Sebastian Uribe
/
pan_flipping
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Dependencies: MatrixMath Matrix ExperimentServer QEI_pmw MotorShield
Diff: main.cpp
- Revision:
- 34:9a24d0f718ac
- Parent:
- 32:c60a5d33cd79
- Child:
- 35:88dbfefc1bbb
diff -r 2231d77d3d1d -r 9a24d0f718ac main.cpp
--- a/main.cpp Mon Nov 16 05:12:37 2020 +0000
+++ b/main.cpp Mon Nov 16 08:23:00 2020 +0000
@@ -6,11 +6,9 @@
#include "BezierCurve.h"
#include "MotorShield.h"
#include "HardwareSetup.h"
-#include "Matrix.h"
-#include "MatrixMath.h"
#define BEZIER_ORDER_FOOT 7
-#define NUM_INPUTS (12 + 2*(BEZIER_ORDER_FOOT+1))
+#define NUM_INPUTS (14 + 2*(BEZIER_ORDER_FOOT+1))
#define NUM_OUTPUTS 19
#define PULSE_TO_RAD (2.0f*3.14159f / 1200.0f)
@@ -28,20 +26,15 @@
MotorShield motorShield(12000); //initialize the motor shield with a period of 12000 ticks or ~20kHZ
Ticker currentLoop;
-Matrix MassMatrix(2,2);
-Matrix Jacobian(2,2);
-Matrix JacobianT(2,2);
-Matrix InverseMassMatrix(2,2);
-Matrix temp_product(2,2);
-Matrix Lambda(2,2);
-
// Variables for q1
float current1;
float current_des1 = 0;
float prev_current_des1 = 0;
float current_int1 = 0;
float angle1;
+float angle_des1;
float velocity1;
+float velocity_des1;
float duty_cycle1;
float angle1_init;
@@ -51,32 +44,26 @@
float prev_current_des2 = 0;
float current_int2 = 0;
float angle2;
+float angle_des2;
float velocity2;
+float velocity_des2;
float duty_cycle2;
float angle2_init;
+// Fixed kinematic parameters
+const float l_OA=.011;
+const float l_OB=.042;
+const float l_AC=.096;
+const float l_DE=.091;
+float l1; //=0.084125;
+float l2; //=0.084125;
// Timing parameters
float current_control_period_us = 200.0f; // 5kHz current control loop
float impedance_control_period_us = 1000.0f; // 1kHz impedance control loop
float start_period, traj_period, end_period;
-// Hardware kinematic parameters -- NEED PAN PARAMETERS
-const float l_c1; //upper arm center of mass
-const float l_B; //upper arm length
-const float r_c2; //lower arm center of mass
-const float l_C; //lower arm length
-
-const float m1; //mass of upper arm
-const float m2; //mass of lower arm
-
-const float I1; //upper arm interia
-const float I2; //lower arm inertia
-
-const float N; //gear ratio
-const float Ir; //motor inertia
-
// Control parameters
float current_Kp = 4.0f;
float current_Ki = 0.4f;
@@ -103,7 +90,7 @@
//use the motor shield as follows:
//motorShield.motorAWrite(DUTY CYCLE, DIRECTION), DIRECTION = 0 is forward, DIRECTION =1 is backwards.
- current1 = -(((float(motorShield.readCurrentA())/65536.0f)*30.0f)-15.0f); // measure current
+ current1 = -(((float(motorShield.readCurrentA())/65536.0f)*30.0f)-15.0f); // measure current DO WE NEED TO ADJUST GEAR RATIO HERE?
