Commit | Line | Data |
---|---|---|
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 | 29 | #define acceleration_checksum CHECKSUM("acceleration") |
c5fe1787 | 30 | #define z_acceleration_checksum CHECKSUM("z_acceleration") |
8b69c90d | 31 | #define junction_deviation_checksum CHECKSUM("junction_deviation") |
44de6ef3 | 32 | #define z_junction_deviation_checksum CHECKSUM("z_junction_deviation") |
8b69c90d JM |
33 | #define minimum_planner_speed_checksum CHECKSUM("minimum_planner_speed") |
34 | ||
edac9072 AW |
35 | // The Planner does the acceleration math for the queue of Blocks ( movements ). |
36 | // It makes sure the speed stays within the configured constraints ( acceleration, junction_deviation, etc ) | |
37 | // 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 |
38 | |
39 | Planner::Planner(){ | |
1cf31736 | 40 | clear_vector_float(this->previous_unit_vec); |
558e170c | 41 | config_load(); |
da24d6ae AW |
42 | } |
43 | ||
edac9072 | 44 | // Configure acceleration |
558e170c | 45 | void Planner::config_load(){ |
c5fe1787 JM |
46 | this->acceleration = THEKERNEL->config->value(acceleration_checksum)->by_default(100.0F )->as_number(); // Acceleration is in mm/s^2 |
47 | this->z_acceleration = THEKERNEL->config->value(z_acceleration_checksum)->by_default(0.0F )->as_number(); // disabled by default | |
48 | ||
44de6ef3 JM |
49 | this->junction_deviation = THEKERNEL->config->value(junction_deviation_checksum)->by_default(0.05F)->as_number(); |
50 | this->z_junction_deviation = THEKERNEL->config->value(z_junction_deviation_checksum)->by_default(-1)->as_number(); // disabled by default | |
c5fe1787 | 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 | { | |
44de6ef3 | 58 | float acceleration, junction_deviation; |
c5fe1787 | 59 | |
edac9072 | 60 | // Create ( recycle ) a new block |
2134bcf2 | 61 | Block* block = THEKERNEL->conveyor->queue.head_ref(); |
aab6cbba | 62 | |
c5fe1787 | 63 | |
aab6cbba | 64 | // Direction bits |
78d0e16a MM |
65 | for (int i = 0; i < 3; i++) |
66 | { | |
67 | int steps = THEKERNEL->robot->actuators[i]->steps_to_target(actuator_pos[i]); | |
1cf31736 | 68 | |
558e170c | 69 | block->direction_bits[i] = (steps < 0) ? 1 : 0; |
78d0e16a | 70 | |
338beb48 | 71 | // Update current position |
b2881caa | 72 | THEKERNEL->robot->actuators[i]->last_milestone_steps += steps; |
338beb48 MM |
73 | THEKERNEL->robot->actuators[i]->last_milestone_mm = actuator_pos[i]; |
74 | ||
78d0e16a MM |
75 | block->steps[i] = labs(steps); |
76 | } | |
1cf31736 | 77 | |
44de6ef3 JM |
78 | acceleration= this->acceleration; |
79 | junction_deviation= this->junction_deviation; | |
80 | ||
c5fe1787 | 81 | // use either regular acceleration or a z only move accleration |
44de6ef3 | 82 | if(block->steps[ALPHA_STEPPER] == 0 && block->steps[BETA_STEPPER] == 0) { |
c5fe1787 | 83 | // z only move |
44de6ef3 JM |
84 | if(this->z_acceleration > 0.0F) acceleration= this->z_acceleration; |
85 | if(this->z_junction_deviation >= 0.0F) junction_deviation= this->z_junction_deviation; | |
c5fe1787 JM |
86 | } |
87 | ||
4fdd2470 JM |
88 | block->acceleration= acceleration; // save in block |
89 | ||
4cff3ded AW |
90 | // Max number of steps, for all axes |
91 | block->steps_event_count = max( block->steps[ALPHA_STEPPER], max( block->steps[BETA_STEPPER], block->steps[GAMMA_STEPPER] ) ); | |
92 | ||
4cff3ded | 93 | block->millimeters = distance; |
aab6cbba | 94 | |
9db65137 | 95 | // Calculate speed in mm/sec for each axis. No divide by zero due to previous checks. |
