Microcomputer Time Synchronization Using a Waveform Generation Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Automatic driving systems require highly accurate time synchronization between multiple arithmetic processing devices to integrate sensor information effectively, but existing methods like PTL 1 can cause delays due to interrupt processing and are not efficient in removing transmission delays.
Innovation Solution
A waveform generation circuit is used between a master microcomputer and slave microcomputers for time synchronization, where the master microcomputer outputs a reset signal synchronized with time, and the slave microcomputers measure voltage values of the waveform signal to detect time, allowing for accurate and delay-reduced synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If interrupt function is used for time synchronization (as in PTL 1), then time synchronization can be achieved, but arithmetic processing may be suspended causing increased processing time and potential timeout
Solution Approach 1:
A waveform generation circuit is introduced as an intermediary device between the master microcomputer and slave microcomputers. The master microcomputer generates a reset signal that triggers the waveform generation circuit to produce a precise waveform signal, which is then measured by slave microcomputers to determine synchronization time. This intermediary approach allows time synchronization to be achieved without requiring the slave microcomputers to execute interrupt routines, thereby avoiding suspension of their arithmetic processing while maintaining high synchronization accuracy.
2Measurement precision
If serial communication is used to exchange time information, then time synchronization can be achieved, but transmission delay cannot be removed
Solution Approach 1:
The patent replaces the software-based serial communication method with a hardware-based waveform signal transmission approach. Instead of exchanging time information through software communication protocols that introduce variable delays, the system uses a dedicated waveform generation circuit that produces a precise voltage waveform signal. The slave microcomputers measure the voltage value of this signal to directly determine the synchronization time, eliminating the unpredictable delays associated with software-based serial communication while maintaining high accuracy.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables highly accurate time synchronization between microcomputers with minimal delay, ensuring reliable and efficient operation of automatic driving systems without hindering arithmetic processing.
Implementation Method 1
the waveform generation circuit outputs a waveform signal corresponding to a change in time of the master microcomputer
Data Source
AI summary
There is provided an electronic control device that performs distributed processing using a plurality of microcomputers and can perform highly accurate time synchronization between the microcomputers with less delay without hindering arithmetic processing of each microcomputer. The device includes a plurality of microcomputers, and a waveform generation circuit connected between a master microcomputer serving as a time synchronization source and a slave microcomputer that performs time synchronization, among the plurality of microcomputers, wherein the master microcomputer outputs a reset signal synchronized with time to the waveform generation circuit, the waveform generation circuit outputs a waveform signal corresponding to a change in time of the master microcomputer, to the slave microcomputer, and the slave microcomputer measures a voltage value of the waveform signal and detects time corresponding to the measured voltage value.