Optimal Grip Research Articles

Combining finite element analysis and reinforcement learning for optimal grip point planning of flexible components

Abstract Handling large flexible components is still a challenge in many industries. Examples include the handling of fibre-reinforced plastics or the assembly of industrial-scale electrolytic cells. Difficulties often arise in the design of suitable endeffectors. Inefficient gripping point design, i.e. the total number and positioning of grippers, can lead to increased stress and deflection of the component being handled. To counteract this, endeffectors are often oversized resulting in the use of more grippers than needed. Correspondingly, heavier moving masses imply longer handling times as well as higher energy consumption. This paper presents a process for planning and optimising gripping points for large flexible components. In addition to the shape of the component, actual dynamic loads of the handling path are also taken into account. The key element to the process is an optimisation algorithm based on reinforcement learning and trained using an finite element method (FEM) simulation. After computing a desirable starting configuration, the algorithm optimises the placement of gripper positions while aiming for a reduced total number. In addition, the optimisation has prescribed handling limits, such as physical and geometric constraints, that must not be exceeded. It was shown that the algorithm satisfactorily optimises the gripping points for dynamic loads for different materials and shapes. Furthermore, it has been shown that the computation of an initial configuration yields preferable results for simple components, yet requiring optimisation in the case of more complex shapes.

Arthroplasty of the proximal interphalangeal joint of the hand: the current state of the problem

Introduction The proximal interphalangeal joint (PIP joint) plays an important role in ensuring optimal finger dexterity, grip strength and overall hand functionality. Arthroplasty is a promising direction in the surgical treatment of arthritis of the PIP joint of the hand, however, the inconsistency of the results encourages the world scientific community to be restrained and further investigate the problems associated with PIP joint arthroplasty.The purpose of the work was to identify the main problems of PIP joint arthroplasty based on the analysis of foreign and domestic medical literature.Materials and methods In this literature review, an analysis of foreign and domestic scientific publications devoted to the treatment of diseases and injuries of PIP joint was carried out. The purpose of the study was to provide a brief historical background and identify the main problems of PIP joint arthroplasty based on the analysis of foreign and domestic medical literature.Results and discussion The choice of the implant and the surgical aproach used are the two most frequently discussed issues in PIP joint arthroplasty; dorsal, palmar and lateral surgical approaches are described, each with its own advantages and disadvantages. Dorsal approaches are used most often because they are easier to perform; however, the fragile extensor apparatus is damaged with the subsequent development of extensor lag. A number of authors concluded that stiffness and extensor lag were the most common postoperative complications. Several combinations of materials are available: from classic chrome-cobalt/polyethylene to ceramic/ceramic and pyrocarbon/pyrocarbon. Most of them have not stood the test of time yet, and for most implants there is still a lack of real long-term monitoring series for survival of the design.Conclusion The morphology of joints, small bone sizes, complex biomechanics and the load on the hand are a special problem in PIP joint arthroplasty. It is still not possible to restore the full range of motion in this joint, despite the success of colleagues in arthroplasty of large joints.

Ambient smart environments: affordances, allostasis, and wellbeing

In this paper we assess the functionality and therapeutic potential of ambient smart environments. We argue that the language of affordances alone fails to do justice to the peculiar functionality of this ambient technology, and draw from theoretical approaches based on the free energy principle and active inference. We argue that ambient smart environments should be understood as playing an'upstream' role, shaping an agent's field of affordances in real time, in an adaptive way that supports an optimal grip on a field of affordances. We characterise this optimal grip using precision weighting, and in terms of allostatic control, drawing an analogy with the role of precision weighting in metacognitive processes. One key insight we present is that ambient smart environments may support allostatic control not only by simplifying an agent's problem space, but by increasing uncertainty, in order to destabilise calcified, sub-optimal, psychological and behavioural patterns. In short, we lay an empirically-grounded theoretical foundation for understanding ambient smart environments, and for answering related philosophical questions around agency, trust, and subjective wellbeing.

