Method for operating a planar motor

Patent metadata

Field	Value
Publication number	US-12510899-B2
Application number	US-202218077710-A
Country	US
Kind code	B2
Filing date	Dec 8, 2022
Priority date	Dec 9, 2021
Publication date	Dec 30, 2025
Grant date	Dec 30, 2025

Abstract

To reduce the risk of collisions of transport units or of a transport unit with an obstacle in the movement plane in a planar motor, at least two movement paths in the movement plane are expanded two-dimensionally around the respective movement path, at least in sections, to form a movement route in the movement plane. A conflict zone, in which there is a risk of collision, is determined by checking, whether there is any overlap between the at least two movement routes, in either individual movement route or between a movement route and an obstacle. The determined conflict zone is taken into account when controlling the movement of the transport units along the assigned movement path in order to avoid collisions between transport units moving on movement routes involved in the conflict zone or between a transport unit and the obstacle in the movement path.

First claim

The invention claimed is:

1 . A method for operating a planar motor having a movement plane in which a plurality of movement paths is prespecified and a plurality of transport units move along the plurality of movement paths, comprising:
forming at least two movement routes for at least two movement paths of the plurality of movement paths in the movement plane by two-dimensionally expanding the at least two movement paths, at least in sections, and prespecifying, at least in sections of the two-dimensionally expanded at least two movement routes, widths at each point of the two-dimensionally expanded at least two movement paths; determining at least one conflict zone in an overlap region at least one of:
between the at least two movement routes,
where at least one of the at least two movement routes overlaps with itself, or
where at least one of the at least two movement routes overlaps with an obstacle in the movement plane, in which the obstacle is defined by a location and geometry in the movement plane,

in which there is a risk of collision between transport units moving in a region of the at least one conflict zone in the at least one overlap region or a risk of collision between transport units and the obstacle in the movement plane in a region of the at least one conflict zone where the at least one of the at least two movement routes overlaps with the obstacle in the movement plane; and
based on the determined at least one conflict zone, controlling movement of the transport units along the at least two movement paths to avoid collisions between the transport units or between the transport units and the obstacle when the transport units move in the at least one conflict zone.

2 . The method according to claim 1 , wherein the width of at least one movement route in the movement plane is prespecified orthogonally to an assigned movement path.

3 . The method according to claim 1 , wherein the width of at least one movement route in the movement plane is prespecified asymmetrically to the movement path, at least in sections.

4 . The method according to claim 1 , further comprising determining a reference point on a transport unit moving on at least one of the at least two movement paths, and the at least one of the at least two movement paths is related to the reference point.

5 . The method according to claim 4 , further comprising determining vectors from the reference point to an outer contour of the transport unit in the movement plane at a position of the movement path on both sides of the transport unit as viewed in the direction of movement of the transport unit,
wherein the determined vectors are in each case projected onto a normal on the movement path at this position, and wherein a longest projection on each side of the transport unit are added to the width of the movement route at this position.

6 . The method according to claim 5 , wherein a prespecified geometric figure, which surrounds the transport unit in the movement plane, is used as the outer contour.

7 . The method according to claim 1 , wherein the controlling of the movement of the transport units along an assigned movement path, based on the determined conflict zone, comprises, for collision avoidance, replanning at least one of the movement routes involved in the conflict zone, at least in sections, in order to at least one of:
eliminate the conflict zone, reduce a size of the determined conflict zone, reduce a number of determined conflict zones, or reduce the number of movement routes involved in the conflict zone, or increase a distance between two conflict zones.

8 . The method according to claim 7 , wherein the replanning of the at least one of the movement routes includes at least one of replanning the assigned movement path, at least in sections, or changing a width of the at least one of the movement routes, at least in sections.

9 . The method according to claim 1 , wherein the controlling of the movement of the transport units along the at least two movement paths, based on the determined at least one conflict zone, comprises two-dimensional collision monitoring for collision avoidance in the at least one conflict zone,
wherein the two-dimensional collision monitoring checks whether there is a risk that a transport unit moving in a movement route including the at least one conflict zone will collide with another transport unit moving in another movement route including the at least conflict zone or with an obstacle in the movement plane.

10 . The method according to claim 1 , wherein the controlling of the movement of the transport units along the at least two movement paths, based on the determined at least one conflict zone, comprises, one-dimensional collision monitoring on a portion of the at least two movement paths outside of a region of the at least one conflict zone,
wherein the one-dimensional collision monitoring checks in a movement direction whether there is a risk of a collision between two transport units traveling one behind the other on the portion of the at least two movement paths outside of the region of the at least one conflict zone.

11 . The method according to claim 1 , wherein the controlling of the movement of the transport units along the at least two movement path, based on the determined at least one conflict zone, comprises checking, before a transport unit moving on a movement route including the at least one conflict zone enters the conflict zone, whether said transport unit can exit the conflict zone with the intended movement without colliding with another transport unit moving on a different movement route including the at least one conflict zone,
wherein, in a negative case, entry is denied.

12 . The method according to claim 1 , wherein the controlling of the movement of the transport units along the at least two movement path, based on the determined at least one, comprises assigning a priority to transport units, and a transport unit having the highest priority is granted entry into a conflict zone first.

Assignees

• B & R Ind Automation Gmbh
• Abb Schweiz Ag

Inventors

• Hauer Michael
• Flixeder Stefan

Classifications

• G05D1/693

  for avoiding collisions between vehicles · CPC title

• G05D1/622

  Obstacle avoidance (predicting or avoiding probable or impending collision of road vehicles B60W30/08) · CPC title

• H02K2201/18

  Machines moving with multiple degrees of freedom · CPC title

• H02K41/031

  of the permanent magnet type · CPC title

• B65G54/02 Primary

  electrostatic, electric, or magnetic · CPC title