33 accepted papers
We present a hybrid robotic skin that combines electrical impedance tomography (EIT) with pneumatic tactile sensing to improve force reconstruction capability. The developed robotic skin is fabricated entirely by 3D printing and spray coating, making it affordable and easy to build. A Tikhonov-regul…
Vision-based tactile sensors are highly promising for enabling robots to perform dexterous, contact-rich manipulation tasks by providing high-resolution tactile data. Recent studies have attempted to implement shape reconstruction and force estimation capabilities for sensors with omnidirectional se…
The Koopman operator framework has shown promising results in enabling the analysis of nonlinear dynamics into an infinite-dimensional linear representation. Koopman direct encoding (KDE) is a model-based approach that utilizes inner products and compositions in a Hilbert space to compute the Koopma
When manipulating an object, a robot must recognize not only the parts it directly grasps but also the surfaces in contact with the environment, which we refer to as extrinsic contact surfaces. These surfaces directly affect how the object interacts with its environment, and accurate surface estimat
Electrical Resistance Tomography (ERT) has emerged as a promising technology for large-area robotic skin due to its ability to reconstruct pressure distribution over extensive regions using a few sparsely distributed electrodes. Despite ERT's potential to reconstruct the external forces applied on 3
Hand gesture recognition (HGR) is crucial in developing advanced prosthetics, neurorobotics, and human-robot interaction (HRI). Surface electromyography (sEMG) and high-density sEMG (HD-sEMG) have gained attention for their ability to capture the muscle activity underlying hand gestures. Although ma
This paper presents a wearable soft sensing band with stretchable sensors to monitorcle activity by estimating muscle volume changes. Unlike conventional surface electromyography (sEMG) sensing techniques, which require excessive pressure or adhesive electrodes, the proposed sensing method allows mu
Dexterous robotic grasping gains great benefits from tactile sensation, but delicate object exploration by tactile information is challenged by difficulty in rich and efficient data production. In this letter, we propose a tactile-based in-hand object perception approach, empowered by a sim-to-real
This study proposes a bidirectional double-spring pneumatic artificial muscle (PAM) with inductive self-sensing for wearable robotic devices. The actuator structure, composed of commercially available latex and springs, enables a low-cost and consistent manufacturing process. Springs, which serve as
Data-driven methods have been successfully applied to images from vision-based tactile sensors to fulfill various manipulation tasks. Nevertheless, these methods remain inefficient because of the lack of methods for simulating the sensors. Relevant research on simulating vision-based tactile sensors
Human employs different touch patterns to convey diverse social messages; for example, a stroke is an encouragement, whereas a hit is an offense. Various tactile sensors have been developed to grant an intuitive physical interaction with a robotic system, yet many encountered limitations in achievin…
The surface electromyography(sEMG) sensor is widely used as a human-machine interface in wearable systems. Although numerous studies have applied compact sEMG systems to wearable devices, these are inconvenient and not suitable for long-term use. Herein, we introduce a 2.5D laser cutting method to a
Robots performing close physical interaction with humans would require a continuously variable transmission to operate in the region around the peak efficiency or peak power of the driving system. Conventional continuously variable transmission (CVT) has shown advantages in energy-efficient driving…
Vision-based tactile sensors provide diverse information of external tactile stimuli on the skin of sensors using both marker and reflective membrane images. However, when markers and reflective membranes are used concurrently, conventional opaque markers inevitably disturb the camera’s view of the
A human can socially interact in a non-verbal manner by understanding the intention behind a tactile stimulus. Patting on one’s back is one of tactile communications, which is considered as a sign of encouragement in most cultures. The majority of such tactile communication is carried out by a dynam…
Hydrostatic transmission has shown promising results for enabling the manipulator to achieve low effective inertia, high stiffness, and high torque density. However, the incompressibility of fluid causes the lack of compliance, so that it could not provide intrinsic safety. Thus, it would be advanta…
