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706 lines
30 KiB
706 lines
30 KiB
/*
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planner.c - buffers movement commands and manages the acceleration profile plan
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Part of Grbl
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Copyright (c) 2009-2011 Simen Svale Skogsrud
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Grbl is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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Grbl is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with Grbl. If not, see <http://www.gnu.org/licenses/>.
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*/
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/* The ring buffer implementation gleaned from the wiring_serial library by David A. Mellis. */
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/*
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Reasoning behind the mathematics in this module (in the key of 'Mathematica'):
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s == speed, a == acceleration, t == time, d == distance
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Basic definitions:
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Speed[s_, a_, t_] := s + (a*t)
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Travel[s_, a_, t_] := Integrate[Speed[s, a, t], t]
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Distance to reach a specific speed with a constant acceleration:
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Solve[{Speed[s, a, t] == m, Travel[s, a, t] == d}, d, t]
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d -> (m^2 - s^2)/(2 a) --> estimate_acceleration_distance()
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Speed after a given distance of travel with constant acceleration:
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Solve[{Speed[s, a, t] == m, Travel[s, a, t] == d}, m, t]
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m -> Sqrt[2 a d + s^2]
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DestinationSpeed[s_, a_, d_] := Sqrt[2 a d + s^2]
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When to start braking (di) to reach a specified destionation speed (s2) after accelerating
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from initial speed s1 without ever stopping at a plateau:
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Solve[{DestinationSpeed[s1, a, di] == DestinationSpeed[s2, a, d - di]}, di]
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di -> (2 a d - s1^2 + s2^2)/(4 a) --> intersection_distance()
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IntersectionDistance[s1_, s2_, a_, d_] := (2 a d - s1^2 + s2^2)/(4 a)
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*/
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//#include <inttypes.h>
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//#include <math.h>
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//#include <stdlib.h>
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#include "Marlin.h"
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#include "Configuration.h"
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#include "pins.h"
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#include "fastio.h"
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#include "planner.h"
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#include "stepper.h"
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#include "temperature.h"
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#include "ultralcd.h"
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//===========================================================================
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//=============================public variables ============================
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//===========================================================================
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unsigned long minsegmenttime;
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float max_feedrate[4]; // set the max speeds
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float axis_steps_per_unit[4];
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long max_acceleration_units_per_sq_second[4]; // Use M201 to override by software
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float minimumfeedrate;
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float acceleration; // Normal acceleration mm/s^2 THIS IS THE DEFAULT ACCELERATION for all moves. M204 SXXXX
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float retract_acceleration; // mm/s^2 filament pull-pack and push-forward while standing still in the other axis M204 TXXXX
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float max_xy_jerk; //speed than can be stopped at once, if i understand correctly.
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float max_z_jerk;
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float mintravelfeedrate;
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unsigned long axis_steps_per_sqr_second[NUM_AXIS];
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// The current position of the tool in absolute steps
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long position[4]; //rescaled from extern when axis_steps_per_unit are changed by gcode
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static float previous_speed[4]; // Speed of previous path line segment
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static float previous_nominal_speed; // Nominal speed of previous path line segment
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//===========================================================================
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//=============================private variables ============================
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//===========================================================================
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static block_t block_buffer[BLOCK_BUFFER_SIZE]; // A ring buffer for motion instfructions
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static volatile unsigned char block_buffer_head; // Index of the next block to be pushed
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static volatile unsigned char block_buffer_tail; // Index of the block to process now
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// Used for the frequency limit
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static unsigned char old_direction_bits = 0; // Old direction bits. Used for speed calculations
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static long x_segment_time[3]={0,0,0}; // Segment times (in us). Used for speed calculations
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static long y_segment_time[3]={0,0,0};
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// Returns the index of the next block in the ring buffer
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// NOTE: Removed modulo (%) operator, which uses an expensive divide and multiplication.
