Robotic surgical system and method for communicating synchronous and asynchronous information to and from nodes of a robotic arm

1. A robotic surgical system comprising:

a robotic arm comprising a plurality of nodes arranged in a ring network; and

a controller configured to communicate with the plurality of nodes using a message comprising a plurality of fix-sized packets, each node in the ring network associated with a packet at a specific position in the message relative to a sync token;

wherein during a first communication cycle, the controller is configured to send the message to the ring network, and each node in the ring network is configured to:

extract the associated packet at the specific position to determine whether the packet includes a command from the controller;

replace the packet at the specific position when the node has motor feedback for the controller in response to at least one earlier command; and

forward the message to the next node in the ring network;

and wherein after a last node in the ring network forwards the message to the controller, the controller is configured to:

determine whether there is motor feedback from the plurality of nodes in the ring network; and

prepare a new message for a second communication cycle in response to the motor feedback.

2. The robotic surgical system of claim 1 , wherein the command is a synchronous command associated with a requirement that the synchronous command be processed upon receipt or within a predetermined time.

3. The robotic surgical system of claim 2 , wherein the synchronous command includes a motor command.

4. The robotic surgical system of claim 3 , wherein the motor command includes a specified torque or a specified position.

5. The robotic surgical system of claim 1 , wherein the command is an asynchronous command not associated with any temporal requirement for processing the asynchronous command.

6. The robotic surgical system of claim 5 , wherein the asynchronous command includes a request for information from the node.

7. The robotic surgical system of claim 6 , wherein the request for information from the node requests identification of a surgical tool, calibration information for the surgical tool or at least one kinematic parameter of the surgical tool.

8. The robotic surgical system of claim 6 , wherein the request for information from the node requests a measurement of temperature or a voltage of the node.

9. The robotic surgical system of claim 1 , wherein the controller is configured to generate, during communication cycle N between the controller and the plurality of nodes, a synchronous command based on a response received by the controller in communication cycle N-1 to a synchronous command sent by the controller in communication cycle N-2.

10. A method for sending a command to nodes of a robotic arm arranged in a ring network, the method comprising:

during a first communication cycle, and in response to a message sent to the ring network, extracting an associated packet at a specific position in the message relative to a sync token to determine whether the packet includes a command;

replacing the packet at the specific position when the node has motor feedback in response to at least one earlier command; and

forwarding the message to a next node in the ring network.

11. The method of claim 10 , and wherein after a last node in the ring network forwards the message to a controller, the controller is configured to:

determine whether there is one or more updates from the plurality of nodes in the ring network; and

prepare a new message for a next communication cycle.

12. The method of claim 10 , wherein the command is a synchronous command associated with a temporal requirement that the synchronous command be processed upon receipt or within a predetermined time.

13. The method of claim 12 , wherein the synchronous command includes motor command specifies a torque or a position.

14. The method of claim 10 , wherein the command is an asynchronous command not associated with any temporal requirement for processing the asynchronous command.

15. A robotic surgical system comprising:

a robotic arm comprising a plurality of nodes arranged in a ring network;

a controller configured to communicate with the plurality of nodes using a message comprising a plurality of fix-sized packets, each node in the ring network associated with a packet at a specific position in the message relative to a sync token, wherein at least one node in the ring network comprises:

means for extracting the associated packet at the specific position to determine whether the packet includes a command from the controller;

means for replacing the packet at the specific position when the node has motor feedback for the controller in response to at least one earlier command;

means for forwarding the message to the next node in the ring network;

wherein the controller comprises:

means for determining whether there is motor feedback from the plurality of nodes in the ring network; and

means for preparing a new message for a next communication cycle in response to the motor feedback.

16. The robotic surgical system of claim 15 , wherein the command is a synchronous command associated with a temporal requirement that the synchronous command be processed upon receipt or within a predetermined time.

17. The robotic surgical system of claim 15 , wherein the command is an asynchronous command including a request for information from the node for identification of a surgical tool, calibration information for the surgical tool, at least one kinematic parameter of the surgical tool, or a measurement at the node.