Futuristic unmanned ground vehicle navigating rough terrain with advanced suspension.

Smooth Ride Ahead: Unveiling the Future of Vehicle Suspension Systems

Theo Raines in Tech & Innovation June 2025 • 4 min read.

"Dive into the innovative world of shock absorber technology and discover how advanced modeling techniques are paving the way for safer, more comfortable unmanned vehicles."

Unmanned Ground Vehicles (UGVs) are increasingly prevalent across diverse sectors, from logistics and surveillance to hazardous environment exploration. A critical component ensuring their effectiveness and safety is the suspension system. These systems must withstand demanding conditions while maintaining vehicle stability and ride comfort. The delicate balance between these factors is paramount for the reliable operation of electronic control systems.

Traditional methods of physical prototyping are often costly and time-intensive. Virtual models offer a streamlined alternative, allowing engineers to simulate and optimize suspension designs before committing to physical production. However, the accuracy of these virtual models hinges on the comprehensive representation of each suspension component, particularly the shock absorber.

This article explores the crucial role of shock absorber modeling in UGV design. We'll delve into the mathematical models used to characterize shock absorber behavior, focusing on the modified Bouc-Wen model (Spencer model) and its application in Matlab/Simulink for simulation and analysis. By understanding these advanced techniques, we can unlock the potential for enhanced UGV performance and safety.

The Science of Shock Absorber Modeling

Futuristic unmanned ground vehicle navigating rough terrain with advanced suspension.

Modeling shock absorbers accurately is a complex task, given their non-linear behavior. Two primary approaches exist: parametric and non-parametric modeling. Non-parametric models rely on direct device characteristics, while parametric models, the focus here, simulate the force response of the shock absorber using mathematical functions adapted to experimental measurements. These models often represent the shock absorber as an assembly of mechanical components, such as springs and viscous dampers.

One fundamental parametric model is the Kelvin-Voight model, which combines a spring (representing stiffness) and a damper (representing energy dissipation) in parallel. While simple, this model often falls short of capturing the intricate dynamics of real-world shock absorbers, especially their non-linear characteristics. This is where more sophisticated models like the Bouc-Wen model come into play.

The Bouc-Wen model offers several advantages:

Captures hysteretic behavior (energy dissipation during loading and unloading).
Can represent various shock absorber characteristics with a single model structure.
Involves an inherent simplicity compared to overly complex models.
Its hysteretic loop shape is controlled by adjustable parameters.

The Bouc-Wen model utilizes a non-linear differential equation with a 'memory variable' to represent hysteresis. The Spencer model, a modified version of Bouc-Wen, further refines the representation of shock absorber behavior. This enhanced model incorporates additional parameters and equations to capture more nuanced characteristics, allowing for more accurate simulations. The model's parameters are critical. These parameters are adjusted to match the experimental data, ensuring the simulation closely mirrors real-world performance.

The Road Ahead: Optimizing UGV Performance

Accurately modeling shock absorber characteristics is crucial for designing high-performance UGVs. The modified Bouc-Wen model, as demonstrated through simulation and experimental validation, offers a powerful tool for achieving this goal. While parameter identification remains a challenge, ongoing research focuses on developing robust methods to streamline this process. Future work will integrate these refined shock absorber models into full-body UGV simulations, paving the way for optimized suspension systems and enhanced vehicle dynamics.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.2478/v10228-012-0008-5, Alternate LINK

Title: Characteristic Model Of A Shock Absorber In An Unmanned Ground Vehicle

Journal: Scientific Proceedings Faculty of Mechanical Engineering STU in Bratislava

Publisher: Walter de Gruyter GmbH

Authors: Ján Danko, Tomáš Milesich, Martin Bugár, Juraj Madarás

Published: 2012-01-01

Everything You Need To Know

What is the Spencer model, and how does it improve upon the original Bouc-Wen model?

The Spencer model is a modified version of the Bouc-Wen model. It enhances the representation of shock absorber behavior by incorporating additional parameters and equations. This allows for a more accurate simulation of nuanced shock absorber characteristics compared to the original Bouc-Wen model.

Why are mathematical models crucial in the design of Unmanned Ground Vehicle (UGV) suspension systems?

Mathematical models are essential because they offer a streamlined alternative to traditional physical prototyping, which is often costly and time-intensive. Virtual models allow engineers to simulate and optimize suspension designs before committing to physical production. The accuracy of these virtual models relies on the comprehensive representation of each suspension component, particularly the shock absorber.

What is the difference between parametric and non-parametric modeling techniques for shock absorbers, and which specific models fall under the parametric category?

Non-parametric models rely on direct device characteristics, whereas parametric models simulate the force response of the shock absorber using mathematical functions adapted to experimental measurements. Parametric models, like the Kelvin-Voight model and the Bouc-Wen model, often represent the shock absorber as an assembly of mechanical components, such as springs and viscous dampers.

What are the advantages of using the Bouc-Wen model for shock absorber simulation, and how does it compare to simpler models like the Kelvin-Voight model?

The Bouc-Wen model is advantageous because it captures hysteretic behavior, can represent various shock absorber characteristics with a single model structure, and has an inherent simplicity compared to overly complex models. Additionally, its hysteretic loop shape is controlled by adjustable parameters. This contrasts with simpler models like the Kelvin-Voight model, which often fails to capture the intricate, non-linear dynamics of real-world shock absorbers.

What are the current challenges and future directions in optimizing UGV performance using the modified Bouc-Wen model, particularly concerning parameter identification?

Parameter identification, the process of tuning the model's parameters to match experimental data, remains a significant challenge. Ongoing research focuses on developing robust methods to streamline this process. Future work involves integrating refined shock absorber models into full-body UGV simulations, paving the way for optimized suspension systems and enhanced vehicle dynamics. Successfully addressing parameter identification is crucial for maximizing the effectiveness of the modified Bouc-Wen model in UGV design.