corexy: Initial corexy kinematic implementation

Add initial support for corexy kinematics.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 164 insertions, 0 deletions

diff --git a/klippy/corexy.py b/klippy/corexy.py
new file mode 100644
index 00000000..f8b2a052
--- /dev/null
+++ b/klippy/corexy.py
@@ -0,0 +1,164 @@
+# Code for handling the kinematics of corexy robots
+#
+# Copyright (C) 2017  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+import logging
+import stepper, homing
+
+StepList = (0, 1, 2)
+
+class CoreXYKinematics:
+    def __init__(self, printer, config):
+        self.steppers = [stepper.PrinterStepper(
+            printer, config.getsection('stepper_' + n), n)
+                         for n in ['x', 'y', 'z']]
+        self.steppers[0].mcu_endstop.add_stepper(self.steppers[1].mcu_stepper)
+        self.steppers[1].mcu_endstop.add_stepper(self.steppers[0].mcu_stepper)
+        self.max_z_velocity = config.getfloat('max_z_velocity', 9999999.9)
+        self.max_z_accel = config.getfloat('max_z_accel', 9999999.9)
+        self.need_motor_enable = True
+        self.limits = [(1.0, -1.0)] * 3
+    def set_max_jerk(self, max_xy_halt_velocity, max_velocity, max_accel):
+        self.steppers[0].set_max_jerk(max_xy_halt_velocity, max_accel)
+        self.steppers[1].set_max_jerk(max_xy_halt_velocity, max_accel)
+        self.steppers[2].set_max_jerk(0., self.max_z_accel)
+    def set_position(self, newpos):
+        pos = (newpos[0] + newpos[1], newpos[0] - newpos[1], newpos[2])
+        for i in StepList:
+            s = self.steppers[i]
+            if pos[i] >= 0.:
+                steppos = int(pos[i]*s.inv_step_dist + 0.5)
+            else:
+                steppos = int(pos[i]*s.inv_step_dist - 0.5)
+            s.mcu_stepper.set_position(steppos)
+    def home(self, homing_state):
+        # Each axis is homed independently and in order
+        for axis in homing_state.get_axes():
+            s = self.steppers[axis]
+            self.limits[axis] = (s.position_min, s.position_max)
+            # Determine moves
+            if s.homing_positive_dir:
+                pos = s.position_endstop - 1.5*(
+                    s.position_endstop - s.position_min)
+                rpos = s.position_endstop - s.homing_retract_dist
+                r2pos = rpos - s.homing_retract_dist
+            else:
+                pos = s.position_endstop + 1.5*(
+                    s.position_max - s.position_endstop)
+                rpos = s.position_endstop + s.homing_retract_dist
+                r2pos = rpos + s.homing_retract_dist
+            # Initial homing
+            homepos = [None, None, None, None]
+            homepos[axis] = s.position_endstop
+            coord = [None, None, None, None]
+            coord[axis] = pos
+            homing_state.home(list(coord), homepos, [s], s.homing_speed)
+            # Retract
+            coord[axis] = rpos
+            homing_state.retract(list(coord), s.homing_speed)
+            # Home again
+            coord[axis] = r2pos
+            homing_state.home(
+                list(coord), homepos, [s], s.homing_speed/2.0, second_home=True)
+            if axis == 2:
+                # Support endstop phase detection on Z axis
+                coord[axis] = (s.position_endstop
+                               + s.get_homed_offset()*s.step_dist)
+                homing_state.set_homed_position(coord)
+    def motor_off(self, move_time):
+        self.limits = [(1.0, -1.0)] * 3
+        for stepper in self.steppers:
+            stepper.motor_enable(move_time, 0)
+        self.need_motor_enable = True
+    def _check_motor_enable(self, move_time, move):
+        if move.axes_d[0] or move.axes_d[1]:
+            self.steppers[0].motor_enable(move_time, 1)
+            self.steppers[1].motor_enable(move_time, 1)
+        if move.axes_d[2]:
+            self.steppers[2].motor_enable(move_time, 1)
+        need_motor_enable = False
+        for i in StepList:
+            need_motor_enable |= self.steppers[i].need_motor_enable
+        self.need_motor_enable = need_motor_enable
+    def query_endstops(self, print_time):
+        endstops = [(s, s.query_endstop(print_time)) for s in self.steppers]
+        return [(s.name, es.query_endstop_wait()) for s, es in endstops]
+    def _check_endstops(self, move):
+        end_pos = move.end_pos
+        for i in StepList:
+            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 homing.EndstopMoveError(
+                        end_pos, "Must home axis first")
+                raise homing.EndstopMoveError(end_pos)
+    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 move(self, move_time, move):
+        if self.need_motor_enable:
+            self._check_motor_enable(move_time, move)
+        inv_accel = 1. / move.accel
+        inv_cruise_v = 1. / move.cruise_v
+        sxp = move.start_pos[0]
+        syp = move.start_pos[1]
+        start_pos = (sxp + syp, sxp - syp, move.start_pos[2])
+        exp = move.end_pos[0]
+        eyp = move.end_pos[1]
+        end_pos = (exp + eyp, exp - eyp, move.start_pos[2])
+        axes_d = (end_pos[0] - start_pos[0], end_pos[1] - start_pos[1],
+                  move.axes_d[2])
+        for i in StepList:
+            if not axes_d[i]:
+                continue
+            mcu_stepper = self.steppers[i].mcu_stepper
+            mcu_time = mcu_stepper.print_to_mcu_time(move_time)
+            step_pos = mcu_stepper.commanded_position
+            inv_step_dist = self.steppers[i].inv_step_dist
+            step_offset = step_pos - start_pos[i] * inv_step_dist
+            steps = axes_d[i] * inv_step_dist
+            move_step_d = move.move_d / abs(steps)
+
+            # Acceleration steps
+            accel_multiplier = 2.0 * move_step_d * inv_accel
+            if move.accel_r:
+                #t = sqrt(2*pos/accel + (start_v/accel)**2) - start_v/accel
+                accel_time_offset = move.start_v * inv_accel
+                accel_sqrt_offset = accel_time_offset**2
+                accel_steps = move.accel_r * steps
+                count = mcu_stepper.step_sqrt(
+                    mcu_time - accel_time_offset, accel_steps, step_offset
+                    , accel_sqrt_offset, accel_multiplier)
+                step_offset += count - accel_steps
+                mcu_time += move.accel_t
+            # Cruising steps
+            if move.cruise_r:
+                #t = pos/cruise_v
+                cruise_multiplier = move_step_d * inv_cruise_v
+                cruise_steps = move.cruise_r * steps
+                count = mcu_stepper.step_factor(
+                    mcu_time, cruise_steps, step_offset, cruise_multiplier)
+                step_offset += count - cruise_steps
+                mcu_time += move.cruise_t
+            # Deceleration steps
+            if move.decel_r:
+                #t = cruise_v/accel - sqrt((cruise_v/accel)**2 - 2*pos/accel)
+                decel_time_offset = move.cruise_v * inv_accel
+                decel_sqrt_offset = decel_time_offset**2
+                decel_steps = move.decel_r * steps
+                count = mcu_stepper.step_sqrt(
+                    mcu_time + decel_time_offset, decel_steps, step_offset
+                    , decel_sqrt_offset, -accel_multiplier)