Smooth Linear Advance (Testing)

Marlin/Configuration_adv.h

@@ -2360,13 +2360,24 @@
 #define LIN_ADVANCE
 #if ENABLED(LIN_ADVANCE)
   #if ENABLED(DISTINCT_E_FACTORS)
-    #define ADVANCE_K { 0.00 }    // (mm) Compression length per 1mm/s extruder speed, per extruder
+    #define ADVANCE_K { 0.00 }     // (mm) Compression length per 1mm/s extruder speed, per extruder
   #else
-    #define ADVANCE_K 0.00        // (mm) Compression length applying to all extruders
+    #define ADVANCE_K 0.00         // (mm) Compression length applying to all extruders
+  #endif
+  //#define ADVANCE_K_EXTRA        // Add a second linear advance constant, configurable with M900 L.
+  //#define LA_DEBUG               // Print debug information to serial during operation. Disable for production use.
+  //#define EXPERIMENTAL_I2S_LA    // Allow I2S_STEPPER_STREAM to be used with LA. Performance degrades as the LA step rate reaches ~20kHz.
+  #define SMOOTH_LIN_ADV           // Removes motion acceleration limitation by allowing to gradual ramp up of nozzle pressure
+  #if ENABLED(SMOOTH_LIN_ADV)
+    #define ADVANCE_TAU 0.01       // (secs) Smoothing time to reduce extruder acceleration due to linear advance.
+                                   // It is also the time ahead the smoother needs to look in the planner
+                                   // so the planner needs to have enough blocks loaded.
+                                   // for k=0.04 at 10k acceleration and an orbiter 2, it can be as low as 0.0075.
+                                   // The lower the better until stepper skipps
+                                   // Higher k and higher print accelerations may require larger tau to avoid skipping steps
+    #define SMOOTH_LIN_ADV_HZ 5000 // How often to update extruder speed
+    //#define INPUT_SHAPING_E_SYNCH// Synchronize the extruder shaped xy axes (increrses precision)
   #endif
-  //#define ADVANCE_K_EXTRA       // Add a second linear advance constant, configurable with M900 L.
-  //#define LA_DEBUG              // Print debug information to serial during operation. Disable for production use.
-  //#define EXPERIMENTAL_I2S_LA   // Allow I2S_STEPPER_STREAM to be used with LA. Performance degrades as the LA step rate reaches ~20kHz.
 #endif
 
 /**

Marlin/src/gcode/feature/advance/M900.cpp

@@ -26,6 +26,7 @@
 
 #include "../../gcode.h"
 #include "../../../module/planner.h"
+#include "../../../module/stepper.h"
 
 #if ENABLED(ADVANCE_K_EXTRA)
   float other_extruder_advance_K[DISTINCT_E];
@@ -105,6 +106,18 @@ void GcodeSuite::M900() {
 
   #endif
 
+  #if ENABLED(SMOOTH_LIN_ADV)
+    if (parser.seenval('U')) {
+      const float tau = parser.value_float();
+      if (WITHIN(tau, 0, .5)) {
+        planner.synchronize();
+        Stepper::set_advance_tau(tau);
+      }
+      else
+        echo_value_oor('U');
+    }
+  #endif
+
   if (newK != oldK) {
     planner.synchronize();
     kref = newK;
@@ -134,6 +147,9 @@ void GcodeSuite::M900() {
         EXTRUDER_LOOP() SERIAL_ECHO(C(' '), C('0' + e), C(':'), planner.extruder_advance_K[e]);
         SERIAL_EOL();
       #endif
+      #if ENABLED(SMOOTH_LIN_ADV)
+        SERIAL_ECHOLNPGM("Advance TAU=", Stepper::get_advance_tau());
+      #endif
 
     #endif
   }
@@ -153,6 +169,9 @@ void GcodeSuite::M900_report(const bool forReplay/*=true*/) {
       SERIAL_ECHOLNPGM("  M900 T", e, " K", planner.extruder_advance_K[e]);
     }
   #endif
+  #if ENABLED(SMOOTH_LIN_ADV)
+    SERIAL_ECHOLNPGM("  M900 U", Stepper::get_advance_tau());
+  #endif
 }
 