aab6cbba | 96 | // NOTE: Minimum stepper speed is limited by MINIMUM_STEPS_PER_MINUTE in stepper.c |
130275f1 | 97 | if( distance > 0.0F ){ |
da947c62 | 98 | block->nominal_speed = rate_mm_s; // (mm/s) Always > 0 |
9502f9d5 | 99 | block->nominal_rate = ceilf(block->steps_event_count * rate_mm_s / distance); // (step/s) Always > 0 |
436a2cd1 | 100 | }else{ |
130275f1 MM |
101 | block->nominal_speed = 0.0F; |
102 | block->nominal_rate = 0; | |
436a2cd1 | 103 | } |
aab6cbba | 104 | |
4cff3ded AW |
105 | // Compute the acceleration rate for the trapezoid generator. Depending on the slope of the line |
106 | // average travel per step event changes. For a line along one axis the travel per step event | |
107 | // is equal to the travel/step in the particular axis. For a 45 degree line the steppers of both | |
108 | // axes might step for every step event. Travel per step event is then sqrt(travel_x^2+travel_y^2). | |
109 | // To generate trapezoids with contant acceleration between blocks the rate_delta must be computed | |
110 | // specifically for each line to compensate for this phenomenon: | |
aab6cbba | 111 | // Convert universal acceleration for direction-dependent stepper rate change parameter |
a157d099 | 112 | block->rate_delta = (block->steps_event_count * acceleration) / (distance * THEKERNEL->acceleration_ticks_per_second); // (step/min/acceleration_tick) |
1cf31736 | 113 | |
aab6cbba AW |
114 | // Compute maximum allowable entry speed at junction by centripetal acceleration approximation. |
115 | // Let a circle be tangent to both previous and current path line segments, where the junction | |
116 | // deviation is defined as the distance from the junction to the closest edge of the circle, | |
117 | // colinear with the circle center. The circular segment joining the two paths represents the | |
118 | // path of centripetal acceleration. Solve for max velocity based on max acceleration about the | |
119 | // radius of the circle, defined indirectly by junction deviation. This may be also viewed as | |
120 | // path width or max_jerk in the previous grbl version. This approach does not actually deviate | |
121 | // from path, but used as a robust way to compute cornering speeds, as it takes into account the | |
122 | // nonlinearities of both the junction angle and junction velocity. | |
4dfd2dce JM |
123 | |
124 | // NOTE however it does not take into account independent axis, in most cartesian X and Y and Z are totally independent | |
125 | // and this allows one to stop with little to no decleration in many cases. This is particualrly bad on leadscrew based systems that will skip steps. | |
8b69c90d | 126 | float vmax_junction = minimum_planner_speed; // Set default max junction speed |
aab6cbba | 127 | |
38bf9a1c | 128 | if (!THEKERNEL->conveyor->is_queue_empty()) |
e75b3def MM |
129 | { |
130 | float previous_nominal_speed = THEKERNEL->conveyor->queue.item_ref(THEKERNEL->conveyor->queue.prev(THEKERNEL->conveyor->queue.head_i))->nominal_speed; | |
131 | ||
44de6ef3 | 132 | if (previous_nominal_speed > 0.0F && junction_deviation > 0.0F) { |
e75b3def MM |
133 | // Compute cosine of angle between previous and current path. (prev_unit_vec is negative) |
134 | // NOTE: Max junction velocity is computed without sin() or acos() by trig half angle identity. | |
135 | float cos_theta = - this->previous_unit_vec[X_AXIS] * unit_vec[X_AXIS] | |
136 | - this->previous_unit_vec[Y_AXIS] * unit_vec[Y_AXIS] | |
137 | - this->previous_unit_vec[Z_AXIS] * unit_vec[Z_AXIS] ; | |
138 | ||
