Miguel Angel Sánchez Urán - Academia.edu (original) (raw)

Papers by Miguel Angel Sánchez Urán

Advances in Intelligent Systems and Computing, 2019

This paper presents ExoFlex, an upper-limb flexible exoskeleton (exosuit) intended for assistance... more This paper presents ExoFlex, an upper-limb flexible exoskeleton (exosuit) intended for assistance in elbow and shoulder rehabilitation therapies. The soft nature of the device allows it to easily adapt to human biomechanics. The presented exosuit is equipped with a cable-driven transmission in which torque is generated by two direct current (DC) motors. A super-twisting sliding mode controller (SMC) has been simulated and implemented for elbow and shoulder flexion and extension movements. ExoFlex has proven to effectively assist its wearer in experimental tests.

2021 IEEE 2nd International Conference on Human-Machine Systems (ICHMS), 2021

Flexible exoskeletons are lightweight robots that surround the user’s anatomy to assist or oppose... more Flexible exoskeletons are lightweight robots that surround the user’s anatomy to assist or oppose motion. Their structure is made of light and flexible materials, like fabrics, so the forces created by the robot are directly transferred to the user’s musculoskeletal system. Exosuits are thus sensitive to the sliding of the actuation, textile perturbations and improper fitting to the user. LUXBIT is a cable-driven flexible exoskeleton that combines fabrics and sewing patterns to promote its anatomical adaption. The exoskeleton is intended for bimanual assistance of daily tasks and long-term usage. To this end, the system reduces the pressures applied to the user and the misalignment of the actuation by stacking textile patches. The patches enhance the functioning of the base garment and promote the transference of the assistance forces. Additionally, LUXBIT has a compact actuation with deformable components to prevent the user movements from being restricted. The exoskeleton is portable by using an enhanced textile backpack. This paper shows the exoskeleton’s benefits for trajectory and muscle activity during the flexion of the shoulder and the elbow.

Lecture Notes in Computer Science

2008 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2008

This work is focused on obtaining efficient human hand models that are suitable for manipulation ... more This work is focused on obtaining efficient human hand models that are suitable for manipulation tasks. A 24 DoF kinematic model of the human hand is defined to realistic movements. This model is based on the human skeleton. Dynamic and Static constraints have been included in order to improve the movement realism. Two simplified hand models with 9 and 6 DoF have been developed according to the constraints predefined. These simplified models involve some errors in reconstructing the hand posture. These errors are calculated with respect to the 24 DoF model and evaluated according to the hand gestures. Finally, some criteria are defined to select the hand description best suited to the features of the manipulation task.

IEEE Transactions on Instrumentation and Measurement, 2011

This paper describes data processing using a haptic interface for virtual object grasping tasks. ... more This paper describes data processing using a haptic interface for virtual object grasping tasks. The haptic interface known as MasterFinger-2 (MF-2) is used. This haptic device enables the simulation of object manipulation using the thumb and index finger, which are inserted within thimbles located at the far end of the haptic interface. The experiments were conducted using a setup that provides the operator with two MF-2s. This setup enables bimanual virtual object manipulation. The haptic device provides data about the angular position of all joints and data from four contact sensors located within the thimbles. The values obtained from the angular positions of the joints enable a calculation of the position and orientation of the thimbles, whereas the values obtained from the contact sensors are used to formulate an approximate calculation of the user's force during object manipulation. This information regarding forces enables the segmentation of manipulation tasks and is essentially based on the rising edges produced by the contact sensor signals. After performing task segmentation, the state of the task in progress is detected. This facilitates improvements in user interaction because restrictions can be established in the relationships between the objects that change dynamically depending on the stage of manipulation. This information allows for an improvement in the realism of the simulation because the forces reflected take into account how the relationships between objects vary over the course of the task. Task segmentation is also used to ascertain objects' physical properties. These features are then used to simulate virtual objects with the same properties.

IEEE Robotics & Automation Magazine, 2008

Human visual mechanisms are well described in the literature [7], [8]. Howard and Rogers give an ... more Human visual mechanisms are well described in the literature [7], [8]. Howard and Rogers give an excellent review of the main

This paper describes dynamic constraints of a human hand model. Inter-finger and intra-finger con... more This paper describes dynamic constraints of a human hand model. Inter-finger and intra-finger constraints have been develop in order to obtain quite realistic manipulation. Keywords--human hand model, inter-finger, intrafinger, constraints.

