Philipp Beckerle

Philipp Beckerle
Friedrich-Alexander-University of Erlangen-Nürnberg | FAU · Chair of Autonomous Systems and Mechatronics

Prof. Dr.-Ing. habil.

About

140
Publications
34,823
Reads
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1,379
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Introduction
Philipp Beckerle received his Dr.-Ing. in mechatronics from TU Darmstadt, Germany, in 2014 and his habilitation from TU Dortmund, Germany, in 2021. He is full professor and chair of Autonomous Systems and Mechatronics at FAU Erlangen-Nürnberg (www.asm.tf.fau.de) and was visiting researcher at Vrije Universiteit Brussel, Arizona State University, and University of Siena. His research interest is in human-centered mechatronics and robotics and his work was honored with various awards.

Publications

Publications (140)
Article
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Traditionally, robotics and psychology have little to share; at least, if we think of robotics as an endeavor to build machines able to autonomously perform tasks that are undesirable or impossible for human beings. Nevertheless, besides addressing safety requirements for close physical interaction, which are tackled by approaches like soft robotic...
Chapter
In real-world applications, wearable robots need to serve functional requirements, but also satisfy user demands. A systematic evaluation will require multidisciplinary benchmarking methods. Since user experience seems to be of distinct relevance, this paper analyzes how user experience influences wearable robots use and how it can be considered in...
Chapter
To support human motions, wearable robots tightly interact with their human users. Besides demanding for functional assistance, user experience is of paramount importance. Remarkably, both aspects are subject to inter-individual differences and, hence, call for personalized solutions. This paper outlines how to address this challenge combining appr...
Article
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Using the seminal rubber hand illusion and related paradigms, the last two decades unveiled the multisensory mechanisms underlying the sense of limb embodiment, that is, the cognitive integration of an artificial limb into one's body representation. Since also individuals with amputations can be induced to embody an artificial limb by multimodal se...
Article
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Personalization of gait neuroprosthetics is paramount to ensure their efficacy for users, who experience severe limitations in mobility without an assistive device. Our goal is to develop assistive devices that collaborate with and are tailored to their users, while allowing them to use as much of their existing capabilities as possible. Currently,...
Chapter
Summarizing and discussing the contents of the previous chapters, we provide biological, engineering, bioinspiration, and application considerations of bioinspired actuators for robotics.
Chapter
In this chapter, the basic mechanical setup is described and its potential for human-machine interaction and how it can be leveraged by design and hardware integration is discussed.
Article
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The day seems not too far away, in which robots will be an active part of our daily life, just like electric appliances already are. Hence, there is an increasing need for paradigms, tools, and techniques to design proper human-robot interaction in a human-centered fashion (Beckerle et al., 2017). To this end, appropriate Human-Machine Interfaces (...
Book
This monograph presents innovative research regarding the body experience of human individuals who are using assistive robotic devices such as wearable robots or teleoperation systems. The focus is set on human-in-the-loop experiments that help to empirically evaluate how users experience devices. Moreover, these experiments allow for further exami...
Article
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Previous research has shown the value of the sense of embodiment, i.e., being able to integrate objects into one’s bodily self-representation, and its connection to (assistive) robotics. Especially, tactile interfaces seem essential to integrate assistive robots into one’s body model. Beyond functional feedback, such as tactile force sensing, the h...
Chapter
While a large body of research investigates upper limb bodily experience, knowledge concerning the lower limbs is similarly important and can benefit from human-in-the-loop experiments. This chapter inquires specific requirements, presents an appropriate system design, and confirms the transferability of robotic limb illusions to the lower limbs. A...
Chapter
Besides considering human-robot body experience as a metric in robot and control design, understanding it in a broader sense and context is of psychological and technical interest. This chapter discusses the potential of cognitive models of body experience in robotics. Approaches like Bayesian or connectionist models might enable adapting assistive...
