Commit | Line | Data |
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df27a6a3 | 1 | /* |
5886a464 | 2 | This file is part of Smoothie (http://smoothieware.org/). The motion control part is heavily based on Grbl (https://github.com/simen/grbl) with additions from Sungeun K. Jeon (https://github.com/chamnit/grbl) |
4cff3ded AW |
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. | |
df27a6a3 | 5 | You should have received a copy of the GNU General Public License along with Smoothie. If not, see <http://www.gnu.org/licenses/>. |
4cff3ded AW |
6 | */ |
7 | ||
8 | using namespace std; | |
9 | #include <vector> | |
4dc5513d MM |
10 | |
11 | #include "mri.h" | |
12 | #include "nuts_bolts.h" | |
13 | #include "RingBuffer.h" | |
14 | #include "Gcode.h" | |
15 | #include "Module.h" | |
16 | #include "Kernel.h" | |
4cff3ded AW |
17 | #include "Block.h" |
18 | #include "Planner.h" | |
3fceb8eb | 19 | #include "Conveyor.h" |
5673fe39 | 20 | #include "StepperMotor.h" |
61134a65 JM |
21 | #include "Config.h" |
22 | #include "checksumm.h" | |
23 | #include "Robot.h" | |
24 | #include "Stepper.h" | |
8d54c34c | 25 | #include "ConfigValue.h" |
61134a65 JM |
26 | |
27 | #include <math.h> | |
b66fb830 | 28 | |
8b69c90d JM |
29 | #define acceleration_checksum CHECKSUM("acceleration") |
30 | #define max_jerk_checksum CHECKSUM("max_jerk") | |
31 | #define junction_deviation_checksum CHECKSUM("junction_deviation") | |
32 | #define minimum_planner_speed_checksum CHECKSUM("minimum_planner_speed") | |
33 | ||
edac9072 AW |
34 | // The Planner does the acceleration math for the queue of Blocks ( movements ). |
35 | // It makes sure the speed stays within the configured constraints ( acceleration, junction_deviation, etc ) | |
36 | // It goes over the list in both direction, every time a block is added, re-doing the math to make sure everything is optimal | |
4cff3ded AW |
37 | |
38 | Planner::Planner(){ | |
1cf31736 | 39 | clear_vector_float(this->previous_unit_vec); |
4cff3ded AW |
40 | this->has_deleted_block = false; |
41 | } | |
42 | ||
43 | void Planner::on_module_loaded(){ | |
da24d6ae AW |
44 | this->on_config_reload(this); |
45 | } | |
46 | ||
edac9072 | 47 | // Configure acceleration |
da24d6ae | 48 | void Planner::on_config_reload(void* argument){ |
da947c62 MM |
49 | this->acceleration = THEKERNEL->config->value(acceleration_checksum )->by_default(100.0F )->as_number(); // Acceleration is in mm/s^2, see https://github.com/grbl/grbl/commit/9141ad282540eaa50a41283685f901f29c24ddbd#planner.c |
50 | this->junction_deviation = THEKERNEL->config->value(junction_deviation_checksum )->by_default( 0.05F)->as_number(); | |
8b69c90d | 51 | this->minimum_planner_speed = THEKERNEL->config->value(minimum_planner_speed_checksum )->by_default(0.0f)->as_number(); |
4cff3ded AW |
52 | } |
53 | ||
da24d6ae | 54 | |
4cff3ded | 55 | // Append a block to the queue, compute it's speed factors |
da947c62 MM |
56 | void Planner::append_block( float actuator_pos[], float rate_mm_s, float distance, float unit_vec[] ) |
57 | { | |
edac9072 | 58 | // Create ( recycle ) a new block |
2134bcf2 | 59 | Block* block = THEKERNEL->conveyor->queue.head_ref(); |
aab6cbba AW |
60 | |
61 | // Direction bits | |
df27a6a3 | 62 | block->direction_bits = 0; |
78d0e16a MM |
63 | for (int i = 0; i < 3; i++) |
64 | { | |
65 | int steps = THEKERNEL->robot->actuators[i]->steps_to_target(actuator_pos[i]); | |
1cf31736 | 66 | |
78d0e16a MM |
67 | if (steps < 0) |
68 | block->direction_bits |= (1<<i); | |
69 | ||
338beb48 | 70 | // Update current position |
b2881caa | 71 | THEKERNEL->robot->actuators[i]->last_milestone_steps += steps; |
