src/modules/robot/Block.cpp

   1 /*
   2       This file is part of Smoothie (http://smoothieware.org/). The motion control part is heavily based on Grbl (https://github.com/simen/grbl).
   3       Smoothie is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
   4       Smoothie is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
   5       You should have received a copy of the GNU General Public License along with Smoothie. If not, see <http://www.gnu.org/licenses/>.
   6 */
   7
   8 #include "libs/Module.h"
   9 #include "libs/Kernel.h"
  10 #include "libs/nuts_bolts.h"
  11 #include <math.h>
  12 #include <string>
  13 #include "Block.h"
  14 #include "Planner.h"
  15 #include "Conveyor.h"
  16 using std::string;
  17 #include <vector>
  18 #include "../communication/utils/Gcode.h"
  19
  20 Block::Block(){
  21     clear_vector(this->steps);
  22     this->times_taken = 0;   // A block can be "taken" by any number of modules, and the next block is not moved to until all the modules have "released" it. This value serves as a tracker.
  23     this->is_ready = false;
  24     this->initial_rate = -1;
  25     this->final_rate = -1;
  26 }
  27
  28 void Block::debug(Kernel* kernel){
  29     kernel->streams->printf("%p: steps:%4d|%4d|%4d(max:%4d) nominal:r%10d/s%6.1f mm:%9.6f rdelta:%8f acc:%5d dec:%5d rates:%10d>%10d taken:%d ready:%d \r\n", this, this->steps[0], this->steps[1], this->steps[2], this->steps_event_count, this->nominal_rate, this->nominal_speed, this->millimeters, this->rate_delta, this->accelerate_until, this->decelerate_after, this->initial_rate, this->final_rate, this->times_taken, this->is_ready );
  30 }
  31
  32
  33 /* Calculates trapezoid parameters so that the entry- and exit-speed is compensated by the provided factors.
  34 // The factors represent a factor of braking and must be in the range 0.0-1.0.
  35 //                                +--------+ <- nominal_rate
  36 //                               /          \
  37 // nominal_rate*entry_factor -> +            \
  38 //                              |             + <- nominal_rate*exit_factor
  39 //                              +-------------+
  40 //                                  time -->
  41 //*/
  42 void Block::calculate_trapezoid( double entryfactor, double exitfactor ){
  43
  44     //this->conveyor->kernel->streams->printf("%p calculating trapezoid\r\n", this);
  45
  46     this->initial_rate = ceil(this->nominal_rate * entryfactor);   // (step/min)
  47     this->final_rate   = ceil(this->nominal_rate * exitfactor);    // (step/min)
  48
  49     //this->conveyor->kernel->streams->printf("initrate:%f finalrate:%f\r\n", this->initial_rate, this->final_rate);
  50
  51     double acceleration_per_minute = this->rate_delta * this->planner->kernel->stepper->acceleration_ticks_per_second * 60.0; // ( step/min^2)
  52     int accelerate_steps = ceil( this->estimate_acceleration_distance( this->initial_rate, this->nominal_rate, acceleration_per_minute ) );
  53     int decelerate_steps = floor( this->estimate_acceleration_distance( this->nominal_rate, this->final_rate,  -acceleration_per_minute ) );
  54
  55
  56     // Calculate the size of Plateau of Nominal Rate.
  57     int plateau_steps = this->steps_event_count-accelerate_steps-decelerate_steps;
  58
  59     //this->conveyor->kernel->streams->printf("accelperminute:%f accelerate_steps:%d decelerate_steps:%d plateau:%d \r\n", acceleration_per_minute, accelerate_steps, decelerate_steps, plateau_steps );
  60
  61    // Is the Plateau of Nominal Rate smaller than nothing? That means no cruising, and we will
  62    // have to use intersection_distance() to calculate when to abort acceleration and start braking
  63    // in order to reach the final_rate exactly at the end of this block.
  64    if (plateau_steps < 0) {
  65        accelerate_steps = ceil(this->intersection_distance(this->initial_rate, this->final_rate, acceleration_per_minute, this->steps_event_count));
  66        accelerate_steps = max( accelerate_steps, 0 ); // Check limits due to numerical round-off
  67        accelerate_steps = min( accelerate_steps, int(this->steps_event_count) );
  68        plateau_steps = 0;
  69    }
  70
  71    this->accelerate_until = accelerate_steps;
  72    this->decelerate_after = accelerate_steps+plateau_steps;
  73
  74    //this->debug(this->conveyor->kernel);
  75
  76    /*
  77    // TODO: FIX THIS: DIRTY HACK so that we don't end too early for blocks with 0 as final_rate. Doing the math right would be better. Probably fixed in latest grbl
  78    if( this->final_rate < 0.01 ){
  79         this->decelerate_after += floor( this->nominal_rate / 60 / this->planner->kernel->stepper->acceleration_ticks_per_second ) * 3;
  80     }
  81     */
  82 }
  83
  84 // Calculates the distance (not time) it takes to accelerate from initial_rate to target_rate using the
  85 // given acceleration:
  86 double Block::estimate_acceleration_distance(double initialrate, double targetrate, double acceleration) {
  87       return( ((targetrate*targetrate)-(initialrate*initialrate))/(2L*acceleration));
  88 }
  89
  90 // This function gives you the point at which you must start braking (at the rate of -acceleration) if
  91 // you started at speed initial_rate and accelerated until this point and want to end at the final_rate after
  92 // a total travel of distance. This can be used to compute the intersection point between acceleration and
  93 // deceleration in the cases where the trapezoid has no plateau (i.e. never reaches maximum speed)
  94 //
  95 /*                          + <- some maximum rate we don't care about
  96                            /|\
  97                           / | \
  98                          /  |  + <- final_rate
  99                         /   |  |
 100        initial_rate -> +----+--+
 101                             ^ ^
 102                             | |
 103         intersection_distance distance */
 104 double Block::intersection_distance(double initialrate, double finalrate, double acceleration, double distance) {
 105    return((2*acceleration*distance-initialrate*initialrate+finalrate*finalrate)/(4*acceleration));
 106 }
 107
 108 // Calculates the maximum allowable speed at this point when you must be able to reach target_velocity using the
 109 // acceleration within the allotted distance.
