Sridevi Kaza / Mbed OS project

nov 18th

Dependencies:   Bezier_Traj_Follower_Example ExperimentServer QEI_pmw MotorShield

main.cpp@17:1bb5aa45826e, 2020-09-25 (annotated)

Committer:
saloutos
Date:
Fri Sep 25 04:39:17 2020 +0000
Revision:
17:1bb5aa45826e
Parent:
16:f9ea2b2d410f
Child:
18:21c8d94eddee
Fixed bugs and added inverse kinematics for joint space

Who changed what in which revision?

UserRevisionLine numberNew contents of line
pwensing 0:43448bf056e8 1 #include "mbed.h"
pwensing 0:43448bf056e8 2 #include "rtos.h"
pwensing 0:43448bf056e8 3 #include "EthernetInterface.h"
pwensing 0:43448bf056e8 4 #include "ExperimentServer.h"
pwensing 0:43448bf056e8 5 #include "QEI.h"
saloutos 16:f9ea2b2d410f 6 #include "BezierCurve.h"
elijahsj 6:1faceb53dabe 7 #include "MotorShield.h"
elijahsj 13:3a1f4e09789b 8 #include "HardwareSetup.h"
pwensing 0:43448bf056e8 9
saloutos 16:f9ea2b2d410f 10 #define BEZIER_ORDER_FOOT 7
saloutos 17:1bb5aa45826e 11 #define NUM_INPUTS (12 + 2*(BEZIER_ORDER_FOOT+1))
saloutos 16:f9ea2b2d410f 12 #define NUM_OUTPUTS 19
pwensing 0:43448bf056e8 13
saloutos 16:f9ea2b2d410f 14 #define PULSE_TO_RAD (2.0f*3.14159f / 1200.0f)
saloutos 16:f9ea2b2d410f 15
saloutos 16:f9ea2b2d410f 16 // Initializations
pwensing 0:43448bf056e8 17 Serial pc(USBTX, USBRX); // USB Serial Terminal
pwensing 0:43448bf056e8 18 ExperimentServer server; // Object that lets us communicate with MATLAB
elijahsj 5:1ab9b2527794 19 Timer t; // Timer to measure elapsed time of experiment
elijahsj 5:1ab9b2527794 20
elijahsj 5:1ab9b2527794 21 QEI encoderA(PE_9,PE_11, NC, 1200, QEI::X4_ENCODING); // MOTOR A ENCODER (no index, 1200 counts/rev, Quadrature encoding)
elijahsj 5:1ab9b2527794 22 QEI encoderB(PA_5, PB_3, NC, 1200, QEI::X4_ENCODING); // MOTOR B ENCODER (no index, 1200 counts/rev, Quadrature encoding)
elijahsj 5:1ab9b2527794 23 QEI encoderC(PC_6, PC_7, NC, 1200, QEI::X4_ENCODING); // MOTOR C ENCODER (no index, 1200 counts/rev, Quadrature encoding)
elijahsj 5:1ab9b2527794 24 QEI encoderD(PD_12, PD_13, NC, 1200, QEI::X4_ENCODING);// MOTOR D ENCODER (no index, 1200 counts/rev, Quadrature encoding)
elijahsj 5:1ab9b2527794 25
elijahsj 12:84a6dcb60422 26 MotorShield motorShield(12000); //initialize the motor shield with a period of 12000 ticks or ~20kHZ
saloutos 16:f9ea2b2d410f 27 Ticker currentLoop;
saloutos 16:f9ea2b2d410f 28
saloutos 16:f9ea2b2d410f 29 // Variables for q1
saloutos 16:f9ea2b2d410f 30 float current1;
saloutos 16:f9ea2b2d410f 31 float current_des1 = 0;
saloutos 16:f9ea2b2d410f 32 float prev_current_des1 = 0;
saloutos 16:f9ea2b2d410f 33 float current_int1 = 0;
