Amit Goradia

Design and Analysis of Internet-Based Tele-Coordinated Multi-Robot Systems

The coordination of multi-robots is required in many scenarios for efficiency and task completion. Combined with teleoperation capabilities, coordinating robots provide a powerful tool. Add to this the Internet and now it is possible for multi-experts at multi-remote sites to control multi-robots in a coordinated fashion. For this to be feasible there are several hurdles to be crossed including Internet type delays, uncertainties in the environment and uncertainties in the object manipulated. In addition, there is a need to measure and control the quality of tele-coordination. To this end, the measure of force sensed by each robot is suggested and justified as a coordination index. It was proven that if n robots are event-transparent and event-synchronous then they can be teleoperated under random delay conditions to coordinate to any index value, which is feasible under no delay conditions. The design procedure that ensures a system can satisfy a small coordination index was presented and analyzed.In addition, the design and analysis of event-synchronous systems using Petri Nets is detailed. The Petri Net design methodology is presented for both event-synchronous single operator single robot teleoperation systems and event-synchronous multi-operator multi-robot teleoperation systems.The theory developed was tested by bilaterally tele-coordinating two mobile manipulators via the Internet. The experimental results confirmed the theoretical results presented.

Internet based robots: applications, impacts, challenges and future directions

The Internet has ushered in the era of an exceedingly connected digital lifestyle. It has brought about a lot of changes in the social arena and has revolutionized the way we communicate with each other. Internet based teleoperation systems utilize the ubiquitous connectivity and low cost bandwidth offered by the Internet to send commands and receive supermedia feedback for teleoperating remote systems. Teleoperation systems have many myriad applications and impact areas ranging from education and entertainment to remote exploration and medicine. Such wide ranging applications of Internet based teleoperation systems have many social implications and a profound impact on the day-to-day human lifestyle. This paper tries to elaborate on the many application areas of Internet based teleoperation and further discusses the social implications of the same. Further, the paper discusses various technical challenges and research issues related to Internet based teleoperation systems and provides a few experimental results on some teleoperation systems implemented at the Robotics and Automation Laboratory at Michigan State University and the Communication and Robotics Laboratory at Oakland University.

Modeling and design of mobile surveillance networks using a mutational analysis approach

Networked surveillance systems provide an extended perception and distributed reasoning capability in monitored environments through the use of multiple networked sensors. The challenge for such large scale networked systems is to design an efficient modeling and analysis tool and devise stable control algorithms for accomplishing the surveillance task. Current feature (point) based visual servo and tracking techniques generally employed do not provide an optimal solution for the surveillance task. This paper presents a mutational analysis approach for shapes, and shape based control to model and design mechanisms for such active surveillance systems. The techniques of image based Hausdorff tracking and cooperative Hausdorff tracking are introduced. Finally, experimental results demonstrate the efficacy of the proposed approach for tracking targets over a large area.

Tele-coordinated control of multi-robot systems via the Internet

The coordination of multi-robots is required in many scenarios for efficiency and task completion. Combined with teleoperation capabilities, coordinating robots provide a powerful tool. Add to this the Internet and now it is possible for multi-experts at multi-remote sites to control multi-robots in a coordinated fashion. For this to be feasible there are several hurdles to be crossed including Internet type delays, uncertainties in the environment and uncertainties in the object manipulated. In addition, there is a need to measure and control the quality of tele-coordination. This paper proposes a measure for the quality of tele-coordination, referred to as the coordination index, and details the design procedure that ensures a system performs at a required index. The theory developed was tested by bilaterally tele-coordinating two mobile manipulators via the Internet. The experimental results confirmed the theory presented.

Coordination of human and mobile manipulator formation in a perceptive reference fame

This paper presents an analysis and design method for human/robot integrated systems, especially fro the coordination of human and robot formations based on a group of distributed mobile manipulators. The key for the human/robot integrated system is to create a common motion reference that can be understood by both human and the robots in the formation. First, the perceptive reference frame is introduced and the characteristics of perceptive frame are compared with time based reference frame. Next, the stability of the system based on perceptive reference frame is investigated. The applications of perceptive reference frame to multi-agents coordination in a formation, human/mobile manipulators coordination are then discussed. Based on the perceptive reference frame, the human can be naturally integrated into the robot formation. Human intelligence can therefore be integrated with the mobility and dexterous manipulation capability of the mobile manipulators to undertake complex tasks. The robot formation is therefore able to reconfigure and thus cope with unexpected events. Experiments have been used to verify the theoretical results.