Chapter
Understanding the embodiment of robotic devices and using this knowledge to improve human-robot interaction touches a variety of open research questions. A considerable body of research outlines the complexity and plasticity of human bodily experience. When examining robotic devices, which can be seen as “intelligent” tools, this challenge is getti...
Chapter
Haptic interaction plays a crucial role in achieving the embodiment of robotic devices. This chapter suggests future research directions with respect to bi-directional human-machine interfaces and considering the whole variety of the sense of touch. Aiming at robotic devices that “feel good”, robots equipped with bi-directional human-machine interf...
Chapter
Augmenting rubber hand illusion paradigms extends experimental possibilities and can disentangle human action-perception loops. This chapter presents technical and experimental merits with a focus on tactile feedback and the influence of delays. A pilot study proofs the applicability of the RobHI setup with tactile feedback. Additionally, two exten...
Chapter
Promoting technical means advances the experimental possibilities to probe human-robot body experience and improves implementing the target applications. This chapter discusses practical approaches towards wireless sensing and feedback as well as integrating psychophysiological measurement. Even with low-cost solutions, current technology holds a s...
Chapter
Similar to robotic approaches, virtual hand illusion (VHI) experiments enable deeper insights into human-robot body experience. This chapter discusses the influence of different haptic feedback modalities as well as interrelations to autonomy and controllability. The first study compares wearable force feedback, vibrotactile feedback, and no haptic...
Article
Full-text available
Generalizing the operation of robots in dynamical environments regardless of the task complexity is one of the ultimate goals of robotics researchers. Learning from demonstration approaches supported by transfer learning and user feedback offer a remarkable solution to achieve generalization. The main idea behind such approaches is teaching robots...
Book
This book discusses biologically inspired robotic actuators designed to offer improved robot performance and approaching human-like efficiency and versatility. It assesses biological actuation and control in the human motor system, presents a range of technical actuation approaches, and discusses potential applications in wearable robots, i.e., pow...
Article
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The large-scale adoption of occupational exoskeletons (OEs) will only happen if clear evidence of effectiveness of the devices is available. Performing product-specific field validation studies would allow the stakeholders and decision-makers (e.g., employers, ergonomists, health, and safety departments) to assess OEs’ effectiveness in their specif...
Article
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People with physical disabilities in their upper extremities face serious issues in using classical input devices due to lacking movement possibilities and precision. This article suggests an alternative input concept and presents corresponding input devices. The proposed interface combines an inertial measurement unit and force sensing resistors,...
Chapter
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Elastic actuators can provide safe human-robot interaction and energy efficient mobility. For this purpose they are ideal for wearable robotic applications. However, such actuators are subject to stiffness faults. We present a stiffness-fault-tolerant control strategy for complex elastic actuators, capable of adapting to changes in output stiffness...
Article
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Wearable robots (WRs) are increasingly moving out of the labs towards real-world applications. In order for WRs to be effectively and widely adopted by end-users, a common benchmarking framework needs to be established. In this article, we outline the perspectives that in our opinion are the main determinants of this endeavour, and exemplify the co...
Chapter
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We present a wearable vibrotactile feedback device consisting of four linear resonant actuators (LRAs) that are able to generate virtual stimuli, known as phantom tactile sensation, for human-robot interaction. Using an energy model, we can control the location and intensity of the virtual stimuli independently. The device consists of mostly 3D-pri...
Article
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Cognitive modeling of human behavior has advanced the understanding of underlying processes in several domains of psychology and cognitive science. In this article, we outline how we expect cognitive modeling to improve comprehension of individual cognitive processes in human-agent and, particularly, human-robot interaction. We argue that cognitive...
Article
Background A variety of instruments exist to measure human factors for lower limb amputation and prosthesis research yet, there is no valid or reliable tool available that focuses on technical potentials. Objective This study aimed to validate and revise the Questionnaire to Explore Human Factors and their Technical Potential. Study Design Cross-...
Article
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Redundancy facilitates some of the most remarkable capabilities of humans, and is therefore omni-present in our physiology. The relationship between redundancy in robotics and biology is investigated in detail on the Series Elastic Dual-Motor Actuator (SEDMA), an actuator inspired by the kinematic redundancy exhibited by myofibrils. The actuator co...
