POSIM SeaPressure Plugin

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POSIM — Platform for Ocean Simulation · documentation checked 2026-10-01

Target: ROS 2 Lyrical / Gazebo Jetty. Current source. Compatibility names such as dave_* are intentional. Start with POSIM Installation and POSIM Quickstart & Backend Support.

Source documentation and inherited illustrations do not certify every runtime configuration. Published Docker candidates, development main, and experimental WGPU are distinct states.

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Before the examples, source ROS and the matching workspace using POSIM Native Installation or POSIM Docker Guide. Commands containing ~/posim_ws below refer to a native source workspace; in a prebuilt container use its documented $POSIM_WS/install/setup.bash instead. Existing illustrations are retained from the DAVE documentation and are not new POSIM runtime captures.

🪼Overview

The Subsea Pressure Sensor Plugin is a simulation plugin designed to simulate the behavior of a subsea pressure sensor within a Gazebo simulation environment. The plugin integrates with Gazebo, using the Gazebo and ROS 2 interfaces to publish simulated sensor data. This documentation outlines the purpose of the plugin, its parameters, and its operational workflow.

🕸️Parameters Summary Table -

SDF parameters and an internal variance setting are listed below. noiseSigma is an internal constant in this implementation, not an accepted SDF tag; <noise_sigma> is not parsed.

Parameters	Default Values	Notes
`saturation`	3000	Maximum output pressure. POSIM `main` parses this value but does not yet enforce the upper limit.
`estimate_depth_on`	true	A boolean flag indicating whether to estimate depth based on the pressure measurement. If set to true, the plugin calculates the depth of the sensor based on the pressure readings.
`standard_pressure`	101.325	Internal model parameter in kPa, used as the surface reference for pressure and depth calculations. POSIM converts the computed value to Pa before publishing.
`kPa_per_meter`	9.80638	The conversion factor from depth (in meters) to pressure (in kilopascals). This parameter defines how pressure changes with depth in the simulated environment.
`noiseSigma` (internal)	3.0	Sets the published variance. POSIM `main` does not inject Gaussian noise into the pressure value.

Operation

configure - During the configuration phase, the plugin initializes its parameters based on the values specified in the SDF file. It creates the necessary publishers for publishing sensor data via ROS 2 and, optionally, Gazebo messages.
PreUpdate - Retrieves the sensor pose, clamps above-surface depth to zero, and calculates pressure. noiseSigma currently affects the published variance only.
PostUpdate - Publishes ROS 2 and Gazebo messages at the configured <update_rate>.

How to use the Plugin -

1.XML Parameters -

First you would need to add the following lines to your sdf file-

<!-- Sea Pressure Sensor Plugin -->
<plugin
  filename="sea_pressure_sensor"
  name="dave_gz_sensor_plugins::SubseaPressureSensorPlugin">
  <namespace>rexrov</namespace>
  <topic>sea_pressure</topic>
  <update_rate>10.0</update_rate> <!-- omit or use <=0 for every simulation update -->
  <!-- Enable the depth output described below. -->
  <estimate_depth_on>true</estimate_depth_on>
  <standard_pressure>101.325</standard_pressure>
  <kPa_per_meter>9.80638</kPa_per_meter>
</plugin>

kindly don’t forget to replace the namespace tag with your model name.

2. Shell command

The SeaPressure plugin is launched through the existing dave_demos dave_robot.launch.py; no separate dave_robot_launch package is required.