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BugFix for incorrect E-speed calculation

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The extrusion speed was wrong due to a not high enough precision of
esteps to XY steps, therefore now the target float values are used to
calculate the ratio between XY movement and extrusion speed.
The e_speed_multiplier8 was replaced by an absolute multiplier called
abs_adv_steps_multiplier8, therefore one multiplication and bitshift can
be saved inside the stepper ISR. Due to this, also extruder_advance_k is
better suited inside the planner and not the stepper files any more.
This commit is contained in:
Sebastianv650 2016-10-31 16:17:30 +01:00
parent fa6bf12697
commit f9bea7968f
5 changed files with 48 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Marlin/Marlin_main.cpp
View File

@ -6988,7 +6988,7 @@ inline void gcode_M503() {
*/
inline void gcode_M905() {
stepper.synchronize();
stepper.advance_M905(code_seen('K') ? code_value_float() : -1.0);
planner.advance_M905(code_seen('K') ? code_value_float() : -1.0);
}
#endif

31
Marlin/planner.cpp
View File

@ -131,6 +131,11 @@ float Planner::previous_speed[NUM_AXIS],
long Planner::axis_segment_time[2][3] = { {MAX_FREQ_TIME + 1, 0, 0}, {MAX_FREQ_TIME + 1, 0, 0} };
#endif
#if ENABLED(LIN_ADVANCE)
float Planner::extruder_advance_k = LIN_ADVANCE_K;
float Planner::position_float[NUM_AXIS] = { 0 };
#endif
/**
* Class and Instance Methods
*/
@ -140,6 +145,9 @@ Planner::Planner() { init(); }
void Planner::init() {
block_buffer_head = block_buffer_tail = 0;
ZERO(position);
#if ENABLED(LIN_ADVANCE)
ZERO(position_float);
#endif
ZERO(previous_speed);
previous_nominal_speed = 0.0;
#if ABL_PLANAR
@ -605,6 +613,14 @@ void Planner::_buffer_line(const float &a, const float &b, const float &c, const
lround(e * axis_steps_per_mm[E_AXIS])
};
#if ENABLED(LIN_ADVANCE)
float target_float[XYZE] = {a, b, c, e};
float de_float = target_float[E_AXIS] - position_float[E_AXIS];
float mm_D_float = sqrt(sq(target_float[X_AXIS] - position_float[X_AXIS]) + sq(target_float[Y_AXIS] - position_float[Y_AXIS]));
memcpy(position_float, target_float, sizeof(position_float));
#endif
long da = target[X_AXIS] - position[X_AXIS],
db = target[Y_AXIS] - position[Y_AXIS],
dc = target[Z_AXIS] - position[Z_AXIS];
@ -1232,12 +1248,12 @@ void Planner::_buffer_line(const float &a, const float &b, const float &c, const
// This leads to an enormous number of advance steps due to a huge e_acceleration.
// The math is correct, but you don't want a retract move done with advance!
// So this situation is filtered out here.
if (!esteps || (!block->steps[X_AXIS] && !block->steps[Y_AXIS]) || stepper.get_advance_k() == 0 || (uint32_t)esteps == block->step_event_count) {
if (!esteps || (!block->steps[X_AXIS] && !block->steps[Y_AXIS]) || extruder_advance_k == 0.0 || (uint32_t)esteps == block->step_event_count) {
block->use_advance_lead = false;
}
else {
block->use_advance_lead = true;
block->e_speed_multiplier8 = (esteps << 8) / block->step_event_count;
block->abs_adv_steps_multiplier8 = lround(extruder_advance_k * (de_float / mm_D_float) * block->nominal_speed / (float)block->nominal_rate * axis_steps_per_mm[Z_AXIS] * 256.0);
}
#elif ENABLED(ADVANCE)
@ -1354,3 +1370,14 @@ void Planner::refresh_positioning() {
}
#endif
#if ENABLED(LIN_ADVANCE)
void Planner::advance_M905(const float &k) {
if (k >= 0.0) extruder_advance_k = k;
SERIAL_ECHO_START;
SERIAL_ECHOPAIR("Advance factor: ", extruder_advance_k);
SERIAL_EOL;
}
#endif

11
Marlin/planner.h
View File

@ -95,7 +95,7 @@ typedef struct {
// Advance extrusion
#if ENABLED(LIN_ADVANCE)
bool use_advance_lead;
int16_t e_speed_multiplier8; // Factorised by 2^8 to avoid float
uint32_t abs_adv_steps_multiplier8; // Factorised by 2^8 to avoid float
#elif ENABLED(ADVANCE)
int32_t advance_rate;
volatile int32_t initial_advance;
@ -197,6 +197,11 @@ class Planner {
static long axis_segment_time[2][3];
#endif
#if ENABLED(LIN_ADVANCE)
static float position_float[NUM_AXIS];
static float extruder_advance_k;
#endif
public:
/**
@ -246,6 +251,10 @@ class Planner {
#endif
#if ENABLED(LIN_ADVANCE)
void advance_M905(const float &k);
#endif
/**
* Planner::_buffer_line
*

