Sebastian Uribe / Mbed OS pan_flipping

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Dependencies:   MatrixMath Matrix ExperimentServer QEI_pmw MotorShield

main.cpp@34:9a24d0f718ac, 2020-11-16 (annotated)

Committer:
dgdiaz
Date:
Mon Nov 16 08:23:00 2020 +0000
Revision:
34:9a24d0f718ac
Parent:
32:c60a5d33cd79
Child:
35:88dbfefc1bbb
Cartesian space impedance control working;

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
dgdiaz 34:9a24d0f718ac 11 #define NUM_INPUTS (14 + 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;
dgdiaz 34:9a24d0f718ac 35 float angle_des1;
saloutos 16:f9ea2b2d410f 36 float velocity1;
dgdiaz 34:9a24d0f718ac 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;
dgdiaz 34:9a24d0f718ac 47 float angle_des2;
saloutos 16:f9ea2b2d410f 48 float velocity2;
dgdiaz 34:9a24d0f718ac 49 float velocity_des2;
saloutos 16:f9ea2b2d410f 50 float duty_cycle2;
saloutos 16:f9ea2b2d410f 51 float angle2_init;
saloutos 16:f9ea2b2d410f 52
dgdiaz 34:9a24d0f718ac 53 // Fixed kinematic parameters
dgdiaz 34:9a24d0f718ac 54 const float l_OA=.011;
dgdiaz 34:9a24d0f718ac 55 const float l_OB=.042;
dgdiaz 34:9a24d0f718ac 56 const float l_AC=.096;
dgdiaz 34:9a24d0f718ac 57 const float l_DE=.091;
suribe 32:c60a5d33cd79 58
dgdiaz 34:9a24d0f718ac 59 float l1; //=0.084125;
dgdiaz 34:9a24d0f718ac 60 float l2; //=0.084125;
saloutos 16:f9ea2b2d410f 61
saloutos 16:f9ea2b2d410f 62 // Timing parameters
saloutos 16:f9ea2b2d410f 63 float current_control_period_us = 200.0f; // 5kHz current control loop
saloutos 16:f9ea2b2d410f 64 float impedance_control_period_us = 1000.0f; // 1kHz impedance control loop
saloutos 16:f9ea2b2d410f 65 float start_period, traj_period, end_period;
saloutos 16:f9ea2b2d410f 66
saloutos 16:f9ea2b2d410f 67 // Control parameters
saloutos 19:562c08086d71 68 float current_Kp = 4.0f;
saloutos 19:562c08086d71 69 float current_Ki = 0.4f;
saloutos 19:562c08086d71 70 float current_int_max = 3.0f;
saloutos 16:f9ea2b2d410f 71 float duty_max;
saloutos 16:f9ea2b2d410f 72 float K_xx;
saloutos 16:f9ea2b2d410f 73 float K_yy;
saloutos 16:f9ea2b2d410f 74 float K_xy;
saloutos 16:f9ea2b2d410f 75 float D_xx;
saloutos 16:f9ea2b2d410f 76 float D_xy;
saloutos 16:f9ea2b2d410f 77 float D_yy;
saloutos 16:f9ea2b2d410f 78
saloutos 16:f9ea2b2d410f 79 // Model parameters
saloutos 17:1bb5aa45826e 80 float supply_voltage = 12; // motor supply voltage
saloutos 18:21c8d94eddee 81 float R = 2.0f; // motor resistance
saloutos 18:21c8d94eddee 82 float k_t = 0.18f; // motor torque constant
saloutos 17:1bb5aa45826e 83 float nu = 0.0005; // motor viscous friction
saloutos 16:f9ea2b2d410f 84
saloutos 16:f9ea2b2d410f 85 // Current control interrupt function
saloutos 16:f9ea2b2d410f 86 void CurrentLoop()
saloutos 16:f9ea2b2d410f 87 {
saloutos 19:562c08086d71 88 // This loop sets the motor voltage commands using PI current controllers with feedforward terms.
