Vehicle Support Structure Stiffness Control via Magnetorheological Fluid
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Solution Overview
Problem
Existing vehicle support structures lack effective control over stiffness during acceleration, braking, cornering, and collision, leading to inadequate vibration management and energy absorption, which can result in undesirable resonance and increased risk of injury.
Innovation Solution
A vehicle control system that utilizes a magnetic field generator and electronic controller to adjust the stiffness of support structures, such as those with magnetorheological or electrorheological fluids, based on real-time data from sensors like acceleration, braking, and collision sensors to optimize ride and handling characteristics and maximize energy absorption during collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the support structure uses fixed stiffness material, then the structure is simple and reliable, but it cannot adapt to different driving conditions and collision scenarios
Solution Approach 1:
The support structure incorporates magnetorheological or electrorheological materials that can dynamically change their stiffness properties in response to external stimuli (magnetic or electric fields). This allows the structure to adapt its mechanical properties in real-time based on driving conditions, transitioning from a static structure to a dynamic one that can optimize performance for different scenarios including normal operation and collision events.
Solution Approach 2:
The invention changes the physical parameter of stiffness by utilizing materials whose mechanical properties can be modified through external fields. By applying magnetic fields to magnetorheological materials or electric fields to electrorheological materials, the stiffness of the support structure can be continuously adjusted, enabling adaptation to various driving conditions without requiring multiple separate structural configurations.
2Stability of the object's composition
If the support structure increases stiffness to improve stability during acceleration and cornering, then handling improves, but energy absorption capability during collision decreases
Solution Approach 1:
The support structure uses dynamically adjustable stiffness through magnetorheological or electrorheological materials that can transition between soft and rigid states. During acceleration and cornering, the materials are activated to increase stiffness for improved stability and handling. During collision events, the materials can be deactivated or adjusted to reduce stiffness, enabling the structure to deform and absorb impact energy effectively, thus resolving the contradiction between stability and energy absorption.
Solution Approach 2:
The system employs periodic or conditional activation of the magnetic or electric fields based on detected driving conditions. Sensors monitor vehicle operation and trigger field application during maneuvers requiring stability (acceleration, cornering) while allowing the materials to remain in a softer state during collision events, creating a periodic cycle of stiffness adjustment that optimizes both stability and energy absorption capabilities at different times.
3Strength
If the support structure decreases stiffness to maximize energy absorption during collision, then safety improves, but vibration control and resonance prevention during normal operation worsen
Solution Approach 1:
The support structure utilizes magnetorheological or electrorheological materials that can dynamically adjust their stiffness properties. During normal operation, the materials are activated through applied fields to increase stiffness, providing effective vibration control and resonance prevention. During collision events, the fields are reduced or removed, allowing the materials to soften and maximize energy absorption capability, thus resolving the contradiction between vibration management and energy absorption.
Solution Approach 2:
The system incorporates sensors that continuously monitor driving conditions and provide feedback to the control system. Based on this feedback, the control system adjusts the application of magnetic or electric fields to the rheological materials, increasing stiffness during normal operation for vibration control and decreasing stiffness during collision events for energy absorption, thereby dynamically optimizing both vibration management and safety performance.
4Adaptability or versatility
If magnetorheological or electrorheological materials are embedded in support structures, then stiffness control capability is achieved, but manufacturing complexity and cost increase
Solution Approach 1:
The invention embeds magnetorheological or electrorheological materials within the support structure, creating a composite material system that combines the structural properties of the base material with the field-responsive properties of the rheological materials. This composite approach enables stiffness control capability while integrating the functional materials directly into the structural components, though it does increase manufacturing complexity compared to traditional homogeneous materials.
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
The system effectively manages stiffness to enhance vehicle stability, comfort, and safety by adjusting support structure properties in response to driving conditions, minimizing the force of collisions and improving energy absorption.
Implementation Method 1
The MR layer 12 is in liquid form when there is no external stimuli. Applying a magnetic field to the beam or support structure 10 shown in Fig. 1 changes the MR layer to become more like a solid gel.
Implementation Method 2
Known electrorheological (ER) materials or layers have also been embedded or otherwise disposed, for instance, in a laminated composite for controlling vibration thereof in a similar manner by applying electricity thereto.
Implementation Method 3
A magnetic field generator and at least one support structure changing properties in response to a magnetic field.
Data Source
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AI summary
A method and vehicle control system for controlling stiffness of at least one support structure (10, 84, 94) of a vehicle includes at least one of an acceleration sensor (64), a braking sensor (68) and a corner sensor (66) for providing a driving condition of the vehicle. A controller (52) obtains information from the sensors to determine the driving condition and control the stiffness of a support structure (10, 84, 94) of the vehicle. A magnetic field generator (80) provides a magnetic field to control the stiffness of the support structure (10, 84, 94) having a magnetorheological fluid or elastomer. An electrical source (90) provides electrical current to a support structure (10, 84, 94) including an electrorheological fluid or a support structure (10, 84, 94) including a meta-material. When a vehicle collision is predicted no energy is provided to the support structure (10, 84, 94) to minimize the stiffness and maximize energy absorbance by the support structure (10, 84, 94) in a collision.