Psi Swarm Robot / PsiSwarmV8_CPP

C++ Library for the PsiSwarm Robot - Version 0.8

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motors.cpp@6:b340a527add9, 2016-10-15 (annotated)

Committer:
jah128
Date:
Sat Oct 15 13:51:39 2016 +0000
Revision:
6:b340a527add9
Parent:
5:3cdd1a37cdd7
Child:
8:6c92789d5f87
Added Apache license to files

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jah128 0:d6269d17c8cf 1 /* University of York Robotics Laboratory PsiSwarm Library: Motor Functions Source File
jah128 6:b340a527add9 2 *
jah128 6:b340a527add9 3 * Copyright 2016 University of York
jah128 6:b340a527add9 4 *
jah128 6:b340a527add9 5 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
jah128 6:b340a527add9 6 * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
jah128 6:b340a527add9 7 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS
jah128 6:b340a527add9 8 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
jah128 6:b340a527add9 9 * See the License for the specific language governing permissions and limitations under the License.
jah128 0:d6269d17c8cf 10 *
jah128 0:d6269d17c8cf 11 * File: motors.cpp
jah128 0:d6269d17c8cf 12 *
jah128 0:d6269d17c8cf 13 * (C) Dept. Electronics & Computer Science, University of York
jah128 0:d6269d17c8cf 14 * James Hilder, Alan Millard, Alexander Horsfield, Homero Elizondo, Jon Timmis
jah128 0:d6269d17c8cf 15 *
jah128 5:3cdd1a37cdd7 16 * PsiSwarm Library Version: 0.7
jah128 0:d6269d17c8cf 17 *
jah128 5:3cdd1a37cdd7 18 * October 2016
jah128 0:d6269d17c8cf 19 *
jah128 0:d6269d17c8cf 20 *
jah128 0:d6269d17c8cf 21 */
jah128 0:d6269d17c8cf 22
jah128 0:d6269d17c8cf 23 #include "psiswarm.h"
jah128 0:d6269d17c8cf 24
jah128 0:d6269d17c8cf 25 Timeout time_based_action_timeout;
jah128 0:d6269d17c8cf 26 char brake_when_done = 0;
jah128 0:d6269d17c8cf 27
jah128 0:d6269d17c8cf 28 void set_left_motor_speed(float speed)
jah128 0:d6269d17c8cf 29 {
jah128 0:d6269d17c8cf 30 motor_left_speed = speed;
jah128 0:d6269d17c8cf 31 motor_left_brake = 0;
jah128 0:d6269d17c8cf 32 IF_update_motors();
jah128 0:d6269d17c8cf 33 }
jah128 0:d6269d17c8cf 34
jah128 0:d6269d17c8cf 35 void set_right_motor_speed(float speed)
jah128 0:d6269d17c8cf 36 {
jah128 0:d6269d17c8cf 37 motor_right_speed = speed;
jah128 0:d6269d17c8cf 38 motor_right_brake = 0;
jah128 0:d6269d17c8cf 39 IF_update_motors();
jah128 0:d6269d17c8cf 40 }
jah128 0:d6269d17c8cf 41
jah128 0:d6269d17c8cf 42 void brake_left_motor()
jah128 0:d6269d17c8cf 43 {
jah128 0:d6269d17c8cf 44 motor_left_speed = 0;
jah128 0:d6269d17c8cf 45 motor_left_brake = 1;
jah128 0:d6269d17c8cf 46 IF_update_motors();
jah128 0:d6269d17c8cf 47 }
jah128 0:d6269d17c8cf 48
jah128 0:d6269d17c8cf 49 void brake_right_motor()
jah128 0:d6269d17c8cf 50 {
jah128 0:d6269d17c8cf 51 motor_right_speed = 0;
jah128 0:d6269d17c8cf 52 motor_right_brake = 1;
jah128 0:d6269d17c8cf 53 IF_update_motors();
jah128 0:d6269d17c8cf 54 }
jah128 0:d6269d17c8cf 55
jah128 0:d6269d17c8cf 56 void brake()
jah128 0:d6269d17c8cf 57 {
jah128 0:d6269d17c8cf 58 motor_left_speed = 0;
jah128 0:d6269d17c8cf 59 motor_right_speed = 0;
jah128 0:d6269d17c8cf 60 motor_left_brake = 1;
