initialGuessVariables

List all kinematic variables assigned as initial guesses

Description

initialGuessVariables(ks) lists the kinematic variables in the KinematicsSolver object ks currently assigned as guesses. Both joint and frame variables can serve in this role. Those that do bias the solver toward one of equally plausible solutions when several exist. Guess variables are optional but important solver guides in some kinematic problems.

The output is a table with the guess variables in rows. Each row gives the ID of a variable, the type and block path of the joint to which it belongs if a joint variable, the base and follower frames from which it derives if a frame variable, and the unit for its numerical value. The variables rank in the order added.

No attempt is made to satisfy guess variables. They are a starting point in the search for a solution. Use them merely to bias the solver toward a suitable solution when several exist.

The figure shows the variables of a general KinematicsSolver object. Target (T), guess (G), and output (O) variables can be joint variables (J) or frame variables (F). The same variable can serve as guess and output, but if it serves as target, it cannot double as guess. Assigning a guess variable as target clears it as guess.

Input Arguments

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A KinematicsSolver object is the representation of a Simscape Multibody model used for kinematic analysis.

Example: ks = simscape.multibody.KinematicsSolver('sm_double_pendulum')

Data Types: KinematicsSolver object

Introduced in R2019a