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Drake
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Drake
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Namespaces | |
| benchmarks | |
| contact_solvers | |
| fem | |
| hydroelastics | |
| meshcat | |
| mpm | |
| parsing | |
| test | |
| test_utilities | |
Classes | |
| struct | AddMultibodyPlantSceneGraphResult |
Temporary result from AddMultibodyPlantSceneGraph. More... | |
| class | AngleBetweenVectorsConstraint |
Constrains that the angle between a vector a and another vector b is between [θ_lower, θ_upper]. More... | |
| class | AngleBetweenVectorsCost |
Implements a cost of the form c*(1-cosθ), where θ is the angle between two vectors a and b. More... | |
| class | ArticulatedBodyInertia |
| Articulated Body Inertia is the inertia that a body appears to have when it is the base (or root) of a rigid-body system, also referred to as Articulated Body in the context of articulated body algorithms. More... | |
| class | BallRpyJoint |
| This Joint allows two bodies to rotate freely relative to one another. More... | |
| struct | CalcGridPointsOptions |
| class | CentroidalMomentumConstraint |
| Impose the constraint CentroidalMomentum(q, v) - h_WC = 0 with decision variables [q;v;h_WC] or CentroidalAngularMomentum(q, v) - k_WC = 0 with decision variables [q; v; k_WC] h_WC is the 6D spatial momentum (linear and angular momentum about the center of mass C) expressed in the world frame (W). More... | |
| class | CollisionFilterGroups |
| This is storage for parsed collision filter groups and group pairs. More... | |
| class | ComInPolyhedronConstraint |
| Constrains the center of mass to lie within a polyhedron lb <= A * p_EC <= ub where p_EC is the position of the center-of-mass (C) expressed in a frame E. More... | |
| class | ComPositionConstraint |
| Impose the constraint p_EScm(q) - p_EC = 0, where p_EScm(q) is a function that computes the center-of-mass (COM) position from robot generalized position q, expressed in a frame E. More... | |
| class | ConstraintRelaxingIk |
| A wrapper class around the IK planner. More... | |
| class | ContactResults |
| A container class storing the contact results information for each contact pair for a given state of the simulation. More... | |
| class | ContactResultsToLcmSystem |
| A System that encodes ContactResults into a lcmt_contact_results_for_viz message. More... | |
| struct | ContactWrench |
| Stores the contact wrench (spatial force) from Body A to Body B applied at point Cb. More... | |
| class | ContactWrenchEvaluator |
| class | ContactWrenchFromForceInWorldFrameEvaluator |
| The contact wrench is τ_AB_W = 0, f_AB_W = λ Namely we assume that λ is the contact force from A to B, applied directly at B's witness point. More... | |
| class | CoulombFriction |
| Parameters for Coulomb's Law of Friction, namely: More... | |
| class | DeformableContactInfo |
| A class containing information regarding contact and contact response between two geometries belonging to a pair of bodies with at least one of them being a deformable body. More... | |
| class | DeformableModel |
| DeformableModel implements the interface in PhysicalModel and provides the functionalities to specify deformable bodies. More... | |
| class | DifferentialInverseKinematicsIntegrator |
| A LeafSystem that integrates successive calls to DoDifferentialInverseKinematics (which produces joint velocity commands) to produce joint position commands. More... | |
| class | DifferentialInverseKinematicsParameters |
| Contains parameters for differential inverse kinematics. More... | |
| struct | DifferentialInverseKinematicsResult |
| class | DistanceConstraint |
| Constrains the distance between a pair of geometries to be within a range [distance_lower, distance_upper]. More... | |
| class | DoorHinge |
| This ForceElement models a revolute DoorHinge joint that could exhibit different force/torque characteristics at different states due to the existence of different type of torques on the joint. More... | |
| struct | DoorHingeConfig |
| Configuration structure for the DoorHinge. More... | |
| struct | ExternallyAppliedSpatialForce |
| class | ExternallyAppliedSpatialForceMultiplexer |
| Concatenates multiple std::vector<>'s of ExternallyAppliedSpatialForce<T>. More... | |
| class | FixedOffsetFrame |
| FixedOffsetFrame represents a material frame F whose pose is fixed with respect to a parent material frame P. More... | |
| class | ForceDensityField |
| The ForceDensityField class is an abstract base class that represents a force density field affecting deformable bodies in a MultibodyPlant. More... | |
| class | ForceElement |
| A ForceElement allows modeling state and time dependent forces in a MultibodyTree model. More... | |
| class | Frame |
| Frame is an abstract class representing a material frame (also called a physical frame) of its underlying RigidBody. More... | |
| class | FrameBase |
| FrameBase is deprecated and will be removed on or after 2025-01-01. More... | |
| class | GaussianTriangleQuadratureRule |
| class | GazeTargetConstraint |
| Constrains a target point T to be within a cone K. More... | |
| struct | GeometryPairContactWrenchEvaluatorBinding |
| class | GlobalInverseKinematics |
| Solves the inverse kinematics problem as a mixed integer convex optimization problem. More... | |
| class | GravityForceField |
| A uniform gravitational force density field for a uniform density object. More... | |
| class | HydroelasticContactInfo |