saloutos 16:f9ea2b2d410f 34 float angle1;
saloutos 16:f9ea2b2d410f 35 float angle_des1;
saloutos 16:f9ea2b2d410f 36 float velocity1;
saloutos 16:f9ea2b2d410f 37 float velocity_des1;
saloutos 16:f9ea2b2d410f 38 float duty_cycle1;
saloutos 16:f9ea2b2d410f 39 float angle1_init;
saloutos 16:f9ea2b2d410f 40
saloutos 16:f9ea2b2d410f 41 // Variables for q2
saloutos 16:f9ea2b2d410f 42 float current2;
saloutos 16:f9ea2b2d410f 43 float current_des2 = 0;
saloutos 16:f9ea2b2d410f 44 float prev_current_des2 = 0;
saloutos 16:f9ea2b2d410f 45 float current_int2 = 0;
saloutos 16:f9ea2b2d410f 46 float angle2;
saloutos 16:f9ea2b2d410f 47 float angle_des2;
saloutos 16:f9ea2b2d410f 48 float velocity2;
saloutos 16:f9ea2b2d410f 49 float velocity_des2;
saloutos 16:f9ea2b2d410f 50 float duty_cycle2;
saloutos 16:f9ea2b2d410f 51 float angle2_init;
saloutos 16:f9ea2b2d410f 52
saloutos 16:f9ea2b2d410f 53 // Fixed kinematic parameters
saloutos 16:f9ea2b2d410f 54 const float l_OA=.011;
saloutos 16:f9ea2b2d410f 55 const float l_OB=.042;
saloutos 16:f9ea2b2d410f 56 const float l_AC=.096;
saloutos 16:f9ea2b2d410f 57 const float l_DE=.091;
saloutos 16:f9ea2b2d410f 58
saloutos 16:f9ea2b2d410f 59 // Timing parameters
saloutos 16:f9ea2b2d410f 60 float current_control_period_us = 200.0f; // 5kHz current control loop
saloutos 16:f9ea2b2d410f 61 float impedance_control_period_us = 1000.0f; // 1kHz impedance control loop
saloutos 16:f9ea2b2d410f 62 float start_period, traj_period, end_period;
saloutos 16:f9ea2b2d410f 63
saloutos 16:f9ea2b2d410f 64 // Control parameters
saloutos 16:f9ea2b2d410f 65 float current_Kp = 0.7;
saloutos 16:f9ea2b2d410f 66 float current_Ki = 0.2;
saloutos 16:f9ea2b2d410f 67 float current_int_max = 1.0;
saloutos 16:f9ea2b2d410f 68 float duty_max;
saloutos 16:f9ea2b2d410f 69 float K_xx;
saloutos 16:f9ea2b2d410f 70 float K_yy;
saloutos 16:f9ea2b2d410f 71 float K_xy;
saloutos 16:f9ea2b2d410f 72 float D_xx;
saloutos 16:f9ea2b2d410f 73 float D_xy;
saloutos 16:f9ea2b2d410f 74 float D_yy;
saloutos 16:f9ea2b2d410f 75
saloutos 16:f9ea2b2d410f 76 // Model parameters
saloutos 17:1bb5aa45826e 77 float supply_voltage = 12; // motor supply voltage
saloutos 17:1bb5aa45826e 78 float R = 2.5f; // motor resistance
saloutos 17:1bb5aa45826e 79 float k_t = 0.17f; // motor torque constant
saloutos 17:1bb5aa45826e 80 float nu = 0.0005; // motor viscous friction
saloutos 16:f9ea2b2d410f 81
saloutos 16:f9ea2b2d410f 82 // Current control interrupt function
saloutos 16:f9ea2b2d410f 83 void CurrentLoop()
saloutos 16:f9ea2b2d410f 84 {
saloutos 16:f9ea2b2d410f 85 // This loop sets the motor voltage commands using PI current controllers.
