Using motoman-ros and checking the simulation result on MotoSim

[sahilshembekar]

Hello @gavanderhoorn ,

I have the Yaskawa Motoman GP180 robot which I want to use for handling operation. Since the payload capacity of the robot is large I want to simulate the trajectory on the simulation software MotoSimbefore applying to the real robot.

Our goal is to

1. Use ros industrial API to move the robot based on our code.
2. Simulate the trajectory planning on MotoSim (This environment contains the safety fence and other objects for handling)
3. Once the simulation test is completed, test it on the real robot.

From the documentation Example: starting the streaming interface, I found that for FANUC robot it is possible to simulate the interface streaming on ROBOGUIDE by making the use_bswap:= false.

My question is

1. Is it actually possible to the do the same for MotoSim for Yaskawa motoman robot?
2. If it is possible, I want to know if the value for the robot_ip in the command roslaunch motoman_gp180_support robot_interface_streaming_gp180_120.launch robot_ip:=192.168.x.xx controller:=yrc1000 should be the ipv4 address or the some dummy ip value?
3. If it is not possible, what would you suggest as an alternative to simulate a close to exact scenario before testing on the real robot

System specification:

• Ubuntu 20.04.5 LTS with ros noetic on docker in a windows 11 PC.
• MotoSimEG-VRC-CadPack ver 2022

Best,
Sahil

[gavanderhoorn]

You cannot use motoman_driver with MotoSim. Afaik, MotoSim still can't host MotoPlus applications, which is what MotoROS is.

what would you suggest as an alternative to simulate a close to exact scenario before testing on the real robot

exact will not be possible. Not even with MotoSim. All simulations are approximations.

If you're only interested in kinematic playout, converting your MotoSim setup into a URDF and visualising it using RViz may be sufficient.

If you need physics, you could create a Gazebo simulation.

If you don't care about motoman_driver nor physics, you could see whether using the industrial_robot_simulator could be something you could use (you'd still need to model your environment in a URDF though).

[sahilshembekar]

Thank you for the answer.

From the above I can understand that simulation on MotoSim with motoman-ros is not possible as it is not supported.

The method would be to make a URDF of the scenario and using Rviz for visualization and this would be suffice. And for physics, best to use Gazebo.

If you don't care about motoman_driver nor physics, you could see whether using the industrial_robot_simulator could be something you could use (you'd still need to model your environment in a URDF though).

I will checkout the industrial_robot_simulator but, I think I will need to use motoman_driver as I would be using the Motoman ROS interface for moving the robot with code written in ros.
Please correct me if I am wrong.

Also, do you recommend using moveit as an alternative to above? or is the above way more suitable?

Best,
Sahil

[gavanderhoorn]

The method would be to make a URDF of the scenario and using Rviz for visualization and this would be suffice.

Pedantic perhaps, but it could be sufficient.

I'm not aware of (all) your requirements.

And for physics, best to use Gazebo.

Pedantic again, but: Gazebo could be an option. I'm not necessarily recommending it, just providing you a reference to a simulator often used with ROS. There are quite a few more.

If you don't care about motoman_driver nor physics, you could see whether using the industrial_robot_simulator could be something you could use (you'd still need to model your environment in a URDF though).

I will checkout the industrial_robot_simulator but, I think I will need to use motoman_driver as I would be using the Motoman ROS interface for moving the robot with code written in ros. Please correct me if I am wrong.

Unless you have a multi-group system, industrial_robot_simulator offers the same ROS API -- for motion at least -- as motoman_driver.

Also, do you recommend using moveit as an alternative to above? or is the above way more suitable?

I'm not sure I understand.

MoveIt could plan motions for you. It's not an execution environment, nor a simulator.

[EricMarcil]

An alternative would be to use the controller but set it to special playback mode "machine lock" (which will prevent the robot from physically moving but simulate the motion)
Then use MotoSim - Offline option to connect to the controller and display the robot current position (simulated position).

The problem will be that the standard MotoRos driver is retrieving the motor feedback positions and that will not change during simulation. After a brief moment, I believe that ROS will give an error that the robot position is not following the command.
I'm not sure if there is a way to disable that on the ROS side.

On the MotoRos Driver side, there is a hard coded option to switch from reporting the motor feedback to the robot current position (which is updated during simulation) but it would require a recompilation of the driver for which you need the MotoPlus SDK package.
In the Controller.h, uncomment the "#define DUMMY_SERVO_MODE 1" line, recompile the MotoRos driver and then replace the one on the controller. Note that I haven't tested the "DUMMY_SERVO_MODE" recently, so I'm not sure if it is 100% compatible with recent changes. This was used for early development to test different robot configurations for which we didn't necessarily had the physical robot.

This is strickly for testing purpose, running with "DUMMY_SERVO_MODE" version will give less accurate position feedback and is not recommended for normal operation.

[sahilshembekar]

Thank you for the answer.

I will make a note of this method. Let me test and evaluate it once.

Best,
Sahil