Road-Profile Setup: ARIDE_FOUR_POST_TESTRIG
Ride -> Full-Vehicle Analysis -> Four-Post Test Rig -> Set Up Road Profiles
Sets up the road profile (See Road-Profile Generation Tool).
For the option: | Do the following: |
|---|---|
Profile Source | Select one of the following: ■RPC files - Allows you to use road-profile data stored in the RPC III file format to drive the four-post test-rig actuators in displacement. Such data could be measured (for example, from a profilometer) or generated from a mathematical model for road roughness. In particular, Ride -> Tools -> Road-Profile Generation displays a dialog box for such a mathematical model. The data generated is stored in the RPC III format. Therefore, you can use that tool to generate data to select from the current dialog box. Learn about RPC III Format. ■sum RPC files & table functions - Takes the height road-profile data from both sources and sums it together as the input to the actuators. Therefore, is useful if you want to superimpose a bump on top of a road profile. For example, you might represent the overall road with data from RPC files, but then create a bump with a table function. ■table functions - Allows you to drive the actuators in displacement using a table function whose data is stored in a TeimOrbit file (see TeimOrbit File Format). You can create and edit such tables with the Curve Manager. (For Beta, we recommend that you use the example table-function data file as templates to create your own data by directly editing the files, instead of the Curve Manager.) See Curve Manager. |
Input per Wheel | By default the user needs supply a road profile for the left and right tires. Note that such a profile contains road height data as function of travelled distance. In case input per wheel is selected, a road profile containing road height data as function of time can be selected as input for each wheel. |
Vehicle Speed | Select the forward speed of travel for the vehicle. Note that negative values are not allowed. The vehicle does not travel down a road with the four-post test rig: the wheels do not spin and the mass-center velocity hovers around zero. However, the vertical-height inputs to the rear wheels lag behind those of the front wheels by (Calculated Time Lag) = (Calculated Wheelbase)/(Vehicle Speed). Therefore, the test rig cam approximates a road very well. |
Calculated Wheelbase | Displays the calculated wheelbase. The wheelbase is derived from the locations of the spindle-centers in the vehicle assembly. It is the average of the for-aft distance for the left and right side of the vehicle, evaluated in the design configuration (not in the static-equilibrium configuration). |
Calculated Time Lag | Displays the time that inputs to the rear wheels lag behind those of the front. It is calculated as explained for Vehicle Speed. |
If you set Profile Source to RPC files, Adams Car Ride displays the following options: | |
RPC Files With Road Profiles - Left Wheeltrack Profile/Right Wheeltrack Profile | |
File Name | Select the full path to an RPC III file with road-profile data. If you right-click and Search the <aride_shared> database, you will see at least two RPC III files in the "road_profiles.tbl" directory: "example.rsp" and "flat.rsp". Note that .rsp is the extension that denotes RPC files. Use flat.rsp if you want zero vertical input to one (or both) sides of the vehicle. Both the left and right wheeltracks can refer to the same RPC file, but they can also refer to different files. Note: If 'Input per Wheel' has been selected, the RPC III file should contain road height data as function of time; if 'Input per Wheel' is not selected the RPC III file is supposed to contain data as function of travelled distance. |
Channel Number | Enter the number of the channel that has the data you want to use. Data is stored in RPC III files by channel. Each channel is referenced by its number. Both the left and right wheeltracks can use the same channel from the same file, different channels from the same file, or the same channel or different channels (numbers) from different files. You can give the vehicle symmetric inputs if you use the same channel number from the same file for both wheeltracks. Note that the Adams Car Ride Road-Profile Generation tool always uses channel 1 for the left wheeltrack and channel 2 for the right wheeltrack. |
Channel Scale | Scales the road height input with this scaling factor, default 1.0. |
If you set Profile Source to sum RPC files & table functions or to table functions, Adams Car Ride displays the following options: | |
Table-Function Property Files With Road Profiles - Left Wheeltrack Profile/Right Wheeltrack Profile | |
File Name | Select the full path to a TeimOrbit text file with road-profile data. If you right-click and Search the <aride_shared> database, you will see at least two RPC III files in the "road_profiles.tbl" directory: "bump_1inch.rpt" and "flat.rpt". Note that .rpt is the extension that denotes TeimOrbit road-profile data files.). Use flat.rpt if you want zero vertical input to one (or both) sides of the vehicle. Both the left and right wheeltracks can refer to the same TeimOrbit file, but they can also refer to different files. You can give the vehicle symmetric inputs if you use the same file for both wheeltracks. Note: If 'Input per Wheel' has been selected, the table file should contain road height data as function of time; if 'Input per Wheel' is not selected the table file is supposed to contain data as function of travelled distance. |
 | Select to display the Data Editor/Viewer to plot the wheeltrack profile. |