saloutos 16:f9ea2b2d410f 86
saloutos 16:f9ea2b2d410f 87 //use the motor shield as follows:
saloutos 16:f9ea2b2d410f 88 //motorShield.motorAWrite(DUTY CYCLE, DIRECTION), DIRECTION = 0 is forward, DIRECTION =1 is backwards.
saloutos 16:f9ea2b2d410f 89
saloutos 16:f9ea2b2d410f 90 current1 = -(((float(motorShield.readCurrentA())/65536.0f)*30.0f)-15.0f); // measure current
saloutos 16:f9ea2b2d410f 91 float err_c1 = current_des1 - current1; // current errror
saloutos 16:f9ea2b2d410f 92 current_int1 += err_c1; // integrate error
saloutos 16:f9ea2b2d410f 93 current_int1 = fmaxf( fminf(current_int1, current_int_max), -current_int_max); // anti-windup
saloutos 16:f9ea2b2d410f 94 duty_cycle1 = current_Kp*err_c1 + current_Ki*current_int1; // PI current controller
saloutos 16:f9ea2b2d410f 95
saloutos 16:f9ea2b2d410f 96 float absDuty1 = abs(duty_cycle1);
saloutos 16:f9ea2b2d410f 97 if (absDuty1 > duty_max) {
saloutos 16:f9ea2b2d410f 98 duty_cycle1 *= duty_max / absDuty1;
saloutos 16:f9ea2b2d410f 99 absDuty1 = duty_max;
saloutos 16:f9ea2b2d410f 100 }
saloutos 16:f9ea2b2d410f 101 if (duty_cycle1 < 0) { // backwards
saloutos 16:f9ea2b2d410f 102 motorShield.motorAWrite(absDuty1, 1);
saloutos 16:f9ea2b2d410f 103 } else { // forwards
saloutos 16:f9ea2b2d410f 104 motorShield.motorAWrite(absDuty1, 0);
saloutos 16:f9ea2b2d410f 105 }
saloutos 16:f9ea2b2d410f 106 prev_current_des1 = current_des1;
saloutos 16:f9ea2b2d410f 107
saloutos 16:f9ea2b2d410f 108 current2 = -(((float(motorShield.readCurrentB())/65536.0f)*30.0f)-15.0f); // measure current
saloutos 16:f9ea2b2d410f 109 float err_c2 = current_des2 - current2; // current error
saloutos 16:f9ea2b2d410f 110 current_int2 += err_c2; // integrate error
saloutos 16:f9ea2b2d410f 111 current_int2 = fmaxf( fminf(current_int2, current_int_max), -current_int_max); // anti-windup
saloutos 16:f9ea2b2d410f 112 duty_cycle2 = current_Kp*err_c2 + current_Ki*current_int2; // PI current controller
saloutos 16:f9ea2b2d410f 113
saloutos 16:f9ea2b2d410f 114 float absDuty2 = abs(duty_cycle2);
saloutos 16:f9ea2b2d410f 115 if (absDuty2 > duty_max) {
saloutos 16:f9ea2b2d410f 116 duty_cycle2 *= duty_max / absDuty2;
saloutos 16:f9ea2b2d410f 117 absDuty2 = duty_max;
saloutos 16:f9ea2b2d410f 118 }
saloutos 16:f9ea2b2d410f 119 if (duty_cycle2 < 0) { // backwards
saloutos 16:f9ea2b2d410f 120 motorShield.motorBWrite(absDuty2, 1);
saloutos 16:f9ea2b2d410f 121 } else { // forwards
