In this paper we present the networked robotics approach to dynamic architecture creation. Building on our prior work we highlight the ease at which system and architecture creation can be moved from the single robot domain to the cooperative/multiple robotic domain; indeed under the networked robotic framework there are no differences between the two, as a multiple, cooperative, robotic architecture simply emerges from a richer network environment (the module pool). Essentially task-driven architectures are instantiated on an as needed basis, allowing conceptualised designs to be run wherever a suitable framework (i.e. a module pool) exists. In this paper we demonstrate this framework applied in the creation of a multi robot system, highlighting the flexibility and robustness of the approach, and the experimental freedom inherent within it. The approach has been tested experimentally.

Exploration of high risk terrain areas such as cliff faces and site construction operations by autonomous robotic systems on Mars requires a control architecture that is able to autonomously adapt to uncertainties in knowledge of the environment. We report on the development of a software/hardware framework for cooperating multiple robots performing such tightly coordinated tasks. This work builds on our earlier research into autonomous planetary rovers and robot arms. Here, we seek to closely coordinate the mobility and manipulation of multiple robots to perform examples of a cliff traverse for science data acquisition, and site construction operations including grasping, hoisting, and transport of extended objects such as large array sensors over natural, unpredictable terrain. In support of this work we have developed an enabling distributed control architecture called control architecture for multirobot planetary outposts (CAMPOUT) wherein integrated multirobot mobility and control mechanisms are derived as group compositions and coordination of more basic behaviors under a task-level multiagent planner. CAMPOUT includes the necessary group behaviors and communication mechanisms for coordinated/cooperative control of heterogeneous robotic platforms. In this paper, we describe CAMPOUT, and its application to ongoing physical experiments with multirobot systems at the Jet Propulsion Laboratory in Pasadena, CA, for exploration of cliff faces and deployment of extended payloads.

The visual acts theory aims to provide intelligent assistance for camera viewpoint selection during teleoperation. It combines a top-down model to partition a task into a sequence of operations and a bottom up component that monitors the operator in order to select task-relevant camera viewpoints in a timely manner for the operator. In a previous paper the authors (2001) presented results showing that visual acts does indeed provide a camera view of sufficient quality to allow an operator to complete a task. In this paper we present further results that bear on the performance of visual acts. The results provide further insights into the provision of operator controls for teleoperation and the role of additional cues, such as shadows, in task completion.

This paper describes recent work undertaken at the Jet Propulsion Laboratory in Pasadena, CA in the area of increased rover autonomy for planetary surface operations. The primary vehicle for this work is the Field Integrated, Design and Operations (FIDO) rover. The FIDO rover is an advanced technology prototype that is a terrestrial analog of the Mars Exploration Rovers (MER) being sent to Mars in 2003. We address the autonomy issue through improved integration of rover based sensing and higher level onboard planning capabilities. The sensors. include an inertial navigation unit (INU) with 3D gyros and accelerometers, a sun sensor, mast and body mounted imagery, and wheel encoders. Multisensor fusion using an Extended Kalman Filter (EKF) approach coupled with pattern recognition and tracking algorithms has enabled the autonomy that is necessary for maximizing science data return while minimizing the number of ground loop interactions. These algorithms are coupled with a long range navigation algorithm called ROAMAN (Road Map Navigation) for an integrated approach to rover autonomy. We also report the results of algorithm validation studies in remote field trials at Black Rock Summit in Central Nevada, California's Mojave Desert, and the Arroyo Seco at JPL.

We have developed a cliff robot that is capable of descending a cliff and autonomously navigating to way-points on the cliff wall. This aggressive mobility system consists of an ensemble of three tethered robots, which cooperate under tight coordinated control and collective state estimation. The distributed task is described as a behavior network, which consists of a network of controllers spread across the robots and which interact through communication links to achieve a collective control objective. Fielded experimental results show that the cliff robot is capable of navigating to designated way-points on a cliff wall using the proposed control scheme.

The objective of the Robot Work Crew (RWC) project is to investigate key challenges in multi-robot coordination when performing tightly coupled coordination tasks such as transporting and handling of long objects on challenging planetary terrain. In this paper, we focus on tightly coupled coordination of two Mars rovers transporting a long payload. We have developed practical decentralized compliancy control and coordinated comply control algorithms that effectively address compliant control for compliantly coupled multiple mobile robots. Experiments at the Jet Propulsion Lab in Pasadena, CA of two Mars rovers carry an extended payload over uneven, natural terrain are used to validate and illustrate the approach.

In this paper we present research aimed at exploring the configuration of robot architecture from robot components that are distributed about a network environment. The research is motivated by previous work focusing on representation and reasoning methods for modeling modular robotics systems. We look specifically at self-configuring networked robotic agents. The proposed model combines the notions of a task factory that generate task modules and a pool of modules representing robotics components such as sensors and effectors. A number of successively more complex scenarios are used to illustrate the concepts. These have been implemented and tested experimentally. The paper describes the experimental implementation.

This paper describes the Visual Acts theory and architecture for automated camera placement during teleoperation. The theory is motivated by the goal to provide operators with task relevant information in a timely manner. The Visual Acts architecture combines top-down deliberative task modelling with bottom-up reactive observation of an operator to select camera views which provide the operator with task-relevant information. The paper describes the reactive component of the architecture, its implementation in an agent-based architecture and experimental results that confirm the validity of the approach.

