Arne Bilberg

Design of a flexible tactile sensor for classification of rigid and deformable objects

For both humans and robots, tactile sensing is important for interaction with the environment: it is the core sensing used for exploration and manipulation of objects. In this paper, we present a novel tactile-array sensor based on flexible piezoresistive rubber. We describe the design of the sensor and data acquisition system. We evaluate the sensitivity and robustness of the sensor, and show that it is consistent over time with little relaxation. Furthermore, the sensor has the benefit of being flexible, having a high resolution, it is easy to mount, and simple to manufacture. We demonstrate the use of the sensor in an active object-classification system. A robotic gripper with two sensors mounted on its fingers performs a palpation procedure on a set of objects. By squeezing an object, the robot actively explores the material properties, and the system acquires tactile information corresponding to the resulting pressure. Based on a k nearest neighbor classifier and using dynamic time warping to calculate the distance between different time series, the system is able to successfully classify objects. Our sensor demonstrates similar classification performance to the Weiss Robotics tactile sensor, while having additional benefits.

Classification of rigid and deformable objects using a novel tactile sensor

In this paper, we present a novel tactile-array sensor for use in robotic grippers based on flexible piezoresistive rubber. We start by describing the physical principles of piezoresistive materials, and continue by outlining how to build a flexible tactile-sensor array using conductive thread electrodes. A real-time acquisition system scans the data from the array which is then further processed. We validate the properties of the sensor in an application that classifies a number of household objects while performing a palpation procedure with a robotic gripper. Based on the haptic feedback, we classify various rigid and deformable objects. We represent the array of tactile information as a time series of features and use this as the input for a k-nearest neighbors classifier. Dynamic time warping is used to calculate the distances between different time series. The results from our novel tactile sensor are compared to results obtained from an experimental setup using a Weiss Robotics tactile sensor with similar characteristics. We conclude by exemplifying how the results of the classification can be used in different robotic applications.

Wireless medical sensor measurements of fatigue in patients with multiple sclerosis

This paper presents our experience with developing a portable wireless medical sensor device. We use National Instruments (NI) devices and LabView for measurements studying fatigue of patients suffering multiple sclerosis (MS). Fatigue is a very frequent symptom perceived by MS patients, but the disease mechanism is poorly understood. Many efforts have been made to increase the understanding of this complex phenomenon. It has been found that fatigue might be associated with abnormalities in various anatomical brain areas. Also some secondary factors, not directly related to the disease, such as depression, sleep disorder, severe pain, use of medication and psychological factors might be of importance. However, the relationship with physiological parameters and motion activities in MS patients with fatigue across time are still unknown. Therefore, we hypothesize that we could provide a new assessment of fatigue in MS besides the questionnaires that are currently employed. Furthermore we can discover more secondary factors contributing to fatigue by measuring and monitoring a battery of physiological parameters over an extended time span (e.g. 48 hours) in MS patients without disturbing their normal life behavior. We have developed wireless medical sensor devices and conducted the following, namely Electrocardiograph, body skin temperature, eye movement detection, Electromyograph, motion detection, and muscle strength. In this paper, we describe the technology and design procedures of each measurement and present data from the first two test patients.

Object texture recognition by dynamic tactile sensing using active exploration

For both humans and robots, tactile sensing is important for interaction with the environment: it is the core sensing used for exploration and manipulation of objects. In this paper, we present a method for determining object texture by active exploration with a robotic fingertip equipped with a dynamic tactile transducer based on polyvinylidene fluoride (PVDF) piezoelectric film. Different test surfaces are actively explored and the signal from the sensor is used for feature extraction, which is subsequently used for classification. A comparison between the significance of different extracted features and performance of learning algorithms is done and the best method is further used to classify objects by their surface textures with recognition results higher than 90 percent.

Fatigued patients with multiple sclerosis can be discriminated from healthy controls by the recordings of a newly developed measurement system (FAMOS): a pilot study

Purpose: To explore the difference between fatigued patients with multiple sclerosis (MS) and matched healthy controls by applying a newly developed physiological and functional data recording system. Methods: A portable wireless measurement system, named FAtigue MOnitoring System (FAMOS), has been developed, which can continuously measure electrocardiogram (ECG), body skin temperature, electromyogram, and motion parameters. In a pilot study, 17 fatigued MS patients (fatigue severity scale (FSS) = 53.9 SD 5.4) and 9 healthy matched controls (FSS = 27.2 SD 6.8) were recruited and monitored by FAMOS during the execution of functional (36 m walk test, 5- and 50-repetition sit-to-stand test) and cognitive (short-term memory tests) tests. Furthermore, oxygen saturation (SPO2) was measured during the functional and cognitive tests and during rest periods between these tests. Results: Recordings from FAMOS indicate that fatigued MS patients have reduced standard deviation (SD) of the heart rate (HR) during the short-term memory test, reduced high frequency (HF) component power spectrum (representing parasympathetic activation) at rest after walk test, and higher ratio of low frequency (LF) to HF (LF/HF) during 50-repetition sit-to-stand test. Conclusions: FAMOS recordings can discriminate fatigued MS patients from healthy controls. The data indicate that fatigued MS patients have vagus nerve dysfunction during cognitive tests and disturbed sympathovagal balance during stressful physical tests. Implications for Rehabilitation Fatigue is reported as the most common symptom by patients with multiple sclerosis, but the mechanism of this symptom is still not clearly understood. Wireless body sensor networks is one of the most promising concepts for healthcare and rehabilitation providing long-term health monitoring of subjects under conditions without constraining the subjects’ normal daily activities, but such system has not been used in the study of fatigue in MS. The main findings of this pilot study were that FAMOS can discriminate fatigued MS patients from healthy controls, and recordings extracted from specific monitoring periods indicate autonomic dysfunction in MS patients characterized by primary fatigue.

