Robot-based System Research Articles

Towards a Smooth Human–Robot Interaction for Rehabilitation Robotic Systems

The goal of this work is to develop a control framework to provide assistance to the subjects in such a manner that the interaction between the subjects and a robot-assisted rehabilitation system is smooth during the rehabilitation therapy. In order to achieve smoothness of interaction, a control framework is designed in such a way that it can automatically adjust the control gains of the robot-assisted rehabilitation system to modify the interaction dynamics between the system and the subject. An artificial neural network (ANN)-based proportional–integral (PI) gain scheduling controller is proposed to automatically determine the appropriate control gains for each individual subject. The human arm model is integrated with the ANN-based PI gain scheduling controller where the ANN uses estimated human arm parameters to select the appropriate PI gains for each subject such that the resultant interaction dynamics between the subject and the robot-assisted rehabilitation system could result in smooth interaction. Experimental results involving unimpaired subjects on a PUMA robot-based rehabilitation system are presented to demonstrate the efficacy of the proposed ANN-based PI gain scheduling controller on unimpaired subjects.

Investigation of laser remote welding using disc laser

Laser remote welding techniques are used to enhance the flexibility of laser welding process and remote welding systems based on solid-state lasers and robots are of special interest to the automotive. There are two concepts available to implement laser remote welding—the scanner-integrated system and the robot-based system. The scanner-integrated system utilizes a 2- or 3-axis optical unit for bead deflection and focusing and the robot-based system employs a long focal length laser optic and a 6-axis robot. As thin disk lasers and fiber lasers with good focusability have been recently developed, the remote welding system becomes more practicable. In this study, the robot-based remote welding was implemented and the welding characteristics were investigated. Working areas and process windows are also a matter of great concern to the field application, which was evaluated by experimental approach.

Robot-Based Tele-Echography

The TER system is a robot-based tele-echography system allowing remote ultrasound examination. The specialist moves a mock-up of the ultrasound probe at the master site, and the robot reproduces the movements of the real probe, which sends back ultrasound images and force feedback. This tool could be used to perform ultrasound examinations in small health care centers or from isolated sites. The objective of this study was to prove, under real conditions, the feasibility and reliability of the TER system in detecting abdominal aortic and iliac aneurysms. Fifty-eight patients were included in 2 centers in Brest and Grenoble, France. The remote examination was compared with the reference standard, the bedside examination, for aorta and iliac artery diameter measurement, detection and description of aneurysms, detection of atheromatosis, the duration of the examination, and acceptability. All aneurysms (8) were detected by both techniques as intramural thrombosis and extension to the iliac arteries. The interobserver correlation coefficient was 0.982 (P < .0001) for aortic diameters. The rate of concordance between 2 operators in evaluating atheromatosis was 84% +/- 11% (95% confidence interval). Our study on 58 patients suggests that the TER system could be a reliable, acceptable, and effective robot-based system for performing remote abdominal aortic ultrasound examinations. Research is continuing to improve the equipment for general abdominal use.

A six-legged robot-based system for humanitarian demining missions

Removal of antipersonnel landmines is a worldwide problem currently requiring the use of new technologies such as improved sensors and efficient mobile robots. This paper is focused on the description of a system that relies on a walking robot that carries sensors to detect and locate antipersonnel landmines efficiently and effectively. The paper describes the main features of the walking robot and additional equipment purposefully developed for this kind of application. The overall system consists of a sensor head that can detect certain landmine types, a manipulator to move the sensor head over large areas, a locating system based on a global positioning system, a remote supervisor computer and the SILO6 walking robot used as the subsystems’ carrier. The whole system has been configured to work in a semi-autonomous mode with a view also to robot mobility and energy efficiency. Some of the achievements already accomplished with this system are reported.

Precise robot-assisted guide positioning for distal locking of intramedullary nails

This paper presents a novel image-guided robot-based system to assist orthopedic surgeons in performing distal locking of long bone intramedullary nails. The system consists of a bone-mounted miniature robot fitted with a drill guide that provides rigid mechanical guidance for hand-held drilling of the distal screws' pilot holes. The robot is automatically positioned so that the drill guide and nail distal locking axes coincide, using a single fluoroscopic X-ray image. Since the robot is rigidly attached to the intramedullary nail or bone, no leg immobilization or real-time tracking is required. We describe the system and protocol and present a method for accurate and robust drill guide and nail hole localization and registration. The in vitro system accuracy experiments for fronto-parallel viewing show a mean angular error of 1.3 degrees (std = 0.4 degrees ) between the computed drill guide axes and the actual locking holes axes, and a mean 3.0 mm error (std = 1.1 mm) in the entry and exit drill point, which is adequate for successfully locking the nail.