jah128 0:d6269d17c8cf 61 motor_right_brake = 1;
jah128 0:d6269d17c8cf 62 IF_update_motors();
jah128 0:d6269d17c8cf 63 }
jah128 0:d6269d17c8cf 64
jah128 0:d6269d17c8cf 65 void stop()
jah128 0:d6269d17c8cf 66 {
jah128 0:d6269d17c8cf 67 motor_left_speed = 0;
jah128 0:d6269d17c8cf 68 motor_right_speed = 0;
jah128 0:d6269d17c8cf 69 motor_left_brake = 0;
jah128 0:d6269d17c8cf 70 motor_right_brake = 0;
jah128 0:d6269d17c8cf 71 IF_update_motors();
jah128 0:d6269d17c8cf 72 }
jah128 0:d6269d17c8cf 73
jah128 0:d6269d17c8cf 74 void forward(float speed)
jah128 0:d6269d17c8cf 75 {
jah128 0:d6269d17c8cf 76 motor_left_speed = speed;
jah128 0:d6269d17c8cf 77 motor_right_speed = speed;
jah128 0:d6269d17c8cf 78 motor_left_brake = 0;
jah128 0:d6269d17c8cf 79 motor_right_brake = 0;
jah128 0:d6269d17c8cf 80 IF_update_motors();
jah128 0:d6269d17c8cf 81 }
jah128 0:d6269d17c8cf 82
jah128 0:d6269d17c8cf 83 void backward(float speed)
jah128 0:d6269d17c8cf 84 {
jah128 0:d6269d17c8cf 85 motor_left_speed = -speed;
jah128 0:d6269d17c8cf 86 motor_right_speed = -speed;
jah128 0:d6269d17c8cf 87 motor_left_brake = 0;
jah128 0:d6269d17c8cf 88 motor_right_brake = 0;
jah128 0:d6269d17c8cf 89 IF_update_motors();
jah128 0:d6269d17c8cf 90 }
jah128 0:d6269d17c8cf 91
jah128 0:d6269d17c8cf 92 void turn(float speed)
jah128 0:d6269d17c8cf 93 {
jah128 0:d6269d17c8cf 94 //A positive turn is clockwise
jah128 0:d6269d17c8cf 95 motor_left_speed = speed;
jah128 0:d6269d17c8cf 96 motor_right_speed = -speed;
jah128 0:d6269d17c8cf 97 motor_left_brake = 0;
jah128 0:d6269d17c8cf 98 motor_right_brake = 0;
jah128 0:d6269d17c8cf 99 IF_update_motors();
jah128 0:d6269d17c8cf 100 }
jah128 0:d6269d17c8cf 101
jah128 0:d6269d17c8cf 102 //Forward for a set period of time
jah128 0:d6269d17c8cf 103 void time_based_forward(float speed, int microseconds, char brake)
jah128 0:d6269d17c8cf 104 {
jah128 0:d6269d17c8cf 105 //Check if a current time based action is running - if it is, throw a warning and cancel its timeout
jah128 0:d6269d17c8cf 106 IF_check_time_for_existing_time_based_action();
jah128 0:d6269d17c8cf 107
jah128 0:d6269d17c8cf 108 //Start moving
jah128 0:d6269d17c8cf 109 forward(speed);
jah128 0:d6269d17c8cf 110 brake_when_done = brake;
jah128 0:d6269d17c8cf 111 time_based_action_timeout.attach_us(&IF_end_time_based_action,microseconds);
jah128 0:d6269d17c8cf 112 }
jah128 0:d6269d17c8cf 113
jah128 0:d6269d17c8cf 114 //Turn for a set period of time
jah128 0:d6269d17c8cf 115 void time_based_turn(float speed, int microseconds, char brake)
jah128 0:d6269d17c8cf 116 {
jah128 0:d6269d17c8cf 117 //Check if a current time based action is running - if it is, throw a warning and cancel its timeout
jah128 0:d6269d17c8cf 118 IF_check_time_for_existing_time_based_action();
jah128 0:d6269d17c8cf 119
jah128 0:d6269d17c8cf 120 //Start turning
jah128 0:d6269d17c8cf 121 turn(speed);
jah128 0:d6269d17c8cf 122 brake_when_done = brake;
jah128 0:d6269d17c8cf 123 time_based_action_timeout.attach_us(&IF_end_time_based_action,microseconds);
jah128 0:d6269d17c8cf 124 }
jah128 0:d6269d17c8cf 125
jah128 0:d6269d17c8cf 126 //Returns the limit of degrees available to turn in given time
