Change parameter description.

Fix linting

Signed-off-by: Chanh Hoang <chanhhoang999x@gmail.com>

Author: chanhhoang99

nav2_mppi_controller/README.md

@@ -61,8 +61,7 @@ This process is then repeated a number of times and returns a converged solution
  | publish_optimal_trajectory | bool   | Publishes the full optimal trajectory sequence each control iteration for downstream  control systems, collision checkers, etc to have context beyond the next timestep. |
  | publish_critics_stats      | bool   | Default false. Whether to publish statistics about each critic's performance. When enabled, publishes a `nav2_msgs::msg::CriticsStats` message containing critic names, whether they changed costs, and the sum of costs added by each critic. Useful for debugging and tuning critic behavior. |
 
- | open_loop        | bool    | Default false. It is unavoidable that it takes time for motors to reach a specific setpoint. Espescially, in case where acceleration and model_dt are small. The velocity steps (example 0.0 -> 0.025 -> 0.05 -> 0.075 ...) are also tight. Hence, torque generated by motor is very little and it's hard to move the motor. For instance, MPPI is running with model_dt=0.05, this means MPPI will get odometry every 50ms .But at 50ms, the motor has not yet reach it setpoint (at that time the torque generated my motor is not strong enough). When close loop mode is used, MPPI will get the current odometry and add small velocity step for next setpoint every control iteration. Because of that, motor still could not generate enough torque.
- When open_loop is used, MPPI uses last command velocity instead of odometry, this helps small velocity steps accumulate every control iteration and at some point, it will be enough to populate the motor.
+ | open_loop        | bool    | Default false. Useful when using low accelerations and when wheel odometry's latency causes issues in initial state estimation. |
 
 #### Trajectory Visualizer
  | Parameter             | Type   | Definition                                                                                                  |

nav2_mppi_controller/include/nav2_mppi_controller/models/optimizer_settings.hpp

@@ -38,7 +38,7 @@ struct OptimizerSettings
   unsigned int iteration_count{0u};
   bool shift_control_sequence{false};
   size_t retry_attempt_limit{0};
-  bool open_loop;
+  bool open_loop{false};
 };
 
 }  // namespace mppi::models

nav2_mppi_controller/src/optimizer.cpp

@@ -352,17 +352,17 @@ void Optimizer::updateInitialStateVelocities(models::State & state) const
 {
   const bool open = settings_.open_loop;
 
-  const float vx0 = open ? control_sequence_.vx(0)
-                         : static_cast<float>(state.speed.linear.x);
-  const float wz0 = open ? control_sequence_.wz(0)
-                         : static_cast<float>(state.speed.angular.z);
+  const float vx0 = open ? control_sequence_.vx(0) :
+    static_cast<float>(state.speed.linear.x);
+  const float wz0 = open ? control_sequence_.wz(0) :
+    static_cast<float>(state.speed.angular.z);
 
   state.vx.col(0) = vx0;
   state.wz.col(0) = wz0;
 
   if (isHolonomic()) {
-    const float vy0 = open ? control_sequence_.vy(0)
-                           : static_cast<float>(state.speed.linear.y);
+    const float vy0 = open ? control_sequence_.vy(0) :
+      static_cast<float>(state.speed.linear.y);
     state.vy.col(0) = vy0;
   }
 }