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static int8_t next_block_index(int8_t block_index) {
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block_index++;
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if (block_index == BLOCK_BUFFER_SIZE) { block_index = 0; }
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return(block_index);
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}
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// Returns the index of the previous block in the ring buffer
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static int8_t prev_block_index(int8_t block_index) {
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if (block_index == 0) { block_index = BLOCK_BUFFER_SIZE; }
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block_index--;
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return(block_index);
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}
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//===========================================================================
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//=============================functions ============================
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//===========================================================================
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// Calculates the distance (not time) it takes to accelerate from initial_rate to target_rate using the
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// given acceleration:
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inline float estimate_acceleration_distance(float initial_rate, float target_rate, float acceleration) {
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if (acceleration!=0) {
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return((target_rate*target_rate-initial_rate*initial_rate)/
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(2.0*acceleration));
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}
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else {
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return 0.0; // acceleration was 0, set acceleration distance to 0
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}
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}
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// This function gives you the point at which you must start braking (at the rate of -acceleration) if
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// you started at speed initial_rate and accelerated until this point and want to end at the final_rate after
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// a total travel of distance. This can be used to compute the intersection point between acceleration and
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// deceleration in the cases where the trapezoid has no plateau (i.e. never reaches maximum speed)
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inline float intersection_distance(float initial_rate, float final_rate, float acceleration, float distance) {
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if (acceleration!=0) {
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return((2.0*acceleration*distance-initial_rate*initial_rate+final_rate*final_rate)/
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(4.0*acceleration) );
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}
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else {
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return 0.0; // acceleration was 0, set intersection distance to 0
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}
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}
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// Calculates trapezoid parameters so that the entry- and exit-speed is compensated by the provided factors.
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void calculate_trapezoid_for_block(block_t *block, float entry_factor, float exit_factor) {
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long initial_rate = ceil(block->nominal_rate*entry_factor); // (step/min)
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long final_rate = ceil(block->nominal_rate*exit_factor); // (step/min)
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// Limit minimal step rate (Otherwise the timer will overflow.)
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if(initial_rate <120) {initial_rate=120; }
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if(final_rate < 120) {final_rate=120; }
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long acceleration = block->acceleration_st;
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int32_t accelerate_steps =
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ceil(estimate_acceleration_distance(block->initial_rate, block->nominal_rate, acceleration));
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int32_t decelerate_steps =
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floor(estimate_acceleration_distance(block->nominal_rate, block->final_rate, -acceleration));
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// Calculate the size of Plateau of Nominal Rate.
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int32_t plateau_steps = block->step_event_count-accelerate_steps-decelerate_steps;
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// Is the Plateau of Nominal Rate smaller than nothing? That means no cruising, and we will
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// have to use intersection_distance() to calculate when to abort acceleration and start braking
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// in order to reach the final_rate exactly at the end of this block.
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if (plateau_steps < 0) {
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accelerate_steps = ceil(
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intersection_distance(block->initial_rate, block->final_rate, acceleration, block->step_event_count));
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accelerate_steps = max(accelerate_steps,0); // Check limits due to numerical round-off
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accelerate_steps = min(accelerate_steps,block->step_event_count);
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plateau_steps = 0;
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}
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#ifdef ADVANCE
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long initial_advance = block->advance*entry_factor*entry_factor;
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long final_advance = block->advance*exit_factor*exit_factor;
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#endif // ADVANCE
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// block->accelerate_until = accelerate_steps;
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// block->decelerate_after = accelerate_steps+plateau_steps;
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CRITICAL_SECTION_START; // Fill variables used by the stepper in a critical section
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if(block->busy == false) { // Don't update variables if block is busy.
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block->accelerate_until = accelerate_steps;
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block->decelerate_after = accelerate_steps+plateau_steps;
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block->initial_rate = initial_rate;
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block->final_rate = final_rate;
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#ifdef ADVANCE
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block->initial_advance = initial_advance;
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block->final_advance = final_advance;
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#endif //ADVANCE
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}
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CRITICAL_SECTION_END;
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}
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// Calculates the maximum allowable speed at this point when you must be able to reach target_velocity using the
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// acceleration within the allotted distance.
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inline float max_allowable_speed(float acceleration, float target_velocity, float distance) {
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return sqrt(target_velocity*target_velocity-2*acceleration*distance);
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}
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// "Junction jerk" in this context is the immediate change in speed at the junction of two blocks.
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// This method will calculate the junction jerk as the euclidean distance between the nominal
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// velocities of the respective blocks.
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//inline float junction_jerk(block_t *before, block_t *after) {
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// return sqrt(
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// pow((before->speed_x-after->speed_x), 2)+pow((before->speed_y-after->speed_y), 2));
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//}
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// The kernel called by planner_recalculate() when scanning the plan from last to first entry.
