Template Class DifferentialActionModelContactInvDynamicsTpl

Nested Relationships

Nested Types

Inheritance Relationships

Base Type

Class Documentation

template<typename _Scalar>
class DifferentialActionModelContactInvDynamicsTpl : public crocoddyl::DifferentialActionModelAbstractTpl<_Scalar>

Differential action model for contact inverse dynamics in multibody systems.

This class implements forward kinematic with holonomic contact constraints (defined at the acceleration level) and inverse-dynamics computation using the Recursive Newton Euler Algorithm (RNEA). The stack of cost and constraint functions are implemented in CostModelSumTpl and ConstraintModelManagerTpl, respectively. The acceleration and contact forces are decision variables defined as the control inputs, and the under-actuation and contact constraint are under the name tau and its frame name, thus the user is not allowed to use it.

Additionally, it is important to note that calcDiff() computes the derivatives using the latest stored values by calc(). Thus, we need to first run calc().

Public Types

typedef DifferentialActionModelAbstractTpl<Scalar> Base
typedef DifferentialActionDataContactInvDynamicsTpl<Scalar> Data
typedef StateMultibodyTpl<Scalar> StateMultibody
typedef ActuationModelAbstractTpl<Scalar> ActuationModelAbstract
typedef CostModelSumTpl<Scalar> CostModelSum
typedef ConstraintModelManagerTpl<Scalar> ConstraintModelManager
typedef ContactModelMultipleTpl<Scalar> ContactModelMultiple
typedef DataCollectorAbstractTpl<Scalar> DataCollectorAbstract
typedef DifferentialActionDataAbstractTpl<Scalar> DifferentialActionDataAbstract
typedef ContactItemTpl<Scalar> ContactItem
typedef MathBaseTpl<Scalar> MathBase
typedef MathBase::VectorXs VectorXs
typedef MathBase::MatrixXs MatrixXs

Public Functions

EIGEN_MAKE_ALIGNED_OPERATOR_NEW CROCODDYL_DERIVED_CAST (DifferentialActionModelBase, DifferentialActionModelContactInvDynamicsTpl) typedef _Scalar Scalar
DifferentialActionModelContactInvDynamicsTpl(std::shared_ptr<StateMultibody> state, std::shared_ptr<ActuationModelAbstract> actuation, std::shared_ptr<ContactModelMultiple> contacts, std::shared_ptr<CostModelSum> costs)

Initialize the contact inverse-dynamics action model.

It describes the kinematic evolution of the multibody system with contacts, and computes the needed torques using inverse-dynamics.

Parameters:
  • state[in] State of the multibody system

  • actuation[in] Actuation model

  • contacts[in] Multiple contacts

  • costs[in] Cost model

DifferentialActionModelContactInvDynamicsTpl(std::shared_ptr<StateMultibody> state, std::shared_ptr<ActuationModelAbstract> actuation, std::shared_ptr<ContactModelMultiple> contacts, std::shared_ptr<CostModelSum> costs, std::shared_ptr<ConstraintModelManager> constraints)

Initialize the contact inverse-dynamics action model.

Parameters:
  • state[in] State of the multibody system

  • actuation[in] Actuation model

  • contacts[in] Multiple contacts

  • costs[in] Cost model

  • constraints[in] Constraints model

virtual ~DifferentialActionModelContactInvDynamicsTpl() = default
virtual void calc(const std::shared_ptr<DifferentialActionDataAbstract> &data, const Eigen::Ref<const VectorXs> &x, const Eigen::Ref<const VectorXs> &u) override

Compute the system acceleration, cost value and constraint residuals.

It extracts the acceleration value from control vector and also computes the cost and constraints.

Parameters:
  • data[in] Contact inverse-dynamics data

  • x[in] State point \(\mathbf{x}\in\mathbb{R}^{ndx}\)

  • u[in] Control input \(\mathbf{u}\in\mathbb{R}^{nu}\)

virtual void calc(const std::shared_ptr<DifferentialActionDataAbstract> &data, const Eigen::Ref<const VectorXs> &x) override
virtual void calcDiff(const std::shared_ptr<DifferentialActionDataAbstract> &data, const Eigen::Ref<const VectorXs> &x, const Eigen::Ref<const VectorXs> &u) override

Compute the derivatives of the dynamics, cost and constraint functions.

It computes the partial derivatives of the dynamical system and the cost and contraint functions. It assumes that calc() has been run first. This function builds a quadratic approximation of the time-continuous action model (i.e., dynamical system, cost and constraint functions).

Parameters:
  • data[in] Contact inverse-dynamics data

  • x[in] State point \(\mathbf{x}\in\mathbb{R}^{ndx}\)

  • u[in] Control input \(\mathbf{u}\in\mathbb{R}^{nu}\)

virtual void calcDiff(const std::shared_ptr<DifferentialActionDataAbstract> &data, const Eigen::Ref<const VectorXs> &x) override
virtual std::shared_ptr<DifferentialActionDataAbstract> createData() override

Create the contact inverse-dynamics data.

Returns:

contact inverse-dynamics data

template<typename NewScalar>
DifferentialActionModelContactInvDynamicsTpl<NewScalar> cast() const

Cast the contact-invdyn model to a different scalar type.