velocity1 = encoderA.getVelocity() * PULSE_TO_RAD; // measure velocity
float err_c1 = current_des1 - current1; // current errror
current_int1 += err_c1; // integrate error
@@ -123,7 +110,7 @@
}
prev_current_des1 = current_des1;
- current2 = -(((float(motorShield.readCurrentB())/65536.0f)*30.0f)-15.0f); // measure current
+ current2 = -(((float(motorShield.readCurrentB())/65536.0f)*30.0f)-15.0f); // measure current
velocity2 = encoderB.getVelocity() * PULSE_TO_RAD; // measure velocity
float err_c2 = current_des2 - current2; // current error
current_int2 += err_c2; // integrate error
@@ -142,10 +129,12 @@
motorShield.motorBWrite(absDuty2, 0);
}
prev_current_des2 = current_des2;
+
}
int main (void)
{
+
// Object for 7th order Cartesian foot trajectory
BezierCurve rDesFoot_bez(2,BEZIER_ORDER_FOOT);
@@ -158,37 +147,28 @@
pc.printf("%f",input_params[0]);
while(1) {
+
// If there are new inputs, this code will run
if (server.getParams(input_params,NUM_INPUTS)) {
+
+
// Get inputs from MATLAB
- start_period = input_params[0]; // First buffer time, before trajectory
- traj_period = input_params[1]; // Trajectory time/length
- end_period = input_params[2]; // Second buffer time, after trajectory
-
- l_c1 = input_params[3]; //upper arm center of mass
- l_B = input_params[4]; //upper arm length
- l_c2 = input_params[5]; //lower arm center of mass
- l_C = input_params[6]; //lower arm length
-
- m1 = input_params[7]; //mass of upper arm
- m2 = input_params[8]; //mass of lower arm
-
- I1 = input_params[9]; //upper arm interia
- I2 = input_params[10]; //lower arm inertia
-
- N = input_params[11]; //gear ratio
- Ir = input_params[12]; //motor inertia
+ start_period = input_params[0]; // First buffer time, before trajectory
+ traj_period = input_params[1]; // Trajectory time/length
+ end_period = input_params[2]; // Second buffer time, after trajectory
- angle1_init = input_params[13]; // Initial angle for q1 (rad)
- angle2_init = input_params[14]; // Initial angle for q2 (rad)
+ angle1_init = input_params[3]; // Initial angle for q1 (rad)
+ angle2_init = input_params[4]; // Initial angle for q2 (rad)
- K_xx = input_params[15]; // Foot stiffness N/m
- K_yy = input_params[16]; // Foot stiffness N/m
- K_xy = input_params[17]; // Foot stiffness N/m
- D_xx = input_params[18]; // Foot damping N/(m/s)
- D_yy = input_params[19]; // Foot damping N/(m/s)
- D_xy = input_params[20]; // Foot damping N/(m/s)
- duty_max = input_params[21]; // Maximum duty factor
+ K_xx = input_params[5]; // Foot stiffness N/m
+ K_yy = input_params[6]; // Foot stiffness N/m
+ K_xy = input_params[7]; // Foot stiffness N/m
+ D_xx = input_params[8]; // Foot damping N/(m/s)
+ D_yy = input_params[9]; // Foot damping N/(m/s)
+ D_xy = input_params[10]; // Foot damping N/(m/s)
+ duty_max = input_params[11]; // Maximum duty factor
+ l1 = input_params[12];
+ l2 = input_params[13];
// Get foot trajectory points
float foot_pts[2*(BEZIER_ORDER_FOOT+1)];
@@ -227,27 +207,35 @@
const float dth2= velocity2;
// Calculate the Jacobian
- float Jx_th1 = l_AC*cos(th1+th2)+l_DE*cos(th1)+l_OB*cos(th1);
