Vehicle Damping Control Using Frequency-Split Road Preview Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing damping control systems for vehicles face inaccuracies in controlling the damping force due to misalignment between the position where the control force is generated and the predicted wheel passage position, especially when unsprung displacement-related values have high time change rates, leading to reduced effectiveness in vibration reduction.
Innovation Solution
A damping control apparatus that utilizes a combination of high-pass and low-pass filter processing on road surface displacement-related values to calculate a target control force, with high-pass filtering used in the high frequency region and low-pass filtering in the low to medium frequency region, to reduce errors caused by misalignment and improve accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If damping control is performed using preview reference data based on sensing data acquired by a preview sensor, then it is possible to damp the sprung without delay, but the position where a control force is generated and a predicted wheel passage position are more likely to deviate when unsprung displacement-related values have a high time change rate
Solution Approach 1:
The patent applies different filter processing parameters (high-pass vs. low-pass) based on the frequency characteristics of road surface displacement signals. By changing the processing method according to signal frequency, the system maintains both timely response and position accuracy across different operating conditions.
Solution Approach 2:
The patent dynamically selects different filter processing methods (high-pass or low-pass) based on the actual frequency characteristics of the road surface displacement signal. This dynamic adaptation allows the system to optimize between response speed and position accuracy depending on the input signal characteristics.
2Force
If damping control is performed using preview reference data stored in a server with wireless communication, then road surface information can be acquired in advance, but the position where a control force is generated and a predicted wheel passage position are more likely to deviate compared to using on-board sensor detection
Solution Approach 1:
The patent changes the processing parameters (filter type) based on the frequency characteristics of the acquired road surface displacement signal. This allows the system to maintain position alignment accuracy while utilizing advance road surface information from external servers or sensors.
Solution Approach 2:
The patent introduces filter processing as an intermediary step between acquiring road surface displacement information and generating control forces. This intermediary processing corrects position deviations caused by using preview data from external sources.
3Measurement precision
If high-pass filter processing is applied to road surface displacement-related values, then errors due to misalignment can be reduced in the high frequency region, but low to medium frequency components may be attenuated
Solution Approach 1:
The patent dynamically selects between high-pass and low-pass filter processing based on the frequency characteristics of the road surface displacement signal. When high-frequency components dominate, high-pass filtering is applied to reduce misalignment errors; when low-to-medium frequency components are significant, low-pass filtering is used to preserve signal energy.
Solution Approach 2:
The patent changes the filter processing parameters (cutoff frequency, filter type) based on the actual signal characteristics. This adaptive parameter adjustment ensures optimal balance between position alignment accuracy and signal energy preservation across different driving conditions.
Data Source
AI summary
A damping control apparatus has a control unit that controls an active actuator that generates a control force for damping a sprung, and the control unit determines a predicted wheel passage position where a wheel is predicted to pass, performs a high-pass filtering on a first road surface displacement-related value, performs a low-pass filtering on a second road surface displacement-related value, calculates a target control force for damping the sprung when the wheel passes through the predicted wheel passage position based on a sum of the first road surface displacement-related value after high-pass filtering and the second road surface displacement-related value after low-pass filtering, and the second road surface displacement-related value has a higher possibility that a position where a control force corresponding to the target control force is generated misaligns with the predicted wheel passage position as compared with the first road surface displacement-related value.