The paper describes a new sun sensor for absolute heading detection developed for the Field Integrated, Design and Operations (FIDO) rover. The FIDO rover is an advanced technology rover that is a terrestrial prototype of the rovers NASA/Jet Propulsion Laboratory (JPL) plans to send to Mars in 2003. Our goal was to develop a sun sensor that fills the current cost/performance gap, uses the power of subpixel interpolation, makes use of current hardware on the rover, and demands very little computational overhead. The need for a sun sensor on planetary rovers lies in the fact that current means of estimating the heading of planetary rovers involves integration of noisy rotational-speed measurements. This noise causes error to accumulate and grow rapidly. Moreover, the heading error affects the estimate of the x and y position of the rover. More importantly, incremental odometry heading estimation is only reliable over relatively short distances. There is an urgent need to develop a new heading-detection sensor for long traverses [for example, 100 m per Sol (Martian Day)], as requested for future Mars mission. Results of a recent FIDO field trial at Black Rock Summit in Central Nevada and several operations readiness tests at the JPL MarsYard using the sun sensor have demonstrated threefold to fourfold improvement in the heading estimation of the rover compared to incremental odometry.

This paper describes the use of an image-plane robot control method known as camera space manipulation for remote planetary surface operations using a three degree-of-freedom arm mounted on a lander base. Because of incompatibilities that may exist in the image-plane target objectives that are required for the camera space manipulation method the final positioning precision of the arm relative to a point in 3D space is investigated. The experimental system developed required only minimal modifications to the existing Martian lander facility and the system achieved positioning precision on the order of 5 mm or less. Autonomous operation of the system was successfully demonstrated for task such as autonomous sample acquisition.

In this paper we present research which is exploring the use of perceptual models in the construction of automated viewing systems for operator viewing during teleoperation. We show how a perceptual discrimination model can be used for selecting a set of viewing directions for one phase of the peg-in-hole task and hence a pattern of looking, or "visual act". We introduce "visibility modelling" as a way of mapping from the task environment to the discrimination model.

By automating viewing during teleoperation the operator can be released from the need to manually set camera viewing parameters, which distracts from the central component of the task, robotic manipulation. The challenge of automation is to manage the duality of automatic-control versus operator-in-control. Specifically, the operator needs to 'feel' in control, since otherwise confidence in the system, and hence performance, will be poor. We propose an approach that combines deliberative task models, models of human perception and reactive architectures. We use the peg-in-hole task as a case study and discuss the mapping of viewing requirements onto the camera resources defining the remote viewing facilities.

The teleprogramming system is a supervisory control approach to time delayed teleoperation that incorporates predictive graphics and reactive skills to accomplish dexterous manipulation tasks in the presence of significant time delay. This paper presents an experimental effort to validate the teleprogramming system using the GRASP Laboratory of the University of Pennsylvania as the operator station and the TROPICS Laboratory of the Jet Propulsion Laboratory as the remote site. The teleprogramming experiment involved operator supervisory control of a robot performing puncture and slice operations on the thermal blanket securing tape of a satellite repair mission sub-task This experiment was successfully performed in August, 1994 using the Internet as the sole medium of communication. During experimentation, messages experienced time-varying time delay between three and fifteen seconds with an average delay of approximately six seconds.

This paper briefly describes an advanced teleoperator (ATOP) system and its control station where a variety of computer-based operator interface devices and techniques are integrated into a functional setting, accommodating a primary operator and secondary operators. Computer graphics is a key operator interface component in the control station where new types of manual interface devices also are employed. The results of some generic and application task experiments are summarized, including the performance of a simulated remote satellite servicing task, carried out under four to eight seconds communication time delay, using satellite TV and Internet computer communication links. In conclusion, the paper highlights the lessons learned so far.>

Recent advances in real-time 3-D computer graphics and hierarchically structured graphical user interfaces (GUI) enable development of very efficient graphics-based operator interfaces for telerobotic operations. This paper addresses potential benefits of such advanced graphics interfaces to telerobotic servicing and inspection, emphasizing operator efficiency and system safety. Specifically, the authors report on calibrated 3-D graphics displays and GUIs developed and applied to an advanced teleoperation system and a remote surface inspection system at the Jet Propulsion Laboratory.

In this paper, we focus on the role and im- portance of experiments in the development of tele- operation systems. Experiments conducted in the JPL Advanced Teleoperation Laboratory and les- sons we have learned from them are described. We also describe novel procedures and techniques that facilitate the conduct of experiments and these are presented in this paper. Also reported are problems faced in a laboratory that develops new teleoperation technology while concurrently validating the tech- nology with experiments.

This paper provides a capsular introduction to the theoretical framework and experimental applications of the Polar Exponential Grid (PEG) transformation, in the context of image analysis. The PEG transformation is an isomorphic (1) representation of the image intensity array that simplifies, and potentially offers new insights about, a variety of tasks in computational vision. We describe the PEG transform representation; we briefly survey its functional precursors in optical computing and image processing. We then give an example of PEG-based image analysis for rotation-and-scale variant template matching and, present the PEG transform as a motif for a class of problems in stochastic estimation of object boundaries.