Sridevi Kaza / Mbed OS project

nov 18th

Dependencies:   Bezier_Traj_Follower_Example ExperimentServer QEI_pmw MotorShield

main.cpp@18:21c8d94eddee, 2020-09-25 (annotated)

Committer:
saloutos
Date:
Fri Sep 25 15:11:05 2020 +0000
Revision:
18:21c8d94eddee
Parent:
17:1bb5aa45826e
Child:
19:562c08086d71
Updated current controller, debugged inverse kinematics

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 18:21c8d94eddee 65 float current_Kp = 4.0f; //4.0f;
saloutos 18:21c8d94eddee 66 float current_Ki = 0.4f; //0.4f;
saloutos 18:21c8d94eddee 67 float current_int_max = 3.0f; //3.0f;
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 18:21c8d94eddee 78 float R = 2.0f; // motor resistance
saloutos 18:21c8d94eddee 79 float k_t = 0.18f; // 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 18:21c8d94eddee 90 current1 = -(((float(motorShield.readCurrentA())/65536.0f)*30.0f)-15.0f); // measure current
saloutos 18:21c8d94eddee 91 velocity1 = encoderA.getVelocity() * PULSE_TO_RAD; // measure velocity
saloutos 18:21c8d94eddee 92 float err_c1 = current_des1 - current1; // current errror
saloutos 18:21c8d94eddee 93 current_int1 += err_c1; // integrate error
saloutos 18:21c8d94eddee 94 current_int1 = fmaxf( fminf(current_int1, current_int_max), -current_int_max); // anti-windup
saloutos 18:21c8d94eddee 95 float ff1 = R*current_des1 + k_t*velocity1; // feedforward terms
saloutos 18:21c8d94eddee 96 duty_cycle1 = (ff1 + current_Kp*err_c1 + current_Ki*current_int1)/supply_voltage; // PI current controller
saloutos 16:f9ea2b2d410f 97
saloutos 16:f9ea2b2d410f 98 float absDuty1 = abs(duty_cycle1);
saloutos 16:f9ea2b2d410f 99 if (absDuty1 > duty_max) {
saloutos 16:f9ea2b2d410f 100 duty_cycle1 *= duty_max / absDuty1;
saloutos 16:f9ea2b2d410f 101 absDuty1 = duty_max;
saloutos 16:f9ea2b2d410f 102 }
saloutos 16:f9ea2b2d410f 103 if (duty_cycle1 < 0) { // backwards
saloutos 16:f9ea2b2d410f 104 motorShield.motorAWrite(absDuty1, 1);
saloutos 16:f9ea2b2d410f 105 } else { // forwards
saloutos 16:f9ea2b2d410f 106 motorShield.motorAWrite(absDuty1, 0);
saloutos 16:f9ea2b2d410f 107 }
saloutos 16:f9ea2b2d410f 108 prev_current_des1 = current_des1;
saloutos 16:f9ea2b2d410f 109
saloutos 18:21c8d94eddee 110 current2 = -(((float(motorShield.readCurrentB())/65536.0f)*30.0f)-15.0f); // measure current
saloutos 18:21c8d94eddee 111 velocity2 = encoderB.getVelocity() * PULSE_TO_RAD; // measure velocity
saloutos 18:21c8d94eddee 112 float err_c2 = current_des2 - current2; // current error
saloutos 18:21c8d94eddee 113 current_int2 += err_c2; // integrate error
saloutos 18:21c8d94eddee 114 current_int2 = fmaxf( fminf(current_int2, current_int_max), -current_int_max); // anti-windup
saloutos 18:21c8d94eddee 115 float ff2 = R*current_des2 + k_t*velocity2; // feedforward terms
saloutos 18:21c8d94eddee 116 duty_cycle2 = (ff2 + current_Kp*err_c2 + current_Ki*current_int2)/supply_voltage; // PI current controller
saloutos 16:f9ea2b2d410f 117