338beb48 MM |
72 | THEKERNEL->robot->actuators[i]->last_milestone_mm = actuator_pos[i]; |
73 | ||
78d0e16a MM |
74 | block->steps[i] = labs(steps); |
75 | } | |
1cf31736 | 76 | |
4cff3ded AW |
77 | // Max number of steps, for all axes |
78 | block->steps_event_count = max( block->steps[ALPHA_STEPPER], max( block->steps[BETA_STEPPER], block->steps[GAMMA_STEPPER] ) ); | |
79 | ||
4cff3ded | 80 | block->millimeters = distance; |
aab6cbba | 81 | |
9db65137 | 82 | // Calculate speed in mm/sec for each axis. No divide by zero due to previous checks. |
aab6cbba | 83 | // NOTE: Minimum stepper speed is limited by MINIMUM_STEPS_PER_MINUTE in stepper.c |
130275f1 | 84 | if( distance > 0.0F ){ |
da947c62 MM |
85 | block->nominal_speed = rate_mm_s; // (mm/s) Always > 0 |
86 | block->nominal_rate = ceil(block->steps_event_count * rate_mm_s / distance); // (step/s) Always > 0 | |
436a2cd1 | 87 | }else{ |
130275f1 MM |
88 | block->nominal_speed = 0.0F; |
89 | block->nominal_rate = 0; | |
436a2cd1 | 90 | } |
aab6cbba | 91 | |
4cff3ded AW |
92 | // Compute the acceleration rate for the trapezoid generator. Depending on the slope of the line |
93 | // average travel per step event changes. For a line along one axis the travel per step event | |
94 | // is equal to the travel/step in the particular axis. For a 45 degree line the steppers of both | |
95 | // axes might step for every step event. Travel per step event is then sqrt(travel_x^2+travel_y^2). | |
96 | // To generate trapezoids with contant acceleration between blocks the rate_delta must be computed | |
97 | // specifically for each line to compensate for this phenomenon: | |
aab6cbba | 98 | // Convert universal acceleration for direction-dependent stepper rate change parameter |
38bf9a1c | 99 | block->rate_delta = (block->steps_event_count * acceleration) / (distance * THEKERNEL->stepper->get_acceleration_ticks_per_second()); // (step/min/acceleration_tick) |
1cf31736 | 100 | |
aab6cbba AW |
101 | // Compute maximum allowable entry speed at junction by centripetal acceleration approximation. |
102 | // Let a circle be tangent to both previous and current path line segments, where the junction | |
103 | // deviation is defined as the distance from the junction to the closest edge of the circle, | |
104 | // colinear with the circle center. The circular segment joining the two paths represents the | |
105 | // path of centripetal acceleration. Solve for max velocity based on max acceleration about the | |
106 | // radius of the circle, defined indirectly by junction deviation. This may be also viewed as | |
107 | // path width or max_jerk in the previous grbl version. This approach does not actually deviate | |
108 | // from path, but used as a robust way to compute cornering speeds, as it takes into account the | |
109 | // nonlinearities of both the junction angle and junction velocity. | |
8b69c90d | 110 | float vmax_junction = minimum_planner_speed; // Set default max junction speed |
aab6cbba | 111 | |
38bf9a1c | 112 | if (!THEKERNEL->conveyor->is_queue_empty()) |
e75b3def MM |
113 | { |
114 | float previous_nominal_speed = THEKERNEL->conveyor->queue.item_ref(THEKERNEL->conveyor->queue.prev(THEKERNEL->conveyor->queue.head_i))->nominal_speed; | |
115 | ||
116 | if (previous_nominal_speed > 0.0F) { | |
117 | // Compute cosine of angle between previous and current path. (prev_unit_vec is negative) | |
118 | // NOTE: Max junction velocity is computed without sin() or acos() by trig half angle identity. | |
119 | float cos_theta = - this->previous_unit_vec[X_AXIS] * unit_vec[X_AXIS] | |
120 | - this->previous_unit_vec[Y_AXIS] * unit_vec[Y_AXIS] | |
