LIBRARY

MultibodyComponents

This is the documentation for the MultibodyComponents library. Here you will find the documentation for the various definitions contained in MultibodyComponents.

Note that this documentation is automatically generated primarily from the doc strings and metadata associated with those definitions.

Types

• CutJoint

• OrientationState - Specifies the type of orientation state variables used in a component.

• PartialLineForce - Base model for line force components that define the force law directly

• PartialOrientation - Partial component providing orientation state variables for a 3D frame.

• PartialTwoFrames - Partial model with two 3D frames.

• PlanarMechanics.PartialTwoFrameSensor - Partial model for sensors with two frames, displayed as an analog dial gauge.

• PlanarMechanics.PartialTwoFrames - Partial model with two frames.

• Renderable

• ResolveInFrame - Specifies the coordinate frame in which force/torque inputs are resolved.

• RootedFrame - Specifies which frame of a component is closest to the root of the kinematic tree.

• RotMat

• Shape - Base visual shape primitive for 3D rendering.

Connectors

• RealOutputArray

Components

• AbsoluteAngles - Measures absolute Euler/Cardan angles of a frame relative to the world.

• ArrowShape - Arrow shape primitive for 3D rendering.

• Body - Rigid body with mass, inertia tensor, and one frame connector.

• BodyBox - Rigid body with box shape. Mass properties are computed from the

• BodyCylinder - Rigid body with cylinder shape. Mass properties are computed from the

• BodyShape - Body with shape: a rigid rod (FixedTranslation) from frame_a to frame_b

• BoxShape - Box shape primitive for 3D rendering.

• BoxVisualizer - Frame-connected box visualizer with zero mass.

• Bushing - Compliant mount (bushing): roots one frame from the other through its own

• Cable - Cable / rope of total length l and mass m, modeled as n rigid

• CascadeServoController - Cascade motion controller with position, velocity, and force loops.

• Concat3 - Three-way array concatenation. Takes three array inputs of structural sizes

• ConeShape - Cone shape primitive for 3D rendering.

• ControlMixer - Static thrust mixer: maps three control channels into four thruster commands

• ControlledRotorCraft - Quadrotor with three PID feedback loops (altitude, roll, pitch) and a

• CutForce - Inline sensor measuring the cut force passing through the connection.

• CutMount - Zero-clearance mount that rigidly constrains selected directions and prescribes

• CutTorque - Inline sensor measuring the cut torque passing through the connection.

• CylinderShape - Cylinder shape primitive for 3D rendering.

• CylinderVisualizer - Frame-connected cylinder visualizer with zero mass.

• Cylindrical - Cylindrical joint: combined prismatic and revolute along/around the same axis.

• Damper - Linear damper acting as line force between frame_a and frame_b.

• Demux3 - Split a 3-element vector into three scalar outputs. Used in

• Demux4 - Split a 4-element vector into four scalar outputs. Used inside RotorCraft

• Demux6 - Split a 6-element vector into six scalar outputs. Used in

• Fixed - A component rigidly attached to the world frame with translation r

• FixedRotation - Fixed translation and rotation of frame_b with respect to frame_a.

• FixedTranslation - Fixed translation between two frames.

• Foo

• Force - Force acting between two frames, defined by 3 input signals resolved in

• GasForce2 - Rough approximation of the gas force in the cylinder of a combustion engine,

• GearConstraint - Ideal massless gear constraint between two arbitrary 3D shaft axes.

• JointRRP - Planar revolute - revolute - prismatic joint aggregation. Closes a planar

• JointRRR - Joint assembly of three revolute joints with parallel axes (hence RRR),

• JointSSP - Spherical - spherical - prismatic joint aggregation. Analytically closes a

• JointSSR - Spherical - spherical - revolute joint aggregation. Analytically closes a

• JointUPS - Universal - prismatic - spherical joint aggregation. A universal joint at

• JointUSP - Universal - spherical - prismatic joint aggregation. Analytically closes a

• JointUSR - Joint assembly consisting of a universal joint at frame_a, a

• Kinematic5 - A component emitting a 5th order polynomial trajectory.

• KinematicPTP - A component emitting a trajectory created by the point_to_point trajectory generator.

• KinematicPTPBoundedJerk - A component emitting a time-optimal point-to-point trajectory with bounded velocity,

• LQRControlledRotorCraft - Quadrotor under static LQR state feedback. The 13 measured signals from the

• LQRGain - Static multivariable (MIMO) gain block implementing y_out = K * u_in.

