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Swept Path Analysis

Use this dialog to construct swept path curves for various vehicles, both standard vehicles according to N100 and user-defined vehicles.

Where do I find the dialog?

On the Planning, design and execution toolbox in terrain model drawing, select the icon Swept path analysis...

Overview

Tracking creates a command, Swept path curves(), in the command list. The command is dynamic, meaning you can change the parameters and the swept path curves are updated immediately.

You can have multiple commands in the same drawing and they show the swept path curves and vehicles in plan and in 3D.

We can also draw 3D lines for bottom load and bottom body (outer boundary lines). These can be used to check if they collide with roadway, rock cuts, 3D objects, etc.

Note

We can copy these 3D lines to an application layer, or to extra lines for display in cross sections. Use the command to copy from command list to application layer. Remember to leave the result application layer field blank if the intention is to paste the lines into the extra lines dialog.

Create a new swept path curve

Procedure

  1. Select the Swept path analysis... function on the toolbox
  2. Select Vehicle in the dropdown menu
  3. Select swept path curve(s) to be drawn: Body, Wheels and/or Load
  4. Check placement of vehicle on the line: start point, end point and/or arbitrary point
  5. Click OK to start inserting points for the curve
  6. Point and click first point
  7. Point and click second point
    Hold down the [Shift] key before placing the point if we want a straight line to the second point
  8. Press [Enter] when the points are placed

Tip

With the Follow roadway option when inserting new points, the center of the roadway is snapped when inserting points within the roadway's extent. The exception is for narrow roads (or roads where the vehicle is wider than the roadway), where new points are snapped to the center line.

Using active steering

We can enter rear steering angle manually (procedure described below) or have the program do this automatically for vehicles with active steering on the rear axle (the maximum rear steering angle must also be entered on the element). With automatic active steering, the program will make the rear axle follow the driving line as far as possible.

Procedure

  1. Create new swept path curve for the vehicle
  2. Open the property dialog again and the Rear steering angle field is active
  3. Select profile number, for example by clicking the Forward button, and enter value for steering angle. You can use the + and - buttons to increase or decrease the steering angle. You enter the desired increment value yourself. Alternatively, you can enter a value and click Update
  4. Repeat step 3 for all relevant profile numbers along the road line. Between specified angles, the values are interpolated
  5. The list of profile numbers with corresponding steering angles can be found in the Active steering tab

Edit existing swept path curve

Procedure

  1. Select the swept path curve on the map
  2. Point to black grip point to move corner point
  3. Point to white grip point to insert corner point
  4. Press [Enter] when the point(s) are placed/edited

View details on driving route

Procedure

  1. Open the Swept path curves command
  2. Check Show vehicle in profile
  3. Set desired interval (how much you should move for each click)
  4. Move forward with the Forward button and backward with the Backward button

Steering type

When specifying steering type Active on the rear axle, we can specify the steering angle in two different ways:

Direct angle

Kingpin angle percentage

Percentage angle of rear axle steering relative to the trailer's rotation around the king pin. When specifying Follow, there is always 100% angling of the rear axle group.

Between the points we specify, the angle changes linearly.

Reversing

The program handles reversing for vehicles with up to two elements (semi-trailer).

Warning

There is no support for steering type Active and Follow for vehicles with two elements.

When you place the points for the driving line, the vehicle hangs on the front axle. When you construct the section for reversing, the point is moved to the rear axle. In other words, the program automatically figures out where there is reversing (thick blue line) by considering changes in the driving line.

Example: Turning hammer

The example below shows how we enter the line in a turning hammer (reversing highlighted).

User-defined vehicles

The vehicle editor is found under Common settings in the Gemini Terrain Settings... dialog on the toolbar. Here we can, among other things, define our own vehicles.