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MarlinFirmware/Marlin/src/module/delta.cpp
2019-09-29 04:25:39 -05:00

266 lines
9.1 KiB
C++

/**
* Marlin 3D Printer Firmware
* Copyright (c) 2019 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
*
* Based on Sprinter and grbl.
* Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
/**
* delta.cpp
*/
#include "../inc/MarlinConfig.h"
#if ENABLED(DELTA)
#include "delta.h"
#include "motion.h"
// For homing:
#include "planner.h"
#include "endstops.h"
#include "../lcd/ultralcd.h"
#include "../Marlin.h"
#if HAS_BED_PROBE
#include "probe.h"
#endif
#if ENABLED(SENSORLESS_HOMING)
#include "../feature/tmc_util.h"
#include "stepper/indirection.h"
#endif
#define DEBUG_OUT ENABLED(DEBUG_LEVELING_FEATURE)
#include "../core/debug_out.h"
// Initialized by settings.load()
float delta_height;
abc_float_t delta_endstop_adj{0};
float delta_radius,
delta_diagonal_rod,
delta_segments_per_second,
delta_calibration_radius;
abc_float_t delta_tower_angle_trim;
xy_float_t delta_tower[ABC];
abc_float_t delta_diagonal_rod_2_tower;
float delta_clip_start_height = Z_MAX_POS;
float delta_safe_distance_from_top();
/**
* Recalculate factors used for delta kinematics whenever
* settings have been changed (e.g., by M665).
*/
void recalc_delta_settings() {
constexpr abc_float_t trt = DELTA_RADIUS_TRIM_TOWER,
drt = DELTA_DIAGONAL_ROD_TRIM_TOWER;
delta_tower[A_AXIS].set(cos(RADIANS(210 + delta_tower_angle_trim.a)) * (delta_radius + trt.a), // front left tower
sin(RADIANS(210 + delta_tower_angle_trim.a)) * (delta_radius + trt.a));
delta_tower[B_AXIS].set(cos(RADIANS(330 + delta_tower_angle_trim.b)) * (delta_radius + trt.b), // front right tower
sin(RADIANS(330 + delta_tower_angle_trim.b)) * (delta_radius + trt.b));
delta_tower[C_AXIS].set(cos(RADIANS( 90 + delta_tower_angle_trim.c)) * (delta_radius + trt.c), // back middle tower
sin(RADIANS( 90 + delta_tower_angle_trim.c)) * (delta_radius + trt.c));
delta_diagonal_rod_2_tower.set(sq(delta_diagonal_rod + drt.a),
sq(delta_diagonal_rod + drt.b),
sq(delta_diagonal_rod + drt.c));
update_software_endstops(Z_AXIS);
set_all_unhomed();
}
/**
* Delta Inverse Kinematics
*
* Calculate the tower positions for a given machine
* position, storing the result in the delta[] array.
*
* This is an expensive calculation, requiring 3 square
* roots per segmented linear move, and strains the limits
* of a Mega2560 with a Graphical Display.
*
* Suggested optimizations include:
*
* - Disable the home_offset (M206) and/or position_shift (G92)
* features to remove up to 12 float additions.
*/
#define DELTA_DEBUG(VAR) do { \
SERIAL_ECHOLNPAIR("Cartesian X", VAR.x, " Y", VAR.y, " Z", VAR.z); \
SERIAL_ECHOLNPAIR("Delta A", delta.a, " B", delta.b, " C", delta.c); \
}while(0)
void inverse_kinematics(const xyz_pos_t &raw) {
#if HAS_HOTEND_OFFSET
// Delta hotend offsets must be applied in Cartesian space with no "spoofing"
xyz_pos_t pos = { raw.x - hotend_offset[active_extruder].x,
raw.y - hotend_offset[active_extruder].y,
raw.z };
DELTA_IK(pos);
//DELTA_DEBUG(pos);
#else
DELTA_IK(raw);
//DELTA_DEBUG(raw);
#endif
}
/**
* Calculate the highest Z position where the
* effector has the full range of XY motion.
*/
float delta_safe_distance_from_top() {
xyz_pos_t cartesian{0};
inverse_kinematics(cartesian);
const float centered_extent = delta.a;
cartesian.y = DELTA_PRINTABLE_RADIUS;
inverse_kinematics(cartesian);
return ABS(centered_extent - delta.a);
}
/**
* Delta Forward Kinematics
*
* See the Wikipedia article "Trilateration"
* https://en.wikipedia.org/wiki/Trilateration
*
* Establish a new coordinate system in the plane of the
* three carriage points. This system has its origin at
* tower1, with tower2 on the X axis. Tower3 is in the X-Y
* plane with a Z component of zero.
* We will define unit vectors in this coordinate system
* in our original coordinate system. Then when we calculate
* the Xnew, Ynew and Znew values, we can translate back into
* the original system by moving along those unit vectors
* by the corresponding values.
*
* Variable names matched to Marlin, c-version, and avoid the
* use of any vector library.
