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MarlinFirmware/Marlin/src/module/delta.cpp
2017-11-04 00:05:38 -05:00

266 lines
9.5 KiB
C++

/**
* Marlin 3D Printer Firmware
* Copyright (C) 2016 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 "stepper.h"
#include "endstops.h"
#include "../lcd/ultralcd.h"
#include "../Marlin.h"
// Initialized by settings.load()
float delta_endstop_adj[ABC] = { 0 },
delta_radius,
delta_diagonal_rod,
delta_segments_per_second,
delta_calibration_radius,
delta_tower_angle_trim[ABC];
float delta_tower[ABC][2],
delta_diagonal_rod_2_tower[ABC],
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(const float radius, const float diagonal_rod, const float tower_angle_trim[ABC]) {
const float trt[ABC] = DELTA_RADIUS_TRIM_TOWER,
drt[ABC] = DELTA_DIAGONAL_ROD_TRIM_TOWER;
delta_tower[A_AXIS][X_AXIS] = cos(RADIANS(210 + tower_angle_trim[A_AXIS])) * (radius + trt[A_AXIS]); // front left tower
delta_tower[A_AXIS][Y_AXIS] = sin(RADIANS(210 + tower_angle_trim[A_AXIS])) * (radius + trt[A_AXIS]);
delta_tower[B_AXIS][X_AXIS] = cos(RADIANS(330 + tower_angle_trim[B_AXIS])) * (radius + trt[B_AXIS]); // front right tower
delta_tower[B_AXIS][Y_AXIS] = sin(RADIANS(330 + tower_angle_trim[B_AXIS])) * (radius + trt[B_AXIS]);
delta_tower[C_AXIS][X_AXIS] = cos(RADIANS( 90 + tower_angle_trim[C_AXIS])) * (radius + trt[C_AXIS]); // back middle tower
delta_tower[C_AXIS][Y_AXIS] = sin(RADIANS( 90 + tower_angle_trim[C_AXIS])) * (radius + trt[C_AXIS]);
delta_diagonal_rod_2_tower[A_AXIS] = sq(diagonal_rod + drt[A_AXIS]);
delta_diagonal_rod_2_tower[B_AXIS] = sq(diagonal_rod + drt[B_AXIS]);
delta_diagonal_rod_2_tower[C_AXIS] = sq(diagonal_rod + drt[C_AXIS]);
}
/**
* 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.
*
* - Use a fast-inverse-sqrt function and add the reciprocal.
* (see above)
*/
#if ENABLED(DELTA_FAST_SQRT) && defined(__AVR__)
/**
* Fast inverse sqrt from Quake III Arena
* See: https://en.wikipedia.org/wiki/Fast_inverse_square_root
*/
float Q_rsqrt(float number) {
long i;
float x2, y;
const float threehalfs = 1.5f;
x2 = number * 0.5f;
y = number;
i = * ( long * ) &y; // evil floating point bit level hacking
i = 0x5F3759DF - ( i >> 1 ); // what the f***?
y = * ( float * ) &i;
y = y * ( threehalfs - ( x2 * y * y ) ); // 1st iteration
// y = y * ( threehalfs - ( x2 * y * y ) ); // 2nd iteration, this can be removed
return y;
}
#endif
#define DELTA_DEBUG() do { \
SERIAL_ECHOPAIR("cartesian X:", raw[X_AXIS]); \
SERIAL_ECHOPAIR(" Y:", raw[Y_AXIS]); \
SERIAL_ECHOLNPAIR(" Z:", raw[Z_AXIS]); \
SERIAL_ECHOPAIR("delta A:", delta[A_AXIS]); \
SERIAL_ECHOPAIR(" B:", delta[B_AXIS]); \
SERIAL_ECHOLNPAIR(" C:", delta[C_AXIS]); \
}while(0)
void inverse_kinematics(const float raw[XYZ]) {
DELTA_RAW_IK();
// DELTA_DEBUG();
}
/**
* Calculate the highest Z position where the
* effector has the full range of XY motion.