• LineForceBase - Base model for line force components.

• LineForceWithMass - Line force component with optional point mass on the line between two frames.

• Mounting1D - Propagates 1D rotational flange reactions into the 3D frame.

• Mux1 - Trivial adapter that wraps a single scalar input into a 1-element vector

• Mux3 - Bundle three scalar signals into a 3-element vector, y = [u1, u2, u3].

• NullJoint - Rigid connection between two frames (zero degrees of freedom).

• PacejkaSlippingWheel - Wheel with mass, inertia, and Pacejka magic-formula friction on the flat plane

• PacejkaWheelJoint - Joint for a wheel with Pacejka magic-formula friction rolling on the flat plane

• Planar - Planar joint: motion in a plane plus rotation about the plane normal.

• PlanarMechanics.AbsoluteAcceleration - Measures absolute acceleration and angular acceleration of the origin of a frame connector.

• PlanarMechanics.AbsolutePosition - Measures absolute position and orientation of the origin of a frame connector.

• PlanarMechanics.AbsoluteVelocity - Measures absolute velocity and angular velocity of the origin of a frame connector.

• PlanarMechanics.BasicAbsolutePosition - Measures absolute position and orientation resolved in a configurable frame.

• PlanarMechanics.BasicRelativePosition - Measures relative position and orientation (frame_b - frame_a) resolved in a

• PlanarMechanics.Body - Body component with mass and inertia.

• PlanarMechanics.BodyShape - Body with shape: a rigid rod (FixedTranslation) from frame_a to frame_b with a

• PlanarMechanics.Cable - Planar cable / rope of total length l and mass m, modeled as n rigid

• PlanarMechanics.CutForce - Measures the cut force between two rigidly connected frames.

• PlanarMechanics.CutTorque - Measures the cut torque between two rigidly connected frames.

• PlanarMechanics.Damper - Linear velocity-dependent damper.

• PlanarMechanics.DetachableMount - Detachable 2D spring-damper mount whose force and torque are scaled by the

• PlanarMechanics.DifferentialGear - A differential gear that distributes torque equally among two output flanges.

• PlanarMechanics.Distance - Measures the distance between the origins of two frame connectors.

• PlanarMechanics.Fixed - Frame fixed in the planar world frame at a given position and orientation.

• PlanarMechanics.FixedRotation - Fixed angular offset between two frames with no translational offset.

• PlanarMechanics.FixedTranslation - A fixed translation between two components (rigid rod).

• PlanarMechanics.FrameVisualizer2D - Visualizes a 2D frame as three colored axis cylinders (red=x, green=y, blue=z).

• PlanarMechanics.IdealPlanetary - Ideal planetary gearbox without inertia, elasticity, damping or backlash.

• PlanarMechanics.OneDOFRollingWheelJoint - An ideal rolling wheel joint constrained to move only along the x-axis without slip.

• PlanarMechanics.OneDOFSlippingWheelJoint - Simplified 1-DOF wheel joint with slip-dependent friction, constrained to the x-axis.

• PlanarMechanics.PlanarToMultiBody - Adapter between a 2D planar frame (frame_a) and a full 3D frame (frame_b).

• PlanarMechanics.Power - Measures the mechanical power transmitted between two rigidly connected frames.

• PlanarMechanics.PrescribedAcceleration - Prescribed acceleration of frame_b via input connectors.

• PlanarMechanics.PrescribedPose - Prescribed position and orientation of frame_b via input connectors.

• PlanarMechanics.PrescribedPosition - Prescribed position of frame_b via input connectors.

• PlanarMechanics.PrescribedVelocity - Prescribed velocity of frame_b via input connectors.

• PlanarMechanics.Prismatic - Prismatic (sliding) joint allowing translation along a fixed direction.

• PlanarMechanics.RelativeAcceleration - Measures relative acceleration and angular acceleration between the origins of two

• PlanarMechanics.RelativeForce - Relative force and torque acting between frame_a and frame_b, defined by input signals.

• PlanarMechanics.RelativePosition - Measures relative position and orientation between the origins of two frame connectors.

• PlanarMechanics.RelativeVelocity - Measures relative velocity and angular velocity between the origins of two frame connectors.