How Does Embodiment Enable the Acquisition of Tacit Knowledge in Organizations? From Polanyi to Merleau-Ponty

We address the question of how embodiment enables tacit knowledge acquisition in the workplace. Although references to tacit knowledge in organizational research are common, we still lack a refined theoretical account of how tacit knowledge is acquired, especially in relation to embodiment. Following Polanyi, we start with the premise that to know something tacitly implies a movement from subsidiary to focal awareness. We provide a process account of how embodiment enables tacit knowledge acquisition, by developing further Polanyi’s insights through Merleau-Ponty’s phenomenology and phenomenologically oriented cognitive science. We argue that tacit knowledge is inferred to exist when fluency is manifested in task-specific performance. In particular, task-specific tacit knowledge is acquired once the objective body, having engaged in indwelling, is co-operatively turned to a phenomenal body that develops focal/subsidiary awareness and task-specific body schemas. The phenomenal body is capable of responding to the solicitations of the task at hand, thus striving to find an optimal grip on task-related particulars. This ability develops through authoritative guidance by more experienced others, in the effort to improve the fluency of task execution by focusing on and scrutinizing subsidiary particulars. We illustrate this process with several examples and discuss its implications for organizational research.

Getting a Grip on Normativity: A Phenomenological Response to Maslow’s Call for a “Humanistic Biology”

Maslow suggests that a study of “superior” human specimen might have the potential to identify biological traits that distinguish flourishing individuals from those who are languishing. Maslow’s recommendation is open to criticisms. First, his method is circular. Second, the thrust of Maslow’s project has a eugenic ring to it. However, while Maslow’s eugenic vision should be sidelined, his call for an understanding of normativity and the need to overcome the fact-value dichotomy in psychology and neuroscience are well-considered recommendations. A phenomenological approach to normativity presents a more authentically humanistic approach to consideration of normativity. Husserl’s concept of optimal givenness and Merleau-Ponty’s notion of maximum grip illustrate that normativity is a quality that can be identified at a pre-predicative, implicit level of operative intentionality. Based on an examination of the notions of optimal givenness and maximum grip, the article further suggests that, within the context of interpersonal relations, agapic love can be understood to operate as a normative and regulative idea for ethical relations. Since this form of intentionality instantiates itself into perceptual and motor habits, normative ethical relations may be subject to investigation within neuroscience, to the extent that it maintains an ongoing dialogue with phenomenology.

Functional outcomes and complications after treatment of distal radius fracture in patients sixty years and over: A systematic review and network meta-analysis

AimThis network meta-analysis aims to compare functional outcomes and complications between conservative treatment and surgery for distal radius fractures in patients aged 60 years and over. MethodsWe searched the PubMed, EMBASE, and Web of Science databases for randomized controlled trials (RCTs) assessing the effect of conservative treatment and surgery for distal radius fractures in patients aged 60 years and over. Primary outcomes included grip strength and overall complications. Secondary outcomes included Disabilities of the Arm, Shoulder, and Hand (DASH) scores, Patient-Rated Wrist Evaluation (PRWE) scores, wrist range of motion and forearm rotation, and radiographic assessment. All continuous outcomes were assessed using standardized mean differences (SMDs) with 95% confidence intervals (CIs), and binary outcomes were assessed using odds ratio (OR) with 95% CIs. The surface under the cumulative ranking curve (SUCRA) was used to determine a hierarchy of treatments. Cluster analysis was performed for grouping treatments based on the SUCRA values of primary outcomes. ResultsFourteen RCTs were included to compare conservative treatment, volar lockedplate (VLP), K-wires fixation, and external-fixation. VLP outperformed conservative treatment for 1-year and minimum 2-year grip strength (SMD; 0.28 [0.07 to 0.48] and 0.27 [0.02 to 0.53], respectively). VLP yielded the optimal grip strength at 1-year and minimum 2-year follow-up (SUCRA; 89.8% and 86.7%, respectively). In a subgroup analysis of patients aged 60 to 80 years old, VLP outperformed conservative treatment in DASH and PRWE scores (SMD, 0.33 [0.10, 0.56] and 0.23 [0.01, 0.45], respectively). In addition, VLP had the fewest complications (SUCRA = 84.3%). Cluster analysis suggested that VLP and K-wire fixation were more effective treatment groups. ConclusionEvidence to date demonstrates that VLP provides measurable benefits in grip strength and fewer complications to those 60 years of age and over, and that benefit is not reflected in current practice guidelines. There is a subgroup of patients where K-wire fixation outcomes are similar to those of VLP; defining this subgroup may yield substantial societal benefits.

