System and method for satisfying move constraints when performing a motion control sequence

• US 7,076,322 B2
• Filed: 03/29/2002
• Issued: 07/11/2006
• Est. Priority Date: 03/29/2002
• Status: Active Grant

• Current Assignee: National Instruments Corporation (Emerson Electric Company)
• Original Assignee: National Instruments Corporation (Emerson Electric Company)
• Inventors: Chandhoke, Sundeep
• Primary Examiner(s): Patel, Ramesh
• Application Number:
  US10/113,657
• Publication Number:
  US 20030193522A1
• Time in Patent Office: 1,565 Days
• Field of Search: 700/18, 700/23, 700/86, 700/87, 700/89, 700/17, 700/83, 700/61, 700/180, 700/181, 700/193, 700/194, 700/250, 700/253, 318/560, 318/561, 318/671
• US Class Current: 700/181
• CPC Class Codes: G05B 19/416 characterised by control of velocity, acceleration or deceleration G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/35473 Input limit values of speed, position, acceleration or force
• CPC Class Codes: G05B 2219/35488 Graphical user interface, labview
• CPC Class Codes: G05B 2219/43058 Limitation of acceleration, permissible, tolerable acceleration
• CPC Class Codes: G05B 2219/43065 Limitation of jerk
• CPC Class Codes: G05B 2219/43168 Motion profile planning for point to point control
• CPC Class Codes: G05B 2219/43203 Limitation of speed, permissible, allowable, maximum speed

Abstract

A system and method for specifying and satisfying move constraints when performing a motion control sequence. One or more motion control operations may be included in a sequence in response to user input. User input specifying one or more move constraints for a first motion control operation in the sequence may be received to a graphical user interface. When the motion control sequence is subsequently performed, the first motion control operation may be performed in such a way that the one or more specified move constraints are satisfied. The specified move constraints preferably do not cause the trajectory of the first motion control operation to be altered.

Claims

1. A computer-implemented method for creating a motion control sequence, the method comprising:

including one or more motion control operations in the sequence in response to user input;

displaying a first graphical user interface for configuring a first motion control operation of the one or more motion control operations, wherein the first graphical user interface is useable for specifying one or more move constraints, wherein each move constraint comprises a constraint on a kinematic variable;

receiving user input to the first graphical user interface specifying one or more move constraints for the first motion control operation, wherein the one or more specified move constraints indicate that the first motion control operation is to be performed in such a way that each move constraint is satisfied; and

storing information representing the sequence of motion control operations, wherein the stored information includes information representing the one or more specified move constraints for the first motion control operation.

2. The method of claim 1,

wherein the first motion control operation is operable to control a device to move along a first trajectory;

wherein the one or more specified move constraints indicate that the first motion control operation is to control the device to move along the first trajectory in such a way that each move constraint is satisfied.

3. The method of claim 2, further comprising:

receiving user input specifying the first trajectory for the first motion control operation;

wherein the stored information includes information representing the first trajectory.

4. The method of claim 1, wherein the one or more specified move constraints comprise one or more constraints on one or more of the following kinematic variables:

velocity;

acceleration;

deceleration; and

jerk.

5. The method of claim 1,

wherein the one or more specified move constraints includes a first move constraint;

wherein receiving user input specifying the first move constraint comprises receiving user input specifying a maximum bound for a first kinematic variable;

wherein the first move constraint indicates that the first motion control operation is to be performed in such a way that the first kinematic variable does not exceed the specified maximum bound.

6. The method of claim 1,

wherein the one or more specified move constraints includes a first move constraint;

wherein receiving user input specifying the first move constraint comprises receiving user input specifying a minimum bound for a first kinematic variable;

wherein the first move constraint indicates that the first motion control operation is to be performed in such a way that the first kinematic variable does not fall below the specified minimum bound.

