[JTC] Remove start_with_holding option (ros-controls#839)

Author: christophfroehlich

joint_trajectory_controller/src/joint_trajectory_controller.cpp

@@ -944,11 +944,8 @@ controller_interface::CallbackReturn JointTrajectoryController::on_activate(
     read_state_from_state_interfaces(last_commanded_state_);
   }
 
-  // Should the controller start by holding position at the beginning of active state?
-  if (params_.start_with_holding)
-  {
-    add_new_trajectory_msg(set_hold_position());
-  }
+  // The controller should start by holding position at the beginning of active state
+  add_new_trajectory_msg(set_hold_position());
   rt_is_holding_.writeFromNonRT(true);
 
   // parse timeout parameter

joint_trajectory_controller/src/joint_trajectory_controller_parameters.yaml

@@ -73,11 +73,6 @@ joint_trajectory_controller:
       one_of<>: [["splines", "none"]],
     }
   }
-  start_with_holding: {
-    type: bool,
-    default_value: true,
-    description: "If true, start with holding position after activation. Otherwise, no command will be sent until the first trajectory is received.",
-  }
   allow_nonzero_velocity_at_trajectory_end: {
     type: bool,
     default_value: false,

joint_trajectory_controller/test/test_trajectory_controller.cpp

@@ -444,37 +444,18 @@ TEST_P(TrajectoryControllerTestParameterized, update_dynamic_tolerances)
   executor.cancel();
 }
 
-/**
- * @brief check if hold on startup is deactivated
- */
-TEST_P(TrajectoryControllerTestParameterized, no_hold_on_startup)
-{
-  rclcpp::executors::MultiThreadedExecutor executor;
-
-  rclcpp::Parameter start_with_holding_parameter("start_with_holding", false);
-  SetUpAndActivateTrajectoryController(executor, {start_with_holding_parameter});
-
-  constexpr auto FIRST_POINT_TIME = std::chrono::milliseconds(250);
-  updateControllerAsync(rclcpp::Duration(FIRST_POINT_TIME));
-  // after startup without start_with_holding being set, we expect no active trajectory
-  ASSERT_FALSE(traj_controller_->has_active_traj());
-
-  executor.cancel();
-}
-
 /**
  * @brief check if hold on startup
  */
 TEST_P(TrajectoryControllerTestParameterized, hold_on_startup)
 {
   rclcpp::executors::MultiThreadedExecutor executor;
 
-  rclcpp::Parameter start_with_holding_parameter("start_with_holding", true);
-  SetUpAndActivateTrajectoryController(executor, {start_with_holding_parameter});
+  SetUpAndActivateTrajectoryController(executor, {});
 
   constexpr auto FIRST_POINT_TIME = std::chrono::milliseconds(250);
   updateControllerAsync(rclcpp::Duration(FIRST_POINT_TIME));
-  // after startup with start_with_holding being set, we expect an active trajectory:
+  // after startup, we expect an active trajectory:
   ASSERT_TRUE(traj_controller_->has_active_traj());
   // one point, being the position at startup
   std::vector<double> initial_positions{INITIAL_POS_JOINT1, INITIAL_POS_JOINT2, INITIAL_POS_JOINT3};