121 | - this->previous_unit_vec[Z_AXIS] * unit_vec[Z_AXIS] ; | |
122 | ||
123 | // Skip and use default max junction speed for 0 degree acute junction. | |
124 | if (cos_theta < 0.95F) { | |
125 | vmax_junction = min(previous_nominal_speed, block->nominal_speed); | |
126 | // Skip and avoid divide by zero for straight junctions at 180 degrees. Limit to min() of nominal speeds. | |
127 | if (cos_theta > -0.95F) { | |
128 | // Compute maximum junction velocity based on maximum acceleration and junction deviation | |
129 | float sin_theta_d2 = sqrtf(0.5F * (1.0F - cos_theta)); // Trig half angle identity. Always positive. | |
130 | vmax_junction = min(vmax_junction, sqrtf(this->acceleration * this->junction_deviation * sin_theta_d2 / (1.0F - sin_theta_d2))); | |
131 | } | |
132 | } | |
aab6cbba | 133 | } |
4cff3ded | 134 | } |
aab6cbba | 135 | block->max_entry_speed = vmax_junction; |
1cf31736 | 136 | |
8b69c90d | 137 | // Initialize block entry speed. Compute based on deceleration to user-defined minimum_planner_speed. |
da947c62 | 138 | float v_allowable = max_allowable_speed(-acceleration, minimum_planner_speed, block->millimeters); //TODO: Get from config |
aab6cbba AW |
139 | block->entry_speed = min(vmax_junction, v_allowable); |
140 | ||
141 | // Initialize planner efficiency flags | |
142 | // Set flag if block will always reach maximum junction speed regardless of entry/exit speeds. | |
143 | // If a block can de/ac-celerate from nominal speed to zero within the length of the block, then | |
144 | // the current block and next block junction speeds are guaranteed to always be at their maximum | |
145 | // junction speeds in deceleration and acceleration, respectively. This is due to how the current | |
146 | // block nominal speed limits both the current and next maximum junction speeds. Hence, in both | |
147 | // the reverse and forward planners, the corresponding block junction speed will always be at the | |
148 | // the maximum junction speed and may always be ignored for any speed reduction checks. | |
149 | if (block->nominal_speed <= v_allowable) { block->nominal_length_flag = true; } | |
150 | else { block->nominal_length_flag = false; } | |
2134bcf2 MM |
151 | |
152 | // Always calculate trapezoid for new block | |
153 | block->recalculate_flag = true; | |
1cf31736 | 154 | |
aab6cbba | 155 | // Update previous path unit_vector and nominal speed |
3a425ecb | 156 | memcpy(this->previous_unit_vec, unit_vec, sizeof(previous_unit_vec)); // previous_unit_vec[] = unit_vec[] |
1cf31736 | 157 | |
df27a6a3 | 158 | // Math-heavy re-computing of the whole queue to take the new |
4cff3ded | 159 | this->recalculate(); |
1cf31736 | 160 | |
df27a6a3 | 161 | // The block can now be used |
3a4fa0c1 | 162 | block->ready(); |
2134bcf2 MM |
163 | |
164 | THEKERNEL->conveyor->queue_head_block(); | |
4cff3ded AW |
165 | } |
166 | ||
4cff3ded | 167 | void Planner::recalculate() { |
a617ac35 | 168 | Conveyor::Queue_t &queue = THEKERNEL->conveyor->queue; |
4dc5513d | 169 | |
a617ac35 | 170 | unsigned int block_index; |
4cff3ded | 171 | |
391bc610 MM |
172 | Block* previous; |
173 | Block* current; | |
391bc610 | 174 | |
a617ac35 MM |
175 | /* |
176 | * a newly added block is decel limited | |
177 | * | |
178 | * we find its max entry speed given its exit speed | |
179 | * | |
d30d9611 MM |
180 | * for each block, walking backwards in the queue: |
181 | * | |
a617ac35 MM |
182 | * if max entry speed == current entry speed |
183 | * then we can set recalculate to false, since clearly adding another block didn't allow us to enter faster | |
d30d9611 MM |
184 | * and thus we don't need to check entry speed for this block any more |