• PlanarMechanics.Revolute - Revolute joint: allows rotation about the z-axis while rigidly connecting positions.

• PlanarMechanics.SlipBasedWheelJoint - Slip-based wheel joint with slip-dependent friction characteristics.

• PlanarMechanics.Spring - Linear 2D translational spring with independent x and y stiffness.

• PlanarMechanics.SpringDamper - Linear 2D translational spring-damper with independent x, y, and phi stiffness and damping.

• PlanarMechanics.TransformAbsoluteVector - Rotates an absolute vector between frames via a two-step rotation through the

• PlanarMechanics.TransformRelativeVector - Rotates a relative vector between frames via a two-step rotation through the

• PlanarMechanics.World - The root component for all 2D planar mechanics models.

• PlanarMechanics.WorldForceTorque - External force and torque acting at frame_b, defined by input signals.

• PlanarMechanics.examples.EndEffector

• PlanarMechanics.examples.dyad_balans.Mux1

• PlanarMechanics.examples.excavator.AnchoredCylinderMount - A PlanarCylinderMount together with the two anchor translations that place its

• PlanarMechanics.examples.excavator.ControlledCylinder - A hydraulic cylinder axis with its own valve, sensors, and cascade controller.

• PlanarMechanics.examples.excavator.DigReference - Piston position references for the three excavator cylinders over one dig

• PlanarMechanics.examples.excavator.PlanarCylinderMount - Mounts a translational actuator between two planar frames as a line force

• PlanarMechanics.examples.excavator.ProportionalValve - Proportional 4/3 directional valve metering flow between a supply, a tank, and

• PlanarMechanics.examples.excavator.SoilContact - Soil reaction force acting on a digging tool at a flat soil surface.

• PlanarMechanics.examples.two_joint_robot.InverseKinematicsDriver - Drives an inverse robot model in Cartesian tool space: the tool-flange position of

• PlanarMechanics.examples.two_joint_robot.InverseModelDriver - Drives the joints of an inverse robot model at the acceleration level from a vector-valued reference acceleration and measures the torques required to realize the reference motion. The measured torques constitute a computed-torque feedforward signal.

• PlanarMechanics.examples.two_joint_robot.JointController - Joint-level tracking controller: selects the reference position and velocity for one joint from vector-valued trajectory signals and computes a torque command using a PID controller with external derivative and feedforward inputs. The derivative input is formed from the velocity reference and a filtered velocity measurement.

• PlanarMechanics.examples.two_joint_robot.TwoJointPlanarArm - Planar 2-joint serial arm: two revolute joints exposed through rotational flanges, two rigid links, and an end-effector body. Instantiated twice in TwoJointPlanarRobotPID: once as the simulated robot and once as an inverse model for computed-torque feedforward.

• PlanarMechanics.examples.two_joint_robot.UnknownTorqueSource - Applies an a-priori unknown torque to the spline and reports it as an output. The torque magnitude carries no equation of its own: it is determined by the constraints of the surrounding model. This is the actuation side of an inverse model whose motion is prescribed elsewhere, e.g. a robot whose tool position is prescribed by a forceless PrescribedPosition while the joints are driven by UnknownTorqueSource components: the reported torques then solve the inverse dynamics of the prescribed motion.

• PlaneShape - Plane shape primitive for 3D rendering.

• Power - Inline sensor measuring mechanical power transmitted from frame_a to frame_b.

• PrescribedAcceleration - Prescribed acceleration of frame_b via input connectors.

• PrescribedPose - Prescribed position and orientation of frame_b via input connectors.

• PrescribedPosition - Prescribed position of frame_b via input connectors.

• PrescribedVelocity - Prescribed velocity of frame_b via input connectors.

• Prismatic - Prismatic joint: translation along a single axis in 3D.

• PrismaticConstraint - Prismatic cut-joint that rigidly constrains the orientation of frame_b to that

• PrismaticWithLengthConstraint - Prismatic joint whose translational distance is computed analytically from a

• RelativeAngles - Measures relative Euler/Cardan angles between two frames.

• RelativePosition - Measures the relative position vector between two frames.

• Revolute - Revolute joint: rotation about a single axis in 3D.

• RevoluteConstraint - Revolute cut-joint that constrains frame_b to a single rotational degree of

• RevolutePlanarLoopConstraint - Revolute joint for closing planar kinematic loops.

