getting started using adams/controls - md adams 2010
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DESCRIPTIONThis is getting started guide for Adams/Controls - MD Adams 2010 version.
Getting Started Using Adams/Controls Introducing and Starting the Tutorials Learning Adams/Controls with MATLAB Co-Simulation/Function Evaluation Learning Adams/Controls with Control System Import from MATLAB Learning Adams/Controls with Control System Import from MATLAB with S-Functions Learning Adams/Controls with Easy5 Co-Simulation/Function Evaluation Learning Adams/Controls with Control System Import from Easy5
2 Getting Started Using Adams/Controls
Introducing and Starting the Tutorials
Introducing and Starting the Tutorials 3Overview
OverviewThis chapter starts you off on the process of adding controls to your Adams model. Following this chapter are tutorials for some of the controls applications you can use with Adams/Controls: co-simulation and Control System Import with Easy5 or MATLAB. After you finish this chapter, continue with the tutorial that is specific to the controls application you are using. This chapter contains the following sections: About the Tutorial How Youll Learn Adams/Controls Starting Adams/View Step One - Build the Adams Model Step Two - Creating the Adams Plant Inputs and Outputs
Before doing these tutorials, you should be familiar with the basic features of the Adams/View interface. Refer to the online help for Adams/View for information about the Adams/View interface. This tutorial takes about two hours to complete.
4 Getting Started Using Adams/ControlsAbout the Tutorial
About the TutorialThe tutorials in this guide give you an overview of the four-step process of adding controls to an Adams model. See Welcome to Adams/Controls > About the Adams/Controls Four-Step Process in Adams/Controls online help, for a description of the four-step process. This chapter covers Steps One and Two of the process in depth. You'll learn how to: Import an Adams model and run a trial simulation with Adams/View. Use the Adams/Controls interface to identify the inputs and outputs from your Adams model,
and create the files for the plant model in Easy5 and MATLAB/Simulink. Steps Three and Four are covered in the chapters that follow for each controls application.
Introducing and Starting the Tutorials 5How Youll Learn Adams/Controls
How Youll Learn Adams/ControlsBy following the tutorials in this guide, youll apply the four-step process of using Adams/Controls on a simple antenna-pointing problem. The objective of the problem is to add a control system to the antenna that will move the antenna along a defined path to track a satellite signal. For this tutorial, you will supply the torque that pivots the antenna in the azimuthal (horizontal) direction. The torque level will be computed by a control system, based on the error between the actual antenna position and the desired antenna position. This is more realistic than attaching an Adams motion to the pivot and driving the motion directly. By applying a torque, you can look at issues related to motor size in an actual mechanical system.
6 Getting Started Using Adams/ControlsStarting Adams/View
Starting Adams/ViewIn this section, you learn how to create a new directory and start Adams/Controls from within Adams/View in the UNIX and Windows environments. In the UNIX environment, you start Adams/View from the Adams Toolbar, and then, from within Adams/View, you load the Adams/Controls plugin. For information on the Adams Toolbar, see the online help for Running and Configuring Adams. In the Windows environment, you start Adams/View from the Start menu, and then load the Adams/Controls plugin. For more information, see the online help for Running and Configuring Adams. To start Adams/View: 1. Copy all of the files in install_dir/controls/examples/antenna to a new directory. 2. Do either of the following depending on the platform on which you are running Adams/View: In UNIX, type the command to start the Adams Toolbar at the command prompt, and then
press Enter. Select the Adams/View tool
In 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.
Introducing and Starting the Tutorials 7Step One - Build the Adams Model
Step One - Build the Adams ModelNow youll import an Adams model and familiarize yourself with its construction by following the next four sections: Build the Adams Model Loading Adams/Controls Familiarizing Yourself with the Model Running a Trial Simulation
Build the Adams Model1. Select Import a File. 2. In the Start In text box on the Adams/View welcome screen, enter the name of your new directory (the one created in Step 1. in To start Adams/View: above). This sets your new directory as your working directory. 3. Select OK to close the Adams/View welcome screen. 4. In the File Import dialog box, right-click the File to Read text box, and then select Browse. The File Selection dialog box appears. 5. Select the file antenna.cmd. 6. Select OK. The antenna model main_olt appears as shown in Figure 1. 7. To change the display of the antenna from a wire frame into a shaded, three-dimensional image, from the Main toolbox, select Render.