139 | // Skip and use default max junction speed for 0 degree acute junction. | |
140 | if (cos_theta < 0.95F) { | |
141 | vmax_junction = min(previous_nominal_speed, block->nominal_speed); | |
142 | // Skip and avoid divide by zero for straight junctions at 180 degrees. Limit to min() of nominal speeds. | |
143 | if (cos_theta > -0.95F) { | |
144 | // Compute maximum junction velocity based on maximum acceleration and junction deviation | |
145 | float sin_theta_d2 = sqrtf(0.5F * (1.0F - cos_theta)); // Trig half angle identity. Always positive. | |
44de6ef3 | 146 | vmax_junction = min(vmax_junction, sqrtf(acceleration * junction_deviation * sin_theta_d2 / (1.0F - sin_theta_d2))); |
e75b3def MM |
147 | } |
148 | } | |
aab6cbba | 149 | } |
4cff3ded | 150 | } |
aab6cbba | 151 | block->max_entry_speed = vmax_junction; |
1cf31736 | 152 | |
8b69c90d | 153 | // Initialize block entry speed. Compute based on deceleration to user-defined minimum_planner_speed. |
c9cc5e06 | 154 | float v_allowable = max_allowable_speed(-acceleration, minimum_planner_speed, block->millimeters); |
aab6cbba AW |
155 | block->entry_speed = min(vmax_junction, v_allowable); |
156 | ||
157 | // Initialize planner efficiency flags | |
158 | // Set flag if block will always reach maximum junction speed regardless of entry/exit speeds. | |
159 | // If a block can de/ac-celerate from nominal speed to zero within the length of the block, then | |
160 | // the current block and next block junction speeds are guaranteed to always be at their maximum | |
161 | // junction speeds in deceleration and acceleration, respectively. This is due to how the current | |
162 | // block nominal speed limits both the current and next maximum junction speeds. Hence, in both | |
163 | // the reverse and forward planners, the corresponding block junction speed will always be at the | |
164 | // the maximum junction speed and may always be ignored for any speed reduction checks. | |
165 | if (block->nominal_speed <= v_allowable) { block->nominal_length_flag = true; } | |
166 | else { block->nominal_length_flag = false; } | |
2134bcf2 MM |
167 | |
168 | // Always calculate trapezoid for new block | |
169 | block->recalculate_flag = true; | |
1cf31736 | 170 | |
aab6cbba | 171 | // Update previous path unit_vector and nominal speed |
3a425ecb | 172 | memcpy(this->previous_unit_vec, unit_vec, sizeof(previous_unit_vec)); // previous_unit_vec[] = unit_vec[] |
1cf31736 | 173 | |
df27a6a3 | 174 | // Math-heavy re-computing of the whole queue to take the new |
4cff3ded | 175 | this->recalculate(); |
1cf31736 | 176 | |
df27a6a3 | 177 | // The block can now be used |
3a4fa0c1 | 178 | block->ready(); |
2134bcf2 MM |
179 | |
180 | THEKERNEL->conveyor->queue_head_block(); | |
4cff3ded AW |
181 | } |
182 | ||
4cff3ded | 183 | void Planner::recalculate() { |
a617ac35 | 184 | Conveyor::Queue_t &queue = THEKERNEL->conveyor->queue; |
4dc5513d | 185 | |
a617ac35 | 186 | unsigned int block_index; |
4cff3ded | 187 | |
391bc610 MM |
188 | Block* previous; |
189 | Block* current; | |
391bc610 | 190 | |
a617ac35 MM |
191 | /* |
192 | * a newly added block is decel limited | |
193 | * | |
194 | * we find its max entry speed given its exit speed | |
195 | * | |
d30d9611 MM |
196 | * for each block, walking backwards in the queue: |
197 | * | |
a617ac35 MM |
198 | * if max entry speed == current entry speed |
199 | * then we can set recalculate to false, since clearly adding another block didn't allow us to enter faster | |
d30d9611 MM |
