Controller, multiple redundant control system and synchronous control method thereof

Abstract

The invention discloses a controller, a multi-redundancy control system and a synchronous control method thereof. The multi-redundancy control system at least comprises a first controller and a second controller, wherein the first controller and the second controller are connected through a fixed data transmission channel. After receiving synchronous information, the first controller records first clock time information of a clock of the first controller, analyzes the synchronous information, and obtains second clock time information of the second controller. Clock skew of the first controller and the second controller can be calculated through the first clock time information, the second clock time information and transmission time of the fixed data transmission channel, and the clocks of the controllers are regulated according to a regulating strategy of controllers with slowest clock time so as to enable the clocks of the controllers in the multi-redundancy control system to keep pace with the clock of the controller with the slowest clock time. The synchronous control method achieves uniformity of the clocks of all the controllers without changing an original system hardware circuit, structure is simple, and reliability is high.

Description

technical field [0001] The present application relates to the technical field of multiple redundancy control, in particular to a multiple redundancy system and a control method thereof. Background technique [0002] Multiple redundant control systems belong to the field of industrial process control security, which has high requirements on the reliability and security of multiple redundant control systems. For example, the triple redundant control system uses two out of three votes, and when a single controller fails, it can still output the correct result, ensuring the accuracy and safety of the system in a faulty state. [0003] Among them, the synchronization technology in the multiple redundant control system is the core part, and its reliability and safety are very important. The multiple controllers in the system achieve a relatively consistent state in terms of program execution status, cycle timing, and system time. In this way, multiple controllers in the system ca...

AI Technical Summary

Problems solved by technology

[0004] At present, the methods for improving the synchronization degree provided by multiple redundant control in the prior art mainly include two types. One is the hardware synchronization method, which unifies the cycle clocks of multiple controllers through the hardware voting circuit to achieve the synchronization of multiple controllers. Purpose, this method needs to use hardware circuits to complete the unification of periodic clocks, which increases the complexity of the hardware failure model. Moreover, the periodic clocks used for voting need to be interrupted, and the generated frequency has higher requirements on the frequency of the CPU of the system, which increases the complexity of the circuit

Second, the synchronization between multiple controllers is carried out through data communication. Specifically, after the initialization of the new power-on controller, first determine the controller that is currently online, and then select the one with the smaller device address to interact with it for synchronization information , this method also requires the time for the new power-on controller to send the request frame, the time for the online controller to receive the time, the time for the online controller to reply, and the time for the new power-on controller to receive the reply message, and calculate these four times to complete Deviation adjustment between multiple controllers, only newly powered controllers are designed synchronously, moreover, the reference point design of the system is flawed, when the reference controller is replaced, all controllers in the entire redundant control system The clock of the system may jump, which may cause inconsistencies in the time of the controllers in the system

Images