Optimised robot-based system for the exploration of elastic joint properties

Numerous publications provide measured biomechanical data relating to synovial joints. However, in general, they do not reflect the non-linear elastic joint properties in detail or do not consider all degrees of freedom (DOF), or the quantity of data is sparse. To perform more comprehensive, extended measurements of elastic joint properties, an optimised robot-based approach was developed. The basis was an industrial, high-precision robot that was capable of applying loads to the joint and measuring the joint displacement in 6 DOF. The system was equipped with novel, custom-made control hardware. In contrast to the commonly used sampling rates that are below 100 Hz, a rate of 4 kHz was realised for each DOF. This made it possible to implement advanced, highly dynamic, quasi-continuous closed-loop controllers. Thus oscillations of the robot were avoided, and measurements were speeded up. The stiffness of the entire system was greater than 44 kNm(-1) and 22 Nm deg(-1), and the maximum difference between two successive measurements was less than 0.5 deg. A sophisticated CT-based referencing routine facilitated the matching of kinematic data with the individual anatomy of the tested joint. The detailed detection of the elastic varus-valgus properties of a human knee joint is described, and the need for high spatial resolution is demonstrated.

A robot-assisted system for long bone intramedullary distal locking: concept and preliminary results

This paper presents a new robot-based system to assist orthopaedic surgeons in performing distal intramedullary locking in femoral and tibial fracture reduction. The system consists of a miniature bone-mounted robot fitted with a drill guide that provides mechanical guidance for manual drilling of the distal screws' pilot holes. The drill guide and the nail's distal locking holes axes are automatically aligned with a few X-ray fluoroscopic images. The goal is to eliminate the guesswork from drill positioning, thus reducing surgery time and surgeon's cumulative radiation exposure, and to ensure drill and hole's axis alignment during drilling, thus eliminating geometric errors and their complications. We describe the system's rationale and concept, its architecture and usage protocol, the image processing and registration algorithms, and preliminary experimental results.

Robot-based gauging system

Robot-based gauging system

Cost and performance analysis of a robotic rework cell

Printed circuit board assembly (PCBA) rework is an acceptable process step in PCBA manufacturing and widely performed using manual and semi-automated tools. Until recently, there has been a lack of international effort for the development of a fully automated rework system mostly due to the predicted high capital cost of such system. Since robots are used in PCBA manufacturing, PCBA robots are equipped and have been developed with multi-functional capabilities to assemble and inspect PCBAs. If the same equipment is used for rework, the high cost of the robot, on account of vision and other sensory needs can be eliminated and this can justify the investment. A robot-based rework system thus becomes an alternative technology to manual or semi-automated rework. Because there is no information on which technology is most appropriate, a model has been developed to predict the cost of reworking PCBAs using semi-automated and automated-robotic rework technologies. These two alternative rework technologies are analysed and compared to give an indication of how appropriate is a robotic rework cell.

Automated E-field scanning system for dosimetric assessments

The interest in accurate dosimetric measurements inside phantoms that simulate biological bodies has burgeoned since several regulatory commissions began calling for or recommending the testing for compliance with safety standards of low power devices. This paper presents a newly developed, robot-based system that allows automated E-field scanning in tissue simulating solutions. The distinguishing characteristics of the system are its high sensitivity and its broad dynamic range (1 /spl mu/W/g to 100 mW/g) over the entire frequency range (10 MHz to over 3 GHz) used for mobile communications. The reproducibility of the dosimetric evaluations has been shown to be considerably better than /spl plusmn/5%. This has been accomplished by the use of an improved isotropic E-field probe connected to amplifiers with extremely low noise and drift characteristics in conjunction with digital processing of the data. Special emphasis has been placed on system reliability, user-friendliness and graphic visualization of data.

Robot integration within computer-integrated manufacture

Increasingly robots form part of a complex automation scheme, dictating a requirement for robot control systems which can communicate beyond their local working environment. This paper explains how MAP Version 2·1 broadband local area network interfaces have been used to facilitate robot integration with computer-integrated manufacturing systems and describes integration methodologies which can find widespread application. To illustrate the principles involved a robot-based flexible assembly system has been constructed to assemble and test printed circuit boards. Each machine element of the flexible assembly system has been linked to a MAP backbone through the use of ‘OSI intelligent interfaces’ (or gateways). The interfaces incorporate INI COMMengines and were constructed at Loughborough University to achieve MAP to machine-specific protocol conversion and where appropriate to provide enhanced front-end processing facilities in the locality of machines. The paper also describes the features and use of an...

Robot-based system used in reactor vessel inspection

Robot-based system used in reactor vessel inspection

Hierarchical Control of a Robot-Based Adjustment and Testing System

Hierarchical Control of a Robot-Based Adjustment and Testing System

Simulation of human judgement in a robot-based adjustment system

SUMMARYA robot-based automatic system for adjusting energy regulators in electric cookers is described in this paper. It is claimed that this system improves the quality of the regulators and increases productivity. First, the operator's intuitive judgement and decision-making are simulated on a microcomputer; the structure and performance variables of the regulator are then described. A discussion of computer modelling of the regulator then follows, leading to the development of an algorithm for the adjustment procedure and overall strategy of the system. Experiments on 2,000 regulators showed that this automated operation was superior to the manual procedure as regards consistency and accuracy. This technique based on a robot may be applied to quality control and manufacture of a variety of similar products.