Lateral Tip-Over Prevention via Adaptive Braking States
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Solution Overview
Problem
Existing methods for preventing motor vehicle tip-over primarily focus on longitudinal stability and do not effectively address lateral tip-over risks, especially in highly dynamic driving situations, as they lack consideration of previous driving states and driver inputs.
Innovation Solution
A method and apparatus that utilize a finite number of predefined driving states, determined by sensor signals such as yaw rate, transverse acceleration, steering angle, and wheel rotation speeds, to implement adaptive braking interventions, including pre-filling wheel brake cylinders, to prevent lateral tip-over by employing a hybrid state machine within the vehicle dynamics regulation system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional tip-over prevention methods focusing on longitudinal stability are used, then longitudinal stability is improved, but lateral tip-over protection in dynamic driving situations deteriorates
Solution Approach 1:
The patent segments the stability regulation into separate longitudinal and lateral components. The lateral tip-over prevention is handled as a distinct function with dedicated threshold evaluation and braking intervention logic, independent from the longitudinal stability regulation. This segmentation allows each function to be optimized separately, resolving the contradiction between longitudinal stability and lateral tip-over prevention.
Solution Approach 2:
The patent introduces dynamic threshold values for lateral acceleration that adapt based on the current driving state and longitudinal acceleration. The threshold is not fixed but varies dynamically to account for different driving conditions, enabling effective lateral tip-over prevention while maintaining longitudinal stability across diverse operating scenarios.
2Speed
If regulation is based only on present vehicle-dynamics situation, then response speed is improved, but adaptation to overall driving situation deteriorates
Solution Approach 1:
The patent implements preliminary action by defining multiple driving states (normal, dynamic, extreme) in advance and pre-determining the appropriate threshold values and braking strategies for each state. The system continuously monitors and transitions between these predefined states, allowing it to quickly adapt to changing driving situations without complex real-time calculations, thus maintaining fast response while achieving good adaptability.
3Force
If braking intervention is applied without pre-filling brake cylinders, then braking effectiveness is improved, but braking reaction time deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-filling the brake cylinders with hydraulic pressure before actual braking is required. When tip-over risk is detected, the brakes can be applied immediately with full effectiveness since the hydraulic pressure is already in place. This eliminates the delay associated with building up brake pressure during emergency braking, simultaneously achieving fast reaction time and high braking effectiveness.
Data Source
AI summary
The invention relates to a method for preventing tip-over of a motor vehicle in the lateral direction,in which a finite number of predefined driving states is specified;in which a determination is made as to which of the predefined driving states the vehicle is in instantaneously,the predefined driving state thus determined being dependent on sensor signals and on that predefined driving state in which the vehicle was most recently; andas a function of the predefined driving state instantaneously present, at least one braking intervention is carried out in order to prevent the tip-over.