

x_m)²+(y_c−

y_m)².

7. The method according to claim 6, in which the contour of the industrial truck is modeled as a rectangle with straight pieces, whereby the front side of the industrial truck is modeled with a first straight piece, the back side of the industrial truck is modeled with a second straight piece, the left side of the industrial truck is modeled with a third straight piece, and the right side of the industrial truck is modeled with a fourth straight piece;

and

the coordinates of points are calculated as;

x_c=x_vor;

y_c=y_m±

√

{square root over (r₀²−

(x_vor−

x_m))},

if the point is set to the first straight piece,

x_c=x<sub>rü

ck</sub>, y_c=y_m±

√

{square root over (r₀²−

(x<sub>rü

ck</sub>−

x_m))},

if the point is set as the second straight piece,

x_c=x_links, y_c=y_m±

√

{square root over (r₀²−

(x_links−

x_m))},

if the point is set at the third straight piece,

x_c=x_rechts, y_c=y_m±

√

{square root over (r₀²−

(x_rechts−

x_m))},

if the point is set as the fourth straight piece.

8. The method according to claim 1, in which the industrial truck moves at an angle (α

) relative to its orientation along a straight line,

9. The method according to claim 8, by which the positions of the potential points are determined according to the following rule:

If v_x>

0 then the point potentially is found on the front side of the industrial truck corresponding to the first straight piece,

If v_x<

0 then the point potentially is found on the back side of the industrial truck corresponding to the second straight piece,

If v_y>

0 then the point potentially is found on the left side of the industrial truck corresponding to the third straight piece, and

If v_y<

0 then the point potentially is found on the right side of the industrial truck corresponding to the fourth straight piece.

10. The method according to claim 9, in which the distance between the point and the obstacle is determined according to the following rule:

If the point lies on the first straight piece, then the resulting coordinates for the point are

x_c=x_vor and

y_c=y₀+d·

v_y

and the distance is

11. The method according to claim 1, in which the contour of a vehicle edge of the industrial truck in its parameterized form relative to the vehicle'"'"'s coordinate system appears as follows:

12. An autonomous industrial truck, having a vehicle basic body, with wheels set on the vehicle basic body, at least one drive for driving at least one of the wheels, a measuring apparatus that is set up to determine whether on the basis of the current movement the industrial truck potentially collides with an obstacle, and a control apparatus connected with the measuring apparatus that is set up to control the drive and is set up to operate the industrial truck according to the method of claim 1.