From ac755fce82a1749ad96c4fe3a61a9ec2dae24814 Mon Sep 17 00:00:00 2001
From: jufimu12 <jufimu12@gmail.com>
Date: Fri, 28 Feb 2020 18:42:51 +0100
Subject: [PATCH] Fix G34 "Decreasing accuracy" bug (#17013)
Co-authored-by: Scott Lahteine <thinkyhead@users.noreply.github.com>
---
Marlin/src/gcode/calibrate/G34_M422.cpp | 72 ++++++++++++++++---------
1 file changed, 47 insertions(+), 25 deletions(-)
diff --git a/Marlin/src/gcode/calibrate/G34_M422.cpp b/Marlin/src/gcode/calibrate/G34_M422.cpp
index 7144038ebd..7923ef9231 100644
--- a/Marlin/src/gcode/calibrate/G34_M422.cpp
+++ b/Marlin/src/gcode/calibrate/G34_M422.cpp
@@ -155,8 +155,12 @@ void GcodeSuite::G34() {
// Move the Z coordinate realm towards the positive - dirty trick
current_position.z -= z_probe * 0.5f;
- float last_z_align_move[NUM_Z_STEPPER_DRIVERS] = ARRAY_N(NUM_Z_STEPPER_DRIVERS, 10000.0f, 10000.0f, 10000.0f),
- z_measured[NUM_Z_STEPPER_DRIVERS] = { 0 },
+ #if DISABLED(Z_STEPPER_ALIGN_KNOWN_STEPPER_POSITIONS)
+ float last_z_align_move[NUM_Z_STEPPER_DRIVERS] = ARRAY_N(NUM_Z_STEPPER_DRIVERS, 10000.0f, 10000.0f, 10000.0f);
+ #else
+ float last_z_align_level_indicator = 10000.0f;
+ #endif
+ float z_measured[NUM_Z_STEPPER_DRIVERS] = { 0 },
z_maxdiff = 0.0f,
amplification = z_auto_align_amplification;
@@ -167,7 +171,7 @@ void GcodeSuite::G34() {
bool adjustment_reverse = false;
#endif
- for (iteration = 0; iteration < z_auto_align_iterations; ++iteration) {
+ LOOP_L_N(iteration, z_auto_align_iterations) {
if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPGM("> probing all positions.");
SERIAL_ECHOLNPAIR("\nITERATION: ", int(iteration + 1));
@@ -177,7 +181,7 @@ void GcodeSuite::G34() {
z_measured_max = -100000.0f;
// Probe all positions (one per Z-Stepper)
- for (uint8_t i = 0; i < NUM_Z_STEPPER_DRIVERS; ++i) {
+ LOOP_L_N(i, NUM_Z_STEPPER_DRIVERS) {
// iteration odd/even --> downward / upward stepper sequence
const uint8_t iprobe = (iteration & 1) ? NUM_Z_STEPPER_DRIVERS - 1 - i : i;
@@ -227,14 +231,14 @@ void GcodeSuite::G34() {
// This allows the actual adjustment logic to be shared by both algorithms.
linear_fit_data lfd;
incremental_LSF_reset(&lfd);
- for (uint8_t i = 0; i < NUM_Z_STEPPER_DRIVERS; ++i) {
+ LOOP_L_N(i, NUM_Z_STEPPER_DRIVERS) {
SERIAL_ECHOLNPAIR("PROBEPT_", i + '1', ": ", z_measured[i]);
incremental_LSF(&lfd, z_stepper_align.xy[i], z_measured[i]);
}
finish_incremental_LSF(&lfd);
z_measured_min = 100000.0f;
- for (uint8_t i = 0; i < NUM_Z_STEPPER_DRIVERS; ++i) {
+ LOOP_L_N(i, NUM_Z_STEPPER_DRIVERS) {
z_measured[i] = -(lfd.A * z_stepper_align.stepper_xy[i].x + lfd.B * z_stepper_align.stepper_xy[i].y);
z_measured_min = _MIN(z_measured_min, z_measured[i]);
}
@@ -250,12 +254,37 @@ void GcodeSuite::G34() {
#endif
);
+ #if ENABLED(Z_STEPPER_ALIGN_KNOWN_STEPPER_POSITIONS)
+ // Check if the applied corrections go in the correct direction.
+ // Calculate the sum of the absolute deviations from the mean of the probe measurements.
