diff --git a/cartographer_ros/cartographer_ros/assets_writer.cc b/cartographer_ros/cartographer_ros/assets_writer.cc index 1ca3e09..4f12826 100644 --- a/cartographer_ros/cartographer_ros/assets_writer.cc +++ b/cartographer_ros/cartographer_ros/assets_writer.cc @@ -146,7 +146,7 @@ AssetsWriter::AssetsWriter(const std::string& pose_graph_filename, << "Pose graphs contains " << pose_graph_.trajectory_size() << " trajectories while " << bag_filenames_.size() << " bags were provided. This tool requires one bag for each " - "trajectory in the same order as the correponding trajectories in the " + "trajectory in the same order as the corresponding trajectories in the " "pose graph proto."; // This vector must outlive the pipeline. diff --git a/docs/source/algo_walkthrough.rst b/docs/source/algo_walkthrough.rst index b28622d..512baf0 100644 --- a/docs/source/algo_walkthrough.rst +++ b/docs/source/algo_walkthrough.rst @@ -253,7 +253,7 @@ Scan matching starts by aligning far points of the low resolution point cloud wi Global SLAM ----------- -While the local SLAM generates its succession of submaps, a global optimization (usually refered to as "*the optimization problem*" or "*sparse pose adjustment*") task runs in background. +While the local SLAM generates its succession of submaps, a global optimization (usually referred to as "*the optimization problem*" or "*sparse pose adjustment*") task runs in background. Its role is to re-arrange submaps between each other so that they form a coherent global map. For instance, this optimization is in charge of altering the currently built trajectory to properly align submaps with regards to loop closures. @@ -269,7 +269,7 @@ The optimization is run in batches once a certain number of trajectory nodes was The global SLAM is a kind of "*GraphSLAM*", it is essentially a pose graph optimization which works by building **constraints** between **nodes** and submaps and then optimizing the resulting constraints graph. Constraints can intuitively be thought of as little ropes tying all nodes together. -The sparse pose adjustement fastens those ropes altogether. +The sparse pose adjustment fastens those ropes altogether. The resulting net is called the "*pose graph*". .. note:: diff --git a/docs/source/configuration.rst b/docs/source/configuration.rst index 67a59e0..6607ec9 100644 --- a/docs/source/configuration.rst +++ b/docs/source/configuration.rst @@ -69,7 +69,7 @@ use_nav_sat use_landmarks If enabled, subscribes to `cartographer_ros_msgs/LandmarkList`_ on the topic "landmarks". Landmarks must be provided, as `cartographer_ros_msgs/LandmarkEntry`_ within `cartographer_ros_msgs/LandmarkList`_. If `cartographer_ros_msgs/LandmarkEntry`_ data is provided the information - will be included in the SLAM accoding to the ID of the `cartographer_ros_msgs/LandmarkEntry`_. The `cartographer_ros_msgs/LandmarkList`_ should be provided at a sample rate comparable to the other sensors. The list can be empty but has to be provided because Cartographer strictly time orders sensor data in order to make the landmarks deterministic. However it is possible to set the trajectory builder option "collate_landmarks" to false and allow for a non-deterministic but also non-blocking approach. + will be included in the SLAM according to the ID of the `cartographer_ros_msgs/LandmarkEntry`_. The `cartographer_ros_msgs/LandmarkList`_ should be provided at a sample rate comparable to the other sensors. The list can be empty but has to be provided because Cartographer strictly time orders sensor data in order to make the landmarks deterministic. However it is possible to set the trajectory builder option "collate_landmarks" to false and allow for a non-deterministic but also non-blocking approach. num_laser_scans Number of laser scan topics to subscribe to. Subscribes to diff --git a/docs/source/going_further.rst b/docs/source/going_further.rst index 3e94757..ed824d2 100644 --- a/docs/source/going_further.rst +++ b/docs/source/going_further.rst @@ -66,7 +66,7 @@ You can then use Cartographer as part of your calibration process to improve the Multi-trajectories SLAM ======================= -Cartographer can perform SLAM from multiple robots emiting data in parallel. +Cartographer can perform SLAM from multiple robots emitting data in parallel. The global SLAM is able to detect shared paths and will merge the maps built by the different robots as soon as it becomes possible. This is achieved through the usage of two ROS services ``start_trajectory`` and ``finish_trajectory``. (refer to the ROS API reference documentation for more details on their usage)