Author: Fausto Vega Email: vegaf1@unlv.nevada.edu
Edited By: Norberto Torres-Reyes Email: torresre@unlv.nevada.edu
Date: Last modified on <04/01/19>
Keywords: Darwin OP , C++/C Programming, Master-Slave

The objective of the tutorial is to implement Master-Slave control between two Darwin OP units. This means that by manually moving the joints of one Darwin OP, one can control the other robot through a common network. Solving this partially or completely is important because it allows for a robust and interactive way to control a robot. This tutorial shows you how to implement this type of control on one arm of the Darwin OP and how to run the program. It takes approximately 30 minutes to complete.

This tutorial's motivation is to teach how to create a Master Slave system between two Darwin OP robots. Readers of this tutorial assumes the reader has the following background and interests:

* Understand C++ Programming basics
* Perhaps also know how to use the Linux command prompt
* Perhaps additional background needed may include Darwin OP basics
* This tutorial may also attract readers who are interested in teleoperation and humanoids

The rest of this tutorial is presented as follows:

• Other Tutorials
• Source Code
• Instructions
• Demonstration
• Final Words

For a background on the Darwin OP basics and a more in depth explanation of network programming refer to the following tutorials:

• Using Darwin-OP
• TCP & UDP Communications

The following folders contain the code used to implement this type of control. It is based off a client server model also know as network programming. In this model, there is a client which connects to the other platform, and the server which makes the request for information from the client. This will allow the two computers inside the Darwin OP’s to communicate over a network. In this case, instead of sending a text message from computer to computer as the original program does, we modified the code to send Dynamixel position values from one platform to the other.

• darwin_client.zip
• darwin_server.zip

This section gives step-by-step instructions along with commands to run the Master-Slave program. Steps 1 and 2 are for users who want to implement on their own robot, DASL users running the demo can skip to Step 3. Designate one robot as the server and one as the client. Both will have their own code.

Download the server folder on one Darwin OP and the client folder on the other Darwin OP

Proceed to the network programming folder through a Linux terminal(ctrl alt t) on each robot with the following command:

Client Robot Statement:

   cd Desktop/darwin_client/Linux/project/network_programming

Then make the code with the following command:

   sudo make

The password for both Darwin's is 111111

Repeat the same process on the server robot.

Server Robot Statement:

   cd Desktop/darwin_server/Linux/project/network_programming

   sudo make

Once the program is built, make sure that both robots are connected to the same network. If running the demo at DASL, both robots must be connected to DASL Warehouse 2.

Run the server program first by accessing the command prompt, then enter the following command (the prompt will ask for the password):

   sudo su
   killall demo

Next, press the reset button on the Darwin OP.
Then, navigate to the network programming folder (as shown above) and running the following command:

   ./server 5000

The 5000 is the port we are using to communicate.

Run the client robot by accessing the command prompt, then enter the following command (the prompt will ask for the password):

   sudo su
   killall demo

Next, press the reset button on the Darwin OP.
Then, navigate to the network folder (as shown above) and running the following command:

   ./client 192.168.50.75 5000

This command specifies the IP address of the server robot and the port number. If this command is not working, check the IP address of the server Darwin with the following command:

   ifconfig

Then insert it for the IP address (192.168.50.75) in the command above.

Once the robot is in walk ready position, the torque on the right arm will turn off after 5 seconds, so make sure to hold the arm. Once the torque is off, move the arm to different positions. One will notice that the same positions will be copied on the robot acting as a server.

To exit out of the program, press control C in the command prompt

In this demonstration, I successfully compiled and execute the program described above

This tutorial's objective was to implement Master-Slave control on two Darwin OP platforms. The source code was provided as well as how to run the program. Once the concepts were conveyed the reader could teleoperate one robot with the joints of another.

Speculating future work derived from this tutorial, includes implementing this control to all the degrees of freedom, and creating an exoskeleton as the Master. In the big picture, the problem of basic Master-Slave teleoperation can be solved with this tutorial.

For questions, clarifications, etc, Email: vegaf1@unlv.nevada.edu

Author: Jean Vaz, Fausto Vega and Yu Hang Email: chagasva@unlv.nevada.edu
Date: Last modified on 04/04/19
Keywords: Teleoperation, Exoskeleton, Human-machine Interface.