185 | * | |
186 | * once we find an accel limited block, we must find the max exit speed and walk the queue forwards | |
a617ac35 | 187 | * |
d30d9611 | 188 | * for each block, walking forwards in the queue: |
a617ac35 MM |
189 | * |
190 | * given the exit speed of the previous block and our own max entry speed | |
191 | * we can tell if we're accel or decel limited (or coasting) | |
192 | * | |
193 | * if prev_exit > max_entry | |
d30d9611 | 194 | * then we're still decel limited. update previous trapezoid with our max entry for prev exit |
a617ac35 | 195 | * if max_entry >= prev_exit |
d30d9611 | 196 | * then we're accel limited. set recalculate to false, work out max exit speed |
a617ac35 | 197 | * |
d30d9611 | 198 | * finally, work out trapezoid for the final (and newest) block. |
a617ac35 MM |
199 | */ |
200 | ||
201 | /* | |
202 | * Step 1: | |
203 | * For each block, given the exit speed and acceleration, find the maximum entry speed | |
204 | */ | |
205 | ||
206 | float entry_speed = minimum_planner_speed; | |
207 | ||
208 | block_index = queue.head_i; | |
209 | current = queue.item_ref(block_index); | |
210 | ||
211 | if (!queue.is_empty()) | |
391bc610 | 212 | { |
a617ac35 | 213 | while ((block_index != queue.tail_i) && current->recalculate_flag) |
391bc610 | 214 | { |
a617ac35 | 215 | entry_speed = current->reverse_pass(entry_speed); |
391bc610 | 216 | |
a617ac35 MM |
217 | block_index = queue.prev(block_index); |
218 | current = queue.item_ref(block_index); | |
2134bcf2 | 219 | } |
13e4a3f9 | 220 | |
d30d9611 MM |
221 | /* |
222 | * Step 2: | |
223 | * now current points to either tail or first non-recalculate block | |
224 | * and has not had its reverse_pass called | |
225 | * or its calc trap | |
226 | * entry_speed is set to the *exit* speed of current. | |
227 | * each block from current to head has its entry speed set to its max entry speed- limited by decel or nominal_rate | |
228 | */ | |
2134bcf2 | 229 | |
a617ac35 | 230 | float exit_speed = current->max_exit_speed(); |
4cff3ded | 231 | |
a617ac35 MM |
232 | while (block_index != queue.head_i) |
233 | { | |
234 | previous = current; | |
235 | block_index = queue.next(block_index); | |
236 | current = queue.item_ref(block_index); | |
237 | ||
238 | // we pass the exit speed of the previous block | |
239 | // so this block can decide if it's accel or decel limited and update its fields as appropriate | |
240 | exit_speed = current->forward_pass(exit_speed); | |
2134bcf2 | 241 | |
a617ac35 MM |
242 | previous->calculate_trapezoid(previous->entry_speed, current->entry_speed); |
243 | } | |
4cff3ded | 244 | } |
a617ac35 | 245 | |
d30d9611 MM |
246 | /* |
247 | * Step 3: | |
248 | * work out trapezoid for final (and newest) block | |
249 | */ | |
250 | ||
a617ac35 MM |
251 | // now current points to the head item |
252 | // which has not had calculate_trapezoid run yet | |
253 | current->calculate_trapezoid(current->entry_speed, minimum_planner_speed); | |
4cff3ded | 254 | } |
aab6cbba | 255 | |
a617ac35 | 256 | |
aab6cbba AW |
257 | // Calculates the maximum allowable speed at this point when you must be able to reach target_velocity using the |
258 | // acceleration within the allotted distance. | |
1ad23cd3 | 259 | float Planner::max_allowable_speed(float acceleration, float target_velocity, float distance) { |
aab6cbba | 260 | return( |
95b4885b | 261 | sqrtf(target_velocity*target_velocity-2.0F*acceleration*distance) //Was acceleration*60*60*distance, in case this breaks, but here we prefer to use seconds instead of minutes |
aab6cbba AW |
262 | ); |
263 | } | |
264 | ||
265 |