saloutos 16:f9ea2b2d410f 122 motorShield.motorBWrite(absDuty2, 0);
saloutos 16:f9ea2b2d410f 123 }
saloutos 16:f9ea2b2d410f 124 prev_current_des2 = current_des2;
saloutos 16:f9ea2b2d410f 125
saloutos 16:f9ea2b2d410f 126 }
elijahsj 6:1faceb53dabe 127
elijahsj 4:7a1b35f081bb 128 int main (void)
elijahsj 4:7a1b35f081bb 129 {
saloutos 17:1bb5aa45826e 130
saloutos 17:1bb5aa45826e 131 // Object for 7th order Cartesian foot trajectory
saloutos 17:1bb5aa45826e 132 BezierCurve rDesFoot_bez(2,BEZIER_ORDER_FOOT);
saloutos 17:1bb5aa45826e 133
pwensing 0:43448bf056e8 134 // Link the terminal with our server and start it up
pwensing 0:43448bf056e8 135 server.attachTerminal(pc);
pwensing 0:43448bf056e8 136 server.init();
elijahsj 13:3a1f4e09789b 137
pwensing 0:43448bf056e8 138 // Continually get input from MATLAB and run experiments
pwensing 0:43448bf056e8 139 float input_params[NUM_INPUTS];
elijahsj 5:1ab9b2527794 140 pc.printf("%f",input_params[0]);
elijahsj 5:1ab9b2527794 141
pwensing 0:43448bf056e8 142 while(1) {
saloutos 16:f9ea2b2d410f 143
saloutos 16:f9ea2b2d410f 144 // If there are new inputs, this code will run
pwensing 0:43448bf056e8 145 if (server.getParams(input_params,NUM_INPUTS)) {
saloutos 16:f9ea2b2d410f 146
saloutos 16:f9ea2b2d410f 147
saloutos 17:1bb5aa45826e 148 // Get inputs from MATLAB
saloutos 16:f9ea2b2d410f 149 start_period = input_params[0]; // First buffer time, before trajectory
saloutos 16:f9ea2b2d410f 150 traj_period = input_params[1]; // Trajectory time/length
saloutos 16:f9ea2b2d410f 151 end_period = input_params[2]; // Second buffer time, after trajectory
saloutos 16:f9ea2b2d410f 152
saloutos 16:f9ea2b2d410f 153 angle1_init = input_params[3]; // Initial angle for q1 (rad)
saloutos 16:f9ea2b2d410f 154 angle2_init = input_params[4]; // Initial angle for q2 (rad)
elijahsj 4:7a1b35f081bb 155
saloutos 16:f9ea2b2d410f 156 K_xx = input_params[5]; // Foot stiffness N/m
saloutos 16:f9ea2b2d410f 157 K_yy = input_params[6]; // Foot stiffness N/m
saloutos 16:f9ea2b2d410f 158 K_xy = input_params[7]; // Foot stiffness N/m
saloutos 16:f9ea2b2d410f 159 D_xx = input_params[8]; // Foot damping N/(m/s)
saloutos 17:1bb5aa45826e 160 D_yy = input_params[9]; // Foot damping N/(m/s)
saloutos 16:f9ea2b2d410f 161 D_xy = input_params[10]; // Foot damping N/(m/s)
saloutos 16:f9ea2b2d410f 162 duty_max = input_params[11]; // Maximum duty factor
saloutos 16:f9ea2b2d410f 163
saloutos 16:f9ea2b2d410f 164 // TODO: check that this gets inputs correctly?
