OBJECTIVE: To develop a conceptual framework for the design of an in-home monitoring system (IMS) based on the requirements of older adults with vision impairment (VI), informal caregivers and eye-care rehabilitation professionals. MATERIALS AND METHODS: Concept mapping, a mixed-methods statistical research tool, was used in the construction of the framework. Overall, 40 participants brainstormed or sorted and rated 83 statements concerning an IMS for older adults with VI. Multidimensional scaling and hierarchical cluster analysis were employed to construct the framework. A questionnaire yielded further insights into the views of a wider sample of older adults with VI (n=78) and caregivers (n=25) regarding IMS. RESULTS: Concept mapping revealed a nine-cluster model of IMS-related aspects including affordability, awareness of system capabilities, simplicity of installation, operation and maintenance, system integrity and reliability, fall detection and safe movement, user customization, user preferences regarding information delivery, and safety alerts for patients and caregivers. From the questionnaire, independence, safety and fall detection were the most commonly reported reasons for older adults and caregivers to accept an IMS. Concerns included cost, privacy, security of the information obtained through monitoring, system accuracy, and ease of use. DISCUSSION: Older adults with VI, caregivers and professionals are receptive to in-home monitoring, mainly for fall detection and safety monitoring, but have concerns that must be addressed when developing an IMS. CONCLUSION: Our study provides a novel conceptual framework for the design of an IMS that will be maximally acceptable and beneficial to our ageing and vision-impaired population.

The pattern of airflow has a significant influence on the ability of both animals and robots to detect and locate sources of volatile chemicals. This paper describes a project to build a robot chemical sensing system based on observations of airflow around the human body. These observations indicate that in low-velocity airflow air warmed by body heat rises and carries odorants from near ground level towards the nose. This implies that under the right conditions large areas of the human body act to collect and direct odour chemicals to the nose. The aim of this project is to investigate the feasibility of this odour collection mechanism by building a robotic odour sensing system working on this principle and to compare it with the same chemical sensor system when not heated. The results indicate the improved sensitivity of the heated sensor system. This paper describes the sensor system and gives results of sensor tests and odour source location experiments performed using it.

This paper investigates an algorithm, which improves the task completion rate for simple swarm robots implementing a leaf-curling task. In this biologically inspired task, robots collaborate to find a suitable place to bend a leaf, which allows them to successfully fold it up. To complete the task simple robots were developed that are not equipped with any direct communication devices. They communicate via sematectonic stigmergy, which means every robot can only gain information via changes in their working environment, which are made by other robots. This type of communication has proved beneficial in helping swarm robots monitor the performance of other swarm members without direct contact, team mate localization or recognition. However, in earlier experiments, implementing the leaf-curling task, information perceived by every robot has not been effectively used to create meaningful collaboration. This disadvantage becomes evident via the low task completion rate. If robots explore their environment, this will improve the outcome by increasing the probability of finding the most suitable part of the leaf to work on. In this paper, an algorithm enabling swarm robots to effectively explore the environment and find the most effective place to perform the leaf-curling task is described in detail. The improvement of completion rate, achieved by this exploring rule, is verified by both simulation and physical experiments with a group of W-AntBots.

This paper describes an ongoing project to investigate the possibility of using pheromone communication in a robot swarm. The project is inspired by the queen bee pheromone. A queen bee releases pheromones throughout a colony to coordinate the actions of its members. The pheromones have a number of crucial functions in a bee colony, such as keeping together and stabilizing the colony. In the context of a robot swarm, one of the proposed applications for robot pheromones is to allow swarm members to be guided by a robot leader. The robot leader releases different chemicals to elicit different behaviors. In this project, temperature modulation of tin oxide gas sensors have been implemented in order to differentiate different chemicals. This paper provides details of the swarm robots used in the project and their behaviors. The sensors, especially temperature modulation of the tin oxide gas sensors, and the robot control algorithms are described. Results of practical experiments and simulations are also presented

Odour localisation in an enclosed area is difficult due to the formation of sectors of circulating airflow. Well-defined plumes do not exist, and reactive plume following may not be possible. Odour localisation has been partially achieved in this environment by using knowledge of airflow, and a search that relies on chemical sensing and reasoning. However the results are not specific, with the odour source only restricted to a broad area. This paper presents a solution to the problem by introducing a second search stage using visual sensing. It therefore comprises a bi-modal, two-stage search, with each stage exploiting complementary sensing modalities. This paper presents details of the method and experimental results

