Biorobotics 7
/
Inverse_kinematic
Inverse kinematics
Diff: main.cpp
- Revision:
- 0:4a9c733c3b53
- Child:
- 1:df3d7f71db4b
diff -r 000000000000 -r 4a9c733c3b53 main.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Mon Oct 22 14:52:06 2018 +0000 @@ -0,0 +1,63 @@ +#include "mbed.h" +#include "math.h" +#include "Matrix.h" + +const float L0; // Length between two motors [meter] +const float L1; // Length first beam from right motor2 [meter] +const float L2; // Length second beam from right motor2 [meter] +const float L3; // Length beam between L2 and L4 [meter] +const float L4; // Length first beam from left motor1 [meter] +const float L5; // Length from L3 to end-effector [meter] +const double PI = 3.14159265359; +volatile float Pe_x; // x-coordinate of end-effector from frame 0 [meter] +volatile float Pe_y; // y-coordinate of end-effector from frame 0 [meter] +volatile float motor_angle1; // Desired angle of motor 1 (left) [rad] +volatile float motor_angle2; // Desired angle of motor 2 (right) [rad] + +ticker IK // Ticker function for inverse kinematics + +void InverseKinematics() +{ + // Calculation of the position of joint 3 in frame 0 + float n = sqrt(pow(Pe_x,2) + pow(Pe_y,2); // Radius between origin frame 0 and endeffector [meter] + float omega = acos(-(pow(n,2) - pow(L4,2) - pow(L5,2))/(2*L4*L5)); // Angle between L4 and L5 [rad] + float q4 = PI - omega; // Angle of joint 3 between L3 and L4 + float theta = atan(L5*sin(q4)/(L4 + L5*cos(q4)); // Angle between n and L4 + float lambda = PI - atan(abs(Pe_y/Pe_x)); // Entire angle between x-axis frame 0 and n + float motor_angle1 = lambda - theta; + float J3x_0 = L4*cos(q3); // x-coordinate of joint 3 in frame 0 + float J3y_0 = L4*sin(q3); // y-coordinate of joint 3 in frame 0 + + // Calculation of the position of joint 2 in frame 0 + float S = abs(J3y_0 - Pe_y); // Distance between height endeffector and joint 3 + float kappa = asin(S/L5); // Angle of L5 + float J2x_0 = (L3+L5)*cos(kappa) + Pe_x; // x-coordinate of joint 2 in frame 0 + float J2y_0 = (L3+L5)*sin(kappa) + Pe_y; // y-coordinate of joint 2 in frame 0 + + // Calculation of the position of joint 1 in frame 0 + float J2x_1 = J2x_0 - L0; // x-coordinate of joint 2 in frame 1 + float J2y_1 = J2y_0; // y-coordinate of joint 2 in frame 1 + float r = sqrt(pow(J2x_1,2) + pow(J2y_1,2); // Radius between origin frame 1 and J2 + float alfa = acos(-(pow(r,2) - pow(L1,2) - pow(L2,2))/(2*L1*L2 // Angle opposite of radius r + float q2 = PI - alfa; // Angle between L1 and L2 + + // Calculation of motor_angle2 + float beta = atan(L2*sin(q2)/(L1+L2*cos(q2))); // Angle between r and L1 + float gamma = PI - atan(abs(J2y_1/J2x_1); // Angle between r and x-axis + // check if gamma works! + m_anle2 = gamma - beta; + float J1x_0 = L0 + L1*cos(q1); // x-coordinate of joint 1 in frame 0 + float J1y_0 = L1*sin(q1); // y-coordinate of joint 1 in frame 0 + + + + + return motor_angle1 + return motor_angle2 +} + + +int main() +{ + IK.attach(InverseKinematics) +} \ No newline at end of file