Class LoopConstraintConVel

• Defined in File LoopConstraintBase.h

Inheritance Relationships

Base Type

• public Karana::Dynamics::LoopConstraintBase (Class LoopConstraintBase)

Class Documentation

class LoopConstraintConVel : public Karana::Dynamics::LoopConstraintBase

Class for constant velocity loop constraints.

This constraint requires that a component of the relative angular/linear velocity of a pair of body constraint nodes projected onto a unit axis be equal. This constraint only applies at the velocity and acceleration levels, and not the positional level.

See the Convel loop-constraints section for more discussion on convel loop constraints.

Public Functions

LoopConstraintConVel(kc::ks_ptr<Multibody> &mb, kc::ks_ptr<kf::FrameToFrame> constraint_f2f, std::string_view name)

Constructor.

Parameters:

• mb – The Multibody instance

• constraint_f2f – the Karana::Frame::FrameToFrame defining the constrained Frame pair

• name – the name for the loop constraint instance

inline virtual std::string_view typeString() const noexcept override

Returns the type string of Base.

Returns:

The type string.

inline virtual bool constrainsQ() const override

convel constraints only impact velocities

virtual size_t nResiduals() const override

Return the size of residuals for the constraint.

Returns:

the residuals size for the constraint

virtual km::Vec poseError() const override

Return the 6 size pose residual term for the constraint.

Used for computing the pose configuration kinematics

Returns:

The pose error

void setInput(double vel, double accel)

Set the velocity and acceleration inputs for the convel constraint.

The input is used to set the difference between the source and target component velocity and acceleration component values.

Parameters:

• vel – The input velocity

• accel – The input accel

void setUnitAxis(const km::Vec &axis, bool is_rotational)

Set the unit axis long which the convel constraint applies.

Parameters:

• axis – The unit axis vector in the source node frame

• is_rotational – If true, the constraint is assumed to on relative angular velocity, else translational

const km::Vec3 &getUnitAxis() const

Get the unit axis to which the convel constraint applies.

Returns:

The unit axis vector in the source node frame

bool isRotational() const

Get whether the constraint is on relative angular velocity.

Returns:

If the constraint is angular, else linear

virtual bool isFinalized() const override

Checks is the params for the object have been initialized.

Returns:

True if the params have set up.

virtual km::Vec velError() const override

Return the current constraint spatial velocity error.

Returns:

the spatial velocity error as a 6-vector

virtual km::Vec accelError() const override

Return the current constraint spatial acceleration error.

Returns:

the acceleration error

Public Static Functions

static const kc::ks_ptr<LoopConstraintConVel> create(kc::ks_ptr<Multibody> &mb, kc::ks_ptr<kf::FrameToFrame> constraint_f_to_f, std::string_view name)

Factory method for creating a LoopConstraintConVel instance.

Parameters:

• mb – The Multibody instance

• constraint_f_to_f – the Karana::Frame::FrameToFrame defining the constrained Frame pair

• name – the name for the loop constraint instance

Returns:

a LoopConstraintHinge instance

Protected Functions

virtual void _computeQMats(QMats &val) override

virtual km::Vec _accelResidual() const override

Return the (6-nU) size accel residual term for the constraint.

Used for computing the lambda (Lagrange multiplier) terms for the TA dynamics correction step

Returns:

The acceleration residual error