On That <em>Toy-Being</em> of Generative Art Toys

On That <em>Toy-Being</em> of Generative Art Toys

Ecological-enactive account of autism spectrum disorder

Autism spectrum disorder (ASD) is a psychopathological condition characterized by persistent deficits in social interaction and communication, and restricted, repetitive patterns of behavior and interests. To build an ecological-enactive account of autism, I propose we should endorse the affordance-based approach of the skilled intentionality framework (SIF). In SIF, embodied cognition is understood as skilled engagement with affordances in the sociomaterial environment of the ecological niche by which an individual tends toward the optimal grip. The human econiche offers a whole landscape of affordances, and situated individuals respond to a field of relevant affordances. An important part of SIF is an ecological-enactive interpretation of the free energy principle and predictive processing. Predictive processing accounts indicate that in ASD too much precision is assigned to prediction errors. Autistic persons depend heavily on current sensory information and less on prior beliefs and cannot attune to stable regularities. To reduce uncertainty, they over-rely on routines, strict habits, and a familiar environment—a predictable ecological niche they construct. I argue that skilled intentionality gives us the framework from which to analyze the autistic field of affordances. Autistic patterns of affordance-related bodily states of action readiness are only sensitive to very specific solicitations in the environment and achieve optimal grip in well-known situations. Autism is to be understood as a disorder of bodily normativity. Taking this approach helps us figure out what neurotypical people can do to attune their environment in order to scaffold the needs of autistic individuals by redesigning the landscape of affordances.

Design of Flexible Spherical Fruit and Vegetable Picking End-effector Based on Vision Recognition

In order to solve the problems of poor versatility and high clamping damage rate faced by the end-effector of picking robots in today’s picking operation, a universal spherical fruit and vegetable picking die end-effector based on vision recognition with adaptive flexible force clamping is designed. This end-effector is a pneumatic three structure, while integrating a small air source device, in the control of a variety of sensors, through the fusion of multiple sensing and algorithm improvement and other ways, so that the mold end-effector in the picking operation, through visual recognition to determine the type of fruit and vegetables, and then provide the optimal gripping force. At the same time, the fingertip is equipped with a pressure sensor to adjust the pressure output in real time to achieve the overall picking process, the pressure is kept constant, and in the judgment of the completion of fruit and vegetable picking, a torque sensor is equipped to presume the completion of the picking operation by twisting the fruit strength. Finally, the actual product was made and several fruit and vegetable simulation experiments were carried out. The experimental structure is good, which verifies that the end-effector has good versatility and flexibility.

Optimal Grip Span for Measuring Maximum Handgrip Strength in Preschool Children

Background: Since the minimum grip span of a standard Smedley hand dynamometer is 4 cm, the handgrip strength (HGS) value at a less than 4 cm grip span has not been reported. Objective: The present study examined the impact of grip span on handgrip strength (HGS) in young children using a dynamometer ranging from 2 to 4.5 cm of grip span. Methods: A total of 93 (39 girls and 54 boys) children were recruited from a local kindergarten with the cooperation of their parents. Each participant performed one test trial and then five maximal trials using different grip spans (2.0, 3.0, 3.5, 4.0, and 4.5 cm) in random order and allowing a 1-minute rest between measures. Results: There was a statistically significant difference in HGS depending on which grip span was used, χ2(4) = 211.5 (p < 0.001). Mean ranks were 1.03, 2.79, 3.72, 3.94, and 3.53 for 2 cm, 3 cm, 3.5 cm, 4 cm, and 4.5 cm, respectively. Follow-up tests found statistically significant differences between each grip span comparison except for the 3.5 cm vs. 4.0 cm comparison (p = 0.166) and the 3.5 cm vs. 4.5 cm comparison (p = 0.611). Our finding showed that the highest HGS appeared at a grip span of 4.0 cm. In addition, the difference between HGS at a grip span of 4.0 cm and 3.5 cm or a grip span of 4.0 cm and 4.5 cm was statistically different but relatively small. Conclusion: Our results recommended that the target grip span for measuring maximal HGS in young children is about 4 cm (4 ± 0.5 cm).

Method of synthesis of optimal grip trajectories of a manipulator of an autonomous mobile robot

The features of the dynamics of an autonomous mobile robot of variable configuration with a relative motion of the manipulator are considered.&#x0D; To effectively perform technological operations by the AMR manipulator in extreme previously unknown conditions, it is advisable at the design stage to develop a database containing the optimal sequences of movements along generalized coordinates that ensure the movement of the gripper between the given initial and final points of the working space. Figs.: 3. Tabl.: 2. Refs.: 20 titles.