Telerobotics Papers

1. The capio active upper body exoskeleton and its application for teleoperation
Publisher: 13th Symposium on Advanced Space Technologies in Robotics and Automation, 2015. Keywords: Humanoids, telerobotics, tele-operation, virtual reality

Mallwitz, M., Will, N., Teiwes, J. and Kirchner, E.A., 2015. The capio active upper body exoskeleton and its application for teleoperation. In Proceedings of the 13th Symposium on Advanced Space Technologies in Robotics and Automation. ESA/Estec Symposium on Advanced Space Technologies in Robotics and Automation (ASTRA-2015). ESA.

This paper describes using a active dual-arm upper body exoskeleton for the teleoperation of an humanoid robot. The authors present a solution for the kinematics and dynamics in real-time for the Capio exoskeleton in order to control the robot AILA. From this presentation, the paper concludes that the Capio exoskeleton was successful integrated into the virtual environment CAVE.

From the state-of-the-art, the paper identifies challenges with haptic devices. The paper addresses these challenges by introducing Capio exoskeleton which is a wearable bakc back with 8 DOF per arm. The results of this approach are novel, showing that a humanoid robot can be used to operate construction machinery, as well as many other devices, giving them flexibility over traditional single-purpose automation.

The paper presents the following theoretical principles: tele-operation parameters & input/output. Little discussion was provided on the humanoid robot principles, however these were provided in some of the cited works.

From the principles and results, the paper concludes that the having the Capio Exoskeleton teleoperating the humanoid robot AILA in ISS mockup is viable, with the following improvements: (1) Improved in manipulation, such as turn switches ; (2) Improved simulations with the simulated lunar mission such as recharging the robots battery at the lander module and submitting the robots status to the ground control; and (3) Improved visual feedback, by having the POV of the robot and the CAD real-time simulation.

I liked this paper because: (1) it presents fundamental work toward utilizing a exoskeleton to manipulate AILA robot; (2) it utilized two types of system integration “CAD model” for the kinematics and “exoskeleton” for toque/force feedback; and (3) it provided comprehensive experimental results for the tele-operation by showing external torques on the Capio exoskeleton transferred from AILA upper arm rotation. However, I lit bit of more explanation on the fundamental kinematics of their CAD mode could have been extremely helpful to the reader.

Three things I learned from this paper were: (1) the basics of design, control and software features for tele-operation; (2) the interaction between the wearable exoskeleton and the physical platform; and (3) safety features implemented in the system to avoid any major damage.

2. An effective and affordable technique for human motion capturing and teleoperation of a humanoid robot using an exoskeleton
Publisher: Humanoids 2017
Keywords: Humanoid Robot, Exoskeleton, Motion Capture, Affordable Teleoperation Technique, Image Processing.

Sinha, A.K., Sahu, S.K., Bijarniya, R.K. and Patra, K., 2017, December. An effective and affordable technique for human motion capturing and teleoperation of a humanoid robot using an exoskeleton. In 2017 2nd International Conference on Man and Machine Interfacing (MAMI) (pp. 1-6). IEEE.

This paper describes using a active dual-arm upper body exoskeleton for the teleoperation of an humanoid robot. The authors present a solution for the kinematics and dynamics in real-time for the Capio exoskeleton in order to control the robot AILA. From this presentation, the paper concludes that the Capio exoskeleton was successful integrated into the virtual environment CAVE.

From the state-of-the-art, the paper identifies challenges with haptic devices. The paper addresses these challenges by introducing Capio exoskeleton which is a wearable bakc back with 8 DOF per arm. The results of this approach are novel, showing that a humanoid robot can be used to operate construction machinery, as well as many other devices, giving them flexibility over traditional single-purpose automation.

The paper presents the following theoretical principles: tele-operation parameters & input/output. Little discussion was provided on the humanoid robot principles, however these were provided in some of the cited works.

From the principles and results, the paper concludes that the having the Capio Exoskeleton teleoperating the humanoid robot AILA in ISS mockup is viable, with the following improvements: (1) Improved in manipulation, such as turn switches ; (2) Improved simulations with the simulated lunar mission such as recharging the robots battery at the lander module and submitting the robots status to the ground control; and (3) Improved visual feedback, by having the POV of the robot and the CAD real-time simulation.

I liked this paper because: (1) it presents fundamental work toward utilizing a exoskeleton to manipulate AILA robot; (2) it utilized two types of system integration “CAD model” for the kinematics and “exoskeleton” for toque/force feedback; and (3) it provided comprehensive experimental results for the tele-operation by showing external torques on the Capio exoskeleton transferred from AILA upper arm rotation. However, I lit bit of more explanation on the fundamental kinematics of their CAD mode could have been extremely helpful to the reader.