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void planner_reverse_pass_kernel(block_t *previous, block_t *current, block_t *next) {
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if(!current) { return; }
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if (next) {
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// If entry speed is already at the maximum entry speed, no need to recheck. Block is cruising.
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// If not, block in state of acceleration or deceleration. Reset entry speed to maximum and
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// check for maximum allowable speed reductions to ensure maximum possible planned speed.
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if (current->entry_speed != current->max_entry_speed) {
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// If nominal length true, max junction speed is guaranteed to be reached. Only compute
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// for max allowable speed if block is decelerating and nominal length is false.
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if ((!current->nominal_length_flag) && (current->max_entry_speed > next->entry_speed)) {
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current->entry_speed = min( current->max_entry_speed,
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max_allowable_speed(-current->acceleration,next->entry_speed,current->millimeters));
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} else {
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current->entry_speed = current->max_entry_speed;
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}
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current->recalculate_flag = true;
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}
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} // Skip last block. Already initialized and set for recalculation.
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}
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// planner_recalculate() needs to go over the current plan twice. Once in reverse and once forward. This
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// implements the reverse pass.
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void planner_reverse_pass() {
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char block_index = block_buffer_head;
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if(((block_buffer_head-block_buffer_tail + BLOCK_BUFFER_SIZE) & (BLOCK_BUFFER_SIZE - 1)) > 3) {
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block_index = (block_buffer_head - 3) & (BLOCK_BUFFER_SIZE - 1);
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block_t *block[3] = { NULL, NULL, NULL };
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while(block_index != block_buffer_tail) {
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block_index = prev_block_index(block_index);
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block[2]= block[1];
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block[1]= block[0];
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block[0] = &block_buffer[block_index];
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planner_reverse_pass_kernel(block[0], block[1], block[2]);
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}
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}
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}
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// The kernel called by planner_recalculate() when scanning the plan from first to last entry.
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void planner_forward_pass_kernel(block_t *previous, block_t *current, block_t *next) {
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if(!previous) { return; }
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// If the previous block is an acceleration block, but it is not long enough to complete the
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// full speed change within the block, we need to adjust the entry speed accordingly. Entry
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// speeds have already been reset, maximized, and reverse planned by reverse planner.
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// If nominal length is true, max junction speed is guaranteed to be reached. No need to recheck.
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if (!previous->nominal_length_flag) {
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if (previous->entry_speed < current->entry_speed) {
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double entry_speed = min( current->entry_speed,
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max_allowable_speed(-previous->acceleration,previous->entry_speed,previous->millimeters) );
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// Check for junction speed change
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if (current->entry_speed != entry_speed) {
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current->entry_speed = entry_speed;
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current->recalculate_flag = true;
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}
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}
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}
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}
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// planner_recalculate() needs to go over the current plan twice. Once in reverse and once forward. This
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// implements the forward pass.
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void planner_forward_pass() {
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char block_index = block_buffer_tail;
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block_t *block[3] = { NULL, NULL, NULL };
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while(block_index != block_buffer_head) {
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block[0] = block[1];
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block[1] = block[2];
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block[2] = &block_buffer[block_index];
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planner_forward_pass_kernel(block[0],block[1],block[2]);
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block_index = next_block_index(block_index);
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}
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planner_forward_pass_kernel(block[1], block[2], NULL);
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}
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// Recalculates the trapezoid speed profiles for all blocks in the plan according to the
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// entry_factor for each junction. Must be called by planner_recalculate() after
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// updating the blocks.
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void planner_recalculate_trapezoids() {
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int8_t block_index = block_buffer_tail;
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block_t *current;
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block_t *next = NULL;
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while(block_index != block_buffer_head) {
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current = next;
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next = &block_buffer[block_index];
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if (current) {
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// Recalculate if current block entry or exit junction speed has changed.
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if (current->recalculate_flag || next->recalculate_flag) {
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// NOTE: Entry and exit factors always > 0 by all previous logic operations.
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calculate_trapezoid_for_block(current, current->entry_speed/current->nominal_speed,
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next->entry_speed/current->nominal_speed);
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current->recalculate_flag = false; // Reset current only to ensure next trapezoid is computed
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}
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}
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block_index = next_block_index( block_index );
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}
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// Last/newest block in buffer. Exit speed is set with MINIMUM_PLANNER_SPEED. Always recalculated.
