/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Header: FGGain.h
- Author:
- Date started:
+ Author: Jon Berndt
+ Date started: 1998 ?
- ------------- Copyright (C) -------------
+ ------------- Copyright (C) 1998 by Jon S. Berndt, jon@jsbsim.org -------------
This program is free software; you can redistribute it and/or modify it under
- the terms of the GNU General Public License as published by the Free Software
+ the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
- FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
details.
- You should have received a copy of the GNU General Public License along with
+ You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA.
- Further information about the GNU General Public License can also be found on
+ Further information about the GNU Lesser General Public License can also be found on
the world wide web at http://www.gnu.org.
HISTORY
INCLUDES
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
-#ifdef FGFS
-# include <simgear/compiler.h>
-# include STL_STRING
- SG_USING_STD(string);
-#else
-# include <string>
-#endif
-
#include "FGFCSComponent.h"
+#include <string>
#include <input_output/FGXMLElement.h>
#include <math/FGTable.h>
+using std::string;
+
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
DEFINITIONS
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
/** Encapsulates a gain component for the flight control system.
- The gain component merely multiplies the input by a gain. The form of the
- gain component specification is:
- <pre>
- \<component name="name" type="PURE_GAIN">
- \<input> property \</input>
- \<gain> value \</gain>
- [\<output> property \</output>]
- \</component>
- </pre>
- Note: as is the case with the Summer component, the input property name may be
- immediately preceded by a minus sign to invert that signal.
-
- The scheduled gain component multiplies the input by a variable gain that is
+ The gain component merely multiplies the input by a gain. The <b>pure gain</b> form
+ of the component specification is:
+
+ @code
+ <pure_gain name="name">
+ <input> {[-]property} </input>
+ <gain> {property name | value} </gain>
+ [<clipto>
+ <min> {property name | value} </min>
+ <max> {property name | value} </max>
+ </clipto>]
+ [<output> {property} </output>]
+ </pure_gain>
+ @endcode
+
+ Example:
+
+ @code
+ <pure_gain name="Roll AP Wing Leveler">
+ <input>fcs/attitude/sensor/phi-rad</input>
+ <gain>2.0</gain>
+ <clipto>
+ <min>-0.255</min>
+ <max>0.255</max>
+ </clipto>
+ </pure_gain>
+ @endcode
+
+ Note: the input property name may be immediately preceded by a minus sign to
+ invert that signal.
+
+ The <b>scheduled gain</b> component multiplies the input by a variable gain that is
dependent on another property (such as qbar, altitude, etc.). The lookup
mapping is in the form of a table. This kind of component might be used, for
example, in a case where aerosurface deflection must only be commanded to
acceptable settings - i.e at higher qbar the commanded elevator setting might
be attenuated. The form of the scheduled gain component specification is:
- <pre>
- \<COMPONENT NAME="name" TYPE="SCHEDULED_GAIN">
- INPUT \<property>
- [GAIN \<value>]
- SCHEDULED_BY \<property>
- ROWS \<number_of_rows>
- \<lookup_value gain_value>
- ?
- [CLIPTO \<min> \<max> 1]
- [OUTPUT \<property>]
- \</COMPONENT>
- </pre>
+
+ @code
+ <scheduled_gain name="name">
+ <input> {[-]property} </input>
+ <table>
+ <tableData>
+ ...
+ </tableData>
+ </table>
+ [<clipto>
+ <min> {[-]property name | value} </min>
+ <max> {[-]property name | value} </max>
+ </clipto>]
+ [<gain> {property name | value} </gain>]
+ [<output> {property} </output>]
+ </scheduled_gain>
+ @endcode
+
+ Example:
+
+ @code
+ <scheduled_gain name="Scheduled Steer Pos Deg">
+ <input>fcs/steer-cmd-norm</input>
+ <table>
+ <independentVar>velocities/vg-fps</independentVar>
+ <tableData>
+ 10.0 80.0
+ 50.0 15.0
+ 150.0 2.0
+ </tableData>
+ </table>
+ <gain>0.017</gain>
+ <output>fcs/steer-pos-rad</output>
+ </scheduled_gain>
+ @endcode
+
An overall GAIN may be supplied that is multiplicative with the scheduled gain.
- Note: as is the case with the Summer component, the input property name may
- be immediately preceded by a minus sign to invert that signal.
-
- Here is an example of a scheduled gain component specification:
- <pre>
- \<COMPONENT NAME="Pitch Scheduled Gain 1" TYPE="SCHEDULED_GAIN">
- INPUT fcs/pitch-gain-1
- GAIN 0.017
- SCHEDULED_BY fcs/elevator-pos-rad
- ROWS 22
- -0.68 -26.548
- -0.595 -20.513
- -0.51 -15.328
- -0.425 -10.993
- -0.34 -7.508
- -0.255 -4.873
- -0.17 -3.088
- -0.085 -2.153
- 0 -2.068
- 0.085 -2.833
- 0.102 -3.088
- 0.119 -3.377
- 0.136 -3.7
- 0.153 -4.057
- 0.17 -4.448
- 0.187 -4.873
- 0.272 -7.508
- 0.357 -10.993
- 0.442 -15.328
- 0.527 -20.513
- 0.612 -26.548
- 0.697 -33.433
- \</COMPONENT>
- </pre>
- In the example above, we see the utility of the overall GAIN value in
+ Note: the input property name may be immediately preceded by a minus sign to
+ invert that signal.
