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Fix G34 "Decreasing accuracy" bug (#17013)

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Co-authored-by: Scott Lahteine <thinkyhead@users.noreply.github.com>
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jufimu12 2020-02-28 18:42:51 +01:00 committed by GitHub
parent 97e87d8262
commit ac755fce82
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1 changed files with 47 additions and 25 deletions
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72
Marlin/src/gcode/calibrate/G34_M422.cpp
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@ -155,8 +155,12 @@ void GcodeSuite::G34() {
// Move the Z coordinate realm towards the positive - dirty trick // Move the Z coordinate realm towards the positive - dirty trick
current_position.z -= z_probe * 0.5f; 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), #if DISABLED(Z_STEPPER_ALIGN_KNOWN_STEPPER_POSITIONS)
z_measured[NUM_Z_STEPPER_DRIVERS] = { 0 }, 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, z_maxdiff = 0.0f,
amplification = z_auto_align_amplification; amplification = z_auto_align_amplification;
@ -167,7 +171,7 @@ void GcodeSuite::G34() {
bool adjustment_reverse = false; bool adjustment_reverse = false;
#endif #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."); if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPGM("> probing all positions.");
SERIAL_ECHOLNPAIR("\nITERATION: ", int(iteration + 1)); SERIAL_ECHOLNPAIR("\nITERATION: ", int(iteration + 1));
@ -177,7 +181,7 @@ void GcodeSuite::G34() {
z_measured_max = -100000.0f; z_measured_max = -100000.0f;
// Probe all positions (one per Z-Stepper) // 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 // iteration odd/even --> downward / upward stepper sequence
const uint8_t iprobe = (iteration & 1) ? NUM_Z_STEPPER_DRIVERS - 1 - i : i; 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. // This allows the actual adjustment logic to be shared by both algorithms.
linear_fit_data lfd; linear_fit_data lfd;
incremental_LSF_reset(&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]); SERIAL_ECHOLNPAIR("PROBEPT_", i + '1', ": ", z_measured[i]);
incremental_LSF(&lfd, z_stepper_align.xy[i], z_measured[i]); incremental_LSF(&lfd, z_stepper_align.xy[i], z_measured[i]);
} }
finish_incremental_LSF(&lfd); finish_incremental_LSF(&lfd);
z_measured_min = 100000.0f; 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[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]); z_measured_min = _MIN(z_measured_min, z_measured[i]);
} }
@ -250,12 +254,37 @@ void GcodeSuite::G34() {
#endif #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 // The following correction actions are to be enabled for select Z-steppers only
stepper.set_separate_multi_axis(true); stepper.set_separate_multi_axis(true);
bool success_break = true; bool success_break = true;
// Correct the individual stepper offsets // 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 // Calculate current stepper move
float z_align_move = z_measured[zstepper] - z_measured_min; float z_align_move = z_measured[zstepper] - z_measured_min;
const float z_align_abs = ABS(z_align_move); const float z_align_abs = ABS(z_align_move);
@ -263,21 +292,16 @@ void GcodeSuite::G34() {
#if DISABLED(Z_STEPPER_ALIGN_KNOWN_STEPPER_POSITIONS) #if DISABLED(Z_STEPPER_ALIGN_KNOWN_STEPPER_POSITIONS)
// Optimize one iteration's correction based on the first measurements // 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; 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 // Check for less accuracy compared to last move
if (last_z_align_move[zstepper] < z_align_abs * 0.7f) { if (last_z_align_move[zstepper] < z_align_abs * 0.7f) {
SERIAL_ECHOLNPGM("Decreasing accuracy detected."); SERIAL_ECHOLNPGM("Decreasing accuracy detected.");
#if DISABLED(Z_STEPPER_ALIGN_KNOWN_STEPPER_POSITIONS)
adjustment_reverse = !adjustment_reverse; adjustment_reverse = !adjustment_reverse;
#else }
err_break = true;
break;
#endif
}
// Remember the alignment for the next iteration // Remember the alignment for the next iteration
last_z_align_move[zstepper] = z_align_abs; last_z_align_move[zstepper] = z_align_abs;
#endif
// Stop early if all measured points achieve accuracy target // Stop early if all measured points achieve accuracy target
if (z_align_abs > z_auto_align_accuracy) success_break = false; if (z_align_abs > z_auto_align_accuracy) success_break = false;
@ -322,11 +346,9 @@ void GcodeSuite::G34() {
// Restore the active tool after homing // Restore the active tool after homing
#if HOTENDS > 1 #if HOTENDS > 1
tool_change(old_tool_index, ( tool_change(old_tool_index, (true
#if ENABLED(PARKING_EXTRUDER) #if ENABLED(PARKING_EXTRUDER)
false // Fetch the previous toolhead && false // Fetch the previous toolhead
#else
true
#endif #endif
)); ));
#endif #endif
@ -367,10 +389,10 @@ void GcodeSuite::G34() {
void GcodeSuite::M422() { void GcodeSuite::M422() {
if (!parser.seen_any()) { 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); 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) #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); 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 #endif
return; return;