Article
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Subjective experience of human control over remote, artificial, or virtual limbs has traditionally been investigated from two separate angles: presence research originates from teleoperation, aiming to capture to what extent the user feels like actually being in the remote or virtual environment. Embodiment captures to what extent a virtual or arti...
Article
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Torsion adapters in lower limb prostheses aim to increase comfort, mobility and health of users by allowing rotation in the transversal plane. A preliminary study with two transtibial amputees indicated correlations between torsional stiffness and foot alignment to increase comfort and stability of the user depending on the gait situation and veloc...
Article
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In the advent of intelligent robotic tools for physically assisting humans, user experience, and intuitiveness in particular have become important features for control designs. However, existing works predominantly focus on performance-related measures for evaluating control systems as the subjective experience of a user by large cannot be directly...
Chapter
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Elastic actuators are popular in human-robot interaction as they can improve human safety and efficiency. Yet, such actuators are more complex than rigid ones and might be subject to additional technical faults, e.g., stiffness changes. This paper extends previous studies on stiffness-fault-tolerant physical human-robot interaction (pHRI) through c...
Article
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Daily human activity is characterized by a broad variety of movement tasks. This work summarizes the sagittal hip, knee, and ankle joint biomechanics for a broad range of daily movements, based on previously published literature, to identify requirements for robotic design. Maximum joint power, moment, angular velocity, and angular acceleration, as...
Article
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Objective To explore user-centered design methods currently implemented during development of lower limb wearable robots and how they are utilized during different stages of product development. Background Currently, there appears to be a lack of standardized frameworks for evaluation methods and design requirements to implement effective user-cen...
Chapter
The main purpose of this study was to identify outcome measures that developers working in the area of wearable robots utilize during different phases of product development. Experts in the field were invited to complete a short, anonymous, online survey. The results presented in this study focus on answers that engineers working on exoskeletons fo...
Conference Paper
Full-text available
Assistive robotic devices recently receive strong interest in fundamental as well as applied research. Beyond their potential for ageing societies, they foster understanding human cognition through technical extensions of experimental paradigms from psychology, neuroscience, and cognitive science, e.g., virtual and robotic versions of the Rubber Ha...
Article
Bayesian cognitive modeling has become a prominent tool for the cognitive sciences aiming at a deeper understanding of the human mind and applications in cognitive systems, e.g., humanoid or wearable robotics. Such approaches can capture human behavior adequately with a focus on the crossmodal processing of sensory information. The rubber foot illu...
Article
This review paper aims to develop a knowledge base and identify promising research pathways toward designing lower limb prostheses for optimal biomechanical and clinical outcomes. It is based on a literature search representing the state-of-the-art in lower limb prosthesis joint design and biomechanical analysis. Current design solutions are organi...
Article
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Active compliant control enables to quickly and freely adjust the properties and dynamic behavior of interactions of mechanisms within certain limits. According to the emerging applications in many robotic fields and related areas, the number of publications has also strongly increased. This paper meets the need for a recent comprehensive review, i...
Article
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The relative motion between residual limb and prosthetic socket could be a relevant factor in quantifying socket fit. The measurement of these movements, particularly in dynamic gait situations, poses a challenging task. This paper presents the realization of a measurement concept based on multiple optical 2D-motion sensors. The performance of the...
Conference Paper
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Wearable robots are artifacts made to be used by human users in tight interaction. While supporting the user certainly requires specific functionalities from such devices, human factors are usually harder to grasp for the developer, but obviously of utmost importance. Recent research on upper limb as well as lower limb devices tries to improve the...
Chapter
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Selected practice problems in the format of numerical problems, concept questions, and case studies are presented in this chapter. Each problem is labeled with an estimated level of difficulty and list of most relevant chapters. Solutions and hints for about half of these problems are provided in the following chapter.
