Scalable motion control system

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.

What is claimed is: 
     
         1 . A method of bringing an axis to a controlled stop comprising:
 determining occurrence of an uncommanded electrical power loss to a system including the axis;   setting a predetermined time period applying a mode of operation of the axis and applying a trajectory to the axis that brings the axis to a zero velocity within the predetermined time period where motion of the axis along the trajectory is coordinated with motion of another axis; and   removing power from the axis at an end of the predetermined time period.   
     
     
         2 . The method of  claim 1 , wherein the predetermined time period is determined by calculating a time remaining before power is lost to the axis. 
     
     
         3 . A method of verifying the integrity of data transmitted over a control system network comprising:
 storing operating parameters at a node on the control system network; and   verifying that commands received through the control system network do not cause operations of the node that exceed the operating parameters.   
     
     
         4 . The method of  claim 3 , comprising disabling the node if the commands cause operations of the node to exceed the operating parameters 
     
     
         5 . The method of  claim 4 , wherein the operating parameters include a maximum axis velocity. 
     
     
         6 . The method of  claim 3 , wherein the operating parameters include an axis velocity error. 
     
     
         7 . The method of  claim 3 , wherein the operating parameters include a time during which a maximum velocity may be exceeded. 
     
     
         8 . A method of verifying the integrity of a control system network comprising:
 issuing a periodic message; and   disabling one or more nodes of the control system network if the periodic message is not received within a time period.   
     
     
         9 . The method of  claim 8 , wherein the periodic message is a position velocity time message frame. 
     
     
         10 . The method of  claim 8 , wherein the periodic message is issued by a network controller and the one or more nodes are disabled if a first node of the one or more nodes does not receive the periodic message. 
     
     
         11 . The method of  claim 8 , wherein the periodic message is issued by the one or more nodes and the one or more nodes are disabled if a network controller does not receive the periodic message. 
     
     
         12 . The method of  claim 8 , comprising removing power from selected ones of the one or more nodes if the periodic message is not received within a time period. 
     
     
         13 . A method of maintaining integrity of a control system network comprising:
 assigning nodes of the network into zones such that motion in a first zone is isolated from motion in zones other than the first zone, where zone to zone integrity signals are shared between the zones; and   controlling the zones, based on the zone to zone integrity signals, so that a disruptive event disruptive of an operation of the first zone does not effect disruption of another operation of zones other than the first zone.   
     
     
         14 . The method of  claim 13 , comprising disabling the first zone and routing work designated for the first zone to a zone other than the first zone.