jah128 0:d6269d17c8cf 127 float get_maximum_turn_angle(int microseconds){
jah128 0:d6269d17c8cf 128 //We can turn at about 270 degrees per second at full speed
jah128 0:d6269d17c8cf 129 return (microseconds * 0.00027);
jah128 0:d6269d17c8cf 130 }
jah128 0:d6269d17c8cf 131
jah128 0:d6269d17c8cf 132 //Return the time in microseconds that performing the turn will take
jah128 0:d6269d17c8cf 133 int get_time_based_turn_time(float speed, float degrees)
jah128 0:d6269d17c8cf 134 {
jah128 0:d6269d17c8cf 135 //Check sign of degrees
jah128 0:d6269d17c8cf 136 if(degrees < 0) degrees =- degrees;
jah128 0:d6269d17c8cf 137
jah128 0:d6269d17c8cf 138 //Main calculation for turn time
jah128 0:d6269d17c8cf 139 float turn_time = degrees / ((290 * speed));
jah128 0:d6269d17c8cf 140
jah128 0:d6269d17c8cf 141 //Add a hard offset of 4ms to account for start\stop time
jah128 0:d6269d17c8cf 142 if(degrees > 4) {
jah128 0:d6269d17c8cf 143 turn_time += 0.004;
jah128 0:d6269d17c8cf 144 } else turn_time += 0.002;
jah128 0:d6269d17c8cf 145
jah128 0:d6269d17c8cf 146 // Add offset for slow speed
jah128 0:d6269d17c8cf 147 if(speed<0.31) {
jah128 0:d6269d17c8cf 148 float mul_fact = 0.31 - speed;
jah128 0:d6269d17c8cf 149 if(mul_fact < 0) mul_fact = 0;
jah128 0:d6269d17c8cf 150 mul_fact /= 2;
jah128 0:d6269d17c8cf 151 mul_fact += 1;
jah128 0:d6269d17c8cf 152 turn_time *= mul_fact;
jah128 0:d6269d17c8cf 153 }
jah128 0:d6269d17c8cf 154
jah128 0:d6269d17c8cf 155 // Add offset for short turns
jah128 0:d6269d17c8cf 156 if(degrees < 360) {
jah128 0:d6269d17c8cf 157 float short_offset_multiplier = 1.0 + (0.9 / degrees);
jah128 0:d6269d17c8cf 158 turn_time *= short_offset_multiplier;
jah128 0:d6269d17c8cf 159 }
jah128 0:d6269d17c8cf 160
jah128 0:d6269d17c8cf 161 // Convert to uS
jah128 0:d6269d17c8cf 162 turn_time *= 1000000;
jah128 0:d6269d17c8cf 163
jah128 0:d6269d17c8cf 164 return (int) turn_time;
jah128 0:d6269d17c8cf 165 }
jah128 0:d6269d17c8cf 166
jah128 0:d6269d17c8cf 167 //Turn the robot a set number of degrees [using time estimation to end turn]
jah128 0:d6269d17c8cf 168 int time_based_turn_degrees(float speed, float degrees, char brake)
jah128 0:d6269d17c8cf 169 {
jah128 0:d6269d17c8cf 170 if(speed < 0 || speed > 1 || degrees == 0) {
jah128 0:d6269d17c8cf 171 debug("Invalid values to time based turn: speed=%f degrees=$f\n",speed,degrees);
jah128 0:d6269d17c8cf 172 return 0;
jah128 0:d6269d17c8cf 173 } else {
jah128 0:d6269d17c8cf 174 //Check if a current time based action is running - if it is, throw a warning and cancel its timeout
jah128 0:d6269d17c8cf 175 IF_check_time_for_existing_time_based_action();
jah128 0:d6269d17c8cf 176
jah128 0:d6269d17c8cf 177 //Calculate turn time using get_time_based_turn_time
jah128 0:d6269d17c8cf 178 int turn_time = get_time_based_turn_time(speed,degrees);
jah128 0:d6269d17c8cf 179
jah128 0:d6269d17c8cf 180 //Set correct turn direction (-degrees is a counter-clockwise turn)
jah128 0:d6269d17c8cf 181 if(degrees < 0) {
jah128 0:d6269d17c8cf 182 degrees=-degrees;
jah128 0:d6269d17c8cf 183 speed=-speed;
jah128 0:d6269d17c8cf 184 }
jah128 0:d6269d17c8cf 185
jah128 0:d6269d17c8cf 186 //Start turning
