State machine
Dependencies: mbed Adafruit_GFX BioroboticsMotorControl MODSERIAL BioroboticsEMGFilter
Diff: inverse_kinematics.h
- Revision:
- 21:d541303a2ea6
- Child:
- 26:a8f4a117cc0d
diff -r af1a6cd7469b -r d541303a2ea6 inverse_kinematics.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/inverse_kinematics.h Wed Oct 31 18:54:07 2018 +0000 @@ -0,0 +1,75 @@ +#pragma once + +#include "mbed.h" +#include "constants.h" + + +// Pass the two values that you want the target angle outputs in, as 3rd and 4th arguments. +void inverse_kinematics(double Pe_x, double Pe_y, double &dest_main_angle, double &dest_sec_angle) +{ + // Calculation of the position of joint 3 in frame 0 + float n = sqrt(pow((L6-Pe_x),2) + pow(Pe_y,2)); // Radius between motor 1 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 = acos( -(pow(L5,2) - pow(n,2) - pow(L4,2))/(2*n*L4) ); // Angle between n and L4 + float lambda = PI - atan(Pe_y/(L6-Pe_x)); // Entire angle between L0 and n + dest_main_angle = lambda - theta; + float J3x_0 = L6 + L4*cos(dest_main_angle); // x-coordinate of joint 3 in frame 0 + float J3y_0 = L4*sin(dest_main_angle); // 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 - L6; // 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! + dest_sec_angle = gamma - beta; + + + // Determining angle delta for safety + float J1x_0 = L0 + L6 + L1*cos(dest_sec_angle); // x-coordinate of joint 1 in frame 0 + float J1y_0 = L1*sin(dest_sec_angle); // y-coordinate of joint 1 in frame 0 + + float m = sqrt(pow((J1x_0 - J3x_0),2) + pow((J3y_0 - J1y_0),2)); // Radius between Joint 1 and Joint 3 + float delta = acos(- (pow(m,2) - pow(L2,2) - pow(L3,2))/(2*L2*L3)); // Angle between L2 and L3 + + + // Implementing stops for safety + // 45 < Motor_angle1 < 70 graden + if (dest_main_angle < main_arm_min_angle) // If motor_angle is smaller than 45 degrees + { + dest_main_angle = main_arm_min_angle; + } + else if (dest_main_angle > main_arm_max_angle) // If motor_angle is larger than 70 degrees + { + dest_main_angle = main_arm_max_angle; + } + + // -42 < Motor_angle2 < 85 graden + if (dest_sec_angle < sec_arm_min_angle) // If motor_angle is smaller than -42 degrees + { + dest_sec_angle = sec_arm_min_angle; + } + else if (dest_sec_angle > sec_arm_max_angle) // If motor_angle is larger than 85 degrees + { + dest_sec_angle = sec_arm_max_angle; + } + + + // Delta < 170 graden + if (delta > 2.96706) // If delta is larger than 180 degrees + { + delta = 2.96706; + } +} \ No newline at end of file