saloutos 16:f9ea2b2d410f 165 float foot_pts[2*(BEZIER_ORDER_FOOT+1)];
saloutos 16:f9ea2b2d410f 166 for(int i = 0; i<2*(BEZIER_ORDER_FOOT+1);i++) {
saloutos 17:1bb5aa45826e 167 foot_pts[i] = input_params[12+i];
saloutos 16:f9ea2b2d410f 168 }
saloutos 16:f9ea2b2d410f 169 rDesFoot_bez.setPoints(foot_pts);
saloutos 16:f9ea2b2d410f 170
saloutos 16:f9ea2b2d410f 171 // Attach current loop interrupt
saloutos 16:f9ea2b2d410f 172 currentLoop.attach_us(CurrentLoop,current_control_period_us);
saloutos 16:f9ea2b2d410f 173
pwensing 0:43448bf056e8 174 // Setup experiment
pwensing 0:43448bf056e8 175 t.reset();
pwensing 0:43448bf056e8 176 t.start();
elijahsj 5:1ab9b2527794 177 encoderA.reset();
elijahsj 5:1ab9b2527794 178 encoderB.reset();
elijahsj 5:1ab9b2527794 179 encoderC.reset();
elijahsj 5:1ab9b2527794 180 encoderD.reset();
elijahsj 10:a40d180c305c 181
elijahsj 15:495333b2ccf1 182 motorShield.motorAWrite(0, 0); //turn motor A off
saloutos 16:f9ea2b2d410f 183 motorShield.motorBWrite(0, 0); //turn motor B off
saloutos 16:f9ea2b2d410f 184
pwensing 0:43448bf056e8 185 // Run experiment
saloutos 16:f9ea2b2d410f 186 while( t.read() < start_period + traj_period + end_period) {
saloutos 16:f9ea2b2d410f 187
saloutos 17:1bb5aa45826e 188 // Read encoders to get motor states, multiply by negative to match defined generalized coordinates
saloutos 16:f9ea2b2d410f 189 angle1 = encoderA.getPulses() *PULSE_TO_RAD + angle1_init;
saloutos 16:f9ea2b2d410f 190 velocity1 = encoderA.getVelocity() * PULSE_TO_RAD;
saloutos 16:f9ea2b2d410f 191
saloutos 16:f9ea2b2d410f 192 angle2 = encoderB.getPulses() * PULSE_TO_RAD + angle2_init;
saloutos 16:f9ea2b2d410f 193 velocity2 = encoderB.getVelocity() * PULSE_TO_RAD;
saloutos 16:f9ea2b2d410f 194
saloutos 16:f9ea2b2d410f 195 const float th1 = angle1;
saloutos 16:f9ea2b2d410f 196 const float th2 = angle2;
saloutos 16:f9ea2b2d410f 197 const float dth1= velocity1;
saloutos 16:f9ea2b2d410f 198 const float dth2= velocity2;
saloutos 16:f9ea2b2d410f 199
saloutos 16:f9ea2b2d410f 200 // ADD YOUR CONTROL CODE HERE (CALCULATE AND SET DESIRED CURRENTS)
saloutos 16:f9ea2b2d410f 201
saloutos 16:f9ea2b2d410f 202 // Calculate the Jacobian
saloutos 17:1bb5aa45826e 203 // float Jx_th1 = 0;
saloutos 17:1bb5aa45826e 204 // float Jx_th2 = 0;
saloutos 17:1bb5aa45826e 205 // float Jy_th1 = 0;
saloutos 17:1bb5aa45826e 206 // float Jy_th2 = 0;
saloutos 17:1bb5aa45826e 207
saloutos 17:1bb5aa45826e 208 float Jx_th1 = l_AC*cos(th1 + th2) + l_DE*cos(th1) + l_OB*cos(th1);
saloutos 17:1bb5aa45826e 209 float Jx_th2 = l_AC*cos(th1 + th2);
saloutos 17:1bb5aa45826e 210 float Jy_th1 = l_AC*sin(th1 + th2) + l_DE*sin(th1) + l_OB*sin(th1);