• RevoluteWithLengthConstraint - Revolute joint whose angle is determined analytically by a length constraint

• RollingConstraintVerticalWheel - Rolling constraint for a vertical wheel rolling on the world x-z plane.

• RollingWheel - Ideal rolling wheel (mass + inertia) on the flat plane y = 0.

• RollingWheelJoint - Joint (no mass, no inertia) for an ideal rolling wheel on the flat plane y = 0.

• RollingWheelSet - Ideal two-wheel rolling axle with masses and inertia per wheel.

• RollingWheelSetJoint - Idealized two-wheel rolling axle (wheelset) without bodies.

• RotorCraft - Open-loop quadrotor airframe: a central Body with Euler-angle orientation,

• Selector

• ShapefileVisualizer - Frame-connected mesh visualizer with no mass or inertia.

• SlipWheelJoint - Joint for a wheel with slip-dependent friction rolling on the flat plane y = 0.

• SlippingWheel - Wheel with mass, inertia, and slip-dependent friction on the flat plane y = 0.

• SphereShape - Sphere shape primitive for 3D rendering.

• SphereVisualizer - Frame-connected sphere visualizer with zero mass.

• Spherical - Spherical joint: free rotation in all three directions (ball joint).

• SphericalConstraint - Spherical cut-joint (ball joint) that constrains the relative position of

• SphericalSpherical - Joint with two spherical-like ends connected by a fixed-length rod.

• Spring - Linear spring acting as line force between frame_a and frame_b.

• SpringDamperParallel - Linear spring and linear damper in parallel acting as line force between

• SpringShape - Spring coil shape primitive for 3D rendering.

• TexturedPlaneVisualizer - Frame-connected textured rectangle visualizer with no mass or inertia.

• Thruster - Idealized propeller thruster: applies a force along the local y-axis of

• Torque - Torque acting between two frames, defined by 3 input signals resolved in

• TrajectorySelector - Selects one axis from the vector-valued outputs of a multi-axis trajectory

• URDFBodyBox - Rigid body with box visualization, for URDF import.

• URDFBodyCylinder - Rigid body with cylinder visualization, for URDF import.

• URDFBodySphere - Rigid body with sphere visualization, for URDF import.

• URDFPrismatic - Prismatic joint preceded by a fixed translation and rotation.

• URDFRevolute - Revolute joint preceded by a fixed translation and rotation.

• Universal - Universal joint: two revolute joints in series with perpendicular axes.

• UniversalConstraint - Universal cut-joint that constrains frame_b to two rotational degrees of

• UniversalSpherical - Joint assembly: universal joint at frame_a + spherical joint at frame_b,

• World - The root component for all 3D multibody models.

• WorldForce - External force acting at frame_b, defined by 3 input signals.

• WorldTorque - External torque acting at frame_b, defined by 3 input signals.

• examples.Cartpole - Inverted pendulum on a cart.

• examples.OpenLoopCartpole - Cartpole mounted in a world, with the force input exposed as a top-level

• examples.suspension.DoubleSuspensionWithExcitationAndMass - Half-car model: two excited quarter-car suspensions (right mirror=false and

• examples.suspension.ExcitedWheelAssembly - Quarter-car suspension carrying a slipping wheel, excited by a time-varying road.

• examples.suspension.FullCar - Full four-wheel car model: four ExcitedWheelAssembly corner suspensions

• examples.suspension.HalfCar - Half-car model with two rolling wheels: two ExcitedWheelAssembly suspensions

• examples.suspension.QuarterCarSuspension - Double-wishbone quarter-car suspension linkage.

• examples.suspension.SuspensionWithExcitation - Quarter-car suspension driven by a sinusoidal wheel-position excitation.

• examples.suspension.SuspensionWithExcitationAndMass - Quarter-car model: an excited suspension carrying a chassis mass, constrained to

• examples.suspension.SuspensionWithWheelAndMass - Quarter-car model with a rolling wheel: an ExcitedWheelAssembly carrying a

• tests.DoublePendulum

Analyses

• ParallelKinematicRobotAnalysis - short ParallelKinematicRobotAnalysis analysis description

• RenderAnalysis

Examples

• OpenLoopRotorCraft - Open-loop quadrotor + world used for linearization. Wraps a RotorCraft

• PlanarMechanics.examples.DoubleBodyPend

• PlanarMechanics.examples.ParallelKinematicRobot

• PlanarMechanics.examples.PendulumTest - A free swinging pendulum.

