Vehicle Motion Control Device Dynamic Gain Adjustment
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Solution Overview
Problem
Existing vehicle motion control systems, such as G-Vectoring Control, often result in hypersensitive reactions during normal operation, leading to jerking motions and increased actuator stress, which limits their application range and increases costs.
Innovation Solution
A vehicle motion control device that includes a risk potential estimator, a longitudinal motion controller, and a gain adjustor, which adjusts the gain based on estimated risk potential to enhance emergency detour steering assistance while minimizing jerking motions during normal operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the gain (KGyV) to be multiplied by the lateral jerk (Gy_dot) increases to enhance detour performance, then the deceleration basically increases and velocity during control operation decreases, but hypersensitive reaction occurs even in response to a minute steering operation during normal operation, which causes the driver to experience a jerking forward motion of the vehicle
Solution Approach 1:
The patent applies dynamics by making the gain KGyV adjustable rather than fixed. The gain is dynamically changed based on the absolute value of steering angle |δ| and steering angular velocity |δ'|. When |δ| ≥ δ0 or |δ'| ≥ δ'0, the gain is set to a first value (higher) to enhance detour performance. When |δ| < δ0 and |δ'| < δ'0, the gain is set to a second value (lower) to prevent hypersensitive reactions during normal operation. This dynamic adjustment resolves the contradiction between needing high gain for emergency detour and low gain for normal comfort.
2Speed
If the gain (KGyV) is increased to enhance emergency detour performance, then the deceleration basically increases, but actuator conditions (responsiveness, durability, NVH performance) become strict and cost increases
Solution Approach 1:
The patent uses dynamic gain adjustment based on steering conditions to reduce actuator stress during normal operation. By setting the gain to a lower second value when |δ| < δ0 and |δ'| < δ'0, the actuator operates under less stringent conditions during normal driving, improving durability and reducing NVH issues. The higher first value is only applied during emergency detour when |δ| ≥ δ0 or |δ'| ≥ δ'0, minimizing overall actuator stress and associated costs.
3Ease of operation
If braking control is prohibited for a certain period when steering angle or steering angular velocity exceeds threshold to allow emergency detour, then the driver can steer freely, but the detour operation is not assisted during the prohibited period
Solution Approach 1:
The patent dynamically adjusts the longitudinal motion control command Gx based on steering conditions rather than simply prohibiting braking control. When |δ| ≥ δ0 or |δ'| ≥ δ'0, the system generates a larger control command (first control command) to assist emergency detour. When |δ| < δ0 and |δ'| < δ'0, the system generates a smaller control command (second control command) for normal operation. This dynamic control approach maintains both steering freedom and continuous detour assistance, resolving the contradiction between unrestricted steering and reliable detour support.
Data Source
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AI summary
In order to reliably assist a driver in emergency detour steering without causing a jerking forward motion of the vehicle during normal operation, a vehicle motion control device includes: a risk potential estimator that estimates a risk potential of a vehicle based on input external information and vehicle information; a vehicle longitudinal motion controller that generates a longitudinal motion control command of the vehicle based on a vehicle lateral jerk and a predetermined gain; and a gain adjustor that adjusts the gain, in which the gain adjustor adjusts the gain based on the risk potential estimated by the risk potential estimator.