| A class containing information regarding contact and contact response between two geometries attached to a pair of bodies. More... | |
| class | HydroelasticContactInfo< symbolic::Expression > |
| Full specialization of HydroelasticContactInfo for T = Expression, with no member data. More... | |
| class | InverseKinematics |
| Solves an inverse kinematics (IK) problem on a MultibodyPlant, to find the postures of the robot satisfying certain constraints. More... | |
| class | Joint |
| A Joint models the kinematical relationship which characterizes the possible relative motion between two bodies. More... | |
| class | JointActuator |
| The JointActuator class is mostly a simple bookkeeping structure to represent an actuator acting on a given Joint. More... | |
| class | LinearBushingRollPitchYaw |
| This ForceElement models a massless flexible bushing that connects a frame A of a link (body) L0 to a frame C of a link (body) L1. More... | |
| class | LinearSpringDamper |
| This ForceElement models a spring-damper attached between two points on two different bodies. More... | |
| class | ManipulatorEquationConstraint |
| A Constraint to impose the manipulator equation: 0 = (Buₙ₊₁ + ∑ᵢ (Jᵢ_WBᵀ(qₙ₊₁)ᵀ * Fᵢ_AB_W(λᵢ,ₙ₊₁)) More... | |
| class | MinimumDistanceLowerBoundConstraint |
| Constrain min(d) >= lb, namely the signed distance between all candidate pairs of geometries (according to the logic of SceneGraphInspector::GetCollisionCandidates()) to be no smaller than a specified minimum distance lb. More... | |
| class | MinimumDistanceUpperBoundConstraint |
| Constrain min(d) <= ub, namely at least one signed distance between a candidate pairs of geometries (according to the logic of SceneGraphInspector::GetCollisionCandidates()) to be no larger than a specified ub. More... | |
| class | MultibodyElement |
| A class representing an element (subcomponent) of a MultibodyPlant or (internally) a MultibodyTree. More... | |
| class | MultibodyForces |
| A class to hold a set of forces applied to a MultibodyTree system. More... | |
| class | MultibodyPlant |
| MultibodyPlant is a Drake system framework representation (see systems::System) for the model of a physical system consisting of a collection of interconnected bodies. More... | |
| struct | MultibodyPlantConfig |
| The set of configurable properties on a MultibodyPlant. More... | |
| class | MultibodyPlantRemodeling |
| class | MultibodyPlantTester |
| class | OrientationConstraint |
| Constrains that the angle difference θ between the orientation of frame A and the orientation of frame B to satisfy θ ≤ θ_bound. More... | |
| class | OrientationCost |
Implements a cost of the form c * (1 - cos(θ)), where θ is the angle between the orientation of frame A and the orientation of frame B, and c is a cost scaling. More... | |
| class | PackageMap |
| Maps ROS package names to their full path on the local file system. More... | |
| class | Parser |
| Parses model description input into a MultibodyPlant and (optionally) a SceneGraph. More... | |
| struct | PdControllerGains |
| PD controller gains. More... | |
| class | PhysicalModel |
| (Internal) PhysicalModel provides the functionalities to extend the type of physical model of MultibodyPlant. More... | |
| class | PlanarJoint |
| This joint models a planar joint allowing two bodies to translate and rotate relative to one another in a plane with three degrees of freedom. More... | |
| class | PointPairContactInfo |
| A class containing information regarding contact response between two bodies including: More... | |
| class | PointToLineDistanceConstraint |
| Constrain that the distance between a point P on frame B1 and another line L on frame B2 is within a range [distance_lower, distance_upper]. More... | |
| class | PointToPointDistanceConstraint |
| Constrain that the distance between a point P1 on frame B1 and another point P2 on frame B2 is within a range [distance_lower, distance_upper]. More... | |
| class | PolyhedronConstraint |
| Constrain the position of points P1, P2, ..., Pn to satisfy the constraint A. More... | |
| class | PositionConstraint |
| Constrains the position of a point Q, rigidly attached to a frame B, to be within a bounding box measured and expressed in frame A. More... | |
| class | PositionCost |
| Implements a cost of the form (p_AP - p_AQ)ᵀ C (p_AP - p_AQ), where point P is specified relative to frame A and point Q is specified relative to frame B, and the cost is evaluated in frame A. More... | |
| class | PrismaticJoint |
| This Joint allows two bodies to translate relative to one another along a common axis. More... | |
| class | PrismaticSpring |
| This ForceElement models a linear spring attached to a PrismaticJoint and applies a force to that joint according to. More... | |
| class | Propeller |
| A System that connects to the MultibodyPlant in order to model the effects of one or more controlled propellers acting on a Body. More... | |
| struct | PropellerInfo |
| Parameters that describe the kinematic frame and force-production properties of a single propeller. More... | |
| class | QuaternionEulerIntegrationConstraint |
| If we have a body with orientation quaternion z₁ at time t₁, and a quaternion z₂ at time t₂ = t₁ + h, with the angular velocity ω (expressed in the world frame), we impose the constraint that the body rotates at a constant velocity ω from quaternion z₁ to quaternion z₂ within time interval h. More... | |
| class | QuaternionFloatingJoint |
| This Joint allows two bodies to move freely relatively to one another. More... | |
| class | RationalForwardKinematics |
