Adams

MSC.Software VPD Conference | July 17-19, 2006 | Huntington Beach, California

Virtual Prototyping of an Active Suspension Using Adams/View® and Matlab®

M.Sc. Aline DrivetMonterrey Institute of Technology (ITESM)

Monterrey, Mexico

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Abstract

• Title: Virtual Prototyping of an Active Suspension Using Adams/View® and Matlab®

• Presentation Reference Number: 2006-71• Authors: M.Sc.Aline Drivet, Phd. Ricardo Ramírez-Mendoza

Mechatronics Department, Monterrey Institute of Technology, ITESM.Ave. Eugenio Garza Sada Sur nº 2501 Col. Tecnológico, MTY. N.L. México

Tel:52(818)3 58 20 00Email :{ ricardo.ramirez, drivet} @itesm.mx

Abstract: Present the work done to model a passive front suspension of a car in Adams/View; the methodology to include actuators and controllers using a mathematicalsolver such as Matlab®. Some preliminary results are included, such as validation of themodel and the results obtained after including different types of controls.

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• Outline:Introduction: Some general issues on modeling and simulation.Objective and MaterialsModeling a SuspensionUse of realistic actuatorsPreliminary results using active suspensionConclusionsQuestions

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Center for Innovation on Design and TechnologyMechatronics and Automation Area

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DISTANCE IN MILES:

GUADALAJARA, JAL. 481

PHILADELPHIA, PA.1,776

SAN FRANCISCO, CA1,653

DALLAS, TX.567

MEXICO, DF 618

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Introduction:• It is more convenient for a manufacturer of cars, airplanes or any other

vehicle to create accurate designs before producing a prototype, saving both time and money.

• One solution is using software to simulate and test a model before going into production.

• The principal reason is financial.• It is a lot cheaper try an idea in a PC than implement it.

• It is very expensive to make a prototype.

• It is cheaper and faster to create a digital prototype.

• There are some things that can not be digitally tested, these have to be done with an actual prototype.

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We need a PC to solve simulation problemsWe know the math solution, such as differential equations (DE’s), homogeny solutions

and particulars, numerical methods, FEM, etc.But in reality, simulation requires more complicated equations :

4 Steps for a good Simulation• First : modeling of physical system

• Usually used in ordinary, partial differential equations, etc.• Second : Introduce the desired model form into a simulation software

• Different ‘Syntax’ for different software.• Third : Simulate the system using an appropriate numeric integration.

• fast system? lineal system? • Fourth : analyze the results

• Are they reasonable?, What are the outputs of each scenario?

0)0( ; xtxaxx ===&

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• Objective:

To obtain a computer model of a Renault Scenic’s suspension for active control purposes• Visual Inspection• Data acquisition• Physical measures

• Methodology:1. Modeling the car2. Validating the model3. Preliminary Tests

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• Materials:1. Renault Scenic 2.1liter 16v (2001)2. MTS 810 Material Testing System3. MSC Adams 2005

• Adams/View• Adams/Car• Adams/Controls

4. MATLAB 75. Cad Software

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1. Suspension ModelingProceed to disarm the suspension, and take precise measurements.(if possible use sophisticated coordinate machine)

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Draw all the pieces in a CAD software to obtain Inertias, weight andother relevant data.

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Obtain damper and spring characteristics through testing.

STRUT2 F-xy = 0.0279x - 3.9041R2 = 0.9056

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Despl (mm)

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Model in Adams/View:1 - Establish all space coordinates of the joints.2 – Establish type of joints and characteristics (bushings)3 – Build the model in Adams with the inertias, weight and

properties obtained previously.

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• Use Non linear Characteristics for Spring and Damper.

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2. Validating the model: frequency response analysis and Time response

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• Why introduce mathematical Solver software?• There are many models of controllers already in this type of

software.• There are many models for actuator already in this type of

software. For example: MR DAMPER (Bouc-Wen)

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• Why introduce mathematical Solver software? • Use realistic actuators. Bouc Wen Model of MR damper.

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• Why introduce mathematical Solver software? • Use realistic actuators. Bouc Wen Model of MR damper.

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Use sophisticated Controllers in real time simulations. Skyhook,Hinf, etc…

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3. Preliminary results: Chassis displacement of open and closeloop.

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• CONCLUSIONS:

• Development of models and simulation, reduce cost and time.• Commercial software simplifies the Virtual Product Development

process re: model creation and data entry.• Must be careful to analyze signal/noise; useful signals. Garbage in

=> Garbage out.• We must have a “good feeling” on the physical relationships of

the model. Do not believe all simulation results!• Analytical models are very useful to understand the vehicle

dynamics. Consider sub-models of the complex vehicle dynamics.

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