The tactile and proprioceptive sensation increases human manipulability, and soft tissue compliance stabilizes the grasping function. However, it is challenging to transpose this system to the small confined space of soft robotic fingers due to the material properties and complex wiring entailed. Fu…
A pneumatic artificial muscle (PAM) has been widely adopted in a wide range of wearable applications, but the bulkiness and the slow response of the actuator have remained a challenge. In this work, we developed a flat fabric PAM (ffPAM), achieving high compactness, rapid response, and low hysteresi
Compliance in robot actuation provides a solution to perform safe physical human-robot interaction. Conventional compliant actuators (variable stiffness actuators, series elastic actuators) used more than two motors or closed-loop controller to modulate both stiffness and equilibrium position indepe…
Electrical resistance tomography (ERT) has previously been utilized to develop a large-scale tactile sensor because this approach enables the estimation of the conductivity distribution among the electrodes based on a known physical model. Such a sensor made with a stretchable material can conform t…
To reduce the possibility of lower back pain (LBP), which is the most frequent injury in manual labor, several back support exoskeletons have been developed and implemented for lifting motion assistance. Although pneumatic power transmission is attractive due to its inherent compliance and backdriva
In recent years, inflatable actuators have been widely used in wearable suits to assist humans who need help in moving their joints. Despite their lightweight and simple structure, they have long inflation and deflation times, which make their quick use difficult. To resolve this issue, we propose a
Pneumatic transmission has several advantages in developing powered ankle foot orthosis (AFO) systems, such as the flexibility in placing pneumatic components for mass distribution and providing high back-drivability via simple valve control. However, pneumatic systems are generally tethered to larg…
A data-driven approach has recently been investigated for identifying human joint angles by means of soft strain sensors because of the corresponding modeling difficulty. However, this approach commonly incurs a high computational burden due to the voluminous amount of data required and the time-ser
Humans perform grasping by breaking down the task into a series of action phases, where the transitions between the action phases are based on the comparison between the predicted tactile events and the actual tactile events. The dependency on tactile sensation in grasping allows humans to grasp obj…
Recently, a whole-body tactile sensing have emerged in robotics for safe human-robot interaction. A key issue in the whole-body tactile sensing is ensuring large-area manufacturability and high durability. To fulfill these requirements, a reconstruction method called electrical impedance tomography…
An echinoderm can actively modulate the structural stiffness of its body wall by as much as 10 times, using the material and structural features that make up its body, including calcite ossicles, connective tissue and interossicular muscle. This capacity for variable stiffness makes it possible to a…
Robots operating in unstructured environments would benefit from soft whole-body tactile sensors, but implementing such systems typically requires complex electrical wiring to a large number of sensing elements. The reconstruction method called electrical resistance tomography (ERT) has shown promis…
Despite the rapid advances in soft robotic actuation technologies, the main energy source that powers most wearable systems remains the conventional tethered stationary air compressor that greatly limits these systems' applicability. Several portable pneumatic energy sources have been introduced; ho
The closer distance between robots and human partners in the same space makes compliant robots essential in these days. While torque sensor based impedance control scheme suffers from insufficient bandwidth, musculoskeletal systems can achieve similar ability with smaller resources by using mechanic…
Inspired from Hogan's myoelectric processor in 1980, this study presents a stochastic sEMG processing method to estimate the muscle activation level for manipulator control. Hogan's previous study showed the feasibility to estimate the muscle activation level with multi-channel sEMG under static for…
The stabilization of man-made artificial systems has been achieved by sensor based state feedback control with high computational bandwidth and high stiffness structures. In contrast, many biological systems have been achieved similar or superior stable behavior with low speed signal transmission vi…
This paper presents a printable skin adhesive stretch sensor to estimate rotation angles of multi-axis joint for biomedical engineering applications, such as gait analysis, gesture recognition, and motion monitoring. Silicone rubber mixed with multiwall carbon nanotube composites were fabricated to