* add tab2 controller

id11/__init__.py

+# -*- coding: utf-8 -*-
+
+"""Top-level package for ID11 project."""
+
+__author__ = """BCU Team"""
+__email__ = "papillon@esrf.fr"
+__version__ = "0.1.0"
+

id11/controllers/tab2.py

+# -*- coding: utf-8 -*-
+#
+# This file is part of the bliss project
+#
+# Copyright (c) 2016 Beamline Control Unit, ESRF
+# Distributed under the GNU LGPLv3. See LICENSE for more info.
+
+import numpy as np
+from bliss.controllers.motor import CalcController
+
+"""
+2 legs system
+=============
+
+   (x)<---------------------------------------
+              -                         -
+              |               [dcenter] |
+              |          (C)<---------->|
+              |<----------------------->|
+              |        [dlegs]          |
+              +                         +
+            back                      front
+
+Configurations:
+
+* [front] and [back] are two linear translation moving in same direction along y-axis
+* [dlegs] is the distance between the two legs (always >0)
+* [dcenter] define the center of rotation:
+  - it can be on left of front leg [dcenter > 0]
+  - it can be on right of front leg [dcenter < 0]
+* [dlegs], [dcenter] are of same units as [front] and [back] motors
+  which are supposed to have the same units
+* [trans] is the calulated y-axis translation of point (C) 
+* [rot] is the calculated z-axis rotation 
+  default unit of [rot] is mrad. It can be changed to deg or rad
+  by setting unit config parameter
+
+Example:
+
+controller:
+    class: tab2
+    module: tables
+    dlegs: 200
+    dcenter: 100
+    axes:
+        - name: $tf
+          tags: real front
+        - name: $tb
+          tags: real back
+        - name: tz
+          tags: trans
+        - name: tr
+          tags: rot
+          unit: deg [optionnal, default=mrad]
+"""
+
+
+class Tab2(CalcController):
+    def initialize(self):
+        CalcController.initialize(self)
+        self._d = self.config.get("dlegs", float)
+        self._dc = self.config.get("dcenter", float)
+        self.__rot_unit = "mrad"
+
+    def initialize_axis(self, axis):
+        if axis.config.get("tags") == "rot":
+            rot_unit = axis.config.get("unit", str, None)
+            if rot_unit is None:
+                axis.config.set("unit", self.__rot_unit)
+            else:
+                self.__rot_unit = rot_unit
+        if axis.config.get("tags") == "trans":
+            tr_unit = axis.config.get("unit", str, None)
+            if tr_unit is None:
+                front_unit = self._tagged["front"][0].unit
+                back_unit = self._tagged["back"][0].unit
+                if front_unit == back_unit and front_unit is not None:
+                    axis.config.set("unit", front_unit)
+
+    @property
+    def center(self):
+        return self._dc
+
+    @center.setter
+    def center(self, new_dc):
+        self._dc = new_dc
+        self._real_position_update()
+
+    def calc_from_real(self, positions_dict):
+        tf = positions_dict["front"]
+        tb = positions_dict["back"]
+        d = self._d
+        dc = self._dc
+
+        rot = np.arctan((tb - tf) / d)
+        trans = tf + dc * ((tb - tf) / d)
+
+        if self.__rot_unit == "deg":
+            rot = np.degrees(rot)
+        elif self.__rot_unit == "mrad":
+            rot *= 1000.0
+
+        return {"rot": rot, "trans": trans}
+
+    def calc_to_real(self, positions_dict):
+        th = positions_dict["trans"]
+        tr = positions_dict["rot"]
+        d = self._d
+        dc = self._dc
+
+        if self.__rot_unit == "deg":
+            tr = np.radians(tr)
+        elif self.__rot_unit == "mrad":
+            tr /= 1000.0
+
+        front = th - dc * np.tan(tr)
+        back = th + (d - dc) * np.tan(tr)
+
+        return {"front": front, "back": back}