This study presents the development of a wearable device that merges capacitive soft-flexion and ... more This study presents the development of a wearable device that merges capacitive soft-flexion and surface electromyography (sEMG) sensors for the estimation of shoulder orientation and movement, evaluating five natural movement gestures of the human arm. The use of Time Series Networks (TSN) to estimate the arm orientation, and a pattern recognition method for the estimation of the classification of the gesture are proposed. It is demonstrated that it is possible to know the orientation of the shoulder, and that the algorithm is capable of recognising the five gestures proposed with two different configurations. The study is performed on people who reported healthy upper limbs.

Journal of Physics: Conference Series

Flexible exoskeletons, also known as exosuits, are robotic wearable devices intended to help heal... more Flexible exoskeletons, also known as exosuits, are robotic wearable devices intended to help healthy and unhealthy subjects in different tasks, such as daily life activities, load lifting or rehabilitation. A position control is required to assure stability and compliance in all assisted movements. In this paper, the authors propose the use of a flexible position sensor based on differential capacitance measurement as position feedback for the elbow joint in the flexible exoskeleton LUXBIT. This exosuit is controlled in position by a super-twisting sliding mode controller (SMC), which is robust against disturbances. Different movements involved in rehabilitation therapies are performed over three healthy subjects in order to evaluate the exosuit performance using this motion sensor. The measures given by the flexible sensor are compared to the ones obtained by OptiTrack motion capture system, which are used as ground truth.

Sensors

Recovery of therapeutic or functional ambulatory capacity in patients with rotator cuff injury is... more Recovery of therapeutic or functional ambulatory capacity in patients with rotator cuff injury is a primary goal of rehabilitation. Wearable powered exoskeletons allow patients to perform repetitive practice with large movements to maximize recovery, even immediately after the acute event. The aim of this paper is to describe the usability, acceptability and acceptance of a hybrid exoskeleton for upper-limb passive rehabilitation using the System Usability Scale (SUS) questionnaire. This equipment, called ExoFlex, is defined as a hybrid exoskeleton since it is made up of rigid and soft components. The exoskeleton mechanical description is presented along with its control system and the way motion is structured in rehabilitation sessions. Seven patients (six women and one man) have participated in the evaluation of this equipment, which are in the range of 50 to 79 years old. Preliminary evidence of the acceptance and usability by both patients and clinicians are very promising, obta...

2020 IEEE International Conference on Human-Machine Systems (ICHMS)

Exoskeletons are human-machine interaction devices that can either assist or oppose the user’s mo... more Exoskeletons are human-machine interaction devices that can either assist or oppose the user’s motion. Soft exoskeletons are lightweight devices whose lack of rigid pieces provides them with soft behaviour. These exosuits use textiles and soft actuation mechanisms to enhance compliance and comfort during user interaction. The absence of a rigid structure, thereby, provokes drawbacks related to force transfer and fixation of the system to the wearer’s anatomy. Commonly-reported issues include textile-slippery phenomena, pressure-related discomfort, actuation perturbations due to muscle volume variability and joint misalignment during human motion. This paper introduces the fixation solution adopted in LuxBit, a textile-wearable cable-driven exoskeleton to assist elbow and shoulder flexion. Different textiles and sewing patterns are combined in this coupling-interface to promote force distribution and adaption to the wearer’s anatomy. Then, the document assesses the assistance capability of the device by measuring the trajectory and electromyography signals of four subjects while flexing the elbow and shoulder up to 90 degrees. The experiments also allow discussing the benefits for a healthy user in both cases, when carrying a 0.75kg load and not.

This paper presents the monitoring architecture and experience gained in a pilot distribution gri... more This paper presents the monitoring architecture and experience gained in a pilot distribution grid designed for continuous control of insulation condition of the grid by means of PD measurements. Powerful data processing tools are used for the discrimination of PD pulses from background noise, for locating different PD sources, for clustering PD sources and for identification of the defect associated to each PD source.