This paper introduces a method of building topological maps using sequences of images and the approximate string matching algorithm, which is commonly used in DNA sequence alignment applications. Contrary to many existing dense image based topological localisation techniques that operate in known maps, our method builds topological maps in unknown environments. And unlike traditional topological mapping methods that require the robot to explicitly recognise topological path junctions during exploration, our method requires no such explicit "junction detectors". It receives as input only a sequence of unlabeled images. The validity of the approach has been demonstrated in both indoor and outdoor environments. The largest outdoor map created measures 70 by 40 meters with 3 nested loops. The system has shown robustness towards large amounts of sensor aliasing and noise caused by errors in the path following behaviours

The robot mole project at Monash University aims to develop robotic systems for locating the source of volatile chemicals released underground. As part of this project, a mobile robot, MOLE I has been designed that takes readings of underground chemical concentrations by inserting a probe into the ground at a sequence of locations. The robot is guided towards regions of higher chemical concentration using the hex-path algorithm. This algorithm was developed especially for the task of locating underground chemical sources and this is the first time that it has been tested using a mobile robot. There are important economic, environmental and humanitarian applications for systems that can find the source of an odor or volatile chemical located beneath the ground. These applications range from harvesting truffles, to finding the location of leaking chemical storage tanks and unexploded ordinance. In this paper, the robot construction and hex-path algorithm are described together with experimental results that demonstrate the capabilities of the robot system.

The behaviour that allows mobile robots to follow what humans consider as paths is beneficial for autonomous navigation in a wide range of environments. Paths can be corridors, footpaths, catwalks, roads, etc. In fact roads can be considered as well-structured paths. Traditional approaches to path following has been extensions of road following systems. We present a vision-based path following method different to that of the traditional model fitting approach of road following. The method focuses on tracking the direction in which parallel lines in the environment are aligned. It is similar in principle to methods that extract vanishing points but with better robustness achieved with appropriate simplifying assumptions. Some preliminary results of successful path following experiments are also presented.

This paper describes current progress in a project to develop a robot for locating underground chemical sources. There are important economic, environmental and humanitarian applications for systems that can find the source of an odor or volatile chemical located beneath the ground. These applications cover the spectrum from harvesting truffles, to finding the location of leaking gas pipes and land mines. In previous work the feasibility of detecting vapor percolating through the ground was demonstrated. An algorithm was then developed to control a robot enabling it to gather information about the location of the source and to guide the robot towards it. This algorithm was limited to searching in two dimensions (depth was held constant). In this paper the original algorithm is extended to 3-dimensions allowing variations in depth to be included. The 3-dimensional search algorithm involves following a path through the ground that corresponds to the edges of closely packed dodecahedra. Simulations and physical experiments both confirm the capabilities of this search algorithm.

In this paper, a distributed mechanism used by a robotic swarm to facilitate the building of a loose wall structure is discussed and results presented. The ability of a robotic swarm to utilise a spatio-temporal varying template in construction tasks is verified. The work is seen as a step towards the development of a generalised methodology for collective construction building tasks and establishes a means for the building of more complex structures.

This paper describes the development of complementary chemical and airflow sensing systems for a humanoid robot. In recent years there has been growing interest in the development of humanoid robots. To function in a safe and efficient manner a humanoid robot must be 'aware' of its surroundings. For both a human and a humanoid robot two important and inter-related stimuli are odor and airflow. An electronic nose allows odors to be detected and discriminated. Measurement of airflow in the vicinity of a humanoid robot provides important information for localising the source of an odor. In this way, sensors for odor and airflow complement each other. Airflow sensors also measure local air movement and can detect such things as draughts resulting from open doors and the air disturbance caused by walking close to the humanoid robot. This paper describes progress in the development of both the electronic nose and airflow measuring system for a humanoid robot.

In order to operate effectively in their variable and unstructured real world environment insects employ many strategies. Generating and detecting odours is the basis of several of these strategies. It seems certain that similar techniques can be implemented to improve the competence of robotic systems. This paper describes a project to investigate transferring the pheromone trail tracking capabilities of ants to robotic systems. A robotic ant has been built and equipped with a pair of odour sensing 'antennae'. This system has been programmed with a trail following algorithm observed in the ant Lasius fuliginosus. The design of this robot, the control algorithm and results of odour trail following experiments are presented.