Moisture regulation in finger pad ridges can ensure optimal grip

Moisture regulation in finger pad ridges can ensure optimal grip

Three-finger grasp planning and experimental analysis of picking patterns for robotic apple harvesting

Operational efficiency is an important bottleneck in the industrialization of apple picking robots. The action planning of grasping and picking is key to improving the operational efficiency of picking robots. In this study, first, from the perspective of grip stability, the grasping positions of a three-finger end-effector were planned in two cases to determine an optimal three-finger grip posture: one that is parallel to the apple stem–calyx axis and the other being centripetal to the apple equatorial plane. Second, based on the gripping posture parallel to the apple stem-calyx axis, four picking patterns were designed: vertical pull, horizontal pull, vertical rotation, and rotation–horizontal pull. With the horizontal displacement, vertical displacement, and rotation angle as the main factors influencing the picking process, it was found through ABAQUS simulation software and the response surface analysis method that the rotation–horizontal pull pattern with the combination of horizontal displacement and rotation angle yields the minimum separation force for apple piking. With the three-fingered hand in the optimal grasping posture parallel to the stem–calyx, the four picking patterns were tested on a dedicated apple picking experimental device equipped with a grip force acquisition sensor, and the test results showed that the average three-finger grip force required for rotary tug-pull picking was the lowest (10.33 N). The proposed rotation–horizontal pull pattern with the three-finger grip posture was proven to be the best pattern for apple picking. The results of this study provide a theoretical basis for further research on apple picking robots.

Measurement and Co-Relation of Hand Span and Dexterity Function in Paediatric Population

&lt;strong&gt;Background&lt;/strong&gt;&lt;br&gt; The measure of handgrip strength is influenced by several factors including age, gender, different angle of shoulder, elbow,wrist and grip span . there is an optimal grip span at which maximum handgrip strength is obtained in adult.Hand span affect maximal and submaximal handgrip strengths. It was found that hand span affect grip strength, grip force and dexterity function in adult as well as geriatric population. In geriatric population hand grip function decreased with age.&lt;br&gt; &lt;strong&gt;Methodology&lt;/strong&gt;&lt;br&gt; Screening was done in 3 schools near PCMC area and students were selected as per the inclusion criteria. Total 150 children’s age from 6 to 16 years were selected from the convenient places. Hand span was measured in both hands (Dominant and Non-dominant) from the tip of the thumb to the tip of the small finger with the hand open as wide as possible. And the results of hand span measurement were rounded to nearest whole. The dexterity function was measured using Jebsen Taylor Hand Function Test. There were 7 subtests performed in the Jebsen Taylor Hand Function Test. &lt;br&gt; &lt;strong&gt;Results : &lt;/strong&gt;&lt;br&gt; The results shows that there was a strong negative correlation between the hand span and subtest1,2,3,7 of Jebsen Taylor Hand Function test. There was a moderate negative correlation between the subtest 4,5,6 of Jebsen Taylor Hand Function test. &lt;br&gt; &lt;strong&gt;Conclusion : &lt;/strong&gt;&lt;br&gt; In pediatrics, as the age increases, the hand span and hand grip strength increases but the time required to complete the subtest in Jebsen Taylor hand function test decreases. So the dexterity function improves.

Moral affordance, moral expertise, and virtue

We extend “4E” cognition to moral psychology. Since acting on affordances typically requires expertise, moral expertise, or virtue, is needed to act on moral affordances and to shape moral agency. Ethical rules and codes, often selected through a process of constraint satisfaction, are also involved in the detection and selection of moral affordances. We argue that individuals who act prudently possess moral expertise that allows them to remain in the “metastable zone” between mind and world, giving them an optimal grip on moral affordances and permitting wise judgement and action. We show how this can be explained via a noncognitivist, affordance-based account of the virtue phronesis (prudence). Our overall approach creates space for reciprocally causal accounts and prospection in explanations of human moral activity.

Optimization of robot gripping forces and worst case loading

We consider the optimization of the vector of gripping forces that support a known generalized force acting on the gripped object—a rigid body or a mechanism. Working in the framework of finite dimensional normed vector spaces and their dual spaces, the cost function to be minimized is assumed to be a norm on the space of gripping forces. We present an expression for the optimum which depends on the external force and the kinematics of the gripping system. Next, assuming that optimal gripping forces are applied using force control, and assuming that there is a bound on the norm of the admissible gripping forces, we characterize the largest norm of an external force that the gripping system may support, that is, the norm of the worst case loading that may be applied and still be supported. A few simple examples are given for the sake of illustration.

