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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.


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simscape.multibody.ComponentAbstract base class for components
simscape.multibody.JointAbstract base class for joints
simscape.multibody.MultibodySpecify structure of multibody system
simscape.multibody.RigidBodyConstruct rigid body
simscape.multibody.RigidTransformConstruct rigid transform
simscape.multibody.SolidConstruct rigid solid
simscape.multibody.WorldFrameConstruct world frame
simscape.multibody.BearingJointConstruct bearing joint
simscape.multibody.BushingJointConstruct bushing joint
simscape.multibody.CartesianJointConstruct Cartesian joint
simscape.multibody.ConstantVelocityJointConstruct constant-velocity joint
simscape.multibody.CylindricalJointConstruct cylindrical joint
simscape.multibody.GimbalJointConstruct gimbal joint
simscape.multibody.JointAbstract base class for joints
simscape.multibody.LeadScrewJointConstruct lead-screw joint
simscape.multibody.PinSlotJointConstruct pin-slot joint
simscape.multibody.PlanarJointConstruct planar joint
simscape.multibody.PrismaticJointConstruct prismatic joint
simscape.multibody.RectangularJointConstruct rectangular joint
simscape.multibody.RevoluteJointConstruct revolute joint
simscape.multibody.SixDofJointConstruct bushing joint
simscape.multibody.SphericalJointConstruct spherical joint
simscape.multibody.TelescopingJointConstruct telescoping joint
simscape.multibody.UniversalJointConstruct universal joint
simscape.multibody.WeldJointConstruct weld joint
simscape.multibody.ConstantVelocityPrimitiveConstruct constant-velocity joint primitive
simscape.multibody.JointPrimitiveAbstract base class to construct joint primitives
simscape.multibody.LeadScrewPrimitiveConstruct lead-screw primitive
simscape.multibody.PrismaticPrimitiveConstruct prismatic joint primitive
simscape.multibody.RevolutePrimitiveConstruct revolute joint primitive
simscape.multibody.SphericalPrimitiveConstruct spherical joint primitive
simscape.multibody.AlignedAxesRotationConstruct rotation by using aligned-axes parameterization
simscape.multibody.ArbitraryAxisRotationConstruct rotation by specifying custom axis-angle pair
simscape.multibody.CartesianTranslationConstruct Cartesian translation
simscape.multibody.CylindricalTranslationConstruct cylindrical-axis translation
simscape.multibody.QuaternionRotationConstruct rotation by using unit quaternion
simscape.multibody.RotationAbstract base class for 3-D rotations
simscape.multibody.RotationMatrixRotationConstruct rotation by using rotation matrix
simscape.multibody.RotationSequenceRotationConstruct rotation by using rotation-sequence parameterization
simscape.multibody.TransformationConstruct transformation
simscape.multibody.TranslationAbstract base class for 3-D translations
simscape.multibody.StandardAxisRotationConstruct rotation by using standard-axis parameterization
simscape.multibody.StandardAxisTranslationConstruct standard-axis translation
simscape.multibody.ZeroRotationConstruct zero rotation
simscape.multibody.ZeroTranslationConstruct zero translation
simscape.multibody.CompiledMultibodyCompiled multibody system
simscape.multibody.StateState of compiled multibody system

Simscape Blocks

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Joints with One or No Primitives

Prismatic JointJoint with one prismatic primitive
Revolute JointJoint with one revolute primitive
Spherical JointJoint with one spherical primitive
Weld JointJoint with zero primitives

Joints with Multiple Primitives

Bearing JointJoint with one prismatic and three revolute primitives
Bushing JointJoint with three prismatic and three revolute primitives
Cartesian JointJoint with three prismatic primitives
Cylindrical JointJoint with one prismatic and one revolute primitives possessing parallel motion axes
Gimbal JointJoint with three revolute primitives
Pin Slot JointJoint with one prismatic and one revolute primitives possessing mutually orthogonal motion axes
Planar JointJoint with one revolute and two prismatic primitives
Rectangular JointJoint with two prismatic primitives
6-DOF JointJoint with one spherical and three prismatic primitives
Telescoping JointJoint with one prismatic and one spherical joint primitive
Universal JointJoint with two revolute primitives

Joints with Coupled Degrees of Freedom

Constant Velocity JointJoint that enforces a constant-velocity kinematic constraint between two shafts
Lead Screw JointJoint with coupled rotational and translational degrees of freedom
Bevel Gear ConstraintKinematic constraint between two bevel gear bodies with angled intersecting rotation axes
Common Gear ConstraintKinematic constraint between two coplanar spur gear bodies with parallel rotation axes
Rack and Pinion ConstraintKinematic constraint between a translating rack body and a rotating pinion body
Worm and Gear ConstraintKinematic constraint between worm and gear bodies with perpendicular non-intersecting rotation axes
Belt-Cable EndTip of the cord of a pulley system
Belt-Cable PropertiesGeneral characteristics of the cord of a pulley system
Belt-Cable SpoolSource and sink of cord in a pulley system
PulleyWheel wrapped in a cord for the transmission of torque and motion
Angle ConstraintFixed angle between two frame Z axes
Distance ConstraintFixed distance between two frame origins
Point on Curve ConstraintKinematic constraint between frame origin and curved path
Point on Surface ConstraintKinematic constraint between frame origin and 2-D surface


Assembling Bodies with Joints

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.