[bindings] Fix bindings for getFrameAcceleration

bindings/python/algorithm/expose-frames.cpp

@@ -69,6 +69,7 @@ namespace pinocchio
     }
     
     BOOST_PYTHON_FUNCTION_OVERLOADS(getFrameVelocity_overload, (&getFrameVelocity<double,0,JointCollectionDefaultTpl>), 3, 4)
+    BOOST_PYTHON_FUNCTION_OVERLOADS(getFrameAcceleration_overload, (&getFrameAcceleration<double,0,JointCollectionDefaultTpl>), 3, 4)
 
     void exposeFramesAlgo()
     {
@@ -95,9 +96,10 @@ namespace pinocchio
 
       bp::def("getFrameAcceleration",
               &getFrameAcceleration<double,0,JointCollectionDefaultTpl>,
-              bp::args("model","data","frame_id"),
-              "Returns the spatial acceleration of the frame expressed in the coordinates system of the Frame itself.\n"
-              "forwardKinematics(model,data,q,v,a) should be called first to compute the joint spatial acceleration stored in data.a .");
+              getFrameAcceleration_overload(
+                bp::args("model","data","frame_id","reference_frame"),
+                "Returns the spatial acceleration of the frame expressed in the coordinate system given by reference_frame.\n"
+                "forwardKinematics(model,data,q,v,a) should be called first to compute the joint spatial acceleration stored in data.a ."));
       
       bp::def("framesForwardKinematics",
               &framesForwardKinematics<double,0,JointCollectionDefaultTpl,VectorXd>,

unittest/python/bindings_frame.py

@@ -63,5 +63,14 @@ class TestFrameBindings(PinocchioTestCase):
         v = pin.getFrameVelocity(self.model, data, self.frame_idx, pin.ReferenceFrame.LOCAL_WORLD_ALIGNED)
         self.assertApprox(v, pin.SE3(T.rotation, np.zeros(3)).act(self.frame_placement.actInv(data.v[self.parent_idx])))
 
+        a = pin.getFrameAcceleration(self.model, data, self.frame_idx)
+        self.assertApprox(a, self.frame_placement.actInv(data.a[self.parent_idx]))
+        a = pin.getFrameAcceleration(self.model, data, self.frame_idx, pin.ReferenceFrame.LOCAL)
+        self.assertApprox(a, self.frame_placement.actInv(data.a[self.parent_idx]))
+        a = pin.getFrameAcceleration(self.model, data, self.frame_idx, pin.ReferenceFrame.WORLD)
+        self.assertApprox(a, data.oMi[self.parent_idx].act(data.a[self.parent_idx]))
+        a = pin.getFrameAcceleration(self.model, data, self.frame_idx, pin.ReferenceFrame.LOCAL_WORLD_ALIGNED)
+        self.assertApprox(a, pin.SE3(T.rotation, np.zeros(3)).act(self.frame_placement.actInv(data.a[self.parent_idx])))
+
 if __name__ == '__main__':
     unittest.main()