saloutos 16:f9ea2b2d410f 89
saloutos 16:f9ea2b2d410f 90 //use the motor shield as follows:
saloutos 16:f9ea2b2d410f 91 //motorShield.motorAWrite(DUTY CYCLE, DIRECTION), DIRECTION = 0 is forward, DIRECTION =1 is backwards.
saloutos 16:f9ea2b2d410f 92
dgdiaz 34:9a24d0f718ac 93 current1 = -(((float(motorShield.readCurrentA())/65536.0f)*30.0f)-15.0f); // measure current DO WE NEED TO ADJUST GEAR RATIO HERE?
saloutos 18:21c8d94eddee 94 velocity1 = encoderA.getVelocity() * PULSE_TO_RAD; // measure velocity
saloutos 18:21c8d94eddee 95 float err_c1 = current_des1 - current1; // current errror
saloutos 18:21c8d94eddee 96 current_int1 += err_c1; // integrate error
saloutos 18:21c8d94eddee 97 current_int1 = fmaxf( fminf(current_int1, current_int_max), -current_int_max); // anti-windup
saloutos 18:21c8d94eddee 98 float ff1 = R*current_des1 + k_t*velocity1; // feedforward terms
saloutos 18:21c8d94eddee 99 duty_cycle1 = (ff1 + current_Kp*err_c1 + current_Ki*current_int1)/supply_voltage; // PI current controller
saloutos 16:f9ea2b2d410f 100
saloutos 16:f9ea2b2d410f 101 float absDuty1 = abs(duty_cycle1);
saloutos 16:f9ea2b2d410f 102 if (absDuty1 > duty_max) {
saloutos 16:f9ea2b2d410f 103 duty_cycle1 *= duty_max / absDuty1;
saloutos 16:f9ea2b2d410f 104 absDuty1 = duty_max;
saloutos 16:f9ea2b2d410f 105 }
saloutos 16:f9ea2b2d410f 106 if (duty_cycle1 < 0) { // backwards
saloutos 16:f9ea2b2d410f 107 motorShield.motorAWrite(absDuty1, 1);
saloutos 16:f9ea2b2d410f 108 } else { // forwards
saloutos 16:f9ea2b2d410f 109 motorShield.motorAWrite(absDuty1, 0);
saloutos 16:f9ea2b2d410f 110 }
saloutos 16:f9ea2b2d410f 111 prev_current_des1 = current_des1;
saloutos 16:f9ea2b2d410f 112
dgdiaz 34:9a24d0f718ac 113 current2 = -(((float(motorShield.readCurrentB())/65536.0f)*30.0f)-15.0f); // measure current
saloutos 18:21c8d94eddee 114 velocity2 = encoderB.getVelocity() * PULSE_TO_RAD; // measure velocity
saloutos 18:21c8d94eddee 115 float err_c2 = current_des2 - current2; // current error
saloutos 18:21c8d94eddee 116 current_int2 += err_c2; // integrate error
saloutos 18:21c8d94eddee 117 current_int2 = fmaxf( fminf(current_int2, current_int_max), -current_int_max); // anti-windup
saloutos 18:21c8d94eddee 118 float ff2 = R*current_des2 + k_t*velocity2; // feedforward terms
saloutos 18:21c8d94eddee 119 duty_cycle2 = (ff2 + current_Kp*err_c2 + current_Ki*current_int2)/supply_voltage; // PI current controller
saloutos 16:f9ea2b2d410f 120
saloutos 16:f9ea2b2d410f 121 float absDuty2 = abs(duty_cycle2);
saloutos 16:f9ea2b2d410f 122 if (absDuty2 > duty_max) {
saloutos 16:f9ea2b2d410f 123 duty_cycle2 *= duty_max / absDuty2;
