# Assembly

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.

## Classes

## Simscape Blocks

## Topics

### Assembling Bodies with Joints

**Creating a Multibody with different joints in MATLAB**

This example shows how to build a multibody containing various joints in MATLAB.**How Multibody Assembly Works**

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

Workflow steps for assembling body subsystems into an articulated multibody model.**Modeling Joint Connections**

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.

### Constraining Multibody Assemblies

**Assemble a Gear Model**

Learn how to satisfy the assembly requirements of gear constraints using Rigid Transform blocks.**Counting Degrees of Freedom**

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

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

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

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