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if(next != NULL) {
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calculate_trapezoid_for_block(next, next->entry_speed/next->nominal_speed,
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MINIMUM_PLANNER_SPEED/next->nominal_speed);
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next->recalculate_flag = false;
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}
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}
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// Recalculates the motion plan according to the following algorithm:
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//
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// 1. Go over every block in reverse order and calculate a junction speed reduction (i.e. block_t.entry_factor)
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// so that:
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// a. The junction jerk is within the set limit
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// b. No speed reduction within one block requires faster deceleration than the one, true constant
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// acceleration.
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// 2. Go over every block in chronological order and dial down junction speed reduction values if
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// a. The speed increase within one block would require faster accelleration than the one, true
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// constant acceleration.
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//
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// When these stages are complete all blocks have an entry_factor that will allow all speed changes to
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// be performed using only the one, true constant acceleration, and where no junction jerk is jerkier than
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// the set limit. Finally it will:
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//
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// 3. Recalculate trapezoids for all blocks.
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void planner_recalculate() {
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planner_reverse_pass();
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planner_forward_pass();
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planner_recalculate_trapezoids();
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}
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void plan_init() {
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block_buffer_head = 0;
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block_buffer_tail = 0;
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memset(position, 0, sizeof(position)); // clear position
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previous_speed[0] = 0.0;
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previous_speed[1] = 0.0;
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previous_speed[2] = 0.0;
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previous_speed[3] = 0.0;
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previous_nominal_speed = 0.0;
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}
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void plan_discard_current_block() {
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if (block_buffer_head != block_buffer_tail) {
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block_buffer_tail = (block_buffer_tail + 1) & (BLOCK_BUFFER_SIZE - 1);
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}
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}
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block_t *plan_get_current_block() {
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if (block_buffer_head == block_buffer_tail) {
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return(NULL);
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}
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block_t *block = &block_buffer[block_buffer_tail];
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block->busy = true;
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return(block);
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}
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void check_axes_activity() {
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unsigned char x_active = 0;
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unsigned char y_active = 0;
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unsigned char z_active = 0;
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unsigned char e_active = 0;
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block_t *block;
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if(block_buffer_tail != block_buffer_head) {
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char block_index = block_buffer_tail;
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while(block_index != block_buffer_head) {
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block = &block_buffer[block_index];
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if(block->steps_x != 0) x_active++;
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if(block->steps_y != 0) y_active++;
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if(block->steps_z != 0) z_active++;
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if(block->steps_e != 0) e_active++;
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block_index = (block_index+1) & (BLOCK_BUFFER_SIZE - 1);
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}
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}
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if((DISABLE_X) && (x_active == 0)) disable_x();
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if((DISABLE_Y) && (y_active == 0)) disable_y();
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if((DISABLE_Z) && (z_active == 0)) disable_z();
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if((DISABLE_E) && (e_active == 0)) disable_e();
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}
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float junction_deviation = 0.1;
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// Add a new linear movement to the buffer. steps_x, _y and _z is the absolute position in
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// mm. Microseconds specify how many microseconds the move should take to perform. To aid acceleration
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// calculation the caller must also provide the physical length of the line in millimeters.
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void plan_buffer_line(const float &x, const float &y, const float &z, const float &e, float feed_rate)
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{
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// Calculate the buffer head after we push this byte
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int next_buffer_head = next_block_index(block_buffer_head);
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// If the buffer is full: good! That means we are well ahead of the robot.
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// Rest here until there is room in the buffer.