| For certain robots (whose joint transforms are algebraic functions of joint variables, for example revolute/prismatic/floating-base joints), we can represent the pose (position, orientation) of each body, as rational functions, namely n(s) / d(s) where both the numerator n(s) and denominator d(s) are polynomials of s, and s is some variable related to the generalized position. More... | |
| class | RevoluteJoint |
| This Joint allows two bodies to rotate relatively to one another around a common axis. More... | |
| class | RevoluteSpring |
| This ForceElement models a torsional spring attached to a RevoluteJoint and applies a torque to that joint. More... | |
| class | RigidBody |
| The term rigid body implies that the deformations of the body under consideration are so small that they have no significant effect on the overall motions of the body and therefore deformations can be neglected. More... | |
| class | RigidBodyFrame |
| A RigidBodyFrame is a material Frame that serves as the unique reference frame for a RigidBody. More... | |
| class | RotationalInertia |
| This class describes the mass distribution (inertia properties) of a body or composite body about a particular point. More... | |
| class | RpyFloatingJoint |
| This Joint allows a rigid body to move freely with respect to its parent rigid body. More... | |
| class | ScopedName |
| A delimited string name for a multibody element, e.g., "robot1::torso". More... | |
| class | ScrewJoint |
| This joint models a screw joint allowing two bodies to rotate about one axis while translating along that same axis with one degree of freedom. More... | |
| struct | SignedDistanceWithTimeDerivative |
| The struct containing the signed distance and its time derivative between a pair of geometries. More... | |
| class | SpatialAcceleration |
| This class represents a spatial acceleration A and has 6 elements with an angular (rotational) acceleration α (3-element vector) on top of a translational (linear) acceleration 𝐚 (3-element vector). More... | |
| class | SpatialForce |
| This class represents a spatial force F (also called a wrench) and has 6 elements with a torque 𝛕 (3-element vector) on top of a force 𝐟 (3-element vector). More... | |
| class | SpatialInertia |
| This class represents the physical concept of a Spatial Inertia. More... | |
| class | SpatialMomentum |
| This class represents a spatial momentum L and has 6 elements with an angular (rotational) momentum 𝐡 (3-element vector) on top of a translational (linear) momentum 𝐥 (3-element vector). More... | |
| class | SpatialVector |
| This class represents a spatial vector and has 6 elements, with a 3-element rotational vector on top of a 3-element translational vector. More... | |
| class | SpatialVelocity |
| This class represents a spatial velocity V (also called a twist) and has 6 elements with an angular (rotational) velocity ω (3-element vector) on top of a translational (linear) velocity v (3-element vector). More... | |
| class | SpatialVelocityConstraint |
| Constrains the spatial velocity of a frame C, rigidly attached to a frame B, measured and expressed in frame A. More... | |
| class | StaticEquilibriumConstraint |
| Impose the static equilibrium constraint 0 = τ_g + Bu + ∑J_WBᵀ(q) * Fapp_B_W. More... | |
| class | StaticEquilibriumProblem |
| Finds the static equilibrium pose of a multibody system through optimization. More... | |
| class | StaticFrictionConeConstraint |
| Formulates the nonlinear friction cone constraint |fₜ| ≤ μ*fₙ, where fₜ is the tangential contact force, fₙ is the normal contact force, and μ is the friction coefficient. More... | |
| class | TamsiSolver |
| struct | TamsiSolverIterationStats |
| Struct used to store information about the iteration process performed by TamsiSolver. More... | |
| struct | TamsiSolverParameters |
| These are the parameters controlling the iteration process of the TamsiSolver solver. More... | |
| class | Toppra |
| Solves a Time Optimal Path Parameterization based on Reachability Analysis (TOPPRA) to find the fastest traversal of a given path, satisfying the given constraints. More... | |
| class | TriangleQuadrature |
| A class for integrating a function using numerical quadrature over triangular domains. More... | |
| class | TriangleQuadratureRule |
| A "rule" (weights and quadrature points) for computing quadrature over triangular domains. More... | |
| class | UniformGravityFieldElement |
| This ForceElement allows modeling the effect of a uniform gravity field as felt by bodies on the surface of the Earth. More... | |
| class | UnitInertia |
| This class is used to represent rotational inertias for unit mass bodies. More... | |
| class | UnitQuaternionConstraint |
| Constrains the quaternion to have a unit length. More... | |
| class | UniversalJoint |
| This joint models a universal joint allowing two bodies to rotate relative to one another with two degrees of freedom. More... | |
| class | WeldJoint |
| This Joint fixes the relative pose between two frames as if "welding" them together. More... | |
| class | Wing |
| A System that connects to the MultibodyPlant in order to model the simplified dynamics of an airfoil (or hydrofoil). More... | |
Typedefs | |
| using | DeformableBodyId = Identifier< class DeformableBodyTag > |
| Uniquely identifies a deformable body. More... | |
| using | DeformableBodyIndex = TypeSafeIndex< class DeformableBodyTag > |
| (Internal use only) Indexes deformable bodies, only used after Finalize(). More... | |
| template<typename T > | |
