Note: This functionality is only available in AutoTURN and AutoTURN Pro.

The Reverse Corner Path tool allows a reverse maneuver to be generated with a tangent-arc-tangent combination by specifying the desired sweep angle (via keyboard entry or selecting drawing elements). The entrance and exit tangents can be lengthened or shortened by moving the mouse in the direction of the tangent.

Reverse Corner Path Dialog Box

Current SmartPath Tool

Highlights the current SmartPath Tool

Switch to Forward/Reverse

For forward maneuvers, the Switch to Reverse button changes the maneuver to a reverse maneuver.

For reverse maneuvers, the Switch to Forward button changes the maneuver to a forward maneuver.

Maneuver Type

Indicates which direction and what type of section (forward or reverse) is being generated for the selected SmartPath Tool.

Current Vehicle

Displays the current vehicle's library and name (see Vehicles -> Select Current Vehicle).

Steering Lock Angle or Reverse Overrides

Indicates whether the vehicle’s steering specifications or reverse overrides are being used while generating the simulation. When a forward simulation is being generated, the vehicle’s steering lock angle will always be used. When generating a reverse simulation, the Reverse Overrides settings (see Program Settings -> Vehicle Defaults Category: Reverse Overrides) will be used if they are greater than the steering specifications for the vehicle.

Preview Arc Path

If this checkbox is selected, the left and right projected swept path envelopes for an arc path simulation will display to help you preview the next section of the simulation. AutoTURN Pro calculates the projected swept path envelopes based on the minimum turning radius for the specified Speed value.

Speed

Sets the speed at which the vehicle is traveling.

Note:

• The speed value only affects the minimum turning radius, as opposed to the speed values indicated in the speed profile report which are the maximum speeds achievable at any given point of time (see Speed Profile Report).
• For forward maneuvers, the maximum allowed speed is 45 mph (70 km/h). Reverse maneuvers are conducted at 6 mph (10 km/h) or less.

Select one of the following radius types:

• Centerline - radius is measured to the middle of the front steering axle group
• Curb to Curb - radius is measured to the outside front tire track envelope
• Wall to Wall - radius is measured to the outside vehicle body envelope
• Inner Turn - radius is measured to the inside rear tire track envelope

The Radius value is displayed for this type.

Radius

An edit box is provided to set the desired radius value for the selected radius type.

Note: AutoTURN Pro will not allow a radius to be set to a smaller value than the minimum radius capabilities for the current vehicle at the current speed.

Sweep Angle

The sweep angle is defined as the angle between the direction of travel and the exit tangent (new heading). For corner path turn simulations (see Generate Corner Path), the centerline of the vehicle will eventually become parallel with the exit tangent if the exit tangent is long enough - the longer the exit tangent is, the closer to zero the steering angle becomes. For oversteer corner path turn simulations (see Oversteer Corner Path), the centerline of the vehicle is always parallel with the exit tangent. To set the sweep angle, type the desired value in the corresponding edit box or click the Select Sweep Angle button, and then pick an element in the drawing area.

Example of a sweep angle

Superelevation

Displays the superelevation (i.e. slope) of the road surface. This value is considered in determining the minimum turn radius, and is only available at speeds of 10 mph (16 km/h) or greater. Select the Set checkbox to override the default value.

Note: In the SmartPath Tools, superelevation is limited to the range of -0.1 to 0.1.

Lateral Friction

Displays the friction factor between the vehicle’s tires and the road surface. This value is considered in determining the minimum turn radius, and is only available at speeds of 10 mph (16 km/h) or greater. Select the Set checkbox to override the default value.

Shrink/Expand

Click Shrink to reduce the SmartPath Tools dialog box to its minimum size to increase the working space in the drawing area.

Click Expand to return the SmartPath Tools dialog box to its full size.

Undo

Deletes the last generated section.

Hint: Alternatively, an undo operation can be performed by clicking inside the wheelbase of the last vehicle position generated.

The Oversteer Corner Path tool automatically switches to the Reverse Corner Path tool when a reverse maneuver is initiated.

The Reverse Corner Path tool behaves differently for one and two/three part vehicles:

• Generating Reverse Corner Simulations with One Part Vehicles

It is possible to set the radius type, radius, and sweep angle when generating reverse simulations with one part vehicles. In addition, the entrance and exit tangents can always be lengthened or shortened.

• Generating Reverse Corner Simulations with Two/Three Part Vehicles

Only the sweep angle and tolerance settings are available when generating reverse simulations with two part vehicles, and only the sweep angle setting is available when generating reverse simulations with three part vehicles.

The tolerance setting aids maneuvering in close quarters by setting an articulating angle between the tractor and trailer at the end of the arc portion of the maneuver. By default, tolerance is set to the minimum value of 0.1 degrees, which does not affect the generation of the simulation. Increase the tolerance to decrease the amount of space required to complete a reverse corner section. An exit tangent is not generated when tolerance is set to a value greater than 5 degrees. The maximum tolerance angle is 45 degrees.