Robots for nonindustrial tasks must function in less organised and predictable environments than industrial ones. This paper describes a technique for assisting mobile robots to navigate in the home and outlines progress towards a practical system. The technique involves laying and detecting trails on the ground. Of particular interest are trails which disperse after use and therefore do not require removal and do not interfere with trails laid later. These techniques are termed short-lived navigational markers (SLNM). Trails of heat are considered. Proposed applications include marking of areas already painted, searched etc., retracing a path to the starting point, and following another robot (making a train). A simple mobile robot has been designed as a test bed for heat trail laying and detection experiments. It is small and inexpensive and therefore suited to experiments involving a number of interacting robots. Heat sensors and applicators are described, together with results.

Shape memory alloy (SMA) based actuators have a number of attributes which make them useful for robotic applications. Unfortunately their response is relatively slow being limited by the speed with which the SMA can be heated and cooled. This paper describes two novel developments of the basic SMA actuator which improve dynamic performance. To allow rapid heating of the shape memory alloy wire without the danger of over heating an infrared temperature sensor is introduced. Cooling is improved with the aid of a mobile heat sink. These developments are described and preliminary results are presented.

Tracing leaks of airborne radioactive, poisonous or flammable materials is a potentially dangerous activity that could be undertaken by robotic systems. This paper describes a practical investigation of the possibility of developing simple, low cost, autonomous robots to perform this task. It is envisaged that these robots would be used in large numbers. This would improve reliability through redundancy and provide large area coverage from a wide distribution of robots. Failure of a single unit would not jeopardise the overall sensing operation. Sensing and control techniques developed to perform leak location in a simplified laboratory environment are described and experimental results are presented.

By monitoring or following trails layed on the ground a mobile robot can perform several useful navigation tasks. An example would be following a trail layed on an outward journey in order to later find the way back to the starting point. This paper describes the latest stage in the development of a robot navigation system based on laying down and detecting trails of volatile chemicals. Previously a prototype olfactory sensor was developed which showed the feasibility of having a mobile robot follow an odour trail on the floor. This prototype sensor has now been improved by managing airflow in the vicinity of the sensor. This has decreased the sensor response time and improved rejection of spurious odour signals carried by airflow in the room. A simple and effective applicator has also been developed for laying odour trails.>

Introduces the concept of short-lived navigational markers (SLNMs) which represent a group of techniques for indicating the path taken by a mobile robot. Information provided by marking the robot trajectory can be of direct assistance in a number of navigation tasks. The short-lived nature of the markers has the advantage that it is not necessary to remove them after use. However, the varying intensity of the SLNMs complicates the process of detecting and following the robot path. Heat is one form of SLNM being investigated and this paper describes a pyroelectric sensor which has been developed to detect thermal paths created by heating the floor with a quartz halogen bulb. Three control strategies for following the thermal trail have been developed and tested. A strategy based on Kalman filtering gives the best performance. Details of the control strategies are presented together with experimental results showing how they performed in practice.

The author describes the first stage in the development of a robotic manipulator system for assembly, disassembly and adjustment of micro-mechanical devices. Mobility is provided by a six-degree-of-freedom parallel actuated manipulator using spring-tensioned tendons. A miniature gripper is actuated by shape memory alloy and incorporates an optical sensor to measure finger separation. The prototype system was constructed using readily available components and materials. The manipulator system can perform a minimum movements of less than 0.05 mm and grasp objects in the size range 0.2 mm to 2 mm. However, a lot of scope remains for improving the accuracy and resolution of the manipulator and reducing the size of the gripper.

The author describes the first stage of a project to gather three-dimensional information about the world using whisker sensors. Design criteria for the whisker sensors were accuracy, speed, and durability. Preliminary work has shown that detailed surface profiles can be recorded by scanning passive whisker sensors over a surface using a robot arm to provide mobility. Results which demonstrate that whisker sensors can determine the profile of both concave and convex surfaces are presented. However, there were situations in which the whisker sensor fails to provide correct information. Additional sensors have been incorporated into the whiskers to detect these conditions so that the false information can be discarded. An array of whiskers has been simulated by repeated scanning with a single whisker sensor. Further work which aims to increase the scanning speed of the sensor by creating an array of a whiskers and by improving the data collection facilities is outlined.>

A new design of robot tactile sensor is described which features a highly compliant structure. Sensor compliance accommodates a degree of inaccuracy in robot positioning, aids stable grasping and resists damage. Silicone rubber sheet forms the outer skin of the sensor which is supported by a core of polyurethane foam. Contact with external objects causes bending and stretch in the silicone rubber skin and this is detected by conductive rubber strain gage elements attached to the inner surface of the skin. The sensor construction is described and results obtained using prototype versions of the sensor are presented.