The Development of an Intelligent Electronic Stethoscope

This paper presents a new concept of home diagnosis system, which is based on an electronic stethoscope and intelligent analyzing software. Heart signal analyzing algorithms as well as the whole developing processes are going to be discussed, which include electronic hardware, embedded system, USB communication, and new designs of the stethoscope. The analyzing software is implemented in LabVIEW, detecting heart sound and separating the signal into two parts automatically: the systolic - the first heart sound (S1) and the diastolic - the second heart sound (S2). The system consequently builds a database of patients including their normal S1 and S2, besides a series of heart disease murmurs are also stored as patterns. The diagnosis algorithm is based on pattern approximation method. Today a pre-industry prototype is available which will be tested by some potential customers and professionals.

A wireless body measurement system to study fatigue in multiple sclerosis

Fatigue is reported as the most common symptom by patients with multiple sclerosis (MS). The physiological and functional parameters related to fatigue in MS patients are currently not well established. A new wearable wireless body measurement system, named Fatigue Monitoring System (FAMOS), was developed to study fatigue in MS. It can continuously measure electrocardiogram, body-skin temperature, electromyogram and motions of feet. The goal of this study is to test the ability of distinguishing fatigued MS patients from healthy subjects by the use of FAMOS. This paper presents the realization of the measurement system including the design of both hardware and dedicated signal processing algorithms. Twenty-six participants including 17 MS patients with fatigue and 9 sex- and age-matched healthy controls were included in the study for continuous 24 h monitoring. The preliminary results show significant differences between fatigued MS patients and healthy controls. In conclusion, the FAMOS enables continuous data acquisition and estimation of multiple physiological and functional parameters. It provides a new, flexible and objective approach to study fatigue in MS, which can distinguish between fatigued MS patients and healthy controls. The usability and reliability of the FAMOS should however be further improved and validated through larger clinical trials.

Novel approaches for bio-inspired mechano-sensors

In this paper, we present novel approaches for building tactile-array sensors for use in robotic grippers inspired from biology. We start by describing the sense of touch for humans and we continue by proposing different methods to build sensors that mimic this behaviour. For the static tactile sense we describe the principles of piezoresistive materials, and continue by outlining how to build a flexible tactile-sensor array using conductive thread electrodes. An alternative sensor is further described, with conductive polymer electrodes instead. For the dynamic tactile sense, we describe the principles of PVDF piezoelectric thin films and how can they be used for sensing. The data acquisition system to process the information from the tactile arrays is covered further. We validate the proposed approaches by a number of applications: classifying a number of fruits and vegetables using only the haptic feedback during their palpation, recognizing objects based on their contact profile and detecting gentle contact and vibrations using the piezoelectric sensor. We conclude by showing what needs to be improved and addressed further to achieve human-like tactile sensing for robots.

Creating and capturing value in a regional innovation ecosystem: a study of how manufacturing SMEs develop collaborative solutions

In this paper, we investigate how a set of small and medium sized enterprises (SMEs) can engage in business model development within a regional innovation ecosystem. We present a case study based on an action research project on how a set of Danish manufacturing SMEs contributed to the development of their local ecosystem in collaboration with a number of external partners. We specifically examine how these SMEs interact with both competitors and complementors in an innovative automation project. The findings include key drivers and challenges that these companies faced while creating and capturing value both for them and the ecosystem at large. We find that the value creation process is enabled by common goals and financial support, while companies need to balance their core activities with their commitment to the joint initiative. Moreover, ecosystem development is centrally dependent on the valuecapture process, which also takes place at the inter-organisational level. Such open innovation process implies a purposive management of knowledge flows at the level of the innovation ecosystem that fits a multi-layered structure of the business model. Through our findings, we link the notions of business model and ecosystems to contribute to the innovation management literature, and to provide practical guidance for future actions within business model and ecosystem development.

Manufacturing Concepts of the Future – Upcoming Technologies Solving Upcoming Challenges

This paper presents an examination of Western European manufacturers‘ future challenges as can be predicted today. Some of the challenges analyzed in the paper are: globalization, individualism and customization and agility challenges. Hereafter, the paper presents a broad analysis on manufacturing concepts and technologies that are being developed today which may be used to solve manufacturing challenges in the future, such as: (self) reconfigurable manufacturing systems, (focused) flexible manufacturing systems, and Al inspired manufacturing. The paper will try to offer a critical point of view on manufacturing hallenges, concepts, and technologies, and is meant to address both academia and industry.