saloutos 16:f9ea2b2d410f 124 absDuty2 = duty_max;
saloutos 16:f9ea2b2d410f 125 }
saloutos 16:f9ea2b2d410f 126 if (duty_cycle2 < 0) { // backwards
saloutos 16:f9ea2b2d410f 127 motorShield.motorBWrite(absDuty2, 1);
saloutos 16:f9ea2b2d410f 128 } else { // forwards
saloutos 16:f9ea2b2d410f 129 motorShield.motorBWrite(absDuty2, 0);
saloutos 16:f9ea2b2d410f 130 }
saloutos 16:f9ea2b2d410f 131 prev_current_des2 = current_des2;
dgdiaz 34:9a24d0f718ac 132
saloutos 16:f9ea2b2d410f 133 }
elijahsj 6:1faceb53dabe 134
elijahsj 4:7a1b35f081bb 135 int main (void)
elijahsj 4:7a1b35f081bb 136 {
dgdiaz 34:9a24d0f718ac 137
saloutos 17:1bb5aa45826e 138 // Object for 7th order Cartesian foot trajectory
saloutos 17:1bb5aa45826e 139 BezierCurve rDesFoot_bez(2,BEZIER_ORDER_FOOT);
saloutos 17:1bb5aa45826e 140
pwensing 0:43448bf056e8 141 // Link the terminal with our server and start it up
pwensing 0:43448bf056e8 142 server.attachTerminal(pc);
pwensing 0:43448bf056e8 143 server.init();
elijahsj 13:3a1f4e09789b 144
pwensing 0:43448bf056e8 145 // Continually get input from MATLAB and run experiments
pwensing 0:43448bf056e8 146 float input_params[NUM_INPUTS];
elijahsj 5:1ab9b2527794 147 pc.printf("%f",input_params[0]);
elijahsj 5:1ab9b2527794 148
pwensing 0:43448bf056e8 149 while(1) {
dgdiaz 34:9a24d0f718ac 150
saloutos 16:f9ea2b2d410f 151 // If there are new inputs, this code will run
pwensing 0:43448bf056e8 152 if (server.getParams(input_params,NUM_INPUTS)) {
dgdiaz 34:9a24d0f718ac 153
dgdiaz 34:9a24d0f718ac 154
suribe 32:c60a5d33cd79 155 // Get inputs from MATLAB
dgdiaz 34:9a24d0f718ac 156 start_period = input_params[0]; // First buffer time, before trajectory
dgdiaz 34:9a24d0f718ac 157 traj_period = input_params[1]; // Trajectory time/length
dgdiaz 34:9a24d0f718ac 158 end_period = input_params[2]; // Second buffer time, after trajectory
saloutos 16:f9ea2b2d410f 159
dgdiaz 34:9a24d0f718ac 160 angle1_init = input_params[3]; // Initial angle for q1 (rad)
dgdiaz 34:9a24d0f718ac 161 angle2_init = input_params[4]; // Initial angle for q2 (rad)
elijahsj 4:7a1b35f081bb 162
dgdiaz 34:9a24d0f718ac 163 K_xx = input_params[5]; // Foot stiffness N/m
dgdiaz 34:9a24d0f718ac 164 K_yy = input_params[6]; // Foot stiffness N/m
dgdiaz 34:9a24d0f718ac 165 K_xy = input_params[7]; // Foot stiffness N/m
dgdiaz 34:9a24d0f718ac 166 D_xx = input_params[8]; // Foot damping N/(m/s)
dgdiaz 34:9a24d0f718ac 167 D_yy = input_params[9]; // Foot damping N/(m/s)
dgdiaz 34:9a24d0f718ac 168 D_xy = input_params[10]; // Foot damping N/(m/s)
dgdiaz 34:9a24d0f718ac 169 duty_max = input_params[11]; // Maximum duty factor