It is useful for operations requiring different precision or scalar types.

Template Parameters:

NewScalar – The new scalar type to cast to.

Returns:

DifferentialActionModelContactInvDynamicsTpl<NewScalar> A differential-action model with the new scalar type.

virtual bool checkData(const std::shared_ptr<DifferentialActionDataAbstract> &data) override

Checks that a specific data belongs to the contact inverse-dynamics model.

virtual void quasiStatic(const std::shared_ptr<DifferentialActionDataAbstract> &data, Eigen::Ref<VectorXs> u, const Eigen::Ref<const VectorXs> &x, const std::size_t maxiter = 100, const Scalar tol = Scalar(1e-9)) override

Computes the quasic static commands.

The quasic static commands are the ones produced for a reference posture as an equilibrium point with zero acceleration, i.e., for \(\mathbf{f^q_x}\delta\mathbf{q}+\mathbf{f_u}\delta\mathbf{u}=\mathbf{0}\)

Parameters:
  • data[in] Contact inverse-dynamics data

  • u[out] Quasic-static commands

  • x[in] State point (velocity has to be zero)

  • maxiter[in] Maximum allowed number of iterations (default 100)

  • tol[in] Tolerance (default 1e-9)

virtual std::size_t get_ng() const override

Return the number of inequality constraints.

virtual std::size_t get_nh() const override

Return the number of equality constraints.

virtual std::size_t get_ng_T() const override

Return the number of equality terminal constraints.

virtual std::size_t get_nh_T() const override

Return the number of equality terminal constraints.

virtual const VectorXs &get_g_lb() const override

Return the lower bound of the inequality constraints.

virtual const VectorXs &get_g_ub() const override

Return the upper bound of the inequality constraints.

const std::shared_ptr<ActuationModelAbstract> &get_actuation() const

Return the actuation model.

const std::shared_ptr<ContactModelMultiple> &get_contacts() const

Return the contact model.

const std::shared_ptr<CostModelSum> &get_costs() const

Return the cost model.

const std::shared_ptr<ConstraintModelManager> &get_constraints() const

Return the constraint model manager.

pinocchio::ModelTpl<Scalar> &get_pinocchio() const

Return the Pinocchio model.

virtual void print(std::ostream &os) const override

Print relevant information of the contact inverse-dynamics model.

Parameters:

os[out] Output stream object

Protected Attributes

VectorXs g_lb_

Lower bound of the inequality constraints.

VectorXs g_ub_

< Lower bound of the inequality constraints

std::size_t ng_

< Upper bound of the inequality constraints

std::size_t nh_

< Number of inequality constraints

std::size_t nu_

< Number of equality constraints

std::shared_ptr<StateAbstract> state_

< Control dimension

class ResidualModelActuation : public crocoddyl::ResidualModelAbstractTpl<_Scalar>

Actuation residual.

This residual function enforces the torques of under-actuated joints (e.g., floating-base joints) to be zero. We compute these torques and their derivatives using RNEA inside DifferentialActionModelContactInvDynamicsTpl.

As described in ResidualModelAbstractTpl, the residual value and its Jacobians are calculated by calc and calcDiff, respectively.

Public Types

typedef MathBaseTpl<Scalar> MathBase
typedef ResidualModelAbstractTpl<Scalar> Base
typedef StateMultibodyTpl<Scalar> StateMultibody
typedef ResidualDataAbstractTpl<Scalar> ResidualDataAbstract
typedef DataCollectorAbstractTpl<Scalar> DataCollectorAbstract
typedef MathBase::VectorXs VectorXs

Public Functions

EIGEN_MAKE_ALIGNED_OPERATOR_NEW CROCODDYL_INNER_DERIVED_CAST (ResidualModelBase, DifferentialActionModelContactInvDynamicsTpl, ResidualModelActuation) typedef _Scalar Scalar
inline ResidualModelActuation(std::shared_ptr<StateMultibody> state, const std::size_t nu, const std::size_t nc)

Initialize the actuation residual model.

Parameters:
  • state[in] State of the multibody system

  • nu[in] Dimension of the joint torques

  • nc[in] Dimension of all the contacts

virtual ~ResidualModelActuation() = default
inline virtual void calc(const std::shared_ptr<ResidualDataAbstract> &data, const Eigen::Ref<const VectorXs>&, const Eigen::Ref<const VectorXs>&) override

Compute the actuation residual.

Parameters:
  • data[in] Actuation residual data

  • x[in] State point \(\mathbf{x}\in\mathbb{R}^{ndx}\)

  • u[in] Control input \(\mathbf{u}\in\mathbb{R}^{nv+nu}\)

inline virtual void calc(const std::shared_ptr<ResidualDataAbstract> &data, const Eigen::Ref<const VectorXs>&) override
inline virtual void calcDiff(const std::shared_ptr<ResidualDataAbstract> &data, const Eigen::Ref<const VectorXs>&, const Eigen::Ref<const VectorXs>&) override

Compute the derivatives of the actuation residual.

