Force Perception Research Articles

Force Perception for Rigid-Soft Finger Without Force Sensors: Theoretical Analysis, and Model Transfer

Force Perception for Rigid-Soft Finger Without Force Sensors: Theoretical Analysis, and Model Transfer

TacSuit: A Wearable Large-Area, Bioinspired Multimodal Tactile Skin for Collaborative Robots

Robots are now working more and more closely with humans outside of traditional fences in industrial scenes. Their real-time tactile interaction perception is crucial to the safety of human–robot collaboration (HRC). In this work, we present a customized, wearable and modular robot skin (TacSuit), which is scalable for large-area surface coverage of robot with easily accessible multi-modal sensors, including pressure, proximity, acceleration and temperature sensors. The TacSuit is co-designed for mechanical structure and data fusion algorithm, consisting of three levels of design: sensor, cell (of multi-modal sensors) and block (of multiple cells). These sensors are stored with custom-designed and 3D printed capsules to achieve the conformity, scalability and easy installation to the arbitrary robot surface. A multi-level event-driven data fusion algorithm enables efficient information processing for large number of tactile sensors. Furthermore, a virtual interaction force fusion method takes both the proximity and force perception information into consideration in order to achieve safety of whole interaction process before and after direct physical contacts. A humanoid robotic platform successfully realizes the TacSuit wear of 159 tactile cells. Validation experiments of obstacle detection demonstrate the effective collision avoidance capability of the TacSuit for safe HRC.

An Angle‐Sensitive Microcolumn‐Based Capacitive Shear Force Sensor for Robot Grasping

AbstractShear force sensors play an indispensable role in tactile perception for robot manipulation tasks. However, recent advancements in shear force sensors have been hindered by issues such as direction sensitivity and integration limitations. This paper proposes a microcolumn array dielectric layer produced using photolithography technology that enables tunability of sensor sensitivity and detection range by adjusting the aspect ratio and interval of the microstructures. Meanwhile, the impact of five constant normal force couplings on the sensitivity of shear force perception is investigated. The structure array with a 1:2 aspect ratio and 600 µm interval demonstrates an ultrahigh sensitivity of 6.189 N−1 and outstanding linearity (R2 = 0.9873) within the range up to 0.1 N. The sensor exhibits low hysteresis and robust stability over 3000 cycles. Additionally, it exhibits remarkable anisotropic direction sensitivity, enabling accurate positioning within a quarter‐circle angle. An intentionally designed orthogonal array is employed to extend the shear angle range up to 360°. Owing to the high performance of the sensor, it is further integrated onto a gripper to facilitate the grasping operation and effectively capture delicate movements. The experimental outcomes highlight that the designed sensor holds promise for applications in robotic applications and electronic skin domains.

A Magnet Splicing Method for Constructing a Three-Dimensional Self-Decoupled Magnetic Tactile Sensor

Tactile sensory organs for three-dimensional (3D) force perception are essential for most living organisms and enable them to perform complex and sophisticated tasks to survive and evolve. Magnetic-based tactile sensors have been developed rapidly in recent years due to the exploitability of 3D force decoupling. Here, a method of magnet splicing is introduced, which can be applied to a magnetic tactile sensor to realize 3D self-decoupling of magnets’ displacements. This method enables the magnets to produce a completely consistent magnetic field distribution as the ideal magnetization model within a certain working range, eliminating the compensation and correction of the 3D magnetic flux density signal. This method carves out a new way for the practical application of 3D decoupling theory, showcasing the great potential in the fields of magnetic sensors and magnetic actuators.

3D Multimodal Sensing and Feedback Finger Case for Immersive Dual‐Way Interaction

AbstractWith the rapid development of virtual reality (VR) technology, artificial intelligence , and the Internet of Things , a new era of immersive interaction with the digital world has emerged. In this context, a novel soft finger case with 3D multi‐modal sensing and feedback functions (3D‐SFC) is presented. The device leverages multiple material properties to create a modulated fingertip haptic feedback for the perception of orientation and force, triboelectric nanogenerator (TENG) sensing with dynamic and static responses and control of movement, and thermal feedback based on resistive heating of TENG electrodes. The integrated TENG tactile sensing unit in the device is capable of recognizing the texture of an object's surface, providing users with a more natural and intuitive way of interacting with digital objects. The spatial consistency of multi‐modal sensing and feedback enhances human‐machine interaction in various fields such as healthcare, manufacturing and assembly, and gaming, etc. The proposed device represents a new intelligent sensing solution for achieving cross‐space sensory interaction, opening up new possibilities for the future of VR and digital interaction.