 110 inline double max_allowable_speed(double acceleration, double target_velocity, double distance) {
 111   return(
 112     sqrt(target_velocity*target_velocity-2L*acceleration*distance)  //Was acceleration*60*60*distance, in case this breaks, but here we prefer to use seconds instead of minutes
 113   );
 114 }
 115
 116
 117 // Called by Planner::recalculate() when scanning the plan from last to first entry.
 118 void Block::reverse_pass(Block* next, Block* previous){
 119
 120     if (next) {
 121         // If entry speed is already at the maximum entry speed, no need to recheck. Block is cruising.
 122         // If not, block in state of acceleration or deceleration. Reset entry speed to maximum and
 123         // check for maximum allowable speed reductions to ensure maximum possible planned speed.
 124         if (this->entry_speed != this->max_entry_speed) {
 125
 126             // If nominal length true, max junction speed is guaranteed to be reached. Only compute
 127             // for max allowable speed if block is decelerating and nominal length is false.
 128             if ((!this->nominal_length_flag) && (this->max_entry_speed > next->entry_speed)) {
 129                 this->entry_speed = min( this->max_entry_speed, max_allowable_speed(-this->planner->acceleration,next->entry_speed,this->millimeters));
 130             } else {
 131                 this->entry_speed = this->max_entry_speed;
 132             }
 133             this->recalculate_flag = true;
 134
 135         }
 136     } // Skip last block. Already initialized and set for recalculation.
 137
 138 }
 139
 140
 141 // Called by Planner::recalculate() when scanning the plan from first to last entry.
 142 void Block::forward_pass(Block* previous, Block* next){
 143
 144     if(!previous) { return; } // Begin planning after buffer_tail
 145
 146     // If the previous block is an acceleration block, but it is not long enough to complete the
 147     // full speed change within the block, we need to adjust the entry speed accordingly. Entry
 148     // speeds have already been reset, maximized, and reverse planned by reverse planner.
 149     // If nominal length is true, max junction speed is guaranteed to be reached. No need to recheck.
 150     if (!previous->nominal_length_flag) {
 151         if (previous->entry_speed < this->entry_speed) {
 152           double entry_speed = min( this->entry_speed,
 153             max_allowable_speed(-this->planner->acceleration,previous->entry_speed,previous->millimeters) );
 154
 155           // Check for junction speed change
 156           if (this->entry_speed != entry_speed) {
 157             this->entry_speed = entry_speed;
 158             this->recalculate_flag = true;
 159           }
 160         }
 161     }
 162
 163 }
 164
 165
 166 // Gcodes are attached to their respective blocks so that on_gcode_execute can be called with it
 167 void Block::append_gcode(Gcode* gcode){
 168    __disable_irq();
 169    Gcode new_gcode = *gcode;
 170    this->gcodes.push_back(new_gcode);
 171    __enable_irq();
 172 }
 173
 174 // The attached gcodes are then poped and the on_gcode_execute event is called with them as a parameter
 175 void Block::pop_and_execute_gcode(Kernel* &kernel){
 176     Block* block = const_cast<Block*>(this);
 177     for(unsigned short index=0; index<block->gcodes.size(); index++){
 178         //printf("GCODE Z: %s \r\n", block->gcodes[index].command.c_str() );
 179         kernel->call_event(ON_GCODE_EXECUTE, &(block->gcodes[index]));
 180     }
 181 }
 182
 183 // Signal the conveyor that this block is ready to be injected into the system
 184 void Block::ready(){
 185     this->is_ready = true;
 186     this->conveyor->new_block_added();
 187 }
 188
 189 // Mark the block as taken by one more module
 190 void Block::take(){
 191     this->times_taken++;
 192     //printf("taking %p times now:%d\r\n", this, int(this->times_taken) );
 193 }
 194
 195 // Mark the block as no longer taken by one module, go to next block if this free's it
 196 void Block::release(){
 197     //printf("release %p \r\n", this );
 198     this->times_taken--;
 199     //printf("releasing %p times now:%d\r\n", this, int(this->times_taken) );
 200     if( this->times_taken < 1 ){
 201         this->conveyor->kernel->call_event(ON_BLOCK_END, this);
 202         this->pop_and_execute_gcode(this->conveyor->kernel);
 203         Conveyor* conveyor = this->conveyor;
 204
 205         if( conveyor->queue.size() > conveyor->flush_blocks ){
 206             conveyor->flush_blocks++;
 207         }
 208
 209         if( conveyor->looking_for_new_block == false ){
 210             if( conveyor->queue.size() > conveyor->flush_blocks ){
 211                 Block* candidate =  conveyor->queue.get_ref(conveyor->flush_blocks);
 212                 if( candidate->is_ready ){
 213                     conveyor->current_block = candidate;
 214                     conveyor->kernel->call_event(ON_BLOCK_BEGIN, conveyor->current_block);
 215                     if( conveyor->current_block->times_taken < 1 ){
 216                         conveyor->current_block->times_taken = 1;
 217                         conveyor->current_block->release();
 218                     }
 219                 }else{
 220
 221                     conveyor->current_block = NULL;
 222
 223                 }
 224             }else{
 225                 conveyor->current_block = NULL;
 226             }
 227         }
 228     }
 229 }
 230
 231
 232