24
Marlin/stepper.cpp
View File

@ -96,8 +96,7 @@ volatile uint32_t Stepper::step_events_completed = 0; // The number of step even
#if ENABLED(LIN_ADVANCE)
volatile int Stepper::e_steps[E_STEPPERS];
int Stepper::extruder_advance_k = LIN_ADVANCE_K,
Stepper::final_estep_rate,
int Stepper::final_estep_rate,
Stepper::current_estep_rate[E_STEPPERS],
Stepper::current_adv_steps[E_STEPPERS];
#else
@ -534,7 +533,7 @@ void Stepper::isr() {
#if ENABLED(LIN_ADVANCE)
if (current_block->use_advance_lead) {
int delta_adv_steps = (((long)extruder_advance_k * current_estep_rate[TOOL_E_INDEX]) >> 9) - current_adv_steps[TOOL_E_INDEX];
int delta_adv_steps = current_estep_rate[TOOL_E_INDEX] - current_adv_steps[TOOL_E_INDEX];
current_adv_steps[TOOL_E_INDEX] += delta_adv_steps;
#if ENABLED(MIXING_EXTRUDER)
// Mixing extruders apply advance lead proportionally
@ -572,9 +571,9 @@ void Stepper::isr() {
if (current_block->use_advance_lead) {
#if ENABLED(MIXING_EXTRUDER)
MIXING_STEPPERS_LOOP(j)
current_estep_rate[j] = ((uint32_t)acc_step_rate * current_block->e_speed_multiplier8 * current_block->step_event_count / current_block->mix_event_count[j]) >> 8;
current_estep_rate[j] = ((uint32_t)acc_step_rate * current_block->abs_adv_steps_multiplier8 * current_block->step_event_count / current_block->mix_event_count[j]) >> 17;
#else
current_estep_rate[TOOL_E_INDEX] = ((uint32_t)acc_step_rate * current_block->e_speed_multiplier8) >> 8;
current_estep_rate[TOOL_E_INDEX] = ((uint32_t)acc_step_rate * current_block->abs_adv_steps_multiplier8) >> 17;
#endif
}
@ -624,9 +623,9 @@ void Stepper::isr() {
if (current_block->use_advance_lead) {
#if ENABLED(MIXING_EXTRUDER)
MIXING_STEPPERS_LOOP(j)
current_estep_rate[j] = ((uint32_t)step_rate * current_block->e_speed_multiplier8 * current_block->step_event_count / current_block->mix_event_count[j]) >> 8;
current_estep_rate[j] = ((uint32_t)step_rate * current_block->abs_adv_steps_multiplier8 * current_block->step_event_count / current_block->mix_event_count[j]) >> 17;
#else
current_estep_rate[TOOL_E_INDEX] = ((uint32_t)step_rate * current_block->e_speed_multiplier8) >> 8;
current_estep_rate[TOOL_E_INDEX] = ((uint32_t)step_rate * current_block->abs_adv_steps_multiplier8) >> 17;
#endif
}
@ -1350,14 +1349,3 @@ void Stepper::report_positions() {
}
#endif // HAS_MICROSTEPS
#if ENABLED(LIN_ADVANCE)
void Stepper::advance_M905(const float &k) {
if (k >= 0) extruder_advance_k = k;
SERIAL_ECHO_START;
SERIAL_ECHOPAIR("Advance factor: ", extruder_advance_k);
SERIAL_EOL;
}
#endif // LIN_ADVANCE

10
Marlin/stepper.h
View File

@ -109,7 +109,6 @@ class Stepper {
static volatile unsigned char eISR_Rate;
#if ENABLED(LIN_ADVANCE)
static volatile int e_steps[E_STEPPERS];
static int extruder_advance_k;
static int final_estep_rate;
static int current_estep_rate[E_STEPPERS]; // Actual extruder speed [steps/s]
static int current_adv_steps[E_STEPPERS]; // The amount of current added esteps due to advance.
@ -277,11 +276,6 @@ class Stepper {
return endstops_trigsteps[axis] * planner.steps_to_mm[axis];
}
#if ENABLED(LIN_ADVANCE)
void advance_M905(const float &k);
FORCE_INLINE int get_advance_k() { return extruder_advance_k; }
#endif
private:
static FORCE_INLINE unsigned short calc_timer(unsigned short step_rate) {
@ -367,8 +361,8 @@ class Stepper {
#if ENABLED(LIN_ADVANCE)
if (current_block->use_advance_lead) {
current_estep_rate[current_block->active_extruder] = ((unsigned long)acc_step_rate * current_block->e_speed_multiplier8) >> 8;
final_estep_rate = (current_block->nominal_rate * current_block->e_speed_multiplier8) >> 8;
current_estep_rate[current_block->active_extruder] = ((unsigned long)acc_step_rate * current_block->abs_adv_steps_multiplier8) >> 17;
final_estep_rate = (current_block->nominal_rate * current_block->abs_adv_steps_multiplier8) >> 17;
}
#endif