saloutos 16:f9ea2b2d410f 118 float absDuty2 = abs(duty_cycle2);
saloutos 16:f9ea2b2d410f 119 if (absDuty2 > duty_max) {
saloutos 16:f9ea2b2d410f 120 duty_cycle2 *= duty_max / absDuty2;
saloutos 16:f9ea2b2d410f 121 absDuty2 = duty_max;
saloutos 16:f9ea2b2d410f 122 }
saloutos 16:f9ea2b2d410f 123 if (duty_cycle2 < 0) { // backwards
saloutos 16:f9ea2b2d410f 124 motorShield.motorBWrite(absDuty2, 1);
saloutos 16:f9ea2b2d410f 125 } else { // forwards
saloutos 16:f9ea2b2d410f 126 motorShield.motorBWrite(absDuty2, 0);
saloutos 16:f9ea2b2d410f 127 }
saloutos 16:f9ea2b2d410f 128 prev_current_des2 = current_des2;
saloutos 16:f9ea2b2d410f 129
saloutos 16:f9ea2b2d410f 130 }
elijahsj 6:1faceb53dabe 131
elijahsj 4:7a1b35f081bb 132 int main (void)
elijahsj 4:7a1b35f081bb 133 {
saloutos 17:1bb5aa45826e 134
saloutos 17:1bb5aa45826e 135 // Object for 7th order Cartesian foot trajectory
saloutos 17:1bb5aa45826e 136 BezierCurve rDesFoot_bez(2,BEZIER_ORDER_FOOT);
saloutos 17:1bb5aa45826e 137
pwensing 0:43448bf056e8 138 // Link the terminal with our server and start it up
pwensing 0:43448bf056e8 139 server.attachTerminal(pc);
pwensing 0:43448bf056e8 140 server.init();
elijahsj 13:3a1f4e09789b 141
pwensing 0:43448bf056e8 142 // Continually get input from MATLAB and run experiments
pwensing 0:43448bf056e8 143 float input_params[NUM_INPUTS];
elijahsj 5:1ab9b2527794 144 pc.printf("%f",input_params[0]);
elijahsj 5:1ab9b2527794 145
pwensing 0:43448bf056e8 146 while(1) {
saloutos 16:f9ea2b2d410f 147
saloutos 16:f9ea2b2d410f 148 // If there are new inputs, this code will run
pwensing 0:43448bf056e8 149 if (server.getParams(input_params,NUM_INPUTS)) {
saloutos 16:f9ea2b2d410f 150
saloutos 16:f9ea2b2d410f 151
saloutos 17:1bb5aa45826e 152 // Get inputs from MATLAB
saloutos 16:f9ea2b2d410f 153 start_period = input_params[0]; // First buffer time, before trajectory
saloutos 16:f9ea2b2d410f 154 traj_period = input_params[1]; // Trajectory time/length
saloutos 16:f9ea2b2d410f 155 end_period = input_params[2]; // Second buffer time, after trajectory
saloutos 16:f9ea2b2d410f 156
saloutos 16:f9ea2b2d410f 157 angle1_init = input_params[3]; // Initial angle for q1 (rad)
saloutos 16:f9ea2b2d410f 158 angle2_init = input_params[4]; // Initial angle for q2 (rad)
elijahsj 4:7a1b35f081bb 159
saloutos 16:f9ea2b2d410f 160 K_xx = input_params[5]; // Foot stiffness N/m
saloutos 16:f9ea2b2d410f 161 K_yy = input_params[6]; // Foot stiffness N/m
saloutos 16:f9ea2b2d410f 162 K_xy = input_params[7]; // Foot stiffness N/m
saloutos 16:f9ea2b2d410f 163 D_xx = input_params[8]; // Foot damping N/(m/s)
saloutos 17:1bb5aa45826e 164 D_yy = input_params[9]; // Foot damping N/(m/s)
saloutos 16:f9ea2b2d410f 165 D_xy = input_params[10]; // Foot damping N/(m/s)
saloutos 16:f9ea2b2d410f 166 duty_max = input_params[11]; // Maximum duty factor
saloutos 16:f9ea2b2d410f 167
saloutos 16:f9ea2b2d410f 168 // TODO: check that this gets inputs correctly?