+ // Compare to the last iteration to ensure it's getting better.
+
+ // Calculate mean value as a reference
+ float z_measured_mean = 0.0f;
+ LOOP_L_N(zstepper, NUM_Z_STEPPER_DRIVERS) z_measured_mean += z_measured[zstepper];
+ z_measured_mean /= NUM_Z_STEPPER_DRIVERS;
+
+ // Calculate the sum of the absolute deviations from the mean value
+ float z_align_level_indicator = 0.0f;
+ LOOP_L_N(zstepper, NUM_Z_STEPPER_DRIVERS)
+ z_align_level_indicator += ABS(z_measured[zstepper] - z_measured_mean);
+
+ // If it's getting worse, stop and throw an error
+ if (last_z_align_level_indicator < z_align_level_indicator * 0.7f) {
+ SERIAL_ECHOLNPGM("Decreasing accuracy detected.");
+ err_break = true;
+ break;
+ }
+
+ last_z_align_level_indicator = z_align_level_indicator;
+ #endif
+
// The following correction actions are to be enabled for select Z-steppers only
stepper.set_separate_multi_axis(true);
bool success_break = true;
// Correct the individual stepper offsets
- for (uint8_t zstepper = 0; zstepper < NUM_Z_STEPPER_DRIVERS; ++zstepper) {
+ LOOP_L_N(zstepper, NUM_Z_STEPPER_DRIVERS) {
// Calculate current stepper move
float z_align_move = z_measured[zstepper] - z_measured_min;
const float z_align_abs = ABS(z_align_move);
@@ -263,21 +292,16 @@ void GcodeSuite::G34() {
#if DISABLED(Z_STEPPER_ALIGN_KNOWN_STEPPER_POSITIONS)
// Optimize one iteration's correction based on the first measurements
if (z_align_abs) amplification = (iteration == 1) ? _MIN(last_z_align_move[zstepper] / z_align_abs, 2.0f) : z_auto_align_amplification;
- #endif
- // Check for less accuracy compared to last move
- if (last_z_align_move[zstepper] < z_align_abs * 0.7f) {
- SERIAL_ECHOLNPGM("Decreasing accuracy detected.");
- #if DISABLED(Z_STEPPER_ALIGN_KNOWN_STEPPER_POSITIONS)
+ // Check for less accuracy compared to last move
+ if (last_z_align_move[zstepper] < z_align_abs * 0.7f) {
+ SERIAL_ECHOLNPGM("Decreasing accuracy detected.");
adjustment_reverse = !adjustment_reverse;
- #else
- err_break = true;
- break;
- #endif
- }
+ }
- // Remember the alignment for the next iteration
- last_z_align_move[zstepper] = z_align_abs;
+ // Remember the alignment for the next iteration
+ last_z_align_move[zstepper] = z_align_abs;
+ #endif
// Stop early if all measured points achieve accuracy target
if (z_align_abs > z_auto_align_accuracy) success_break = false;
@@ -322,11 +346,9 @@ void GcodeSuite::G34() {
// Restore the active tool after homing
#if HOTENDS > 1
- tool_change(old_tool_index, (
+ tool_change(old_tool_index, (true
#if ENABLED(PARKING_EXTRUDER)
- false // Fetch the previous toolhead
- #else
- true
+ && false // Fetch the previous toolhead
#endif
));
#endif
@@ -367,10 +389,10 @@ void GcodeSuite::G34() {
void GcodeSuite::M422() {
if (!parser.seen_any()) {
- for (uint8_t i = 0; i < NUM_Z_STEPPER_DRIVERS; ++i)
+ LOOP_L_N(i, NUM_Z_STEPPER_DRIVERS)
SERIAL_ECHOLNPAIR_P(PSTR("M422 S"), i + '1', SP_X_STR, z_stepper_align.xy[i].x, SP_Y_STR, z_stepper_align.xy[i].y);
#if ENABLED(Z_STEPPER_ALIGN_KNOWN_STEPPER_POSITIONS)
- for (uint8_t i = 0; i < NUM_Z_STEPPER_DRIVERS; ++i)
+ LOOP_L_N(i, NUM_Z_STEPPER_DRIVERS)
SERIAL_ECHOLNPAIR_P(PSTR("M422 W"), i + '1', SP_X_STR, z_stepper_align.stepper_xy[i].x, SP_Y_STR, z_stepper_align.stepper_xy[i].y);
#endif
return;
--
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