Three things I learned from this paper were: (1) the basics of design, control and software features for tele-operation; (2) the interaction between the wearable exoskeleton and the physical platform; and (3) safety features implemented in the system to avoid any major damage.

3. An effective and affordable technique for human motion capturing and teleoperation of a humanoid robot using an exoskeleton
Publisher: Humanoids 2017
Keywords: Humanoid Robot, Exoskeleton, Motion Capture, Affordable Teleoperation Technique, Image Processing.

Sinha, A.K., Sahu, S.K., Bijarniya, R.K. and Patra, K., 2017, December. An effective and affordable technique for human motion capturing and teleoperation of a humanoid robot using an exoskeleton. In 2017 2nd International Conference on Man and Machine Interfacing (MAMI) (pp. 1-6). IEEE.

This paper describes using a active dual-arm upper body exoskeleton for the teleoperation of an humanoid robot. The authors present a solution for the kinematics and dynamics in real-time for the Capio exoskeleton in order to control the robot AILA. From this presentation, the paper concludes that the Capio exoskeleton was successful integrated into the virtual environment CAVE.

From the state-of-the-art, the paper identifies challenges with haptic devices. The paper addresses these challenges by introducing Capio exoskeleton which is a wearable bakc back with 8 DOF per arm. The results of this approach are novel, showing that a humanoid robot can be used to operate construction machinery, as well as many other devices, giving them flexibility over traditional single-purpose automation.

The paper presents the following theoretical principles: tele-operation parameters & input/output. Little discussion was provided on the humanoid robot principles, however these were provided in some of the cited works.

From the principles and results, the paper concludes that the having the Capio Exoskeleton teleoperating the humanoid robot AILA in ISS mockup is viable, with the following improvements: (1) Improved in manipulation, such as turn switches ; (2) Improved simulations with the simulated lunar mission such as recharging the robots battery at the lander module and submitting the robots status to the ground control; and (3) Improved visual feedback, by having the POV of the robot and the CAD real-time simulation.

I liked this paper because: (1) it presents fundamental work toward utilizing a exoskeleton to manipulate AILA robot; (2) it utilized two types of system integration “CAD model” for the kinematics and “exoskeleton” for toque/force feedback; and (3) it provided comprehensive experimental results for the tele-operation by showing external torques on the Capio exoskeleton transferred from AILA upper arm rotation. However, I lit bit of more explanation on the fundamental kinematics of their CAD mode could have been extremely helpful to the reader.

Three things I learned from this paper were: (1) the basics of design, control and software features for tele-operation; (2) the interaction between the wearable exoskeleton and the physical platform; and (3) safety features implemented in the system to avoid any major damage.

4. An effective and affordable technique for human motion capturing and teleoperation of a humanoid robot using an exoskeleton
Publisher: Humanoids 2017
Keywords: Humanoid Robot, Exoskeleton, Motion Capture, Affordable Teleoperation Technique, Image Processing.

Sinha, A.K., Sahu, S.K., Bijarniya, R.K. and Patra, K., 2017, December. An effective and affordable technique for human motion capturing and teleoperation of a humanoid robot using an exoskeleton. In 2017 2nd International Conference on Man and Machine Interfacing (MAMI) (pp. 1-6). IEEE.

This paper describes using a active dual-arm upper body exoskeleton for the teleoperation of an humanoid robot. The authors present a solution for the kinematics and dynamics in real-time for the Capio exoskeleton in order to control the robot AILA. From this presentation, the paper concludes that the Capio exoskeleton was successful integrated into the virtual environment CAVE.

From the state-of-the-art, the paper identifies challenges with haptic devices. The paper addresses these challenges by introducing Capio exoskeleton which is a wearable bakc back with 8 DOF per arm. The results of this approach are novel, showing that a humanoid robot can be used to operate construction machinery, as well as many other devices, giving them flexibility over traditional single-purpose automation.

The paper presents the following theoretical principles: tele-operation parameters & input/output. Little discussion was provided on the humanoid robot principles, however these were provided in some of the cited works.

