root / scout / motors / src / motors.cpp @ 3ec16d35
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1 | c406f16b | Ben | /**
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2 | 0121ead7 | bwasserm | * Copyright (c) 2011 Colony Project
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3 | c406f16b | Ben | *
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4 | * Permission is hereby granted, free of charge, to any person
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5 | * obtaining a copy of this software and associated documentation
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6 | * files (the "Software"), to deal in the Software without
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7 | * restriction, including without limitation the rights to use,
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8 | * copy, modify, merge, publish, distribute, sublicense, and/or sell
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9 | * copies of the Software, and to permit persons to whom the
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10 | * Software is furnished to do so, subject to the following
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11 | * conditions:
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12 | *
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13 | * The above copyright notice and this permission notice shall be
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14 | * included in all copies or substantial portions of the Software.
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15 | *
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16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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17 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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18 | * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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19 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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20 | * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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21 | * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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22 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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23 | * OTHER DEALINGS IN THE SOFTWARE.
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24 | **/
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25 | |||
26 | /**
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27 | * @file motors.cpp
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28 | 18e2028b | Alex | * @brief Contains code to control the motors.
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29 | c406f16b | Ben | *
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30 | * Implementation of functions for motor use.
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31 | *
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32 | * @author Colony Project, CMU Robotics Club
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33 | 3ec16d35 | Ben Wasserman | * @author Ben Wasserman
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34 | c406f16b | Ben | **/
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35 | |||
36 | #include "ros/ros.h" |
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37 | #include "motors.h" |
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38 | 0121ead7 | bwasserm | //#include "libscout/src/constants.h"
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39 | c406f16b | Ben | #include <cstdlib> |
40 | |||
41 | /**
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42 | * @defgroup motors Motors
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43 | * @brief Functions for using the motors
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44 | *
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45 | 18e2028b | Alex | * @{
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46 | c406f16b | Ben | **/
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47 | |||
48 | c9f87aaf | bwasserm | /* Motor state variables
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49 | * Speeds expressed as absolute speed out of max speed (0 - +-MAXSPEED)
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50 | * Absolute speed is the speed written to the hardware to move the motors
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51 | */
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52 | 18e2028b | Alex | /** @todo Fix types: static */
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53 | 0121ead7 | bwasserm | int motor_fl_speed; /**< The current speed of the front left motor. */ |
54 | int motor_fr_speed; /**< The current speed of the front right motor. */ |
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55 | int motor_bl_speed; /**< The current speed of the back left motor. */ |
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56 | int motor_br_speed; /**< The current speed of the back right motor. */ |
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57 | |||
58 | 18e2028b | Alex | /**
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59 | * @brief Sets motor speed
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60 | c406f16b | Ben | *
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61 | * Sets the motor speeds based on subscription to the set_motors topic.
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62 | *
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63 | 18e2028b | Alex | * @param msg The message from the set_motors topic, containing speeds and
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64 | c406f16b | Ben | * motor configuration settings.
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65 | */
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66 | 18e2028b | Alex | void motors_set(const motors::set_motors::ConstPtr& msg) |
67 | { |
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68 | c9f87aaf | bwasserm | /** @todo Edit to only set requested motors, not all */
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69 | int which = msg->which;
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70 | if(which & MOTOR_FL_REV)
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71 | { |
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72 | motor_fl_speed = -1 * motors_rel_to_abs(msg->fl_speed, msg->units);
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73 | } |
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74 | if(which & MOTOR_FR_REV)
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75 | { |
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76 | motor_fr_speed = -1 * motors_rel_to_abs(msg->fr_speed, msg->units);
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77 | } |
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78 | if(which & MOTOR_BL_REV)
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79 | { |
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80 | motor_bl_speed = -1 * motors_rel_to_abs(msg->bl_speed, msg->units);
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81 | } |
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82 | if(which & MOTOR_BR_REV)
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83 | { |
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84 | motor_br_speed = -1 * motors_rel_to_abs(msg->br_speed, msg->units);
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85 | } |
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86 | if(which & MOTOR_FL)
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87 | { |
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88 | motor_fl_speed = motors_rel_to_abs(msg->fl_speed, msg->units); |
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89 | } |
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90 | if(which & MOTOR_FR)
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91 | { |
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92 | motor_fr_speed = motors_rel_to_abs(msg->fr_speed, msg->units); |
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93 | } |
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94 | if(which & MOTOR_BL)
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95 | { |
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96 | motor_bl_speed = motors_rel_to_abs(msg->bl_speed, msg->units); |
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97 | } |
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98 | if(which & MOTOR_BR)
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99 | { |
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100 | motor_br_speed = motors_rel_to_abs(msg->br_speed, msg->units); |
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101 | } |
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102 | |||
103 | /* Write speeds to hardware */
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104 | /** @todo Add code to write speeds to hardware */
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105 | c406f16b | Ben | } |
106 | |||
107 | 18e2028b | Alex | /**
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108 | * @brief Outputs current motor speeds
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109 | c406f16b | Ben | *
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110 | * Serves the service query_motors by responding to service requests with the
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111 | * speeds of the motors.