*
* by Andreas Hardtung 2016-06-07
* based on a Java function from "Delta Robot Kinematics V3"
* by Steve Graves
*
* The result is stored in the cartes[] array.
*/
void forward_kinematics_DELTA(const float &z1, const float &z2, const float &z3) {
// Create a vector in old coordinates along x axis of new coordinate
const float p12[3] = { delta_tower[B_AXIS].x - delta_tower[A_AXIS].x, delta_tower[B_AXIS].y - delta_tower[A_AXIS].y, z2 - z1 },
// Get the reciprocal of Magnitude of vector.
d2 = sq(p12[0]) + sq(p12[1]) + sq(p12[2]), inv_d = RSQRT(d2),
// Create unit vector by multiplying by the inverse of the magnitude.
ex[3] = { p12[0] * inv_d, p12[1] * inv_d, p12[2] * inv_d },
// Get the vector from the origin of the new system to the third point.
p13[3] = { delta_tower[C_AXIS].x - delta_tower[A_AXIS].x, delta_tower[C_AXIS].y - delta_tower[A_AXIS].y, z3 - z1 },
// Use the dot product to find the component of this vector on the X axis.
i = ex[0] * p13[0] + ex[1] * p13[1] + ex[2] * p13[2],
// Create a vector along the x axis that represents the x component of p13.
iex[3] = { ex[0] * i, ex[1] * i, ex[2] * i };
// Subtract the X component from the original vector leaving only Y. We use the
// variable that will be the unit vector after we scale it.
float ey[3] = { p13[0] - iex[0], p13[1] - iex[1], p13[2] - iex[2] };
// The magnitude and the inverse of the magnitude of Y component
const float j2 = sq(ey[0]) + sq(ey[1]) + sq(ey[2]), inv_j = RSQRT(j2);
// Convert to a unit vector
ey[0] *= inv_j; ey[1] *= inv_j; ey[2] *= inv_j;
// The cross product of the unit x and y is the unit z
// float[] ez = vectorCrossProd(ex, ey);
const float ez[3] = {
ex[1] * ey[2] - ex[2] * ey[1],
ex[2] * ey[0] - ex[0] * ey[2],
ex[0] * ey[1] - ex[1] * ey[0]
},
// We now have the d, i and j values defined in Wikipedia.
// Plug them into the equations defined in Wikipedia for Xnew, Ynew and Znew
Xnew = (delta_diagonal_rod_2_tower.a - delta_diagonal_rod_2_tower.b + d2) * inv_d * 0.5,
Ynew = ((delta_diagonal_rod_2_tower.a - delta_diagonal_rod_2_tower.c + sq(i) + j2) * 0.5 - i * Xnew) * inv_j,
Znew = SQRT(delta_diagonal_rod_2_tower.a - HYPOT2(Xnew, Ynew));
// Start from the origin of the old coordinates and add vectors in the
// old coords that represent the Xnew, Ynew and Znew to find the point
// in the old system.
cartes.set(delta_tower[A_AXIS].x + ex[0] * Xnew + ey[0] * Ynew - ez[0] * Znew,
delta_tower[A_AXIS].y + ex[1] * Xnew + ey[1] * Ynew - ez[1] * Znew,
z1 + ex[2] * Xnew + ey[2] * Ynew - ez[2] * Znew);
}
/**
* A delta can only safely home all axes at the same time
* This is like quick_home_xy() but for 3 towers.
*/
void home_delta() {
if (DEBUGGING(LEVELING)) DEBUG_POS(">>> home_delta", current_position);
// Init the current position of all carriages to 0,0,0
current_position.reset();
destination.reset();
sync_plan_position();
// Disable stealthChop if used. Enable diag1 pin on driver.
#if ENABLED(SENSORLESS_HOMING)
sensorless_t stealth_states {
tmc_enable_stallguard(stepperX),
tmc_enable_stallguard(stepperY),
tmc_enable_stallguard(stepperZ)
};
#endif
// Move all carriages together linearly until an endstop is hit.
current_position.z = (delta_height + 10
#if HAS_BED_PROBE
- probe_offset.z
#endif
);
line_to_current_position(homing_feedrate(X_AXIS));
planner.synchronize();
// Re-enable stealthChop if used. Disable diag1 pin on driver.
#if ENABLED(SENSORLESS_HOMING)
tmc_disable_stallguard(stepperX, stealth_states.x);
tmc_disable_stallguard(stepperY, stealth_states.y);
tmc_disable_stallguard(stepperZ, stealth_states.z);
#endif
endstops.validate_homing_move();
// At least one carriage has reached the top.
// Now re-home each carriage separately.
homeaxis(A_AXIS);
homeaxis(B_AXIS);
homeaxis(C_AXIS);
// Set all carriages to their home positions
// Do this here all at once for Delta, because
// XYZ isn't ABC. Applying this per-tower would
// give the impression that they are the same.
LOOP_XYZ(i) set_axis_is_at_home((AxisEnum)i);
sync_plan_position();
if (DEBUGGING(LEVELING)) DEBUG_POS("<<< home_delta", current_position);
}
#endif // DELTA