Simulation and Analysis

Run a simulation, visualize a model, and run a kinematic analysis

Update the block diagram to assemble the multibody model and visualize its initial configuration. The visualization opens in Multibody Explorer. Simulate the model to play an interactive animation. Be sure to pick a solver suited for physical models, such as daessc, and to specify a maximum time step small enough to capture the fastest meaningful change expected during simulation.

Open Camera Manager to add a moving, dynamic camera with which to capture the animation. Dynamic cameras can be of two types: keyframed or tracking. Keyframed cameras move between view points created interactively in Multibody Explorer. Tracking cameras attach to and aim at frames in the model. Use Video Creator or the smwritevideo function to record an animation in a video format.

Use the KinematicsSolver class to create a kinematic representation of a model and formulate a kinematic problem to solve. KinematicsSolver objects contain all the joint variables available in a model. Complement them with frame variables and assign both joint and frame variables as targets, guesses, and outputs for analysis.

Tools

Multibody ExplorerVisualize and explore multibody models
Camera ManagerCreate, edit, and delete dynamic cameras
Video CreatorCreate and configure videos of multibody animations

Model Settings

Functions

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simscape.multibody.tirreadRead TIR file (Since R2021b)
smwritevideoConfigure and create multibody animation videos
smwritevideoConfigure and create multibody animation videos

Representing the Assembly

KinematicsSolverSolve kinematics problems for a multibody model

Configuring Options

setVariableUnitChange physical unit of kinematic variable

Listing Variables

frameVariablesList kinematic variables associated with frame pairs
initialGuessVariablesList all kinematic variables assigned as initial guesses
jointVelocityVariablesList all kinematic variables associated with joint velocities
jointPositionVariablesList all kinematic variables associated with joint positions
outputVariablesList all kinematic variables assigned as outputs
targetVariablesList kinematic variables assigned as targets

Adding Variables

addFrameVariablesCreate kinematic variables from select frame pair in KinematicsSolver object
addInitialGuessVariablesAssign kinematic variables from KinematicsSolver object as guesses
addOutputVariablesAssign kinematic variables from the KinematicsSolver object as outputs
addTargetVariablesAssign kinematic variables from KinematicsSolver object as targets

Clearing Variables

clearFrameVariablesDrop all frame variables from the KinematicsSolver object
clearInitialGuessVariablesDrop all guess variables from the KinematicsSolver object
clearOutputVariablesDrop all output variables from the KinematicsSolver object
clearTargetVariablesDrop all target variables from the KinematicsSolver object

Removing Variables

removeFrameVariablesDrop select frame variables from the KinematicsSolver object
removeInitialGuessVariablesDrop select guess variables from the KinematicsSolver object
removeOutputVariablesDrop select output variables from the KinematicsSolver object
removeTargetVariablesDrop select target variables from the KinematicsSolver object

Running the Analysis

generateCodeGenerate C code to run kinematic analysis on KinematicsSolver object
solveRun kinematic analysis for KinematicsSolver object

Visualize the Solution of Analysis

closeViewerClose the Kinematics Solver Viewer window
viewSolutionOpen Multibody Explorer to visualize KinematicsSolver solution
simscape.multibody.DynamicsResultDynamics Results of Multibody Models (Since R2024a)

Topics

Basic Visualization

  • Enable Multibody Explorer
    Set the model configuration parameters to ensure that Multibody Explorer opens automatically on model update or simulation.
  • Manipulate the Visualization Viewpoint
    Select a standard view, set the up-axis convention, and use mouse shortcuts to rotate, roll, pan, or zoom a model.
  • Using Operating Points to Initialize Multibody Models
    This example shows how to use operating points to initialize multibody models, specify the initial positions and velocities of the joints in a model, and start simulations of flexible bodies from their deformed states.
  • Update and Simulate a Model
    Workflow steps for updating and simulating a Simscape™ Multibody™ model.
  • Visualize a Model and Its Components
    Visualization is not only a central part of a multibody simulation, but also an essential tool in modeling bodies and verifying their shapes, sizes, frame placements, and colors. Here is an overview of the visualization utilities available in the Simscape Multibody environment and the roles they play in your modeling workflow.
  • Visualize Simscape Multibody Frames
    Use Multibody Explorer frame highlights and Graphic blocks to visualize frames.

Advanced Visualization

Cameras and Video Creation

  • Create a Dynamic Camera
    Use Camera Manager to create or edit a model visualization camera with a moving viewpoint.
  • Create a Model Animation Video
    Save an animation in video format using Video Creator or the smwritevideo function.
  • Visualization Cameras
    Distinction between dynamic cameras and the global camera. Camera Manager as a tool for creating dynamic cameras. Dynamic camera keyframe and tracking modes.
  • Working with Animation
    Review how model animations work and explore the basic controls available for animations.

Troubleshooting

Featured Examples

Configuring Dynamic Cameras - Vehicle Slalom

Configuring Dynamic Cameras - Vehicle Slalom

Illustrates the use of dynamic cameras to view a vehicle traversing a slalom course. The vehicle accelerates from stationary to a fixed speed and then enters the slalom course. Upon exiting, the vehicle decelerates back to stationary before the end of the road. The model has four dynamic cameras: three with tracking parameterization and one with keyframes. The tracking cameras show the front and side views of the vehicle from a fixed offset relative to the vehicle, along with the view from the driver's perspective. The keyframed camera shows a sweeping view of the vehicle maneuver.

Double Pendulum in Simulink and Simscape Multibody

Double Pendulum in Simulink and Simscape Multibody

Two models of a double pendulum, one using Simulink® input/output blocks and one using Simscape™ Multibody™.

Perform Forward and Inverse Kinematics on a Five-Bar Robot

Perform Forward and Inverse Kinematics on a Five-Bar Robot

Use the KinematicsSolver object to perform forward kinematics (FK) and inverse kinematics (IK) on a five-bar robotic mechanism. First, the example demonstrates how to perform FK analyses to calculate a singularity-free workspace for a five-bar robot. Then the example shows how to perform IK analyses to compute the motor angles that correspond to an end-effector trajectory within that workspace.

Pick and Place Robot Using Forward and Inverse Kinematics

Pick and Place Robot Using Forward and Inverse Kinematics

Model a delta robot performing a pick and place task.

Single Pendulum in Simulink and Simscape Multibody

Single Pendulum in Simulink and Simscape Multibody

A single pendulum modeled using Simulink® input/output blocks and using Simscape™ Multibody™. The initial angle for the joint is defined by a MATLAB® variable. The annotations on the integrator block show the initial angle of the joint with respect to the world frame.