arl::math::Admittance Class Reference

Integrates the dynamical system for admittance control. More...

#include <autharl_core/math/admittance.h>

Public Types
typedef boost::array< double, 2 >	State
	The type of the state of the dynamical system used by this class. More...

Public Member Functions
	Admittance ()
	~Admittance ()
State	calc (double current_external_force)
	The main function for calculating the next state of the system. More...
void	setParams (double zeta, double ts, double stiffness)
	Sets the parameters (stiffness, damping, inertia) based on desired damping ratio and response time of the system. More...
void	setInitState (const State &x)
	Sets the initial state of the system. Should be called before the control loops starts. More...

Detailed Description

Integrates the dynamical system for admittance control.

Example of use:

Admittance a;

// Design the system
a.setParams(1, 1, 1);

// Read the initial state from the robot (position and velocity)
Admittance::State state = getStateFromRobot();
a.setInitState(init);

// Set the position reference, e.g. the current position of the robot
double reference = getPositionFromRobot();
a.setPositionReference(reference);

// Run the control loop
while(true)
{
  double force = getExternalForceFromRobot();
  state = a.calc(force);
  sendNewStateToTheRobot(state);
}

Member Typedef Documentation

typedef boost::array<double, 2> arl::math::Admittance::State

The type of the state of the dynamical system used by this class.

Constructor & Destructor Documentation

arl::math::Admittance::Admittance

(

)

arl::math::Admittance::~Admittance

(

)

Member Function Documentation

Admittance::State arl::math::Admittance::calc

(

double

current_external_force

)

The main function for calculating the next state of the system.

The function measures the current time by checking when was the last time that someone called it (within a control loop). Then integrates the ODE defined in Admittance::ode function and returns the state in the current time.

Parameters

current_external_force

The current external force

Returns

The state of the system

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void arl::math::Admittance::setInitState

(

const State &

x

)

Sets the initial state of the system. Should be called before the control loops starts.

Parameters

x	The initial state

void arl::math::Admittance::setParams	(	double	zeta,
		double	ts,
		double	stiffness
	)

Sets the parameters (stiffness, damping, inertia) based on desired damping ratio and response time of the system.

Parameters

zeta	The desired damping ratio
ts	The desired response time
stiffness	The desired stiffness