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Fixes for MP_SCARA (#21113)

Co-Authored-By: svsergo <52426708+svsergo@users.noreply.github.com>
vanilla_fb_2.0.x
Scott Lahteine 4 years ago
parent
commit
c4fcf8bfd7
  1. 111
      Marlin/src/module/scara.cpp

111
Marlin/src/module/scara.cpp

@ -47,19 +47,22 @@ void scara_set_axis_is_at_home(const AxisEnum axis) {
#if ENABLED(MORGAN_SCARA)
// MORGAN_SCARA uses arm angles for AB home position
// SERIAL_ECHOLNPAIR("homeposition A:", homeposition.a, " B:", homeposition.b);
//DEBUG_ECHOLNPAIR("homeposition A:", homeposition.a, " B:", homeposition.b);
inverse_kinematics(homeposition);
forward_kinematics_SCARA(delta.a, delta.b);
current_position[axis] = cartes[axis];
#else
// MP_SCARA uses a Cartesian XY home position
// SERIAL_ECHOPGM("homeposition");
// SERIAL_ECHOLNPAIR_P(SP_X_LBL, homeposition.x, SP_Y_LBL, homeposition.y);
current_position[axis] = homeposition[axis];
//DEBUG_ECHOPGM("homeposition");
//DEBUG_ECHOLNPAIR_P(SP_X_LBL, homeposition.x, SP_Y_LBL, homeposition.y);
delta.a = SCARA_OFFSET_THETA1;
delta.b = SCARA_OFFSET_THETA2;
forward_kinematics_SCARA(delta.a, delta.b);
current_position[axis] = cartes[axis];
#endif
// SERIAL_ECHOPGM("Cartesian");
// SERIAL_ECHOLNPAIR_P(SP_X_LBL, current_position.x, SP_Y_LBL, current_position.y);
//DEBUG_ECHOPGM("Cartesian");
//DEBUG_ECHOLNPAIR_P(SP_X_LBL, current_position.x, SP_Y_LBL, current_position.y);
update_software_endstops(axis);
}
}
@ -75,14 +78,14 @@ void forward_kinematics_SCARA(const float &a, const float &b) {
const float a_sin = sin(RADIANS(a)) * L1,
a_cos = cos(RADIANS(a)) * L1,
b_sin = sin(RADIANS(b)) * L2,
b_cos = cos(RADIANS(b)) * L2;
b_sin = sin(RADIANS(b + TERN0(MP_SCARA, a))) * L2,
b_cos = cos(RADIANS(b + TERN0(MP_SCARA, a))) * L2;
cartes.set(a_cos + b_cos + scara_offset.x, // theta
a_sin + b_sin + scara_offset.y); // theta+phi
a_sin + b_sin + scara_offset.y); // phi
/*
SERIAL_ECHOLNPAIR(
DEBUG_ECHOLNPAIR(
"SCARA FK Angle a=", a,
" b=", b,
" a_sin=", a_sin,
@ -90,74 +93,60 @@ void forward_kinematics_SCARA(const float &a, const float &b) {
" b_sin=", b_sin,
" b_cos=", b_cos
);
SERIAL_ECHOLNPAIR(" cartes (X,Y) = "(cartes.x, ", ", cartes.y, ")");
DEBUG_ECHOLNPAIR(" cartes (X,Y) = "(cartes.x, ", ", cartes.y, ")");
//*/
}
/**
* SCARA Inverse Kinematics. Results in 'delta'.
*
* See https://reprap.org/forum/read.php?185,283327
*
* Maths and first version by QHARLEY.
* Integrated into Marlin and slightly restructured by Joachim Cerny.
*/
void inverse_kinematics(const xyz_pos_t &raw) {
float C2, S2, SK1, SK2, THETA, PSI;
#if ENABLED(MORGAN_SCARA)
/**
* Morgan SCARA Inverse Kinematics. Results in 'delta'.
*
* See https://reprap.org/forum/read.php?185,283327