Sensors, 2015

Partial discharge (PD) measurements provide valuable information for assessing the condition of h... more Partial discharge (PD) measurements provide valuable information for assessing the condition of high voltage (HV) insulation systems, contributing to their quality assurance. Different PD measuring techniques have been developed in the last years specially designed to perform on-line measurements. Non-conventional PD methods operating in high frequency bands are usually used when this type of tests are carried out. In PD measurements the signal acquisition, the subsequent signal processing and the capability to obtain an accurate diagnosis are conditioned by the selection of a suitable detection technique and by the implementation of effective signal processing tools. This paper proposes an optimized electromagnetic detection method based on the combined use of wideband PD sensors for measurements performed in the HF and UHF frequency ranges, together with the implementation of powerful processing tools. The effectiveness of the measuring techniques proposed is demonstrated through an example, where several PD sources are measured simultaneously in a HV installation consisting of a cable system connected by a plug-in terminal to a gas insulated substation (GIS) compartment.

ABSTRACT Resumen Este artículo describe los trabajos realizados hasta la fecha en el desarrollo d... more ABSTRACT Resumen Este artículo describe los trabajos realizados hasta la fecha en el desarrollo del robot modular RobMAT. Se describe el módulo propuesto que equilibra complejidad con prestaciones; es decir la dificultad de diseño e integración de los elementos que forman el módulo se corresponde con un grado de funcionalidad del mismo. El módulo tiene una parte actuada de 3gdl configurados en forma de junta esférica. Posee además dos prismas a los lados de la junta anterior donde va colocada la electrónica y demás componentes. Además de junta actuada se describe la estructura mecánica del resto del prototipo. También se describe la electrónica de a bordo diseñada. En la parte de simulación se explica la arquitectura del simulador desarrollado y sus principales características. Por último se tratan los elementos que forman el sistema global y como se comunican entre sí. Palabras Clave: Robots modulares, control distribuido, canales de comunicación.

Cutting Edge Robotics 2010, 2010

Computer Methods in …, 2010

This work focuses on obtaining realistic human hand models that are suitable for manipulation tas... more This work focuses on obtaining realistic human hand models that are suitable for manipulation tasks. A 24 degrees of freedom (DoF) kinematic model of the human hand is defined. The model reasonably satisfies realism requirements in simulation and movement. To achieve realism, intra- and inter-finger constraints are obtained. The design of the hand model with 24 DoF is based upon a morphological, physiological and anatomical study of the human hand. The model is used to develop a gesture recognition procedure that uses principal components analysis (PCA) and discriminant functions. Two simplified hand descriptions (nine and six DoF) have been developed in accordance with the constraints obtained previously. The accuracy of the simplified models is almost 5% for the nine DoF hand description and 10% for the six DoF hand description. Finally, some criteria are defined by which to select the hand description best suited to the features of the manipulation task.

The ability to perceive a three dimensional view of a remote workspace is an essential factor for... more The ability to perceive a three dimensional view of a remote workspace is an essential factor for teleoperation performance. In this chapter we present a novel class of 3D video interfaces that actively control the image acquisition system geometry to improve the ...

Sensors

Motion tracking techniques have been extensively studied in recent years. However, capturing move... more Motion tracking techniques have been extensively studied in recent years. However, capturing movements of the upper limbs is a challenging task. This document presents the estimation of arm orientation and elbow and wrist position using wearable flexible sensors (WFSs). A study was developed to obtain the highest range of motion (ROM) of the shoulder with as few sensors as possible, and a method for estimating arm length and a calibration procedure was proposed. Performance was verified by comparing measurement of the shoulder joint angles obtained from commercial two-axis soft angular displacement sensors (sADS) from Bend Labs and from the ground truth system (GTS) OptiTrack. The global root-mean-square error (RMSE) for the shoulder angle is 2.93 degrees and 37.5 mm for the position estimation of the wrist in cyclical movements; this measure of RMSE was improved to 13.6 mm by implementing a gesture classifier.

This paper describes dynamic constraints of a human hand model. Inter-finger and intra-finger con... more This paper describes dynamic constraints of a human hand model. Inter-finger and intra-finger constraints have been develop in order to obtain quite realistic manipulation.