From the principles and results, the paper concludes that the having the Capio Exoskeleton teleoperating the humanoid robot AILA in ISS mockup is viable, with the following improvements: (1) Improved in manipulation, such as turn switches ; (2) Improved simulations with the simulated lunar mission such as recharging the robots battery at the lander module and submitting the robots status to the ground control; and (3) Improved visual feedback, by having the POV of the robot and the CAD real-time simulation.

I liked this paper because: (1) it presents fundamental work toward utilizing a exoskeleton to manipulate AILA robot; (2) it utilized two types of system integration “CAD model” for the kinematics and “exoskeleton” for toque/force feedback; and (3) it provided comprehensive experimental results for the tele-operation by showing external torques on the Capio exoskeleton transferred from AILA upper arm rotation. However, I lit bit of more explanation on the fundamental kinematics of their CAD mode could have been extremely helpful to the reader.

Three things I learned from this paper were: (1) the basics of design, control and software features for tele-operation; (2) the interaction between the wearable exoskeleton and the physical platform; and (3) safety features implemented in the system to avoid any major damage.

5. An effective and affordable technique for human motion capturing and teleoperation of a humanoid robot using an exoskeleton
Publisher: Humanoids 2017
Keywords: Humanoid Robot, Exoskeleton, Motion Capture, Affordable Teleoperation Technique, Image Processing.

Sinha, A.K., Sahu, S.K., Bijarniya, R.K. and Patra, K., 2017, December. An effective and affordable technique for human motion capturing and teleoperation of a humanoid robot using an exoskeleton. In 2017 2nd International Conference on Man and Machine Interfacing (MAMI) (pp. 1-6). IEEE.

This paper describes using a active dual-arm upper body exoskeleton for the teleoperation of an humanoid robot. The authors present a solution for the kinematics and dynamics in real-time for the Capio exoskeleton in order to control the robot AILA. From this presentation, the paper concludes that the Capio exoskeleton was successful integrated into the virtual environment CAVE.

From the state-of-the-art, the paper identifies challenges with haptic devices. The paper addresses these challenges by introducing Capio exoskeleton which is a wearable bakc back with 8 DOF per arm. The results of this approach are novel, showing that a humanoid robot can be used to operate construction machinery, as well as many other devices, giving them flexibility over traditional single-purpose automation.

The paper presents the following theoretical principles: tele-operation parameters & input/output. Little discussion was provided on the humanoid robot principles, however these were provided in some of the cited works.

From the principles and results, the paper concludes that the having the Capio Exoskeleton teleoperating the humanoid robot AILA in ISS mockup is viable, with the following improvements: (1) Improved in manipulation, such as turn switches ; (2) Improved simulations with the simulated lunar mission such as recharging the robots battery at the lander module and submitting the robots status to the ground control; and (3) Improved visual feedback, by having the POV of the robot and the CAD real-time simulation.

I liked this paper because: (1) it presents fundamental work toward utilizing a exoskeleton to manipulate AILA robot; (2) it utilized two types of system integration “CAD model” for the kinematics and “exoskeleton” for toque/force feedback; and (3) it provided comprehensive experimental results for the tele-operation by showing external torques on the Capio exoskeleton transferred from AILA upper arm rotation. However, I lit bit of more explanation on the fundamental kinematics of their CAD mode could have been extremely helpful to the reader.

Three things I learned from this paper were: (1) the basics of design, control and software features for tele-operation; (2) the interaction between the wearable exoskeleton and the physical platform; and (3) safety features implemented in the system to avoid any major damage.

6. An effective and affordable technique for human motion capturing and teleoperation of a humanoid robot using an exoskeleton
Publisher: Humanoids 2017
Keywords: Humanoid Robot, Exoskeleton, Motion Capture, Affordable Teleoperation Technique, Image Processing.

Sinha, A.K., Sahu, S.K., Bijarniya, R.K. and Patra, K., 2017, December. An effective and affordable technique for human motion capturing and teleoperation of a humanoid robot using an exoskeleton. In 2017 2nd International Conference on Man and Machine Interfacing (MAMI) (pp. 1-6). IEEE.

This paper describes using a active dual-arm upper body exoskeleton for the teleoperation of an humanoid robot. The authors present a solution for the kinematics and dynamics in real-time for the Capio exoskeleton in order to control the robot AILA. From this presentation, the paper concludes that the Capio exoskeleton was successful integrated into the virtual environment CAVE.