saloutos 16:f9ea2b2d410f 169 float foot_pts[2*(BEZIER_ORDER_FOOT+1)];
saloutos 16:f9ea2b2d410f 170 for(int i = 0; i<2*(BEZIER_ORDER_FOOT+1);i++) {
saloutos 17:1bb5aa45826e 171 foot_pts[i] = input_params[12+i];
saloutos 16:f9ea2b2d410f 172 }
saloutos 16:f9ea2b2d410f 173 rDesFoot_bez.setPoints(foot_pts);
saloutos 16:f9ea2b2d410f 174
saloutos 16:f9ea2b2d410f 175 // Attach current loop interrupt
saloutos 16:f9ea2b2d410f 176 currentLoop.attach_us(CurrentLoop,current_control_period_us);
saloutos 16:f9ea2b2d410f 177
pwensing 0:43448bf056e8 178 // Setup experiment
pwensing 0:43448bf056e8 179 t.reset();
pwensing 0:43448bf056e8 180 t.start();
elijahsj 5:1ab9b2527794 181 encoderA.reset();
elijahsj 5:1ab9b2527794 182 encoderB.reset();
elijahsj 5:1ab9b2527794 183 encoderC.reset();
elijahsj 5:1ab9b2527794 184 encoderD.reset();
elijahsj 10:a40d180c305c 185
elijahsj 15:495333b2ccf1 186 motorShield.motorAWrite(0, 0); //turn motor A off
saloutos 16:f9ea2b2d410f 187 motorShield.motorBWrite(0, 0); //turn motor B off
saloutos 16:f9ea2b2d410f 188
pwensing 0:43448bf056e8 189 // Run experiment
saloutos 16:f9ea2b2d410f 190 while( t.read() < start_period + traj_period + end_period) {
saloutos 16:f9ea2b2d410f 191
saloutos 17:1bb5aa45826e 192 // Read encoders to get motor states, multiply by negative to match defined generalized coordinates
saloutos 16:f9ea2b2d410f 193 angle1 = encoderA.getPulses() *PULSE_TO_RAD + angle1_init;
saloutos 16:f9ea2b2d410f 194 velocity1 = encoderA.getVelocity() * PULSE_TO_RAD;
saloutos 16:f9ea2b2d410f 195
saloutos 16:f9ea2b2d410f 196 angle2 = encoderB.getPulses() * PULSE_TO_RAD + angle2_init;
saloutos 16:f9ea2b2d410f 197 velocity2 = encoderB.getVelocity() * PULSE_TO_RAD;
saloutos 16:f9ea2b2d410f 198
saloutos 16:f9ea2b2d410f 199 const float th1 = angle1;
saloutos 16:f9ea2b2d410f 200 const float th2 = angle2;
saloutos 16:f9ea2b2d410f 201 const float dth1= velocity1;
saloutos 16:f9ea2b2d410f 202 const float dth2= velocity2;
saloutos 16:f9ea2b2d410f 203
saloutos 16:f9ea2b2d410f 204 // ADD YOUR CONTROL CODE HERE (CALCULATE AND SET DESIRED CURRENTS)
saloutos 16:f9ea2b2d410f 205
saloutos 16:f9ea2b2d410f 206 // Calculate the Jacobian
saloutos 17:1bb5aa45826e 207 // float Jx_th1 = 0;
saloutos 17:1bb5aa45826e 208 // float Jx_th2 = 0;
saloutos 17:1bb5aa45826e 209 // float Jy_th1 = 0;
saloutos 17:1bb5aa45826e 210 // float Jy_th2 = 0;
saloutos 17:1bb5aa45826e 211
saloutos 17:1bb5aa45826e 212 float Jx_th1 = l_AC*cos(th1 + th2) + l_DE*cos(th1) + l_OB*cos(th1);
saloutos 17:1bb5aa45826e 213 float Jx_th2 = l_AC*cos(th1 + th2);
saloutos 17:1bb5aa45826e 214 float Jy_th1 = l_AC*sin(th1 + th2) + l_DE*sin(th1) + l_OB*sin(th1);
saloutos 17:1bb5aa45826e 215 float Jy_th2 = l_AC*sin(th1 + th2);
saloutos 16:f9ea2b2d410f 216
