#!/usr/bin/env python3 # Copyright (c) 2020 Ultimaker B.V. # Cura is released under the terms of the LGPLv3 or higher. import copy import math import os import sys from typing import Dict, List, Optional, Tuple # ==================================== # Constants and Default Values # ==================================== DEFAULT_BUFFER_FILLING_RATE_IN_C_PER_S = 50.0 # The buffer filling rate in #commands/s DEFAULT_BUFFER_SIZE = 15 # The buffer size in #commands MINIMUM_PLANNER_SPEED = 0.05 #Setting values for Ultimaker S5. MACHINE_MAX_FEEDRATE_X = 300 MACHINE_MAX_FEEDRATE_Y = 300 MACHINE_MAX_FEEDRATE_Z = 40 MACHINE_MAX_FEEDRATE_E = 45 MACHINE_MAX_ACCELERATION_X = 9000 MACHINE_MAX_ACCELERATION_Y = 9000 MACHINE_MAX_ACCELERATION_Z = 100 MACHINE_MAX_ACCELERATION_E = 10000 MACHINE_MAX_JERK_XY = 20 MACHINE_MAX_JERK_Z = 0.4 MACHINE_MAX_JERK_E = 5 MACHINE_MINIMUM_FEEDRATE = 0.001 MACHINE_ACCELERATION = 3000 def get_code_and_num(gcode_line: str) -> Tuple[str, str]: """Gets the code and number from the given g-code line.""" gcode_line = gcode_line.strip() cmd_code = gcode_line[0].upper() cmd_num = str(gcode_line[1:]) return cmd_code, cmd_num def get_value_dict(parts: List[str]) -> Dict[str, str]: """Fetches arguments such as X1 Y2 Z3 from the given part list and returns a dict""" value_dict = {} for p in parts: p = p.strip() if not p: continue code, num = get_code_and_num(p) value_dict[code] = num return value_dict # ============================ # Math Functions - Begin # ============================ def calc_distance(pos1, pos2): delta = {k: pos1[k] - pos2[k] for k in pos1} distance = 0 for value in delta.values(): distance += value ** 2 distance = math.sqrt(distance) return distance def calc_acceleration_distance(init_speed: float, target_speed: float, acceleration: float) -> float: """Given the initial speed, the target speed, and the acceleration calculate the distance that's needed for the acceleration to finish. """ if acceleration == 0: return 0.0 return (target_speed ** 2 - init_speed ** 2) / (2 * acceleration) def calc_acceleration_time_from_distance(initial_feedrate: float, distance: float, acceleration: float) -> float: """Gives the time it needs to accelerate from an initial speed to reach a final distance.""" discriminant = initial_feedrate ** 2 - 2 * acceleration * -distance #If the discriminant is negative, we're moving in the wrong direction. #Making the discriminant 0 then gives the extremum of the parabola instead of the intersection. discriminant = max(0, discriminant) return (-initial_feedrate + math.sqrt(discriminant)) / acceleration def calc_intersection_distance(initial_feedrate: float, final_feedrate: float, acceleration: float, distance: float) -> float: """Calculates the point at which you must start braking. This gives the distance from the start of a line at which you must start decelerating (at a rate of `-acceleration`) if you started at speed `initial_feedrate` and accelerated until this point and want to end at the `final_feedrate` after a total travel of `distance`. This can be used to compute the intersection point between acceleration and deceleration in the cases where the trapezoid has no plateau (i.e. never reaches maximum speed). """ if acceleration == 0: return 0 return (2 * acceleration * distance - initial_feedrate * initial_feedrate + final_feedrate * final_feedrate) / (4 * acceleration) def calc_max_allowable_speed(acceleration: float, target_velocity: float, distance: float) -> float: """Calculates the maximum speed that is allowed at this point when you must be able to reach target_velocity using the acceleration within the allotted distance. """ return math.sqrt(target_velocity * target_velocity - 2 * acceleration * distance) class Command: def __init__(self, cmd_str: str) -> None: self._cmd_str = cmd_str # type: str self.estimated_exec_time = 0.0 # type: float self._cmd_process_function_map = { "G": self._handle_g, "M": self._handle_m, "T": self._handle_t, } self._is_comment = False # type: bool self._is_empty = False # type: bool #Fields taken from CuraEngine's implementation. self._recalculate = False self._accelerate_until = 0 self._decelerate_after = 0 self._initial_feedrate = 0 self._final_feedrate = 0 self._entry_speed = 0 self._max_entry_speed =0 self._nominal_length = False self._nominal_feedrate = 0 self._max_travel = 0 self._distance = 0 self._acceleration = 0 self._delta = [0, 0, 0] self._abs_delta = [0, 0, 0] def calculate_trapezoid(self, entry_factor, exit_factor): """Calculate the velocity-time trapezoid function for this move. Each move has a three-part function mapping time to velocity. """ initial_feedrate = self._nominal_feedrate * entry_factor final_feedrate = self._nominal_feedrate * exit_factor #How far are we accelerating and how far are we decelerating? accelerate_distance = calc_acceleration_distance(initial_feedrate, self._nominal_feedrate, self._acceleration) decelerate_distance = calc_acceleration_distance(self._nominal_feedrate, final_feedrate, -self._acceleration) plateau_distance = self._distance - accelerate_distance - decelerate_distance #And how far in between at max speed? #Is the plateau negative size? That means no cruising, and we'll have to #use intersection_distance to calculate when to abort acceleration and #start braking in order to reach the final_rate exactly at the end of #this command. if plateau_distance < 0: accelerate_distance = calc_intersection_distance(initial_feedrate, final_feedrate, self._acceleration, self._distance) accelerate_distance = max(accelerate_distance, 0) #Due to rounding errors. accelerate_distance = min(accelerate_distance, self._distance) plateau_distance = 0 self._accelerate_until = accelerate_distance self._decelerate_after = accelerate_distance + plateau_distance self._initial_feedrate = initial_feedrate self._final_feedrate = final_feedrate @property def is_command(self) -> bool: return not self._is_comment and not self._is_empty def __str__(self) -> str: if self._is_comment or self._is_empty: return self._cmd_str info = "t=%s" % (self.estimated_exec_time) return self._cmd_str.strip() + " ; --- " + info + os.linesep def parse(self) -> None: """Estimates the execution time of this command and calculates the state after this command is executed.""" line = self._cmd_str.strip() if not line: self._is_empty = True return if line.startswith(";"): self._is_comment = True return # Remove comment line = line.split(";", 1)[0].strip() parts = line.split(" ") cmd_code, cmd_num = get_code_and_num(parts[0]) cmd_num = int(cmd_num) func = self._cmd_process_function_map.get(cmd_code) if func is None: print("!!! no handle function for command type [%s]" % cmd_code) return func(cmd_num, parts) def _handle_g(self, cmd_num: int, parts: List[str]) -> None: self.estimated_exec_time = 0.0 # G10: Retract. Make this behave as if it's a retraction of 25mm. if cmd_num == 10: #TODO: If already retracted, this shouldn't add anything to the time. cmd_num = 1 parts = ["G1", "E" + str(buf.current_position[3] - 25)] # G11: Unretract. Make this behave as if it's an unretraction of 25mm. elif cmd_num == 11: #TODO: If already unretracted, this shouldn't add anything to the time. cmd_num = 1 parts = ["G1", "E" + str(buf.current_position[3] + 25)] # G0 and G1: Move if cmd_num in (0, 1): # Move if len(parts) > 0: value_dict = get_value_dict(parts[1:]) new_position = copy.deepcopy(buf.current_position) new_position[0] = float(value_dict.get("X", new_position[0])) new_position[1] = float(value_dict.get("Y", new_position[1])) new_position[2] = float(value_dict.get("Z", new_position[2])) new_position[3] = float(value_dict.get("E", new_position[3])) buf.current_feedrate = float(value_dict.get("F", buf.current_feedrate * 60.0)) / 60.0 if buf.current_feedrate < MACHINE_MINIMUM_FEEDRATE: buf.current_feedrate = MACHINE_MINIMUM_FEEDRATE self._delta = [ new_position[0] - buf.current_position[0], new_position[1] - buf.current_position[1], new_position[2] - buf.current_position[2], new_position[3] - buf.current_position[3] ] self._abs_delta = [abs(x) for x in self._delta] self._max_travel = max(self._abs_delta) if self._max_travel > 0: self._nominal_feedrate = buf.current_feedrate self._distance = math.sqrt(self._abs_delta[0] ** 2 + self._abs_delta[1] ** 2 + self._abs_delta[2] ** 2) if self._distance == 0: self._distance = self._abs_delta[3] current_feedrate = [d * self._nominal_feedrate / self._distance for d in self._delta] current_abs_feedrate = [abs(f) for f in current_feedrate] feedrate_factor = min(1.0, MACHINE_MAX_FEEDRATE_X) feedrate_factor = min(feedrate_factor, MACHINE_MAX_FEEDRATE_Y) feedrate_factor = min(feedrate_factor, buf.max_z_feedrate) feedrate_factor = min(feedrate_factor, MACHINE_MAX_FEEDRATE_E) #TODO: XY_FREQUENCY_LIMIT current_feedrate = [f * feedrate_factor for f in current_feedrate] current_abs_feedrate = [f * feedrate_factor for f in current_abs_feedrate] self._nominal_feedrate *= feedrate_factor self._acceleration = MACHINE_ACCELERATION max_accelerations = [MACHINE_MAX_ACCELERATION_X, MACHINE_MAX_ACCELERATION_Y, MACHINE_MAX_ACCELERATION_Z, MACHINE_MAX_ACCELERATION_E] for n in range(len(max_accelerations)): if self._acceleration * self._abs_delta[n] / self._distance > max_accelerations[n]: self._acceleration = max_accelerations[n] vmax_junction = MACHINE_MAX_JERK_XY / 2 vmax_junction_factor = 1.0 if current_abs_feedrate[2] > buf.max_z_jerk / 2: vmax_junction = min(vmax_junction, buf.max_z_jerk) if current_abs_feedrate[3] > buf.max_e_jerk / 2: vmax_junction = min(vmax_junction, buf.max_e_jerk) vmax_junction = min(vmax_junction, self._nominal_feedrate) safe_speed = vmax_junction if buf.previous_nominal_feedrate > 0.0001: xy_jerk = math.sqrt((current_feedrate[0] - buf.previous_feedrate[0]) ** 2 + (current_feedrate[1] - buf.previous_feedrate[1]) ** 2) vmax_junction = self._nominal_feedrate if xy_jerk > MACHINE_MAX_JERK_XY: vmax_junction_factor = MACHINE_MAX_JERK_XY / xy_jerk if abs(current_feedrate[2] - buf.previous_feedrate[2]) > MACHINE_MAX_JERK_Z: vmax_junction_factor = min(vmax_junction_factor, (MACHINE_MAX_JERK_Z / abs(current_feedrate[2] - buf.previous_feedrate[2]))) if abs(current_feedrate[3] - buf.previous_feedrate[3]) > MACHINE_MAX_JERK_E: vmax_junction_factor = min(vmax_junction_factor, (MACHINE_MAX_JERK_E / abs(current_feedrate[3] - buf.previous_feedrate[3]))) vmax_junction = min(buf.previous_nominal_feedrate, vmax_junction * vmax_junction_factor) #Limit speed to max previous speed. self._max_entry_speed = vmax_junction v_allowable = calc_max_allowable_speed(-self._acceleration, MINIMUM_PLANNER_SPEED, self._distance) self._entry_speed = min(vmax_junction, v_allowable) self._nominal_length = self._nominal_feedrate <= v_allowable self._recalculate = True buf.previous_feedrate = current_feedrate buf.previous_nominal_feedrate = self._nominal_feedrate buf.current_position = new_position self.calculate_trapezoid(self._entry_speed / self._nominal_feedrate, safe_speed / self._nominal_feedrate) self.estimated_exec_time = -1 #Signal that we need to include this in our second pass. # G4: Dwell, pause the machine for a period of time. elif cmd_num == 4: # Pnnn is time to wait in milliseconds (P0 wait until all previous moves are finished) cmd, num = get_code_and_num(parts[1]) num = float(num) if cmd == "P": if num > 0: self.estimated_exec_time = num def _handle_m(self, cmd_num: int, parts: List[str]) -> None: self.estimated_exec_time = 0.0 # M203: Set maximum feedrate. Only Z is supported. Assume 0 execution time. if cmd_num == 203: value_dict = get_value_dict(parts[1:]) buf.max_z_feedrate = value_dict.get("Z", buf.max_z_feedrate) # M204: Set default acceleration. Assume 0 execution time. if cmd_num == 204: value_dict = get_value_dict(parts[1:]) buf.acceleration = value_dict.get("S", buf.acceleration) # M205: Advanced settings, we only set jerks for Griffin. Assume 0 execution time. if