Hello,

I know there are many questions about this error specifically but I dont find a solution when it comes to use a custom controller: I created my custom controller with PID parameters to tune (the logic is that I want to do some tests before I change some parameters). Here is my config file:

rrbot: jointstatecontroller: type: jointstatecontroller/JointStateController publish_rate: 50

  joint_position_controller:
    type: my_position_controller/MyJointPositionController
    joint:
        - joint1
        - joint2
    kp: 
      - 10
      - 10
    kd: 
      - 1
      - 1
    ki: 
      - 0.1
      - 0.1

mypositioncontroller/MyJointPositionController is using a positionjointinterface and the idea is to use my own gain parameters to configure the position control. This is the code of the update loop into the control.cpp

void MyJointPositionController::update(const ros::Time& time,
                                            const ros::Duration& period) {
  delta_time += period;
  std::array<double, 2> Out_{};

  for (size_t i = 0; i < 2; ++i) {
    // compute position error
      current_pos_[i] = position_joint_handles_[i].getPosition();
      errorpos_[i] = command_position_[i] - current_pos_[i];

      // P term
      P_[i] = (errorpos_[i] * kp_[i]);

      // I term
      integral_[i] = integral_[i] + (errorpos_[i] * delta_time.toSec());
      I_[i] = ki_[i] * integral_[i];

      //D term
      derivative_[i] = errorpos_[i] / delta_time.toSec();
      D_[i] = kd_[i] * derivative_[i];

      Out_[i] = P_[i] + I_[i] + D_[i];

      position_joint_handles_[i].setCommand(Out_[i]);
  }
}

where kp, kd and ki_ were declared in the initialization of the class.

My problem is, I launch my robot into gazebo (only the robot, not the controllers) and this error appears:

[ERROR] [1675072396.556337077, 0.170000000]: No p gain specified for pid.  Namespace: /rrbot/gazebo_ros_control/pid_gains/joint1
[ERROR] [1675072396.556816165, 0.170000000]: No p gain specified for pid.  Namespace: /rrbot/gazebo_ros_control/pid_gains/joint2

I have seen here that is not an actual error rather than a warning and if no PID gains are found gazebo will control my robot with "joint->SetAngle() or // joint->SetParam("vel") to control the joint."

There is a way to say gazebo not to use anything? like leave the robot with no controllers until I load my own controller? Cause if try to load my own controller I have the following error and I dont know if this is realted to the previous one:

WARN] [1675071221.798537, 21.885000]: Controller Spawner error while taking down controllers: unable to connect to service: [Errno 111] Connection refused
[rrbot/controller_spawner-1] process has died [pid 17418, exit code 1, cmd /opt/ros/noetic/lib/controller_manager/spawner joint_state_controller joint_position_controller __name:=controller_spawner __log:=/home/mikel/.ros/log/fef4f1fa-a080-11ed-9a6b-354ed0b55da0/rrbot-controller_spawner-1.log].
log file: /home/mikel/.ros/log/fef4f1fa-a080-11ed-9a6b-354ed0b55da0/rrbot-controller_spawner-1*.log

Hope can someone throw me light on this issue cause I dont understand my second error and I'm stuck.

Thanks in advance!