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incorporate adaptive time step in tumble stepper

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This commit is contained in:
JoePfeiffer 2023-04-21 16:30:49 -06:00
parent dfd7e04db5
commit 4954099b40
2 changed files with 19 additions and 6 deletions
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9
core/src/net/sf/openrocket/simulation/BasicLandingStepper.java
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@ -1,5 +1,8 @@
package net.sf.openrocket.simulation;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import net.sf.openrocket.models.atmosphere.AtmosphericConditions;
import net.sf.openrocket.rocketcomponent.InstanceMap;
import net.sf.openrocket.rocketcomponent.RecoveryDevice;
@ -9,9 +12,6 @@ import net.sf.openrocket.util.GeodeticComputationStrategy;
import net.sf.openrocket.util.MathUtil;
import net.sf.openrocket.util.WorldCoordinate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class BasicLandingStepper extends AbstractSimulationStepper {
private static final Logger log = LoggerFactory.getLogger(BasicLandingStepper.class);
@ -77,8 +77,6 @@ public class BasicLandingStepper extends AbstractSimulationStepper {
Coordinate coriolisAcceleration = status.getSimulationConditions().getGeodeticComputation().getCoriolisAcceleration(
status.getRocketWorldPosition(), status.getRocketVelocity());
linearAcceleration = linearAcceleration.add(coriolisAcceleration);
// Select tentative time step
double timeStep = RECOVERY_TIME_STEP;
@ -88,6 +86,7 @@ public class BasicLandingStepper extends AbstractSimulationStepper {
if (jerk > MathUtil.EPSILON) {
timeStep = Math.min(timeStep, 1.0/jerk);
}
// but don't let it get *too* small
timeStep = Math.max(timeStep, MIN_TIME_STEP);
log.trace("timeStep is " + timeStep);

16
core/src/net/sf/openrocket/simulation/BasicTumbleStepper.java
View File

@ -4,6 +4,9 @@ import java.util.ArrayList;
import java.util.Iterator;
import java.util.Map;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import net.sf.openrocket.rocketcomponent.FinSet;
import net.sf.openrocket.rocketcomponent.FlightConfiguration;
import net.sf.openrocket.rocketcomponent.InstanceContext;
@ -20,6 +23,7 @@ import net.sf.openrocket.util.MathUtil;
import net.sf.openrocket.util.WorldCoordinate;
public class BasicTumbleStepper extends AbstractSimulationStepper {
private static final Logger log = LoggerFactory.getLogger(BasicTumbleStepper.class);
private static final double RECOVERY_TIME_STEP = 0.5;
@ -124,8 +128,18 @@ public class BasicTumbleStepper extends AbstractSimulationStepper {
// Select time step
// Select tentative time step
double timeStep = MathUtil.min(0.5 / linearAcceleration.length(), RECOVERY_TIME_STEP);
// adjust based on change in acceleration (ie jerk)
final double jerk = Math.abs(linearAcceleration.sub(status.getRocketAcceleration()).multiply(1.0/status.getPreviousTimeStep()).length());
if (jerk > MathUtil.EPSILON) {
timeStep = Math.min(timeStep, 1.0/jerk);
}
// but don't let it get *too* small
timeStep = Math.max(timeStep, MIN_TIME_STEP);
log.trace("timeStep is " + timeStep);
// Perform Euler integration
Coordinate newPosition = status.getRocketPosition().add(status.getRocketVelocity().multiply(timeStep)).