Advances in Intelligent Systems and Computing, 2019

This paper presents ExoFlex, an upper-limb flexible exoskeleton (exosuit) intended for assistance... more This paper presents ExoFlex, an upper-limb flexible exoskeleton (exosuit) intended for assistance in elbow and shoulder rehabilitation therapies. The soft nature of the device allows it to easily adapt to human biomechanics. The presented exosuit is equipped with a cable-driven transmission in which torque is generated by two direct current (DC) motors. A super-twisting sliding mode controller (SMC) has been simulated and implemented for elbow and shoulder flexion and extension movements. ExoFlex has proven to effectively assist its wearer in experimental tests.

2021 IEEE 2nd International Conference on Human-Machine Systems (ICHMS), 2021

Flexible exoskeletons are lightweight robots that surround the user’s anatomy to assist or oppose... more Flexible exoskeletons are lightweight robots that surround the user’s anatomy to assist or oppose motion. Their structure is made of light and flexible materials, like fabrics, so the forces created by the robot are directly transferred to the user’s musculoskeletal system. Exosuits are thus sensitive to the sliding of the actuation, textile perturbations and improper fitting to the user. LUXBIT is a cable-driven flexible exoskeleton that combines fabrics and sewing patterns to promote its anatomical adaption. The exoskeleton is intended for bimanual assistance of daily tasks and long-term usage. To this end, the system reduces the pressures applied to the user and the misalignment of the actuation by stacking textile patches. The patches enhance the functioning of the base garment and promote the transference of the assistance forces. Additionally, LUXBIT has a compact actuation with deformable components to prevent the user movements from being restricted. The exoskeleton is portable by using an enhanced textile backpack. This paper shows the exoskeleton’s benefits for trajectory and muscle activity during the flexion of the shoulder and the elbow.

Lecture Notes in Computer Science

2008 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2008

This work is focused on obtaining efficient human hand models that are suitable for manipulation ... more This work is focused on obtaining efficient human hand models that are suitable for manipulation tasks. A 24 DoF kinematic model of the human hand is defined to realistic movements. This model is based on the human skeleton. Dynamic and Static constraints have been included in order to improve the movement realism. Two simplified hand models with 9 and 6 DoF have been developed according to the constraints predefined. These simplified models involve some errors in reconstructing the hand posture. These errors are calculated with respect to the 24 DoF model and evaluated according to the hand gestures. Finally, some criteria are defined to select the hand description best suited to the features of the manipulation task.

IEEE Transactions on Instrumentation and Measurement, 2011

This paper describes data processing using a haptic interface for virtual object grasping tasks. ... more This paper describes data processing using a haptic interface for virtual object grasping tasks. The haptic interface known as MasterFinger-2 (MF-2) is used. This haptic device enables the simulation of object manipulation using the thumb and index finger, which are inserted within thimbles located at the far end of the haptic interface. The experiments were conducted using a setup that provides the operator with two MF-2s. This setup enables bimanual virtual object manipulation. The haptic device provides data about the angular position of all joints and data from four contact sensors located within the thimbles. The values obtained from the angular positions of the joints enable a calculation of the position and orientation of the thimbles, whereas the values obtained from the contact sensors are used to formulate an approximate calculation of the user's force during object manipulation. This information regarding forces enables the segmentation of manipulation tasks and is essentially based on the rising edges produced by the contact sensor signals. After performing task segmentation, the state of the task in progress is detected. This facilitates improvements in user interaction because restrictions can be established in the relationships between the objects that change dynamically depending on the stage of manipulation. This information allows for an improvement in the realism of the simulation because the forces reflected take into account how the relationships between objects vary over the course of the task. Task segmentation is also used to ascertain objects' physical properties. These features are then used to simulate virtual objects with the same properties.

IEEE Robotics & Automation Magazine, 2008

Human visual mechanisms are well described in the literature [7], [8]. Howard and Rogers give an ... more Human visual mechanisms are well described in the literature [7], [8]. Howard and Rogers give an excellent review of the main

This paper describes dynamic constraints of a human hand model. Inter-finger and intra-finger con... more This paper describes dynamic constraints of a human hand model. Inter-finger and intra-finger constraints have been develop in order to obtain quite realistic manipulation. Keywords--human hand model, inter-finger, intrafinger, constraints.

