Time synchronization scheme between different computation nodes in autonomous driving system

A non-transitory machine-readable medium having instructions stored therein, which when executed by a processor, cause the processor to perform operations, the operations comprising:

• calibrating timing of a first computing node of an autonomous vehicle host system based on an external time source;
• transmitting, from the first computing node to a second computing node of the autonomous vehicle host system, a first timing message via a first communication channel between the first computing node and the second computing node;
• calibrating timing of the second computing node based on the first timing message to synchronize timing of the first computing node and of the second computing node, wherein the first computing node and the second computing node are configured to perform different autonomous driving operations of an autonomous driving vehicle (ADV) in a collaborated manner;
• transmitting, from the second computing node to a fourth computing node of the autonomous vehicle host system, a third timing message via a third communication channel between the second computing node and the fourth computing node;
• and
• calibrating timing of the fourth computing node based on the third timing message to synchronize timing of the second computing node and of the fourth computing node, and wherein the first, second, and fourth computing nodes are connected with a chain topology.

A data processing system, comprising:

• a processor;
• and
• a memory coupled to the processor to store instructions, which when executed by the processor, cause the processor to perform operations, the operations including
• calibrating timing of a first computing node of an autonomous vehicle host system based on an external time source,
• transmitting, from the first computing node to a second computing node of the autonomous vehicle host system, a first timing message via a first communication channel between the first computing node and the second computing node,
• calibrating timing of the second computing node based on the first timing message to synchronize timing of the first computing node and of the second computing node, wherein the first computing node and the second computing node are configured to perform different autonomous driving operations of an autonomous driving vehicle (ADV) in a collaborated manner,
• transmitting, from the second computing node to a fourth computing node of the autonomous vehicle host system, a third timing message via a third communication channel between the second computing node and the fourth computing node, and
• calibrating timing of the fourth computing node based on the third timing message to synchronize timing of the second computing node and of the fourth computing node, and wherein the first, second, and fourth computing nodes are connected with a chain topology.