Dynamically adapting to changes in control system topology

1. A method implemented by an actuator or sensor of adapting to changes in the control topology of a cooperative control system including a plurality of controllers, the method comprising:

selecting, by the actuator or sensor, one of the controllers as the master controller for one or more state variables of the actuator or sensor;

detecting, by the actuator or sensor, a change in the control topology of the cooperative control system; and

reselecting, by the actuator or sensor, a master controller for the one or more state variables responsive to the change in the control topology.

2. The method of claim 1 wherein detecting a change in the control topology comprises detecting an addition of a new controller.

3. The method of claim 2 wherein reselecting a master controller comprises:

comparing a priority level of the new controller with a priority level of the current master controller; and

selecting the new controller to be the master controller if the priority level of the new controller is higher than the priority level of the current master controller.

4. The method of claim 3 further comprising maintaining the current master control as master controller if the priority level of the new controller is not higher than the priority level of the current master controller.

5. The method of claim 1 wherein detecting a change in the control topology comprises detecting a loss of a current master controller.

6. The method of claim 5 wherein reselecting a master controller comprises selecting a remaining one of the controllers as a new master controller.

7. The method of claim 6 wherein selecting a remaining one of the controllers as a new master controller comprises:

comparing the relative priority levels of two or more of the remaining controllers; and

selecting one of the remaining controllers to be the master controller based on the comparison.

8. The method of claim 1 further comprising:

receiving a command from an originating controller other than the current master controller; and

redirecting the command to the master controller.

9. An actuator or sensor in a cooperative control system, the actuator or sensor comprising:

a communication interface for communicating over a network with a plurality of controllers; and

a control circuit for adapting to changes in the control topology of the cooperative control system, said control circuit being configured to:

select one of the controllers as a master controller for one or more state variables of the actuator or sensor;

detect a change in the control topology of the cooperative control system; and

reselect a master controller for the one or more state variables responsive to the change in the control topology.

10. The actuator or sensor of claim 9 wherein the control circuit is configured to detect an addition of a new controller.

11. The actuator or sensor of claim 10 wherein the control circuit is configured to reselect a master controller by:

comparing a priority level of the new controller with a priority level of the current master controller; and

selecting the new controller to be the master controller if the priority level of the new controller is higher than the priority level of the current master controller.

12. The actuator or sensor of claim 11 wherein the control circuit is further configured to maintain the current master control as master controller if the priority level of the new controller is not higher than the priority level of the current master controller.

13. The actuator or sensor of claim 9 wherein the control circuit is configured to detect a loss of a current master controller.

14. The actuator or sensor of claim 13 wherein the control circuit is configured to reselect a remaining one of the controllers as a new master controller.

15. The actuator or sensor of claim 14 wherein the control circuit is configured to reselect a remaining one of the controllers as a new master controller by being configured to:

compare the relative priority levels of two or more of the remaining controllers; and

select one of the remaining controllers to be the master controller based on the comparison.

16. The actuator or sensor of claim 9 wherein the control circuit is further configured to:

receive a command from an originating controller other than the current master controller; and

redirect the command to the master controller.