Robotic Kinematic and Dynamic Simulations
Craig Carignan


Neutral buoyancy provides a high fidelity simulation for developing and training. However, there are times when one of the underwater vehicles is either not functioning or not available. The use of a computer simulation fills the void allowing for some level of training and development without the actual vehicle. Even with a relatively low-fidelity computer simulation, much can be accomplished with the system.

The same input devices, control station, and graphical simulation are used during the computer simulations as TSX and NBV robotic operations. The figure below shows how each of the software processes are linked together. The Arm Control Simulation is a functional equivalent of the control software used on the actual robot to command its manipulators. The Arm Interaction Simulation is a mathematical process that runs on a computer to mimic the behavior of the actual robot. This includes addition of manipulator dynamics, collision with the worksite, and manipulating maintenance task elements. Data from the arm simulations are streamed to update the status on the control station panels. The graphical simulation is used in place of live video coming back from the robot.

The training simulations have been used to assist new operators to learn the fundamentals of controlling the robot. Lessons are learned on how to properly use the different input devices, how each of the control station functions are utilized, and what the procedure steps are for performing specific tasks. Using these simulations, novices with no prior experience controlling robots, including young children, have learned enough to pilot neutral buoyancy vehicles within a few minutes.Another project, SCAMP, which is designed to fly within the tank and take video. Every year an open house event allows the general public to control a telerobot. People from all ages and backgrounds learn how to use the ground control station to adequately fly the training simulation. After only a few minutes of experimentation with the simulation, they more confidently take controls of the actual underwater vehicle.

Although the training simulations have proved successful in quickly reducing the learning times of operators, the greater advantage these simulations have provided is the capability to develop the robotic system. Over five hundred hours of human factors testing has occurred using the simulations to determine the best strategies for controlling Ranger remotely under different amounts of time delay. The arm control software has been tested extensively using many hours of computer simulations, debugging code, adjusting control parameters, and developing unique control methods before testing with hardware. And much analysis has used the graphical simulations to test ideas out before considering major design steps. Before changing the size and length of manipulators, the computer simulations were updated and used to determine if such a design change was required.

 Related Works:

Carignan Craig R., David L. Akin and J. Corde Lane. "Dynamic Tool Vectors forRobo-Centric Control". IEEE International Conference on Robotics and Automation. 2000.

Carignan, Craig R., J. Corde Lane, and David L. Akin. "Real-Time Simulation Of A Free-Flying Robotic Vehicle". AIAA Modeling and Simulation Technologies Conference. 1999.