Paparazzi UAS  v7.0_unstable
Paparazzi is a free software Unmanned Aircraft System.
nps_sensor_airspeed.c
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1 /*
2  * Copyright (C) 2014 Felix Ruess <felix.ruess@gmail.com
3  *
4  * This file is part of paparazzi.
5  *
6  * paparazzi is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2, or (at your option)
9  * any later version.
10  *
11  * paparazzi is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with paparazzi; see the file COPYING. If not, write to
18  * the Free Software Foundation, 59 Temple Place - Suite 330,
19  * Boston, MA 02111-1307, USA.
20  */
21 
29 #include "nps_sensor_airspeed.h"
30 
31 #include "generated/airframe.h"
32 
33 #include "std.h"
34 #include "nps_fdm.h"
35 #include "nps_random.h"
36 #include "nps_sensors.h"
37 
39 #ifndef NPS_AIRSPEED_DT
40 #define NPS_AIRSPEED_DT 0.01
41 #endif
42 
44 #ifndef NPS_AIRSPEED_NOISE_STD_DEV
45 #define NPS_AIRSPEED_NOISE_STD_DEV 0.1
46 #endif
47 
48 #ifndef NPS_AIRSPEED_OFFSET
49 #define NPS_AIRSPEED_OFFSET 0
50 #endif
51 
52 
53 void nps_sensor_airspeed_init(struct NpsSensorAirspeed *airspeed, double time)
54 {
55  airspeed->value = 0.;
56  airspeed->offset = NPS_AIRSPEED_OFFSET;
58  airspeed->next_update = time;
59  airspeed->data_available = FALSE;
60 }
61 
62 
63 void nps_sensor_airspeed_run_step(struct NpsSensorAirspeed *airspeed, double time)
64 {
65 
66  if (time < airspeed->next_update) {
67  return;
68  }
69 
70  /* equivalent airspeed + sensor offset */
71  airspeed->value = fdm.airspeed + airspeed->offset;
72  /* add noise with std dev meters/second */
73  airspeed->value += get_gaussian_noise() * airspeed->noise_std_dev;
74  /* can't be negative, min is zero */
75  if (airspeed->value < 0) {
76  airspeed->value = 0.0;
77  }
78 
79  airspeed->next_update += NPS_AIRSPEED_DT;
80  airspeed->data_available = TRUE;
81 }
double airspeed
equivalent airspeed in m/s
Definition: nps_fdm.h:109
struct NpsFdm fdm
Holds all necessary NPS FDM state information.
double get_gaussian_noise(void)
Definition: nps_random.c:109
void nps_sensor_airspeed_init(struct NpsSensorAirspeed *airspeed, double time)
void nps_sensor_airspeed_run_step(struct NpsSensorAirspeed *airspeed, double time)
#define NPS_AIRSPEED_OFFSET
#define NPS_AIRSPEED_NOISE_STD_DEV
standard deviation in meters/second (default 0.1 m/s)
#define NPS_AIRSPEED_DT
10Hz default
Simulated airspeed for NPS simulator.
double offset
offset in meters/second
double value
airspeed reading in meters/second
double noise_std_dev
noise standard deviation
#define TRUE
Definition: std.h:4
#define FALSE
Definition: std.h:5