Method for Preventing a Collision

• US 20080243387A1
• Filed: 09/14/2005
• Published: 10/02/2008
• Est. Priority Date: 09/15/2004
• Status: Active Grant

• Current Assignee: WFL Millturn Technologies GmbH & Co. KG (Helmut Rothenberger, PhD)
• Original Assignee: WFL Millturn Technologies GmbH & Co. KG (Helmut Rothenberger, PhD)
• Inventors: Schinerl, Christoph
• Granted Patent: US 8,577,591 B2
• Time in Patent Office: Days
• US Class Current: 701/301
• CPC Class Codes: B25J 9/1666 Avoiding collision or forbidden zones
• CPC Class Codes: B25J 9/1676 Avoiding collision or forbidden zones
• CPC Class Codes: G05B 19/4061 Avoiding collision or forbidden zones
• CPC Class Codes: G05B 2219/39098 Estimate stop, brake distance in predef time, then verify if in safe distance
• CPC Class Codes: G05B 2219/49141 Detect near collision and slow, stop, inhibit movement tool

Abstract

Disclosed is a method for preventing the collision of a part (1) movable along at least two shafts (x, y) relative to an obstacle (3), which shafts (x, y) each have a feeder drive, a minimum stopping distance (2) being determined repeatedly at predetermined time intervals (t1 to t2, etc.) from the relative location and speed data (x(t), y(t) or vx(t), vt(t)) of the moving part (1) as a function of the machine and part data required for this purpose and being taken as the basis for the collision calculation. In order to provide advantageous conditions for the method, it is proposed that the collision calculation be based on at least one component, from the components of the stopping distance (2) that are related to the individual shafts (x, y), which component is determined from the speed data (vx(t) or vy(t)) retrieved in the individual time intervals (t1 to t2, etc.) and varied by a maximum acceleration of the associated feeder drive at least during the retrieval time interval (t1 to t2, etc.).

Claims

1. A method for preventing the collision of a part movable along at least two shafts relative to an obstacle, which shafts each have a feeder drive, a minimum stopping distance being determined repeatedly at predetermined time intervals from the relative location and speed data of the moving part as a function of the machine and part data required for this purpose and being taken as the basis for the collision calculation, wherein the collision calculation is based on at least one component, from the components of the stopping distance (2) that are related to the individual shafts (x, y), which component is determined from the speed data (vx(t) or vy(t)) retrieved in the individual time intervals (t1 to t2, etc.) and varied by a maximum acceleration of the associated feeder drive at least during the retrieval time interval (t1 to t2, etc.).

2. The method for preventing a collision as claimed in claim 1, wherein the collision calculation for establishing a stopping region (5), formed by the possible stopping distances (2) of the part, for each shaft (x, y) is based on two components, related thereto, which two components are determined from the speed data (vx(t) or vy(t)) retrieved in the individual time intervals (t1 to t2, etc.) and increased or reduced by a maximum positive acceleration, for the one component, and maximum negative acceleration, for the other component, of the associated feeder drive at least during the retrieval time interval (t1 to t2, etc.).

3. The method for preventing a collision as claimed in claim 1, wherein for reducing the stopping region (5), at least the location data (x(t), y(t)) associated with the time interval (t2 to t3, etc.) following the retrieval time interval (t1 to t2, etc.) is used and additionally taken as the basis for the collision calculation.

4. The method for preventing a collision as claimed in claim 1, wherein the components of the stopping distance (2) whose values are additionally changed by safety factors are taken as the basis of the collision calculation.

5. The method for preventing a collision as claimed in claim 1, wherein the braking of the part (1) is initiated at the start of the time interval (t2 to t3, etc.) following the retrieval time interval (t1 to t2, etc.) if either a collision scenario is determined or the collision calculation has not been completed by the time interval (t2 to t3, etc.) following the retrieval time interval (t1 to t2, etc.).

6. The method for preventing a collision as claimed in claim 1, wherein after the initiation of braking, the repeated determination of the components of the stopping distance (2) is continued and is taken as the basis for the collision monitoring and wherein the brake is released with a freedom from collision determined thereby.