| using | PhysicalModelPointerVariant = std::variant< const DeformableModel< T > *, std::monostate > |
| using | FrameIndex = TypeSafeIndex< class FrameTag > |
| Type used to identify frames by index in a multibody plant. More... | |
| using | BodyIndex = TypeSafeIndex< class RigidBodyTag > |
| Type used to identify RigidBodies (a.k.a. More... | |
| using | ForceElementIndex = TypeSafeIndex< class ForceElementTag > |
| Type used to identify force elements by index within a multibody plant. More... | |
| using | JointIndex = TypeSafeIndex< class JointElementTag > |
| Type used to identify joints by index within a multibody plant. More... | |
| using | JointActuatorIndex = TypeSafeIndex< class JointActuatorElementTag > |
| Type used to identify actuators by index within a multibody plant. More... | |
| using | MultibodyConstraintId = Identifier< class ConstraintTag > |
| Type used to identify constraint by id within a multibody plant. More... | |
| using | ModelInstanceIndex = TypeSafeIndex< class ModelInstanceTag > |
| Type used to identify model instances by index within a multibody plant. More... | |
| template<typename T > | |
| using | Body = RigidBody< T > |
| (Compatibility) Prefer RigidBody to Body, however this dispreferred alias is available to permit older code to continue working. More... | |
Enumerations | |
| enum | DifferentialInverseKinematicsStatus { kSolutionFound, kNoSolutionFound, kStuck } |
| enum | ToppraDiscretization { kCollocation, kInterpolation } |
| Selects how linear constraints are enforced for TOPPRA's optimization. More... | |
| enum | ForceDensityType { kPerCurrentVolume, kPerReferenceVolume } |
| (Advanced) Enum for the type of force density in ForceDensityField. More... | |
| enum | ContactModel { kHydroelastic, kPoint, kHydroelasticWithFallback, kHydroelasticsOnly = kHydroelastic, kPointContactOnly = kPoint } |
| Enumeration for contact model options. More... | |
| enum | DiscreteContactSolver { kTamsi, kSap } |
| The type of the contact solver used for a discrete MultibodyPlant model. More... | |
| enum | DiscreteContactApproximation { kTamsi, kSap, kSimilar, kLagged } |
| The type of the contact approximation used for a discrete MultibodyPlant model. More... | |
| enum | BaseBodyJointType { kQuaternionFloatingJoint, kRpyFloatingJoint, kWeldJoint } |
| The kind of joint to be used to connect base bodies to world at Finalize(). More... | |
| enum | TamsiSolverResult { kSuccess = 0, kMaxIterationsReached = 1, kLinearSolverFailed = 2, kAlphaSolverFailed = 3 } |
| The result from TamsiSolver::SolveWithGuess() used to report the success or failure of the solver. More... | |
| enum | JacobianWrtVariable { kQDot, kV } |
| Enumeration that indicates whether the Jacobian is partial differentiation with respect to q̇ (time-derivatives of generalized positions) or with respect to v (generalized velocities). More... | |
Functions | |||||||||||||
| std::vector< solvers::Binding< solvers::Constraint > > | AddMultibodyPlantConstraints (const MultibodyPlant< double > &plant, const solvers::VectorXDecisionVariable &q, solvers::MathematicalProgram *prog, systems::Context< double > *plant_context=nullptr) | ||||||||||||
For unit quaternion and (holonomic) constraints registered with plant adds a corresponding solver::Constraint to prog, using decision variables q to represent the generalized positions of the plant. More... | |||||||||||||
| std::ostream & | operator<< (std::ostream &os, const DifferentialInverseKinematicsStatus value) | ||||||||||||
| Vector6< double > | ComputePoseDiffInCommonFrame (const math::RigidTransform< double > &X_C0, const math::RigidTransform< double > &X_C1) | ||||||||||||
Computes the pose "difference" between X_C0 and X_C1 such that the linear part equals p_C1 - p_C0, and the angular part equals R_C1 * R_C0.inv(), where p and R stand for the position and rotation parts, and C is the common frame. More... | |||||||||||||
| DifferentialInverseKinematicsResult | DoDifferentialInverseKinematics (const Eigen::Ref< const VectorX< double >> &q_current, const Eigen::Ref< const VectorX< double >> &v_current, const Eigen::Ref< const VectorX< double >> &V, const Eigen::Ref< const MatrixX< double >> &J, const DifferentialInverseKinematicsParameters ¶meters, const std::optional< Eigen::Ref< const Eigen::SparseMatrix< double >>> &N=std::nullopt, const std::optional< Eigen::Ref< const Eigen::SparseMatrix< double >>> &Nplus=std::nullopt) | ||||||||||||
| Computes a generalized velocity v_next, via the following MathematicalProgram: More... | |||||||||||||
| DifferentialInverseKinematicsResult | DoDifferentialInverseKinematics (const MultibodyPlant< double > &robot, const systems::Context< double > &context, const Vector6< double > &V_WE_desired, const Frame< double > &frame_E, const DifferentialInverseKinematicsParameters ¶meters) | ||||||||||||
| A wrapper over DoDifferentialInverseKinematics(q_current, v_current, V, J, params) that tracks frame E's spatial velocity. More... | |||||||||||||
| DifferentialInverseKinematicsResult | DoDifferentialInverseKinematics (const MultibodyPlant< double > &robot, const systems::Context< double > &context, const Vector6< double > &V_AE_desired, const Frame< double > &frame_A, const Frame< double > &frame_E, const DifferentialInverseKinematicsParameters ¶meters) | ||||||||||||
| A wrapper over DoDifferentialInverseKinematics(q_current, v_current, V, J, params) that tracks frame E's spatial velocity in frame A. More... | |||||||||||||