dgdiaz 34:9a24d0f718ac 170 l1 = input_params[12];
dgdiaz 34:9a24d0f718ac 171 l2 = input_params[13];
saloutos 16:f9ea2b2d410f 172
saloutos 19:562c08086d71 173 // Get foot trajectory points
saloutos 16:f9ea2b2d410f 174 float foot_pts[2*(BEZIER_ORDER_FOOT+1)];
saloutos 16:f9ea2b2d410f 175 for(int i = 0; i<2*(BEZIER_ORDER_FOOT+1);i++) {
saloutos 17:1bb5aa45826e 176 foot_pts[i] = input_params[12+i];
saloutos 16:f9ea2b2d410f 177 }
saloutos 16:f9ea2b2d410f 178 rDesFoot_bez.setPoints(foot_pts);
saloutos 16:f9ea2b2d410f 179
saloutos 16:f9ea2b2d410f 180 // Attach current loop interrupt
saloutos 16:f9ea2b2d410f 181 currentLoop.attach_us(CurrentLoop,current_control_period_us);
saloutos 16:f9ea2b2d410f 182
pwensing 0:43448bf056e8 183 // Setup experiment
pwensing 0:43448bf056e8 184 t.reset();
pwensing 0:43448bf056e8 185 t.start();
elijahsj 5:1ab9b2527794 186 encoderA.reset();
elijahsj 5:1ab9b2527794 187 encoderB.reset();
elijahsj 5:1ab9b2527794 188 encoderC.reset();
elijahsj 5:1ab9b2527794 189 encoderD.reset();
elijahsj 10:a40d180c305c 190
elijahsj 15:495333b2ccf1 191 motorShield.motorAWrite(0, 0); //turn motor A off
saloutos 16:f9ea2b2d410f 192 motorShield.motorBWrite(0, 0); //turn motor B off
saloutos 16:f9ea2b2d410f 193
pwensing 0:43448bf056e8 194 // Run experiment
saloutos 16:f9ea2b2d410f 195 while( t.read() < start_period + traj_period + end_period) {
saloutos 16:f9ea2b2d410f 196
saloutos 19:562c08086d71 197 // Read encoders to get motor states
saloutos 16:f9ea2b2d410f 198 angle1 = encoderA.getPulses() *PULSE_TO_RAD + angle1_init;
saloutos 16:f9ea2b2d410f 199 velocity1 = encoderA.getVelocity() * PULSE_TO_RAD;
saloutos 16:f9ea2b2d410f 200
saloutos 16:f9ea2b2d410f 201 angle2 = encoderB.getPulses() * PULSE_TO_RAD + angle2_init;
saloutos 16:f9ea2b2d410f 202 velocity2 = encoderB.getVelocity() * PULSE_TO_RAD;
saloutos 16:f9ea2b2d410f 203
saloutos 16:f9ea2b2d410f 204 const float th1 = angle1;
saloutos 16:f9ea2b2d410f 205 const float th2 = angle2;
saloutos 16:f9ea2b2d410f 206 const float dth1= velocity1;
saloutos 16:f9ea2b2d410f 207 const float dth2= velocity2;
saloutos 16:f9ea2b2d410f 208
saloutos 16:f9ea2b2d410f 209 // Calculate the Jacobian
dgdiaz 34:9a24d0f718ac 210 float Jx_th1 = l1*cos(th1)+l2*cos(th1+th2);
dgdiaz 34:9a24d0f718ac 211 float Jx_th2 = l2*cos(th1+th2);
dgdiaz 34:9a24d0f718ac 212 float Jy_th1 = l1*sin(th1)+l2*sin(th1+th2);
dgdiaz 34:9a24d0f718ac 213 float Jy_th2 = l2*sin(th1+th2);
dgdiaz 34:9a24d0f718ac 214
dgdiaz 34:9a24d0f718ac 215
saloutos 17:1bb5aa45826e 216 // Calculate the forward kinematics (position and velocity)
dgdiaz 34:9a24d0f718ac 217 // float xFoot = l_DE*sin(th1)+l_OB*sin(th1)+l_AC*sin(th1+th2);
