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 "mbed.h"
  13 #include <string>
  14 #include "Block.h"
  15 #include "Planner.h"
  16 #include "Player.h"
  17 using std::string;
  18 #include <vector>
  19 #include "../communication/utils/Gcode.h"
  20
  21 Block::Block(){
  22     clear_vector(this->steps);
  23     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.
  24     this->is_ready = false;
  25     this->initial_rate = -1;
  26     this->final_rate = -1;
  27 }
  28
  29 void Block::debug(Kernel* kernel){
  30     kernel->serial->printf("%p: steps:%4d|%4d|%4d(max:%4d) nominal:r%10d/s%6.1f mm:%9.6f rdelta:%8d 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 );
  31 }
  32
  33
  34 // Calculate a braking factor to reach baseline speed which is max_jerk/2, e.g. the
  35 // speed under which you cannot exceed max_jerk no matter what you do.
  36 double Block::compute_factor_for_safe_speed(){
  37     return( this->planner->max_jerk / this->nominal_speed );
  38 }
  39
  40
  41 // Calculates trapezoid parameters so that the entry- and exit-speed is compensated by the provided factors.
  42 // The factors represent a factor of braking and must be in the range 0.0-1.0.
  43 //                                +--------+ <- nominal_rate
  44 //                               /          \
  45 // nominal_rate*entry_factor -> +            \
  46 //                              |             + <- nominal_rate*exit_factor
  47 //                              +-------------+
  48 //                                  time -->
  49 void Block::calculate_trapezoid( double entryfactor, double exitfactor ){
  50
  51     this->initial_rate = ceil(this->nominal_rate * entryfactor);   // (step/min)
  52     this->final_rate   = ceil(this->nominal_rate * exitfactor);    // (step/min)
  53     //this->player->kernel->serial->printf("%p: r:%d \r\n", this, this->initial_rate);
  54     double acceleration_per_minute = this->rate_delta * this->planner->kernel->stepper->acceleration_ticks_per_second * 60.0;
  55     int accelerate_steps = ceil( this->estimate_acceleration_distance( this->initial_rate, this->nominal_rate, acceleration_per_minute ) );
  56     int decelerate_steps = ceil( this->estimate_acceleration_distance( this->nominal_rate, this->final_rate,  -acceleration_per_minute ) );
  57
  58     // Calculate the size of Plateau of Nominal Rate.
  59     int plateau_steps = this->steps_event_count-accelerate_steps-decelerate_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    // 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
  75    if( this->final_rate < 0.01 ){
  76         this->decelerate_after += floor( this->nominal_rate / 60 / this->planner->kernel->stepper->acceleration_ticks_per_second ) * 3;
  77     }
  78
  79 }
  80
  81 // Calculates the distance (not time) it takes to accelerate from initial_rate to target_rate using the
  82 // given acceleration:
  83 double Block::estimate_acceleration_distance(double initialrate, double targetrate, double acceleration) {
  84       return( (targetrate*targetrate-initialrate*initialrate)/(2L*acceleration));
  85 }
  86
  87 // This function gives you the point at which you must start braking (at the rate of -acceleration) if
  88 // you started at speed initial_rate and accelerated until this point and want to end at the final_rate after
  89 // a total travel of distance. This can be used to compute the intersection point between acceleration and
  90 // deceleration in the cases where the trapezoid has no plateau (i.e. never reaches maximum speed)
  91 //
  92 /*                          + <- some maximum rate we don't care about
  93                            /|\
  94                           / | \
  95                          /  |  + <- final_rate
  96                         /   |  |
  97        initial_rate -> +----+--+
  98                             ^ ^
  99                             | |
 100         intersection_distance distance */
 101 double Block::intersection_distance(double initialrate, double finalrate, double acceleration, double distance) {
 102    return((2*acceleration*distance-initialrate*initialrate+finalrate*finalrate)/(4*acceleration));
 103 }
 104
 105 // Calculates the maximum allowable speed at this point when you must be able to reach target_velocity using the
 106 // acceleration within the allotted distance.
 107 inline double max_allowable_speed(double acceleration, double target_velocity, double distance) {
 108   return(
 109     sqrt(target_velocity*target_velocity-2L*acceleration*60*60*distance)  //Was acceleration*60*60*distance, in case this breaks, but here we prefer to use seconds instead of minutes
 110   );
 111 }
 112
 113
 114 // Called by Planner::recalculate() when scanning the plan from last to first entry.
 115 void Block::reverse_pass(Block* next, Block* previous){
 116
 117     if (next) {
 118         // If entry speed is already at the maximum entry speed, no need to recheck. Block is cruising.
 119         // If not, block in state of acceleration or deceleration. Reset entry speed to maximum and
 120         // check for maximum allowable speed reductions to ensure maximum possible planned speed.
 121         if (this->entry_speed != this->max_entry_speed) {
 122
 123             // If nominal length true, max junction speed is guaranteed to be reached. Only compute
 124             // for max allowable speed if block is decelerating and nominal length is false.
