In-Vehicle ECU Error Correction via Dynamic Voltage Adjustment
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Solution Overview
Problem
Existing in-vehicle electronic control units (ECUs) face challenges in accurately estimating the linear function of an amplification circuit's input-output relationship due to limitations in voltage difference between reference signals, leading to incomplete error correction in sensor output signals.
Innovation Solution
The in-vehicle ECU employs a microcomputer-controlled system with first and second voltage generators to adjust input signals to the A/D converter, ensuring they are close to the voltage limits, thereby increasing the voltage difference between signals and enabling accurate identification of the amplification circuit's linear function for precise error correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If constant voltage signals (0V and specified voltage) are used for error correction, then the correction method is simple, but the voltage difference between signals is insufficient leading to inaccurate linear function estimation
Solution Approach 1:
The patent applies dynamics by making the voltage signals variable instead of constant. The microcomputer dynamically adjusts the voltage levels of the first and second signals to maximize the voltage difference between them, thereby improving the accuracy of linear function estimation while maintaining system simplicity through automated control.
Solution Approach 2:
The patent changes the voltage parameters of the test signals from fixed constant values to variable values that can be adjusted by the microcomputer. By optimizing the voltage difference between the first and second signals, the system achieves more accurate estimation of the amplification circuit's linear function while keeping the correction process automated and simple.
2Measurement precision
If the voltage difference between first and second signals is increased to improve linear function estimation accuracy, then measurement precision improves, but the A/D converter voltage range limits the maximum achievable voltage difference
Solution Approach 1:
The system dynamically adjusts the voltage levels within the A/D converter's acceptable input range to maximize the voltage difference. The microcomputer optimizes the voltage allocation between the first and second signals, ensuring they remain within the 0V to 5V range while achieving the largest possible voltage difference for accurate estimation.
Solution Approach 2:
The patent optimizes the voltage parameters of the test signals by adjusting them to be as close as possible to the A/D converter's input voltage limits (0V and 5V). This parameter optimization allows the system to achieve maximum voltage difference within the device constraints, thereby improving estimation accuracy without requiring hardware modifications.
3Reliability
If error correction is performed using linear function estimation from error-ridden A/D conversion values, then error correction is achieved, but the correction accuracy is limited by noise and environmental factors
Solution Approach 1:
The patent applies preliminary action by performing error correction before final signal processing. The microcomputer estimates the linear function of the amplification circuit using test signals and applies this estimation to correct errors in the actual sensor output signals, thereby improving the accuracy of subsequent measurements and control operations.
Solution Approach 2:
The system uses feedback by continuously monitoring the A/D conversion values and adjusting the voltage levels of the test signals to maximize the voltage difference. The microcomputer uses the conversion values from both the first and second signals to estimate the linear function and apply error correction, creating a closed-loop system that improves accuracy despite noise and environmental variations.
Data Source
AI summary
An in-vehicle electronic control unit (ECU) for correcting an error introduced to a sensor output signal as a result of amplification is provided. An output voltage of first and second voltage generators and after-amplification voltages of such output voltages are respectively A/D converted for input into a linear function. A microcomputer adjusts the output voltage of the first and second voltage generators which are amplified by the amplification circuit so that the output signals of the first and second voltage generators are adjusted to increase a voltage difference between the two. The increased voltage difference allows accurate identification of the linear function and removal of the error that is introduced to the sensor output signal during the course of processing by the amplification circuit.