dgdiaz 34:9a24d0f718ac 218 // float yFoot = -l_DE*cos(th1)-l_OB*cos(th1)-l_AC*cos(th1+th2);
dgdiaz 34:9a24d0f718ac 219 // float dxFoot = dth1*(l_AC*cos(th1+th2)+l_DE*cos(th1)+l_OB*cos(th1))+dth2*l_AC*cos(th1+th2);
dgdiaz 34:9a24d0f718ac 220 // float dyFoot = dth1*(l_AC*sin(th1+th2)+l_DE*sin(th1)+l_OB*sin(th1))+dth2*l_AC*sin(th1+th2);
dgdiaz 34:9a24d0f718ac 221 float xFoot = l2*sin(th1+th2) + l1*sin(th1);
dgdiaz 34:9a24d0f718ac 222 float yFoot = -l2*cos(th1+th2) - l1*cos(th1);
dgdiaz 34:9a24d0f718ac 223 float dxFoot = l1*cos(th1)*dth1 + l2*cos(th1+th2)*(dth1+dth2);
dgdiaz 34:9a24d0f718ac 224 float dyFoot = l1*sin(th1)*dth1 + l2*sin(th1+th2)*(dth1+dth2);
dgdiaz 34:9a24d0f718ac 225
saloutos 16:f9ea2b2d410f 226 // Set gains based on buffer and traj times, then calculate desired x,y from Bezier trajectory at current time if necessary
saloutos 16:f9ea2b2d410f 227 float teff = 0;
saloutos 16:f9ea2b2d410f 228 float vMult = 0;
saloutos 16:f9ea2b2d410f 229 if( t < start_period) {
dgdiaz 34:9a24d0f718ac 230 if (K_xx > 0 || K_yy > 0) {
dgdiaz 34:9a24d0f718ac 231 // K_xx = 1; // for joint space control, set this to 1
dgdiaz 34:9a24d0f718ac 232 // K_yy = 1; // for joint space control, set this to 1
dgdiaz 34:9a24d0f718ac 233 // D_xx = .1; // for joint space control, set this to 0.1
dgdiaz 34:9a24d0f718ac 234 // D_yy = .1; // for joint space control, set this to 0.1
dgdiaz 34:9a24d0f718ac 235 K_xx = 50; // for joint space control, set this to 1
dgdiaz 34:9a24d0f718ac 236 K_yy = 50; // for joint space control, set this to 1
dgdiaz 34:9a24d0f718ac 237 D_xx = 2; // for joint space control, set this to 0.1
dgdiaz 34:9a24d0f718ac 238 D_yy = 2; // for joint space control, set this to 0.1
saloutos 16:f9ea2b2d410f 239 K_xy = 0;
saloutos 16:f9ea2b2d410f 240 D_xy = 0;
saloutos 16:f9ea2b2d410f 241 }
saloutos 16:f9ea2b2d410f 242 teff = 0;
saloutos 16:f9ea2b2d410f 243 }
saloutos 16:f9ea2b2d410f 244 else if (t < start_period + traj_period)
saloutos 16:f9ea2b2d410f 245 {
dgdiaz 34:9a24d0f718ac 246 K_xx = input_params[5]; // Foot stiffness N/m
dgdiaz 34:9a24d0f718ac 247 K_yy = input_params[6]; // Foot stiffness N/m
dgdiaz 34:9a24d0f718ac 248 K_xy = input_params[7]; // Foot stiffness N/m
dgdiaz 34:9a24d0f718ac 249 D_xx = input_params[8]; // Foot damping N/(m/s)
dgdiaz 34:9a24d0f718ac 250 D_yy = input_params[9]; // Foot damping N/(m/s)
dgdiaz 34:9a24d0f718ac 251 D_xy = input_params[10]; // Foot damping N/(m/s)
saloutos 16:f9ea2b2d410f 252 teff = (t-start_period);
saloutos 16:f9ea2b2d410f 253 vMult = 1;
saloutos 16:f9ea2b2d410f 254 }
elijahsj 4:7a1b35f081bb 255 else
