Vehicle Roll Damping Control Using Corrected Target Roll Moment
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Solution Overview
Problem
Existing vibration damping control systems for vehicles struggle to accurately detect wheel accelerations over time and effectively damp roll vibrations, especially as natural frequency and damping ratio vary with vehicle speed, leading to inadequate roll vibration control.
Innovation Solution
A roll vibration damping control system that includes a roll angular acceleration detector, an actuator, and an electronic control unit to compute and apply a target roll moment by integrating roll moment of inertia, damping coefficient, and equivalent stiffness, with a correction roll moment based on lateral force and vehicle speed, while applying high-pass and low-pass filters to reduce phase shifts and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vibration damping control is implemented using skyhook control or negative skyhook control, then high-frequency vibrations are effectively damped, but roll vibrations cannot be effectively damped because the single-wheel vehicle model does not account for roll motion characteristics that vary with vehicle speed
Solution Approach 1:
The control system dynamically adjusts the target roll moment based on detected roll angular acceleration and vehicle speed. The electronic control unit computes the target roll moment by integrating roll moment of inertia, damping coefficient, and equivalent stiffness parameters that are updated according to vehicle speed, allowing the system to adapt to varying roll characteristics at different speeds
Solution Approach 2:
The system changes control parameters (roll moment of inertia, damping coefficient, equivalent stiffness) based on vehicle speed. The electronic control unit stores multiple sets of parameters corresponding to different vehicle speed ranges and selects appropriate parameters to compute the target roll moment, ensuring effective roll vibration damping across various operating conditions
2Measurement precision
If acceleration sensors are installed on wheels to detect up and down accelerations, then wheel stroke speeds can be obtained for vibration damping control, but the sensors cannot accurately detect accelerations over extended periods because they are constantly subjected to road surface vibrations
Solution Approach 1:
The system uses an intermediary computational approach by detecting roll angular acceleration of the vehicle body (which is more stable) and computing wheel-related parameters through integration and mathematical relationships rather than directly measuring wheel accelerations with sensors subjected to constant vibration
Solution Approach 2:
The system replaces direct mechanical acceleration sensing on wheels with a computational model that uses roll angular acceleration detection and mathematical integration to derive the necessary control parameters, substituting physical sensor measurement with computational derivation
Data Source
AI summary
A roll vibration damping control system includes an electronic control unit configured to: compute a sum of a product of a roll moment of inertia and a roll angular acceleration of a vehicle body, a product of a roll damping coefficient and a first-order integral of the roll angular acceleration, and a product of an equivalent roll stiffness of the vehicle and a second-order integral of the roll angular acceleration, as a controlled roll moment to be applied to the vehicle body; compute a roll moment around a center of gravity of a sprung mass as a correction roll moment, the roll moment being generated by lateral force on wheels due to roll motion; and compute a target roll moment based on a value obtained by correcting the controlled roll moment with the correction roll moment.