jass.contact
Class StickSlip

java.lang.Object
  jass.engine.Out
      jass.contact.StickSlip

All Implemented Interfaces:

Source

public class StickSlip
extends Out

A force model based on stick slip model.

Author:

Kees van den Doel (kvdoel@cs.ubc.ca)

Field Summary

Fields inherited from class jass.engine.Out

buf, bufferSize, bufOld, lock

Constructor Summary

StickSlip(float srate, int bufferSize)
Construct force.

Method Summary

void	computeBuffer() Compute the next buffer.
void	reset() Reset state.
void	setNormalForce(float val) Set normal force magnitude.
void	setSpeed(float v) Set velocity.
void	setStickSlipParameters(float k_damp, float dummy, float mu_static, float mu_dynamic, float v_crit) Set stick-slip model parameters (all in S.I.

Methods inherited from class jass.engine.Out

clearBuffer, copyToOld, getBuffer, getBuffer, getBufferSize, getTime, peekAtBuffer, resetTime, setBufferSize, setTime, setTimeAndNotify

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StickSlip

public StickSlip(float srate,
                 int bufferSize)

Construct force.

Parameters:

srate - sampling rate in Hertz.

bufferSize - bufferSize of this Out.

Method Detail

setStickSlipParameters

public void setStickSlipParameters(float k_damp,
                                   float dummy,
                                   float mu_static,
                                   float mu_dynamic,
                                   float v_crit)

Set stick-slip model parameters (all in S.I. units).

Parameters:

k_damp - damping of spring system

dummy - not used

mu_static - static friction coeff

mu_dynamic - dynamic friction coeff

v_crit - critical velocity for transition from dyn. to static friction

setNormalForce

public void setNormalForce(float val)

Set normal force magnitude.

Parameters:

val - normal force in Newton

setSpeed

public void setSpeed(float v)

Set velocity.

Parameters:

v - velocity in m/s

reset

public void reset()

Reset state.

computeBuffer

public void computeBuffer()

Compute the next buffer. q(t+1) = (1-k_damp)q(t)+fn mu[(v - (q(t)-q(t-1)))] * sign(v - (q(t)-q(t-1))

Specified by:

computeBuffer in class Out