saloutos 17:1bb5aa45826e 211 float Jy_th2 = l_AC*sin(th1 + th2);
saloutos 16:f9ea2b2d410f 212
saloutos 17:1bb5aa45826e 213 // Calculate the forward kinematics (position and velocity)
saloutos 17:1bb5aa45826e 214 // float xFoot = 0;
saloutos 17:1bb5aa45826e 215 // float yFoot = 0;
saloutos 17:1bb5aa45826e 216 // float dxFoot = 0;
saloutos 17:1bb5aa45826e 217 // float dyFoot = 0;
saloutos 17:1bb5aa45826e 218
saloutos 17:1bb5aa45826e 219 float xFoot = l_AC*sin(th1 + th2) + l_DE*sin(th1) + l_OB*sin(th1);
saloutos 17:1bb5aa45826e 220 float yFoot = - l_AC*cos(th1 + th2) - l_DE*cos(th1) - l_OB*cos(th1);
saloutos 17:1bb5aa45826e 221 float dxFoot = Jx_th1 * dth1 + Jx_th2 * dth2;
saloutos 17:1bb5aa45826e 222 float dyFoot = Jy_th1 * dth1 + Jy_th2 * dth2;
saloutos 16:f9ea2b2d410f 223
saloutos 16:f9ea2b2d410f 224 // Set gains based on buffer and traj times, then calculate desired x,y from Bezier trajectory at current time if necessary
saloutos 16:f9ea2b2d410f 225 float teff = 0;
saloutos 16:f9ea2b2d410f 226 float vMult = 0;
saloutos 16:f9ea2b2d410f 227 if( t < start_period) {
saloutos 16:f9ea2b2d410f 228 if (K_xx > 0 || K_yy > 0) {
saloutos 17:1bb5aa45826e 229 K_xx = 50;
saloutos 17:1bb5aa45826e 230 K_yy = 50;
saloutos 16:f9ea2b2d410f 231 D_xx = 2;
saloutos 16:f9ea2b2d410f 232 D_yy = 2;
saloutos 16:f9ea2b2d410f 233 K_xy = 0;
saloutos 16:f9ea2b2d410f 234 D_xy = 0;
saloutos 16:f9ea2b2d410f 235 }
saloutos 16:f9ea2b2d410f 236 teff = 0;
saloutos 16:f9ea2b2d410f 237 }
saloutos 16:f9ea2b2d410f 238 else if (t < start_period + traj_period)
saloutos 16:f9ea2b2d410f 239 {
saloutos 16:f9ea2b2d410f 240 K_xx = input_params[5]; // Foot stiffness N/m
saloutos 16:f9ea2b2d410f 241 K_yy = input_params[6]; // Foot stiffness N/m
saloutos 16:f9ea2b2d410f 242 K_xy = input_params[7]; // Foot stiffness N/m
saloutos 16:f9ea2b2d410f 243 D_xx = input_params[8]; // Foot damping N/(m/s)
saloutos 16:f9ea2b2d410f 244 D_yy = input_params[9]; // Foot damping N/(m/s)
saloutos 16:f9ea2b2d410f 245 D_xy = input_params[10]; // Foot damping N/(m/s)
saloutos 16:f9ea2b2d410f 246 teff = (t-start_period);
saloutos 16:f9ea2b2d410f 247 vMult = 1;
saloutos 16:f9ea2b2d410f 248 }
elijahsj 4:7a1b35f081bb 249 else
saloutos 16:f9ea2b2d410f 250 {
saloutos 17:1bb5aa45826e 251 teff = traj_period;
saloutos 17:1bb5aa45826e 252 vMult = 0;
saloutos 16:f9ea2b2d410f 253 }
saloutos 16:f9ea2b2d410f 254
saloutos 16:f9ea2b2d410f 255 float rDesFoot[2] , vDesFoot[2];
saloutos 16:f9ea2b2d410f 256 rDesFoot_bez.evaluate(teff/traj_period,rDesFoot);
saloutos 16:f9ea2b2d410f 257 rDesFoot_bez.evaluateDerivative(teff/traj_period,vDesFoot);
saloutos 16:f9ea2b2d410f 258 vDesFoot[0]/=traj_period;
saloutos 16:f9ea2b2d410f 259 vDesFoot[1]/=traj_period;