Chapter
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This chapter discusses natural and synthetic muscles as well as other human made actuators. A comprehensive review and comparison of biological and synthetic motor units at different levels and scales are provided. The study of actuation is quite relevant in the context of biomechatronics research. In order to decide how best to interface with a bi...
Chapter
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Replacing missing body parts by biomechatronic systems is a very challenging aspect of engineering. Yet, well-designed devices have huge potential to improve the quality of life of their users. This chapter gives a broad introduction and deeper insight into prosthetic limbs. It outlines the current demographic and societal situation and development...
Article
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In the last decades, cognitive models of multisensory integration in human beings have been developed and applied to model human body experience. Recent research indicates that Bayesian and connectionist models might push developments in various branches of robotics: assistive robotic devices might adapt to their human users aiming at increased dev...
Article
Full-text available
The question how humans integrate artificial lower limb devices into their body schema has distinct potential for engineering motion assistance systems, e.g., the design of robotic prostheses. Adding robotic technology to existing psychological experiments enables a deeper investigation of multisensory interaction between proprioceptive, visual, an...
Article
Elastic actuators feature increased energy efficiency and improved human-robot interaction compared to directly driven concepts for active orthoses and prostheses. Structure and parameters of the elastic actuation system are often designed via a model-based minimization of energy consumption based on gait data gained from healthy individuals. Howev...
Article
The cover image is based on the Focus Article Robotic interfaces for cognitive psychology and embodiment research: a research roadmap, by Philipp Beckerle, Claudio Castellini, and Bigna Lenggenhager, https://doi.org/10.1002/wcs.1486. The cover image is based on the Focus Article Robotic interfaces for cognitive psychology and embodiment research: a...
Article
Full-text available
In this paper, we present the kinematically redundant Series Elastic Dual-Motor Actuator (SEDMA). It consists of two motors, coupled to a series spring through a planetary differential. The redundant degree of freedom of this system can be exploited to optimize a specific aspect of the actuation task. This requires a controller which distributes th...
Article
Full-text available
The rubber hand illusion describes a phenomenon in which participants experience a rubber hand as being part of their body by the synchronous application of visuotactile stimulation to the real and the artificial limb. In the recently introduced robotic hand illusion (RobHI), a robotic hand is incorporated into one's body representation due to the...
Data
Archive containing acquired raw data (questionnaire scores and proprioceptive drift) for each experiment. (ZIP)
Article
This study introduces a novel approach for evaluating the quality of human-in-the-loop control using the psychological construct of embodiment in a haptic human-machine interaction task. Despite the fact that various forms of assistive control have been introduced, these methods mainly design semi-autonomous control to improve task-specific interac...
Article
Full-text available
Increasing presence is one of the primary goals of virtual reality research. A crucial aspect is that users are capable of distinguishing their self from the external virtual world. The hypothesis we investigate is that wearable haptics play an important role in the body experience and could thereby contribute to the immersion of the user in the vi...
Conference Paper
This study introduces a novel approach for evaluating the quality of human-in- the-loop control using the psychological construct of embodiment in a haptic human-machine interaction task. Despite the fact that various forms of assistive control have been introduced, these methods mainly design semi-autonomous control to improve task-specific intera...
Article
Advanced human–machine interfaces render robotic devices applicable to study and enhance human cognition. This turns robots into formidable neuroscientific tools to study processes such as the adaptation between a human operator and the operated robotic device and how this adaptation modulates human embodiment and embodied cognition. We analyze bid...
Article
Full-text available
The feeling of embodiment, i.e., experiencing the body as belonging to oneself and being able to integrate objects into one’s bodily self-representation, is a key aspect of human self-consciousness and has been shown to importantly shape human cognition. An extension of such feelings towards robots has been argued as being crucial for assistive tec...
Article
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Template models of legged locomotion are powerful tools for gait analysis, but can also inspire robot design and control. In this paper, a spring-loaded inverted pendulum (SLIP) model is employed to control vertical hopping of a 2-segmented legged robot. Feed-forward and bio-inspired virtual model control using the SLIP model are compared. In the l...