*/
float delta_safe_distance_from_top() {
float cartesian[XYZ] = { 0, 0, 0 };
inverse_kinematics(cartesian);
float distance = delta[A_AXIS];
cartesian[Y_AXIS] = DELTA_PRINTABLE_RADIUS;
inverse_kinematics(cartesian);
return FABS(distance - delta[A_AXIS]);
}
/**
* 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(float z1, float z2, float z3) {
// Create a vector in old coordinates along x axis of new coordinate
float p12[3] = { delta_tower[B_AXIS][X_AXIS] - delta_tower[A_AXIS][X_AXIS], delta_tower[B_AXIS][Y_AXIS] - delta_tower[A_AXIS][Y_AXIS], z2 - z1 };
// Get the Magnitude of vector.
float d = SQRT( sq(p12[0]) + sq(p12[1]) + sq(p12[2]) );
// Create unit vector by dividing by magnitude.
float ex[3] = { p12[0] / d, p12[1] / d, p12[2] / d };
// Get the vector from the origin of the new system to the third point.
float p13[3] = { delta_tower[C_AXIS][X_AXIS] - delta_tower[A_AXIS][X_AXIS], delta_tower[C_AXIS][Y_AXIS] - delta_tower[A_AXIS][Y_AXIS], z3 - z1 };
// Use the dot product to find the component of this vector on the X axis.
float 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.
float 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 of Y component
float j = SQRT( sq(ey[0]) + sq(ey[1]) + sq(ey[2]) );
// Convert to a unit vector
ey[0] /= j; ey[1] /= j; ey[2] /= j;
// The cross product of the unit x and y is the unit z
// float[] ez = vectorCrossProd(ex, ey);
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
float Xnew = (delta_diagonal_rod_2_tower[A_AXIS] - delta_diagonal_rod_2_tower[B_AXIS] + sq(d)) / (d * 2),
Ynew = ((delta_diagonal_rod_2_tower[A_AXIS] - delta_diagonal_rod_2_tower[C_AXIS] + HYPOT2(i, j)) / 2 - i * Xnew) / j,
Znew = SQRT(delta_diagonal_rod_2_tower[A_AXIS] - 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[X_AXIS] = delta_tower[A_AXIS][X_AXIS] + ex[0] * Xnew + ey[0] * Ynew - ez[0] * Znew;
cartes[Y_AXIS] = delta_tower[A_AXIS][Y_AXIS] + ex[1] * Xnew + ey[1] * Ynew - ez[1] * Znew;
cartes[Z_AXIS] = 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.
*/
bool home_delta() {
#if ENABLED(DEBUG_LEVELING_FEATURE)
if (DEBUGGING(LEVELING)) DEBUG_POS(">>> home_delta", current_position);
#endif
// Init the current position of all carriages to 0,0,0
ZERO(current_position);
sync_plan_position();
// Move all carriages together linearly until an endstop is hit.
current_position[X_AXIS] = current_position[Y_AXIS] = current_position[Z_AXIS] = (DELTA_HEIGHT + home_offset[Z_AXIS] + 10);
feedrate_mm_s = homing_feedrate(X_AXIS);
line_to_current_position();
stepper.synchronize();
// If an endstop was not hit, then damage can occur if homing is continued.
// This can occur if the delta height (DELTA_HEIGHT + home_offset[Z_AXIS]) is
// not set correctly.
if (!(Endstops::endstop_hit_bits & (_BV(X_MAX) | _BV(Y_MAX) | _BV(Z_MAX)))) {
LCD_MESSAGEPGM(MSG_ERR_HOMING_FAILED);
SERIAL_ERROR_START();
SERIAL_ERRORLNPGM(MSG_ERR_HOMING_FAILED);
return false;
}
endstops.hit_on_purpose(); // clear endstop hit flags
// At least one carriage has reached the top.
// Now re-home each carriage separately.
HOMEAXIS(A);
HOMEAXIS(B);
HOMEAXIS(C);
// 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_KINEMATIC();
#if ENABLED(DEBUG_LEVELING_FEATURE)
if (DEBUGGING(LEVELING)) DEBUG_POS("<<< home_delta", current_position);
#endif
return true;
}
#endif // DELTA