using adams/controls - md adams 2010

Download Using Adams/Controls - MD Adams 2010

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Welcome to Adams/Controls 1

Welcome to Adams/Controls

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About Adams/Controls

About Adams/ControlsAdams/Controls, part of the MD Adams 2010 suite of software, is a plugin to MSC.Softwares Adams/Car, Adams/Chassis, Adams/View, or Adams/Solver that helps you add sophisticated controls to your Adams model. Adams/Controls lets you connect your Adams model to block diagrams that you've developed with control applications such as Easy5 or MATLAB.

Welcome to Adams/Controls 3Benefits of Adams/Controls

Benefits of Adams/ControlsBy combining mechanical system simulation tools and controls design tools, you can: Add sophisticated controls to an Adams model and simulate the combined system. Generate mechanical system simulation models directly from your Adams data without having

to write equations. Analyze the results of your simulation in the Adams environment or the controls application


How to Improve the Design Process with Adams/ControlsIn the typical design process of a mechanical system with controls, the mechanical designer and the controls designer work from the same concept, but use different sets of software tools. The result is that each designer produces a model for the same problem. Each design is then subject to verification and testing, and the first time the two designs are brought together is during physical prototype testing. If a problem occurs during the interaction between the controls design and the mechanical design, the engineers must refine the control design, the mechanical design, or both, and then go through the entire verification process again as shown in the figure below.

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Benefits of Adams/Controls

With Adams/Controls, the two designers can share the same mechanical model. They can also verify from one database the combined effects of a control system on a nonlinear, non-rigid model. The physical testing process is greatly simplified, and the risk of the control law being poorly matched to the real system is eliminated as you can see in the figure below.

Welcome to Adams/Controls 5Ways to Use Adams/Controls

Ways to Use Adams/ControlsYou can use Adams/Controls in the a variety of ways. Adams/Controls offers you the option of simulating the combined mechanical system and controller: entirely within the controls application via Function Evaluation. entirely within Adams via Control System Import. by solving the controls equations with the control package and solving the mechanical system

equations with Adams via co-simulation. Using co-simulation or Function Evaluation: By using Adams/Controls with Adams/View, you can animate your model and view the effects of the control system and any structural modifications you make. For faster simulation results, you can run Adams/Controls directly with Adams/Solver, MSC.Softwares powerful analysis engine. The process is faster because you're running a simulation in batch mode. You can also run Adams/Controls with Adams template-based products, such as Adams/Car, and others. In these environments, you run the simulations in batch mode and view model animations when the simulation is complete. Adams/Car also requires co-simulation mode to run. Using Control System Import: You also have the option with Adams/Controls to import the controls system definition into Adams. Importing the control system requires either Mathwork's Real-Time Workshop or Easy5's XFE.

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About the Adams/Controls Four-Step Process

About the Adams/Controls Four-Step ProcessThe figure below describes the four-step process of combining controls with a mechanical system. Refer to Getting Started Using Adams/Controls for detailed procedures for each step.

Adams Input


Adams Output

Controls Input

Controls Application

Controls Output

1. Build the Model - The first step in working with Adams/Controls is to build or import an Adams model. The model should be complete and include all necessary geometry, constraints, forces, and measures. 2. Create the Adams Inputs and Outputs - The outputs describe the variables that go to the controls application (the output from the Adams model is the input to the controls system). The inputs describe the variables that come back into Adams (the output of the controls application) and, therefore, complete a closed loop between Adams and the controls application. All inputs and outputs must be set up as state variables. After these are defined, you export the plant system files from Adams for use in the controls simulation software. 3. Build the Block Diagram - Build the control system block diagram with Easy5 or MATLAB/Simulink. Include the Adams plant in your block diagram, or if using Real-Time Workshop, export the controls system and import into Adams. 4. Simulate the Model - Simulate the combined mechanical model and control system. Several different methods are available to run your simulation.

Adams/Controls Overview 7

Adams/Controls Overview

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Loading Adams/Controls

Loading Adams/ControlsTo start Adams/Controls, you first start your host product, such as Adams/View, import a model, and then load the Adams/Controls plugin. To start Adams/Controls: 1. Start Adams/View by doing one of the following: On UNIX, type the command to start the Adams Toolbar at the command prompt, and then

press Enter. Select the Adams/View tool. On Windows, from the Start menu, point to Programs, point to MSC.Software, point to MD

Adams 2010, point to AView, and then select Adams - View. The Welcome dialog box appears, in the Adams/View main window. 2. From the Welcome dialog box, select Import a file, and then select OK. 3. Select the file you want to import. 4. In the Select File dialog box, select OK. 5. In the File Import dialog box, select OK. The model appears in the Adams/View main window. 6. Load Adams/Controls by doing the following: From the Tools menu, point to Plugin Manager. Select the Load check box next to Adams/Controls. Select OK.

Adams/Controls is now loaded. To unload the Adams/Controls plugin: 1. From the Tools menu, point to Plugin Manager. 2. Clear the Load check box next to Adams/Controls. 3. Select OK.

Adams/Controls Overview 9Getting Started Using Adams/Controls

Getting Started Using Adams/ControlsWhen first starting using Adams/Controls, we recommend that you start by working through the tutorial entitled 'Getting Started Using Adams/Controls'. This tutorial gives you an overview of the four-step process of adding controls to an Adams model. The example also includes tutorials for each of the controls applications you can use with Adams/Controls: Co-simulation, Function evaluation, and Control System Import with both Easy5 and MATLAB. See the Examples section to find this tutorial.

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Simulation Methods

Simulation MethodsChoosing a Simulation Method Adams/Controls offers you three methods with which you can simulate your integrated model and controller:Co-simulation/Discrete mode: Specifies that Adams solve the mechanical system equations and the control application solve the control system equations. The mode names of "co-simulation" and "discrete" are synonymous. Function Evaluation/Continuous mode: Specifies that the control application solve both the mechanical and control system equations. The mode names of "function evaluation" and continuous are synonymous. Control System Import : Specifies that Adams solve the combined mechanical system and control system

equations by importing an External System Library (ESL) which is generated by MATLAB/Real-Time Workshop or Easy5. The ESL is used by automatically creating a General State Equations (GSE) entity in Adams. This process is also known as External Function Evaluation (XFE), External System Import (ESI), Importing General State Equations, or Dynamic System Import (DSI). These methods allow you to use different methods to integrate your Adams and controls models (EASY5 or MATLAB). See the table below for an overview of suitable controller/simulation method options. Simulation Method Controller type: Continuous Continuous sampled controller Controller with discrete and continuous states Discrete mode: Continuous mode: C-code import: Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes No

Discrete controller with synchronous Yes sampling rates Discrete controller with asynchronous multi-sampling rates Logic-based controller Co-simulation No No

For most analyses, the discrete mode is generally the more efficient simulation method. It is faster and can handle complex models better than continuous mode. You should use continuous mode when equations solved in the control system would cause a large coupling effect on the Adams data. For example, you might prefer to use the continuous mode if your analysis requires a very small time step.

Adams/Controls Overview 11Simulation Methods

To preserve the proper dynamics for a mechanical system, discrete mode should sample the mechanical system at least five times greater than the highest frequency of interest. If the time step is too small to sample at five times the highest frequency, then you should use continuous mode. Note:

You can find the highest frequency of your mechanical system by performing a linear analysis with the Adams add-on module, Adams/Linear.

Function Evaluation In continuous (function evaluation) mode, the control system package solves the equations of motion for the combined controls and mechanical dynamics system. Adams formulates the equations of motion for the mechanical subsystem and provides information to the controls package as needed. Typically Adams simulations involve solving