cmd_num == 205: value_dict = get_value_dict(parts[1:]) buf.max_xy_jerk = value_dict.get("XY", buf.max_xy_jerk) buf.max_z_jerk = value_dict.get("Z", buf.max_z_jerk) buf.max_e_jerk = value_dict.get("E", buf.max_e_jerk) def _handle_t(self, cmd_num: int, parts: List[str]) -> None: # Tn: Switching extruder. Assume 0 seconds. Actually more like 2. self.estimated_exec_time = 0.0 class CommandBuffer: def __init__(self, all_lines: List[str], buffer_filling_rate: float = DEFAULT_BUFFER_FILLING_RATE_IN_C_PER_S, buffer_size: int = DEFAULT_BUFFER_SIZE ) -> None: self._all_lines = all_lines self._all_commands = list() self._buffer_filling_rate = buffer_filling_rate # type: float self._buffer_size = buffer_size # type: int self.acceleration = 3000 self.current_position = [0, 0, 0, 0] self.current_feedrate = 0 self.max_xy_jerk = MACHINE_MAX_JERK_XY self.max_z_jerk = MACHINE_MAX_JERK_Z self.max_e_jerk = MACHINE_MAX_JERK_E self.max_z_feedrate = MACHINE_MAX_FEEDRATE_Z # If the buffer can depletes less than this amount time, it can be filled up in time. lower_bound_buffer_depletion_time = self._buffer_size / self._buffer_filling_rate # type: float self._detection_time_frame = lower_bound_buffer_depletion_time self._code_count_limit = self._buffer_size self.total_time = 0.0 self.previous_feedrate = [0, 0, 0, 0] self.previous_nominal_feedrate = 0 print("Command speed: %s" % buffer_filling_rate) print("Code Limit: %s" % self._code_count_limit) self._bad_frame_ranges = [] def process(self) -> None: buf.total_time = 0.0 cmd0_idx = 0 total_frame_time = 0.0 cmd_count = 0 for idx, line in enumerate(self._all_lines): cmd = Command(line) cmd.parse() if not cmd.is_command: continue self._all_commands.append(cmd) #Second pass: Reverse kernel. kernel_commands = [None, None, None] for cmd in reversed(self._all_commands): if cmd.estimated_exec_time >= 0: continue #Not a movement command. kernel_commands[2] = kernel_commands[1] kernel_commands[1] = kernel_commands[0] kernel_commands[0] = cmd self.reverse_pass_kernel(kernel_commands[0], kernel_commands[1], kernel_commands[2]) #Third pass: Forward kernel. kernel_commands = [None, None, None] for cmd in self._all_commands: if cmd.estimated_exec_time >= 0: continue #Not a movement command. kernel_commands[0] = kernel_commands[1] kernel_commands[1] = kernel_commands[2] kernel_commands[2] = cmd self.forward_pass_kernel(kernel_commands[0], kernel_commands[1], kernel_commands[2]) self.forward_pass_kernel(kernel_commands[1], kernel_commands[2], None) #Fourth pass: Recalculate the commands that have _recalculate set. previous = None current = None for current in self._all_commands: if current.estimated_exec_time >= 0: current = None continue #Not a movement command. if previous: #Recalculate if current command entry or exit junction speed has changed. if previous._recalculate or current._recalculate: #Note: Entry and exit factors always >0 by all previous logic operators. previous.calculate_trapezoid(previous._entry_speed / previous._nominal_feedrate, current._entry_speed / previous._nominal_feedrate) previous._recalculate = False previous = current if current is not None and current.estimated_exec_time >= 0: current.calculate_trapezoid(current._entry_speed / current._nominal_feedrate, MINIMUM_PLANNER_SPEED / current._nominal_feedrate) current._recalculate = False #Fifth pass: Compute time for movement commands. for cmd in self._all_commands: if cmd.estimated_exec_time >= 0: continue #Not a movement command. plateau_distance = cmd._decelerate_after - cmd._accelerate_until cmd.estimated_exec_time = calc_acceleration_time_from_distance(cmd._initial_feedrate, cmd._accelerate_until, cmd._acceleration) cmd.estimated_exec_time += plateau_distance / cmd._nominal_feedrate cmd.estimated_exec_time += calc_acceleration_time_from_distance(cmd._final_feedrate, (cmd._distance - cmd._decelerate_after), cmd._acceleration) for idx, cmd in enumerate(self._all_commands): cmd_count += 1 if idx > cmd0_idx