 125             if ((!this->nominal_length_flag) && (this->max_entry_speed > next->entry_speed)) {
 126                 this->entry_speed = min( this->max_entry_speed, max_allowable_speed(-this->planner->acceleration,next->entry_speed,this->millimeters));
 127             } else {
 128                 this->entry_speed = this->max_entry_speed;
 129             }
 130             this->recalculate_flag = true;
 131
 132         }
 133     } // Skip last block. Already initialized and set for recalculation.
 134
 135 }
 136
 137
 138 // Called by Planner::recalculate() when scanning the plan from first to last entry.
 139 void Block::forward_pass(Block* previous, Block* next){
 140
 141     if(!previous) { return; } // Begin planning after buffer_tail
 142
 143     // If the previous block is an acceleration block, but it is not long enough to complete the
 144     // full speed change within the block, we need to adjust the entry speed accordingly. Entry
 145     // speeds have already been reset, maximized, and reverse planned by reverse planner.
 146     // If nominal length is true, max junction speed is guaranteed to be reached. No need to recheck.
 147     if (!previous->nominal_length_flag) {
 148         if (previous->entry_speed < this->entry_speed) {
 149           double entry_speed = min( this->entry_speed,
 150             max_allowable_speed(-this->planner->acceleration,previous->entry_speed,previous->millimeters) );
 151
 152           // Check for junction speed change
 153           if (this->entry_speed != entry_speed) {
 154             this->entry_speed = entry_speed;
 155             this->recalculate_flag = true;
 156           }
 157         }
 158     }
 159
 160 }
 161
 162
 163 // Gcodes are attached to their respective blocks so that on_gcode_execute can be called with it
 164 void Block::append_gcode(Gcode* gcode){
 165    //this->commands.push_back(gcode->command);
 166    //this->travel_distances.push_back(gcode->millimeters_of_travel);
 167    __disable_irq();
 168    this->gcodes.push_back(*gcode);
 169    __enable_irq();
 170 }
 171
 172 // The attached gcodes are then poped and the on_gcode_execute event is called with them as a parameter
 173 void Block::pop_and_execute_gcode(Kernel* &kernel){
 174     Block* block = const_cast<Block*>(this);
 175     //for(unsigned short index=0; index<block->commands.size(); index++){
 176     //    Gcode gcode = Gcode();
 177     //    gcode.command = block->commands.at(index);
 178     //    gcode.millimeters_of_travel = block->travel_distances.at(index);
 179     //    kernel->call_event(ON_GCODE_EXECUTE, &gcode );
 180     //}
 181     for(unsigned short index=0; index<block->gcodes.size(); index++){
 182         //this->player->kernel->serial->printf("exec: block:%p gcode:%p command:%p \r\n", block, &(block->gcodes[index]), &(block->gcodes[index].command) );
 183         //this->player->kernel->serial->printf("                        str:%s \r\n", block->gcodes[index].command.c_str() );
 184         //wait(0.1);
 185         kernel->call_event(ON_GCODE_EXECUTE, &(block->gcodes[index]));
 186     }
 187 }
 188
 189 // Signal the player that this block is ready to be injected into the system
 190 void Block::ready(){
 191     this->is_ready = true;
 192     this->player->new_block_added();
 193 }
 194
 195 // Mark the block as taken by one more module
 196 void Block::take(){
 197     this->times_taken++;
 198 }
 199
 200 // Mark the block as no longer taken by one module, go to next block if this free's it
 201 void Block::release(){
 202     this->times_taken--;
 203     if( this->times_taken < 1 ){
 204         this->player->kernel->call_event(ON_BLOCK_END, this);
 205         this->pop_and_execute_gcode(this->player->kernel);
 206         Player* player = this->player;
 207
 208         //this->player->kernel->serial->printf("a %d\r\n", this->player->queue.size() );
 209         if( player->queue.size() > 0 ){
 210             player->queue.delete_first();
 211         }
 212
 213         //this->player->kernel->serial->printf("b %d %d\r\n", this->player->queue.size(), player->looking_for_new_block );
 214
 215         if( player->looking_for_new_block == false ){
 216             //player->pop_and_process_new_block(123);
 217             if( player->queue.size() > 0 ){
 218                 Block* candidate =  player->queue.get_ref(0);
 219                 if( candidate->is_ready ){
 220                     //candidate->debug(player->kernel);
 221                     //this->player->kernel->serial->printf("c %d %d\r\n", this->player->queue.size(), player->looking_for_new_block );
 222                     player->current_block = candidate;
 223                     player->kernel->call_event(ON_BLOCK_BEGIN, player->current_block);
 224                     if( player->current_block->times_taken < 1 ){
 225                         player->current_block->release();
 226                     }
 227                 }else{
 228
 229                     player->current_block = NULL;
 230
 231                 }
 232             }else{
 233                 //player->current_block->debug(player->kernel);
 234                 //this->player->kernel->serial->printf("d %d %d\r\n", this->player->queue.size(), player->looking_for_new_block );
 235                 //wait(0.1);
 236                 player->current_block = NULL;
 237             }
 238         }
 239     }
 240 }
 241
 242
 243