This study presents the development of a wearable device that merges capacitive soft-flexion and ... more This study presents the development of a wearable device that merges capacitive soft-flexion and surface electromyography (sEMG) sensors for the estimation of shoulder orientation and movement, evaluating five natural movement gestures of the human arm. The use of Time Series Networks (TSN) to estimate the arm orientation, and a pattern recognition method for the estimation of the classification of the gesture are proposed. It is demonstrated that it is possible to know the orientation of the shoulder, and that the algorithm is capable of recognising the five gestures proposed with two different configurations. The study is performed on people who reported healthy upper limbs.

Journal of Physics: Conference Series

Flexible exoskeletons, also known as exosuits, are robotic wearable devices intended to help heal... more Flexible exoskeletons, also known as exosuits, are robotic wearable devices intended to help healthy and unhealthy subjects in different tasks, such as daily life activities, load lifting or rehabilitation. A position control is required to assure stability and compliance in all assisted movements. In this paper, the authors propose the use of a flexible position sensor based on differential capacitance measurement as position feedback for the elbow joint in the flexible exoskeleton LUXBIT. This exosuit is controlled in position by a super-twisting sliding mode controller (SMC), which is robust against disturbances. Different movements involved in rehabilitation therapies are performed over three healthy subjects in order to evaluate the exosuit performance using this motion sensor. The measures given by the flexible sensor are compared to the ones obtained by OptiTrack motion capture system, which are used as ground truth.

Sensors

Recovery of therapeutic or functional ambulatory capacity in patients with rotator cuff injury is... more Recovery of therapeutic or functional ambulatory capacity in patients with rotator cuff injury is a primary goal of rehabilitation. Wearable powered exoskeletons allow patients to perform repetitive practice with large movements to maximize recovery, even immediately after the acute event. The aim of this paper is to describe the usability, acceptability and acceptance of a hybrid exoskeleton for upper-limb passive rehabilitation using the System Usability Scale (SUS) questionnaire. This equipment, called ExoFlex, is defined as a hybrid exoskeleton since it is made up of rigid and soft components. The exoskeleton mechanical description is presented along with its control system and the way motion is structured in rehabilitation sessions. Seven patients (six women and one man) have participated in the evaluation of this equipment, which are in the range of 50 to 79 years old. Preliminary evidence of the acceptance and usability by both patients and clinicians are very promising, obta...

2020 IEEE International Conference on Human-Machine Systems (ICHMS)

Exoskeletons are human-machine interaction devices that can either assist or oppose the user’s mo... more Exoskeletons are human-machine interaction devices that can either assist or oppose the user’s motion. Soft exoskeletons are lightweight devices whose lack of rigid pieces provides them with soft behaviour. These exosuits use textiles and soft actuation mechanisms to enhance compliance and comfort during user interaction. The absence of a rigid structure, thereby, provokes drawbacks related to force transfer and fixation of the system to the wearer’s anatomy. Commonly-reported issues include textile-slippery phenomena, pressure-related discomfort, actuation perturbations due to muscle volume variability and joint misalignment during human motion. This paper introduces the fixation solution adopted in LuxBit, a textile-wearable cable-driven exoskeleton to assist elbow and shoulder flexion. Different textiles and sewing patterns are combined in this coupling-interface to promote force distribution and adaption to the wearer’s anatomy. Then, the document assesses the assistance capability of the device by measuring the trajectory and electromyography signals of four subjects while flexing the elbow and shoulder up to 90 degrees. The experiments also allow discussing the benefits for a healthy user in both cases, when carrying a 0.75kg load and not.

This paper presents the monitoring architecture and experience gained in a pilot distribution gri... more This paper presents the monitoring architecture and experience gained in a pilot distribution grid designed for continuous control of insulation condition of the grid by means of PD measurements. Powerful data processing tools are used for the discrimination of PD pulses from background noise, for locating different PD sources, for clustering PD sources and for identification of the defect associated to each PD source.

