Disassembled Prismatic (SimMechanics)

Represent a disassembled prismatic joint with one translational degree of freedom along misaligned axes

Library

Joints/Disassembled Joints

Description

The Disassembled Prismatic block represents a single translational degree of freedom (DoF) along a pair of specified misaligned axes between two bodies. SimMechanics automatically assembles (aligns) the translation axes at simulation start.

This block is disassembled: you must connect each side of the Joint block to a Body block at a Body coordinate system (CS) point, but the origins of these Body CSs do not have to lie along a joint axis. As with the Prismatic Joint, these Body CS origins do not need to be spatially collocated points either.

You can connect any Joint block to two and only two Body blocks, and Joints have a default of two Connector Ports for connecting to base and follower Bodies. The disassembled joint axes are associated with the base and follower Bodies, respectively.

You can only use a disassembled Joint block to close a loop. One loop must have no more than one disassembled joint. You cannot connect a Disassembled Joint to an Actuator or Sensor block.

Disassembled prismatic axes of follower (blue) and base (red)

Dialog Box and Parameters

The dialog box has two active areas, Connection parameters and Parameters.

Connection Parameters

Current base: When you connect the base (B) Connector Port on the Disassembled Prismatic block to a Body CS Port on a Body, this parameter is automatically reset to the name of this Body CS. See the following Disassembled Prismatic base and follower Body Connector Ports figure.
Current follower: When you connect the follower (F) Connector Port on the Disassembled Prismatic block to a Body CS Port on a Body, this parameter is automatically reset to the name of this Body CS. See the following Disassembled Prismatic base and follower Body Connector Ports figure.

Disassembled Prismatic base and follower Body Connector Ports

Parameters

There is one Axes panel.

The entries on the Axes pane are required. They specify the directions of the two misaligned axes of the translational DoF that the Disassembled Prismatic represents.

Name: This column automatically displays the names of the two misaligned translation axes attached to base and follower bodies, respectively.
Axis of translation [x y z]: Enter here as two three-component vectors the two misaligned directional axes along which the base and follower bodies respectively can translate. The default vectors are [1 0 0] and [0 1 0], respectively. The axes are directed vectors whose overall signs matter.
Reference csys: Using the pull-down menu, choose the coordinate systems (World, the base Body CS, or the follower Body CS) whose coordinate axes the two vector axes of translation are oriented with respect to. The defaults are WORLD.

See Modeling Joints for more on representing DoFs with Disassembled Joints.

See Checking Schematic Topology and How SimMechanics Works for more on closing loops with disassembled joints.

Disassembled Cylindrical Disassembled Revolute