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while(block_buffer_tail == next_buffer_head) {
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manage_heater();
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manage_inactivity(1);
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LCD_STATUS;
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}
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// The target position of the tool in absolute steps
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// Calculate target position in absolute steps
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//this should be done after the wait, because otherwise a M92 code within the gcode disrupts this calculation somehow
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long target[4];
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target[X_AXIS] = lround(x*axis_steps_per_unit[X_AXIS]);
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target[Y_AXIS] = lround(y*axis_steps_per_unit[Y_AXIS]);
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target[Z_AXIS] = lround(z*axis_steps_per_unit[Z_AXIS]);
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target[E_AXIS] = lround(e*axis_steps_per_unit[E_AXIS]);
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// Prepare to set up new block
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block_t *block = &block_buffer[block_buffer_head];
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// Mark block as not busy (Not executed by the stepper interrupt)
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block->busy = false;
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// Number of steps for each axis
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block->steps_x = labs(target[X_AXIS]-position[X_AXIS]);
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block->steps_y = labs(target[Y_AXIS]-position[Y_AXIS]);
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block->steps_z = labs(target[Z_AXIS]-position[Z_AXIS]);
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block->steps_e = labs(target[E_AXIS]-position[E_AXIS]);
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block->step_event_count = max(block->steps_x, max(block->steps_y, max(block->steps_z, block->steps_e)));
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// Bail if this is a zero-length block
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if (block->step_event_count <=dropsegments) { return; };
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// Compute direction bits for this block
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block->direction_bits = 0;
|
|
if (target[X_AXIS] < position[X_AXIS]) { block->direction_bits |= (1<<X_AXIS); }
|
|
if (target[Y_AXIS] < position[Y_AXIS]) { block->direction_bits |= (1<<Y_AXIS); }
|
|
if (target[Z_AXIS] < position[Z_AXIS]) { block->direction_bits |= (1<<Z_AXIS); }
|
|
if (target[E_AXIS] < position[E_AXIS]) { block->direction_bits |= (1<<E_AXIS); }
|
|
|
|
//enable active axes
|
|
if(block->steps_x != 0) enable_x();
|
|
if(block->steps_y != 0) enable_y();
|
|
if(block->steps_z != 0) enable_z();
|
|
if(block->steps_e != 0) enable_e();
|
|
|
|
float delta_mm[4];
|
|
delta_mm[X_AXIS] = (target[X_AXIS]-position[X_AXIS])/axis_steps_per_unit[X_AXIS];
|
|
delta_mm[Y_AXIS] = (target[Y_AXIS]-position[Y_AXIS])/axis_steps_per_unit[Y_AXIS];
|
|
delta_mm[Z_AXIS] = (target[Z_AXIS]-position[Z_AXIS])/axis_steps_per_unit[Z_AXIS];
|
|
delta_mm[E_AXIS] = (target[E_AXIS]-position[E_AXIS])/axis_steps_per_unit[E_AXIS];
|
|
block->millimeters = sqrt(square(delta_mm[X_AXIS]) + square(delta_mm[Y_AXIS]) +
|
|
square(delta_mm[Z_AXIS]));
|
|
float inverse_millimeters = 1.0/block->millimeters; // Inverse millimeters to remove multiple divides
|
|
|
|
// Calculate speed in mm/second for each axis. No divide by zero due to previous checks.
|
|
float inverse_second = feed_rate * inverse_millimeters;
|
|
|
|
block->nominal_speed = block->millimeters * inverse_second; // (mm/sec) Always > 0
|
|
block->nominal_rate = ceil(block->step_event_count * inverse_second); // (step/sec) Always > 0
|
|
|
|
// unsigned long microseconds;
|
|
#if 0
|
|
if (block->steps_e == 0) {
|
|
if(feed_rate<mintravelfeedrate) feed_rate=mintravelfeedrate;
|
|
}
|
|
else {
|
|
if(feed_rate<minimumfeedrate) feed_rate=minimumfeedrate;
|
|
}
|
|
|
|
microseconds = lround((block->millimeters/feed_rate)*1000000);
|
|
|
|
// slow down when de buffer starts to empty, rather than wait at the corner for a buffer refill
|
|
// reduces/removes corner blobs as the machine won't come to a full stop.
|
|
int blockcount=(block_buffer_head-block_buffer_tail + BLOCK_BUFFER_SIZE) & (BLOCK_BUFFER_SIZE - 1);
|
|
|
|
if ((blockcount>0) && (blockcount < (BLOCK_BUFFER_SIZE - 4))) {
|
|
if (microseconds<minsegmenttime) { // buffer is draining, add extra time. The amount of time added increases if the buffer is still emptied more.
