Diff: help_functions/kinematics.h

Revision:

13:3482d315877c

Parent:

6:8ff9566c91e2

--- a/help_functions/kinematics.h	Tue Oct 23 08:44:17 2018 +0000
+++ b/help_functions/kinematics.h	Mon Oct 29 12:55:38 2018 +0000
@@ -1,20 +1,31 @@
-#include "mbed.h"
-
+ 
 double L1 = 0.5;
 double L2 = 0.7;
 double x01 = 0.0;
 double y01 = 0.2;
-
-void forwardkinematics_function(double q1, double q2) {
+ 
+void forwardkinematics_function(double& q1, double& q2) {
     // input are joint angles, output are x and y position of end effector
     
-    x = x01 - L1 * sin(q1) + L2 * cos(q1 + q2);
-    y = y01 + L1 * cos(q1) + L2 * sin(q1 + q2);    
+    currentx = x01 + L1*cos(q1)-L2*cos(q2);
+    currenty = y01 + L1 * sin(q1) - L2 * sin(q2);    
 }
-
-double inversekinematics_function(double q1, double q2, double reference) {
+ 
+double inversekinematics_function(double& x, double& y, const double& T, double& qref1, double& qref2, double& q1, double& q2, double& des_vx, double& des_vy) {
+    // x, y: positions of end effector | T: period | qref1, qref2: reference thetas | q1, q2: current thetas | vx, vy: desired x, y velocities
+    
     // pseudo inverse jacobian to get joint speeds
     // input are desired vx and vy of end effector, output joint angle speeds
+ 
+    double q1_star_des; // desired joint velocity of q1_star
+    double q2_star_des; // same as above but then for q2_star
+ 
+    // The calculation below assumes that the end effector position is calculated before this function is executed
+    // In our case the determinant will not equal zero, hence no problems with singularies I think.
+    q1_star_des = 1/(L1*(-x*sin(q1)-(-y+y01)*cos(q1)))*(-1*(-x+L1*cos(q1))*des_vx-x*des_vy);
+    q2_star_des = 1/(L1*(-x*sin(q1)-(-y+y01)*cos(q1)))*(-1*(-y+y01+L1*sin(q1))*des_vx+1*(-y+y01))*des_vy);
     
-    return 5.5;    
+    qref1 = q1+T*q1_star_des; // Yet to adapt all these equations
+    qref2 = q2+T*(q2_star_des - q1_star_des);    
+    
 }
\ No newline at end of file