Apparatus and method for smooth cornering in a motion control system
AssigneeSiemens Energy & Automation, Inc.
InventorStephen J. Yutkowitz
Life of this patent
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Abstract
A method and apparatus for controlling motion through consecutive linear spans that define a corner in a desired motion path, such as a motion path in a machine tool system for example, is disclosed. In one embodiment, a plurality of data points that define a desired motion path is provided, and the plurality of data points define a plurality of consecutive spans. It is determined whether two consecutive linear spans define a corner having an angle within a predetermined range, and if so, a non-linear path is determined which connects to the two consecutive linear spans with continuity in curvature. An actuator is then controlled according to the non-linear path.
Claims13
A method for controlling motion through consecutive linear spans which define a corner in a desired motion path, the method comprising:
- providing a plurality of data points which define a desired motion path, the plurality of data points defining a plurality of consecutive spans;
- determining whether two consecutive linear spans define a corner having an angle within a predetermined range;
- if two consecutive linear spans define a corner having an angle within the predetermined range, determining a non-linear path which connects to the two consecutive linear spans with continuity in curvature, wherein the non-linear path comprises two fourth order polynomial functions;
- and
- controlling an actuator according to the non-linear path which is determined.
A method for traversing a corner in a controlled motion path, the method comprising:
- providing a desired motion path which includes a corner portion;
- determining a non-linear path for traversing the corner portion;
- calculating a maximum speed for the non-linear path;
- moving a movable member according to the non-linear path instead of the corner portion, wherein the movement is constrained by the maximum speed calculated;
- wherein calculating a maximum speed further comprises the steps of:
- calculating a maximum tangent vector for the non-linear path;
- calculating a maximum curvature vector for the non-linear path;
- and
- calculating a maximum change in curvature vector for the non-linear path;
- wherein the maximum speed determining step further comprises the steps of:
- calculating a first maximum speed using the maximum tangent vector to constrain the path maximum velocities;
- calculating a second maximum speed using the maximum curvature vector to constrain the path maximum accelerations;
- calculating a third maximum speed using the maximum change in curvature vector to constrain the path maximum jerks;
- and
- selecting the maximum speed from the minimum of the first, second, and third maximum speeds.
A method for traversing a corner in a controlled motion path, the method comprising:
- providing a desired motion path which includes a corner portion;
- determining a non-linear path for traversing the corner portion;
- calculating a maximum speed for the non-linear path;
- moving a movable member according to the non-linear path instead of the corner portion, wherein the movement is constrained by the maximum speed calculated;
- wherein calculating a maximum speed further comprising the steps of:
- calculating a maximum tangent vector for the non-linear path;
- calculating a maximum curvature vector for the non-linear path;
- calculating a maximum change in curvature vector for the non-linear path
- calculating a first maximum speed using the maximum tangent vector to constrain the path maximum velocities;
- calculating a second maximum speed using the maximum curvature vector to constrain the path maximum accelerations;
- calculating a third maximum speed using the maximum change in curvature vector to constrain the path maximum jerks;
- and
- selecting the maximum speed from the minimum of the first, second, and third maximum speeds.
Dependencies are inferred from the claim text.