jah128 0:d6269d17c8cf 187 turn(speed);
jah128 0:d6269d17c8cf 188
jah128 0:d6269d17c8cf 189 brake_when_done = brake;
jah128 0:d6269d17c8cf 190 time_based_action_timeout.attach_us(&IF_end_time_based_action,turn_time);
jah128 0:d6269d17c8cf 191 return turn_time;
jah128 0:d6269d17c8cf 192 }
jah128 0:d6269d17c8cf 193 }
jah128 0:d6269d17c8cf 194
jah128 0:d6269d17c8cf 195 //Check if a current time based action is running - if it is, throw a warning and cancel its timeout
jah128 0:d6269d17c8cf 196 void IF_check_time_for_existing_time_based_action()
jah128 0:d6269d17c8cf 197 {
jah128 0:d6269d17c8cf 198 if(time_based_motor_action == 1){
jah128 0:d6269d17c8cf 199 time_based_action_timeout.detach();
jah128 0:d6269d17c8cf 200 debug("WARNING: New time-based action called before previous action finished!\n");
jah128 0:d6269d17c8cf 201 }
jah128 0:d6269d17c8cf 202 else time_based_motor_action = 1;
jah128 0:d6269d17c8cf 203 }
jah128 0:d6269d17c8cf 204
jah128 0:d6269d17c8cf 205 void IF_end_time_based_action()
jah128 0:d6269d17c8cf 206 {
jah128 0:d6269d17c8cf 207 if(brake_when_done == 1)brake();
jah128 0:d6269d17c8cf 208 else stop();
jah128 0:d6269d17c8cf 209 time_based_motor_action = 0;
jah128 0:d6269d17c8cf 210 }
jah128 0:d6269d17c8cf 211
jah128 0:d6269d17c8cf 212 void IF_update_motors()
jah128 0:d6269d17c8cf 213 {
jah128 0:d6269d17c8cf 214 if(motor_left_speed > 1.0) {
jah128 0:d6269d17c8cf 215 motor_left_speed = 1.0;
jah128 0:d6269d17c8cf 216 //Throw exception...
jah128 0:d6269d17c8cf 217 }
jah128 0:d6269d17c8cf 218 if(motor_right_speed > 1.0) {
jah128 0:d6269d17c8cf 219 motor_right_speed = 1.0;
jah128 0:d6269d17c8cf 220 //Throw exception...
jah128 0:d6269d17c8cf 221 }
jah128 0:d6269d17c8cf 222 if(motor_left_speed < -1.0) {
jah128 0:d6269d17c8cf 223 motor_left_speed = -1.0;
jah128 0:d6269d17c8cf 224 //Throw exception...
jah128 0:d6269d17c8cf 225 }
jah128 0:d6269d17c8cf 226 if(motor_right_speed < -1.0) {
jah128 0:d6269d17c8cf 227 motor_right_speed = -1.0;
jah128 0:d6269d17c8cf 228 //Throw exception...
jah128 0:d6269d17c8cf 229 }
jah128 0:d6269d17c8cf 230 if(motor_left_brake) {
jah128 0:d6269d17c8cf 231 motor_left_f.write(1);
jah128 0:d6269d17c8cf 232 motor_left_r.write(1);
jah128 0:d6269d17c8cf 233 if(motor_left_speed!=0) {
jah128 0:d6269d17c8cf 234 motor_left_speed = 0;
jah128 0:d6269d17c8cf 235 //Throw exception...
jah128 0:d6269d17c8cf 236 }
jah128 0:d6269d17c8cf 237 } else {
jah128 0:d6269d17c8cf 238 if(motor_left_speed >= 0) {
jah128 0:d6269d17c8cf 239 motor_left_f.write(0);
jah128 4:1c621cb8cf0d 240 motor_left_r.write(IF_calibrated_left_speed(motor_left_speed));
jah128 0:d6269d17c8cf 241
jah128 0:d6269d17c8cf 242 } else {
jah128 0:d6269d17c8cf 243 motor_left_r.write(0);
jah128 4:1c621cb8cf0d 244 motor_left_f.write(IF_calibrated_left_speed(-motor_left_speed));
jah128 0:d6269d17c8cf 245 }
jah128 0:d6269d17c8cf 246 }
jah128 0:d6269d17c8cf 247 if(motor_right_brake) {
jah128 0:d6269d17c8cf 248 motor_right_f.write(1);
jah128 0:d6269d17c8cf 249 motor_right_r.write(1);
jah128 0:d6269d17c8cf 250 if(motor_right_speed!=0) {
jah128 0:d6269d17c8cf 251 motor_right_speed = 0;
jah128 0:d6269d17c8cf 252 //Throw exception...