saloutos 16:f9ea2b2d410f 260 vDesFoot[0]*=vMult;
saloutos 16:f9ea2b2d410f 261 vDesFoot[1]*=vMult;
saloutos 17:1bb5aa45826e 262
saloutos 17:1bb5aa45826e 263 // Calculate the inverse kinematics (joint positions and velocities) for desired joint angles
saloutos 17:1bb5aa45826e 264 // float th1_des = 0;
saloutos 17:1bb5aa45826e 265 // float th2_des = 0;
saloutos 17:1bb5aa45826e 266 // float dth1_des = 0;
saloutos 17:1bb5aa45826e 267 // float dth2_des = 0;
saloutos 17:1bb5aa45826e 268
saloutos 17:1bb5aa45826e 269 float l_OE = sqrt( (pow(xFoot,2) + pow(yFoot,2)) );
saloutos 17:1bb5aa45826e 270 float alpha = abs(acos( (pow(l_OE,2) - pow(l_AC,2) - pow((l_OB+l_DE),2))/(-2.0f*l_AC*(l_OB+l_DE)) ));
saloutos 17:1bb5aa45826e 271 float th2_des = 3.14159f - alpha;
saloutos 17:1bb5aa45826e 272 float th1_des = (3.14159f/2.0f) + atan2(yFoot,xFoot) - abs(asin( (l_AC/l_OE)*sin(alpha) ));
saloutos 17:1bb5aa45826e 273
saloutos 17:1bb5aa45826e 274 float dd = (Jx_th1*Jy_th2 - Jx_th2*Jy_th1);
saloutos 17:1bb5aa45826e 275 float dth1_des = (1.0f/dd) * ( Jy_th2*vDesFoot[0] - Jx_th2*vDesFoot[1] );
saloutos 17:1bb5aa45826e 276 float dth2_des = (1.0f/dd) * ( -Jy_th1*vDesFoot[0] + Jx_th1*vDesFoot[1] );
saloutos 17:1bb5aa45826e 277
saloutos 16:f9ea2b2d410f 278 // Calculate error variables
saloutos 17:1bb5aa45826e 279 // float e_x = 0;
saloutos 17:1bb5aa45826e 280 // float e_y = 0;
saloutos 17:1bb5aa45826e 281 // float de_x = 0;
saloutos 17:1bb5aa45826e 282 // float de_y = 0;
saloutos 16:f9ea2b2d410f 283
saloutos 17:1bb5aa45826e 284 float e_x = ( xFoot - rDesFoot[0]);
saloutos 17:1bb5aa45826e 285 float e_y = ( yFoot - rDesFoot[1]);
saloutos 17:1bb5aa45826e 286 float de_x = ( dxFoot - vDesFoot[0]);
saloutos 17:1bb5aa45826e 287 float de_y = ( dyFoot - vDesFoot[1]);
saloutos 17:1bb5aa45826e 288
saloutos 16:f9ea2b2d410f 289 // Calculate virtual force on foot
saloutos 17:1bb5aa45826e 290 // float fx = 0;
saloutos 17:1bb5aa45826e 291 // float fy = 0;
saloutos 16:f9ea2b2d410f 292
saloutos 17:1bb5aa45826e 293 float fx = -K_xx * e_x - K_xy * e_y - D_xx * de_x -D_xy * de_y;
saloutos 17:1bb5aa45826e 294 float fy = -K_yy * e_y - K_xy * e_x - D_yy * de_y -D_xy * de_x;
elijahsj 13:3a1f4e09789b 295
saloutos 16:f9ea2b2d410f 296 // Set desired currents
saloutos 17:1bb5aa45826e 297 // current_des1 = 0;
saloutos 17:1bb5aa45826e 298 // current_des2 = 0;
saloutos 16:f9ea2b2d410f 299
saloutos 17:1bb5aa45826e 300 // Joint impedance
saloutos 17:1bb5aa45826e 301 // sub Kxx for K1, Dxx for D1, Kyy for K2, Dyy for D2
saloutos 17:1bb5aa45826e 302 // current_des1 = (-K_xx*(th1) - D_xx*(dth1))/k_t;
saloutos 17:1bb5aa45826e 303 // current_des2 = (-K_yy*(th2) - D_yy*(dth2))/k_t;
