54 accepted papers
This paper presents a novel design concept of a pair of soft gripper hands that can establish a secure connection between them for bearing a large load with a low air pressure. The design was inspired by dovetail joints in carpentry that enable a tight, strong connection between two pieces of wood.
As over 11,000 people turn 65 each day in the U.S., our country, like many others, is facing growing challenges in caring for elderly persons, further exacerbated by a major shortfall of care workers. To address this, we introduce an elder-care robot (E-BAR) capable of lifting a human body, assistin
Pneumatic soft everting robotic structures have the potential to facilitate human transfer tasks due to their ability to grow underneath humans without sliding friction and their utility as a flexible sling when deflated. Tubular structures naturally yield circular cross-sections when inflated, wher
This letter presents a computational method, called Bootstrapped Koopman Direct Encoding (B-KDE) that allows us to approximate the Koopman operator with high accuracy by combining Koopman Direct Encoding (KDE) with a deep neural network. Deep learning has been applied to the Koopman operator method
Grab bars are widely used to provide elderly persons with support for daily activities, but their utility is limited by room geometry, cost of installation, and potential obstruction of other movements. We address these challenges through a mobile robot that can place a handlebar at any point in spa
A global modeling methodology based on Koopman operator theory for the dynamics of rigid bodies that make and break contact is presented. Traditionally, robotic systems that contact with their environment are represented as a system comprised of multiple dynamic equations that are switched depending…
It is often challenging to pick suitable data features for learning problems. Sometimes certain regions of the data are harder to learn because they are not well characterized by the selected data features. The challenge is amplified when resources for sensing and computation are limited and time-cr
This paper proposes the utilization of Supernumerary Robotic Limbs (SuperLimbs) for augmenting astronauts during an Extra-Vehicular Activity (EVA) in a partial-gravity environment. We investigate the effectiveness of SuperLimbs in assisting astronauts to their feet following a fall. Based on prelimi…
The navigational abilities of tip-everting soft growing robots, known as vine robots, are compromised when tip-mount devices are added to enable carrying of payloads. We present a new method for securing a vine robot to objects or its environment that exploits the unique eversion-based growth mechan…
Age-related loss of mobility and an increased risk of falling remain major obstacles for older adults to live independently. Many elderly people lack the coordination and strength necessary to perform activities of daily living, such as getting out of bed or stepping into a bathtub. A traditional so…
Safely harnessing and lifting humans for transfer is a challenging unsolved problem for current robots because of the high forces and gentle interaction necessary to do so. Straps, however, are highly beneficial for manually performing this task primarily because of their simultaneously high tensile
Although telepresence assistive robots have made significant progress, they still lack the sense of realism and physical presence of the remote operator. This results in a lack of trust and adoption of such robots. In this paper, we introduce an Avatar Robot System which is a mixed real/virtual robo…
This letter presents a data-driven method for constructing a Koopman linear model based on the Direct Encoding (DE) formula. The prevailing methods, Dynamic Mode Decomposition (DMD) and its extensions are based on least squares estimates that can be shown to be biased towards data that are densely p
This paper discusses the incorporation of a pair of Supernumerary Robotic Limbs (SuperLimbs) onto the next generation of NASA space suits. The wearable robots attached to the space suit assist an astronaut in performing Extra-Vehicular Activities (EVAs). The SuperLimbs grab handrails fixed to the ou…
A lifting-linearization method based on the Koopman operator and Dual Faceted Linearization is applied to the control of a robotic excavator. In excavation, a bucket interacts with the surrounding soil in a highly nonlinear and complex manner. Here, we propose to represent the nonlinear bucket-soil
While manufacturing heavy and large machinery, the insertion of crane-hung heavy parts into horizontal holes is often required. This paper presents a method outlining the horizontal insertion of a ring onto a shaft using a gantry crane with a single cable attachment. We exploit the underactuated nat
Model Predictive Control (MPC) of nonlinear hybrid systems using lifting linearization underpinned by Koopman Operator is presented. Unlike standard linearization, which is valid only locally, lifting linearization provides a global linear representation of a nonlinear system in a lifted space. This
In providing physical assistance to elderly people, ensuring cooperative behavior from the elderly persons is a critical requirement. In sit-to-stand assistance, for example, an older adult must lean forward, so that the body mass can shift towards the feet before a caregiver starts lifting the body…
