Quantifying Operational Constraints of Low-Latency Telerobotics for Planetary Surface Operations

NASA's SLS and Orion crew vehicle will launch humans to cislunar space to begin the new era of space exploration. NASA plans to use the Orion crew vehicle to transport humans between Earth and cislunar space where there will be a stationed habitat known as the Deep Space Gateway (DSG). The proximity to the lunar surface allows for direct communication between the DSG and surface assets, which enables low-latency telerobotic exploration. The operational constraints for telerobotics must be fully explored on Earth before being utilized on space exploration missions. We identified two constraints on space exploration using low-latency surface telerobotics and attempts to quantify these constraints. A constraint associated with low-latency surface telerobotics is the bandwidth available between the orbiting command station and the ground assets. The bandwidth available will vary during operation. As a result, it is critical to quantify the operational video conditions required for effective exploration. We designed an experiment to quantify the threshold frame rate required for effective exploration. The experiment simulated geological exploration via low-latency surface telerobotics using a COTS rover in a lunar analog environment. The results from this experiment indicate that humans should operate above a threshold frame rate of 5 frames per second. In a separate, but similar experiment, we introduced a 2.6 second delay in the video system. This delay recreated the latency conditions present when operating rovers on the lunar farside from an Earth-based command station. This time delay was compared to low-latency conditions for teleoperation at the DSG ($\leq$0.4 seconds). The results from this experiment show a 150% increase in exploration time when the latency is increased to 2.6 seconds. This indicates that such a delay significantly complicates real-time exploration strategies.Comment: 10 pages, 8 figures, Proceedings of the IEEE Aerospace Conference, Big Sky, MT. arXiv admin note: text overlap with arXiv:1706.0375

Remote Programming of Multirobot Systems within the UPC-UJI Telelaboratories: System Architecture and Agent-Based Multirobot Control

One of the areas that needs further improvement within E-Learning environments via Internet (A big effort is required in this area if progress is to be made) is allowing students to access and practice real experiments in a real laboratory, instead of using simulations [1]. Real laboratories allow students to acquire methods, skills and experience related to real equipment, in a manner that is very close to the way they are being used in industry. The purpose of the project is the study, development and implementation of an E-Learning environment to allow undergraduate students to practice subjects related to Robotics and Artificial Intelligence. The system, which is now at a preliminary stage, will allow the remote experimentation with real robotic devices (i.e. robots, cameras, etc.). It will enable the student to learn in a collaborative manner (remote participation with other students) where it will be possible to combine the onsite activities (performed “in-situ” within the real lab during the normal practical sessions), with the “on-line” one (performed remotely from home via the Internet). Moreover, the remote experiments within the E-Laboratory to control the real robots can be performed by both, students and even scientist. This project is under development and it is carried out jointly by two Universities (UPC and UJI). In this article we present the system architecture and the way students and researchers have been able to perform a Remote Programming of Multirobot Systems via web

End-to-end congestion control protocols for remote programming of robots, using heterogeneous networks: A comparative analysis

There are many interesting aspects of Internet Telerobotics within the network robotics context, such as variable bandwidth and time-delays. Some of these aspects have been treated in the literature from the control point of view. Moreover, only a little work is related to the way Internet protocols can help to minimize the effect of delay and bandwidth fluctuation on network robotics. In this paper, we present the capabilities of TCP, UDP, TCP Las Vegas, TEAR, and Trinomial protocols, when performing a remote experiment within a network robotics application, the UJI Industrial Telelaboratory. Comparative analysis is presented through simulations within the NS2 platform. Results show how these protocols perform in two significant situations within the network robotics context, using heterogeneous wired networks: (1) an asymmetric network when controlling the system through a ADSL connection, and (2) a symmetric network using the system on Campus. Conclusions show a set of characteristics the authors of this paper consider very important when designing an End-to-End Congestion Control transport protocol for Internet Telerobotics

Control systems with network delay

In this paper motion control systems with delay in measurement and control channels are discussed and a new structure of the observer-predictor is proposed. The feature of the proposed system is enforcement of the convergence in both the estimation and the prediction of the plant output in the presence of the variable, unknown delay in both measurement and in the control channels. The estimation is based on the available data – undelayed control input, the delayed measurement of position or velocity and the nominal parameters of the plant and it does not require apriori knowledge of the delay. The stability and convergence is proven and selection of observer and the controller parameters is discussed. Experimental results are shown to illustrate the theoretical prediction