saloutos 17:1bb5aa45826e 217 // Calculate the forward kinematics (position and velocity)
saloutos 17:1bb5aa45826e 218 // float xFoot = 0;
saloutos 17:1bb5aa45826e 219 // float yFoot = 0;
saloutos 17:1bb5aa45826e 220 // float dxFoot = 0;
saloutos 17:1bb5aa45826e 221 // float dyFoot = 0;
saloutos 17:1bb5aa45826e 222
saloutos 17:1bb5aa45826e 223 float xFoot = l_AC*sin(th1 + th2) + l_DE*sin(th1) + l_OB*sin(th1);
saloutos 17:1bb5aa45826e 224 float yFoot = - l_AC*cos(th1 + th2) - l_DE*cos(th1) - l_OB*cos(th1);
saloutos 17:1bb5aa45826e 225 float dxFoot = Jx_th1 * dth1 + Jx_th2 * dth2;
saloutos 17:1bb5aa45826e 226 float dyFoot = Jy_th1 * dth1 + Jy_th2 * dth2;
saloutos 16:f9ea2b2d410f 227
saloutos 16:f9ea2b2d410f 228 // Set gains based on buffer and traj times, then calculate desired x,y from Bezier trajectory at current time if necessary
saloutos 16:f9ea2b2d410f 229 float teff = 0;
saloutos 16:f9ea2b2d410f 230 float vMult = 0;
saloutos 16:f9ea2b2d410f 231 if( t < start_period) {
saloutos 16:f9ea2b2d410f 232 if (K_xx > 0 || K_yy > 0) {
saloutos 18:21c8d94eddee 233 K_xx = 1.0f; //50; // TODO: for joint space control, set this to 1
saloutos 18:21c8d94eddee 234 K_yy = 1.0f; //50; // for joint space control, set this to 1
saloutos 18:21c8d94eddee 235 D_xx = 0.1f; //2; // for joint space control, set this to 0.1
saloutos 18:21c8d94eddee 236 D_yy = 0.1f; //2; // for joint space control, set this to 0.1
saloutos 16:f9ea2b2d410f 237 K_xy = 0;
saloutos 16:f9ea2b2d410f 238 D_xy = 0;
saloutos 16:f9ea2b2d410f 239 }
saloutos 16:f9ea2b2d410f 240 teff = 0;
saloutos 16:f9ea2b2d410f 241 }
saloutos 16:f9ea2b2d410f 242 else if (t < start_period + traj_period)
saloutos 16:f9ea2b2d410f 243 {
saloutos 16:f9ea2b2d410f 244 K_xx = input_params[5]; // Foot stiffness N/m
saloutos 16:f9ea2b2d410f 245 K_yy = input_params[6]; // Foot stiffness N/m
saloutos 16:f9ea2b2d410f 246 K_xy = input_params[7]; // Foot stiffness N/m
saloutos 16:f9ea2b2d410f 247 D_xx = input_params[8]; // Foot damping N/(m/s)
saloutos 16:f9ea2b2d410f 248 D_yy = input_params[9]; // Foot damping N/(m/s)
saloutos 16:f9ea2b2d410f 249 D_xy = input_params[10]; // Foot damping N/(m/s)
saloutos 16:f9ea2b2d410f 250 teff = (t-start_period);
saloutos 16:f9ea2b2d410f 251 vMult = 1;
saloutos 16:f9ea2b2d410f 252 }
elijahsj 4:7a1b35f081bb 253 else
saloutos 16:f9ea2b2d410f 254 {
saloutos 17:1bb5aa45826e 255 teff = traj_period;
saloutos 17:1bb5aa45826e 256 vMult = 0;
saloutos 16:f9ea2b2d410f 257 }
saloutos 16:f9ea2b2d410f 258
saloutos 16:f9ea2b2d410f 259 float rDesFoot[2] , vDesFoot[2];
saloutos 16:f9ea2b2d410f 260 rDesFoot_bez.evaluate(teff/traj_period,rDesFoot);
saloutos 16:f9ea2b2d410f 261 rDesFoot_bez.evaluateDerivative(teff/traj_period,vDesFoot);
saloutos 16:f9ea2b2d410f 262 vDesFoot[0]/=traj_period;
