Path Follower Instruction Video

General questions on the SMAC, msmac3D and other Collision Simulation programs
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MSI
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Posts: 1691
Joined: Thu Jun 18, 2009 12:37 pm

Path Follower Instruction Video

Post by MSI »

PATH Follower Option :
  • New Instruction Video Created and new project will be included in the update Path Follower template
    • To Get the project created in the video:
      • Download the Path Follower Template ZIP file(80 megs)
      • Save to your computer,
      • Use the Restore Project function from 3D Graphics to restore the project,
      • Then view the various option outlined below and work along with the online videos
Here are quick links to specific places in the video for specific tasks:
Time on VideoLink to Topic on Video
@1:00Clone the project
@2:06Inputs for Path follower on inputs 402,403,404,405
@2:34Turn off the collision simulation to allow easy setup of impact configurations
@3:38Settings Dialog Options including:
------> turning On/Off the path to be followed by the path follower mode
@4:37Run 0 sec simulations to set up path discussion and discussion of inputs for path
@4:36------> Set path follower to vehicle initial position
@5:19------> Setting up the path variables (curvature and distance along path)
@5:37------> Clone the Template project to create a new one
@6:21------> Add/change the ground to the cloned project
@7:25------> Set initial path/vehicle positions
@8:00------> Set Path parameters
---------> for radius and distance along path
---------> Run a 0 sec simulation and look at path and edit the path
@10:00------> Set variables to follow the path
-----------> on 405 (probe length, PGain and Qgain variables for steer responses)
@12:07------> Check the steer, acceleration etc for the vehicle from chart icon/link
@12:25------> Changing the vehicle speed to 25 mph
@13:29------> Setting option to use 3 points on probe/wagon tongue (at 75%,100%, 125%)
@14:06------> Direct comparison of 3Pt v 1 Pt wagon tongue steer
@14:24------> Collision Interaction OFF Option
-----------> benefits to set up impact and then turning the collision interaction back on
@15:32------> Use of steer table type 2 to insures path follower ends at collision detection
@16:38------> Determining the time of impact from output files
@17:04------> Using Tracking View for pan/zoom on the crash sequence
@17:29Recap of steps for Path Follower
@17:29------> Change the vehicle model/graphics specifications
------------> (just click on the vehicle and menus to right!)
@18:44------> Change the vehicle color
@20:27------> View the output files of VehicleSteer01.txt and/or VehicleSteer02.txt
-----------> automatically created when path follower used
----------->so you also can insert directly as inputs and delete the path following inputs
  • Fast easy way to get a vehicle to follow a roadway, make a corner, make a lane change
    • We recommend using path follower/driver model to determine steer required and then manually input the steer
    • We now automatically create the inputs so you can remove the driver model path follower and simply have steer you can then adjust
for additional information, please also see:
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Question? Comment? Please email us (all communications considered confidential)
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MSI
Site Admin
Posts: 1691
Joined: Thu Jun 18, 2009 12:37 pm

Re: New Path Follower Instruction Video

Post by MSI »

The path follower uses a 'wagon tongue' steer
  • A 'Wagon tongue' is a projection along the longitudinal axis ahead of the vehicle
  • We recommend starting with a length of 75% of the distance the vehicle travels in 1 sec (forward speed in inches per second * .75)
  • Then adjusting the length for more or less response
  • Also dependent on the PGain (error correction) and Qgain (damping) factors
We have added an option to use 3 points along the wagon tongue
  • They are set at 75%, 100% and 125% of the 'wagon tongue' length
  • The steer response then reflects a weighted average of the erros at the 3 lenght which provides for a smoother transition
Here is an example of the differences in the stter response during the path following
This is included in the above referenced instructional video
3 pt v 1 pt path following.png
3 pt v 1 pt path following.png (53.75 KiB) Viewed 156 times
NEW!! LEASE pricing of msmac3D Software!!
FOR MORE TOPICS see:Forum Index & McHenrySoftware.com
Question? Comment? Please email us (all communications considered confidential)
(c)McHenry Software, Inc ALL Rights Reserved.
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