Systems and methods for synchronizing nodes of a robotic system
A robotic system is provided. The robotic system includes a publishing node including at least one first synchronization database that includes a plurality of attributes, each of the attributes including a tag identifying the attribute and data, a flag associated with each of the attributes, and a subscriber list. The system also includes a subscriber node including at least one second synchronization database. The publishing node is configured to set the flag associated with the attributes when the attributes are written in the at least one first synchronization database or when the data included in the attributes are modified and publish the flagged attributes to the subscriber node.
1. A system comprising:
a first node comprising one or more first processors and a first synchronization database; and
a second node comprising one or more second processors and a second synchronization database;
wherein:
the first synchronization database comprises:
a subscriber list of a plurality of first subscribers;
a plurality of first attributes, each individual attribute of the plurality of first attributes including data and a tag, the tag identifying the individual attribute; and
a plurality of first flags, each individual flag of the plurality of first flags being associated with a corresponding one of the plurality of first attributes and a corresponding one of the plurality of first subscribers;
the first node is configured to:
receive a first subscription message from the second node, the first subscription message identifying a second attribute of the plurality of first attributes;
in response to receiving the first subscription message, add the second node to the subscriber list if the second node is not already in the subscriber list and set the individual flag of the plurality of first flags associated with both the second node and the second attribute;
on a condition that the data included in a third attribute of the plurality of first attributes is modified and the third attribute is associated with the second node by a second flag of the plurality of first flags, set the second flag; and
for each individual flag in the plurality of first flags that is set and is associated with the second node, publish the associated one of the plurality of first attributes to the second node; and
the second node is configured to:
send the first subscription message; and
store each of the published plurality of first attributes in the second synchronization database.
2. The system of claim 1 , wherein the first node is further configured to transmit an advertising message that advertises the plurality of first attributes.
3. The system of claim 1 , wherein the first node is further configured to:
receive a discover message from the second node; and
transmit a discover response message to the second node in response to the discover message, the discover response message including a list of the plurality of first attributes.
4. The system of claim 1 , wherein the first node is further configured to aggregate modifications to the plurality of first attributes until a synchronization reply signal is received from the second node.
5. The system of claim 1 , wherein the first node is further configured to delay publishing of attributes to the second node until a ready signal is received from the second node.
6. The system of claim 1 , wherein the first node and the second node are further configured to exchange heartbeat signals.
7. The system of claim 1 , wherein:
the first node is a first device or component in a robotic system; and
the second node is a second device or component in the robotic system.
8. The system of claim 7 , wherein:
the first node is a unit controller, a dispatcher, a manipulator, a supervisor, a video subsystem, or a user interface of the robotic system; and
the second node is a unit controller, a dispatcher, a manipulator, a supervisor, a video subsystem, or a user interface of the robotic system.
9. The system of claim 7 , wherein the first node is a link in a kinematic chain, an actuator, a sensor, or a subgroup of the robotic system.
10. The system of claim 7 , wherein the second node is a link in a kinematic chain, an actuator, a sensor, or a subgroup of the robotic system.
11. A method for synchronizing data across nodes in a system, the method comprising:
maintaining, by a first node of the system, a subscriber list of a plurality of first subscribers;
maintaining, by the first node, a plurality of first attributes, each individual attribute of the plurality of first attributes including data and a tag, the tag identifying the individual attribute;
maintaining, by the first node, a plurality of first flags, each individual flag of the plurality of first flags being associated with a corresponding one of the plurality of first attributes and a corresponding one of the plurality of first subscribers;
sending, by a second node of the system, a first subscription message, the first subscription message identifying a second attribute of the plurality of first attributes;
receiving, by the first node, the first subscription message;
adding, by the first node and in response to receiving the first subscription message, the second node to the subscriber list if the second node is not already in the subscriber list;
setting, by the first node and in response to receiving the first subscription message, the individual flag of the plurality of first flags associated with both the second node and the second attribute;
setting, by the first node and on a condition that the data included in a third attribute of the plurality of first attributes is modified and the third attribute is associated with the second node by a second flag of the plurality of first flags, the second flag;
publishing, by the first node and for each individual flag in the plurality of first flags that is set and is associated with the second node, the associated one of the plurality of first attributes to the second node; and
storing, by the second node, each of the published plurality of first attributes.
12. The method of claim 11 , further comprising transmitting, by the first node, an advertising message that advertises the plurality of first attributes.
13. The method of claim 11 , further comprising:
receiving, by the first node, a discover message from the second node; and
transmitting, by the first node and in response to the discover message, a discover response message to the second node, the discover response message including a list of the plurality of first attributes.
14. The method of claim 11 , further comprising aggregating, by the first node, modifications to the plurality of first attributes until a synchronization reply signal is received from the second node.
15. The method of claim 11 , further comprising delaying publishing, by the first node, of attributes to the second node until a ready signal is received from the second node.
16. The method of claim 11 , further comprising exchanging, by the first node and the second node, heartbeat signals.
17. The method of claim 11 , wherein:
the first node is a first device or component in a robotic system; and
the second node is a second device or component in the robotic system.
18. The method of claim 17 , wherein:
the first node is a unit controller, a dispatcher, a manipulator, a supervisor, a video subsystem, or a user interface of the robotic system; and
the second node is a unit controller, a dispatcher, a manipulator, a supervisor, a video subsystem, or a user interface of the robotic system.
19. The method of claim 17 , wherein the first node is a link in a kinematic chain, an actuator, a sensor, or a subgroup of the robotic system.
20. The method of claim 17 , wherein the second node is a link in a kinematic chain, an actuator, a sensor, or a subgroup of the robotic system.