Added initial estimator stucture and overview.

docs/developer-guide/rosplane/controller/controller-general-overview.md

@@ -83,7 +83,7 @@ A table of arguments and parameter files that work out of the box is given in th
 !!! note 
     Filepaths will need to be altered to work.
 !!! note
-    The most common way of running the controller is in through a launch file with the rest of the ROSplane pipeline running as well.
+    The most common way of running the controller is through a launch file with the rest of the ROSplane pipeline running as well.
     See the ROSplane Overview in the Developer and User Guides for more details.
 
 

docs/developer-guide/rosplane/estimator/estimator-base.md

@@ -0,0 +1,28 @@
+# Estimator Base
+
+## Overview
+
+The estimator base implements the basic ROS interfaces for the estimator.
+This includes setting up subscribers, publishers and initializing parameter management.
+The idea of the base class, is that all interfacing with ROS and shared resources across all inheritance levels happens or are contained in this class.
+
+## ROS Interfaces
+
+The estimator has the following ROS interfaces.
+
+| ![Diagram of Estimator ROS Sensors](../../../assets/estimator_assets/estimator_ros_input_output.png "Estimator ROS Sensors") |
+|:--:|
+|*Figure 1: Estimator's ROS interactions.*|
+
+The estimator has several ROS interfaces that are tracked as member variables of the `estimator_base` class.
+They are summarized in the table below:
+
+| ROS Interface | Topic | Explanation | Message Type |
+|:------:|:-------:| :---: | :---: |
+| <div style="white-space: nowrap;">`vehicle_state_pub_`<div> | `/estimated_state` | Publishes the estimated state of teh vehicle. | State.msg |
+| <div style="white-space: nowrap;">`gnss_fix_sub_`<div> | `/navsat_compat/fix` | Subcribes to the GNSS position information. | NavSatFix.msg |
+| <div style="white-space: nowrap;">`gnss_vel_sub_`<div> | `/navsat_compat/vel` | Subcribes to the GNSS velocity information. | TwistStamped.msg |
+| <div style="white-space: nowrap;">`imu_sub_`<div> | `/imu/data` | Subcribes to the IMU data (both Gyro and Accel). | Imu.msg |
+| <div style="white-space: nowrap;">`baro_sub_`<div> | `/baro` | Subcribes to the barometer pressure information. | Barometer.msg |
+| <div style="white-space: nowrap;">`airspeed_sub_`<div> | `/airspeed` | Subcribes to the differential pressure information. | Airspeed.msg |
+| <div style="white-space: nowrap;">`status_sub_`<div> | `/status` | Subcribes to the aircraft status information. | Status.msg |