|
|
microseconds=microseconds+lround(2*(minsegmenttime-microseconds)/blockcount);
|
|
}
|
|
}
|
|
else {
|
|
if (microseconds<minsegmenttime) microseconds=minsegmenttime;
|
|
}
|
|
// END OF SLOW DOWN SECTION
|
|
#endif
|
|
|
|
// Calculate speed in mm/sec for each axis
|
|
float current_speed[4];
|
|
for(int i=0; i < 4; i++) {
|
|
current_speed[i] = delta_mm[i] * inverse_second;
|
|
}
|
|
|
|
// Limit speed per axis
|
|
float speed_factor = 1.0; //factor <=1 do decrease speed
|
|
for(int i=0; i < 4; i++) {
|
|
if(abs(current_speed[i]) > max_feedrate[i])
|
|
speed_factor = min(speed_factor, max_feedrate[i] / abs(current_speed[i]));
|
|
}
|
|
|
|
// Max segement time in us.
|
|
|
|
#ifdef XY_FREQUENCY_LIMIT
|
|
#define MAX_FREQ_TIME (1000000.0/XY_FREQUENCY_LIMIT)
|
|
|
|
// Check and limit the xy direction change frequency
|
|
unsigned char direction_change = block->direction_bits ^ old_direction_bits;
|
|
old_direction_bits = block->direction_bits;
|
|
long segment_time = lround(1000000.0/inverse_second);
|
|
if((direction_change & (1<<X_AXIS)) == 0) {
|
|
x_segment_time[0] += segment_time;
|
|
}
|
|
else {
|
|
x_segment_time[2] = x_segment_time[1];
|
|
x_segment_time[1] = x_segment_time[0];
|
|
x_segment_time[0] = segment_time;
|
|
}
|
|
if((direction_change & (1<<Y_AXIS)) == 0) {
|
|
y_segment_time[0] += segment_time;
|
|
}
|
|
else {
|
|
y_segment_time[2] = y_segment_time[1];
|
|
y_segment_time[1] = y_segment_time[0];
|
|
y_segment_time[0] = segment_time;
|
|
}
|
|
long max_x_segment_time = max(x_segment_time[0], max(x_segment_time[1], x_segment_time[2]));
|
|
long max_y_segment_time = max(y_segment_time[0], max(y_segment_time[1], y_segment_time[2]));
|
|
long min_xy_segment_time =min(max_x_segment_time, max_y_segment_time);
|
|
if(min_xy_segment_time < MAX_FREQ_TIME) speed_factor = min(speed_factor, (float)min_xy_segment_time / (float)MAX_FREQ_TIME);
|
|
#endif
|
|
|
|
|
|
// Correct the speed
|
|
if( speed_factor < 1.0) {
|
|
// Serial.print("speed factor : "); Serial.println(speed_factor);
|
|
for(int i=0; i < 4; i++) {
|
|
if(abs(current_speed[i]) > max_feedrate[i])
|
|
speed_factor = min(speed_factor, max_feedrate[i] / abs(current_speed[i]));
|
|
// Serial.print("current_speed"); Serial.print(i); Serial.print(" : "); Serial.println(current_speed[i]);
|
|
}
|
|
for(unsigned char i=0; i < 4; i++) {
|
|
current_speed[i] *= speed_factor;
|
|
}
|
|
block->nominal_speed *= speed_factor;
|
|
block->nominal_rate *= speed_factor;
|
|
}
|
|
|
|
// Compute and limit the acceleration rate for the trapezoid generator.
