2015.1 Release Notes
New features in Version 2015.1 include:
All toolboxes have been updated to handle the new graphics engine in R2014b. Graphics handles are now a unique type of object, and must be preallocated with a special function. In addition, the zbuffer renderer is no longer supported, so all graphics use the OpenGL renderer.
Our new Missions module gives you several different missions from which you can start your own designs! These are:
LunarLanderCAD- design a lunar spacecraft!
LunarMissionDesign- designs lunar mission from LEO to the lunar surface
LunarLanderThrusterLayout- layout the ACS thrusters for a lunar landing spacecraft
LunarMissionSim- simulates a lunar mission from LEO to the lunar surface
OrvMnvrLowerApogee- Simple function to compute apogee lowering maneuvers
OrbMnvrInsertion- planetary insertion maneuvers
OrbitDrag- compute drag losses on an orbit
RHSOptimalFPA- compute the optimal flight path angle for stage separation
PatchedConicPlanner- designing trajectories with patched conics
TrajectoryPlot- plot trajectories in 3 dimensions
WalkerConstellation- compute orbital elements for a Walker rosette or star
BremsstrahlungWavelength- computes the wavelength of bremsstrahlung radiation from a fusion reactor
XRayMassCoeff- computes the attenuation mass and absorption mass for a material.
MagneticFieldCurrentLoop- helps design magnetic nozzles and other magnet systems
RHSSpacecraftWithRWA- new easy to use function for spacecraft with wheels
SpacecraftWithRWADemo- demo of the new model with disturbance torques
ExportDXF- export CAD models in dxf format that is readable by all CAD products such as SolidWorks
DisplayLatexTable- displays a table formatted for the Latex document generation language
RocketH2O2- model cryogenic rocket engines including pre-heat.
SonicBoomHypersonic- compute sonic booms
StagnationPAndT- compute stagnation conditions in atmospheric flight
TurboRamRocket- combined cycle engine for next generation launch vehicles
RHSSpacecraftWithRWA.m is a new right-hand-side for spacecraft with reaction wheels. It makes it easier than ever to model reaction wheel controlled spacecraft. It includes Coulomb and viscous friction which can be specified per wheel, a simple gravity model and quaternion kinematics. A new demo,
SpacecraftWithRWADemo, shows how to use it with
PID3Axis.m. You can test the controller with various wheel parameters, disturbance torques, and initial wheel and body rates. Consider an example with an initial body rate around x, a steady disturbance torque of 1e-4 Nm around y,
and a goal of returning to a nominal quaternion. The first set of figures show the controller response with no friction or damping. The body rates return to zero and the wheel torque matches the input disturbance torque.
|Body rates, no damping or friction||Wheel torques|
The next set of figures shows the response with a wheel damping coefficient of 5e-6 Nms, typical for CubeSat wheels. Note that the addition of damping, which is proportional to wheel speed, turns our steady disturbance torque into a ramp. This results in an attitude offset.
|Body rates look the same with damping||Total disturbance is now a ramp due to damping|
The final set of figures shows the response with a Coulomb friction torque of 1e-3 Nm. This causes limit cycling in the wheel speed around zero, leading to oscillations in the body rates. The friction torque in this case is larger than the disturbance torque!
|Body rates with influence of Coulomb friction||Wheel torques|
A new constellation design function enables you to produce Keplerian elements for any number of satellites in a Walker Delta or Star constellation.
LunarMissionSim demo computes a transfer orbit between LEO and the moon, calculated a delta-V for the lunar orbit injection, and simulates the final orbit to show that the insertion worked as expected. This uses the new maneuver function
LunarMissionDesign plans a complete mission from LEO to lunar landing, calculating all the delta-V magnitudes and simulating a powered landing using
BilinearTangent. The script generates plots and a table with the results, copied below.
A new folder called SCModels has been added to SC/, for stored versions of CAD models, to separate them from other data files.
A Missions/ module was added with folders for AlphaCentauri, AsteroidProspector, Comsat attitude control, FastReorientation, LunarMission, and SunNadir. This replaces the AttitudeControl/ module.
A Constellations folder was added to Orbit for the
The magnetic control functions were consolidated into a new MagneticControl folder in SC/.
The following sections list those functions which have been added or relocated since Version 2014.1.
The following functions were relocated from the AttitudeControl module.SC/Demos/MagneticControl/MagControl.m