This paper presents a study on how the application of scaling techniques to an interface affects its performance. A progressive scaling factor based on the position and velocity of the cursor and the targets improves the efficiency of an interface, thereby reducing the user's workload. The study uses several human-motor models to interpret human intention and thus contribute to defining and adapting the scaling parameters to the execution of the task. Two techniques addressed to vary the control-display ratio are compared, and a new method for aiding in the task of steering is proposed.

A multi-robot cooperation station for nano-bio characterization of biological specimens is presented. The station is composed of two long travel range and high resolution robots equipped with self-sensing nanoprobes that are able to cooperate with each other and with standard AFM systems, over a common sample. The robots are guided by the use of an upright high-depth-of-field optical microscope to perform complex nano-bio characterization experiments. To achieve the required precision between the two robots reference frames, specific image processing techniques are needed. One of the tips is dedicated to acquire the topography of the sample at nano scale while the second probe performs the biocharacterization experiments. The obtained results show that the two robots can cooperate within the required resolution in bacterial nanomechanical characterization while high resolution topographic images are acquired.

In order to enable robots to work in close contact with humans or in environments with unknown obstacles, new reactive control strategies based on sensitive bumper skins are proposed. The aim of this work is to provide a robot with contact and force control based strategies that make it dependable, safe and with foreseeable behaviours. The sensory skin is composed of rigid-bumpers provided with deformation sensors incorporated in a flexible substrate. This solution is a compromise between a simple bumper skin and current array-based robot skins, with better potential performances but, more costly and with usability problems. Such sensitive bumpers cover all moveable links of the robot allowing the detection of collisions, measuring the force involved and locating the point of contact with reasonable precision and cost

An optimal bandwidth allocation policy for axis distributed control using networked control systems (NCS) is presented. First, the benefits of structuring highly articulated robots using networked control systems are discussed. Afterwards, an optimal bandwidth allocation policy for axes distributed control that allows to enhance robot tracking within the available bandwidth is introduced. It will be shown that axes control performance and thus tracking can be significantly improved by using feedback to dynamically allocate bandwidth to axis controllers as a function of the current state of each axis. Simulation results on a multiple axes robot corroborate our approach.

As robotics evolves towards application fields in which humans cooperate with robots, working closer and closer, the requirements for human robot interactions increase. This paper presents new advances in gesture based guidance and control of a robot in assistant tasks. The work described includes the integration of force and vision for the quantitative and qualitative appreciation of human intention and the robot behaviors to respond in real time to these human orders.

Like oral communication, gestures are a natural way to carry out human machine interface. In the early days of robotic systems, human gesture was used to control robot movements by means of a master-slave structure. In spite of the use if robot programming languages, manual control is the most reliable way to carry out complex tasks in unstructured environments. In these situations, a non-contact, passive and remote system can be helpful to control a teleoperated robot by means of human gestures. In this paper, a vision system able to detect, locate and track the head and hands of a human body is presented. The system uses several calibrated cameras placed around the operator scenario to locate the body parts of a person in 3D. The system combines different computer vision techniques to increase the reliability of the body parts detection: image movement detection, user skin colour segmentation and stereo. The data provided by these modules are focused looking for coherence according to the human body dimensions. With the scheme proposed it is possible to obtain a low-cost real-time system for human computer interfacing based in a natural way of communication (gestures). Civil area such as big robots in shipyards, mines, public works or cranes is some possible applications.

The analysis of the error of stereo measurements by triangulation is revisited from three points of view: geometrical, statistical and visual quality. When the target is visible by a set of distributed cameras in the workspace, there are multiple combinations of camera pairs adequate to be considered for the location, by triangulation, of the target position. Three-camera placements are analysed evaluating their precision in a short-medium distance. The work presented analyses which combination of stereo measurements gives the best results, and proposes a method for the automatic selection of the most adequate cameras pair.