saloutos 17:1bb5aa45826e 304 current_des1 = (-K_xx*(th1-th1_des) - D_xx*(dth1-dth1_des))/k_t;
saloutos 17:1bb5aa45826e 305 current_des2 = (-K_yy*(th2-th2_des) - D_yy*(dth2-dth2_des))/k_t;
saloutos 17:1bb5aa45826e 306
saloutos 17:1bb5aa45826e 307 // Cartesian impedance
saloutos 17:1bb5aa45826e 308 // current_des1 = (Jx_th1*fx + Jy_th1*fy)/k_t;
saloutos 17:1bb5aa45826e 309 // current_des2 = (Jx_th2*fx + Jy_th2*fy)/k_t;
saloutos 16:f9ea2b2d410f 310
saloutos 16:f9ea2b2d410f 311 //Form output to send to MATLAB
saloutos 16:f9ea2b2d410f 312 float output_data[NUM_OUTPUTS];
saloutos 16:f9ea2b2d410f 313 // current time
pwensing 0:43448bf056e8 314 output_data[0] = t.read();
saloutos 16:f9ea2b2d410f 315 // motor 1 state
saloutos 16:f9ea2b2d410f 316 output_data[1] = angle1;
saloutos 16:f9ea2b2d410f 317 output_data[2] = velocity1;
saloutos 16:f9ea2b2d410f 318 output_data[3] = current1;
saloutos 16:f9ea2b2d410f 319 output_data[4] = current_des1;
saloutos 16:f9ea2b2d410f 320 output_data[5] = duty_cycle1;
saloutos 16:f9ea2b2d410f 321 // motor 2 state
saloutos 16:f9ea2b2d410f 322 output_data[6] = angle2;
saloutos 16:f9ea2b2d410f 323 output_data[7] = velocity2;
saloutos 16:f9ea2b2d410f 324 output_data[8] = current2;
saloutos 16:f9ea2b2d410f 325 output_data[9] = current_des2;
saloutos 16:f9ea2b2d410f 326 output_data[10]= duty_cycle2;
saloutos 16:f9ea2b2d410f 327 // foot state
saloutos 16:f9ea2b2d410f 328 output_data[11] = xFoot;
saloutos 16:f9ea2b2d410f 329 output_data[12] = yFoot;
saloutos 17:1bb5aa45826e 330 output_data[13] = dxFoot;
saloutos 17:1bb5aa45826e 331 output_data[14] = dyFoot;
saloutos 17:1bb5aa45826e 332 output_data[15] = rDesFoot[0];
saloutos 17:1bb5aa45826e 333 output_data[16] = rDesFoot[1];
saloutos 17:1bb5aa45826e 334 output_data[17] = vDesFoot[0];
saloutos 17:1bb5aa45826e 335 output_data[18] = vDesFoot[1];
elijahsj 13:3a1f4e09789b 336
pwensing 0:43448bf056e8 337 // Send data to MATLAB
pwensing 0:43448bf056e8 338 server.sendData(output_data,NUM_OUTPUTS);
saloutos 16:f9ea2b2d410f 339
saloutos 16:f9ea2b2d410f 340 wait_us(impedance_control_period_us);
elijahsj 4:7a1b35f081bb 341 }
saloutos 16:f9ea2b2d410f 342
pwensing 0:43448bf056e8 343 // Cleanup after experiment
pwensing 0:43448bf056e8 344 server.setExperimentComplete();
saloutos 16:f9ea2b2d410f 345 currentLoop.detach();
elijahsj 12:84a6dcb60422 346 motorShield.motorAWrite(0, 0); //turn motor A off
saloutos 16:f9ea2b2d410f 347 motorShield.motorBWrite(0, 0); //turn motor B off
saloutos 16:f9ea2b2d410f 348
pwensing 0:43448bf056e8 349 } // end if
saloutos 16:f9ea2b2d410f 350
pwensing 0:43448bf056e8 351 } // end while
elijahsj 10:a40d180c305c 352
elijahsj 6:1faceb53dabe 353 } // end main
elijahsj 6:1faceb53dabe 354