Library for analyitical inverse kinematics on 4-legged 3DOF per leg quadrupod robots. Easily modifyable for more legs.
Dependents: Quadrapod NeoQuadrapod
ArthropodIK.cpp
- Committer:
- ikrase
- Date:
- 2015-06-25
- Revision:
- 0:9805c9d36254
- Child:
- 1:031a0c78d8d6
File content as of revision 0:9805c9d36254:
#include "mbed.h" #include "quadrapod_defs.h" #include "ArthropodIK.h" float sq(float n1){ float res = n1 * n1; return res; } const float ArthropodSolver::LEG_ANGLES[4] = {0.78539816339, 2.35619449019, -2.35619449019, -0.78539816339, }; ArthropodSolver::ArthropodSolver() // Constuctor initializes thing. { } leg_angles_t ArthropodSolver::SolveLeg(float LegTargetXYZ[], int LegNum) { leg_angles_t angles_out; angles_out.gamma = atan2(LegTargetXYZ[1], LegTargetXYZ[0]) - LEG_ANGLES[LegNum]; float lp = sqrt(sq(LegTargetXYZ[0]) + sq(LegTargetXYZ[1])); float L2 = sq(LegTargetXYZ[2]) + sq(lp - COXA_L); float a1 = acos(-LegTargetXYZ[2] / sqrt(L2)); float a2 = acos((sq(TIBIA_L)-sq(FEMUR_L)-L2)/(-2*FEMUR_L*sqrt(L2))); angles_out.alpha = a1 + a2; angles_out.beta = acos((-sq(TIBIA_L)-sq(FEMUR_L)+L2)/(-2*FEMUR_L*TIBIA_L)); // IK code, the most basic section. return angles_out; // THIS WILL OVERWRITE WITH MULTIPLE CALLS!!!!!! } float * ArthropodSolver::SolveBody(sixDOF_t BodyTarget6D[], float LegPriorPos[], int LegNum) { static float foot_pos_out[NUM_LEGS]; // IK code // Loop calls SolveLeg() return foot_pos_out; } float * ArthropodSolver::SolveLegFwd(leg_angles_t LegAngles, int LegNum){ static float footpos_out[3]; //x y z // code float L; float b1; b1 = LegAngles.beta - (PI - LegAngles.alpha); // The part of beta that matters. L = sin(b1) * TIBIA_L + COXA_L + sin(LegAngles.alpha) * FEMUR_L; // the extension length. footpos_out[0] = L * cos(LEG_ANGLES[LegNum] + LegAngles.gamma); footpos_out[1] = L * sin(LEG_ANGLES[LegNum] + LegAngles.gamma); footpos_out[2] = -cos(LegAngles.alpha) - TIBIA_L*cos(b1) ; return footpos_out; } void ArthropodSolver::YawXform(float invec[], float outvec[], float angle) { outvec[0] = invec[0]*cos(angle)- invec[1]*sin(angle); outvec[1] = invec[0] * sin(angle) + outvec[1] * cos(angle); outvec[2] = invec[2]; } void ArthropodSolver::PitchXform(float invec[], float outvec[], float angle){ outvec[1] = invec[1]*cos(angle)- invec[2]*sin(angle); outvec[2] = invec[1] * sin(angle) + outvec[2] * cos(angle); outvec[0] = invec[0]; } void ArthropodSolver::RollXform(float invec[], float outvec[], float angle){ outvec[2] = invec[2]*cos(angle)- invec[0]*sin(angle); outvec[0] = invec[0] * cos(angle) + outvec[2] * sin(angle); outvec[1] = invec[1]; }