SCALABLE MOTION CONTROL SYSTEM

• US 20110118855A1
• Filed: 01/24/2011
• Published: 05/19/2011
• Est. Priority Date: 06/08/2005
• Status: Active Grant

• Current Assignee: Brooks Automation Ltd. (United Kingdom) (Azenta, Inc.)
• Original Assignee: Brooks Automation Incorporated (Azenta, Inc.)
• Inventors: Caveney, Robert, Beale, Stuart, Hofmeister, Christopher, Hosek, Martin, Coady, Matthew, Ives, Mark, Botev, Roumen, Moura, Jairo
• Granted Patent: US 9,020,617 B2
• Time in Patent Office: Days
• US Class Current: 700/29
• CPC Class Codes: G05B 19/4148 characterised by using several processors for different functions, distributed (real-time) systems G05B19/4141 takes precedence
• CPC Class Codes: G05B 19/4185 characterised by the network communication
• CPC Class Codes: G05B 2219/31207 Master sends global files to autonomous controllers, feedback of process status
• CPC Class Codes: G05B 2219/33277 Distributed system with host as leader, host with multiple of agents
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A control system includes a clustered architecture having a master controller, a central control section including one or more first remote controllers under direct control of the master controller, and a distributed control section including a cluster controller controlled by the master controller. The cluster controller controls the activities of one or more second remote controllers. Each of the first and second remote controllers are utilized to drive one or more axes.

Claims

1. A method of operating an axis of a control system comprising:

generating a trajectory for the axis in terms of a position, velocity, and acceleration for each point of a plurality of points on the trajectory; and

calculating an inverse dynamic model of the axis to determine a gain value and a feedforward term for each point.

2. The method of claim 1, comprising grouping the position, velocity, acceleration, gain value, and feedforward term for each point into a frame.

3. The method of claim 2, comprising interpolating between two consecutive frames to obtain an instantaneous position, instantaneous velocity, instantaneous feedforward term and instantaneous gain value utilized to control the axis.

4. A method of obtaining axis data at the time of an event, comprising:

buffering data at one or more axis nodes;

recording time information of a triggering event occurring at a triggering event node of the one or more axis nodes; and

processing the buffered data to determine a set of values at a time period indicated by the recorded time information.

5. The method of claim 4, comprising sending the recorded time information to the one or more axis nodes.

6. The method of claim 5, comprising processing the buffered data at the one or more axis nodes.

7. The method of claim 6, further comprising sending the set of values to a node controller operating to control the one or more axis nodes.

8. The method of claim 4, comprising sending the recorded time information to a node controller operating to control the one or more axis nodes.

9. The method of claim 8, comprising sending the buffered data to the node controller and processing the buffered data at the node controller.

10. The method of claim 4, comprising sending the recorded time information to the one or more axis nodes from the triggering event node.

11. The method of claim 4, wherein sending the recorded time information to the one or more axis nodes comprises sending the recorded time information to a node controller operating to control the one or more axis nodes and then to the one or more axis nodes from the node controller.

12. The method of claim 4, further comprising sending the set of values to a node controller operating to control the one or more axis nodes.

13. A method for controlling an axis of a control system comprising:

calculating an operating parameter value for an end effector of the axis;

generating a motion profile for an individual joint of the axis such that a motion profile for the end effector does not exceed the operating parameter value.

14. The method of claim 13, wherein the operating parameter value is a maximum velocity.

15. The method of claim 13, wherein the operating parameter value is a maximum torque.

16. A method for controlling an axis comprising:

calculating a velocity and a torque for a position of the axis;

predetermining a first maximum time period during which an axis velocity may exceed the calculated velocity;

predetermining a second maximum time period during which an axis torque may exceed the calculated torque;

disabling the axis if the first or second maximum time period is exceeded.

17. The method of claim 16, comprising disabling the axis if the calculated velocity exceeds a predetermined maximum velocity.

18. The method of claim 17, comprising disabling the axis if the calculated torque exceeds a predetermined maximum torque.

19. The method of claim 16, comprising disabling the axis upon failure to receive a periodic communication from the axis.

20. The method of claim 16, comprising disabling the axis upon failure to receive a periodic communication from an axis controller.

21. A method of bringing an axis to a controlled stop comprising:

determining if power has been lost to a system including the axis;

applying a trajectory to the axis that brings the axis to a zero velocity within a predetermined time period; and

removing power from the axis at the end of the predetermined time period.

22. The method of claim 21 wherein the predetermined time period is determined by calculating a time remaining before power is lost to the axis.