com.ur.urcap.api.domain.value.dynamics

Interface InertiaMatrix

public interface InertiaMatrix

This interface represents the inertia matrix for an object, e.g. a payload. The inertia matrix is sometimes referred to as the inertia tensor.

For a payload, the inertia matrix is defined in a coordinate system with center at the payload's center of gravity (CoG), also referred to as center of mass, and the axes aligned with the tool output flange coordinate system (axes). The center of gravity is defined as the offset between the center of the tool output flange and the center of gravity of the attached payload.

The inertia matrix is formally a 3x3 symmetric matrix containing the moments of inertia and products of inertia around all three Cartesian axes for an object:

  Ixx  Ixy  Ixz
  Ixy  Iyy  Iyz
  Ixz  Iyz  Izz
 

Since the inertia matrix is symmetric, it is only represented by six component values, i.e. the three moments of inertia (Ixx, Iyy, Izz) and the three products of inertia (Ixy, Ixz, Iyz).

Since:

1.13.0

Method Summary

Modifier and Type	Method and Description
boolean	epsilonEquals(InertiaMatrix other, double epsilon, MomentOfInertia.Unit unit) Indicates whether some other InertiaMatrix object is "approximately equal" to this one.
boolean	equals(Object obj) Indicates whether some other InertiaMatrix object is "equal to" this one.
double[]	getComponents(MomentOfInertia.Unit unit) Provides the six unique components of the inertia matrix, i.e.
double	getIxxComponent(MomentOfInertia.Unit unit) Provides the Ixx component of the inertia matrix, i.e.
double	getIxyComponent(MomentOfInertia.Unit unit) Provides the Ixy component of the inertia matrix, i.e.
double	getIxzComponent(MomentOfInertia.Unit unit) Provides the Ixz component of the inertia matrix, i.e.
double	getIyyComponent(MomentOfInertia.Unit unit) Provides the Iyy component of the inertia matrix, i.e.
double	getIyzComponent(MomentOfInertia.Unit unit) Provides the Iyz component of the inertia matrix, i.e.
double	getIzzComponent(MomentOfInertia.Unit unit) Provides the Izz component of the inertia matrix, i.e.
int	hashCode()
String	toString()

Method Detail

getIxxComponent

double getIxxComponent(MomentOfInertia.Unit unit)

Provides the Ixx component of the inertia matrix, i.e. the moment of inertia around the x-axis.

Parameters:

unit - The unit for which to return the moment of inertia value

Returns:

The moment of inertia around the x-axis in specified units

getIyyComponent

double getIyyComponent(MomentOfInertia.Unit unit)

Provides the Iyy component of the inertia matrix, i.e. the moment of inertia around the y-axis.

Parameters:

unit - The unit for which to return the moment of inertia value

Returns:

The moment of inertia value around the y-axis in specified units

getIzzComponent

double getIzzComponent(MomentOfInertia.Unit unit)

Provides the Izz component of the inertia matrix, i.e. the moment of inertia around the z-axis

Parameters:

unit - The unit for which to return the moment of inertia value

Returns:

the moment of inertia value around the z-axis in specified units

getIxyComponent

double getIxyComponent(MomentOfInertia.Unit unit)

Provides the Ixy component of the inertia matrix, i.e. the product of inertia around the x and y axes

Parameters:

unit - The unit for which to return the product of inertia value

Returns:

The product of inertia value around the x and y axes in specified units

getIxzComponent

double getIxzComponent(MomentOfInertia.Unit unit)

Provides the Ixz component of the inertia matrix, i.e. the product of inertia around the x and z axes

Parameters:

unit - The unit for which to return the product of inertia value

Returns:

The product of inertia value for around x and z axes in specified units

getIyzComponent

double getIyzComponent(MomentOfInertia.Unit unit)

Provides the Iyz component of the inertia matrix, i.e. the product of inertia around the y and z axes

Parameters:

unit - The unit for which to return the product of inertia value

Returns:

The product of inertia value for around y and z axes in specified units

getComponents

double[] getComponents(MomentOfInertia.Unit unit)

Provides the six unique components of the inertia matrix, i.e. the three values for the moments of inertia and the three values for the products of inertia. The six components are returned as an array with elements in the following order: Ixx, Iyy, Izz, Ixy, Ixz, Iyz.

Parameters:

unit - The unit for which to return the values for the moments of inertia and products of inertia

Returns:

A double array with the moments of inertia and products of inertia values in the specified units

hashCode

int hashCode()

Overrides:

hashCode in class Object

Returns:

A hash code value for this object.

equals

boolean equals(Object obj)

Indicates whether some other InertiaMatrix object is "equal to" this one.

Overrides:

equals in class Object

Parameters:

obj - Another InertiaMatrix object.

Returns:

true if the values of this InertiaMatrix instance and the obj argument are exactly the same; otherwise false.

epsilonEquals

boolean epsilonEquals(InertiaMatrix other,
                      double epsilon,
                      MomentOfInertia.Unit unit)

Indicates whether some other InertiaMatrix object is "approximately equal" to this one.

Two inertia matrices are considered "approximately equal", if all the absolute differences between corresponding component values of the two matrices are less than or equal to the specified tolerance. The distance metric used is the L-infinite metric (also called the maximum metric) with the equality criterion defined in the form of MAX( abs(Ixx1-Ixx2), abs(Iyy1-Iyy2), abs(Izz1-Izz2), abs(Ixy1-Ixy2), abs(Ixz1-Ixz2), abs(Iyz1-Iyz2) ) <= epsilon.

Parameters:

other - Another InertiaMatrix object.

epsilon - The tolerance value to be used for the comparison of inertia matrix components (i.e. Ixx, Iyy, ...) in specified units

unit - The unit for the specified epsilon tolerance.

Returns:

true if the values of this object is "approximately equal" to the values of the other argument; false otherwise.

toString

String toString()

Overrides:

toString in class Object

Returns:

A string representation of the inertia matrix, i.e. the Ixx, Iyy, Izz, Ixy, Ixz and Iyz components.