docs/developer-guide/rosplane/estimator/estimator-overview.md

@@ -0,0 +1,95 @@
+# Estimator Overview
+
+## Overview
+
+The estimator is a continuous-discrete Kalman Filter, a full treatment of the filter is found in section 8.5 of the [UAV book](https://github.com/randybeard/mavsim_public).
+This filter essentially works by inverting a few sensor models and then using a two stage estimation of first the attitude and then the position state values.
+This page will outline the states, their meaning and any general notes on the states.
+For a more in depth look at which states are estimated in which way visit the [Estimator Base](./estimator-base.md) and [Estimator Example](./estimator-example.md) pages.
+
+## ROS Interactions
+
+The estimator takes in sensor information from `rosflight_io` computes an estimate and publishes it to the rest of ROSplane.
+
+
+| ![Diagram of Estimator ROS Interactions](../../../assets/estimator_assets/estimator_ros_input_output.png "Diagram of Estimator ROS Interactions") |
+|:--:|
+|*Figure 1: ROS network interactions for the estimator.*|
+
+### Input
+
+The inputs to the estimator are, accelerometer, rate gyro, barometer, differential pressure, GPS position, and GPS velocity estimates.
+The table with the topic for each of the measures is below.
+
+| Measure | Explanation | Topic |
+|:------:|:-------:| :---: |
+| Accelerometer | This measures the specfic force applied to the aircraft in the body frame axes (see section 7.1 in the UAV book for more details). | `/imu/data/linear_acceleration` |
+| Rate Gyro | This measures the angular velocity of the aircraft around the body frame axes. | `/imu/data/angular_velocity` |
+| Barometer | The barometer measures the ambient air pressure. It is calibrated on arm to establish a "zero" altitude measurement. | `/baro/pressure` |
+| Differential Pressure | The differential pressure sensor, measures the difference in pressure using a pitot tube due to forward velocity. | `/airspeed/differential_pressure` |
+| GNSS Position | GNSS postion gives the position of the aircraft in latitude, longitude and altitude. | `/navsat_compat/fix` |
+| GNSS Velocity | GNSS velocity gives the velocity of the aircraft in meters per second in the global NED frame. | `/navsat_compat/vel` |
+| Status | Indicates whether the aircraft is armed (indicating a need to initialized position and altitude estimates). | `/status` |
+
+These topics provide the measures that are fused to create a state estimate.
+
+| ![Diagram of Estimator ROS IO](../../../assets/estimator_assets/estimator_ros_input_output.png "Diagram of Estimator ROS IO") |
+|:--:|
+|*Figure 1: ROS topic subscriptions and publications for the estimator.*|
+
+## Output
+
+Their are 20 states estimated by the estimator that are published to the rest of ROSplane.
+These states cover the position, orientation and aerodynamic information for the aircraft.
+There are more than 20 states listed in the following table, but this is because either Euler angles or quaternions can be used to express orientation.
+Below is a table of the `/estimated_state` message and what each of the fields represents.
+See the Frames and Derivation page for more information, or chapter 2 of the [UAV book](https://github.com/randybeard/mavsim_public).
+
+| State | Explanation | Range/Type/Units |
+|:--:|:--:|:--:|
+| postion[3] | A 3 vector of the NED position of the aircraft. | $(-\infty , \infty)$ (float)(meters) |
+| va | The airspeed of the aircraft. Always positive because it is the magnitude. | $(0 , \infty)$ (float)(meters/second) |
+| alpha | The angle of attack of the aircraft wing. | $(-\pi, \pi)$ (float)(radians) |
+| beta | The side-slip angle of the aircraft. | $(-\pi, \pi)$ (float)(radians) |
+| phi | The roll angle of the aircraft. | $(-\pi, \pi)$ (float)(radians) |
+| theta | The pitch angle of the aircraft. | $(-\pi, \pi)$ (float)(radians) |
+| psi | The yaw angle of the aircraft. | $(-\pi, \pi)$ (float)(radians) |
+| chi | The course angle of the aircraft. | $(-\pi, \pi)$ (float)(radians) |
+| u | The velocity in the body x axis. | $(-\infty, \infty)$ (float)(meters/second) |
+| v | The velocity in the body y axis. | $(-\infty, \infty)$ (float)(meters/second) |
+| w | The velocity in the body z axis. | $(-\infty, \infty)$ (float)(meters/second) |
+| p | The angular velocity about the body x axis (rollrate). | $(-\infty, \infty)$ (float)(radians/second) |
+| q | The angular velocity about the body y axis (pitchrate). | $(-\infty, \infty)$ (float)(radians/second) |
+| r | The angular velocity about the body z axis (yawrate). | $(-\infty, \infty)$ (float)(radians/second) |
+| vg | The groundspeed of the aircraft. Always positive because it is the magnitude. | $(0 , \infty)$ (float)(meters/second) |
+| wn | The global north velocity of the wind. | $(-\infty , \infty)$ (float)(meters/second) |
+| we | The global east velocity of the wind. | $(-\infty , \infty)$ (float)(meters/second) |
+| _ | **The following entries are optional.** | _ |
+| quat[4] | A 4 vector of the quaternion describing the orientation. | $(-1 , 1)$ (float) |
+| quat_valid | A flag indicating whether the data in the quat entry is valid.| True/False (bool) |
+| psi_deg | The yaw angle of the aircraft in degrees. | $(-180, 180)$ (float)(degrees) |
+| chi_deg | The course angle of the aircraft in degrees. | $(-180, 180)$ (float)(degrees) |
+| init_lat | The latitude of the aircraft when first armed. | $(-90, 90)$ (float)(DDS) |
+| init_long | The longitude of the aircraft when first armed. | $(-180, 180)$ (float)(DDS) |
+| init_alt | The altitude of the aircraft when first armed. | $(0, \infty)$ (float)(meters) |
+
+!!! note 
+    More states may be estimated in the estimator than listed, these states are just those useful to other parts of ROSplane.
+
+## Running the Estimator
+
+The estimator is in the main `rosplane` ROS package.
+The ROS executable is `rosplane_estimator_node`, yielding the run command:
+
+`ros2 run rosplane rosplane_estimator_node`
+
+To pass a set of parameters for the controller from a yaml file using the `--ros-args` option.
+
+`ros2 run rosplane rosplane_estimator_node --ros-args --params-file path/to/params.yaml`
+
+
+!!! note 
+    Filepaths will need to be altered to work.
+!!! note
+    The most common way of running the estimator is through a launch file with the rest of the ROSplane pipeline running as well.
+    See the ROSplane Overview in the Developer and User Guides for more details.

mkdocs.yml

@@ -77,6 +77,10 @@ nav:
         - Controller State Machine: developer-guide/rosplane/controller/controller-state-machine.md
         - Successive Loop Closure Controller Outline: developer-guide/rosplane/controller/controller-outline.md
         - Total Energy Controller: developer-guide/rosplane/controller/controller-total-energy.md
+      - Estimator:
+        - Estimator Overview: developer-guide/rosplane/estimator/estimator-overview.md
+        - Estimator Base: developer-guide/rosplane/estimator/estimator-base.md
+        - Estimator Example: developer-guide/rosplane/estimator/estimator-example.md
       - Parameter Management: developer-guide/rosplane/parameter-management.md
       - Path Planning: 
         - Path Planning Overview: developer-guide/rosplane/path-planning/path-planning-overview.md