Engine Control Unit Serial Communication Noise Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Control devices that drive loads, such as ignition devices and fuel injectors, experience delays and increased processor load due to the transmission of the same data twice in serial communication, leading to reduced engine response and noise issues.
Innovation Solution
A control device with a data processing circuit that uses dual matched filters to verify the consistency of data frames, reducing noise and processor load by ensuring accurate transmission and reception of control signals, and incorporating a combinational determination circuit to manage potential noise impacts on ignition control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the same data is transmitted or received twice in succession to improve communication reliability, then noise resistance is improved, but processor load increases and drive control delay occurs
Solution Approach 1:
The patent divides the communication verification process into two independent matched filters operating in parallel, each processing one data frame. This segmentation allows the system to verify data reliability without requiring sequential processing of duplicate data transmissions, thereby reducing processor load while maintaining communication reliability.
Solution Approach 2:
The patent introduces a combinational determination circuit as an intermediary that receives outputs from both matched filters and determines data validity. This intermediary component consolidates the verification logic, preventing the processor from directly handling the complexity of dual data verification and thus reducing processor load while ensuring reliable communication.
2Reliability
If the same data is transmitted or received twice in succession to improve communication reliability, then noise resistance is improved, but drive control delay occurs
Solution Approach 1:
By segmenting the verification process into parallel matched filters, the system eliminates the sequential waiting time that would occur if data had to be verified in two separate transmission cycles. Both data frames are processed simultaneously, and the drive control can proceed as soon as the combinational determination circuit validates the data, thus reducing drive control delay.
Solution Approach 2:
The patent performs preliminary verification by having both matched filters process data frames in advance and simultaneously feed results to the combinational determination circuit. This preliminary action ensures that data validation is completed before drive control execution without adding sequential delay, as the verification and control preparation occur in parallel.
3Device complexity
If serial communication is used to transmit control signals, then the number of communication lines is reduced, but noise susceptibility increases
Solution Approach 1:
The patent implements a feedback mechanism where the output of each matched filter is fed into the combinational determination circuit, which then determines whether to proceed with drive control. This feedback loop allows the system to detect and reject noisy data frames without requiring additional communication lines, thus maintaining simple serial communication while reducing noise susceptibility through intelligent data validation.
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
The invention, while reducing noise, suppresses a load increase in a processor and a delay in drive control. An engine control unit includes a processor, a driving circuit including a switching element to drive a load such as a fuel injector and an ignition device, and a communication circuit that transmits control signals from the processor to the driving circuit via serial communication. The control signals each include a command frame for controlling the driving circuit and a data frame for driving the load. If a predetermined bits in each of the data frames received from the processor at predetermined time intervals are determined to be the same twice in succession, the engine control unit changes a state of a driving signal 'Drive' for driving the load and thereby changes an operating state of the switching element.