Biorobotics / Mbed 2 deprecated frdm_kinematics

Direct and inverse kinematics of a scara robotic arm, based on trigonometry

Dependencies:   MODSERIAL mbed

main.cpp@1:dd8fca950fed, 2015-10-19 (annotated)

Committer:
apdijkshoorn
Date:
Mon Oct 19 12:40:29 2015 +0000
Revision:
1:dd8fca950fed
Parent:
0:8d4438eabc82
Child:
2:47913550ec8d
Working inverse kinematics, singularity for 0

Who changed what in which revision?

UserRevisionLine numberNew contents of line
apdijkshoorn 0:8d4438eabc82 1 #include "mbed.h"
apdijkshoorn 0:8d4438eabc82 2 #include "MODSERIAL.h"
apdijkshoorn 0:8d4438eabc82 3 #define PI 3.14159265
apdijkshoorn 0:8d4438eabc82 4
apdijkshoorn 0:8d4438eabc82 5 MODSERIAL pc(USBTX, USBRX);
apdijkshoorn 0:8d4438eabc82 6
apdijkshoorn 0:8d4438eabc82 7 void DirectKin(double& a, double& b, double theta1, double theta2)
apdijkshoorn 0:8d4438eabc82 8 {
apdijkshoorn 0:8d4438eabc82 9 double L1 = 0.34;
apdijkshoorn 0:8d4438eabc82 10 double L2 = 0.26;
apdijkshoorn 0:8d4438eabc82 11 double theta1_0 = 0;
apdijkshoorn 0:8d4438eabc82 12 double theta2_0 = 0;
apdijkshoorn 0:8d4438eabc82 13
apdijkshoorn 0:8d4438eabc82 14 double r0_1[2] = {L1*cos((theta1_0+theta1) * PI / 180.0) , L1*sin((theta1_0+theta1) * PI / 180.0)};
apdijkshoorn 0:8d4438eabc82 15 double r0_2[2] = {L1*cos((theta1_0+theta1) * PI / 180.0)+L2*cos((theta1_0+theta1+theta2+theta2_0)* PI / 180.0), L1*sin((theta1_0+theta1) * PI / 180.0)+L2*sin((theta1_0+theta1+theta2+theta2_0)* PI / 180.0)};
apdijkshoorn 0:8d4438eabc82 16
apdijkshoorn 0:8d4438eabc82 17 double x = r0_2[0];
apdijkshoorn 0:8d4438eabc82 18 double y = r0_2[1];
apdijkshoorn 0:8d4438eabc82 19
apdijkshoorn 0:8d4438eabc82 20 a = x;
apdijkshoorn 0:8d4438eabc82 21 b = y;
apdijkshoorn 0:8d4438eabc82 22 }
apdijkshoorn 0:8d4438eabc82 23
apdijkshoorn 0:8d4438eabc82 24 void IndirectKin(double&a, double& b, double x, double y)
apdijkshoorn 0:8d4438eabc82 25 {
apdijkshoorn 0:8d4438eabc82 26 double L1 = 0.34;
apdijkshoorn 0:8d4438eabc82 27 double L2 = 0.26;
apdijkshoorn 0:8d4438eabc82 28 double para2 = (x*x+y*y-L1*L1-L2*L2)/(2*L1*L2);
apdijkshoorn 0:8d4438eabc82 29
apdijkshoorn 1:dd8fca950fed 30 double theta_2 = acos(para2)* 180 / PI;
apdijkshoorn 0:8d4438eabc82 31 double theta_total = atan2 (y,x) * 180 / PI;
apdijkshoorn 1:dd8fca950fed 32 double theta_Q = acos( (x*x+y*y+L1*L1-L2*L2) / (2*L1*sqrt(x*x+y*y)) )* 180 / PI;
apdijkshoorn 0:8d4438eabc82 33 double theta_1 = theta_total - theta_Q;
apdijkshoorn 0:8d4438eabc82 34
apdijkshoorn 0:8d4438eabc82 35 a = theta_1;
apdijkshoorn 0:8d4438eabc82 36 b = theta_2;
apdijkshoorn 0:8d4438eabc82 37 }
apdijkshoorn 0:8d4438eabc82 38
apdijkshoorn 0:8d4438eabc82 39
apdijkshoorn 0:8d4438eabc82 40 int main()
apdijkshoorn 0:8d4438eabc82 41 {
apdijkshoorn 0:8d4438eabc82 42 pc.baud(115200);
apdijkshoorn 0:8d4438eabc82 43
apdijkshoorn 1:dd8fca950fed 44 double theta_1 = 1.0;
apdijkshoorn 1:dd8fca950fed 45 double theta_2 = 1.0;
apdijkshoorn 0:8d4438eabc82 46
apdijkshoorn 0:8d4438eabc82 47 double xy[2] = {0.0,0.0};
apdijkshoorn 0:8d4438eabc82 48
apdijkshoorn 0:8d4438eabc82 49
apdijkshoorn 0:8d4438eabc82 50
apdijkshoorn 0:8d4438eabc82 51 while (true) {
apdijkshoorn 0:8d4438eabc82 52 wait(0.5f);
apdijkshoorn 0:8d4438eabc82 53 DirectKin(xy[0],xy[1], theta_1, theta_2);
apdijkshoorn 0:8d4438eabc82 54 // pc.printf("%4.4f %4.4f \n",xy[0], xy[1]);
apdijkshoorn 0:8d4438eabc82 55
apdijkshoorn 0:8d4438eabc82 56 IndirectKin(theta_1, theta_2, xy[0], xy[1]);
apdijkshoorn 0:8d4438eabc82 57 pc.printf("%4.4f %4.4f \n",theta_1, theta_2);
apdijkshoorn 0:8d4438eabc82 58
apdijkshoorn 0:8d4438eabc82 59 theta_1 = theta_1 + 90.0;
apdijkshoorn 0:8d4438eabc82 60 }
apdijkshoorn 0:8d4438eabc82 61 }