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112 | c9f87aaf | bwasserm | * @param req The request. The only field is the units requested.
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113 | 18e2028b | Alex | * @param res The response. The fields will be filled with values.
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114 | c406f16b | Ben | */
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115 | bool motors_query(motors::query_motors::Request &req,
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116 | 18e2028b | Alex | motors::query_motors::Response &res) |
117 | { |
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118 | c9f87aaf | bwasserm | int units = req.units;
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119 | res.fl_speed = motors_abs_to_rel(motor_fl_speed, units); |
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120 | res.fr_speed = motors_abs_to_rel(motor_fr_speed, units); |
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121 | res.bl_speed = motors_abs_to_rel(motor_bl_speed, units); |
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122 | res.br_speed = motors_abs_to_rel(motor_br_speed, units); |
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123 | 18e2028b | Alex | |
124 | ROS_DEBUG("Motor speeds queried");
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125 | return true; |
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126 | } |
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127 | |||
128 | /**
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129 | c9f87aaf | bwasserm | * @brief Converts set speeds (of various units) to absolute speeds.
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130 | *
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131 | * @param speed The speed expressed in the desired units
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132 | * @param units The units the desired speed is measured in
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133 | * @return The absolute speed of the motor
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134 | **/
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135 | int motors_rel_to_abs(int rel_speed, int units) |
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136 | { |
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137 | switch(units)
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138 | { |
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139 | case MOTOR_ABSOLUTE:/* Speed given as absolute */ |
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140 | return rel_speed;
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141 | case MOTOR_PERCENT:/* Convert from percentage */ |
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142 | return rel_speed * MAXSPEED / 100; |
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143 | case MOTOR_MMS:/* Convert from mm/s */ |
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144 | /** @todo Make math to do this conversion **/
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145 | return rel_speed;
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146 | case MOTOR_CMS:/* Convert from cm/s */ |
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147 | /** @todo Make math to do this conversion **/
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148 | return rel_speed;
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149 | default: /* The units aren't recognized */ |
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150 | /** @todo Decide on default case. Either percent or absolute. **/
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151 | return rel_speed;
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152 | } |
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153 | } |
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154 | |||
155 | /**
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156 | * @brief Convert absolute speeds to speeds of various units.
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157 | *
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158 | * @param speed The speed expressed in absolute units.
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159 | * @param units The units the desired speed is measured in.
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160 | * @return The relative speed of the motor in desired units.
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161 | **/
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162 | int motors_abs_to_rel(int abs_speed, int units) |
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163 | { |
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164 | switch(units)
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165 | { |
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166 | case MOTOR_ABSOLUTE:/* Speed given as absolute */ |
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167 | return abs_speed;
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168 | case MOTOR_PERCENT:/* Convert from percentage */ |
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169 | return abs_speed * 100 / MAXSPEED; |
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170 | case MOTOR_MMS:/* Convert from mm/s */ |
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171 | /** @todo Make math to do this conversion **/
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172 | return abs_speed;
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173 | case MOTOR_CMS:/* Convert from cm/s */ |
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174 | /** @todo Make math to do this conversion **/
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175 | return abs_speed;
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176 | default: /* The units aren't recognized */ |
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177 | /** @todo Decide on default case. Either percent or absolute. **/
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178 | return abs_speed;
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179 | } |
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180 | } |
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181 | |||
182 | /**
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183 | 18e2028b | Alex | * @brief Motors driver. This is a ROS node that controls motor speeds.
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184 | *
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185 | * This is the main function for the motors node. It is run when the node
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186 | * starts and initializes the motors. It then subscribes to the
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187 | * set_motors, and set_motor_speeds topics, and advertises the
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188 | * query_motors service.
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189 | *
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190 | * @param argc The number of command line arguments (should be 1)
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191 | * @param argv The array of command line arguments
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192 | **/
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193 | int main(int argc, char **argv) |
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194 | { |
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195 | /* Initialize in ROS the motors driver node */
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196 | ros::init(argc, argv, "motors_driver");
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197 | |||
198 | /* Advertise that this serves the query_motors service */
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199 | ros::NodeHandle n; |
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200 | ros::ServiceServer service = n.advertiseService("query_motors",
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201 | motors_query); |
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202 | |||
203 | /* Subscribe to the set_motors topic */
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204 | 14736c0c | Ben Wasserman | ros::Subscriber sub0 = n.subscribe("set_motors", QUEUE_SIZE, motors_set);
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205 | 18e2028b | Alex | |
206 | /* Initialize hardware for motors */
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207 | // Hardware init functions here
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208 | |||
209 | ROS_INFO("Ready to set motors.");
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210 | ros::spin(); |
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211 | c406f16b | Ben | |
212 | 18e2028b | Alex | return 0; |
213 | c406f16b | Ben | } |
214 | |||
215 | 18e2028b | Alex | /** @} **/ |