Cooper Liu / Mbed 2 deprecated ICRSEurobot13

Colour sensors calibrated

Dependencies:   mbed-rtos mbed Servo QEI

Fork of ICRSEurobot13 by Thomas Branch

Processes/Motion/motion.cpp@33:e3f633620816, 2013-04-10 (annotated)

Committer:
madcowswe
Date:
Wed Apr 10 18:25:16 2013 +0000
Revision:
33:e3f633620816
Parent:
27:7cb3a21d9a2e
Parent:
31:791739422122
Child:
34:a49197572737
Merged ryan oskar

Who changed what in which revision?

UserRevisionLine numberNew contents of line
rsavitski 25:50805ef8c499 1 ////////////////////////////////////////////////////////////////////////////////
rsavitski 25:50805ef8c499 2 // Motion control unit
rsavitski 25:50805ef8c499 3 ////////////////////////////////////////////////////////////////////////////////
rsavitski 25:50805ef8c499 4 // Takes current state of the robot and target waypoint,
rsavitski 25:50805ef8c499 5 // calculates desired forward and angular velocities and requests those from the motor control layer.
rsavitski 25:50805ef8c499 6 ////////////////////////////////////////////////////////////////////////////////
rsavitski 25:50805ef8c499 7
rsavitski 25:50805ef8c499 8 #include "motion.h"
rsavitski 25:50805ef8c499 9
rsavitski 25:50805ef8c499 10 namespace motion
rsavitski 25:50805ef8c499 11 {
rsavitski 25:50805ef8c499 12
rsavitski 25:50805ef8c499 13 void motionlayer(void const *dummy)
rsavitski 31:791739422122 14 {
rsavitski 25:50805ef8c499 15 // get target waypoint from AI
rsavitski 25:50805ef8c499 16 Waypoint target_waypoint = *AI::current_waypoint;
rsavitski 25:50805ef8c499 17
rsavitski 25:50805ef8c499 18 // get current state from Kalman
madcowswe 27:7cb3a21d9a2e 19 using Kalman::State;
rsavitski 25:50805ef8c499 20 State current_state = Kalman::getState();
rsavitski 25:50805ef8c499 21
rsavitski 25:50805ef8c499 22 float delta_x = target_waypoint.x - current_state.x;
rsavitski 25:50805ef8c499 23 float delta_y = target_waypoint.y - current_state.y;
rsavitski 25:50805ef8c499 24
madcowswe 26:b16f1045108f 25 //printf("motion sees deltax: %f deltay %f\r\n", delta_x, delta_y);
rsavitski 25:50805ef8c499 26
madcowswe 26:b16f1045108f 27 float distance_err = hypot(delta_x, delta_y);
madcowswe 26:b16f1045108f 28
madcowswe 26:b16f1045108f 29 float angle_err = constrainAngle(atan2(delta_y, delta_x) - current_state.theta);
rsavitski 25:50805ef8c499 30
rsavitski 31:791739422122 31 // is the waypoint reached
rsavitski 31:791739422122 32 if (distance_err < target_waypoint.pos_threshold)
rsavitski 31:791739422122 33 {
rsavitski 31:791739422122 34 distance_err = 0;
rsavitski 31:791739422122 35 }
rsavitski 31:791739422122 36 if (abs(angle_err) < target_waypoint.angle_threshold)
rsavitski 31:791739422122 37 {
rsavitski 31:791739422122 38 angle_err = 0;
rsavitski 31:791739422122 39 }
rsavitski 31:791739422122 40
rsavitski 31:791739422122 41 AI::waypoint_flag_mutex.lock(); // proper way would be to construct a function to evaluate the condition and pass the function pointer to a conditional setter function for reached flag
rsavitski 31:791739422122 42 if (distance_err == 0 && angle_err == 0)
rsavitski 31:791739422122 43 {
rsavitski 31:791739422122 44 AI::setWaypointReached();
rsavitski 31:791739422122 45 return;
rsavitski 31:791739422122 46 }
rsavitski 31:791739422122 47 AI::waypoint_flag_mutex.unlock();
rsavitski 25:50805ef8c499 48
rsavitski 25:50805ef8c499 49 // angular velocity controller
madcowswe 26:b16f1045108f 50 const float p_gain_av = 0.3; //TODO: tune
rsavitski 25:50805ef8c499 51
madcowswe 26:b16f1045108f 52 const float max_av = 0.2*PI; // radians per sec //TODO: tune
rsavitski 25:50805ef8c499 53
rsavitski 25:50805ef8c499 54 // angle error [-pi, pi]
rsavitski 25:50805ef8c499 55 float angular_v = p_gain_av * angle_err;
rsavitski 25:50805ef8c499 56
rsavitski 25:50805ef8c499 57 // constrain range
rsavitski 25:50805ef8c499 58 if (angular_v > max_av)
rsavitski 25:50805ef8c499 59 angular_v = max_av;
rsavitski 25:50805ef8c499 60 else if (angular_v < -max_av)
rsavitski 25:50805ef8c499 61 angular_v = -max_av;
rsavitski 25:50805ef8c499 62
rsavitski 25:50805ef8c499 63
rsavitski 25:50805ef8c499 64 // forward velocity controller
madcowswe 26:b16f1045108f 65 const float p_gain_fv = 0.3; //TODO: tune
rsavitski 25:50805ef8c499 66
madcowswe 26:b16f1045108f 67 float max_fv = 0.2; // meters per sec //TODO: tune
rsavitski 25:50805ef8c499 68 const float angle_envelope_exponent = 8.0; //TODO: tune
rsavitski 25:50805ef8c499 69
rsavitski 25:50805ef8c499 70 // control, distance_err in meters
rsavitski 25:50805ef8c499 71 float forward_v = p_gain_fv * distance_err;
rsavitski 25:50805ef8c499 72
rsavitski 25:50805ef8c499 73 // control the forward velocity envelope based on angular error
rsavitski 25:50805ef8c499 74 max_fv = max_fv * pow(cos(angle_err/2), angle_envelope_exponent);
rsavitski 25:50805ef8c499 75
rsavitski 25:50805ef8c499 76 // constrain range
rsavitski 25:50805ef8c499 77 if (forward_v > max_fv)
rsavitski 25:50805ef8c499 78 forward_v = max_fv;
rsavitski 25:50805ef8c499 79 else if (forward_v < -max_fv)
rsavitski 25:50805ef8c499 80 forward_v = -max_fv;
madcowswe 26:b16f1045108f 81
madcowswe 26:b16f1045108f 82 //printf("fwd: %f, omega: %f\r\n", forward_v, angular_v);
rsavitski 25:50805ef8c499 83
rsavitski 31:791739422122 84 // pass values to the motor control
rsavitski 25:50805ef8c499 85 MotorControl::set_fwdcmd(forward_v);
madcowswe 26:b16f1045108f 86 MotorControl::set_omegacmd(angular_v);
rsavitski 25:50805ef8c499 87 }
rsavitski 25:50805ef8c499 88
rsavitski 25:50805ef8c499 89 } //namespace