METHOD FOR AUTOMATIC AVOIDANCE OF COLLISIONS BETWEEN A CRAFT AND FURTHER OBJECTS

• US 20110213513A1
• Filed: 09/19/2008
• Published: 09/01/2011
• Est. Priority Date: 09/20/2007
• Status: Active Grant

• Current Assignee: EADS Deutschland GmbH (Airbus SE)
• Original Assignee: Michael Naderhirn
• Inventors: Naderhirn, Michael
• Granted Patent: US 8,467,953 B2
• Time in Patent Office: Days
• US Class Current: 701/3
• CPC Class Codes: G05D 1/0202 specially adapted to aircraft
• CPC Class Codes: G08G 5/0086 for monitoring terrain radar or analogous systems specially adapted for terrain avoidance G01S13/935
• CPC Class Codes: G08G 5/045 Navigation or guidance aids, e.g. determination of anti-collision manoeuvers radar or analogous systems specially adapted for anti-collision between aircraft G01S13/933

Abstract

A method for controlling the motion of an object for the avoidance of collisions with obstacles includes: detecting of at least one non-stationary or stationary obstacle; defining a safety zone around the obstacle which moves together with the obstacle; detecting whether the obstacle, including its safety zone, is in a collision course with the object; calculating an avoidance trajectory, which by-passes the obstacle, such that the avoidance trajectory, at least approximately, is circularly shaped and that the circularly-shaped avoidance trajectory, or a straight line tangentially linked thereto, is tangent to the safety zone around the obstacle; and driving the object such that it follows, at least approximately, the calculated avoidance trajectory, whereby the calculated avoidance trajectory is tangentially linked to the previous trajectory.

Claims

1. A method for controlling the motion of an object for the avoidance of collisions with obstacles, the method comprising:

detecting at least one non-stationary or stationary obstacle;

defining a safety zone around the obstacle which moves together with the obstacle;

detecting whether the obstacle, including the safety zone, is in a collision course with the object;

calculating an avoidance trajectory, wherein the avoidance trajectory bypasses the obstacle, wherein the avoidance trajectory is at least approximately circularly shaped, and wherein the avoidance trajectory is tangent to the safety zone around the obstacle;

driving the object such that the object follows, at least approximately, the calculated avoidance trajectory, wherein the calculated avoidance trajectory is tangentially linked to a previous trajectory of the object.

2. The method of claim 1, further comprising:

driving the object such that the object follows a course which runs, at least for a given time, straight and tangentially to the previous trajectory as soon as the object reaches a point of tangency at the safety zone around the obstacle.

3. The method of claim 1, wherein, for the calculation of the avoidance trajectory, a velocity of the object is assumed to be constant.

4. The method of claim 1, wherein calculating the avoidance trajectory includes:

calculating a first curve by;

subtracting, starting from the position of the object at the beginning of the avoidance maneuver, wherein simultaneous motion of the obstacle is vectorially subtracted from a motion of the object along a circular arc;

calculating a second curve being equal to a margin of the safety zone around the obstacle at the time of the start of the avoidance maneuver; and

calculating a first point on the first curve that has a common tangent with a point on the second curve.

5. The method of claim 1, wherein calculating the avoidance trajectory includes:

[A] calculating a tangential contact with the safety zone around the obstacle assuming that the safety zone stands still exactly at a time of tangency with the avoidance trajectory;

[B] calculating a straight line which results from an extension of a vector which is formed by a subtraction of a velocity vector of the obstacle from a velocity vector of the movable object at the time of said assumed tangency;

[C] calculating at least one length by which the straight line calculated in step B intrudes, as a chord, into the safety zone around the obstacle which is assumed to stand still at the time of tangency with the trajectory;

[D] repeating the calculation of the step A, wherein the safety zone, which is assumed to stand still, is augmented as compared to the step A by a circumferential strip having a width that equals the at least one length as calculated in the step C.

6. The method of claim 1, wherein the safety zone around the obstacle is circular.

7. The method of claim 5, wherein the step D includes:

calculating the augmentation s of the radius of the safety zone by using the equation;

8. The method of claim 1, further comprising:

continuously surveying an area neighbouring the object using an on-board sensor system for detecting and locating potential obstacles.

9. The method of claim 1, further comprising:

calculating a projection of position and velocity of a detected obstacle into a plane of motion of the object;

calculating the avoidance trajectory using the projected velocity and position.

10. The method of claim 1, wherein the object is an air craft.

11. The method of claim 1, wherein the object is a submarine craft.

12. The method of claim 1, wherein the object is a space craft.

13. The method of claim 1, wherein the object is a ship.

14. The method of claim 1, wherein the object is a vehicle for driving on land.