Variable Damper Control for Yaw-Induced Vehicle Roll Stability
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Solution Overview
Problem
The existing vehicle motion control apparatuses fail to effectively manage the change in roll posture during yaw moment control, leading to excessive changes in roll posture due to moment control, which can cause discomfort for the driver and occupants.
Innovation Solution
A vehicle motion control apparatus that includes a control unit to adjust the forces of damping force variable dampers based on the turn state of the vehicle, calculating a target roll amount and estimating the roll amount occurring due to lateral acceleration and yaw moment command, and outputting commands to approach the target roll amount, thereby reducing the promotion or suppression of roll posture changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If moment control is executed to generate different driving forces or braking forces on left and right wheels during steering, then yaw moment control is achieved, but the change in roll posture becomes excessively large or small due to roll moment caused by moment control
Solution Approach 1:
The control unit calculates a roll moment that opposes the roll moment generated by moment control, and generates driving/braking forces specifically to produce this counteracting roll moment. This preliminary anti-action prevents excessive roll posture changes before they occur, while maintaining the desired yaw moment control effectiveness
Solution Approach 2:
The invention applies differential driving/braking forces to specific wheels (left and right wheels) based on their individual positions and the calculated roll moment requirements. Each wheel receives customized force adjustments tailored to local roll control needs, rather than uniform force distribution
2Ease of operation
If damping force variable dampers are controlled in consideration of GV control only, then pitch behavior is managed, but roll posture control is insufficient when moment control is also executed
Solution Approach 1:
The control unit integrates both GV control (for pitch behavior) and moment control (for yaw moment) into a unified control framework. By merging these control objectives and calculating combined roll and pitch moments, the system manages both pitch and roll postures simultaneously through coordinated damping force adjustments
Solution Approach 2:
The damping force variable dampers are designed to serve multiple functions: controlling pitch behavior through GV control, controlling roll posture through moment control consideration, and maintaining overall vehicle stability. The control unit adjusts damper forces to achieve multiple control objectives concurrently
Data Source
AI summary
In a vehicle, GV control and M+ control are executed by generating braking/driving forces from a brake hydraulic pressure control device and a drive device during steering. A controller estimates (calculates), by a posture estimation unit, a pitch amount and a roll amount (predicted pitch rate and predicted roll rate) that occur in the vehicle through use of a moment command of the M+ control and a longitudinal G command of the GV control. The controller adjusts damping forces of damping force variable dampers through use of the estimated pitch amount and the estimated roll amount (predicted pitch rate and predicted roll rate) so that a pitch amount calculated by a pitch control unit and a roll amount calculated by a roll suppression unit approach respective target values.