Plate Reduction gear
8 Getting Started Using Adams/ControlsStep One - Build the Adams Model
Shaded Model of Antenna
Loading Adams/ControlsBecause Adams/Controls is a plugin for Adams/View, you need to load Adams/Controls when you use it with Adams/View. To load Adams/Controls: 1. From the Tools menu, point to Plugin Manager. 2. Select the Load checkbox next to Adams/Controls. 3. Select OK. Adams/View loads the Adams/Controls plugin. Notice that there is now a Controls menu on the main menu. Note: To automatically load Adams/Controls each time Adams/View starts up, select Load at Startup in the Plugin Manager.
Familiarizing Yourself with the ModelThis model is designed so that its base turns in the azimuthal (horizontal) direction and its antenna tilts in the vertical direction. To familiarize yourself with the model, locate the following components: Azimuth rotor (peach) connected to ground by revolute joint. Azimuth reduction gear (sky blue) connected to ground by revolute joint. Azimuth plate (magenta) connected to ground by revolute joint. Antenna support (silver) connected to plate by fixed joint. Elevation bearings (peach) connected to support by fixed joint. Antenna (sky blue) connected to bearings by revolute joint. rotor_gear, couples the revolute joint at the rotor to the revolute joint at the reduction gear. gear_plate, couples the revolute joint at the reduction gear to the revolute joint at the plate.
Running a Trial SimulationTo run a trial simulation with Adams/View: 1. From the Simulate menu, select Interactive Controls. 2. Enter the following in the Simulation Controls dialog box: End Time: 0.5
Introducing and Starting the Tutorials 9Step One - Build the Adams Model
3. Select Start at equilibrium. 4. Select the Start tool . The base of the mechanism turns counterclockwise as the antenna tilts up and down.
Deactivating the MotionNow that you know the model is working properly, you can begin the process of adding a control system to it. The first step is to deactivate the azimuthal motion on the model. After the motion has been deactivated, you will apply a torque to the joint .main_olt.azimuth_actuator based on values that the controls system package provides. To deactivate the motion: 1. From the Edit menu, select Deactivate. The Database Navigator appears. 2. Double-click the model main_olt. A list of parts and motions appears. 3. Scroll down the list and select azimuth_motion_csd. 4. Select OK. Adams/View deactivates the motion. 5. Select the Reset to Start tool 6. Rerun the simulation. Now that youve deactivated the azimuthal motion, the antenna moves up and down, but it does not sweep horizontally as it did during the last simulation. Note: You might detect some small movement in the azimuthal direction because the model has no constraints or restoring forces to control its natural movement. You should also notice that the bending of the antenna support beam decreases when the azimuthal motion is deactivated. The flexing illustrates that a certain amount of coupling takes place between the elevation and azimuthal movements. to reset the simulation back to its first frame.
10 Getting Started Using Adams/Controls
Step Two - Creating the Adams Plant Inputs and Outputs
Step Two - Creating the Adams Plant Inputs and OutputsNow youll create the inputs and outputs on the Adams model by: Identifying the Adams Plant Inputs and Outputs Verifying Input Variables Verifying Input Functions Verifying Output Functions Exporting the Adams Plant Files for the Controls Application
Identifying the Adams Plant Inputs and OutputsFigure 2 indicates the flow path of the input and output variables shared between the antenna model and its control system. This diagram shows that when you supply an input control torque to the antenna model, you send outputs azimuth_position and rotor_velocity to the controller.
The steps you follow to achieve this closed-loop circuit are: Define the input and output variables in Adams/View. Read in the plant and the input/output variables using Easy5 or MATLAB, create an Adams
plant, and run a simulation. Animate and plot the simulation results in Adams/View. Modify the variables and repeat this process as necessary.
Input = control _torque
Adams model Control system
Output = azimuth_position and rotor_velocity
Terminology for Adams Inputs and Outputs