Secondary steering includes both linked steering and manually controlled secondary steering. Secondary steering can consist of a linkage with manual override, or just manual control of a second set of steered wheels.
Linkage rules can apply in both directions at all speeds, or you can define rules that only apply in one or other direction from certain speeds and/or angles. Select The {Position} Axles Are Linked to specify axles whose angle is controlled by a linkage to an articulation or wheel angle. The linkage ratio is then the ratio of the secondary wheel angle to the controlling wheel angle. If this option is cleared, then the axles are set as manually controlled. Secondary steering must be either a linkage axle or a manually controlled axle.
Select the Scope of the linkage from the menu as Forwards Only, Reverse Only, or Forwards & Reverse.
Enter the Angle from which the linkage applies. Note that the first entry in the table always has a starting angle of 0.0, which cannot be edited. If you have an angular linkage that starts from a greater angle, click New to add a new linkage.
The Basis determines whether a factor is applied directly to the angles (the linked angle is directly proportional to the angle of the item to which it is linked) or to the tangents of the angles (the tangent of the linked angle is proportional to tangent of the angle of the item to which it is linked) or whether the linkage is defined as an effective wheelbase. Select Angles, Tangents or EWB as appropriate.
For linkages by Angles or Tangents, enter the linkage Factor, which is the amount by which the linked wheels turn expressed as a proportion of the angle of the item to which it is linked. The linkage factor is assumed to vary linearly to the next specified angle. The linkage factor does not increase beyond that assigned to the highest angle listed.
For linkages by effective wheelbase (EWB), enter the EWB as the distance from the effective steered axle to the effective fixed axle. The EWB is assumed to vary linearly to the next specified angle. The EWB does not increase beyond that assigned to the highest angle listed.
If there are speed dependent linkages, select These Linkages Are Also Speed Dependent, and select the Scope of the speed related linkage: Forwards Only, Reverse Only, or Forwards & Reverse.
Enter the Speed from which the linkage applies. Note that the first entry in the table always has a starting speed of 0.0, which cannot be edited. If you have a speed linkage that starts from a higher speed, click New to add a new linkage.
Enter the speed linkage Factor, which is the amount by which the linked wheels turn expressed as a proportion of the angle of the item to which it is linked. The linkage factor is assumed to vary linearly to the next specified speed. The linkage factor does not increase beyond that assigned to the highest speed listed. If you have a speed linkage that starts from a greater speed click New to add a new speed linkage.
If the linkage ratio can be controlled by the driver, select This Linkage Can Be Overridden At Drive Time. Select Forwards if the linkage ratio can adjusted while travelling forwards, and Reverse if it can be adjusted while reversing. If there is a limiting speed in either direction, select Below Speed Of and enter the limiting speed.
Finally, enter the range within which the linkage ratio can vary. Note that this is always expressed as the ratio between the limiting angles of the linked wheels and the angles of the item to which they are linked (typically the articulation angle), so the minimum ratio will give the greatest off-tracking and the maximum ratio the smallest off-tracking.
Select The {Position} Axles Can Be Manually Controlled to specify wheels whose angle can be set independently of the primary steered axles. If this option is cleared, then the axles will be set as linked. Secondary steering must be either a linkage axle or a manually controlled axle.
The maximum secondary steering angle is the maximum angle of any wheel in the secondary steered axle group.
By default the secondary lock-to-lock time is zero, meaning that there is no delay in the application of changes in the secondary steering angle. However, we recommend that a value be entered if known.