Merge pull request Smoothieware#944 from Zaaphod/edge

Feature: Interpolate Arcs based on Maximum Error

ConfigSamples/AzteegX5Mini.delta/Version2/config

@@ -6,7 +6,10 @@ arm_radius                                   203.00           # this is the hori
 
 default_feed_rate                            4000             # Default rate ( mm/minute ) for G1/G2/G3 moves
 default_seek_rate                            4000             # Default rate ( mm/minute ) for G0 moves
-mm_per_arc_segment                           0.5              # Arcs are cut into segments ( lines ), this is the length for these segments.  Smaller values mean more resolution, higher values mean faster computation
+mm_per_arc_segment                           0.0              # Fixed length for line segments that divide arcs 0 to disable
+mm_max_arc_error                             0.01             # The maximum error for line segments that divide arcs 0 to disable
+                                                              # note it is invalid for both the above be 0
+                                                              # if both are used, will use largest segment length based on radius
 #mm_per_line_segment                          5                # Lines can be cut into segments ( not usefull with cartesian coordinates robots ).
 delta_segments_per_second                    100               # segments per second used for deltas
 

ConfigSamples/AzteegX5Mini.delta/config

@@ -6,7 +6,10 @@ arm_radius                                   203.00           # this is the hori
 
 default_feed_rate                            4000             # Default rate ( mm/minute ) for G1/G2/G3 moves
 default_seek_rate                            4000             # Default rate ( mm/minute ) for G0 moves
-mm_per_arc_segment                           0.5              # Arcs are cut into segments ( lines ), this is the length for these segments.  Smaller values mean more resolution, higher values mean faster computation
+mm_per_arc_segment                           0.0              # Fixed length for line segments that divide arcs 0 to disable
+mm_max_arc_error                             0.01             # The maximum error for line segments that divide arcs 0 to disable
+                                                              # note it is invalid for both the above be 0
+                                                              # if both are used, will use largest segment length based on radius
 #mm_per_line_segment                          5                # Lines can be cut into segments ( not usefull with cartesian coordinates robots ).
 delta_segments_per_second                    100               # segments per second used for deltas
 

ConfigSamples/AzteegX5Mini/Version2/config

@@ -1,7 +1,10 @@
 # Robot module configurations : general handling of movement G-codes and slicing into moves
 default_feed_rate                            4000             # Default rate ( mm/minute ) for G1/G2/G3 moves
 default_seek_rate                            4000             # Default rate ( mm/minute ) for G0 moves
-mm_per_arc_segment                           0.5              # Arcs are cut into segments ( lines ), this is the length for these segments.  Smaller values mean more resolution, higher values mean faster computation
+mm_per_arc_segment                           0.0              # Fixed length for line segments that divide arcs 0 to disable
+mm_max_arc_error                             0.01             # The maximum error for line segments that divide arcs 0 to disable
+                                                              # note it is invalid for both the above be 0
+                                                              # if both are used, will use largest segment length based on radius
 #mm_per_line_segment                          5                # Lines can be cut into segments ( not usefull with cartesian coordinates robots ).
 
 # Arm solution configuration : Cartesian robot. Translates mm positions into stepper positions

ConfigSamples/AzteegX5Mini/config

@@ -1,7 +1,10 @@
 # Robot module configurations : general handling of movement G-codes and slicing into moves
 default_feed_rate                            4000             # Default rate ( mm/minute ) for G1/G2/G3 moves
 default_seek_rate                            4000             # Default rate ( mm/minute ) for G0 moves
-mm_per_arc_segment                           0.5              # Arcs are cut into segments ( lines ), this is the length for these segments.  Smaller values mean more resolution, higher values mean faster computation
+mm_per_arc_segment                           0.0              # Fixed length for line segments that divide arcs 0 to disable
+mm_max_arc_error                             0.01             # The maximum error for line segments that divide arcs 0 to disable
+                                                              # note it is invalid for both the above be 0
+                                                              # if both are used, will use largest segment length based on radius
 #mm_per_line_segment                          5                # Lines can be cut into segments ( not usefull with cartesian coordinates robots ).
 
 # Arm solution configuration : Cartesian robot. Translates mm positions into stepper positions

ConfigSamples/Smoothieboard.delta/config

@@ -2,9 +2,10 @@
 # Robot module configurations : general handling of movement G-codes and slicing into moves
 default_feed_rate                            4000             # Default rate ( mm/minute ) for G1/G2/G3 moves
 default_seek_rate                            4000             # Default rate ( mm/minute ) for G0 moves
-mm_per_arc_segment                           0.5              # Arcs are cut into segments ( lines ), this is the length for
-                                                              # these segments.  Smaller values mean more resolution,
-                                                              # higher values mean faster computation
+mm_per_arc_segment                           0.0              # Fixed length for line segments that divide arcs 0 to disable
+mm_max_arc_error                             0.01             # The maximum error for line segments that divide arcs 0 to disable
+                                                              # note it is invalid for both the above be 0
+                                                              # if both are used, will use largest segment length based on radius
 #mm_per_line_segment                         0.5              # Lines can be cut into segments ( not useful with cartesian
                                                               # coordinates robots ).
 delta_segments_per_second                    100              # for deltas only same as in Marlin/Delta, set to 0 to disable

ConfigSamples/Smoothieboard/config

@@ -2,9 +2,10 @@
 ## Robot module configurations : general handling of movement G-codes and slicing into moves
 default_feed_rate                            4000             # Default rate ( mm/minute ) for G1/G2/G3 moves
 default_seek_rate                            4000             # Default rate ( mm/minute ) for G0 moves
-mm_per_arc_segment                           0.5              # Arcs are cut into segments ( lines ), this is the length for
-                                                              # these segments.  Smaller values mean more resolution,
-                                                              # higher values mean faster computation
+mm_per_arc_segment                           0.0              # Fixed length for line segments that divide arcs 0 to disable
+mm_max_arc_error                             0.01             # The maximum error for line segments that divide arcs 0 to disable
+                                                              # note it is invalid for both the above be 0
+                                                              # if both are used, will use largest segment length based on radius
 #mm_per_line_segment                          5                # Lines can be cut into segments ( not usefull with cartesian
                                                               # coordinates robots ).
 

