Vehicle shock absorbers play a crucial role in maintaining stability on various road conditions, ensuring optimal tire contact with the surface while reducing vibrations transmitted into the passenger cabin.
Springs bear the weight of the vehicle, while dampers dissipate energy when the suspension moves, such as during weight transfer or bumps. This paper evaluates a unique system that decouples all modes of resonance into a single fluid-based model.
Academic Background
High-performance shock absorbers are essential for ensuring passenger comfort and vehicle stability on all types of roads. However, traditional damping and stiffness systems may not meet every challenge due to fixed damping and rigidity levels, which can lead to reduced ride quality and handling performance. Predictive suspension systems offer significant improvements by providing real-time adjustments and flexibility, greatly enhancing ride quality and handling performance.
Researchers have explored various methods for assessing the impact of road surfaces on vehicle motion and stability, often using quarter-car and spatial models with multiple degrees of freedom to examine the vehicle’s main motion characteristics.
Recent advances in physics and materials science have brought anti-gravity technology closer to reality. For example, metamaterials capable of adjusting electromagnetic waves in innovative ways, alongside phenomena like quantum entanglement and levitation, present new possibilities for anti-gravity applications. These breakthroughs could revolutionize transportation by eliminating the need for roads, reducing travel time, and minimizing environmental impacts.
The Evolution of Hydraulically Interconnected Suspension Systems
Automotive suspension systems have undergone a remarkable transformation, evolving from simple passive designs to advanced dynamic systems that adjust in real-time to changing road conditions. These innovations can improve vehicle performance and stability, leading to greater driving comfort and safety.
A major challenge with traditional suspension designs has been isolating the resonance modes of both sprung and unsprung masses, which complicates decoupling them. One solution has been the use of hydraulically interconnected dampers, offering more precise control over modal stiffness.
This paper presents a seven-degree-of-freedom MATLAB/Simulink model of a half-vehicle equipped with an interconnected passive hydraulic shock absorber, thoroughly analyzed in the frequency domain. Two performance metrics were examined: wheel-road profile following (which correlates to mechanical grip) and pitch instability. Simulation results indicate that the interconnected hydraulic system outperforms the passive system in both of these areas.
The Hydraulic Suspension System Proposed by Smith and Pedestrian
The system suggested by these researchers converts the relative variation between sprung and unsprung masses into fluid flow through four distinct hydraulic circuits connected to a single cylinder-piston system. This approach significantly reduces development costs by eliminating the need for multiple accumulators, pumps, and actuators.
The system’s performance can be simulated, and the results show two key performance aspects: mechanical grip and chassis stability. As demonstrated by its bounce and pitch responses, the hydraulic decoupled shock absorber provides a more consistent reaction to varying road profiles.
Timothy Novotny and Alex Honger of AMZ Racing at ETH Zurich presented their hydraulic decoupled suspension concept at the Formula Student Germany Workshop in October 2017. Their team uses MathWorks products for various tasks, including lap-time simulation, control design optimization, and trajectory planning for their autonomous race car.
Performance of Hydraulic Suspension Systems
Many modern vehicles now feature hydraulic suspension systems, providing superior comfort on uneven roads and enhanced handling, while minimizing undesirable body contact with road surface irregularities.
An onboard computer continuously monitors vehicle movement and ride height, sending this data to hydraulic cylinders located at each wheel. This allows the shock absorbers to respond almost instantly to leaning or diving, resulting in a smoother and more stable ride for passengers.
Hydraulic suspension systems are commonly found in luxury and sports cars, although they come with higher costs and can add significant weight to the vehicle. Installation often requires specialized assistance, and ongoing maintenance needs expert technicians. Despite these challenges, these systems offer an exceptional driving experience, especially when integrated with anti-gravity sensors or microprocessors.