 #endif // LIN_ADVANCE

Marlin/src/inc/SanityCheck.h

@@ -852,6 +852,24 @@ static_assert(COUNT(arm) == LOGICAL_AXES, "AXIS_RELATIVE_MODES must contain " _L
   #if ENABLED(DIRECT_STEPPING)
     #error "DIRECT_STEPPING is incompatible with LIN_ADVANCE. (Extrusion is controlled externally by the Step Daemon.)"
   #endif
+
+  #if ENABLED(SMOOTH_LIN_ADV)
+    #if ENABLED(MIXING_EXTRUDER)
+      #warning "SMOOTH_LIN_ADV with MIXING_EXTRUDER is not tested."
+    #endif
+    #if DISABLED(CPU_32_BIT)
+      #error "SMOOTH_LIN_ADV requires a 32-bit CPU."
+    #endif
+    static_assert(DISTINCT_E == 1, "SMOOTH_LIN_ADV is not compatible with multiple extruders.");
+    #if ENABLED(S_CURVE_ACCELERATION)
+      //#warning "SMOOTH_LIN_ADV together with S_CURVE_ACCELERATION is untested."
+    #endif
+
+    #if ENABLED(INPUT_SHAPING_E_SYNCH)
+      static_assert(ENABLED(INPUT_SHAPING_X), "INPUT_SHAPING_E_SYNCH requires INPUT_SHAPING_X.");
+      static_assert(ENABLED(INPUT_SHAPING_Y), "INPUT_SHAPING_E_SYNCH requires INPUT_SHAPING_Y.");
+    #endif
+  #endif
 #endif
 
 /**

Marlin/src/lcd/e3v2/proui/dwin.cpp

@@ -161,6 +161,9 @@ HMI_data_t HMI_data;
 #if ENABLED(PROUI_MESH_EDIT)
   MeshSet_t meshSet;
 #endif
+#if ENABLED(SMOOTH_LIN_ADV)
+  smoothLA_t editable;
+#endif
 
 enum SelectItem : uint8_t {
   PAGE_PRINT = 0,
@@ -524,7 +527,7 @@ void DWIN_DrawStatusMessage() {
 void Draw_Print_Labels() {
   DWINUI::Draw_String( 46, 173, GET_TEXT_F(MSG_INFO_PRINT_TIME));
   DWINUI::Draw_String(181, 173, GET_TEXT_F(MSG_REMAINING_TIME));
-  TERN_(SHOW_INTERACTION_TIME, DWINUI::Draw_String(100, 215, F("Until Filament Change"));)
+  TERN_(SHOuW_INTERACTION_TIME, DWINUI::Draw_String(100, 215, F("Until Filament Change"));)
 }
 
 static uint8_t _percent_done = 100;
@@ -3094,6 +3097,13 @@ void ApplyMaxAccel() { planner.set_max_acceleration(HMI_value.axis, MenuData.Val
 
 #if ALL(PROUI_ITEM_ADVK, LIN_ADVANCE)
   void SetLA_K() { SetPFloatOnClick(0, 10, 3); }
+  #if ENABLED(SMOOTH_LIN_ADV)
+    void UpdateSmoothLA() {
+      editable.decimal = Stepper::get_advance_tau();
+    }
+    void ApplySmoothLA() { Stepper::set_advance_tau(MenuData.Value); }
+    void SetSmoothLA() { SetPFloatOnClick(0, 0.5, 1, ApplySmoothLA, UpdateSmoothLA); }
+  #endif
 #endif
 
 #if HAS_X_AXIS
@@ -3520,7 +3530,7 @@ void Draw_Tune_Menu() {
     if (laser_device.is_laser_device()) return LCD_MESSAGE_F("Not available in laser mode");
   #endif
   checkkey = Menu;
-  if (SET_MENU(TuneMenu, MSG_TUNE, 23)) {
+  if (SET_MENU(TuneMenu, MSG_TUNE, 24)) {
     BACK_ITEM(Goto_PrintProcess);
     #if HAS_LCD_BRIGHTNESS
       MENU_ITEM(ICON_Box, MSG_BRIGHTNESS_OFF, onDrawMenuItem, TurnOffBacklight);
@@ -3572,6 +3582,9 @@ void Draw_Tune_Menu() {
     #endif
     #if ALL(PROUI_ITEM_ADVK, LIN_ADVANCE)
       EDIT_ITEM(ICON_MaxAccelerated, MSG_ADVANCE_K, onDrawPFloat3Menu, SetLA_K, &planner.extruder_advance_K[EXT]);
+      #if ENABLED(SMOOTH_LIN_ADV)
+        EDIT_ITEM(ICON_MaxSpeed, MSG_ADVANCE_TAU, onDrawPFloat2Menu, SetSmoothLA, &editable.decimal);
+      #endif
     #endif
     #if ENABLED(EDITABLE_DISPLAY_TIMEOUT)
       EDIT_ITEM(ICON_RemainTime, MSG_SCREEN_TIMEOUT, onDrawPInt8Menu, SetTimer, &ui.backlight_timeout_minutes);
@@ -3707,7 +3720,7 @@ void Draw_Tune_Menu() {
 
 void Draw_Motion_Menu() {
   checkkey = Menu;
-  if (SET_MENU(MotionMenu, MSG_MOTION, 9)) {
+  if (SET_MENU(MotionMenu, MSG_MOTION, 10)) {
     BACK_ITEM(Draw_Control_Menu);
     MENU_ITEM(ICON_MaxSpeed, MSG_SPEED, onDrawSubMenu, Draw_MaxSpeed_Menu);
     MENU_ITEM(ICON_MaxAccelerated, MSG_ACCELERATION, onDrawSubMenu, Draw_MaxAccel_Menu);
@@ -3730,6 +3743,9 @@ void Draw_Motion_Menu() {
     #endif
     #if ALL(PROUI_ITEM_ADVK, LIN_ADVANCE)
       EDIT_ITEM(ICON_MaxAccelerated, MSG_ADVANCE_K, onDrawPFloat3Menu, SetLA_K, &planner.extruder_advance_K[EXT]);
+      #if ENABLED(SMOOTH_LIN_ADV)
+        EDIT_ITEM(ICON_MaxSpeed, MSG_ADVANCE_TAU, onDrawPFloat2Menu, SetSmoothLA, &editable.decimal);
+      #endif
     #endif
     #if ENABLED(ADAPTIVE_STEP_SMOOTHING_TOGGLE)
       EDIT_ITEM(ICON_CloseMotor, MSG_STEP_SMOOTHING, onDrawChkbMenu, SetAdaptiveStepSmoothing, &stepper.adaptive_step_smoothing_enabled);

Marlin/src/lcd/e3v2/proui/dwin.h

@@ -45,6 +45,14 @@
 
 extern char DateTime[16+1];
 
+#if ENABLED(SMOOTH_LIN_ADV)
+  typedef struct {
+    float decimal;
+  } smoothLA_t;
+
+  extern smoothLA_t editable;
+#endif
+
 enum processID : uint8_t {
   // Process ID
   MainMenu,

Marlin/src/lcd/language/language_en.h

@@ -498,6 +498,7 @@ namespace LanguageNarrow_en {
   LSTR MSG_MAX_BELT_LEN                   = _UxGT("Max Belt Len");
   LSTR MSG_LINEAR_ADVANCE                 = _UxGT("Linear Advance");
   LSTR MSG_ADVANCE_K                      = _UxGT("Advance K");
+  LSTR MSG_ADVANCE_TAU                    = _UxGT("Advance TAU");
   LSTR MSG_ADVANCE_K_E                    = _UxGT("Advance K *");
   LSTR MSG_CONTRAST                       = _UxGT("LCD Contrast");
   LSTR MSG_BRIGHTNESS                     = _UxGT("LCD Brightness");

Marlin/src/lcd/menu/menu_advanced.cpp

@@ -115,6 +115,10 @@ void menu_backlash();
           EDIT_ITEM_N(float42_52, e, MSG_ADVANCE_K_E, &planner.extruder_advance_K[e], 0, 10);
       #endif
     #endif
+    #if ENABLED(SMOOTH_LIN_ADV)
+      editable.decimal = Stepper::get_advance_tau();
+      EDIT_ITEM(float54, MSG_ADVANCE_TAU, &editable.decimal, 0.0f, 0.5f, []{ Stepper::set_advance_tau(editable.decimal); });
+    #endif
 
     #if DISABLED(NO_VOLUMETRICS)
       EDIT_ITEM(bool, MSG_VOLUMETRIC_ENABLED, &parser.volumetric_enabled, planner.calculate_volumetric_multipliers);
@@ -727,6 +731,10 @@ void menu_advanced_settings() {
       EXTRUDER_LOOP()
         EDIT_ITEM_N(float42_52, n, MSG_ADVANCE_K_E, &planner.extruder_advance_K[e], 0, 10);
     #endif
+    #if ENABLED(SMOOTH_LIN_ADV)
+      editable.decimal = Stepper::get_advance_tau();
+      EDIT_ITEM(float54, MSG_ADVANCE_TAU, &editable.decimal, 0.0f, 0.5f, []{ Stepper::set_advance_tau(editable.decimal); });
+    #endif
   #endif
 
   // M540 S - Abort on endstop hit when SD printing

Marlin/src/lcd/menu/menu_tune.cpp

@@ -31,6 +31,7 @@
 #include "menu_item.h"
 #include "../../module/motion.h"
 #include "../../module/planner.h"
+#include "../../module/stepper.h"
 #include "../../module/temperature.h"
 #include "../../MarlinCore.h"
 
@@ -221,6 +222,11 @@ void menu_tune() {
     #endif
   #endif
 
+  #if ENABLED(SMOOTH_LIN_ADV)
+    editable.decimal = Stepper::get_advance_tau();
+    EDIT_ITEM(float54, MSG_ADVANCE_TAU, &editable.decimal, 0.0f, 0.5f, []{ Stepper::set_advance_tau(editable.decimal); });
+  #endif
+
   //
   // Babystep X:
   // Babystep Y: