📄 gravity.htm
字号:
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2//EN">
<html>
<head>
<link rel="stylesheet" type="text/css" href="fdchelp.css">
<title>
FDC help: Gravity
</title>
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
</head>
<body bgcolor="#DDDDDD"><div>
<h2>
Subsystem <i>Gravity</i>
</h2>
<p><i>Gravity</i> computes the gravitational force components
along the aircraft's body axes. The
acceleration of gravity, <i>g</i>, is extracted from the outputvector of <i><a href="atmosph.htm">Atmosph</a></i>. The outputs from
<i>Gravity</i> are sent to the block <i><a href=
"fmsort.htm">FMsort</a></i>. </p>
<h3>
Inputvectors: <i>x</i> and <i>yatm</i>
</h3>
<pre>
x = [V alpha beta p q r psi theta phi xe ye H]' (states)
yatm = [rho ps T mu g]' (atmospheric properties, computed in
the block <a href=
"atmosph.htm">Atmosph</a>)
{V : airspeed [m/s] }
{alpha: angle of attack [rad] }
{beta : sideslip angle [rad] }
{p : roll rate [rad/s] }
{q : pitch rate [rad/s] }
{r : yaw rate [rad/s] }
{psi : yaw angle [rad] }
theta: pitch angle [rad]
phi : roll angle [rad]
{xe : x-coordinate in Earth-fixed reference frame [m] }
{ye : y-coordinate '' '' '' '' [m] }
{H : altitude above sea-level [m] }
{rho : airdensity [kg/m^3] }
{ps : static pressure [N/m^2] }
{T : temperature [K] }
{mu : dynamic viscosity [kg/(m*s)] }
g : acceleration of gravity [m/s^2]
</pre>
The inputsignals which are not actually used by <i>Gravity</i> have been
put between curly braces.
<h3>
Outputvector: <i>Fgrav</i>
</h3>
<pre>
Fgrav = [Xgr Ygr Zgr]'.
Xgr, Ygr, Zgr: gravity force components along the aircraft's
body-axes [N].
</pre>
<h3>
Parameters to be defined in the Matlab Workspace.
</h3>
<p><i>GM1</i>: vector with some important geometrical properties of the
'Beaver' aircraft, and its mass (which is assumed to be constant
during the motions of interest). Here, the mass <i>m</i> is extracted from
<i>GM1</i>. The vector <i>GM1</i> can be loaded into the workspace from
file by running the utility <i><a href="datload.htm">DATLOAD</a></i>. Run
<i><a href="modbuild.htm">MODBUILD</a></i> first if the datafile does not
yet exist.</p>
</div></body>
</html>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -