Rear Active Suspension Camber Toe Control
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Solution Overview
Problem
Existing active suspension control methods for vehicles, particularly high-performance sports cars, fail to optimally manage rear camber and toe angles, leading to suboptimal tire-ground contact patch under dynamic conditions.
Innovation Solution
A control method for rear active suspensions using electromagnetic linear actuators driven by an electronic control unit, connected to a triaxial gyroscope and satellite positioning system, to dynamically adjust camber and toe angles in real-time, optimizing tire contact patch by measuring and responding to vehicle accelerations and geo-referenced position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional passive suspension is used, then the suspension structure is simple and cost-effective, but the camber and toe angles cannot be optimized under dynamic conditions
Solution Approach 1:
The patent applies the dynamics principle by replacing static suspension arms with active linear actuators that can dynamically adjust the camber and toe angles in real-time based on vehicle operating conditions. This allows the suspension geometry to adapt to changing forces and moments, optimizing tire-ground contact patch dynamically rather than being fixed as in traditional passive suspensions.
2Adaptability or versatility
If active suspension with linear actuators is used, then camber and toe angles can be controlled, but the control system becomes complex and expensive
Solution Approach 1:
The patent implements feedback control by using sensors to continuously monitor the actual camber and toe angles, comparing them with target values, and adjusting the linear actuators accordingly. This closed-loop control system ensures accurate maintenance of optimal suspension geometry while providing a structured approach to managing the complexity of active suspension control.
Solution Approach 2:
The patent replaces complex mechanical suspension arms with electrically-controlled linear actuators, substituting mechanical geometry adjustments with electromechanical actuation. This substitution enables more precise and programmable control of camber and toe angles while reducing the mechanical complexity of linkage systems.
3Reliability
If nominal camber and toe angles are optimized for general performance, then average tire contact is improved, but optimal contact is never achieved in specific dynamic conditions
Solution Approach 1:
The patent transforms the static nominal angle setting into a dynamic adjustment system where camber and toe angles are continuously modified based on real-time sensor data about vehicle forces, moments, and operating conditions. This enables the system to achieve optimal tire-ground contact for each specific dynamic situation rather than relying on compromise nominal values.
Solution Approach 2:
The patent changes the suspension geometry parameters (camber and toe angles) dynamically by controlling the length and position of linear actuators. This allows the system to adjust critical geometric parameters in response to varying operational conditions, transitioning from fixed parameter design to adaptive parameter control.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method allows for continuous, optimal adjustment of camber and toe angles, enhancing tire-ground contact and vehicle performance by optimizing force distribution and stability, especially during dynamic maneuvers, thereby improving handling and traction.
Implementation Method 1
the suspension arms are replaced by corresponding linear actuators which are driven to vary their length in controlled manner
Implementation Method 2
connected to a triaxial gyroscope which is integral with the vehicle chassis and measures linear accelerations with respect to the ground and angular accelerations with respect to the ground in real time
Data Source
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AI summary
A control method of the toe and camber angles of rear active suspensions (12) of a vehicle (1); the control method includes the steps of: detecting when the vehicle (1) follows a curved trajectory (T); conferring negative toe angles combined with zero camber angles to the rear active suspensions (12), when starting the curved trajectory (T) and when the vehicle (1) enters the curved trajectory (T); and conferring positive camber angles combined with negative toe angles to the rear active suspensions (12), while following the curved trajectory (T) and when the vehicle (1) is inscribed in the curved trajectory (T).