scoutos / scout / libscout / src / LinesensorControl.cpp @ 3a73516c
History | View | Annotate | Download (4 KB)
1 | 1034f829 | Alex | /**
|
---|---|---|---|
2 | * Copyright (c) 2011 Colony Project
|
||
3 | *
|
||
4 | * Permission is hereby granted, free of charge, to any person
|
||
5 | * obtaining a copy of this software and associated documentation
|
||
6 | * files (the "Software"), to deal in the Software without
|
||
7 | * restriction, including without limitation the rights to use,
|
||
8 | * copy, modify, merge, publish, distribute, sublicense, and/or sell
|
||
9 | * copies of the Software, and to permit persons to whom the
|
||
10 | * Software is furnished to do so, subject to the following
|
||
11 | * conditions:
|
||
12 | *
|
||
13 | * The above copyright notice and this permission notice shall be
|
||
14 | * included in all copies or substantial portions of the Software.
|
||
15 | *
|
||
16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
||
17 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
|
||
18 | * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
||
19 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
|
||
20 | * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
|
||
21 | * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
||
22 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
|
||
23 | * OTHER DEALINGS IN THE SOFTWARE.
|
||
24 | */
|
||
25 | |||
26 | /**
|
||
27 | * @file LinesensorControl.cpp
|
||
28 | * @brief Contains line following function implementation
|
||
29 | 3a73516c | Alex | *
|
30 | * @defgroup linesensorcontrol LinesensorControl
|
||
31 | * @brief Functions which a behavior can use to control the line sensor.
|
||
32 | * @ingroup behavior
|
||
33 | 1034f829 | Alex | *
|
34 | * @author Colony Project, CMU Robotics Club
|
||
35 | * @author Alex Zirbel
|
||
36 | 3a73516c | Alex | *
|
37 | * @{
|
||
38 | 1034f829 | Alex | */
|
39 | |||
40 | #include "LinesensorControl.h" |
||
41 | |||
42 | using namespace std; |
||
43 | |||
44 | 5d0687a9 | Priya | static double last_ret; |
45 | |||
46 | 1034f829 | Alex | /**
|
47 | * @brief Initialize the line following module of libscout.
|
||
48 | */
|
||
49 | LinesensorControl::LinesensorControl(const ros::NodeHandle& libscout_node,
|
||
50 | string scoutname)
|
||
51 | : node(libscout_node) |
||
52 | { |
||
53 | query_client = |
||
54 | 6ebee82c | Alex | node.serviceClient< ::messages::query_linesensor>(scoutname+"/query_linesensor");
|
55 | 1034f829 | Alex | } |
56 | |||
57 | /**
|
||
58 | * @brief Returns the current readings of the line follwing sensor.
|
||
59 | */
|
||
60 | 5866cb38 | Alex | vector<uint32_t> LinesensorControl::query() |
61 | 1034f829 | Alex | { |
62 | // Set scan range
|
||
63 | 6ebee82c | Alex | ::messages::query_linesensor srv; |
64 | 1034f829 | Alex | |
65 | if (!query_client.call(srv))
|
||
66 | { |
||
67 | ROS_ERROR("LinesensorControl query failed.");
|
||
68 | } |
||
69 | |||
70 | af7e0f94 | Alex | if (srv.response.readings.size() != 8) |
71 | { |
||
72 | ROS_WARN("Linesensor reading vector has %d readings, 8 expected.",
|
||
73 | int(srv.response.readings.size()));
|
||
74 | } |
||
75 | |||
76 | 5866cb38 | Alex | return srv.response.readings;
|
77 | 1034f829 | Alex | } |
78 | |||
79 | 5d0687a9 | Priya | /**
|
80 | * @brief Returns the average readings of the line following sensors.
|
||
81 | */
|
||
82 | double LinesensorControl::readline()
|
||
83 | { |
||
84 | unsigned int total_read = 0; |
||
85 | unsigned int weighted_total = 0; |
||
86 | |||
87 | vector<uint32_t> readings = query(); |
||
88 | |||
89 | 360e3b6c | Tom Mullins | if (readings.size() < 8) |
90 | { |
||
91 | return last_ret;
|
||
92 | } |
||
93 | |||
94 | 5d0687a9 | Priya | for (int i = 0; i < 8; i++) |
95 | { |
||
96 | total_read += readings[i]; |
||
97 | weighted_total += i * readings[i]; |
||
98 | } |
||
99 | |||
100 | if (total_read == 0) |
||
101 | { |
||
102 | return last_ret;
|
||
103 | } |
||
104 | |||
105 | 6fab3966 | Alex | double ret_val = last_ret = ((double) weighted_total / total_read) - 3.5; |
106 | 5d0687a9 | Priya | return ret_val;
|
107 | } |
||
108 | |||
109 | af7e0f94 | Alex | bool LinesensorControl::fullline(vector<uint32_t> readings)
|
110 | 5d0687a9 | Priya | { |
111 | af7e0f94 | Alex | if (readings.size() < 8) |
112 | { |
||
113 | return false; |
||
114 | } |
||
115 | |||
116 | ae21730e | Priya | for(int i=0; i<8; i++) |
117 | { |
||
118 | if(readings[i] < 200) |
||
119 | return false; |
||
120 | } |
||
121 | return true; |
||
122 | 5d0687a9 | Priya | } |
123 | |||
124 | af7e0f94 | Alex | /**
|
125 | * We define a destination as two gaps of white between the line and patches
|
||
126 | 414d2b48 | Alex | * of 95-shade color (dark grey) on either side.
|
127 | * I use 95-shade color in an attempt to not throw off the line localization.
|
||
128 | af7e0f94 | Alex | */
|
129 | bool LinesensorControl::destination(vector<uint32_t> readings)
|
||
130 | { |
||
131 | if (readings.size() < 8) |
||
132 | { |
||
133 | return false; |
||
134 | } |
||
135 | |||
136 | // Try to match this pattern to what we see
|
||
137 | 414d2b48 | Alex | int expected_pattern[] = {95, 0, 255, 0, 95}; |
138 | af7e0f94 | Alex | int pat_idx = 0; |
139 | |||
140 | for (int i = 0; i < 8; i++) |
||
141 | { |
||
142 | // If the difference between what we have and expect is less than 5
|
||
143 | if (abs(readings[i] - expected_pattern[pat_idx]) < 5) |
||
144 | { |
||
145 | // Check. Keep looking for the rest of the pattern.
|
||
146 | pat_idx++; |
||
147 | } |
||
148 | |||
149 | // The whole pattern was found
|
||
150 | if (pat_idx > 4) |
||
151 | { |
||
152 | return true; |
||
153 | } |
||
154 | } |
||
155 | return false; |
||
156 | } |
||
157 | 3a73516c | Alex | |
158 | /** @} */ |