Sensors, 2015

Partial discharge (PD) measurements provide valuable information for assessing the condition of h... more Partial discharge (PD) measurements provide valuable information for assessing the condition of high voltage (HV) insulation systems, contributing to their quality assurance. Different PD measuring techniques have been developed in the last years specially designed to perform on-line measurements. Non-conventional PD methods operating in high frequency bands are usually used when this type of tests are carried out. In PD measurements the signal acquisition, the subsequent signal processing and the capability to obtain an accurate diagnosis are conditioned by the selection of a suitable detection technique and by the implementation of effective signal processing tools. This paper proposes an optimized electromagnetic detection method based on the combined use of wideband PD sensors for measurements performed in the HF and UHF frequency ranges, together with the implementation of powerful processing tools. The effectiveness of the measuring techniques proposed is demonstrated through an example, where several PD sources are measured simultaneously in a HV installation consisting of a cable system connected by a plug-in terminal to a gas insulated substation (GIS) compartment.

ABSTRACT Resumen Este artículo describe los trabajos realizados hasta la fecha en el desarrollo d... more ABSTRACT Resumen Este artículo describe los trabajos realizados hasta la fecha en el desarrollo del robot modular RobMAT. Se describe el módulo propuesto que equilibra complejidad con prestaciones; es decir la dificultad de diseño e integración de los elementos que forman el módulo se corresponde con un grado de funcionalidad del mismo. El módulo tiene una parte actuada de 3gdl configurados en forma de junta esférica. Posee además dos prismas a los lados de la junta anterior donde va colocada la electrónica y demás componentes. Además de junta actuada se describe la estructura mecánica del resto del prototipo. También se describe la electrónica de a bordo diseñada. En la parte de simulación se explica la arquitectura del simulador desarrollado y sus principales características. Por último se tratan los elementos que forman el sistema global y como se comunican entre sí. Palabras Clave: Robots modulares, control distribuido, canales de comunicación.

Cutting Edge Robotics 2010, 2010

Computer Methods in …, 2010

This work focuses on obtaining realistic human hand models that are suitable for manipulation tas... more This work focuses on obtaining realistic human hand models that are suitable for manipulation tasks. A 24 degrees of freedom (DoF) kinematic model of the human hand is defined. The model reasonably satisfies realism requirements in simulation and movement. To achieve realism, intra- and inter-finger constraints are obtained. The design of the hand model with 24 DoF is based upon a morphological, physiological and anatomical study of the human hand. The model is used to develop a gesture recognition procedure that uses principal components analysis (PCA) and discriminant functions. Two simplified hand descriptions (nine and six DoF) have been developed in accordance with the constraints obtained previously. The accuracy of the simplified models is almost 5% for the nine DoF hand description and 10% for the six DoF hand description. Finally, some criteria are defined by which to select the hand description best suited to the features of the manipulation task.

The ability to perceive a three dimensional view of a remote workspace is an essential factor for... more The ability to perceive a three dimensional view of a remote workspace is an essential factor for teleoperation performance. In this chapter we present a novel class of 3D video interfaces that actively control the image acquisition system geometry to improve the ...

Sensors

Motion tracking techniques have been extensively studied in recent years. However, capturing move... more Motion tracking techniques have been extensively studied in recent years. However, capturing movements of the upper limbs is a challenging task. This document presents the estimation of arm orientation and elbow and wrist position using wearable flexible sensors (WFSs). A study was developed to obtain the highest range of motion (ROM) of the shoulder with as few sensors as possible, and a method for estimating arm length and a calibration procedure was proposed. Performance was verified by comparing measurement of the shoulder joint angles obtained from commercial two-axis soft angular displacement sensors (sADS) from Bend Labs and from the ground truth system (GTS) OptiTrack. The global root-mean-square error (RMSE) for the shoulder angle is 2.93 degrees and 37.5 mm for the position estimation of the wrist in cyclical movements; this measure of RMSE was improved to 13.6 mm by implementing a gesture classifier.

This paper describes dynamic constraints of a human hand model. Inter-finger and intra-finger con... more This paper describes dynamic constraints of a human hand model. Inter-finger and intra-finger constraints have been develop in order to obtain quite realistic manipulation.