saloutos 16:f9ea2b2d410f 256 {
saloutos 17:1bb5aa45826e 257 teff = traj_period;
saloutos 17:1bb5aa45826e 258 vMult = 0;
saloutos 16:f9ea2b2d410f 259 }
saloutos 16:f9ea2b2d410f 260
saloutos 16:f9ea2b2d410f 261 float rDesFoot[2] , vDesFoot[2];
saloutos 16:f9ea2b2d410f 262 rDesFoot_bez.evaluate(teff/traj_period,rDesFoot);
saloutos 16:f9ea2b2d410f 263 rDesFoot_bez.evaluateDerivative(teff/traj_period,vDesFoot);
saloutos 16:f9ea2b2d410f 264 vDesFoot[0]/=traj_period;
saloutos 16:f9ea2b2d410f 265 vDesFoot[1]/=traj_period;
saloutos 16:f9ea2b2d410f 266 vDesFoot[0]*=vMult;
saloutos 16:f9ea2b2d410f 267 vDesFoot[1]*=vMult;
saloutos 17:1bb5aa45826e 268
saloutos 19:562c08086d71 269 // Calculate the inverse kinematics (joint positions and velocities) for desired joint angles
suribe 29:a88dd750fdbd 270 float xFootd = -rDesFoot[0];
suribe 29:a88dd750fdbd 271 float yFootd = rDesFoot[1];
suribe 29:a88dd750fdbd 272 float l_OE = sqrt( (pow(xFootd,2) + pow(yFootd,2)) );
saloutos 17:1bb5aa45826e 273 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 274 float th2_des = -(3.14159f - alpha);
suribe 29:a88dd750fdbd 275 float th1_des = -((3.14159f/2.0f) + atan2(yFootd,xFootd) - abs(asin( (l_AC/l_OE)*sin(alpha) )));
saloutos 17:1bb5aa45826e 276
saloutos 17:1bb5aa45826e 277 float dd = (Jx_th1*Jy_th2 - Jx_th2*Jy_th1);
saloutos 17:1bb5aa45826e 278 float dth1_des = (1.0f/dd) * ( Jy_th2*vDesFoot[0] - Jx_th2*vDesFoot[1] );
saloutos 17:1bb5aa45826e 279 float dth2_des = (1.0f/dd) * ( -Jy_th1*vDesFoot[0] + Jx_th1*vDesFoot[1] );
saloutos 17:1bb5aa45826e 280
saloutos 16:f9ea2b2d410f 281 // Calculate error variables
dgdiaz 34:9a24d0f718ac 282 float e_x = xFootd-xFoot;
dgdiaz 34:9a24d0f718ac 283 float e_y = yFootd-yFoot;
dgdiaz 34:9a24d0f718ac 284 float de_x = vDesFoot[0]-dxFoot;
dgdiaz 34:9a24d0f718ac 285 float de_y = vDesFoot[1]-dyFoot;
saloutos 17:1bb5aa45826e 286
saloutos 16:f9ea2b2d410f 287 // Calculate virtual force on foot
dgdiaz 34:9a24d0f718ac 288 float fx = K_xx*e_x + K_xy*e_y + D_xx*de_x + D_xy*de_y;
dgdiaz 34:9a24d0f718ac 289 float fy = K_xy*e_x + K_yy*e_y + D_xy*de_x + D_yy*de_y;
saloutos 26:5822d4d8dca7 290
dgdiaz 34:9a24d0f718ac 291 float T1 = Jx_th1*fx+Jy_th1*fy;
dgdiaz 34:9a24d0f718ac 292 float T2 = Jx_th2*fx+Jy_th2*fy;
dgdiaz 34:9a24d0f718ac 293
saloutos 18:21c8d94eddee 294
saloutos 19:562c08086d71 295 // Set desired currents
dgdiaz 34:9a24d0f718ac 296
dgdiaz 34:9a24d0f718ac 297 // Joint impedance
dgdiaz 34:9a24d0f718ac 298 // sub Kxx for K1, Dxx for D1, Kyy for K2, Dyy for D2
dgdiaz 34:9a24d0f718ac 299 // Note: Be careful with signs now that you have non-zero desired angles!