7. The method of claim 1, further comprising:

executing the sequence of motion control operations;

wherein said executing the sequence of motion control operations comprises performing each motion control operation in the sequence to control motion of a device, wherein the first motion control operation is performed in such a way that the one or more specified move constraints are satisfied.

8. The method of claim 7,

wherein the first motion control operation has a first trajectory;

wherein said performing the first motion control operation comprises controlling the device to move along the first trajectory without violating the one or more specified move constraints.

9. The method of claim 7, wherein said executing the sequence of motion control operations comprises:

accessing the information representing the sequence of motion control operations to determine program instructions corresponding to motion control operations in the sequence; and

executing the program instructions.

10. The method of claim 7, further comprising:

creating program instructions executable to perform the sequence of motion control operations;

wherein said executing the sequence of motion control operations comprises executing the program instructions.

11. The method of claim 1, further comprising:

configuring a first trajectory for the first motion control operation in response to user input; and

applying an algorithm to the first trajectory to compute a plurality of points along the first trajectory;

wherein the plurality of points along the first trajectory enables the first motion control operation to be performed without violating the one or more specified move constraints.

12. The method of claim 11, further comprising:

performing the first motion control operation;

wherein said performing the first motion control operation comprises controlling a device to pass through the plurality of points along the first trajectory.

13. The method of claim 12,

wherein said controlling the device to pass through the plurality of points along the first trajectory comprises controlling the device to pass through the plurality of points along the first trajectory at fixed time steps;

wherein said applying the algorithm to the first trajectory to compute the plurality of points along the first trajectory comprises determining a spacing between the points that allows the first motion control operation to be performed without violating the one or more specified move constraints.

14. The method of claim 11, further comprising:

wherein the first trajectory is specified by a first plurality of points along the first trajectory;

wherein the first plurality of points defines points through which to move a device at fixed time step intervals when the first motion control operation is performed;

wherein the first plurality of points is spaced in a way that prevents the first motion control operation to be performed without violating the one or more specified move constraints;

wherein said applying an algorithm to the first trajectory comprises applying the algorithm to produce a second plurality of points along the first trajectory;

wherein the second plurality of points defines points through which to move a device at fixed time step intervals when the first motion control operation is performed;

wherein the second plurality of points is spaced in a way that enables the first motion control operation to be performed without violating the one or more specified move constraints.

15. The method of claim 14,

wherein the one or more specified move constraints include a move constraint specifying a maximum bound on a first kinematic variable;

wherein the first plurality of points includes a first subset of points along a first portion of the first trajectory;

wherein the points in the first subset of points are spaced in a way that causes the first kinematic variable to exceed the maximum bound when the first portion of the first trajectory is performed;

wherein the second plurality of points computed by the algorithm includes a second subset of points along the first portion of the first trajectory;

wherein the points in the second subset of points are spaced in a way that enables the first portion of the first trajectory to be performed without exceeding the maximum bound.

16. The method of claim 15,

wherein the second subset of points has a larger number of points than the first subset of points.

17. The method of claim 11,

wherein the one or more specified move constraints include a constraint on a first kinematic variable;

wherein the first trajectory is specified by a first plurality of points along the first trajectory, wherein said applying the algorithm to compute a plurality of points along the first trajectory comprises applying the algorithm to compute a second plurality of points along the first trajectory;

wherein said applying the algorithm comprises;

fitting a curve to the first plurality of points;

calculating a profile for the first kinematic variable;

mapping points to the curve to compute the second plurality of points, wherein said mapping utilizes the profile for the first kinematic variable to compute points spaced along the curve in a way that enables the first motion control operation to be performed while satisfying the constraint on the first kinematic variable.

18. The method of claim 1,

wherein the first motion control operation is operable to control movement of a device through two dimensions;

wherein the one or more specified move constraints indicate that movement of the device is to be controlled in such a way that each move constraint is satisfied.

19. The method of claim 1,

wherein the first motion control operation is operable to control movement of a device through three dimensions;

wherein the one or more specified move constraints indicate that movement of the device is to be controlled in such a way that each move constraint is satisfied.

