Hardware in the loop robot simulators for on-site and remote education in robotics

In this study, a new approach in Hardware-In-the-Loop Simulation (HILS) is introduced as an education tool in robotics, mechatronics and control. The paper discusses the development and utilization of HILS specifically in the instruction of control and design aspects of on-site and remote robotics courses. A HIL simulator differs from computer simulation as it involves actual hardware and is not limited with the software representation of the system. The HIL architecture proposed in this study is a novel contribution to robotics education and is different from previous HIL structures for robotics, in that the developed test-bed involves the actual joint actuator and can be programmed to reflect actual dynamics affecting that particular joint in the given robotic structure. Two motors driven by high performance DSP boards are used for this purpose; one representing the joint actuator and the other used for the generation of all the torque components affecting that joint for the robot system in consideration. Thus, it is possible to evaluate the overall performance of the robot and its end-effector by combining the data from each simulated jointassociated dynamics pair. The wide range of kinematic configurations thus offered by the simple structure of HILS makes them an attractive, cost-effective solution for the problem of limited repertoire in robotics labs, giving the students the opportunity to experiment with 'open architecture robots' that are essential for a thorough education in robot control, but on the other hand are quite rare and may not be available in an average lab environment. Additionally, similar to its use in the robotics lab applications presented in this study, HILS can provide a comprehensive test environment prior to the implementation of new control strategies on the actual system, thereby ensuring the safe use and longevity of high-cost robots in on-site/remote labs. The proposed HIL architecture is combined with a client/server software configuration to allow students access to the test-bed. The results obtained from the remote control of a two-degres-of-freedom planar arm presented as a case study have motivated the utilization of the system as an efficient education and research tool for on-site and remote robotics laboratories.