kinematics: Add hybrid-corexy and hybrid-corexz (#4229)

Signed-off-by: Fabrice GALLET <tircown@gmail.com>

klippy/kinematics/hybrid_corexz.py

@@ -0,0 +1,100 @@
+# Code for handling the kinematics of hybrid-corexz robots
+#
+# Copyright (C) 2021  Fabrice Gallet <tircown@gmail.com>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+import logging
+import stepper
+
+# The hybrid-corexz kinematic is also known as Markforged kinematics
+class HybridCoreXZKinematics:
+    def __init__(self, toolhead, config):
+        self.printer = config.get_printer()
+        printer_config = config.getsection('printer')
+        # itersolve parameters
+        self.rails = [ stepper.PrinterRail(config.getsection('stepper_x')),
+                       stepper.LookupMultiRail(config.getsection('stepper_y')),
+                       stepper.LookupMultiRail(config.getsection('stepper_z'))]
+        self.rails[2].get_endstops()[0][0].add_stepper(
+            self.rails[0].get_steppers()[0])
+        self.rails[0].setup_itersolve('corexz_stepper_alloc', '-')
+        self.rails[1].setup_itersolve('cartesian_stepper_alloc', 'y')
+        self.rails[2].setup_itersolve('cartesian_stepper_alloc', 'z')
+        ranges = [r.get_range() for r in self.rails]
+        self.axes_min = toolhead.Coord(*[r[0] for r in ranges], e=0.)
+        self.axes_max = toolhead.Coord(*[r[1] for r in ranges], e=0.)
+        for s in self.get_steppers():
+            s.set_trapq(toolhead.get_trapq())
+            toolhead.register_step_generator(s.generate_steps)
+        self.printer.register_event_handler("stepper_enable:motor_off",
+                                                    self._motor_off)
+        # Setup boundary checks
+        max_velocity, max_accel = toolhead.get_max_velocity()
+        self.max_z_velocity = config.getfloat(
+            'max_z_velocity', max_velocity, above=0., maxval=max_velocity)
+        self.max_z_accel = config.getfloat(
+            'max_z_accel', max_accel, above=0., maxval=max_accel)
+        self.limits = [(1.0, -1.0)] * 3
+    def get_steppers(self):
+        return [s for rail in self.rails for s in rail.get_steppers()]
+    def calc_tag_position(self):
+        pos = [rail.get_tag_position() for rail in self.rails]
+        return [pos[0] + pos[2], pos[1], pos[2]]
+    def set_position(self, newpos, homing_axes):
+        for i, rail in enumerate(self.rails):
+            rail.set_position(newpos)
+            if i in homing_axes:
+                self.limits[i] = rail.get_range()
+    def note_z_not_homed(self):
+        # Helper for Safe Z Home
+        self.limits[2] = (1.0, -1.0)
+    def _home_axis(self, homing_state, axis, rail):
+        position_min, position_max = rail.get_range()
+        hi = rail.get_homing_info()
+        homepos = [None, None, None, None]
+        homepos[axis] = hi.position_endstop
+        forcepos = list(homepos)
+        if hi.positive_dir:
+            forcepos[axis] -= 1.5 * (hi.position_endstop - position_min)
+        else:
+            forcepos[axis] += 1.5 * (position_max - hi.position_endstop)
+        # Perform homing
+        homing_state.home_rails([rail], forcepos, homepos)
+    def home(self, homing_state):
+        for axis in homing_state.get_axes():
+            self._home_axis(homing_state, axis, self.rails[axis])
+    def _motor_off(self, print_time):
+        self.limits = [(1.0, -1.0)] * 3
+    def _check_endstops(self, move):
+        end_pos = move.end_pos
+        for i in (0, 1, 2):
+            if (move.axes_d[i]
+                and (end_pos[i] < self.limits[i][0]
+                     or end_pos[i] > self.limits[i][1])):
+                if self.limits[i][0] > self.limits[i][1]:
+                    raise move.move_error("Must home axis first")
+                raise move.move_error()
+    def check_move(self, move):
+        limits = self.limits
+        xpos, ypos = move.end_pos[:2]
+        if (xpos < limits[0][0] or xpos > limits[0][1]
+            or ypos < limits[1][0] or ypos > limits[1][1]):
+            self._check_endstops(move)
+        if not move.axes_d[2]:
+            # Normal XY move - use defaults
+            return
+        # Move with Z - update velocity and accel for slower Z axis
+        self._check_endstops(move)
+        z_ratio = move.move_d / abs(move.axes_d[2])
+        move.limit_speed(
+            self.max_z_velocity * z_ratio, self.max_z_accel * z_ratio)
+    def get_status(self, eventtime):
+        axes = [a for a, (l, h) in zip("xyz", self.limits) if l <= h]
+        return {
+            'homed_axes': "".join(axes),
+            'axis_minimum': self.axes_min,
+            'axis_maximum': self.axes_max,
+        }
+
+def load_kinematics(toolhead, config):
+    return HybridCoreXZKinematics(toolhead, config)