From the state-of-the-art, the paper identifies challenges with haptic devices. The paper addresses these challenges by introducing Capio exoskeleton which is a wearable bakc back with 8 DOF per arm. The results of this approach are novel, showing that a humanoid robot can be used to operate construction machinery, as well as many other devices, giving them flexibility over traditional single-purpose automation.

The paper presents the following theoretical principles: tele-operation parameters & input/output. Little discussion was provided on the humanoid robot principles, however these were provided in some of the cited works.

From the principles and results, the paper concludes that the having the Capio Exoskeleton teleoperating the humanoid robot AILA in ISS mockup is viable, with the following improvements: (1) Improved in manipulation, such as turn switches ; (2) Improved simulations with the simulated lunar mission such as recharging the robots battery at the lander module and submitting the robots status to the ground control; and (3) Improved visual feedback, by having the POV of the robot and the CAD real-time simulation.

I liked this paper because: (1) it presents fundamental work toward utilizing a exoskeleton to manipulate AILA robot; (2) it utilized two types of system integration “CAD model” for the kinematics and “exoskeleton” for toque/force feedback; and (3) it provided comprehensive experimental results for the tele-operation by showing external torques on the Capio exoskeleton transferred from AILA upper arm rotation. However, I lit bit of more explanation on the fundamental kinematics of their CAD mode could have been extremely helpful to the reader.

Three things I learned from this paper were: (1) the basics of design, control and software features for tele-operation; (2) the interaction between the wearable exoskeleton and the physical platform; and (3) safety features implemented in the system to avoid any major damage.

7. Intention-Based EMG Control for Powered Exoskeletons
Publisher: IEEE Transactions on Biomedical Engineering 2012
Keywords: Biomedical Engineering, Exoskeleton, EMG, human-assistive robotics

T. Lenzi, S. M. M. De Rossi, N. Vitiello and M. C. Carrozza, “Intention-Based EMG Control for Powered Exoskeletons,” in IEEE Transactions on Biomedical Engineering, vol. 59, no. 8, pp. 2180-2190, Aug. 2012.

This paper describes using Electromyographical (EMG) signals to control an elbow powered exoskeleton. The authors presents the description of the simple EMG-based proportional control system and its implementation on the NEUROExos platform, a powered exoskeleton for elbow assistance. The authors presents the results of ten healthy subjects' participation in experimentations where this technology was used to produce simple periodic elbow movement. From this presentation, the paper concludes that, even with a simple proportional EMG control, subjects adapt almost instantaneously to the assistance provided by the robot and can reduce their muscular effort while maintaining control of the movement.

From the state-of-the-art, the paper identifies challenges in using EMG signals to estimate human muscular torques and apply this information effectively on human-assistive robotics. The technique is highly limited by the necessity of complex user-dependent and session-dependent calibration procedures. The paper addresses these challenges by proposing a simple proportional EMG control where users can calibrate the proportional gains independently in short amount of time. The results of this approach are that subjects can quickly adapt to the proportional EMG control based elbow exoskeleton and use the skeleton to control their arm movement in sync with designed visual and audio feed-back.

The paper presents the following theoretical principles: (1) The central nervous system's ability to adapt to external motor disturbances can allow subjects to compensate for the inaccuracy of EMG-signal-based torque estimation;(2) A simple proportional EMG control system applied on exoskeleton can allow subjects to benefit from assistive power from robot without needs for high precision muscular torque measurement; and (3) a simple calibration process where the subject adjust the gain value directly while testing the system.

The principles are explained fairly. For example the experimentation method show the correct application of the principles.

From the principles and results, the paper concludes: (1) a proportional EMG control applied to exoskeleton is sufficient to provide movement assistance; (2) subjects were able to maintain control of movement and accuracy of movement in both amplitude and frequency; and (n) subjects were able to adapt to the assistance provided by exoskeleton in short periods of time (a few seconds).

I liked this paper because the authors were able to arrange experimentation that provided positive experimental results that support their hypothesis. I disliked this paper because the author made assertive conclusion based on a narrow experimentation arrangement. The experiment only focused on one degree-of-freedom elbow movement. Furthermore, visual and audio feedback on the accuracy of movement could have contributed to the success. I would have liked to see the authors apply the same control system on multiple-degree-of-freedom exoskeleton and limit the effect of visual and audio feedback.

Three things I learned from this paper were: (1) the limitation of EMG signal in estimate muscular torque; (2) the limitation of extensive session and individual-dependent calibration process for assistive technology; and (3) central nervous system's ability to adapt can overcome the inaccuracy in technology.