diff --git a/include/imu/factor/factor_imu2d.h b/include/imu/factor/factor_imu2d.h
index dff3747be1170845cd95dea4442881655fa8775a..4e9be3689c49fbfedda19f69b3c1bf0139e1604c 100644
--- a/include/imu/factor/factor_imu2d.h
+++ b/include/imu/factor/factor_imu2d.h
@@ -20,18 +20,13 @@ class FactorImu2d : public FactorAutodiff<FactorImu2d, 8, 2, 1, 2, 3, 2, 1, 2, 3
 {
     public:
         FactorImu2d(const FeatureImu2dPtr& _ftr_ptr,
-                  const CaptureImuPtr& _capture_origin_ptr,
-                  const ProcessorBasePtr& _processor_ptr,
-                  bool _apply_loss_function,
-                  FactorStatus _status = FAC_ACTIVE);
+                    const CaptureImuPtr& _capture_origin_ptr,
+                    const ProcessorBasePtr& _processor_ptr,
+                    bool _apply_loss_function,
+                    FactorStatus _status = FAC_ACTIVE);
 
         ~FactorImu2d() override = default;
 
-        std::string getTopology() const override
-        {
-            return std::string("MOTION");
-        }
-
         /** \brief : compute the residual from the state blocks being iterated by the solver.
             -> computes the expected measurement
             -> corrects actual measurement with new bias
@@ -97,12 +92,13 @@ class FactorImu2d : public FactorAutodiff<FactorImu2d, 8, 2, 1, 2, 3, 2, 1, 2, 3
 ///////////////////// IMPLEMENTAITON ////////////////////////////
 
 inline FactorImu2d::FactorImu2d(const FeatureImu2dPtr&    _ftr_ptr,
-                            const CaptureImuPtr&    _cap_origin_ptr,
-                            const ProcessorBasePtr& _processor_ptr,
-                            bool                    _apply_loss_function,
-                            FactorStatus        _status) :
+                                const CaptureImuPtr&    _cap_origin_ptr,
+                                const ProcessorBasePtr& _processor_ptr,
+                                bool                    _apply_loss_function,
+                                FactorStatus        _status) :
                 FactorAutodiff<FactorImu2d, 8, 2, 1, 2, 3, 2, 1, 2, 3>( // ...
                         "FactorImu2d",
+                        TOP_MOTION,
                         _ftr_ptr,
                         _cap_origin_ptr->getFrame(),
                         _cap_origin_ptr,