OverTilt is RTI's Motion Drive Algorithm
(MDA), designed to generate an optimal set of motion
cues while keeping the motion system within its physical
limits. We use a tuning file to select the parameters
for the MDA.
OverTilt® provides an advanced form of tilt
coordination. It fully coordinates the linear and
angular movement of the motion base, providing optimum
specific force cues, and high frequency and sustained
specific force cues.
Using OverTilt , we’ve achieved "adaptive" type
algorithm performance without running into complex
tuning requirements or the instabilities you usually
encounter when using such algorithms.
The OverTilt algorithm can be quickly configured for a
variety of motion bases, both large and small. For
linear specific force, only three parameters must be
configured: maximum specific force, maximum
position and maximum tilt rate.
OverTilt performs motion base
pre-positioning as determined by the current input
acceleration. It also provides smooth adjustments in the
commanded specific force, avoiding large false cues
which can occur when the motion base reaches its
A Classical Mode, which RTI’s MDA also includes, filters
the three channels of angular velocity and three
channels of specific force using a set of six 2 pole, 2
zero filters. In addition, a set of two low pass
filters, with tunable break frequencies, are used to
control tilt coordination. All filter parameters are
adjustable in the tuning file.
Tuning Parameter Characteristics
In both the Classical and OverTilt Modes, tuning
parameters control several additional features:
Requires only three
parameters to tune for each linear channel including
Maintains maximum position
parameter keeping you from hitting limits.
Limits Tilt Rate and Tilt
Acceleration, eliminating false rotational cues.
Prepositions based on the
current input acceleration effectively doubling the
motion envelope, fully integrated with the maximum
Tracks the position,
velocity, tilt, and acceleration of the motion base,
selecting the optimum tilt angle and cue to be
Reduces filter reference
frame effects that are common in the Classical
Allows you to rapidly
manipulate the algorithm because it is based on