bed_tilt: Add support for automatic bed tilt move transformation

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

klippy/extras/bed_tilt.py

@@ -0,0 +1,95 @@
+# Bed tilt compensation
+#
+# Copyright (C) 2018  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+import logging
+import probe
+
+class BedTilt:
+    def __init__(self, config):
+        self.printer = config.get_printer()
+        self.x_adjust = config.getfloat('x_adjust', 0.)
+        self.y_adjust = config.getfloat('y_adjust', 0.)
+        if config.get('points', None) is not None:
+            BedTiltCalibrate(config, self)
+        self.toolhead = None
+        gcode = self.printer.lookup_object('gcode')
+        gcode.set_move_transform(self)
+    def printer_state(self, state):
+        if state == 'connect':
+            self.toolhead = self.printer.lookup_object('toolhead')
+    def get_position(self):
+        x, y, z, e = self.toolhead.get_position()
+        return [x, y, z - x*self.x_adjust - y*self.y_adjust, e]
+    def move(self, newpos, speed):
+        x, y, z, e = newpos
+        self.toolhead.move([x, y, z + x*self.x_adjust + y*self.y_adjust, e],
+                           speed)
+
+# Helper script to calibrate the bed tilt
+class BedTiltCalibrate:
+    def __init__(self, config, bedtilt):
+        self.bedtilt = bedtilt
+        self.printer = config.get_printer()
+        points = config.get('points').split('\n')
+        try:
+            points = [line.split(',', 1) for line in points if line.strip()]
+            self.points = [(float(p[0].strip()), float(p[1].strip()))
+                           for p in points]
+        except:
+            raise config.error("Unable to parse bed tilt points")
+        self.speed = config.getfloat('speed', 50., above=0.)
+        self.horizontal_move_z = config.getfloat('horizontal_move_z', 5.)
+        self.probe_z_offset = config.getfloat('probe_z_offset', 0.)
+        self.manual_probe = config.getboolean('manual_probe', None)
+        if self.manual_probe is None:
+            self.manual_probe = not config.has_section('probe')
+        self.gcode = self.printer.lookup_object('gcode')
+        self.gcode.register_command(
+            'BED_TILT_CALIBRATE', self.cmd_BED_TILT_CALIBRATE,
+            desc=self.cmd_BED_TILT_CALIBRATE_help)
+    cmd_BED_TILT_CALIBRATE_help = "Bed tilt calibration script"
+    def cmd_BED_TILT_CALIBRATE(self, params):
+        self.gcode.run_script("G28")
+        probe.ProbePointsHelper(
+            self.printer, self.points, self.horizontal_move_z,
+            self.speed, self.manual_probe, self)
+    def get_position(self):
+        kin = self.printer.lookup_object('toolhead').get_kinematics()
+        return kin.get_position()
+    def finalize(self, positions):
+        logging.debug("Got: %s", positions)
+        params = { 'x_adjust': self.bedtilt.x_adjust,
+                   'y_adjust': self.bedtilt.y_adjust,
+                   'z_adjust': self.probe_z_offset }
+        logging.debug("Params: %s", params)
+        def adjusted_height(pos, params):
+            x, y, z = pos
+            return (z + x*params['x_adjust'] + y*params['y_adjust']
+                    - params['z_adjust'])
+        def errorfunc(params):
+            total_error = 0.
+            for pos in positions:
+                total_error += adjusted_height(pos, params)**2
+            return total_error
+        new_params = probe.coordinate_descent(params.keys(), params, errorfunc)
+        logging.debug("Got2: %s", new_params)
+        for pos in positions:
+            logging.debug("orig: %s new: %s",
+                          adjusted_height(pos, params),
+                          adjusted_height(pos, new_params))
+        z_warn = ""
+        z_diff = new_params['z_adjust'] - self.probe_z_offset
+        if abs(z_diff) > .010:
+            z_warn = "Note: Z offset was %.6f\n" % (z_diff,)
+        self.gcode.respond_info(
+            "%sx_adjust: %.6f y_adjust: %.6f\n"
+            "To use these parameters, update the printer config file with\n"
+            "the above and then issue a RESTART command" % (
+                z_warn, new_params['x_adjust'], new_params['y_adjust']))
+
+def load_config(config):
+    if config.get_name() != 'bed_tilt':
+        raise config.error("Invalid bed_tilt config name")
+    return BedTilt(config)