Disassembled Revolute (SimMechanics)

Represent a disassembled revolute joint with one rotational degree of freedom about misaligned axes

Library

Joints/Disassembled Joints

Description

The Disassembled Revolute block represents a single rotational degree of freedom (DoF) along a pair of specified misaligned axes between two bodies. SimMechanics automatically assembles (aligns) the rotation 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 need to be spatially collocated points or lie along a joint axis.

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 revolute 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 Revolute 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 Revolute base and follower Body Connector Ports figure.
Current follower: When you connect the follower (F) Connector Port on the Disassembled Revolute 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 Revolute base and follower Body Connector Ports figure.

Disassembled Revolute 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 rotational DoF that the Disassembled Revolute represents.

Name: This column automatically displays the names of the two misaligned rotation axes attached to base and follower bodies, respectively.
Axis of rotation [x y z]: Enter here as two three-component vectors the two misaligned directional axes about which the base and follower bodies respectively can rotate. 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 rotation 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 Prismatic Disassembled Spherical