• PlanarMechanics.examples.SlipBasedWheelTest - A slip-based wheel.

• PlanarMechanics.examples.SpringAndDamperTest - This example shows how to use a spring and a damper separately. The motion is constrained by a prismatic joint. The spring passes a point of zero length.

• PlanarMechanics.examples.SpringDamperSystemTest - This example shows how to use a spring and a damper in combination. The motion of the body is not constrained.

• PlanarMechanics.examples.TwoTrackModelTest - A double track model of a car.

• PlanarMechanics.examples.dyad_balans.DyadBalans2D - This example models a wheeled balancing robot with a cascade control system stabilizing the angle in the inner loop and the position in the outer loop.

• PlanarMechanics.examples.dyad_balans.DyadBalans2DFF - This is a continuation of the DyadBalans2D example, adding a feedforward generator computed using DyadControlSystems.feedforward_generator in the script compute_feedforward.jl. The feedforward generator provides a filtered position reference to the outer controller as well as an angle feedforward reference for the inner controller and a direct torque feedforward signal to be applied directly to the torque input. Both inner feedforward signals are connected to the u_ff port on the LimPID components.

• PlanarMechanics.examples.dyad_balans.SimpleMotor

• PlanarMechanics.examples.excavator.Excavator - Planar excavator digging through soil with hydraulically actuated boom, stick,

• PlanarMechanics.examples.trebuchet.Trebuchet - A planar trebuchet built from PlanarMechanics components.

• PlanarMechanics.examples.trebuchet.TrebuchetDetachable - A planar trebuchet that releases its projectile through a gated compliant mount.

• PlanarMechanics.examples.two_joint_robot.TwoJointPlanarRobotPID - Planar 2-joint serial robot tracking a jerk-bounded reference with per-joint JointController controllers. Computed-torque feedforward is obtained from a second instance of the arm acting as an inverse model: its joints are driven at the acceleration level by the reference trajectory through an InverseModelDriver, and the torques required to realize the reference motion are measured and fed to the feedforward inputs of the controllers.

• PlanarMechanics.examples.two_joint_robot.TwoJointPlanarRobotPIDCartesian - Planar 2-joint serial robot tracking a jerk-bounded reference specified in Cartesian tool-flange space. A single inverse instance of the arm solves both the inverse kinematics and the inverse dynamics: its tool flange is constrained to the Cartesian reference without applying force there, while its joints are actuated by unknown torques (InverseKinematicsDriver). The unknown torques constitute the computed-torque feedforward, and joint angle and velocity references for the per-joint JointController feedback controllers are measured on the same inverse instance.

• examples.BodyBoxPend

• examples.BodyCylinderPend

• examples.BodyShapePend

• examples.CartWithInput - Cartpole driven in open loop by a cosine force signal.

• examples.CartWithSwingup - Cartpole with an energy-based swing-up controller and a stabilizing LQR

• examples.Engine1b - # One-cylinder engine with gas force (planar loop closed by a constraint)

• examples.Engine1b_analytic - # One-cylinder engine with gas force (planar loop solved analytically)

• examples.EulerBody

• examples.FourBar - Planar four-bar linkage closed with a RevolutePlanarLoopConstraint.

• examples.FourBar2 - Four-bar linkage closed with a cut joint.

• examples.FourBar3 - Four-bar linkage closed with the UniversalSpherical joint assembly.

• examples.LinearPend

• examples.Pend

• examples.QuaternionBody - # Free body with quaternion state

• examples.SpringMassSystem - # Spring-mass system

• examples.ThreeSprings - # Three springs

• examples.TrajectoryPlannersTest - Example model for the Kinematic5 trajectory planner. The velocity output is

• tests.CutMountTest - # CutMount Test

• tests.CylindricalJointTest - # Cylindrical Joint Test

• tests.DrivingWheelSetTest - # Driving Wheel Set Test

• tests.GearConstraintTest - # Gear Constraint Test

• tests.JointRRRTest - # JointRRR test

• tests.JointUSRTest - # JointUSR test

• tests.PacejkaWheelInWorld - # Pacejka Wheel In World

• tests.PlanarJointTest - # Planar Joint Test

• tests.PointGravityOrbit - Free-floating body in a point-gravity field (structural point_gravity = true