20. The method of claim 1, further comprising:

displaying a time profile for a first kinematic variable;

wherein said receiving user input to the first graphical user interface specifying one or more move constraints comprises receiving user input specifying a constraint on the first kinematic variable;

wherein the method further comprises updating the displayed time profile for the first kinematic variable to reflect the specified constraint on the first kinematic variable.

21. The method of claim 20,

wherein said receiving user input to the first graphical user interface specifying the constraint on the first kinematic variable comprises receiving user input to the displayed time profile.

22. The method of claim 21,

wherein said receiving user input to the displayed time profile comprises receiving user input to change the time profile.

23. The method of claim 20,

wherein said receiving user input to the first graphical user interface specifying the constraint on the first kinematic variable comprises receiving text data to the graphical user interface.

24. The method of claim 1,

wherein said including the one or more motion control operations in the sequence in response to user input does not include receiving user input specifying programming language code to implement the sequence of motion control operations;

wherein said receiving user input to the first graphical user interface specifying one or more move constraints for the first motion control operation does not include receiving user input specifying programming language code to implement the one or more move constraints.

25. The method of claim 1,

wherein the motion control sequence is operable to control motion of a device.

26. The method of claim 1,

wherein the motion control sequence is operable to control a device to move an object.

27. The method of claim 1, further comprising:

receiving user input requesting to configure the first motion control operation;

wherein the first graphical user interface for configuring the first motion control operation is displayed in response to the request.

28. A computer-implemented method for creating a motion control sequence, the method comprising:

including one or more motion control operations in the sequence in response to user input;

displaying a first graphical user interface for configuring a first motion control operation of the one or more motion control operations;

receiving user input to the first graphical user interface to configure the first motion control operation, wherein said receiving user input to the first graphical user interface to configure the first motion control operation comprises receiving user input to the first graphical user interface specifying one or more move constraints for the first motion control operation, wherein said specifying the one or more move constraints comprises specifying a value for one or more of the following;

a maximum velocity;

a maximum acceleration;

a maximum deceleration; and

a maximum jerk;

wherein the one or more move constraints indicate that the first motion control operation is to be performed without exceeding the one or more specified values; and

storing information representing the sequence of motion control operations, wherein the stored information includes information representing the one or more move constraints for the first motion control operation.

29. A computer-implemented method for creating a motion control sequence, the method comprising:

including one or more motion control operations in the sequence in response to user input;

displaying a first graphical user interface for specifying one or more move constraints, wherein each move constraint comprises a constraint on a kinematic variable;

receiving user input to the first graphical user interface specifying one or more move constraints for the motion control sequence, wherein the one or more specified move constraints indicate that the motion control sequence is to be performed in such a way that each move constraint is satisfied; and

storing information representing the sequence of motion control operations, wherein the stored information includes information representing the one or more specified move constraints.

30. A computer-implemented method for performing a motion control operation, the method comprising:

receiving a first plurality of points defining a trajectory for the motion control operation;

receiving input specifying one or more move constraints for the motion control operation, wherein each move constraint comprises a constraint on a kinematic variable; and

computing a second plurality of points based on the first plurality of points and the one or more move constraints, wherein the second plurality of points comprises a plurality of points through which to move when performing the motion control operation, and wherein the second plurality of points enables the motion control operation to be performed in such a way that the one or more move constraints are satisfied.

31. The method of claim 30,

wherein the second plurality of points defines a trajectory that is consistent with the trajectory defined by the first plurality of points.

32. The method of claim 30,

wherein the second plurality of points defines a trajectory identical to the trajectory defined by the first plurality of points.

33. The method of claim 30,

wherein said computing the second plurality of points comprises computing the second plurality of points such that points are spaced apart from each other in such a way that the one or more move constraints are satisfied when passing through the points at fixed time-step intervals.

34. The method of claim 30, wherein the first plurality of points define an irregular trajectory.