A motion function specifies the exact displacement, velocity, or acceleration applied to a joint as a function of time. You can specify any MSC.ADAMS function using the general expression capability. When the Motion Type is set to something other than Free, you can specify the function. The function options are:
Constant function - Creates a function expression that moves the joint displacement, velocity, or acceleration in a constant manner. You need to specify one value.
Step function – Creates a function expression that moves the joint displacement, velocity, or acceleration between two values with a smooth motion. Before and after the transition, the displacement, velocity, or acceleration of the joint is constant.
Harmonic function - Creates a sinusoidal displacement, velocity, or acceleration. When you select the Harmonic function type, additional text boxes appear, where you can enter the values of the parameters for a simple harmonic function.
Spline
function - Allows you to define the joint displacement, velocity,
or acceleration by entering a table of data. One column in the table is
the time, and the other column is the displacement, velocity, or acceleration
of the joint at that time.
ADAMS/Solver fits a smooth curve to the data point values by interpolating
the data points. Then, the function expression for the motion references
this curve to get the actual position of the joint during the simulation.
You must define at least four data points.
Expression function - In addition to using the pre-defined functions listed above, you can also enter the text for an MSC.ADAMS function expression by selecting Expression from the Function option menu. See a list of supported functions. Note, however, that you are restricted to mathematical functions, not result-dependent functions.