• tests.PrescribedAccelerationTest - # Prescribed Acceleration Test

• tests.PrescribedPoseTest - # Prescribed Pose Test

• tests.PrescribedPositionTest - # Prescribed Position Test

• tests.PrescribedVelocityTest - # Prescribed Velocity Test

• tests.PrismaticConstraintTest - # Prismatic Constraint (closed loop with a spring)

• tests.RevoluteConstraintTest - # Revolute Constraint (closed loop with a spring)

• tests.RevolutePendulumRef - # Revolute Pendulum (reference for Spherical joint tests)

• tests.Sensors3DTest - # 3D Sensors Test

• tests.SlipVsPacejkaSpinUp - # Slip vs Pacejka spin-up comparison

• tests.SlipWheelInWorld - # Slip Wheel In World

• tests.SlipWheelOnIncline - # Slip Wheel on an inclined plane

• tests.SlipWheelOnSurface - # Slip Wheel on a moving surface

• tests.SphericalConstraintTest - # Spherical Constraint (closed loop with a spring)

• tests.SphericalFreeSpin - # Spherical Free Spin (zero gravity)

• tests.SphericalPendulum - # Spherical Pendulum

• tests.SphericalPendulumConstraint - # Spherical Pendulum (joint as pure constraint, body holds quaternion state)

• tests.SphericalPendulumQuatJoint - # Spherical Pendulum (quaternion state in joint)

• tests.UniversalConstraintTest - # Universal Constraint (closed loop with a spring)

• tests.UniversalPendulum - # Universal Pendulum

• tests.WheelInWorld - # Wheel In World

Tests

• PlanarMechanics.BodyShapePendulumTest - Pendulum with BodyShape: Fixed -> Revolute -> BodyShape.

• PlanarMechanics.CentrifugalTest - Centrifugal acceleration test: a body on a rotating arm with an AbsoluteVelocity sensor.

• PlanarMechanics.CutForceTest - Test for CutForce sensor: a damped pendulum with three CutForce sensors

• PlanarMechanics.CutTorqueTest - Test for CutTorque sensor: a damped pendulum with a CutTorque sensor, a WorldForce

• PlanarMechanics.OneDOFRollingWheelJointTest - Test for OneDOFRollingWheelJoint: a body connected to an ideal rolling wheel.

• PlanarMechanics.OneDOFSlippingWheelSegwayTest - Test for OneDOFSlippingWheelJoint: planar segway model.

• PlanarMechanics.OneDOFSlippingWheelSpinningTest - Test for OneDOFSlippingWheelJoint: a wheel spinning in place.

• PlanarMechanics.PlanarToMultiBodyEmbeddedTest - Embedding test of PlanarToMultiBody: the planar world is mounted at a nonzero

• PlanarMechanics.PlanarToMultiBodyKinematicTest - Kinematic test of PlanarToMultiBody: a prescribed planar pose is lifted into

• PlanarMechanics.PlanarToMultiBodyPendulumTest - Dynamic test of PlanarToMultiBody: a swinging planar pendulum drives the

• PlanarMechanics.PrescribedAccelerationTest - A body whose frame_a is driven by a PrescribedAcceleration component

• PlanarMechanics.PrescribedPoseTest - A body whose frame_a is driven by a PrescribedPose component. Position

• PlanarMechanics.PrescribedPositionTest - A body whose frame_a is driven by a PrescribedPosition component with

• PlanarMechanics.PrescribedVelocityTest - A body whose frame_a is driven by a PrescribedVelocity component with

• PlanarMechanics.RelativeForceTest - Test for RelativeForce: a damped pendulum with an applied sinusoidal relative force.

• PlanarMechanics.SensorsTest - Sensor test with two free-falling bodies: validates all 6 sensor types.

• PlanarMechanics.TestPlanarCableEndJoints - Planar cable test: World → Cable(end_joints=true, n=3) → Body.

• PlanarMechanics.TestPlanarCableNoEndJoints - Planar cable test: World → Cable(end_joints=false, n=3) → Body.

• PlanarMechanics.WorldForceTest - Test for WorldForceTorque: a damped pendulum with an applied sinusoidal force.

• tests.TestCableEndJoints - Simple test: World → Cable(end_joints=true, n=2) → Body

• tests.TestCableNoEndJoints - Simple test: World → Cable(end_joints=false, n=2) → Body