+
+ In the example above, we see the utility of the overall gain value in
effecting a degrees-to-radians conversion.
- The aerosurface scale component is a modified version of the simple gain
- component. The normal purpose
- for this component is to take control inputs that range from -1 to +1 or
- from 0 to +1 and scale them to match the expected inputs to a flight control
- system. For instance, the normal and expected ability of a pilot to push or
- pull on a control stick is about 50 pounds. The input to the pitch channelb
- lock diagram of a flight control system is in units of pounds. Yet, the
- joystick control input is usually in a range from -1 to +1. The form of the
- aerosurface scaling component specification is:
-<pre>
- \<COMPONENT NAME="name" TYPE="AEROSURFACE_SCALE">
- INPUT \<property>
- MIN \<value>
- MAX \<value>
- [GAIN \<value>]
- [OUTPUT \<property>]
- \</COMPONENT>
-</pre>
- Note: as is the case with the Summer component, the input property name may be
- immediately preceded by a minus sign to invert that signal.
+ The <b>aerosurface scale</b> component is a modified version of the simple gain
+ component. The purpose for this component is to take control inputs from the
+ domain minimum and maximum, as specified (or from -1 to +1 by default) and
+ scale them to map to a specified range. This can be done, for instance, to match
+ the component outputs to the expected inputs to a flight control system.
+
+ The zero_centered element dictates whether the domain-to-range mapping is linear
+ or centered about zero. For example, if zero_centered is false, and if the domain
+ or range is not symmetric about zero, and an input value is zero, the output
+ will not be zero. Let's say that the domain is min=-2 and max=+4, with a range
+ of -1 to +1. If the input is 0.0, then the "normalized" input is calculated to
+ be 33% of the way from the minimum to the maximum. That input would be mapped
+ to an output of -0.33, which is 33% of the way from the range minimum to maximum.
+ If zero_centered is set to true (or 1) then an input of 0.0 will be mapped to an
+ output of 0.0, although if either the domain or range are unsymmetric about
+ 0.0, then the scales for the positive and negative portions of the input domain
+ (above and below 0.0) will be different. The zero_centered element is true by
+ default. Note that this feature may be important for some control surface mappings,
+ where the maximum upper and lower deflections may be different, but where a zero
+ setting is desired to be the "undeflected" value, and where full travel of the
+ stick is desired to cause a full deflection of the control surface.
+
+ The form of the aerosurface scaling component specification is:
+
+ @code
+ <aerosurface_scale name="name">
+ <input> {[-]property name} </input>
+ <domain>
+ <min> {value} </min> <!-- If omitted, default is -1.0 ->
+ <max> {value} </max> <!-- If omitted, default is 1.0 ->
+ </domain>
+ <range>
+ <min> {value} </min> <!-- If omitted, default is 0 ->
+ <max> {value} </max> <!-- If omitted, default is 0 ->
+ </range>
+ <zero_centered< value </zero_centered>
+ [<clipto>
+ <min> {[-]property name | value} </min>
+ <max> {[-]property name | value} </max>
+ </clipto>]
+ [<gain> {property name | value} </gain>]
+ [<output> {property} </output>]
+ </aerosurface_scale>
+ @endcode
+
+ Note: the input property name may be immediately preceded by a minus sign to
+ invert that signal.
+
+ For instance, the normal and expected ability of a
+ pilot to push or pull on a control stick is about 50 pounds. The input to the
+ pitch channel block diagram of a flight control system is often in units of pounds.
+ Yet, the joystick control input usually defines a span from -1 to +1. The aerosurface_scale
+ form of the gain component maps the inputs to the desired output range. The example
+ below shoes a simple aerosurface_scale component that maps the joystick
+ input to a range of +/- 50, which represents pilot stick force in pounds for the F-16.
+
+ @code
+ <aerosurface_scale name="Pilot input">
+ <input>fcs/elevator-cmd-norm</input>
+ <range>
+ <min> -50 </min> <!-- If omitted, default is 0 ->
+ <max> 50 </max> <!-- If omitted, default is 0 ->
+ </range>
+ </aerosurface_scale>
+ @endcode
@author Jon S. Berndt
- @version $Id$
+ @version $Revision$
*/
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
private:
FGTable* Table;
FGPropertyManager* GainPropertyNode;
+ double GainPropertySign;
double Gain;
double InMin, InMax, OutMin, OutMax;
int Rows;
projects / flightgear.git / blobdiff