Overhead cranes have been used extensively in heavy industry for transporting heavy objects across a factory floor. This work aims to make such cranes more dexterous and capable of performing precision assembly tasks by suspending an object with tension-controlled cables. New control strategies are
A pair of Supernumerary Robotic Limbs (Super-Limbs) can brace the wearer’s upper body while they work at floor level, and support them during crawling. The SuperLimbs’ motion is synchronized with the operator to mimic natural human crawling. This synchronization relies on experimental data from the…
Optimization of gear ratios for dual-motor actuators is presented for the development of a walker-type assist robot. The robot is reconfigurable to provide an elderly user with multiple physical support functions; one is to assist sitto-stand transitions and the other is to serve as a walker to aid…
This letter presents a new type of wearable robot, called the Hybrid SuperLimb, which integrates voluntary human movements and the autonomous reactive control of a robotic limb. Some degrees of freedom (DOF) of the SuperLimb are powered by human body movements and are controlled voluntarily and dire
Effective and causal observable functions for low-order lifting linearization of nonlinear controlled systems are learned from data by using neural networks. While Koopman operator theory allows us to represent a nonlinear system as a linear system in an infinite-dimensional space of observables, ex
Overhead manipulation tasks often require collaborations between two operators, which becomes challenging in confined spaces such as in a compartment. Supernumerary Robotic Limb (SuperLimb), as a promising wearable robotic solution, can provide assistance in terms of broader workspace, wider manipul
In heavy industries, large, heavy objects must be tumbled to access features on their bottoms and sides for assembly and maintenance. Traditional manual operations using a single-cable crane are high-risk, and difficult for less experienced workers. Automating the tumbling process is made challengin
We develop a data-driven, statistical control method for autonomous excavators. Interactions between soil and an excavator bucket are highly complex and nonlinear, making traditional physical modeling difficult to use for real-time control. Here, we propose a data-driven method, exploiting data obta
In large-scale open-pit mining and construction works, excavators must deal with large rocks mixed with gravel and granular soil. Capturing and moving large rocks with the bucket of an excavator requires a high level of skill that only experienced human operators possess. In an attempt to develop au
An extendable robot inspired by origami is designed, analyzed, and tested. Its deployable origami structure has a large extension ratio, allowing the robot to extend the body length multiple times. The new robot, however, differs from the existing origami structure in two aspects. One is that the ro
This paper presents a wheeled wall-climbing robot with a shape-adaptive magnetic adhesion mechanism for large steel structures. To travel up and down various curved ferromagnetic surfaces, we developed a 2 DOF rotational magnetic adhesion mechanism installed on each wheel that can change the orienta…
A human has over 200 muscles in the body, creating a high degree of flexibility and redundancy in movement. This paper exploits this high degree of redundancy for the actuation and control of Supernumerary Robotic Limbs (SuperLimbs), which are attached to a human body. SuperLimbs containing many act
The Extra Robotic Legs (XRL) system is a robotic augmentation worn by a human operator consisting of two articulated robot legs that walk with the operator and help bear a heavy backpack payload. It is desirable for the Human-XRL quadruped system to walk with the rear legs lead the front by 25% of t…
A new approach to precision mating of heavy objects suspended from overhead cranes is presented. We have found through experiments that heavy shafts suspended with multiple cables at specific positions and orientations can be inserted into a chamfered hole despite a small clearance. This will allow
Inspection and maintenance of equipment inside buildings, such as exit signs, bared pipelines, air vents, and fire alarms often requires a robot to reach high, hidden, or confined areas that are difficult for humans to access. Even though these tasks are easy and repeatable, they are still not autom…
A new approach to autonomous excavator control that allows the machine to adapt to unknown soil properties is presented. Unlike traditional force control or trajectory control, the new method uses the product of force and velocity, namely, the power transmitted from the excavator to the soil, as a s
During immune surveillance, cytotoxic T lymphocytes (CTL) can selectively identify and destroy tumor cells by recognizing tumor-specific peptides (neoantigens), bound to major histocompatibility complex molecules (pMHC) arrayed on cancer cell surfaces. CTL use the same machinery to destroy virally i
Aircraft manufacturing, construction, and agricultural production often involve workers maintaining uncomfortable postures, such as stooping and kneeling, for extended periods of time. We present a wearable robot, called MantisBot Alpha, that consists of two expandable robotic arms that brace a work…
A novel design concept of expandable robotic arm inspired by plant growth is presented. The robot can construct its own structure by converting a type of fluidized material into a rigid structure at its growing point. The robot can extend its structure in multiple directions, and move through a wind…
A new approach to the human-robot shared control of the extra robotic legs (XRL) wearable augmentation system is presented. The XRL system consists of two extra legs that bear the entirety of its backpack payload, as well as some of the human operator's weight. The XRL system must support its own ba
When a human performs a task with the assistance of wearable extra limbs, the human movement for performing the task may inadvertently disturb the position and orientation of the robot base, making it difficult for the robot to properly carry out its objective. Therefore, unlike self-standing robots…
We present the design of a new robotic human augmentation system that will assist the operator in carrying a heavy payload, reaching and maintaining difficult postures, and ultimately better performing their job. The Extra Robotic Legs (XRL) system is worn by the operator and consists of two articul…
Final assembly, inspection, and maintenance of aircrafts, automobiles, and industrial equipment often requires a robot to reach confined areas that are difficult to access. While a robot can move freely in open space, the last one foot to a target site in a manufacturing environment is typically clu
Fulfillment centers located in densely populated urban areas are an ever-growing need for leading online consumer websites. These urban fulfillment centers have limited land mass and must have innovative solutions to transport goods within the available vertical space. This work presents a Multi-Tra…
A new type of parallel robot mechanism with an extendable structure is presented, and its kinematic properties and design parameters are analyzed. The triple scissor extender (TSE) is a six-degree-of-freedom robotic mechanism for reaching high ceilings and positioning an end effector. Three scissor
Most of the wearable robots today assist their users by acting in parallel or in series to their natural limbs. We propose a different approach to wearable robotics, consisting of devices that provide users with additional, independent robotic limbs. We present a wearable robot prototype that can ac…
This paper presents a robotic system where the gear-ratio of an actuator is dynamically changed to either leverage or attenuate the natural load dynamics. Based on this principle, lightweight robotic systems can be made fast and strong; exploiting the natural load dynamics for moving at higher speed
Design and control of a novel extra robotic arm attached to the shoulder of a worker for performing tasks in the overhead area are presented. The wearable robot, called Supernumerary Robotic Limbs (SRL), can lift an object and hold it while the wearer is securing the object using a tool with both ha…
A novel wearable robotic device is developed to support the wearer when performing bi-manual tasks near the ground. The device is worn around the upper torso and has two Supernumerary Robotic Limbs (SRLs) that reach the ground when the wearer assumes a crawling-like position, such that neither of th…
This paper addresses the closed-loop control of an actuator with both a continuous input variable (motor torque) and a discrete input variable (mode selection). In many applications, robots have to bear large loads while moving slowly and also have to move quickly through the air with almost no load
We present a novel 6 DOF robotic mechanism for reaching high ceilings and positioning an end-effector. The end-effector is supported with three scissor mechanisms that extend towards the ceiling with 6 independent linear actuators moving the base ends of the individual scissors. The top point of eac
In many applications, robots have to bear large loads while moving slowly and also have to move quickly through the air with almost no load. This leads to conflicting requirements for their actuators. Multiple gear ratios, like in a powertrain, address this issue by allowing an effective use of powe…
Cell migration is a fundamental process for the development and maintenance of all multicellular organisms. Accurate cell tracking may lead to better interpretations of long-term cell behaviours. This paper describes an automated system to track multiple cells from experimental phase contrast images…
This paper presents a novel approach to balance assistance and joint load reduction for human bipedal walking. We introduce a new type of wearable robot, called Supernumerary Robotic Limbs (SRL), that provides two additional legs for augmenting stability and reducing the loads on human leg joints. U…
Similar to combustion engines comprising multiple cylinders engaged with a crankshaft, multiple piezoelectric stack actuators (PSA) engaged with a common output rod can produce smooth, long stroke motion with desired properties. In particular, when equally spaced multiple units are arranged to push…
Functionality of a human hand can be augmented with extra robotic fingers attached to the forearm. These wearable extra fingers can work together with the human fingers and perform tasks that are usually difficult for a single hand. Such technology may benefit amputees and surviving stroke patients…