|
|
float steps_per_mm = block->step_event_count/block->millimeters;
|
|
if(block->steps_x == 0 && block->steps_y == 0 && block->steps_z == 0) {
|
|
block->acceleration_st = ceil(retract_acceleration * steps_per_mm); // convert to: acceleration steps/sec^2
|
|
}
|
|
else {
|
|
block->acceleration_st = ceil(acceleration * steps_per_mm); // convert to: acceleration steps/sec^2
|
|
// Limit acceleration per axis
|
|
if(((float)block->acceleration_st * (float)block->steps_x / (float)block->step_event_count) > axis_steps_per_sqr_second[X_AXIS])
|
|
block->acceleration_st = axis_steps_per_sqr_second[X_AXIS];
|
|
if(((float)block->acceleration_st * (float)block->steps_y / (float)block->step_event_count) > axis_steps_per_sqr_second[Y_AXIS])
|
|
block->acceleration_st = axis_steps_per_sqr_second[Y_AXIS];
|
|
if(((float)block->acceleration_st * (float)block->steps_e / (float)block->step_event_count) > axis_steps_per_sqr_second[E_AXIS])
|
|
block->acceleration_st = axis_steps_per_sqr_second[E_AXIS];
|
|
if(((float)block->acceleration_st * (float)block->steps_z / (float)block->step_event_count ) > axis_steps_per_sqr_second[Z_AXIS])
|
|
block->acceleration_st = axis_steps_per_sqr_second[Z_AXIS];
|
|
}
|
|
block->acceleration = block->acceleration_st / steps_per_mm;
|
|
block->acceleration_rate = (long)((float)block->acceleration_st * 8.388608);
|
|
|
|
#if 0 // Use old jerk for now
|
|
// Compute path unit vector
|
|
double unit_vec[3];
|
|
|
|
unit_vec[X_AXIS] = delta_mm[X_AXIS]*inverse_millimeters;
|
|
unit_vec[Y_AXIS] = delta_mm[Y_AXIS]*inverse_millimeters;
|
|
unit_vec[Z_AXIS] = delta_mm[Z_AXIS]*inverse_millimeters;
|
|
|
|
// Compute maximum allowable entry speed at junction by centripetal acceleration approximation.
|
|
// Let a circle be tangent to both previous and current path line segments, where the junction
|
|
// deviation is defined as the distance from the junction to the closest edge of the circle,
|
|
// colinear with the circle center. The circular segment joining the two paths represents the
|
|
// path of centripetal acceleration. Solve for max velocity based on max acceleration about the
|
|
// radius of the circle, defined indirectly by junction deviation. This may be also viewed as
|
|
// path width or max_jerk in the previous grbl version. This approach does not actually deviate
|
|
// from path, but used as a robust way to compute cornering speeds, as it takes into account the
|
|
// nonlinearities of both the junction angle and junction velocity.
|
|
double vmax_junction = MINIMUM_PLANNER_SPEED; // Set default max junction speed
|
|
|
|
// Skip first block or when previous_nominal_speed is used as a flag for homing and offset cycles.
|
|
if ((block_buffer_head != block_buffer_tail) && (previous_nominal_speed > 0.0)) {
|
|
// Compute cosine of angle between previous and current path. (prev_unit_vec is negative)
|
|
// NOTE: Max junction velocity is computed without sin() or acos() by trig half angle identity.
|
|
double cos_theta = - previous_unit_vec[X_AXIS] * unit_vec[X_AXIS]
|
|
- previous_unit_vec[Y_AXIS] * unit_vec[Y_AXIS]
|
|
- previous_unit_vec[Z_AXIS] * unit_vec[Z_AXIS] ;
|
|
|
|
// Skip and use default max junction speed for 0 degree acute junction.
|
|
if (cos_theta < 0.95) {
|
|
vmax_junction = min(previous_nominal_speed,block->nominal_speed);
|
|
// Skip and avoid divide by zero for straight junctions at 180 degrees. Limit to min() of nominal speeds.
|
|
if (cos_theta > -0.95) {
|
|
// Compute maximum junction velocity based on maximum acceleration and junction deviation
|
|
double sin_theta_d2 = sqrt(0.5*(1.0-cos_theta)); // Trig half angle identity. Always positive.
|
|
vmax_junction = min(vmax_junction,
|
|
sqrt(block->acceleration * junction_deviation * sin_theta_d2/(1.0-sin_theta_d2)) );
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
// Start with a safe speed
|
|
float vmax_junction = max_xy_jerk/2;
|
|
if(abs(current_speed[Z_AXIS]) > max_z_jerk/2)
|
|
vmax_junction = max_z_jerk/2;
|
|
vmax_junction = min(vmax_junction, block->nominal_speed);
|
|
|
|
if ((block_buffer_head != block_buffer_tail) && (previous_nominal_speed > 0.0)) {
|
|
float jerk = sqrt(pow((current_speed[X_AXIS]-previous_speed[X_AXIS]), 2)+pow((current_speed[Y_AXIS]-previous_speed[Y_AXIS]), 2));
|
|
if((previous_speed[X_AXIS] != 0.0) || (previous_speed[Y_AXIS] != 0.0)) {
|
|
vmax_junction = block->nominal_speed;
|
|
}
|
|
if (jerk > max_xy_jerk) {
|
|
vmax_junction *= (max_xy_jerk/jerk);
|
|
}
|
|
if(abs(current_speed[Z_AXIS] - previous_speed[Z_AXIS]) > max_z_jerk) {
|
|
vmax_junction *= (max_z_jerk/abs(current_speed[Z_AXIS] - previous_speed[Z_AXIS]));
|
|
}
|
|
}
|
|
block->max_entry_speed = vmax_junction;
|
|
|
|
// Initialize block entry speed. Compute based on deceleration to user-defined MINIMUM_PLANNER_SPEED.