The influence of elbow and forearm posture on grip force perception in healthy individuals

AbstractThis study aimed to examine the influence of elbow and forearm postures, as well as sex, on the perception of grip force in a sample of individuals without any known health conditions. A total of 21 healthy participants (10 women and 11 men) from college were included and completed a force reproducibility assignment with four elbow and forearm positions (full pronation, supination, and extension, and at 90° of flexion) at three force levels (10%, 30%, and 50% of maximal voluntary isometric contraction [MVIC]). Our results show that participants were more sensitive in detecting variations in their grip force when their elbow was in full supination (14.1 ± 8.5% MVIC, p < .05) and full extension (13.8 ± 10.1% MVIC, p < .01) than when it was at 90° of flexion (19.9 ± 20.1% MVIC). The normalized absolute error exhibited comparable patterns among both male and female participants. Specifically, when the working range of the muscles increased (as indicated by higher maximum voluntary isometric contraction values in males), the accuracy decreased (as reflected by the more significant absolute error in men). Moreover, men exhibited a greater degree of both constant and variable error than women. Recent research indicates that the prevalence of musculoskeletal disorders is higher in women than in males. The results we obtained may contribute to developing strategies to reduce injury risk.

RLNN: A force perception algorithm using reinforcement learning

RLNN: A force perception algorithm using reinforcement learning

Rotational Motion Due to Skin Shear Deformation at Wrist and Elbow.

The hanger reflex is an illusion phenomenon that induces strong force perception and rotational motion, and it occurs in multiple parts of the body. A potential application of this phenomenon is in upper limb rehabilitation for patients with upper-limb paralysis involving arm rotation. However, the only upper limb movements that have been confirmed in this phenomenon are the inward and outward movements of the wrist, which limits the applicable tasks. Therefore, we attempted to apply the hanger reflex to the elbow and use it simultaneously with the wrist. This phenomenon occurs due to shear deformation of the skin, so shear deformation was presented to the skin on the elbow. When shear deformation of the skin was presented to the elbow in the same manner as in previous studies applied to the wrist, movement and force perception of pronation and supination of the elbow were confirmed. The results of an experiment in which the hanger reflex was simultaneously presented to the elbow and wrist showed that each region independently perceived motion and force.

Haptic based fundamentals of laparoscopic surgery simulation for training with objective assessments.

Force is crucial for learning psychomotor skills in laparoscopic tissue manipulation. Fundamental laparoscopic surgery (FLS), on the other hand, only measures time and position accuracy. FLS is a commonly used training program for basic laparoscopic training through part tasks. The FLS is employed in most of the laparoscopic training systems, including box trainers and virtual reality (VR) simulators. However, many laparoscopic VR simulators lack force feedback and measure tissue damage solely through visual feedback based on virtual collisions. Few VR simulators that provide force feedback have subjective force metrics. To provide an objective force assessment for haptic skills training in the VR simulators, we extend the FLS part tasks to haptic-based FLS (HFLS), focusing on controlled force exertion. We interface the simulated HFLS part tasks with a customized bi-manual haptic simulator that offers five degrees of freedom (DOF) for force feedback. The proposed tasks are evaluated through face and content validity among laparoscopic surgeons of varying experience levels. The results show that trainees perform better in HFLS tasks. The average Likert score observed for face and content validity is greater than 4.6 ± 0.3 and 4 ± 0.5 for all the part tasks, which indicates the acceptance of the simulator among subjects for its appearance and functionality. Face and content validations show the need to improve haptic realism, which is also observed in existing simulators. To enhance the accuracy of force rendering, we incorporated a laparoscopic tool force model into the simulation. We study the effectiveness of the model through a psychophysical study that measures just noticeable difference (JND) for the laparoscopic gripping task. The study reveals an insignificant decrease in gripping-force JND. A simple linear model could be sufficient for gripper force feedback, and a non-linear LapTool force model does not affect the force perception for the force range of 0.5-2.5 N. Further study is required to understand the usability of the force model in laparoscopic training at a higher force range. Additionally, the construct validity of HFLS will confirm the applicability of the developed simulator to train surgeons with different levels of experience.

Trajectory Tracking of Variable Centroid Objects Based on Fusion of Vision and Force Perception.

Compared with traditional rigid objects' dynamic throwing and catching by the robot, the in-flight trajectory of nonrigid objects (incredibly variable centroid objects) throwing is more challenging to predict and track. This article proposes a variable centroid trajectory tracking network (VCTTN) with the fusion of vision and force information by introducing force data of throw processing to the vision neural network. The VCTTN-based model-free robot control system is developed to perform highly precise prediction and tracking with a part of the in-flight vision. The flight trajectories dataset of variable centroid objects generated by the robot arm is collected to train VCTTN. The experimental results show that trajectory prediction and tracking with the vision-force VCTTN is superior to the ones with the traditional vision perception and has an excellent tracking performance.