- float Jx_th2 = l_AC*cos(th1+th2);
- float Jy_th1 = l_AC*sin(th1+th2)+l_DE*sin(th1)+l_OB*sin(th1);
- float Jy_th2 = l_AC*sin(th1+th2);
-
+ float Jx_th1 = l1*cos(th1)+l2*cos(th1+th2);
+ float Jx_th2 = l2*cos(th1+th2);
+ float Jy_th1 = l1*sin(th1)+l2*sin(th1+th2);
+ float Jy_th2 = l2*sin(th1+th2);
+
+
// Calculate the forward kinematics (position and velocity)
- float xFoot = l_DE*sin(th1)+l_OB*sin(th1)+l_AC*sin(th1+th2);
- float yFoot = -l_DE*cos(th1)-l_OB*cos(th1)-l_AC*cos(th1+th2);
- float dxFoot = dth1*(l_AC*cos(th1+th2)+l_DE*cos(th1)+l_OB*cos(th1))+dth2*l_AC*cos(th1+th2);
- float dyFoot = dth1*(l_AC*sin(th1+th2)+l_DE*sin(th1)+l_OB*sin(th1))+dth2*l_AC*sin(th1+th2);
-
-
+// float xFoot = l_DE*sin(th1)+l_OB*sin(th1)+l_AC*sin(th1+th2);
+// float yFoot = -l_DE*cos(th1)-l_OB*cos(th1)-l_AC*cos(th1+th2);
+// float dxFoot = dth1*(l_AC*cos(th1+th2)+l_DE*cos(th1)+l_OB*cos(th1))+dth2*l_AC*cos(th1+th2);
+// float dyFoot = dth1*(l_AC*sin(th1+th2)+l_DE*sin(th1)+l_OB*sin(th1))+dth2*l_AC*sin(th1+th2);
+ float xFoot = l2*sin(th1+th2) + l1*sin(th1);
+ float yFoot = -l2*cos(th1+th2) - l1*cos(th1);
+ float dxFoot = l1*cos(th1)*dth1 + l2*cos(th1+th2)*(dth1+dth2);
+ float dyFoot = l1*sin(th1)*dth1 + l2*sin(th1+th2)*(dth1+dth2);
+
// Set gains based on buffer and traj times, then calculate desired x,y from Bezier trajectory at current time if necessary
float teff = 0;
float vMult = 0;
if( t < start_period) {
- if (K_xx > 0 || K_yy > 0) {
- K_xx = 100;
- K_yy = 100;
- D_xx = 5;
- D_yy = 5;
+ if (K_xx > 0 || K_yy > 0) {
+// K_xx = 1; // for joint space control, set this to 1
+// K_yy = 1; // for joint space control, set this to 1
+// D_xx = .1; // for joint space control, set this to 0.1
+// D_yy = .1; // for joint space control, set this to 0.1
+ K_xx = 50; // for joint space control, set this to 1
+ K_yy = 50; // for joint space control, set this to 1
+ D_xx = 2; // for joint space control, set this to 0.1
+ D_yy = 2; // for joint space control, set this to 0.1
K_xy = 0;
D_xy = 0;
}
@@ -255,12 +243,12 @@
}
else if (t < start_period + traj_period)
{
- K_xx = input_params[15]; // Foot stiffness N/m
- K_yy = input_params[16]; // Foot stiffness N/m
- K_xy = input_params[17]; // Foot stiffness N/m
- D_xx = input_params[18]; // Foot damping N/(m/s)
- D_yy = input_params[19]; // Foot damping N/(m/s)
- D_xy = input_params[20]; // Foot damping N/(m/s)
+ K_xx = input_params[5]; // Foot stiffness N/m
+ K_yy = input_params[6]; // Foot stiffness N/m
+ K_xy = input_params[7]; // Foot stiffness N/m
+ D_xx = input_params[8]; // Foot damping N/(m/s)
+ D_yy = input_params[9]; // Foot damping N/(m/s)
+ D_xy = input_params[10]; // Foot damping N/(m/s)
teff = (t-start_period);
vMult = 1;
}
@@ -270,7 +258,6 @@
vMult = 0;
}
- // Get desired foot positions and velocities
float rDesFoot[2] , vDesFoot[2];
rDesFoot_bez.evaluate(teff/traj_period,rDesFoot);
rDesFoot_bez.evaluateDerivative(teff/traj_period,vDesFoot);
@@ -292,57 +279,34 @@
float dth2_des = (1.0f/dd) * ( -Jy_th1*vDesFoot[0] + Jx_th1*vDesFoot[1] );
// Calculate error variables
- float e_x = 0;