*
* Maths and first version by QHARLEY.
* Integrated into Marlin and slightly restructured by Joachim Cerny.
*/
float C2, S2, SK1, SK2, THETA, PSI;
// Translate SCARA to standard XY with scaling factor
const xy_pos_t spos = raw - scara_offset;
const float H2 = HYPOT2(spos.x, spos.y);
if (L1 == L2)
C2 = H2 / L1_2_2 - 1;
else
C2 = (H2 - (L1_2 + L2_2)) / (2.0f * L1 * L2);
S2 = SQRT(1.0f - sq(C2));
// Translate SCARA to standard XY with scaling factor
const xy_pos_t spos = raw - scara_offset;
// Unrotated Arm1 plus rotated Arm2 gives the distance from Center to End
SK1 = L1 + L2 * C2;
const float H2 = HYPOT2(spos.x, spos.y);
if (L1 == L2)
C2 = H2 / L1_2_2 - 1;
else
C2 = (H2 - (L1_2 + L2_2)) / (2.0f * L1 * L2);
// Rotated Arm2 gives the distance from Arm1 to Arm2
SK2 = L2 * S2;
LIMIT(C2, -1, 1);
// Angle of Arm1 is the difference between Center-to-End angle and the Center-to-Elbow
THETA = ATAN2(SK1, SK2) - ATAN2(spos.x, spos.y);
S2 = SQRT(1.0f - sq(C2));
// Angle of Arm2
PSI = ATAN2(S2, C2);
// Unrotated Arm1 plus rotated Arm2 gives the distance from Center to End
SK1 = L1 + L2 * C2;
delta.set(DEGREES(THETA), DEGREES(THETA + PSI), raw.z);
// Rotated Arm2 gives the distance from Arm1 to Arm2
SK2 = L2 * S2;
/*
DEBUG_POS("SCARA IK", raw);
DEBUG_POS("SCARA IK", delta);
SERIAL_ECHOLNPAIR(" SCARA (x,y) ", sx, ",", sy, " C2=", C2, " S2=", S2, " Theta=", THETA, " Phi=", PHI);
//*/
// Angle of Arm1 is the difference between Center-to-End angle and the Center-to-Elbow
THETA = ATAN2(SK1, SK2) - ATAN2(spos.x, spos.y);
#else // MP_SCARA
// Angle of Arm2
PSI = ATAN2(S2, C2);
const float x = raw.x, y = raw.y, c = HYPOT(x, y),
THETA3 = ATAN2(y, x),
THETA1 = THETA3 + ACOS((sq(c) + sq(L1) - sq(L2)) / (2.0f * c * L1)),
THETA2 = THETA3 - ACOS((sq(c) + sq(L2) - sq(L1)) / (2.0f * c * L2));
delta.set(DEGREES(THETA), DEGREES(PSI + TERN0(MORGAN_SCARA, THETA)), raw.z);
delta.set(DEGREES(THETA1), DEGREES(THETA2), raw.z);
/*
DEBUG_POS("SCARA IK", raw);
DEBUG_POS("SCARA IK", delta);
SERIAL_ECHOLNPAIR(" SCARA (x,y) ", x, ",", y," Theta1=", THETA1, " Theta2=", THETA2);
//*/
#endif // MP_SCARA
/*
DEBUG_POS("SCARA IK", raw);
DEBUG_POS("SCARA IK", delta);
DEBUG_ECHOLNPAIR(" SCARA (x,y) ", sx, ",", sy, " C2=", C2, " S2=", S2, " Theta=", THETA, " Psi=", PSI);
//*/
}
void scara_report_positions() {
SERIAL_ECHOLNPAIR("SCARA Theta:", planner.get_axis_position_degrees(A_AXIS), " Psi+Theta:", planner.get_axis_position_degrees(B_AXIS));
SERIAL_ECHOLNPAIR(
"SCARA Theta:", planner.get_axis_position_degrees(A_AXIS),
" Psi" TERN_(MORGAN_SCARA, "+Theta") ":", planner.get_axis_position_degrees(B_AXIS)
);
SERIAL_EOL();
}

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