saloutos 16:f9ea2b2d410f 263 vDesFoot[1]/=traj_period;
saloutos 16:f9ea2b2d410f 264 vDesFoot[0]*=vMult;
saloutos 16:f9ea2b2d410f 265 vDesFoot[1]*=vMult;
saloutos 17:1bb5aa45826e 266
saloutos 17:1bb5aa45826e 267 // Calculate the inverse kinematics (joint positions and velocities) for desired joint angles
saloutos 17:1bb5aa45826e 268 // float th1_des = 0;
saloutos 17:1bb5aa45826e 269 // float th2_des = 0;
saloutos 17:1bb5aa45826e 270 // float dth1_des = 0;
saloutos 17:1bb5aa45826e 271 // float dth2_des = 0;
saloutos 17:1bb5aa45826e 272
saloutos 18:21c8d94eddee 273 float xFootd = -rDesFoot[0];
saloutos 18:21c8d94eddee 274 float yFootd = rDesFoot[1];
saloutos 18:21c8d94eddee 275 float l_OE = sqrt( (pow(xFootd,2) + pow(yFootd,2)) );
saloutos 17:1bb5aa45826e 276 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 18:21c8d94eddee 277 float th2_des = -(3.14159f - alpha);
saloutos 18:21c8d94eddee 278 float th1_des = -((3.14159f/2.0f) + atan2(yFootd,xFootd) - abs(asin( (l_AC/l_OE)*sin(alpha) )));
saloutos 17:1bb5aa45826e 279
saloutos 17:1bb5aa45826e 280 float dd = (Jx_th1*Jy_th2 - Jx_th2*Jy_th1);
saloutos 17:1bb5aa45826e 281 float dth1_des = (1.0f/dd) * ( Jy_th2*vDesFoot[0] - Jx_th2*vDesFoot[1] );
saloutos 17:1bb5aa45826e 282 float dth2_des = (1.0f/dd) * ( -Jy_th1*vDesFoot[0] + Jx_th1*vDesFoot[1] );
saloutos 17:1bb5aa45826e 283
saloutos 16:f9ea2b2d410f 284 // Calculate error variables
saloutos 17:1bb5aa45826e 285 // float e_x = 0;
saloutos 17:1bb5aa45826e 286 // float e_y = 0;
saloutos 17:1bb5aa45826e 287 // float de_x = 0;
saloutos 17:1bb5aa45826e 288 // float de_y = 0;
saloutos 16:f9ea2b2d410f 289
saloutos 17:1bb5aa45826e 290 float e_x = ( xFoot - rDesFoot[0]);
saloutos 17:1bb5aa45826e 291 float e_y = ( yFoot - rDesFoot[1]);
saloutos 17:1bb5aa45826e 292 float de_x = ( dxFoot - vDesFoot[0]);
saloutos 17:1bb5aa45826e 293 float de_y = ( dyFoot - vDesFoot[1]);
saloutos 17:1bb5aa45826e 294
saloutos 16:f9ea2b2d410f 295 // Calculate virtual force on foot
saloutos 17:1bb5aa45826e 296 // float fx = 0;
saloutos 17:1bb5aa45826e 297 // float fy = 0;
saloutos 18:21c8d94eddee 298
saloutos 17:1bb5aa45826e 299 float fx = -K_xx * e_x - K_xy * e_y - D_xx * de_x -D_xy * de_y;
saloutos 17:1bb5aa45826e 300 float fy = -K_yy * e_y - K_xy * e_x - D_yy * de_y -D_xy * de_x;
elijahsj 13:3a1f4e09789b 301
saloutos 16:f9ea2b2d410f 302 // Set desired currents
saloutos 17:1bb5aa45826e 303 // current_des1 = 0;
saloutos 17:1bb5aa45826e 304 // current_des2 = 0;
saloutos 16:f9ea2b2d410f 305
saloutos 17:1bb5aa45826e 306 // Joint impedance
saloutos 17:1bb5aa45826e 307 // sub Kxx for K1, Dxx for D1, Kyy for K2, Dyy for D2
saloutos 17:1bb5aa45826e 308 // current_des1 = (-K_xx*(th1) - D_xx*(dth1))/k_t;