200 | * and thus we don't need to check entry speed for this block any more |
201 | * | |
202 | * once we find an accel limited block, we must find the max exit speed and walk the queue forwards | |
a617ac35 | 203 | * |
d30d9611 | 204 | * for each block, walking forwards in the queue: |
a617ac35 MM |
205 | * |
206 | * given the exit speed of the previous block and our own max entry speed | |
207 | * we can tell if we're accel or decel limited (or coasting) | |
208 | * | |
209 | * if prev_exit > max_entry | |
d30d9611 | 210 | * then we're still decel limited. update previous trapezoid with our max entry for prev exit |
a617ac35 | 211 | * if max_entry >= prev_exit |
d30d9611 | 212 | * then we're accel limited. set recalculate to false, work out max exit speed |
a617ac35 | 213 | * |
d30d9611 | 214 | * finally, work out trapezoid for the final (and newest) block. |
a617ac35 MM |
215 | */ |
216 | ||
217 | /* | |
218 | * Step 1: | |
219 | * For each block, given the exit speed and acceleration, find the maximum entry speed | |
220 | */ | |
221 | ||
222 | float entry_speed = minimum_planner_speed; | |
223 | ||
224 | block_index = queue.head_i; | |
225 | current = queue.item_ref(block_index); | |
226 | ||
227 | if (!queue.is_empty()) | |
391bc610 | 228 | { |
a617ac35 | 229 | while ((block_index != queue.tail_i) && current->recalculate_flag) |
391bc610 | 230 | { |
a617ac35 | 231 | entry_speed = current->reverse_pass(entry_speed); |
391bc610 | 232 | |
a617ac35 MM |
233 | block_index = queue.prev(block_index); |
234 | current = queue.item_ref(block_index); | |
2134bcf2 | 235 | } |
13e4a3f9 | 236 | |
d30d9611 MM |
237 | /* |
238 | * Step 2: | |
239 | * now current points to either tail or first non-recalculate block | |
240 | * and has not had its reverse_pass called | |
241 | * or its calc trap | |
242 | * entry_speed is set to the *exit* speed of current. | |
243 | * each block from current to head has its entry speed set to its max entry speed- limited by decel or nominal_rate | |
244 | */ | |
2134bcf2 | 245 | |
a617ac35 | 246 | float exit_speed = current->max_exit_speed(); |
4cff3ded | 247 | |
a617ac35 MM |
248 | while (block_index != queue.head_i) |
249 | { | |
250 | previous = current; | |
251 | block_index = queue.next(block_index); | |
252 | current = queue.item_ref(block_index); | |
253 | ||
254 | // we pass the exit speed of the previous block | |
255 | // so this block can decide if it's accel or decel limited and update its fields as appropriate | |
256 | exit_speed = current->forward_pass(exit_speed); | |
2134bcf2 | 257 | |
a617ac35 MM |
258 | previous->calculate_trapezoid(previous->entry_speed, current->entry_speed); |
259 | } | |
4cff3ded | 260 | } |
a617ac35 | 261 | |
d30d9611 MM |
262 | /* |
263 | * Step 3: | |
264 | * work out trapezoid for final (and newest) block | |
265 | */ | |
266 | ||
a617ac35 MM |
267 | // now current points to the head item |
268 | // which has not had calculate_trapezoid run yet | |
269 | current->calculate_trapezoid(current->entry_speed, minimum_planner_speed); | |
4cff3ded | 270 | } |
aab6cbba | 271 | |
a617ac35 | 272 | |
aab6cbba AW |
273 | // Calculates the maximum allowable speed at this point when you must be able to reach target_velocity using the |
274 | // acceleration within the allotted distance. | |
1ad23cd3 | 275 | float Planner::max_allowable_speed(float acceleration, float target_velocity, float distance) { |
aab6cbba | 276 | return( |
95b4885b | 277 | 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 |
278 | ); |
279 | } | |
280 | ||
281 |