MassDamperSpringAnalyticalSolution< T > Class Template Reference

Detailed Description

template<typename T>
class drake::multibody::benchmarks::MassDamperSpringAnalyticalSolution< T >

This class provides an analytical solution to a mass-damper-spring system.

The system consists of a particle Q of mass m that can only move left/right on flat Earth (frame N). Particle Q is connected by an ideal translational spring/damper. The other end of the spring/damper is welded to point No (the origin of frame N). Q's position from No is x*Nx where x(t) is a time- dependent variable (to-be-calculated) and Nx is a horizontal unit vector fixed in Earth (N). The spring force on Q is -k*x*Nx, where k is a spring constant. The damper force on Q is -b*ẋ*Nx where b is a damper constant and ẋ is the time-derivative of x.

Note

All units must be self-consistent (e.g., standard SI with MKS units). The solution provided herein is also applicable to a rotating system, e.g., having rigid-body inertia, rotational damper, rotational spring.

Template Parameters

T	The scalar type, which must be one of the default nonsymbolic scalars.

#include <drake/multibody/benchmarks/mass_damper_spring/mass_damper_spring_analytical_solution.h>

Public Member Functions
	MassDamperSpringAnalyticalSolution (const T &mass, const T &b, const T &k)
	This constructs the aforementioned mass-damper-spring system. More...
void	SetInitialValue (const T &x0, const T &xDt0)
	Sets the initial values of x and ẋ for this system. More...
Vector3< T >	CalculateOutput (const T &t) const
	For this mass-damper-spring system, and with the given initial values, this method calculates the values of x, ẋ, ẍ at time t. More...
T	get_x (const T &t) const
	Returns x (Nx measure of Q's position from No) at time t. More...
T	get_xDt (const T &t) const
	Returns ẋ (Nx measure of Q's velocity in N) at time t. More...
T	get_xDtDt (const T &t) const
	Returns ẍ (Nx measure of Q's acceleration in N) at time t. More...
Does not allow copy, move, or assignment
	MassDamperSpringAnalyticalSolution (const MassDamperSpringAnalyticalSolution &)=delete
MassDamperSpringAnalyticalSolution &	operator= (const MassDamperSpringAnalyticalSolution &)=delete
	MassDamperSpringAnalyticalSolution (MassDamperSpringAnalyticalSolution &&)=delete
MassDamperSpringAnalyticalSolution &	operator= (MassDamperSpringAnalyticalSolution &&)=delete

Constructor & Destructor Documentation

MassDamperSpringAnalyticalSolution() [1/3]

MassDamperSpringAnalyticalSolution ( const MassDamperSpringAnalyticalSolution< T > &  )

delete

MassDamperSpringAnalyticalSolution() [2/3]

MassDamperSpringAnalyticalSolution ( MassDamperSpringAnalyticalSolution< T > &&  )

delete

MassDamperSpringAnalyticalSolution() [3/3]

MassDamperSpringAnalyticalSolution	(	const T &	mass,
		const T &	b,
		const T &	k
	)

This constructs the aforementioned mass-damper-spring system.

Parameters

[in]	mass	Mass of system (particle Q).
[in]	b	Linear damping constant.
[in]	k	Linear spring constant.

Member Function Documentation

CalculateOutput()

Vector3<T> CalculateOutput

(

const T &

t

)

const

For this mass-damper-spring system, and with the given initial values, this method calculates the values of x, ẋ, ẍ at time t.

Parameters

[in]

t

The value of time at which output is requested.

Returns

Three-element matrix consisting of x, ẋ, ẍ, respectively.

get_x()

T get_x

(

const T &

t

)

const

Returns x (Nx measure of Q's position from No) at time t.

get_xDt()

T get_xDt

(

const T &

t

)

const

Returns ẋ (Nx measure of Q's velocity in N) at time t.

get_xDtDt()

T get_xDtDt

(

const T &

t

)

const

Returns ẍ (Nx measure of Q's acceleration in N) at time t.

operator=() [1/2]

MassDamperSpringAnalyticalSolution& operator= ( MassDamperSpringAnalyticalSolution< T > &&  )

delete

operator=() [2/2]

MassDamperSpringAnalyticalSolution& operator= ( const MassDamperSpringAnalyticalSolution< T > &  )

delete

SetInitialValue()

void SetInitialValue	(	const T &	x0,
		const T &	xDt0
	)

Sets the initial values of x and ẋ for this system.

Parameters

[in]	x0	Initial value of x (value of x at time t = 0).
[in]	xDt0	Initial value of ẋ (value of ẋ at time t = 0).

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The documentation for this class was generated from the following file:

• drake/multibody/benchmarks/mass_damper_spring/mass_damper_spring_analytical_solution.h