diff --git a/mujoco_controllers/__init__.py b/mujoco_controllers/__init__.py
index e69de29..dfa047f 100644
--- a/mujoco_controllers/__init__.py
+++ b/mujoco_controllers/__init__.py
@@ -0,0 +1,14 @@
+"""A very basic abstract base class for Mujoco Controller"""
+
+import abc
+
+class MujocoController(abc.ABC):
+    """Abstract class for Mujoco Controller"""
+
+    @abc.abstractmethod
+    def compute_control_output(self):
+        pass
+
+    @abc.abstractmethod
+    def is_converged(self):
+        pass
diff --git a/mujoco_controllers/osc.py b/mujoco_controllers/osc.py
index 03b0670..217ebf8 100644
--- a/mujoco_controllers/osc.py
+++ b/mujoco_controllers/osc.py
@@ -15,7 +15,6 @@
 from mujoco import viewer
 
 from dm_control import composer, mjcf
-from dm_robotics.transformations.transformations import mat_to_quat, quat_to_mat, quat_to_euler
 from dm_robotics.transformations import transformations as tr
 
 from mujoco_controllers.build_env import construct_physics
@@ -71,7 +70,10 @@ def current_eef_position(self):
 
     @property
     def current_eef_quat(self):
-        return mat_to_quat(self.physics.bind(self.eef_site).xmat.reshape(3,3).copy())
+        quat = np.zeros(4,)
+        rot_mat = self.physics.bind(self.eef_site).xmat.copy()
+        mujoco.mju_mat2Quat(quat, rot_mat)
+        return quat
 
     @property
     def current_eef_velocity(self):
@@ -132,13 +134,20 @@ def _orientation_error(
         quat: np.ndarray,
         quat_des: np.ndarray,
     ) -> np.ndarray:
-        quat_err = tr.quat_mul(quat, tr.quat_conj(quat_des))
-        quat_err /= np.linalg.norm(quat_err)
+        
+        quat_conj = np.zeros(4,)
+        mujoco.mju_negQuat(quat_conj, quat_des)
+        quat_conj /= np.linalg.norm(quat_conj)
+
+        quat_err = np.zeros(4,)
+        mujoco.mju_mulQuat(quat_err, quat, quat_conj)
+        
         axis_angle = tr.quat_to_axisangle(quat_err)
         if quat_err[0] < 0.0:
             angle = np.linalg.norm(axis_angle) - 2 * np.pi
         else:
             angle = np.linalg.norm(axis_angle)
+        print(axis_angle * angle)
         return axis_angle * angle
 
     def current_orientation_error(self):
@@ -252,5 +261,5 @@ def is_converged(self):
     
     pre_pick_height = 0.6
     pick_height = 0.15
-    default_quat =  mat_to_quat(R.from_euler('xyz', [0, 180, 0], degrees=True).as_matrix())
+    default_quat = (R.from_euler('xyz', [0, 180, 0], degrees=True).as_matrix()).as_quat()