Update Ros2ControlSystem.cpp: correct joint.acceleration (#1023)

* Update Ros2ControlSystem.cpp: correct acceleration

* Update webots_ros2_control/CHANGELOG.rst

Author: onionsflying

webots_ros2_control/CHANGELOG.rst

@@ -5,6 +5,7 @@ Changelog for package webots_ros2_control
 2023.1.3 (2024-08-07)
 ------------------
 * Added support for the new `ros2_control` API affecting resource_manager and controller_manager.
+* Corrected the sign of the joint accelerations.
 
 2023.1.0 (2023-06-29)
 ------------------

webots_ros2_control/src/Ros2ControlSystem.cpp

@@ -153,7 +153,7 @@ namespace webots_ros2_control {
         const double velocity = std::isnan(joint.position) ? NAN : (position - joint.position) / deltaTime;
 
         if (!std::isnan(joint.velocity))
-          joint.acceleration = (joint.velocity - velocity) / deltaTime;
+          joint.acceleration = (velocity - joint.velocity) / deltaTime;
         joint.velocity = velocity;
         joint.position = position;
       }