or idx == 0: buf.total_time += cmd.estimated_exec_time total_frame_time += cmd.estimated_exec_time if total_frame_time > 1: # Find the next starting command which makes the total execution time of the frame to be less than # 1 second. cmd0_idx += 1 total_frame_time -= self._all_commands[cmd0_idx].estimated_exec_time cmd_count -= 1 while total_frame_time > 1: cmd0_idx += 1 total_frame_time -= self._all_commands[cmd0_idx].estimated_exec_time cmd_count -= 1 # If within the current time frame the code count exceeds the limit, record that. if total_frame_time <= self._detection_time_frame and cmd_count > self._code_count_limit: need_to_append = True if self._bad_frame_ranges: last_item = self._bad_frame_ranges[-1] if last_item["start_line"] == cmd0_idx: last_item["end_line"] = idx last_item["cmd_count"] = cmd_count last_item["time"] = total_frame_time need_to_append = False if need_to_append: self._bad_frame_ranges.append({"start_line": cmd0_idx, "end_line": idx, "cmd_count": cmd_count, "time": total_frame_time}) def reverse_pass_kernel(self, previous: Optional[Command], current: Optional[Command], next: Optional[Command]) -> None: if not current or not next: return #If entry speed is already at the maximum entry speed, no need to #recheck. The command is cruising. If not, the command is in state of #acceleration or deceleration. Reset entry speed to maximum and check #for maximum allowable speed reductions to ensure maximum possible #planned speed. if current._entry_speed != current._max_entry_speed: #If nominal length is true, max junction speed is guaranteed to be #reached. Only compute for max allowable speed if block is #decelerating and nominal length is false. if not current._nominal_length and current._max_entry_speed > next._max_entry_speed: current._entry_speed = min(current._max_entry_speed, calc_max_allowable_speed(-current._acceleration, next._entry_speed, current._distance)) else: current._entry_speed = current._max_entry_speed current._recalculate = True def forward_pass_kernel(self, previous: Optional[Command], current: Optional[Command], next: Optional[Command]) -> None: if not previous: return #If the previous command is an acceleration command, but it is not long #enough to complete the full speed change within the command, we need to #adjust the entry speed accordingly. Entry speeds have already been #reset, maximised and reverse planned by the reverse planner. If nominal #length is set, max junction speed is guaranteed to be reached. No need #to recheck. if not previous._nominal_length: if previous._entry_speed < current._entry_speed: entry_speed = min(current._entry_speed, calc_max_allowable_speed(-previous._acceleration, previous._entry_speed, previous._distance)) if current._entry_speed != entry_speed: current._entry_speed = entry_speed current._recalculate = True def to_file(self, file_name: str) -> None: all_lines = [str(c) for c in self._all_commands] with open(file_name, "w", encoding = "utf-8") as f: f.writelines(all_lines) f.write(";---TOTAL ESTIMATED TIME:" + str(self.total_time)) def report(self) -> None: for item in self._bad_frame_ranges: print("Potential buffer underrun from line {start_line} to {end_line}, code count = {code_count}, in {time}s ({speed} cmd/s)".format( start_line = item["start_line"], end_line = item["end_line"], code_count = item["cmd_count"], time = round(item["time"], 4), speed = round(item["cmd_count"] / item["time"], 2))) print("Total predicted number of buffer underruns:", len(self._bad_frame_ranges)) if __name__ == "__main__": if len(sys.argv) < 2 or 3 < len(sys.argv): print("Usage: [output g-code]") sys.exit(1) in_filename = sys.argv[1] out_filename = None if len(sys.argv) == 3: out_filename = sys.argv[2] with open(in_filename, "r", encoding = "utf-8") as f: all_lines = f.readlines() buf = CommandBuffer(all_lines) buf.process() # Output annotated gcode is optional if out_filename is not None: buf.to_file(out_filename) buf.report()