Solenoid Valve Control Apparatus for Acoustic Noise Reduction
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Solution Overview
Problem
Existing solenoid valve control systems generate acoustic noise due to fixed-frequency driving signals, which can disrupt the operation of electronically controlled brake systems like ABS, leading to unstable braking performance.
Innovation Solution
A solenoid valve control apparatus and method that vary the frequency of the driving signal over time during current control, using a Micro Control Unit (MCU) and a Proportional-Integral (PI) controller to adjust the current and frequency of the signal supplied to the solenoid coil, reducing acoustic noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a fixed frequency driving signal is used to control the solenoid valve, then the current control is simple and stable, but acoustic noise is generated in the solenoid valve assembly
Solution Approach 1:
The patent applies dynamics by transforming the fixed-frequency driving signal into a variable-frequency driving signal. The frequency of the driving signal is dynamically adjusted during the current control process, which prevents the generation of acoustic noise while maintaining effective solenoid valve operation. This dynamic frequency adjustment resolves the contradiction between noise reduction and control simplicity.
Solution Approach 2:
The patent changes the frequency parameter of the driving signal from a fixed value to a variable value. By modifying this key parameter, the system eliminates acoustic noise generation while preserving the current control functionality. The frequency parameter is adjusted according to the control stage, achieving noise reduction without excessive system complexity.
2Object-generated harmful factors
If the frequency of the driving signal is varied to reduce acoustic noise, then noise is reduced, but the control system complexity increases
Solution Approach 1:
The patent employs feedback mechanisms where the ECU monitors the current flowing in the solenoid coil through a shunt resistance unit and adjusts the driving signal frequency based on the monitored results. This feedback loop ensures that the variable frequency control achieves noise reduction while maintaining reliable and stable brake system operation, resolving the contradiction between noise reduction and system reliability.
Solution Approach 2:
The patent uses periodic action by implementing different frequency stages during the current control process. The driving signal frequency is adjusted in different stages (initial stage and subsequent stages), creating a structured periodic variation that reduces acoustic noise while ensuring stable and reliable brake system performance through controlled frequency transitions.
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
The variable frequency driving signal effectively reduces acoustic noise in solenoid valves, enhancing the stability and reliability of brake system operations by minimizing noise interference.
Implementation Method 1
The solenoid valve is opened and closed by current supplied to a solenoid coil therein
Data Source
AI summary
Disclosed herein are a solenoid valve control apparatus and method. The solenoid valve control apparatus to control a solenoid valve which include a solenoid coil and is opened and closed by current supplied to the solenoid coil, includes a switching unit which switches the current supplied to the solenoid coil, a pre-driver unit which outputs a driving signal to drive the switching unit, a current detection unit which detects the current flowing in the solenoid coil, and an MCU which controls the pre-driver unit so as to output the driving signal from the pre-driver unit to the switching unit such that a value of the current detected by the current detection unit reaches a target current value during current control of the solenoid valve and controls the pre-driver unit such that a frequency of the output driving signal is varied during output of the driving signal.