Vehicle-mounted multi-controller time synchronization method and system

Abstract

The invention discloses a vehicle-mounted multi-controller time synchronization method and device, and the method comprises the steps that: one controller in all to-be-synchronized controllers is configured as a master synchronization controller, he rest controllers are configured as slave synchronization controllers, the master synchronization controller carries out the external synchronization through a GNSS clock, the external synchronization time difference is calculated through the master synchronization controller, the master synchronization controller and each slave synchronization controller perform internal synchronization, the master controller generates an internal synchronization signal according to the internal time and sends the internal synchronization signal and the external synchronization information to each slave synchronization controller, and each slave synchronization controller calculates an internal synchronization time difference after receiving the internal synchronization signal, and each slave synchronization controller realizes external synchronization with the GNSS clock according to the internal synchronization time difference and the received external synchronization information. The method has the advantages of being simple in implementation method, low in cost, high in synchronization precision, capable of preventing local time hopping during control time synchronization and the like.

Description

technical field [0001] The invention relates to the technical field of time synchronization of vehicle-mounted equipment, in particular to a method and system for time synchronization of vehicle-mounted multi-controllers. Background technique [0002] In the vehicle system, it is usually necessary to configure a variety of different types of controllers, such as industrial computer, TX2, Xavier, FPGA, MCU, etc. The internal time of each type of controller is different, and in this type of distributed system, it is often necessary to Use a global time to determine the order of various events in the system, coordinate the transmission of various messages, etc., to control and monitor the state of the system. Therefore, it is necessary to unify the local time of each component in the system, that is, to perform clock synchronization. [0003] At present, the commonly used distributed high-precision time synchronization methods mainly include the following: [0004] 1. GNSS clo...

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Problems solved by technology

[0009] However, the NTP clock synchronization method has the following problems: First, NTP clock synchronization needs to set up an NTP server, which increases costs and wiring harnesses; second, NTP clock synchronization accuracy is low and is affected by the load of the LAN network; third, NTP clock synchronization will modify the local time, Synchronization will cause local time jumps or time period changes

[0012] However, the PTP clock synchronization method will have the following problems: First, PTP clock synchronization needs to set up a PTP server, which increases costs and wiring harnesses; second, network nodes (switches) need to support the PTP protocol to achieve sub-microsecond precision time synchronization; third, PTP clock Synchronization will modify the local time, which will cause local time jumps or time cycle changes during synchronization

[0013] Moreover, some controllers in the vehicle system may not support NTP and PTP protocols. The above-mentioned NTP and PTP clock synchronization methods are not applicable to the clock synchronization of each controller in the vehicle system.

However, when applied to time synchronization among multiple controllers, the above-mentioned clock synchronization methods in the prior art need to connect each controller to a receiver or server respectively, which will make it impossible for all controllers to be synchronized when there is interference , not suitable for applications that require high time synchronization accuracy, such as an unmanned vehicle system that needs to achieve microsecond precision, and there may be local time jumps when the controller time is synchronized, the unmanned vehicle system is time-synchronized The requirements are relatively high, and it is necessary to achieve microsecond-level precision

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