- float e_y = 0;
- float de_x = 0;
- float de_y = 0;
+ float e_x = xFootd-xFoot;
+ float e_y = yFootd-yFoot;
+ float de_x = vDesFoot[0]-dxFoot;
+ float de_y = vDesFoot[1]-dyFoot;
// Calculate virtual force on foot
- float xdelta = -xFootd - xFoot;
- float ydelta = yFootd - yFoot;
- float dydelta = vDesFoot[1] - dyFoot;
- float dxdelta = vDesFoot[0] - dxFoot;
- float fx = K_xx*xdelta+K_xy*ydelta+D_xx*dxdelta+D_xy*dydelta;
- float fy = K_yy*ydelta+K_xy*xdelta+D_yy*dydelta+D_xy*dxdelta;
-
- float t1 = Jx_th1*fx + Jy_th1*fy;
- float t2 = Jx_th2*fx + Jy_th2*fy;
-
- // Calculate mass matrix elements
- float M11 = I1 + I2 + I3 + I4 + Ir + Ir*N*N + l_AC*l_AC*m4 + l_A_m3*l_A_m3*m3 + l_B_m2*l_B_m2*m2 + l_C_m4*l_C_m4*m4 + l_OA*l_OA*m3 + l_OB*l_OB*m2 + l_OA*l_OA*m4 + l_O_m1*l_O_m1*m1 + 2*l_C_m4*l_OA*m4 + 2*l_AC*l_C_m4*m4*cos(th2) + 2*l_AC*l_OA*m4*cos(th2) + 2*l_A_m3*l_OA*m3*cos(th2) + 2*l_B_m2*l_OB*m2*cos(th2);
- float M12 = I2 + I3 + l_AC*l_AC*m4 + l_A_m3*l_A_m3*m3 + l_B_m2*l_B_m2*m2 + Ir*N + l_AC*l_C_m4*m4*cos(th2) + l_AC*l_OA*m4*cos(th2) + l_A_m3*l_OA*m3*cos(th2) + l_B_m2*l_OB*m2*cos(th2);
- float M22 = Ir*N*N + m4*l_AC*l_AC + m3*l_A_m3*l_A_m3 + m2*l_B_m2*l_B_m2 + I2 + I3;
-
- // Populate mass matrix
- MassMatrix.Clear();
- MassMatrix << M11 << M12
- << M12 << M22;
+ float fx = K_xx*e_x + K_xy*e_y + D_xx*de_x + D_xy*de_y;
+ float fy = K_xy*e_x + K_yy*e_y + D_xy*de_x + D_yy*de_y;
- // Populate Jacobian matrix
- Jacobian.Clear();
- Jacobian << Jx_th1 << Jx_th2
- << Jy_th1 << Jy_th2;
-
- // Calculate Lambda matrix
- JacobianT = MatrixMath::Transpose(Jacobian);
- InverseMassMatrix = MatrixMath::Inv(MassMatrix);
- temp_product = Jacobian*InverseMassMatrix*JacobianT;
- Lambda = MatrixMath::Inv(temp_product);
-
- // Pull elements of Lambda matrix
- float L11 = Lambda.getNumber(1,1);
- float L12 = Lambda.getNumber(1,2);
- float L21 = Lambda.getNumber(2,1);
- float L22 = Lambda.getNumber(2,2);
-
- // Calculate desired motor torque
- float t1_op = (Jx_th1*L11+Jy_th1*L21)*fx + (Jx_th1*L12+Jy_th1*L22)*fy;
- float t2_op = (Jx_th2*L11+Jy_th2*L21)*fx + (Jx_th2*L12+Jy_th2*L22)*fy;
+ float T1 = Jx_th1*fx+Jy_th1*fy;
+ float T2 = Jx_th2*fx+Jy_th2*fy;
+
// Set desired currents
- current_des1 = t1_op/k_t;
- current_des2 = t2_op/k_t;
-
+
+ // Joint impedance
+ // sub Kxx for K1, Dxx for D1, Kyy for K2, Dyy for D2
+ // Note: Be careful with signs now that you have non-zero desired angles!
+ // Your equations should be of the form i_d = K1*(q1_d - q1) + D1*(dq1_d - dq1)
+// current_des1 = (K_xx*(th1_des-angle1) + D_xx*(dth1_des-velocity1))/k_t;
+// current_des2 = (K_yy*(th2_des-angle2) + D_yy*(dth2_des-velocity2))/k_t;
+
+ // Cartesian impedance
+ // Note: As with the joint space laws, be careful with signs!
+ current_des1 = T1/k_t;
+ current_des2 = T2/k_t;
+
+
// Form output to send to MATLAB
float output_data[NUM_OUTPUTS];
// current time
@@ -380,6 +344,9 @@
currentLoop.detach();
motorShield.motorAWrite(0, 0); //turn motor A off
motorShield.motorBWrite(0, 0); //turn motor B off
+
} // end if
+
} // end while
+
} // end main
\ No newline at end of file