dgdiaz 34:9a24d0f718ac 300 // Your equations should be of the form i_d = K1*(q1_d - q1) + D1*(dq1_d - dq1)
dgdiaz 34:9a24d0f718ac 301 // current_des1 = (K_xx*(th1_des-angle1) + D_xx*(dth1_des-velocity1))/k_t;
dgdiaz 34:9a24d0f718ac 302 // current_des2 = (K_yy*(th2_des-angle2) + D_yy*(dth2_des-velocity2))/k_t;
dgdiaz 34:9a24d0f718ac 303
dgdiaz 34:9a24d0f718ac 304 // Cartesian impedance
dgdiaz 34:9a24d0f718ac 305 // Note: As with the joint space laws, be careful with signs!
dgdiaz 34:9a24d0f718ac 306 current_des1 = T1/k_t;
dgdiaz 34:9a24d0f718ac 307 current_des2 = T2/k_t;
dgdiaz 34:9a24d0f718ac 308
dgdiaz 34:9a24d0f718ac 309
saloutos 19:562c08086d71 310 // Form output to send to MATLAB
saloutos 16:f9ea2b2d410f 311 float output_data[NUM_OUTPUTS];
saloutos 16:f9ea2b2d410f 312 // current time
pwensing 0:43448bf056e8 313 output_data[0] = t.read();
saloutos 16:f9ea2b2d410f 314 // motor 1 state
saloutos 16:f9ea2b2d410f 315 output_data[1] = angle1;
saloutos 16:f9ea2b2d410f 316 output_data[2] = velocity1;
saloutos 16:f9ea2b2d410f 317 output_data[3] = current1;
saloutos 16:f9ea2b2d410f 318 output_data[4] = current_des1;
saloutos 16:f9ea2b2d410f 319 output_data[5] = duty_cycle1;
saloutos 16:f9ea2b2d410f 320 // motor 2 state
saloutos 16:f9ea2b2d410f 321 output_data[6] = angle2;
saloutos 16:f9ea2b2d410f 322 output_data[7] = velocity2;
saloutos 16:f9ea2b2d410f 323 output_data[8] = current2;
saloutos 16:f9ea2b2d410f 324 output_data[9] = current_des2;
saloutos 16:f9ea2b2d410f 325 output_data[10]= duty_cycle2;
saloutos 16:f9ea2b2d410f 326 // foot state
saloutos 16:f9ea2b2d410f 327 output_data[11] = xFoot;
saloutos 16:f9ea2b2d410f 328 output_data[12] = yFoot;
saloutos 17:1bb5aa45826e 329 output_data[13] = dxFoot;
saloutos 17:1bb5aa45826e 330 output_data[14] = dyFoot;
saloutos 17:1bb5aa45826e 331 output_data[15] = rDesFoot[0];
saloutos 17:1bb5aa45826e 332 output_data[16] = rDesFoot[1];
saloutos 17:1bb5aa45826e 333 output_data[17] = vDesFoot[0];
saloutos 17:1bb5aa45826e 334 output_data[18] = vDesFoot[1];
elijahsj 13:3a1f4e09789b 335
pwensing 0:43448bf056e8 336 // Send data to MATLAB
pwensing 0:43448bf056e8 337 server.sendData(output_data,NUM_OUTPUTS);
saloutos 16:f9ea2b2d410f 338
saloutos 16:f9ea2b2d410f 339 wait_us(impedance_control_period_us);
elijahsj 4:7a1b35f081bb 340 }
saloutos 16:f9ea2b2d410f 341
pwensing 0:43448bf056e8 342 // Cleanup after experiment
pwensing 0:43448bf056e8 343 server.setExperimentComplete();
saloutos 16:f9ea2b2d410f 344 currentLoop.detach();
elijahsj 12:84a6dcb60422 345 motorShield.motorAWrite(0, 0); //turn motor A off
saloutos 16:f9ea2b2d410f 346 motorShield.motorBWrite(0, 0); //turn motor B off
dgdiaz 34:9a24d0f718ac 347
pwensing 0:43448bf056e8 348 } // end if
dgdiaz 34:9a24d0f718ac 349
pwensing 0:43448bf056e8 350 } // end while
dgdiaz 34:9a24d0f718ac 351
suribe 32:c60a5d33cd79 352 } // end main