|
|
double v_allowable = max_allowable_speed(-block->acceleration,MINIMUM_PLANNER_SPEED,block->millimeters);
|
|
block->entry_speed = min(vmax_junction, v_allowable);
|
|
|
|
// Initialize planner efficiency flags
|
|
// Set flag if block will always reach maximum junction speed regardless of entry/exit speeds.
|
|
// If a block can de/ac-celerate from nominal speed to zero within the length of the block, then
|
|
// the current block and next block junction speeds are guaranteed to always be at their maximum
|
|
// junction speeds in deceleration and acceleration, respectively. This is due to how the current
|
|
// block nominal speed limits both the current and next maximum junction speeds. Hence, in both
|
|
// the reverse and forward planners, the corresponding block junction speed will always be at the
|
|
// the maximum junction speed and may always be ignored for any speed reduction checks.
|
|
if (block->nominal_speed <= v_allowable) { block->nominal_length_flag = true; }
|
|
else { block->nominal_length_flag = false; }
|
|
block->recalculate_flag = true; // Always calculate trapezoid for new block
|
|
|
|
// Update previous path unit_vector and nominal speed
|
|
memcpy(previous_speed, current_speed, sizeof(previous_speed)); // previous_speed[] = current_speed[]
|
|
previous_nominal_speed = block->nominal_speed;
|
|
|
|
#ifdef ADVANCE
|
|
// Calculate advance rate
|
|
if((block->steps_e == 0) || (block->steps_x == 0 && block->steps_y == 0 && block->steps_z == 0)) {
|
|
block->advance_rate = 0;
|
|
block->advance = 0;
|
|
}
|
|
else {
|
|
long acc_dist = estimate_acceleration_distance(0, block->nominal_rate, block->acceleration_st);
|
|
float advance = (STEPS_PER_CUBIC_MM_E * EXTRUDER_ADVANCE_K) *
|
|
(block->speed_e * block->speed_e * EXTRUTION_AREA * EXTRUTION_AREA / 3600.0)*65536;
|
|
block->advance = advance;
|
|
if(acc_dist == 0) {
|
|
block->advance_rate = 0;
|
|
}
|
|
else {
|
|
block->advance_rate = advance / (float)acc_dist;
|
|
}
|
|
}
|
|
#endif // ADVANCE
|
|
|
|
|
|
|
|
|
|
calculate_trapezoid_for_block(block, block->entry_speed/block->nominal_speed,
|
|
MINIMUM_PLANNER_SPEED/block->nominal_speed);
|
|
|
|
// Move buffer head
|
|
block_buffer_head = next_buffer_head;
|
|
|
|
// Update position
|
|
memcpy(position, target, sizeof(target)); // position[] = target[]
|
|
|
|
planner_recalculate();
|
|
|
|
st_wake_up();
|
|
}
|
|
|
|
void plan_set_position(const float &x, const float &y, const float &z, const float &e)
|
|
{
|
|
position[X_AXIS] = lround(x*axis_steps_per_unit[X_AXIS]);
|
|
position[Y_AXIS] = lround(y*axis_steps_per_unit[Y_AXIS]);
|
|
position[Z_AXIS] = lround(z*axis_steps_per_unit[Z_AXIS]);
|
|
position[E_AXIS] = lround(e*axis_steps_per_unit[E_AXIS]);
|
|
previous_nominal_speed = 0.0; // Resets planner junction speeds. Assumes start from rest.
|
|
previous_speed[0] = 0.0;
|
|
previous_speed[1] = 0.0;
|
|
previous_speed[2] = 0.0;
|
|
previous_speed[3] = 0.0;
|
|
}
|
|
|