mirror of https://github.com/Desuuuu/klipper.git
140 lines
6.0 KiB
Python
140 lines
6.0 KiB
Python
# Code for handling the kinematics of cartesian robots
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#
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# Copyright (C) 2016 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
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import stepper, homing
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StepList = (0, 1, 2)
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class CartKinematics:
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def __init__(self, printer, config):
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steppers = ['stepper_x', 'stepper_y', 'stepper_z']
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self.steppers = [stepper.PrinterStepper(printer, config.getsection(n))
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for n in steppers]
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self.limits = [(1.0, -1.0)] * 3
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self.stepper_pos = [0, 0, 0]
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def build_config(self):
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for stepper in self.steppers[:2]:
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stepper.set_max_jerk(0.005 * stepper.max_accel) # XXX
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for stepper in self.steppers:
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stepper.build_config()
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def set_position(self, newpos):
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self.stepper_pos = [int(newpos[i]*self.steppers[i].inv_step_dist + 0.5)
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for i in StepList]
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def get_max_speed(self):
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max_xy_speed = min(s.max_velocity for s in self.steppers[:2])
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max_xy_accel = min(s.max_accel for s in self.steppers[:2])
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return max_xy_speed, max_xy_accel
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def get_homed_position(self):
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return [s.position_endstop + s.get_homed_offset()*s.step_dist
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for s in self.steppers]
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def home(self, toolhead, axes):
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# Each axis is homed independently and in order
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homing_state = homing.Homing(toolhead, axes)
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for axis in axes:
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s = self.steppers[axis]
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self.limits[axis] = (s.position_min, s.position_max)
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# Determine moves
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if s.homing_positive_dir:
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pos = s.position_endstop - 1.5*(
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s.position_endstop - s.position_min)
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rpos = s.position_endstop - s.homing_retract_dist
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r2pos = rpos - s.homing_retract_dist
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else:
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pos = s.position_endstop + 1.5*(
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s.position_max - s.position_endstop)
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rpos = s.position_endstop + s.homing_retract_dist
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r2pos = rpos + s.homing_retract_dist
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# Initial homing
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homepos = [None, None, None, None]
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homepos[axis] = s.position_endstop
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coord = [None, None, None, None]
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coord[axis] = pos
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homing_state.plan_home(list(coord), homepos, [s], s.homing_speed)
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# Retract
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coord[axis] = rpos
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homing_state.plan_move(list(coord), s.homing_speed)
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# Home again
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coord[axis] = r2pos
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homing_state.plan_home(list(coord), homepos, [s], s.homing_speed/2.0)
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return homing_state
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def motor_off(self, move_time):
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self.limits = [(1.0, -1.0)] * 3
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for stepper in self.steppers:
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stepper.motor_enable(move_time, 0)
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def query_endstops(self, move_time):
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return homing.QueryEndstops(["x", "y", "z"], self.steppers)
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def check_endstops(self, move):
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end_pos = move.end_pos
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for i in StepList:
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if (move.axes_d[i]
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and (end_pos[i] < self.limits[i][0]
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or end_pos[i] > self.limits[i][1])):
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if self.limits[i][0] > self.limits[i][1]:
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raise homing.EndstopError(end_pos, "Must home axis first")
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raise homing.EndstopError(end_pos)
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def check_move(self, move):
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limits = self.limits
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xpos, ypos = move.end_pos[:2]
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if (xpos < limits[0][0] or xpos > limits[0][1]
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or ypos < limits[1][0] or ypos > limits[1][1]):
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self.check_endstops(move)
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if not move.axes_d[2]:
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# Normal XY move - use defaults
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return
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# Move with Z - update velocity and accel for slower Z axis
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self.check_endstops(move)
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axes_d = move.axes_d
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move_d = move.move_d
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velocity_factor = min([self.steppers[i].max_velocity / abs(axes_d[i])
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for i in StepList if axes_d[i]])
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accel_factor = min([self.steppers[i].max_accel / abs(axes_d[i])
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for i in StepList if axes_d[i]])
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move.limit_speed(velocity_factor * move_d, accel_factor * move_d)
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def move(self, move_time, move):
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inv_accel = 1. / move.accel
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inv_cruise_v = 1. / move.cruise_v
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for i in StepList:
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new_step_pos = int(
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move.end_pos[i]*self.steppers[i].inv_step_dist + 0.5)
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steps = new_step_pos - self.stepper_pos[i]
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if not steps:
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continue
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self.stepper_pos[i] = new_step_pos
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sdir = 0
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if steps < 0:
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sdir = 1
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steps = -steps
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mcu_time, so = self.steppers[i].prep_move(move_time, sdir)
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move_step_d = move.move_d / steps
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step_offset = 0.5
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# Acceleration steps
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#t = sqrt(2*pos/accel + (start_v/accel)**2) - start_v/accel
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accel_time_offset = move.start_v * inv_accel
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accel_sqrt_offset = accel_time_offset**2
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accel_multiplier = 2.0 * move_step_d * inv_accel
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accel_steps = move.accel_r * steps
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step_offset = so.step_sqrt(
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mcu_time - accel_time_offset, accel_steps, step_offset
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, accel_sqrt_offset, accel_multiplier)
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mcu_time += move.accel_t
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# Cruising steps
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#t = pos/cruise_v
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cruise_multiplier = move_step_d * inv_cruise_v
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cruise_steps = move.cruise_r * steps
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step_offset = so.step_factor(
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mcu_time, cruise_steps, step_offset, cruise_multiplier)
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mcu_time += move.cruise_t
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# Deceleration steps
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#t = cruise_v/accel - sqrt((cruise_v/accel)**2 - 2*pos/accel)
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decel_time_offset = move.cruise_v * inv_accel
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decel_sqrt_offset = decel_time_offset**2
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decel_steps = move.decel_r * steps
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so.step_sqrt(
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mcu_time + decel_time_offset, decel_steps, step_offset
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, decel_sqrt_offset, -accel_multiplier)
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