You signed in with another tab or window. Reload to refresh your session.You signed out in another tab or window. Reload to refresh your session.You switched accounts on another tab or window. Reload to refresh your session.Dismiss alert
Copy file name to clipboardExpand all lines: doc/state_estimation_nodes.rst
+4Lines changed: 4 additions & 0 deletions
Display the source diff
Display the rich diff
Original file line number
Diff line number
Diff line change
@@ -280,6 +280,8 @@ If ``debug`` is *true*, the file to which debug output is written.
280
280
^^^^^^^^^^^^^^^^^^^^^^^^^
281
281
The process noise covariance, commonly denoted *Q*, is used to model uncertainty in the prediction stage of the filtering algorithms. It can be difficult to tune, and has been exposed as a parameter for easier customization. This parameter can be left alone, but you will achieve superior results by tuning it. In general, the larger the value for *Q* relative to the variance for a given variable in an input message, the faster the filter will converge to the value in the measurement.
282
282
283
+
Specifying the full covariance matrix is supported, but can be cumbersome. For that reason, this parameter can also be used to simply specify the diagonal values. In that event, all off-diagonal values will be set to 0.
284
+
283
285
~dynamic_process_noise_covariance
284
286
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
285
287
If *true*, will dynamically scale the ``process_noise_covariance`` based on the robot's velocity. This is useful, e.g., when you want your robot's estimate error covariance to stop growing when the robot is stationary. Defaults to *false*.
@@ -288,6 +290,8 @@ If *true*, will dynamically scale the ``process_noise_covariance`` based on the
288
290
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
289
291
The estimate covariance, commonly denoted *P*, defines the error in the current state estimate. The parameter allows users to set the initial value for the matrix, which will affect how quickly the filter converges. For example, if users set the value at position :math:`[0, 0]` to a very small value, e.g., `1e-12`, and then attempt to fuse measurements of X position with a high variance value for :math:`X`, then the filter will be very slow to "trust" those measurements, and the time required for convergence will increase. Again, users should take care with this parameter. When only fusing velocity data (e.g., no absolute pose information), users will likely *not* want to set the initial covariance values for the absolute pose variables to large numbers. This is because those errors are going to grow without bound (owing to the lack of absolute pose measurements to reduce the error), and starting them with large values will not benefit the state estimate.
290
292
293
+
Specifying the full covariance matrix is supported, but can be cumbersome. For that reason, this parameter can also be used to simply specify the diagonal values. In that event, all off-diagonal values will be set to 0.
294
+
291
295
~reset_on_time_jump
292
296
^^^^^^^^^^^^^^^^^^^
293
297
If set to *true* and ``ros::Time::isSimTime()`` is *true*, the filter will reset to its uninitialized state when a jump back in time is detected on a topic. This is useful when working with bag data, in that the bag can be restarted without restarting the node.
0 commit comments