Conference Paper
The main purpose of this study was to identify outcome measures that developers working in the area of wearable robots utilize during different phases of product development. Experts in the field were invited to complete a short, anonymous, online survey. The results presented in this study focus on answers that engineers working on exoskeletons fo...
Conference Paper
For individuals having a motor disorder of neuromuscular origin, computer usage can be challenging. Due to different medical conditions, alternative input methodologies such as speech or eye tracking are no option. Here, piezo sensors, inertial measurement units and force resistance sensors are used to develop input devices that can compensate for...
Conference Paper
Perturbations are used to study and identify mechanisms of human motor control. This study introduces a concept for a movement manipulator prototype to explore human response and recovery strategies following temporary perturbations at the local joint level. We utilized a soft humanmachine interface in combination with a tethered actuation unit to...
Article
Full-text available
A sensor system for measuring the relative movement between prosthetic socket and residual limb based on a 2D-motion sensor is introduced and thoroughly tested experimentally. The quantitative analysis of test rig evaluation is used to identify advantageous sensor settings and liner configurations. Considering these favorable settings, sensor funct...
Conference Paper
The robotic hand illusion is a variant of the classical rubber hand illusion in which the embodiment of an artificial hand into one's own body-representation is induced via multisensory and sensorimotor coherence. This paper elaborates on the design and implementation of a wearable robotic hand/arm-system in which sensorimotor aspects can be manipu...
Article
Full-text available
Legged robots are an efficient alternative for navigation in challenging terrain. In this paper we describe Weaver, a six legged robot that is designed to perform autonomous navigation in unstructured terrain. It uses stereo vision and proprioceptive sensing based terrain perception for adaptive control while using visual-inertial odometry for auto...
Article
A better understanding of human body experience and the embodiment of arti- ficial limbs could path the way towards a novel generation of robotic hands. Such hands could serve as assistive devices, which closely matching users’ expectations and needs. Knowledge about the users sensory-motor skills can additionally guide techni- cal developments, e....
Conference Paper
A declared aim in prosthetic research is enabling physical and psychological integration of robotic limbs into a user»s body schema. The rubber hand illusion (RHI) gives insight into the impact of sensory feedback and its multisensory integration on embodiment which can be used in wearable robot design, e. g. prosthetic hands. This paper presents a...
Article
This paper proposes a probabilistic approach for the design of elastic elements to be used in structure-controlled variable stiffness actuators for robotic applications. Considering the natural dynamics of the elastic actuation system, requirements are defined and material selection as well as geometry calculation are performed using lumped paramet...
Article
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Variable elastic actuators are very promising for applications in physical human–robot interaction. Besides enabling human safety, such actuators can support energy efficiency, especially if the natural behavior of the system is exploited. In this paper, the power and energy consumption of variable stiffness actuators with serial elasticity is inve...
Article
Full-text available
For people with lower limb amputation, a user-specific human-machine interaction with their prostheses is required to ensure safe and comfortable assistance. Especially during dynamic turning manoeuvres, users experience high loads at the stump, which decreases comfort and may lead to long-term tissue damage. Preliminary experiments with users wear...
Article
This Special Issue gives a comprehensive and in-depth overview of current technical developments, neural and psychological background, requirement definitions, structured assessment in user studies, human-oriented design methods, and wearable robotic applications. Technically, this concerns systems engineering as well as the design of components su...
Article
Robotic systems using elastic actuators provide safe human-robot interaction and energy-efficient operation. Since increased complexity and critical operation states could foster fault occurrence, this paper investigates faults in elastically-actuated robots. To identify and assess relevant faults, expert opinions from an online survey are statisti...
Article
Full-text available
Assistive and rehabilitation devices are a promising and challenging field of recent robotics research. Motivated by societal needs such as aging populations, such devices can support motor functionality and subject training. The design, control, sensing, and assessment of the devices become more sophisticated due to a human in the loop. This paper...