This presentation summarizes a project on modeling and simulating a semi-active suspension system. The project aims to design a suspension that can electronically adjust damping forces in response to road conditions to enhance stability, safety, and ride comfort. The team will develop a mathematical model, run simulations in MATLAB Simulink, and iterate on the design to optimize performance. A literature review covered research on using magnetorheological dampers and PID controllers to improve suspension. The methodology outlines forming models, parameters, simulations, analysis, and iterations. Tasks are scheduled on a Gantt chart. In conclusion, suspension systems have advanced significantly and this project will demonstrate and refine the performance of a semi-active system.

1. Presentation on Modeling and
Simulation of Semi - Active
Suspension System
Presented By:
Mausam Bista (PURO76BME049)
Nabin Timilsina(PUR076BME053)
Narayan Khanal(PUR076BME055)
Nirjan Palungwa (PUR076BME062
Sangeet Gurung (PUR076BME080)
Presented To:
Department of Mechanical
Engineering, Purwanchal
Campus
Dharan

2. Abstract
Semi-adaptive suspension is a new type of suspension system that uses sensors and
computers to adjust the stiffness of the shock absorbers in real time.By proactively
adapting damping rates and ride height, the system enhances vehicle stability,
improves safety, and extends the lifespan of vehicle components. This allows the
system to provide a more comfortable and safer ride.
Our approach involves mathematical modeling, simulations, and multiple iterations
to validate the system's performance. The simulation process is to be done by using
simulink of MATLAB software.

3. Introduction
1. A good suspension system is required to
provide better traction of vehicle’s tyres
on road surface and absorb shock to
provide comfort for passengers.
2. Dampers reduce the effect of a sudden
bump by smoothing out the shock.
3. To isolate the frame of the vehicle from
road disturbances.

4. Types Of Suspension System
1. Passive suspension system:
● Passive suspension systems use fixed settings for springs
and dampers that remain unchanged regardless of road
conditions or driving circumstances.
● This lack of adaptability can lead to drawbacks in ride
comfort, handling, and traction, as these systems cannot
optimize their performance based on real-time road
conditions or driver preferences.

5. 2. Semi- active suspension system:
● Semi-active suspension systems utilize specialized
dampers that can be adjusted to vary their shock-
absorbing abilities.
● This adjustment is achieved using technologies like
special fluids or electromagnetic dampers, enabling
dynamic control of damping forces in response to
changing road conditions and driving scenarios.
● These semi-active dampers adapt to the vehicle's
suspension requirements, striking a balance between
comfort and performance by providing variable shock
absorption as needed, resulting in a smoother and
more controlled ride.

6. 3. Active Suspension System
● An active suspension system, also known as an active or
adaptive suspension system, is a kind of car technology.
● Its job is to make the ride more comfortable, stable, and easy
to control by adjusting the suspension based on how you're
driving and the conditions of the road.
● Unlike regular suspension systems that have fixed parts like
springs and dampers, an active suspension system uses
sensors, parts that move, and computer programs to control
and change the suspension in real time.

7. Objectives:
1. To design a semi-adaptive suspension system that can electronically adjust damping
forces in response to varying road conditions and vehicle dynamics.
2. Quantitative Analysis including mathematical modeling and simulations, to assess the
performance and effectiveness of the semi-adaptive suspension system.
3. To enhance Vehicle Stability by proactively adjusting damping rates.
4. Focus on improving safety by ensuring the semi-adaptive suspension system can
respond effectively to sudden changes in road conditions.
5. To extend vehicle component lifespan by minimizing wear and tear caused by
vibrations and shocks.

8. Literature Review
1.Seiyed Hamid Zareh's Paper: Focuses on improving passenger car suspension by
integrating Magnetorheological (MR) dampers. These dampers adjust their
viscosity with changes in a magnetic field, effectively reducing vibrations from road
irregularities.
2.Prashant Narwade's Paper: Uses computer simulations to compare traditional
Macpherson strut suspensions with semi-active suspensions using MR dampers
and PID controllers. The results show that PID-controlled semi-active suspensions
significantly enhance ride comfort and vehicle stability, quickly adapting to bumpy
roads. This research paves the way for advancements in vehicle suspension
technology.

9. Literature Review
3. R. Rajamani, Vehicle Dynamics and Control, Mechanical Engineering
Series
According to this book, the semi active suspension model consists of a
twin tube variable orifice damper in which the orifice diameter can be
varied with electronic control. As the piston moves inside the cylinder, it
causes fluid flow through the orifice. A larger orifice provides less
dissipative resistance while a smaller orifice provides increased
dissipative resistance. To use the variable orifice damper as a semi-active
actuator, the opening of the orifice is determined in real time by
feedback control laws. Thus the damping provided by the device is varied
in real time by feedback control.

10. Methodology
1. Formulation of mathematical model of semi active
suspension system
2. Determine the design constraints and parameters
involved
3. Formulation and simulation of simulink model based
on MATLAB
4. Observation and analysis of results obtained
5. Multiple iteration to optimize our model

11. List of tasks

12. Gantt Chart

13. Conclusion
In conclusion,Vehicle suspension systems have evolved significantly over the years, from
simple leaf springs to sophisticated adaptive systems. These advancements have
improved vehicle handling, ride comfort, and safety.
So our project is based on qualitative analysis, mathematical modeling, and iterative
simulation of semi active suspension, we will not only demonstrate the feasibility of our
semi- active suspension but also fine tune the performance of suspension as much we
can.

14. References
1. Zareh, S. H., Sarrafan, A., Khayyat, A. A. A., & Zabihollah, A. (2012). Intelligent semi-
active vibration control of eleven degrees of freedom suspension system using
magnetorheological dampers. Journal of Mechanical Science and Technology, 26(2),
323-334.
2. Narwade, P., et al. (2020). Modeling and Simulation of a Semi-active Vehicle Suspension
System using PID Controller. IOP Conference Series: Materials Science and Engineering,
1004, 012003.
3. R. Rajamani. (2012). Vehicle Dynamics and Control (Mechanical Engineering Series). DOI:
10.1007/978-1-4614-1433-9_1. Springer.

15. THANK YOU

16. Any Queries?