QoS management of supermedia enhanced teleoperation via overlay networks

In supermedia enhanced Internet based teleoperation systems, the data flowing between the operator and the robot include robotic control commands, video, audio, haptic feedback and other media types. The difference between an Internet based teleoperation system and other Internet applications are that (1) there are many media types involved in teleoperation systems and each of them has a particular quality of service (QoS) requirement; and (2) some media types are very latency sensitive. Overlay networks have been proposed to improve the QoS of teleoperation applications. However efficient use the overlay network resources and the distribution of these resources optimally to all supermedia streams remains an important problem. This paper aims to provide a framework of QoS management for teleoperation systems over overlay networks. The validity and performance of the system is evaluated using the PlanetLab overlay network.

Pervasive surveillance using a cooperative mobile sensor network

A distributed processing and communication approach is applied to networked surveillance systems providing an extended perception and sensing capability in monitored environments. By pervasive we mean that the entire surveyed area is covered by a heterogeneous collection of fixed and mobile sensors. The sensor network uses a cooperative tracking technique that allows for the deployment of mobile sensors based on data provided by other sensors in the network. Also, an image-based tracking technique is used for tracking when the target is in view. The task of tracking multiple targets in a distributed surveillance network is a challenging problem because of the following reasons: (1) multiple targets need to be monitored and tracked continuously and must remain in view of at least one of the sensors; (2) the view of the sensors needs to be optimized so that the targets are observed with a discernible resolution for feature identification; (3) it is important to devise stable control algorithms for accomplishing the surveillance task; (4) assigning tracking tasks to sensors must consider load balancing and efficient use of all sensors. This paper presents a distributed communication and processing model that allows for a fast deployment of sensor nodes and implementation of ad hoc tracking in a multi-target surveillance scenario. Also, experimental results demonstrate the efficacy of the proposed approach for tracking multiple targets over a large area with fixed and mobile sensors

Improving the Operation Efficiency of Supermedia Enhanced Internet Based Teleoperation via an Overlay Network

For Internet based real-time teleoperation systems, random time delay can cause instability in the closed loop control system and hence hinder task accomplishment. Event based control systems have been proposed to overcome the instability caused by the random time delay. High latency at the transport layer can still impede effective and reliable execution of tasks with high dexterity requirements. Network QoS based dynamic resource allocation has been proposed to increase the efficiency and reliability of task execution. However, these approaches only try to mitigate or overcome the effects of random time delay and do not address the cause of latency issues in the communication channel. This paper addresses the efficiency and reliability requirements for supermedia enhanced teleoperated systems by reducing the end-to-end transmission latency through the use of overlay networks. The proposed system reduces the transmission latency by using multiple, disjoint paths in overlay networks. The proposed system facilitates reliable and efficient task completion for tasks with high dexterity requirements. Experimental validation of the proposed teleoperated system using the PlanetLab Network is provided for the task of teleoperating a mobile manipulator system.

Cooperative multi-target surveillance using a mutational analysis approach

Networked surveillance systems provide an extended perception and distributed sensing capability in monitored environments through the use of multiple networked sensors. The task of tracking multiple targets in a surveillance network is a challenging problem because of the following reasons: (1) multiple targets need to be monitored and tracked continuously so that they would not leave the view of at least one of the sensors; (2) the view of the sensors needs to be optimized so that at a given time the targets are observed with a discernable resolution for feature identification; (3) it is important to devise stable control algorithms for accomplishing the surveillance task. Current feature (point) based visual surveillance and tracking techniques generally employed do not provide an adequate framework to express a surveillance task. This paper presents a mutational analysis approach for shape based control to model a multi-target surveillance scenario. It further presents an optimal multiple sensor task planning algorithm based on the target resolution and priority, to achieve optimal coverage of multiple targets in the sensing region of the surveillance network. Finally, experimental results demonstrate the efficacy of the proposed approach for tracking multiple targets over a large area

Dynamic multi-objective optimal task distribution for tele-operated mobile manipulators

Robots are developed to perform myriad kinds of complex tasks. To enhance the system performance, tasks should be optimally distributed among robots or subsystems of a single robot. Applied to mobile manipulators, optimal task distribution can be obtained by implementing an optimal redundancy resolution approach. A lot of work has been done in this area with a priori-specified tasks. However, for tele-operated mobile manipulator systems, tasks are generated on-line by the operator, and task requirements vary significantly and are not known a priori. This renders static task distribution schemes unsuitable for achieving optimal performance and mandates the use of online modification of optimal task distribution algorithms. This paper proposes a new optimal task distribution method for tele-operated mobile manipulators. In this method, task dexterity indices, which describe the task requirements are generated online. Based on these indices, the criterion function for optimal performance is constructed using physical programming. The solution obtained by this algorithm is more suitable for varying tasks, and has a better defined physical meaning. The effectiveness of the proposed method is verified by experimental results.