forked from rbmj/612-guillotine
-
Notifications
You must be signed in to change notification settings - Fork 0
/
trajectory.cpp
82 lines (75 loc) · 2.74 KB
/
trajectory.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
/* trajectory.cpp
*
* Copyright (c) 2011, 2012 Chantilly Robotics <[email protected]>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* Implement trajectory calculation algorithms defined in trajectory.h
*/
#include "trajectory.h"
#include <cmath>
using namespace std;
/*
* Some Formulas:
*
* Method one: based on desired angle of entry
*
* alpha = desired angle of entry (positive)
* v_f = velocity of entry
* v_0 = velocity of launch
* g = acceleration due to gravity
* dx = change in x distance
* dy = change in y distance (remember to subtract the height of the turret!)
* theta = angle of launch
*
* g * dx^2
* v_f^2 = ---------------------------------------------
* 2 * (dy + dx * tan alpha) * (cos alpha)^2
*
* [ g * dx ]^2
* v_0^2 = v_f^2 - (2 * g * dx * tan alpha) + [ ------------------- ]
* [ v_f * cos alpha ]
*
* [ (v_f * sin alpha) - (g * dx) / (v_f * cos alpha) ]
* theta = - arctan [ ---------------------------------------------------- ]
* [ v_f * cos alpha ]
*
* Method two: fix launch speed, and just change angle (use last formula above)
*
* Method n: some combination of the above? something completely different?
*
*/
double get_entry_velocity(double alpha, double dy, double dx, double g) {
double num = g * dx * dx;
double denom = cos(alpha);
denom *= denom;
denom *= 2 * (dy + dx * tan(alpha));
return sqrt(num / denom);
}
double get_launch_velocity(double alpha, double dx, double vf, double g) {
double ret = vf;
ret *= vf;
ret -= 2 * g * dx * tan(alpha);
double comp = g * dx;
comp /= vf * cos(alpha);
comp *= comp;
return sqrt(ret + comp);
}
double get_launch_angle(double alpha, double dx, double vf, double g) {
double comp = vf * cos(alpha);
double num = -g * dx;
num /= comp;
num += vf * sin(alpha);
return -(atan2(num, comp));
}