42391520
Are You Being Served?
There has been a lot of talk about service robots over the past decade, and indeed some service robots are starting to make their way into the real world; delivering food in hospitals, turning book pages for people with physical diabilities, and the like. Unfortunately, while functional, these robots perform their jobs with all the panache of machines. When people want service robots they really want “servant robots” but without the social guilt that now often accompanies the hiring of actual human servants. To do servants correctly, it is necessary to have a hierarchy in the ‘help’. Only the Dark Knight has been able to maintain style and social standing with a single servant The AAAI-97 Conference Reception is the AI community’s social event of the season. Here, as with almost all AI activities, style and social standing are everything. AI researchers work hard, and when they party, they want to be pampered. Procuring one’s own food is gauche; the AI community wants to be served. Towards this end, KIPR is creating a pair of servant robots (Capt. Peacock and Mr. Humphries) to serve and cater to their charges every gastromical need, while maintaining that old-world flavor that lets you know that while your servants may be smarter, stronger and more expensive than you, they are definitely your social inferiors.
303726
Simplified navigation and traverse planning for a long-range planetary rover
This paper presents the sensor and control system for SR2, a planetary rover prototype capable of km+/day traverses through Mars-like terrain. The control system described allowed the rover to successfully navigate Mars-like terrain given a set of way-points spaced approximately 100 m apart. The control system uses input from a variety of sensors including heading, roll, pitch, an array of proximity sensors, voltage and current sensors, and a depth from stereo camera system. The control system is adequate, when combined with the rover's mobility system to make its way over or around almost all hazards a rover is likely to encounter, and to know when it is getting diverted so far off course that it needs to ask for help. In a recent field test, the robot autonomously navigated through 1.3 km of Mars like terrain to reach its goal. The SR2 is a solar powered, four-wheeled rover that masses 21 kg and fits inside a 90/spl times/65/spl times/40 cm envelope.
43128338
Experiences with an architecture for intelligent, reactive agents
This paper describes an implementation of the 3T robot architecture which has been under development for the last eight years. The architecture uses three levels of abstraction and description languages which are compatible between levels. The makeup of the architecture helps to coordinate planful activities with real-time behaviours for dealing with dynamic environments. In recent years, other architectures have been created with similar attributes but two features distinguish the 3T architecture: (1) a variety of useful software tools have been created to help implement this architecture on multiple real robots; and (2) this architecture, or parts of it, have been implemented on a variety of very different robot systems using different processors, operating systems, effectors and sensor suites.
2634305
Deadlines, Travel Time, and Robot Problem Solving
1 Abstract This paper describes some extensions to the reductionist planning paradigm typified by Sacerdoti's NOAH program. Certain inadequacies of the partial ordering scheme used in NOAH are pointed out and a new architecture is detailed which circumvents these problems. An example from the semi-automated factory domain is used to illustrate features of the new planner. Techniques for eliminating unnecessary travel time by the robot and avoiding backtracking due to deadline failures are discussed and their incorporation in the planner is described. 2 Introduction Most planners since NOAH [8] have represented a plan for a set of tasks as a partial (ie., non-linear) ordering of the steps required for carrying out those tasks. NOAH and its successors (eg., NONLIN [9] and DEVISER [10]) employ a partially ordered network of tasks to avoid early and unnecessary commitment to task orderings. The motivation for this is to eliminate backtrack-ing. However, maintaining a consistent partial order is difficult in domains where the fact that tasks actually take time plays an important role: domains in which deadlines or robot travel time are serious considerations. That a partial order leads unavoidably to a deadline failure usually cannot be discovered until an attempt is made to linearize the ordering. However, failure to notice a deadline violation early will require backtracking later. In addition, planning with a partial order is not well suited to efficiently managing factors like travel or machine running time. It's not difficult to represent that moving from one workstation to another takes time proportional to the distance separating the two workstations. However, generating a plan that eliminates unnecessary travel between workstations requires exploring some of the linearized task orderings. It is not until tasks are completely ordered that the source and destination workstations of each movement can be known and the travel time computed with any accuracy. In this paper we describe an approach to planning that combines the use of a partial order with a method for exploring the possible repercussions of that partial order. This approach has been implemented in the FORBIN planner (First Order RoBot INtender). FORBIN is a planner capable of solving a significantly wider class of problems than any of its predecessors. 2.1 The Factory Domain One problem domain that has been used for exploring our approach to planning is what we refer to as the semi-automated factory. In this domain a mobile robot operator wanders about the …
18083854
Attitude and Position Control Using Real-Time Color Tracking
A variety of sensors and positioning methods have been developed over the years. Most methods rely on active sensors (such as sonars or lasers) which have range and power restrictions, or rely on computationally complex (and often slow) methods such as recovering position from stereo or optical flow. This paper describes a system that can determine a robot's position and orientation, in all six degrees of freedom, relative to a simple passive target. The system can determine its position relative to the target from a single image frame, and process the image and calculate the position faster than a camera's frame rate (60Hz). It uses a standard, uncalibrated color video camera as its sensor. The system runs on an inexpensive microprocessor (a Motorola 68332) leaving many cycles left over. By careful design of the target and the vision processing hardware and software, we are able to selectively perceive only the relevant parts of the target, greatly simplifying and speeding all the necessary computations. The system is being developed for autonomous spacecraft station keeping and docking.