The Temporality of Maximal Grip: On Pragmatists’ Readings of Merleau-Ponty

In this article, I will pursue three aims. First, I would like to demonstrate the non-transcendental character of Merleau-Ponty’s phenomenology, namely, his claim that a strict division between a priori and a posteriori is an abstraction that derives from a more primordial unity that is given in our lived experience. I will criticize authors such as H. Dreyfus and T. Carman who treat the body and bodily character of our existence as a classical Kantian a priori that functions as a condition of experience without itself being a part of the experience. The claim I would like to defend in this regard is that reflections on the conditions of our experience must themselves be a part of our experience. The second task is to show how Merleau-Ponty’s analysis of temporality helps him to avoid this strict division between a priori and a posteriori. Based on this, I will elucidate some of the most obscure passages of Phenomenology of Perception. Finally, I will claim that the notion of optimal grip can neither be explained by the reference to our body, as Carman claims, or to brains, organisms and their copings with the environment, as Dreyfus argues. Instead, I will claim that the maximal grip is rather a consolidation or intensification of the temporal ecstasy.

The Loop Gripper: A Soft Gripper for Honeycomb Materials

Honeycomb materials are widely used as core layers of sandwich panels in the packaging, furniture, aviation, and space industry. To fulfill the varying requirements of the different applications, a wide range of materials, cell geometries, and cell sizes is used. In combination with comparably low stiffness, fragile cell walls, and large dimensions, the various properties make the automated gripping of honeycomb panels challenging. In this paper, a new concept for a soft gripper, based on adjustable threads, providing the flexibility and sensitivity needed for gripping honeycomb materials, is presented. Based on analysis and preliminary tests, a prototype is designed and built. A series of tests is performed to determine the optimal gripping parameters for different honeycomb materials, as well as to quantify the gripping force. The tests show the suitability of the concept for automated gripping of a wide variety of honeycomb types.

An Ethical Inquiry of the Effect of Cockpit Automation on the Responsibilities of Airline Pilots: Dissonance or Meaningful Control?

Airline pilots are attributed ultimate responsibility and final authority over their aircraft to ensure the safety and well-being of all its occupants. Yet, with the advent of automation technologies, a dissonance has emerged in that pilots have lost their actual decision-making authority as well as their ability to act in an adequate fashion towards meeting their responsibilities when unexpected circumstances or emergencies occur. Across the literature in human factor studies, we show how automated algorithmic technologies have wrestled control away from airline pilots. The inter-related ethical and pragmatic consequences resulting from such a dissonance are presented. This includes pilots serving as ‘legal sponges’, being caught in ‘moral crumple zones’, as well as real impacts on safety and well-being of passengers and crew. One potential avenue presented in the literature involves a redistribution of responsibility towards all agential entities (pilots and technology) within the cockpit system. We discuss the possible pitfalls to this approach, including the reinforcement of pilot skills erosion as well as technology’s own limitations in adaptively dealing with unexpected circumstances. We justify our position by showing how algorithmic (AI) technology’s representational frames mask or severely limit the pilots’ natural reflex to ‘practically cope’ and gain an ‘optimal grip’ with a given context/situation at hand. Here, we present the concept of relevant or meaningful control, which pilots, when allowed to develop their natural brain-body reflexes, gain across gradual mastery of the aircraft. Finally, we propose a socio-technical design approach in which pilots can re-appropriate full human meaningful control of the aircraft, thus allowing them to meet their attributed responsibilities.

Enhancement ofreal‐timegrasp detection by cascaded deep convolutional neural networks

AbstractRobot grasping technology is a hot spot in robotics research. In relatively fixed industrialized scenarios, using robots to perform grabbing tasks is efficient and lasts a long time. However, in an unstructured environment, the items are diverse, the placement posture is random, and multiple objects are stacked and occluded each other, which makes it difficult for the robot to recognize the target when it is grasped and the grasp method is complicated. Therefore, we propose an accurate, real‐time robot grasp detection method based on convolutional neural networks. A cascaded two‐stage convolutional neural network model with course to fine position and attitude was established. The R‐FCN model was used as the extraction of the candidate frame of the picking position for screening and rough angle estimation, and aiming at the insufficient accuracy of the previous methods in pose detection, an Angle‐Net model is proposed to finely estimate the picking angle. Tests on the Cornell dataset and online robot experiment results show that the method can quickly calculate the optimal gripping point and posture for irregular objects with arbitrary poses and different shapes. The accuracy and real‐time performance of the detection have been improved compared to previous methods.