From c4fcf8bfd70fea25d28fb8c7025b0f9c2496aaa5 Mon Sep 17 00:00:00 2001 From: Scott Lahteine Date: Wed, 17 Feb 2021 17:04:51 -0600 Subject: [PATCH] Fixes for MP_SCARA (#21113) Co-Authored-By: svsergo <52426708+svsergo@users.noreply.github.com> --- Marlin/src/module/scara.cpp | 111 ++++++++++++++++-------------------- 1 file changed, 50 insertions(+), 61 deletions(-) diff --git a/Marlin/src/module/scara.cpp b/Marlin/src/module/scara.cpp index e4b2f0b75c..565a502d5b 100644 --- a/Marlin/src/module/scara.cpp +++ b/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; - // 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); - 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); + LIMIT(C2, -1, 1); - S2 = SQRT(1.0f - sq(C2)); + S2 = SQRT(1.0f - sq(C2)); - // Unrotated Arm1 plus rotated Arm2 gives the distance from Center to End - SK1 = L1 + L2 * C2; + // Unrotated Arm1 plus rotated Arm2 gives the distance from Center to End + SK1 = L1 + L2 * C2; - // Rotated Arm2 gives the distance from Arm1 to Arm2 - SK2 = L2 * S2; + // Rotated Arm2 gives the distance from Arm1 to Arm2 + SK2 = L2 * S2; - // 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); + // 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); - // Angle of Arm2 - PSI = ATAN2(S2, C2); + // Angle of Arm2 + PSI = ATAN2(S2, C2); - delta.set(DEGREES(THETA), DEGREES(THETA + PSI), raw.z); + delta.set(DEGREES(THETA), DEGREES(PSI + TERN0(MORGAN_SCARA, THETA)), raw.z); - /* - 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); - //*/ - - #else // MP_SCARA - - 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(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(); }