123 lines
5.3 KiB
Python
123 lines
5.3 KiB
Python
# Code for handling the kinematics of polar robots
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#
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# Copyright (C) 2018-2021 Kevin O'Connor <kevin@koconnor.net>
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#
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# This file may be distributed under the terms of the GNU GPLv3 license.
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import logging, math
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import stepper
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class PolarKinematics:
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def __init__(self, toolhead, config):
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# Setup axis steppers
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stepper_bed = stepper.PrinterStepper(config.getsection('stepper_bed'),
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units_in_radians=True)
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rail_arm = stepper.PrinterRail(config.getsection('stepper_arm'))
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rail_z = stepper.LookupMultiRail(config.getsection('stepper_z'))
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stepper_bed.setup_itersolve('polar_stepper_alloc', 'a')
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rail_arm.setup_itersolve('polar_stepper_alloc', 'r')
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rail_z.setup_itersolve('cartesian_stepper_alloc', 'z')
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self.rails = [rail_arm, rail_z]
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self.steppers = [stepper_bed] + [ s for r in self.rails
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for s in r.get_steppers() ]
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for s in self.get_steppers():
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s.set_trapq(toolhead.get_trapq())
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toolhead.register_step_generator(s.generate_steps)
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config.get_printer().register_event_handler("stepper_enable:motor_off",
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self._motor_off)
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# Setup boundary checks
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max_velocity, max_accel = toolhead.get_max_velocity()
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self.max_z_velocity = config.getfloat(
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'max_z_velocity', max_velocity, above=0., maxval=max_velocity)
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self.max_z_accel = config.getfloat(
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'max_z_accel', max_accel, above=0., maxval=max_accel)
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self.limit_z = (1.0, -1.0)
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self.limit_xy2 = -1.
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max_xy = self.rails[0].get_range()[1]
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min_z, max_z = self.rails[1].get_range()
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self.axes_min = toolhead.Coord(-max_xy, -max_xy, min_z, 0.)
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self.axes_max = toolhead.Coord(max_xy, max_xy, max_z, 0.)
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# Setup stepper max halt velocity
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max_halt_velocity = toolhead.get_max_axis_halt()
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stepper_bed.set_max_jerk(max_halt_velocity, max_accel)
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rail_arm.set_max_jerk(max_halt_velocity, max_accel)
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rail_z.set_max_jerk(max_halt_velocity, max_accel)
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def get_steppers(self):
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return list(self.steppers)
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def calc_tag_position(self):
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bed_angle = self.steppers[0].get_tag_position()
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arm_pos = self.rails[0].get_tag_position()
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z_pos = self.rails[1].get_tag_position()
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return [math.cos(bed_angle) * arm_pos, math.sin(bed_angle) * arm_pos,
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z_pos]
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def set_position(self, newpos, homing_axes):
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for s in self.steppers:
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s.set_position(newpos)
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if 2 in homing_axes:
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self.limit_z = self.rails[1].get_range()
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if 0 in homing_axes and 1 in homing_axes:
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self.limit_xy2 = self.rails[0].get_range()[1]**2
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def note_z_not_homed(self):
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# Helper for Safe Z Home
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self.limit_z = (1.0, -1.0)
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def _home_axis(self, homing_state, axis, rail):
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# Determine movement
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position_min, position_max = rail.get_range()
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hi = rail.get_homing_info()
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homepos = [None, None, None, None]
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homepos[axis] = hi.position_endstop
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if axis == 0:
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homepos[1] = 0.
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forcepos = list(homepos)
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if hi.positive_dir:
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forcepos[axis] -= hi.position_endstop - position_min
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else:
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forcepos[axis] += position_max - hi.position_endstop
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# Perform homing
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homing_state.home_rails([rail], forcepos, homepos)
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def home(self, homing_state):
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# Always home XY together
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homing_axes = homing_state.get_axes()
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home_xy = 0 in homing_axes or 1 in homing_axes
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home_z = 2 in homing_axes
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updated_axes = []
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if home_xy:
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updated_axes = [0, 1]
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if home_z:
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updated_axes.append(2)
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homing_state.set_axes(updated_axes)
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# Do actual homing
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if home_xy:
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self._home_axis(homing_state, 0, self.rails[0])
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if home_z:
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self._home_axis(homing_state, 2, self.rails[1])
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def _motor_off(self, print_time):
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self.limit_z = (1.0, -1.0)
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self.limit_xy2 = -1.
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def check_move(self, move):
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end_pos = move.end_pos
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xy2 = end_pos[0]**2 + end_pos[1]**2
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if xy2 > self.limit_xy2:
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if self.limit_xy2 < 0.:
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raise move.move_error("Must home axis first")
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raise move.move_error()
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if move.axes_d[2]:
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if end_pos[2] < self.limit_z[0] or end_pos[2] > self.limit_z[1]:
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if self.limit_z[0] > self.limit_z[1]:
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raise move.move_error("Must home axis first")
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raise move.move_error()
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# Move with Z - update velocity and accel for slower Z axis
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z_ratio = move.move_d / abs(move.axes_d[2])
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move.limit_speed(self.max_z_velocity * z_ratio,
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self.max_z_accel * z_ratio)
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def get_status(self, eventtime):
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xy_home = "xy" if self.limit_xy2 >= 0. else ""
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z_home = "z" if self.limit_z[0] <= self.limit_z[1] else ""
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return {
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'homed_axes': xy_home + z_home,
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'axis_minimum': self.axes_min,
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'axis_maximum': self.axes_max,
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}
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def load_kinematics(toolhead, config):
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return PolarKinematics(toolhead, config)
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