21145709
A Hybrid Genetic Algorithm for the Single Machine Scheduling Problem
A hybrid genetic algorithm (HGA) is proposed for the single machine, single stage, scheduling problem in a sequence dependent setup time environment within a fixed planning horizon (SSSDP). It incorporates the elitist ranking method, genetic operators, and a hill-climbing technique in each searching area. To improve the performance and efficiency, hill climbing is performed by uniting the Wagner-Whitin Algorithm with the problem-specific knowledge. The objective of the HGA is to minimize the sum of setup cost, inventory cost, and backlog cost. The HGA is able to obtain a superior solution, if it is not optimal, in a reasonable time. The computational results of this algorithm on real life SSSDP problems are promising. In our test cases, the HGA performed up to 50% better than the Just-In-Time heuristics and 30% better than the complete batching heuristics.
1636963
On the Specification of Sequent Systems
Recently, linear Logic has been used to specify sequent calculus proof systems in such a way that the proof search in linear logic can yield proof search in the specified logic. Furthermore, the meta-theory of linear logic can be used to draw conclusions about the specified sequent calculus. For example, derivability of one proof system from another can be decided by a simple procedure that is implemented via bounded logic programming-style search. Also, simple and decidable conditions on the linear logic presentation of inference rules, called homogeneous and coherence, can be used to infer that the initial rules can be restricted to atoms and that cuts can be eliminated. In the present paper we introduce Llinda, a logical framework based on linear logic augmented with inference rules for definition (fixed points) and induction. In this way, the above properties can be proved entirely inside the framework. To further illustrate the power of Llinda, we extend the definition of coherence and provide a new, semi-automated proof of cut-elimination for Girard’s Logic of Unicity (LU).
17886110
Using a single address space operating system for distributed computing and high performance
Recent 64-bit microprocessors have made a huge 18.4 quintillion byte address space potentially available to programs. This has led to the design of Operating Systems that provide a single virtual address space in which all code and data reside in and that spans all levels of storage and all nodes of a distributed system. These operating systems called SASOSs, have characteristics that can be used to support synchronization and coherency in a distributed system in ways that provide an improved program development environment and higher performance than that available from conventional operating systems. Sombrero, our SASOS design, makes use of its hardware support for object-grained protection, separate thread related protection domains and implicit protection domain crossing to provide synchronization and coherency support for distributed object copy set management not available in SASOSs built on stock processors. Its design, which provides direct system level support for object oriented programming includes a number of system architectural features targeted at modern distributed computing.
15440056
Unification Under a Mixed Prefix
Abstract Unification problems are identified with conjunctions of equations between simply typed λ-terms where free variables in the equations can be universally or existentially quantified. Tow schemes for simplifying quantifier alternation, called Skolemization and raising (a dual of Skolemization), are presented. In this setting where variables of functional type can be quantified and not all types contain closed terms, the naive generalization of first-order Skolemization has several technical problems that are addressed. The method of searching for pre-unifiers described by Huet is easily extended to the mixed prefix setting, although solving flexible-flexible unification problems is undecidable since types may be empty. Unification problems may have numerous incomparable unifiers. Occasionally, unifiers share common factors and general of these are presented. Various optimizations on the general unification search problem are as discussed.
839746
Roadmap for enhanced languages and methods to aid verification
This roadmap describes ways that researchers in four areas---specification languages, program generation, correctness by construction, and programming languages---might help further the goal of verified software. It also describes what advances the "verified software" grand challenge might anticipate or demand from work in these areas. That is, the roadmap is intended to help foster collaboration between the grand challenge and these research areas.A common goal for research in these areas is to establish language designs and tool architectures that would allow multiple annotations and tools to be used on a single program. In the long term, researchers could try to unify these annotations and integrate such tools.