Parameters:
  • data[in] Actuation residual data

  • x[in] State point \(\mathbf{x}\in\mathbb{R}^{ndx}\)

  • u[in] Control input \(\mathbf{u}\in\mathbb{R}^{nu}\)

inline virtual void calcDiff(const std::shared_ptr<ResidualDataAbstract> &data, const Eigen::Ref<const VectorXs>&) override
inline virtual std::shared_ptr<ResidualDataAbstract> createData(DataCollectorAbstract *const data) override

Create the actuation residual data.

Returns:

Actuation residual data

template<typename NewScalar>
inline DifferentialActionModelContactInvDynamicsTpl<NewScalar>::ResidualModelActuation cast() const

Cast the actuation-residual model to a different scalar type.

It is useful for operations requiring different precision or scalar types.

Template Parameters:

NewScalar – The new scalar type to cast to.

Returns:

DifferentialActionModelContactInvDynamicsTpl<NewScalar>::ResidualModelActuation A residual model with the new scalar type.

inline virtual void print(std::ostream &os) const override

Print relevant information of the actuation residual model.

Parameters:

os[out] Output stream object

Protected Attributes

std::size_t nu_

Control dimension.

std::shared_ptr<StateAbstract> state_

State description.

class ResidualModelContact : public crocoddyl::ResidualModelAbstractTpl<_Scalar>

Contact-acceleration residual.

This residual function is defined as \(\mathbf{r} = \mathbf{a_0}\), where \(\mathbf{a_0}\) defines the desired contact acceleration, which might also include the Baumgarte stabilization gains. Furthermore, the Jacobians of the residual function are computed analytically. This is used by ConstraintModelManagerTpl inside parent DifferentialActionModelContactInvDynamicsTpl class.

As described in ResidualModelAbstractTpl, the residual value and its Jacobians are calculated by calc and calcDiff, respectively.

Public Types

typedef MathBaseTpl<Scalar> MathBase
typedef ResidualModelAbstractTpl<Scalar> Base
typedef StateMultibodyTpl<Scalar> StateMultibody
typedef ResidualDataAbstractTpl<Scalar> ResidualDataAbstract
typedef DataCollectorAbstractTpl<Scalar> DataCollectorAbstract
typedef MathBase::VectorXs VectorXs
typedef MathBase::MatrixXs MatrixXs

Public Functions

EIGEN_MAKE_ALIGNED_OPERATOR_NEW CROCODDYL_INNER_DERIVED_CAST (ResidualModelBase, DifferentialActionModelContactInvDynamicsTpl, ResidualModelContact) typedef _Scalar Scalar
inline ResidualModelContact(std::shared_ptr<StateMultibody> state, const pinocchio::FrameIndex id, const std::size_t nr, const std::size_t nc)

Initialize the contact-acceleration residual model.

Parameters:
  • state[in] State of the multibody system

  • id[in] Contact frame id

  • nr[in] Dimension of the contact-acceleration residual

  • nc[in] Dimension of all contacts

virtual ~ResidualModelContact() = default
inline void calc(const std::shared_ptr<ResidualDataAbstract> &data, const Eigen::Ref<const VectorXs>&, const Eigen::Ref<const VectorXs>&) override

Compute the contact-acceleration residual.

Parameters:
  • data[in] Contact-acceleration residual data

  • x[in] State point \(\mathbf{x}\in\mathbb{R}^{ndx}\)

  • u[in] Control input \(\mathbf{u}\in\mathbb{R}^{nv+nu}\)

inline virtual void calc(const std::shared_ptr<ResidualDataAbstract> &data, const Eigen::Ref<const VectorXs>&) override
inline void calcDiff(const std::shared_ptr<ResidualDataAbstract> &data, const Eigen::Ref<const VectorXs>&, const Eigen::Ref<const VectorXs>&) override

Compute the derivatives of the contact-acceleration residual.

Parameters:
  • data[in] Contact-acceleration residual data

  • x[in] State point \(\mathbf{x}\in\mathbb{R}^{ndx}\)

  • u[in] Control input \(\mathbf{u}\in\mathbb{R}^{nu}\)

inline virtual void calcDiff(const std::shared_ptr<ResidualDataAbstract> &data, const Eigen::Ref<const VectorXs>&) override
inline virtual std::shared_ptr<ResidualDataAbstract> createData(DataCollectorAbstract *const data) override

Create the contact-acceleration residual data.

Returns:

contact-acceleration residual data

template<typename NewScalar>
inline DifferentialActionModelContactInvDynamicsTpl<NewScalar>::ResidualModelContact cast() const

Cast the contact-residual model to a different scalar type.

It is useful for operations requiring different precision or scalar types.

Template Parameters:

NewScalar – The new scalar type to cast to.

Returns:

typename DifferentialActionModelContactInvDynamicsTpl<NewScalar>::ResidualModelContact A residual model with the new scalar type.

inline virtual void print(std::ostream &os) const override

Print relevant information of the contact-acceleration residual model.

Parameters:

os[out] Output stream object

Protected Attributes

std::size_t nr_

Residual vector dimension.

std::size_t nu_

Control dimension.

std::shared_ptr<StateAbstract> state_

State description.