jah128 0:d6269d17c8cf 253 }
jah128 0:d6269d17c8cf 254 } else {
jah128 0:d6269d17c8cf 255 if(motor_right_speed >= 0) {
jah128 0:d6269d17c8cf 256 motor_right_f.write(0);
jah128 4:1c621cb8cf0d 257 motor_right_r.write(IF_calibrated_right_speed(motor_right_speed));
jah128 0:d6269d17c8cf 258 } else {
jah128 0:d6269d17c8cf 259 motor_right_r.write(0);
jah128 4:1c621cb8cf0d 260 motor_right_f.write(IF_calibrated_right_speed(-motor_right_speed));
jah128 0:d6269d17c8cf 261 }
jah128 0:d6269d17c8cf 262 }
jah128 0:d6269d17c8cf 263
jah128 0:d6269d17c8cf 264 }
jah128 0:d6269d17c8cf 265
jah128 0:d6269d17c8cf 266
jah128 4:1c621cb8cf0d 267 float IF_calibrated_left_speed(float speed)
jah128 4:1c621cb8cf0d 268 {
jah128 4:1c621cb8cf0d 269 //Takes the input value, adds an offset if OFFSET_MOTORS enabled and weights the value if USE_MOTOR_CALIBRATION enabled
jah128 4:1c621cb8cf0d 270 float adjusted = IF_calibrated_speed(speed);
jah128 4:1c621cb8cf0d 271 if(use_motor_calibration){
jah128 4:1c621cb8cf0d 272 adjusted *= left_motor_calibration_value;
jah128 4:1c621cb8cf0d 273 }
jah128 4:1c621cb8cf0d 274 return adjusted;
jah128 4:1c621cb8cf0d 275 }
jah128 4:1c621cb8cf0d 276
jah128 4:1c621cb8cf0d 277 float IF_calibrated_right_speed(float speed)
jah128 4:1c621cb8cf0d 278 {
jah128 4:1c621cb8cf0d 279 //Takes the input value, adds an offset if OFFSET_MOTORS enabled and weights the value if USE_MOTOR_CALIBRATION enabled
jah128 4:1c621cb8cf0d 280 float adjusted = IF_calibrated_speed(speed);
jah128 4:1c621cb8cf0d 281 if(use_motor_calibration){
jah128 4:1c621cb8cf0d 282 adjusted *= right_motor_calibration_value;
jah128 4:1c621cb8cf0d 283 }
jah128 4:1c621cb8cf0d 284 return adjusted;
jah128 4:1c621cb8cf0d 285 }
jah128 4:1c621cb8cf0d 286
jah128 0:d6269d17c8cf 287 float IF_calibrated_speed(float speed)
jah128 0:d6269d17c8cf 288 {
jah128 0:d6269d17c8cf 289 if(speed == 0) return 0;
jah128 0:d6269d17c8cf 290 //Converts an input value to take account of the stall speed of the motor; aims to produce a more linear speed
jah128 0:d6269d17c8cf 291 float adjusted = speed;
jah128 0:d6269d17c8cf 292 if(OFFSET_MOTORS) {
jah128 0:d6269d17c8cf 293 adjusted*=0.8f;
jah128 0:d6269d17c8cf 294 adjusted+=0.2;
jah128 0:d6269d17c8cf 295 }
jah128 0:d6269d17c8cf 296 return adjusted;
jah128 0:d6269d17c8cf 297 }
jah128 0:d6269d17c8cf 298
jah128 0:d6269d17c8cf 299 void IF_init_motors()
jah128 0:d6269d17c8cf 300 {
jah128 0:d6269d17c8cf 301 // Motor PWM outputs work optimally at 25kHz frequency
jah128 0:d6269d17c8cf 302 motor_left_f.period_us(40);
jah128 0:d6269d17c8cf 303 motor_right_f.period_us(40);
jah128 0:d6269d17c8cf 304 motor_left_r.period_us(40);
jah128 0:d6269d17c8cf 305 motor_right_r.period_us(40);
jah128 0:d6269d17c8cf 306 motor_left_speed = 0;
jah128 0:d6269d17c8cf 307 motor_right_speed = 0;
jah128 0:d6269d17c8cf 308 motor_left_brake = 0;
jah128 0:d6269d17c8cf 309 motor_right_brake = 0;
jah128 0:d6269d17c8cf 310 IF_update_motors();
jah128 0:d6269d17c8cf 311 }