ANALISIS VARIABEL YANG MEMENGARUHI PEMILIHAN PRODUK TABUNGAN BRITAMA PERIODE TAHUN 2023

The purpose of this study was to determine the effect of initial deposit variables, monthly administration fees, labor force perceptions of their work, income, and promotions on prospective customers' decisions in choosing BritAma savings products compared to other savings products at PT. BRI (Persero), Tbk Kepanjen Branch Office and find out what factors have the most dominant influence on the decision. The author uses the Logistic Regression method or Logistics Model Analysis (LOGIT) to analyze qualitative data that reflects the choice between two alternatives. The results show that the initial deposit and income variables have a positive and significant effect, while the monthly administration fee variable has a negative and significant effect on customer decisions. Meanwhile, the labor force's perception of their work and promotions does not have a significant effect on customer decisions. The results of this study can be used as a benchmark for banking, especially PT. BRI (Persero), Tbk to improve its work efficiency in order to gain the trust of the public to save their funds in the bank.

Visualizing Hand Force With Wearable Muscle Sensing for Enhanced Mixed Reality Remote Collaboration.

In this paper, we present a prototype system for sharing a user's hand force in mixed reality (MR) remote collaboration on physical tasks, where hand force is estimated using wearable surface electromyography (sEMG) sensor. In a remote collaboration between a worker and an expert, hand activity plays a crucial role. However, the force exerted by the worker's hand has not been extensively investigated. Our sEMG-based system reliably captures the worker's hand force during physical tasks and conveys this information to the expert through hand force visualization, overlaid on the worker's view or on the worker's avatar. A user study was conducted to evaluate the impact of visualizing a worker's hand force on collaboration, employing three distinct visualization methods across two view modes. Our findings demonstrate that sensing and sharing hand force in MR remote collaboration improves the expert's awareness of the worker's task, significantly enhances the expert's perception of the collaborator's hand force and the weight of the interacting object, and promotes a heightened sense of social presence for the expert. Based on the findings, we provide design implications for future mixed reality remote collaboration systems that incorporate hand force sensing and visualization.

Shear-Pressure Decoupling and Accurate Perception of Shear Directions in Ionic Sensors by Analyzing the Frequency-Dependent Ionic Behavior.

In artificial tactile sensing, to emulate the human sense of touch, independent perception of shear force and pressure is important. Decoupling the pressure and shear force is a challenging task for ensuring stable grasping manipulation for both soft and brittle objects. This study introduces a deformable ion gel-based tactile sensor that is capable of distinguishing pressure from shear force when pressurized shear force is applied in any direction. Recognition of the decoupled forces and precise shear directions is enabled by acquiring tactile data at only two frequencies (20 Hz and 10 kHz) based on the frequency-dependent ion dynamics. This study demonstrates monitoring the changes in pressure, shear force, and shear directions while performing practical robotic actions, such as pouring a water bottle, opening a water bottle cap, and picking up a book and placing it on a shelf.

Retributive Attitudes and Perceptions of Police Use of Excessive Force

Public opinions of police use of force vary widely. Previous studies, however, have framed their examinations around the factors that influence support of police use of force in general, as compared to a focus on excessive force. This study utilized linear regression to examine the relationship between perceptions of police use of excessive force and retributive attitudes. The study employed a sample of 5,527 respondents from the American National Election Studies (ANES) 2020 Time Series Survey. Findings indicated that respondents’ perceptions of the frequency of police use of excessive force depend on their retributive attitudes. The more retributive one’s attitude, the less often they perceived the police to use too much force. Similarly, the more conservative one’s political ideology, the less frequently they perceived police used excessive force. Perceptions of police excessive force also vary across demographics. KEYWORDS: Retributiveness; Death Penalty; Police Use of Force; Police Excessive Force

Flexible instrument with contact-aided structure and force feedback for endoscopic surgery.

Robot-assisted surgery can effectively reduce the difficulty and improve the success rate of the surgeries. However, currently available flexible instruments have several limitations, such as large size, few degrees of freedom, and lack of contact force perception. This study proposes a master-slave flexible instrument capable of force feedback. The instrument has a maximum outer diameter of 3mm and an overall length of 1200mm. With the internal working channel unoccupied, a three-dimensional force sensing unit is designed based on the neural network. The corresponding master-slave control method with proportional force feedback was also designed to effectively control the instrument. To verify the effectiveness of the system, in vitro and in vivo experiments were conducted. The corresponding tasks were successfully completed. The animal trial conducted in the digestive tract of a live swine proved that the system has the potential for clinical use.