ConfigSamples/rotary.delta/config

@@ -2,9 +2,10 @@
 # Robot module configurations : general handling of movement G-codes and slicing into moves
 default_feed_rate                            4000             # Default rate ( mm/minute ) for G1/G2/G3 moves
 default_seek_rate                            4000             # Default rate ( mm/minute ) for G0 moves
-mm_per_arc_segment                           0.5              # Arcs are cut into segments ( lines ), this is the length for
-                                                              # these segments.  Smaller values mean more resolution,
-                                                              # higher values mean faster computation
+mm_per_arc_segment                           0.0              # Fixed length for line segments that divide arcs 0 to disable
+mm_max_arc_error                             0.01             # The maximum error for line segments that divide arcs 0 to disable
+                                                              # note it is invalid for both the above be 0
+                                                              # if both are used, will use largest segment length based on radius
 #mm_per_line_segment                         0.5              # Lines can be cut into segments ( not useful with cartesian
                                                               # coordinates robots ).
 delta_segments_per_second                    100              # for deltas only same as in Marlin/Delta, set to 0 to disable

src/modules/robot/Robot.cpp

@@ -46,6 +46,7 @@ using std::string;
 #define  mm_per_line_segment_checksum        CHECKSUM("mm_per_line_segment")
 #define  delta_segments_per_second_checksum  CHECKSUM("delta_segments_per_second")
 #define  mm_per_arc_segment_checksum         CHECKSUM("mm_per_arc_segment")
+#define  mm_max_arc_error_checksum           CHECKSUM("mm_max_arc_error")
 #define  arc_correction_checksum             CHECKSUM("arc_correction")
 #define  x_axis_max_speed_checksum           CHECKSUM("x_axis_max_speed")
 #define  y_axis_max_speed_checksum           CHECKSUM("y_axis_max_speed")
@@ -180,7 +181,8 @@ void Robot::load_config()
     this->seek_rate           = THEKERNEL->config->value(default_seek_rate_checksum   )->by_default(  100.0F)->as_number();
     this->mm_per_line_segment = THEKERNEL->config->value(mm_per_line_segment_checksum )->by_default(    0.0F)->as_number();
     this->delta_segments_per_second = THEKERNEL->config->value(delta_segments_per_second_checksum )->by_default(0.0f   )->as_number();
-    this->mm_per_arc_segment  = THEKERNEL->config->value(mm_per_arc_segment_checksum  )->by_default(    0.5f)->as_number();
+    this->mm_per_arc_segment  = THEKERNEL->config->value(mm_per_arc_segment_checksum  )->by_default(    0.0f)->as_number();
+    this->mm_max_arc_error    = THEKERNEL->config->value(mm_max_arc_error_checksum    )->by_default(   0.01f)->as_number();
     this->arc_correction      = THEKERNEL->config->value(arc_correction_checksum      )->by_default(    5   )->as_number();
 
     this->max_speeds[X_AXIS]  = THEKERNEL->config->value(x_axis_max_speed_checksum    )->by_default(60000.0F)->as_number() / 60.0F;
@@ -1018,9 +1020,18 @@ bool Robot::append_arc(Gcode * gcode, const float target[], const float offset[]
     // Mark the gcode as having a known distance
     this->distance_in_gcode_is_known( gcode );
 
+    // limit segments by maximum arc error
+    float arc_segment = this->mm_per_arc_segment;
+    if ((this->mm_max_arc_error > 0) && (2 * radius > this->mm_max_arc_error)) {
+        float min_err_segment = 2 * sqrtf((this->mm_max_arc_error * (2 * radius - this->mm_max_arc_error)));
+        if (this->mm_per_arc_segment < min_err_segment) {
+            arc_segment = min_err_segment;
+        }
+    }
     // Figure out how many segments for this gcode
-    uint16_t segments = floorf(gcode->millimeters_of_travel / this->mm_per_arc_segment);
+    uint16_t segments = ceilf(gcode->millimeters_of_travel / arc_segment);
 
+  //printf("Radius %f - Segment Length %f - Number of Segments %d\r\n",radius,arc_segment,segments);  // Testing Purposes ONLY   
     float theta_per_segment = angular_travel / segments;
     float linear_per_segment = linear_travel / segments;
 

src/modules/robot/Robot.h

@@ -107,6 +107,7 @@ class Robot : public Module {
         float feed_rate;                                     // Current rate for feeding moves ( mm/min )
         float mm_per_line_segment;                           // Setting : Used to split lines into segments
         float mm_per_arc_segment;                            // Setting : Used to split arcs into segments
+        float mm_max_arc_error;                              // Setting : Used to limit total arc segments to max error
         float delta_segments_per_second;                     // Setting : Used to split lines into segments for delta based on speed
         float seconds_per_minute;                            // for realtime speed change