| DifferentialInverseKinematicsResult | DoDifferentialInverseKinematics (const MultibodyPlant< double > &robot, const systems::Context< double > &context, const math::RigidTransform< double > &X_WE_desired, const Frame< double > &frame_E, const DifferentialInverseKinematicsParameters ¶meters) | ||||||||||||
| A wrapper over DoDifferentialInverseKinematics(robot, context, V_WE_desired, frame_E, params) that tracks frame E's pose in the world frame. More... | |||||||||||||
| DifferentialInverseKinematicsResult | DoDifferentialInverseKinematics (const MultibodyPlant< double > &robot, const systems::Context< double > &context, const math::RigidTransform< double > &X_AE_desired, const Frame< double > &frame_A, const Frame< double > &frame_E, const DifferentialInverseKinematicsParameters ¶meters) | ||||||||||||
| A wrapper over DoDifferentialInverseKinematics(robot, context, V_AE_desired, frame_A, frame_E, params) that tracks frame E's pose in frame A. More... | |||||||||||||
| template<typename T > | |||||||||||||
| std::vector< solvers::Binding< solvers::Constraint > > | AddUnitQuaternionConstraintOnPlant (const MultibodyPlant< T > &plant, const Eigen::Ref< const VectorX< symbolic::Variable >> &q_vars, solvers::MathematicalProgram *prog) | ||||||||||||
Add unit length constraints to all the variables representing quaternion in q_vars. More... | |||||||||||||
| std::pair< solvers::Binding< internal::SlidingFrictionComplementarityNonlinearConstraint >, solvers::Binding< StaticFrictionConeConstraint > > | AddSlidingFrictionComplementarityExplicitContactConstraint (const ContactWrenchEvaluator *contact_wrench_evaluator, double complementarity_tolerance, const Eigen::Ref< const VectorX< symbolic::Variable >> &q_vars, const Eigen::Ref< const VectorX< symbolic::Variable >> &v_vars, const Eigen::Ref< const VectorX< symbolic::Variable >> &lambda_vars, solvers::MathematicalProgram *prog) | ||||||||||||
| For a pair of geometries in explicit contact, adds the sliding friction complementarity constraint explained in sliding_friction_complementarity_constraint to an optimization program. More... | |||||||||||||
| std::pair< solvers::Binding< internal::SlidingFrictionComplementarityNonlinearConstraint >, solvers::Binding< internal::StaticFrictionConeComplementarityNonlinearConstraint > > | AddSlidingFrictionComplementarityImplicitContactConstraint (const ContactWrenchEvaluator *contact_wrench_evaluator, double complementarity_tolerance, const Eigen::Ref< const VectorX< symbolic::Variable >> &q_vars, const Eigen::Ref< const VectorX< symbolic::Variable >> &v_vars, const Eigen::Ref< const VectorX< symbolic::Variable >> &lambda_vars, solvers::MathematicalProgram *prog) | ||||||||||||
| For a pair of geometries in implicit contact (they may or may not be in contact, adds the sliding friction complementarity constraint explained in sliding_friction_complementarity_constraint. More... | |||||||||||||
| solvers::Binding< internal::StaticFrictionConeComplementarityNonlinearConstraint > | AddStaticFrictionConeComplementarityConstraint (const ContactWrenchEvaluator *contact_wrench_evaluator, double complementarity_tolerance, const Eigen::Ref< const VectorX< symbolic::Variable >> &q_vars, const Eigen::Ref< const VectorX< symbolic::Variable >> &lambda_vars, solvers::MathematicalProgram *prog) | ||||||||||||
| Adds the complementarity constraint on the static friction force between a pair of contacts |ft_W| <= μ * n_Wᵀ * f_W (static friction force in the friction cone). More... | |||||||||||||
| SignedDistanceWithTimeDerivative | CalcDistanceAndTimeDerivative (const multibody::MultibodyPlant< double > &plant, const SortedPair< geometry::GeometryId > &geometry_pair, const systems::Context< double > &context) | ||||||||||||
| Given a pair of geometries and the generalized position/velocity of the plant, compute the signed distance between the pair of geometries and the time derivative of the signed distance. More... | |||||||||||||
| template<typename T > | |||||||||||||
| CoulombFriction< T > | CalcContactFrictionFromSurfaceProperties (const CoulombFriction< T > &surface_properties1, const CoulombFriction< T > &surface_properties2) | ||||||||||||
| Given the surface properties of two different surfaces, this method computes the Coulomb's law coefficients of friction characterizing the interaction by friction of the given surface pair. More... | |||||||||||||
| AddMultibodyPlantSceneGraphResult< double > | AddMultibodyPlant (const MultibodyPlantConfig &config, systems::DiagramBuilder< double > *builder) | ||||||||||||
Adds a new MultibodyPlant and SceneGraph to the given builder. More... | |||||||||||||
| AddMultibodyPlantSceneGraphResult< double > | AddMultibodyPlant (const MultibodyPlantConfig &plant_config, const geometry::SceneGraphConfig &scene_graph_config, systems::DiagramBuilder< double > *builder) | ||||||||||||
Adds a new MultibodyPlant and SceneGraph to the given builder. More... | |||||||||||||
| void | ApplyMultibodyPlantConfig (const MultibodyPlantConfig &config, MultibodyPlant< double > *plant) | ||||||||||||
Applies settings given in config to an existing plant. More... | |||||||||||||
| SpatialInertia< double > | CalcSpatialInertia (const geometry::Shape &shape, double density) | ||||||||||||
Computes the SpatialInertia of a body made up of a homogeneous material (of given density in kg/m³) uniformly distributed in the volume of the given shape. More... | |||||||||||||
| SpatialInertia< double > | CalcSpatialInertia (const geometry::TriangleSurfaceMesh< double > &mesh, double density) | ||||||||||||
Computes the SpatialInertia of a body made up of a homogeneous material (of given density in kg/m³) uniformly distributed in the volume of the given mesh. More... | |||||||||||||
| BodyIndex | world_index () | ||||||||||||
| For every MultibodyPlant the world body always has this unique index and it is always zero. More... | |||||||||||||
| FrameIndex | world_frame_index () | ||||||||||||
| For every MultibodyPlant the world frame always has this unique index and it is always zero. More... | |||||||||||||
| ModelInstanceIndex | world_model_instance () | ||||||||||||
| Returns the model instance containing the world body. More... | |||||||||||||
| ModelInstanceIndex | default_model_instance () | ||||||||||||
| Returns the model instance which contains all tree elements with no explicit model instance specified. More... | |||||||||||||
Visualizing contact results | |||||||||||||
These functions extend a Diagram with the required components to publish contact results (as reported by MultibodyPlant) to a visualizer (Meldis). We recommend using these functions instead of assembling the requisite components by hand. These must be called during Diagram building. Each function makes modifications to the diagram being constructed by
The two overloads differ in the following way:
The parameters have the following semantics:
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| systems::lcm::LcmPublisherSystem * | ConnectContactResultsToDrakeVisualizer (systems::DiagramBuilder< double > *builder, const MultibodyPlant< double > &plant, const geometry::SceneGraph< double > &scene_graph, lcm::DrakeLcmInterface *lcm=nullptr, std::optional< double > publish_period=std::nullopt) | ||||||||||||
| MultibodyPlant-connecting overload. More... | |||||||||||||
| systems::lcm::LcmPublisherSystem * | ConnectContactResultsToDrakeVisualizer (systems::DiagramBuilder< double > *builder, const MultibodyPlant< double > &plant, const geometry::SceneGraph< double > &scene_graph, const systems::OutputPort< double > &contact_results_port, lcm::DrakeLcmInterface *lcm=nullptr, std::optional< double > publish_period=std::nullopt) | ||||||||||||
| OutputPort-connecting overload. More... | |||||||||||||
(Compatibility) Prefer RigidBody to Body, however this dispreferred alias is available to permit older code to continue working.
| using BodyIndex = TypeSafeIndex<class RigidBodyTag> |
Type used to identify RigidBodies (a.k.a.
Links) by index in a multibody plant. Interchangeable with LinkIndex.
| using DeformableBodyId = Identifier<class DeformableBodyTag> |
Uniquely identifies a deformable body.
It is valid before and after Finalize().
| using DeformableBodyIndex = TypeSafeIndex<class DeformableBodyTag> |
(Internal use only) Indexes deformable bodies, only used after Finalize().
| using ForceElementIndex = TypeSafeIndex<class ForceElementTag> |
Type used to identify force elements by index within a multibody plant.
| using FrameIndex = TypeSafeIndex<class FrameTag> |
Type used to identify frames by index in a multibody plant.
| using JointActuatorIndex = TypeSafeIndex<class JointActuatorElementTag> |
Type used to identify actuators by index within a multibody plant.
| using JointIndex = TypeSafeIndex<class JointElementTag> |
Type used to identify joints by index within a multibody plant.
| using ModelInstanceIndex = TypeSafeIndex<class ModelInstanceTag> |
Type used to identify model instances by index within a multibody plant.
| using MultibodyConstraintId = Identifier<class ConstraintTag> |
Type used to identify constraint by id within a multibody plant.
| using PhysicalModelPointerVariant = std::variant<const DeformableModel<T>*, std::monostate> |
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strong |
The kind of joint to be used to connect base bodies to world at Finalize().
See Working with free bodies for definitions and discussion.
| Enumerator | |
|---|---|
| kQuaternionFloatingJoint | 6 dofs, unrestricted orientation. |
| kRpyFloatingJoint | 6 dofs using 3 angles; has singularity. |
| kWeldJoint | 0 dofs, fixed to World. |
|
strong |
Enumeration for contact model options.
| Enumerator | |
|---|---|
| kHydroelastic | Contact forces are computed using the Hydroelastic model. Contact between unsupported geometries will cause a runtime exception. |
| kPoint | Contact forces are computed using a point contact model, see Compliant Point Contact. |
| kHydroelasticWithFallback | Contact forces are computed using the hydroelastic model, where possible. For most other unsupported colliding pairs, the point model from kPoint is used. See geometry::QueryObject::ComputeContactSurfacesWithFallback for more details. |
| kHydroelasticsOnly | Legacy alias. TODO(jwnimmer-tri) Deprecate this constant. |
| kPointContactOnly | Legacy alias. TODO(jwnimmer-tri) Deprecate this constant. |
|
strong |
|
strong |
The type of the contact approximation used for a discrete MultibodyPlant model.
kTamsi, kSimilar and kLagged are all approximations to the same contact model – Compliant contact with regularized friction, refer to Contact Modeling for further details. The key difference however, is that the kSimilar and kLagged approximations are convex and therefore our contact solver has both theoretical and practical convergence guarantees — the solver will always succeed. Conversely, being non-convex, kTamsi can fail to find a solution.
kSap is also a convex model of compliant contact with regularized friction. There are a couple of key differences however:
The Hunt & Crossley model is based on physics, it is continuous and has been experimentally validated. Therefore it is the preferred model to capture the physics of contact.
Being approximations, kSap and kSimilar introduce a spurious effect of "gliding" in sliding contact, see [Castro et al., 2023]. This artifact is 𝒪(δt) but can be significant at large time steps and/or large slip velocities. kLagged does not suffer from this, but introduces a "weak" coupling of friction that can introduce non-negligible effects in the dynamics during impacts or strong transients.
Summarizing, kLagged is the preferred approximation when strong transients are not expected or don't need to be accurately resolved. If strong transients do need to be accurately resolved (unusual for robotics applications), kSimilar is the preferred approximation.
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strong |
The type of the contact solver used for a discrete MultibodyPlant model.
Note: the SAP solver only fully supports scalar type double. For scalar type AutoDiffXd, the SAP solver throws if any constraint (including contact) is detected. As a consequence, one can only run dynamic simulations without any constraints under the combination of SAP and AutoDiffXd. The SAP solver does not support symbolic calculations.
| Enumerator | |
|---|---|
| kTamsi | TAMSI solver, see [Castro et al., 2019]. |
| kSap | SAP solver, see [Castro et al., 2022]. |
|
strong |
(Advanced) Enum for the type of force density in ForceDensityField.
| Enumerator | |
|---|---|
| kPerCurrentVolume | ForceDensityField::EvaluateAt() returns the force per unit of current (deformed) configuration volume. |
| kPerReferenceVolume | ForceDensityField::EvaluateAt() returns the force per unit of reference configuration volume where the reference undeformed configuration is defined by the input mesh provided by the user. |
|
strong |
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The result from TamsiSolver::SolveWithGuess() used to report the success or failure of the solver.
|
strong |
Selects how linear constraints are enforced for TOPPRA's optimization.
kCollocation - enforces constraints only at each gridpoint. kInterpolation - enforces constraints at each gridpoint and at the following gridpoint using forward integration. Yields higher accuracy at minor computational cost.
| Enumerator | |
|---|---|
| kCollocation | |
| kInterpolation | |
| AddMultibodyPlantSceneGraphResult<double> drake::multibody::AddMultibodyPlant | ( | const MultibodyPlantConfig & | config, |
| systems::DiagramBuilder< double > * | builder | ||
| ) |
Adds a new MultibodyPlant and SceneGraph to the given builder.
The plant's settings such as time_step are set using the given config.
| AddMultibodyPlantSceneGraphResult<double> drake::multibody::AddMultibodyPlant | ( | const MultibodyPlantConfig & | plant_config, |
| const geometry::SceneGraphConfig & | scene_graph_config, | ||
| systems::DiagramBuilder< double > * | builder | ||
| ) |
Adds a new MultibodyPlant and SceneGraph to the given builder.
The plant's settings such as time_step are set using the given plant_config. The scene graph's settings are set using the given scene_graph_config.
| std::vector<solvers::Binding<solvers::Constraint> > drake::multibody::AddMultibodyPlantConstraints | ( | const MultibodyPlant< double > & | plant, |
| const solvers::VectorXDecisionVariable & | q, | ||
| solvers::MathematicalProgram * | prog, | ||
| systems::Context< double > * | plant_context = nullptr |
||
| ) |
For unit quaternion and (holonomic) constraints registered with plant adds a corresponding solver::Constraint to prog, using decision variables q to represent the generalized positions of the plant.
Adds constraints for coupler, distance, ball, and weld constraints. The distance constraint is implemented here as a hard kinematic constraint (i.e., d(q) == d₀), instead of a soft "spring" force.
| std::exception | if plant has constraints registered that are not yet supported by this method. |
| std::exception | if prog is nullptr. |
| std::exception | if plant_context is nullptr and one of the MultibodyPlant constraints requires it. (unit quaternion constraints and coupler constraints do not). |
| std::vector<solvers::Binding<solvers::Constraint> > drake::multibody::AddUnitQuaternionConstraintOnPlant | ( | const MultibodyPlant< T > & | plant, |
| const Eigen::Ref< const VectorX< symbolic::Variable >> & | q_vars, | ||
| solvers::MathematicalProgram * | prog | ||
| ) |
Add unit length constraints to all the variables representing quaternion in q_vars.
Namely the quaternions for floating base joints in plant will be enforced to have a unit length.
Additionally, if the initial guess for the quaternion variables has not been set (it is nan), then this method calls MathematicalProgram::SetInitialGuess() with [1, 0, 0, 0], to help the solver avoid singularities.
| plant | The plant on which we impose the unit quaternion constraints. |
| q_vars | The decision variables for the generalized position of the plant. |
| prog | The unit quaternion constraints are added to this prog. |
| T | The scalar type, which must be one of the default scalars. |
| void drake::multibody::ApplyMultibodyPlantConfig | ( | const MultibodyPlantConfig & | config, |
| MultibodyPlant< double > * | plant | ||
| ) |
Applies settings given in config to an existing plant.
The time_step is the one value in config that cannot be updated – it can only be set in the MultibodyPlant constructor. Consider using AddMultibodyPlant() or manually passing config.time_step when you construct the MultibodyPlant.
This method must be called pre-Finalize.
| std::exception | if plant is finalized or if time_step is changed. |
| CoulombFriction<T> drake::multibody::CalcContactFrictionFromSurfaceProperties | ( | const CoulombFriction< T > & | surface_properties1, |
| const CoulombFriction< T > & | surface_properties2 | ||
| ) |
Given the surface properties of two different surfaces, this method computes the Coulomb's law coefficients of friction characterizing the interaction by friction of the given surface pair.
The surface properties are specified by individual Coulomb's law coefficients of friction. As outlined in the class's documentation for CoulombFriction, friction coefficients characterize a surface pair and not individual surfaces. However, we find it useful in practice to associate the abstract idea of friction coefficients to a single surface. Please refer to the documentation for CoulombFriction for details on this topic.
More specifically, this method computes the contact coefficients for the given surface pair as:
μ = 2μₘμₙ/(μₘ + μₙ)
where the operation above is performed separately on the static and dynamic friction coefficients.
| [in] | surface_properties1 | Surface properties for surface 1. Specified as an individual set of Coulomb's law coefficients of friction. |
| [in] | surface_properties2 | Surface properties for surface 2. Specified as an individual set of Coulomb's law coefficients of friction. |
| SignedDistanceWithTimeDerivative drake::multibody::CalcDistanceAndTimeDerivative | ( | const multibody::MultibodyPlant< double > & | plant, |
| const SortedPair< geometry::GeometryId > & | geometry_pair, | ||
| const systems::Context< double > & | context | ||
| ) |
Given a pair of geometries and the generalized position/velocity of the plant, compute the signed distance between the pair of geometries and the time derivative of the signed distance.
This function is similar to QueryObject::ComputeSignedDistancePairClosestPoints(), but it also provides the time derivative of the signed distance.
| plant | The plant on which the geometries are attached. This plant must have been connected to a SceneGraph. | |
| geometry_pair | The pair of geometries whose distance and time derivative are computed. | |
| context | The context of the plant. This must store both q and v. This context must have been extracted from the diagram context which contains both MultibodyPlant and SceneGraph contexts. | |
| [out] | distance | The signed distance between the pair of geometry. |
| [out] | distance_time_derivative | The time derivative of the signed distance. |
| SpatialInertia<double> drake::multibody::CalcSpatialInertia | ( | const geometry::Shape & | shape, |
| double | density | ||
| ) |
Computes the SpatialInertia of a body made up of a homogeneous material (of given density in kg/m³) uniformly distributed in the volume of the given shape.
The shape is defined in its canonical frame S and the body in frame B. The two frames are coincident and aligned (i.e., X_SB = I).
Most shapes are defined such that their center of mass is coincident with So (and, therefore, Bo). These are the shapes that have symmetry across So along each of the axes Sx, Sy, Sz (e.g., geometry::Box, geometry::Sphere, etc.) For meshes, it depends on how the mesh is defined. For more discussion on the nuances of geometry::Mesh and geometry::Convex calculations see below.
| M_BBo_B | The spatial inertia of the hypothetical body implied by the given shape. |
| std::exception | if shape is an instance of geometry::HalfSpace or geometry::MeshcatCone. |
| SpatialInertia<double> drake::multibody::CalcSpatialInertia | ( | const geometry::TriangleSurfaceMesh< double > & | mesh, |
| double | density | ||
| ) |
Computes the SpatialInertia of a body made up of a homogeneous material (of given density in kg/m³) uniformly distributed in the volume of the given mesh.
The mesh is defined in its canonical frame M and the body in frame B. The two frames are coincident and aligned (i.e., X_MB = I).
For the resultant spatial inertia to be meaningful, the mesh must satisfy certain requirements:
Drake currently doesn't validate these requirements on the mesh. Instead, it does a best-faith effort to compute a spatial inertia. For some "bad" meshes, the SpatialInertia will be objectively physically invalid. For others, the SpatialInertia will appear physically valid, but be meaningless because it does not accurately represent the mesh.
| std::exception | if the resulting spatial inertia is obviously physically invalid. See multibody::SpatialInertia::IsPhysicallyValid(). |
| Vector6<double> drake::multibody::ComputePoseDiffInCommonFrame | ( | const math::RigidTransform< double > & | X_C0, |
| const math::RigidTransform< double > & | X_C1 | ||
| ) |
Computes the pose "difference" between X_C0 and X_C1 such that the linear part equals p_C1 - p_C0, and the angular part equals R_C1 * R_C0.inv(), where p and R stand for the position and rotation parts, and C is the common frame.
| ModelInstanceIndex drake::multibody::default_model_instance | ( | ) |
Returns the model instance which contains all tree elements with no explicit model instance specified.
| std::ostream& drake::multibody::operator<< | ( | std::ostream & | os, |
| const DifferentialInverseKinematicsStatus | value | ||
| ) |
| FrameIndex drake::multibody::world_frame_index | ( | ) |
For every MultibodyPlant the world frame always has this unique index and it is always zero.
| BodyIndex drake::multibody::world_index | ( | ) |
For every MultibodyPlant the world body always has this unique index and it is always zero.
| ModelInstanceIndex drake::multibody::world_model_instance | ( | ) |
Returns the model instance containing the world body.
For every MultibodyPlant the world body always has this unique model instance and it is always zero (as described in #3088).