Connect bodies through joints, gears, and constraints

Connect bodies with joint and constraint blocks to assemble them into an articulated system. The joint blocks determine the maximum degrees of freedom—rotational and translational—allowed between the connected bodies. The constraint blocks reduce this number by applying kinematic relationships that often couple degrees of freedom. There are no restrictions on model topology: you can model kinematic trees such as a double pendulum and kinematic loops such as a four bar.

Workflow steps for assembling body subsystems into an articulated multibody model.

Connecting bodies with joints, positioning and orienting joint frames through rigid transforms, and guiding joint assembly through by specifying joint state targets.

Role of joints in a multibody model. Joints as systems of joint primitives with elementary degrees of freedom. Accounting for the effects of joint inertia in a model.

**Model an Open-Loop Kinematic Chain**

Assemble body subsystems and revolute joints into an open-loop kinematic chain.

**Model a Closed-Loop Kinematic Chain**

Assemble body subsystems and revolute joints into a closed-loop kinematic chain.

**Troubleshoot an Assembly Error**

Use Mechanics Explorer and Model Report to identify and correct a model assembly error.

Learn how to model gear constraints using simple gear models as examples.

Using the Simscape™ Statistics Viewer to determine the motion degrees of freedom in a mechanism.

Learn how to satisfy the assembly requirements of gear constraints using Rigid Transform blocks.

Use the Common Gear Constraint block to couple the rotational motions of the bodies comprising a planetary gear system.

Use a Point on Curve Constraint block to restrict the motion of an aircraft flap to a curved trajectory specified in a Spline block.