A Back-Drivable Rotational Force Actuator for Adaptive Grasping

In this paper, a back-drivable and miniature rotary series elastic actuator (RSEA) is proposed for robotic adaptive grasping. A compact arc grooves design has been proposed to effectively reduce the dimension of the RSEA system. The elastic elements could be reliably embedded in the arc grooves without any additional installation structures. The whole RSEA system is characterized as compact, miniature, and modular. The actuating force is controlled via a PI controller by tracking the deformation trajectory of the elastic elements. An underactuated finger mechanism has been adopted to investigate the effectiveness of the RSEA in robotic adaptive grasping. Results reveal that the underactuated finger mechanism could achieve adaptive grasping via the RSEA in a back-drive approach without the requirement of a fingertip force sensor. The RSEA could also exhibit an actuating compliance and a self-sensing characteristic. The actuating compliance characteristic helps in in guaranteeing the safety of human–robot interaction. The RSEA could estimate the external disturbance due to its self-sensing characteristic, which has the potential to replace the fingertip force sensor in grasping force perception applications.

A human‐robot collaboration method for uncertain surface scanning

AbstractRobots are increasingly expected to replace humans in many repetitive and high‐precision tasks, of which surface scanning is a typical example. However, it is usually difficult for a robot to independently deal with a surface scanning task with uncertainties in, for example the irregular surface shapes and surface properties. Moreover, it usually requires surface modelling with additional sensors, which might be time‐consuming and costly. A human‐robot collaboration‐based approach that allows a human user and a robot to assist each other in scanning uncertain surfaces with uniform properties, such as scanning human skin in ultrasound examination is proposed. In this approach, teleoperation is used to obtain the operator's intent while allowing the operator to operate remotely. After external force perception and friction estimation, the orientation of the robot end‐effector can be autonomously adjusted to keep as perpendicular to the surface as possible. Force control enables the robotic manipulator to maintain a constant contact force with the surface. And hybrid force/motion control ensures that force, position, and pose can be regulated without interfering with each other while reducing the operator's workload. The proposed method is validated using the Elite robot to perform a mock B‐ultrasound scanning experiment.

BiTac: A Soft Vision-Based Tactile Sensor With Bidirectional Force Perception for Robots

Although various designs have been reported in the literature for vision-based tactile sensors, a few of them can detect pressing forces. These designs are often addressed with learning-based approaches that critically rely on training and require large amounts of training data. This study presents a novel visuotactile sensing technology for the development of large-scale vision-based tactile sensors named BiTac, which can accurately reconstruct its 3-D surface shape in real-time and is capable of detecting the bi-directional distribution of normal forces applied to its soft sensing surface. The sensor skin was made of soft and elastic materials composed of an array of markers which are tracked efficiently by a compact stereo camera, whose parameters could be calibrated automatically. Notably, the complexity of mapping the displacement fields calculated from the images to the normal force distribution is resolved by the finite element method, which would be a generalized modeling technique for soft materials. This article comprehensively covers the design, fabrication, theoretical modeling, calibration, and experiments. The hardware capability and tactile perception were assessed quantitatively and qualitatively through real interactions with various objects. With a simple structure and analytical approach, the BiTac sensor can be easily customized and manufactured for different parts of robots, making it a potential design for mass production.

A novel knowledge-driven flexible human–robot hybrid disassembly line and its key technologies for electric vehicle batteries

Based on the unique problems and challenges in the disassembly scenario of waste electric vehicle batteries (EVBs), we propose a knowledge-driven flexible human–robot hybrid disassembly line. The disassembly line can not only split the EVB disassembling tasks layer by layer to the primitive-level subtasks based on knowledge but also intelligently generate the optimal disassembling primitive sequence to complete the disassembling task. To further elaborate on the key technologies of the above-mentioned disassembly line, we focus on the implementation of the high-accuracy screw disassembly and disassembly planning system based on NeuroSymbolic. Implementation of the high-accuracy screw disassembly is realized by a new design of the disassembly actuator, high-accuracy screw position and pose estimation based on visual perception, and robust insertion based on force perception. The disassembly planning system is constructed by defining disassembly primitives and introducing neural predicates which can take the sensor data as input and output the symbolic states. Experiments show that our system can effectively solve the screw disassembling task in complex disassembly scenarios.

Mutual Influences in Orthodox Missions among the Nanai People in the Russian Far East

Abstract Among the Nanai in the Russian Far-East, the Russian Orthodox Church has been conducting missions in two villages since 2011. In this article, I analyze the usage of Nanai iconography in the printed Gospel of Luke and of oral myths to tell the Nanai version of the Christian message. A specific Nanai Christianity is thus perceptible, rooted within shamanism, that is, the emic perception of powerful forces at play in the world, with whom humans are in constant negotiations. Based on ethnographic fieldwork conducted in the Amur region, this analysis will highlight the Indigenous agency in the appropriation of the Christian doctrine.