saloutos 17:1bb5aa45826e 309 // current_des2 = (-K_yy*(th2) - D_yy*(dth2))/k_t;
saloutos 17:1bb5aa45826e 310 current_des1 = (-K_xx*(th1-th1_des) - D_xx*(dth1-dth1_des))/k_t;
saloutos 17:1bb5aa45826e 311 current_des2 = (-K_yy*(th2-th2_des) - D_yy*(dth2-dth2_des))/k_t;
saloutos 17:1bb5aa45826e 312
saloutos 17:1bb5aa45826e 313 // Cartesian impedance
saloutos 17:1bb5aa45826e 314 // current_des1 = (Jx_th1*fx + Jy_th1*fy)/k_t;
saloutos 17:1bb5aa45826e 315 // current_des2 = (Jx_th2*fx + Jy_th2*fy)/k_t;
saloutos 16:f9ea2b2d410f 316
saloutos 16:f9ea2b2d410f 317 //Form output to send to MATLAB
saloutos 16:f9ea2b2d410f 318 float output_data[NUM_OUTPUTS];
saloutos 16:f9ea2b2d410f 319 // current time
pwensing 0:43448bf056e8 320 output_data[0] = t.read();
saloutos 16:f9ea2b2d410f 321 // motor 1 state
saloutos 16:f9ea2b2d410f 322 output_data[1] = angle1;
saloutos 16:f9ea2b2d410f 323 output_data[2] = velocity1;
saloutos 16:f9ea2b2d410f 324 output_data[3] = current1;
saloutos 16:f9ea2b2d410f 325 output_data[4] = current_des1;
saloutos 16:f9ea2b2d410f 326 output_data[5] = duty_cycle1;
saloutos 16:f9ea2b2d410f 327 // motor 2 state
saloutos 16:f9ea2b2d410f 328 output_data[6] = angle2;
saloutos 16:f9ea2b2d410f 329 output_data[7] = velocity2;
saloutos 16:f9ea2b2d410f 330 output_data[8] = current2;
saloutos 16:f9ea2b2d410f 331 output_data[9] = current_des2;
saloutos 16:f9ea2b2d410f 332 output_data[10]= duty_cycle2;
saloutos 16:f9ea2b2d410f 333 // foot state
saloutos 16:f9ea2b2d410f 334 output_data[11] = xFoot;
saloutos 16:f9ea2b2d410f 335 output_data[12] = yFoot;
saloutos 17:1bb5aa45826e 336 output_data[13] = dxFoot;
saloutos 17:1bb5aa45826e 337 output_data[14] = dyFoot;
saloutos 17:1bb5aa45826e 338 output_data[15] = rDesFoot[0];
saloutos 17:1bb5aa45826e 339 output_data[16] = rDesFoot[1];
saloutos 17:1bb5aa45826e 340 output_data[17] = vDesFoot[0];
saloutos 17:1bb5aa45826e 341 output_data[18] = vDesFoot[1];
elijahsj 13:3a1f4e09789b 342
pwensing 0:43448bf056e8 343 // Send data to MATLAB
pwensing 0:43448bf056e8 344 server.sendData(output_data,NUM_OUTPUTS);
saloutos 16:f9ea2b2d410f 345
saloutos 16:f9ea2b2d410f 346 wait_us(impedance_control_period_us);
elijahsj 4:7a1b35f081bb 347 }
saloutos 16:f9ea2b2d410f 348
pwensing 0:43448bf056e8 349 // Cleanup after experiment
pwensing 0:43448bf056e8 350 server.setExperimentComplete();
saloutos 16:f9ea2b2d410f 351 currentLoop.detach();
elijahsj 12:84a6dcb60422 352 motorShield.motorAWrite(0, 0); //turn motor A off
saloutos 16:f9ea2b2d410f 353 motorShield.motorBWrite(0, 0); //turn motor B off
saloutos 16:f9ea2b2d410f 354
pwensing 0:43448bf056e8 355 } // end if
saloutos 16:f9ea2b2d410f 356
pwensing 0:43448bf056e8 357 } // end while
elijahsj 10:a40d180c305c 358
elijahsj 6:1faceb53dabe 359 } // end main
elijahsj 6:1faceb53dabe 360