Template Class DifferentialActionModelFreeFwdDynamicsTpl

Defined in File free-fwddyn.hpp

Inheritance Relationships

Base Type

public crocoddyl::DifferentialActionModelAbstractTpl< _Scalar > (Template Class DifferentialActionModelAbstractTpl)

Class Documentation

template<typename _Scalar> class DifferentialActionModelFreeFwdDynamicsTpl : public crocoddyl::DifferentialActionModelAbstractTpl<_Scalar>

Differential action model for free forward dynamics in multibody systems.

This class implements free forward dynamics, i.e.,

\[ \mathbf{M}\dot{\mathbf{v}} + \mathbf{h}(\mathbf{q},\mathbf{v}) = \boldsymbol{\tau}, \]

where \(\mathbf{q}\in Q\), \(\mathbf{v}\in\mathbb{R}^{nv}\) are the configuration point and generalized velocity (its tangent vector), respectively; \(\boldsymbol{\tau}\) is the torque inputs and \(\mathbf{h}(\mathbf{q},\mathbf{v})\) are the Coriolis effect and gravity field.

The derivatives of the system acceleration is computed efficiently based on the analytical derivatives of Articulate Body Algorithm (ABA) as described in carpentier-rss18.

The stack of cost functions is implemented in CostModelSumTpl. The computation of the free forward dynamics and its derivatives are carrying out inside calc() and calcDiff() functions, respectively. It is also important to remark that calcDiff() computes the derivatives using the latest stored values by calc(). Thus, we need to run calc() first.