Rui Liu

Kent State University | KSU

Motivation: As quality assurance is of strong concern in advanced surgeries, intelligent surgical systems are expected to have knowledge such as the knowledge of the surgical workflow model (SWM) to support their intuitive cooperation with surgeons. For generating a robust and reliable SWM, a large amount of training data is required. However, tra...

Human-centered situation, which describes the surrounding world of a person, indicates his undergoing activities. Understanding of human-centered situations helps an assistive robot with its decision making. Existing methods, such as learning from human demonstration, are economically expensive, time-consuming, and have limited scalability. To addr...

Intelligent robotic assistance requires a robot to accurately understand human behavior. Many researchers have explored human-object interactions to decode behavior-related information. However, current methods only model probabilistic correlations between objects and activities. Their applications are usually limited to fixed environments and fixe...

With the large-scale application and development of lithium-ion batteries, the extraction of lithium resources from salt lake brine has gradually become a global focus. Lithium titanium oxides (LTO)-type lithium ion-sieve (LIS) has attracted much attention due to its stable structure, high adsorption capacity, excellent recycling capacity, and envi...

Over recent years, numerous studies have been concerned with recovering value-added products from sludge. Various methods have been used to prepare it as an adsorbent. Herein, a comprehensive and critical analysis of sources, pretreatments, activations, applications and environmental leaching risks of sludge-based activated carbon (SBAC) has been c...

A novel polydopamine/reduced graphene oxide/MOF-5 (PDA/RGO/MOF-5) composite membrane with high flux, outstanding dye separation performance and anti-fouling ability was prepared by synthesizing the polydopamine-modified GO/MOF-5 composite material and aggregating it on a commercial cellulose acetate (CA) membrane substrate through the vacuum filtra...

In order to remove bisphenol A (BPA) in wastewater, this paper reported an amino-functionalized oily sludge-derived carbon (GP-H-OSC) obtained by grafting amino groups using oily sludge as a precursor, which could quickly adsorb BPA in the wastewater. The adsorption results showed that the grafting modification method was more likely to form effect...

As one of natural nano-clay material, sepiolite is easy to modify to obtain low surface energy, which has great potential in the field of superhydrophobicity application. A novel superhydrophobic micro nanofibers (CSEP / OTS) were prepared by grafting long alkyl chains onto organic activated sepiolite fibers (CSEP) by using octadecyltrichlorosilane...

Big challenges are usually occurring in non-rigid 3D shape retrieval, for the shapes undergoing arbitrarily non-affine transformations. In this work, a novel design of feature learning approach is proposed for non-rigid 3D shape retrieval, dubbed Structured Sparsity Regularized Multi-Modality Method (SSR-MM). The shape signatures which capture the...

Human multi-robot system (MRS) collaboration is demonstrating potentials in wide application scenarios due to the integration of human cognitive skills and a robot team's powerful capability introduced by its multi-member structure. However, due to limited human cognitive capability, a human cannot simultaneously monitor multiple robots and identif...

To control part quality, it is critical to analyze pore generation mechanisms, laying theoretical foundation for future porosity control. Current porosity analysis models use machine setting parameters, such as laser angle and part pose. However, these setting-based models are machine dependent, hence they often do not transfer to analysis of poros...

In human-robot collaboration (HRC), human trust in the robot is the human expectation that a robot executes tasks with desired performance. A higher-level trust increases the willingness of a human operator to assign tasks, share plans, and reduce the interruption during robot executions, thereby facilitating human-robot integration both physically...

To control part quality, it is critical to analyze pore generation mechanisms, laying theoretical foundation for future porosity control. Current porosity analysis models use machine setting parameters, such as laser angle and part pose. However, these setting-based models are machine dependent, hence they often do not transfer to analysis of poros...

A human-swarm cooperative system, which mixes multiple robots and a human supervisor to form a heterogeneous team, is widely used for emergent scenarios such as criminal tracking in social security and victim assistance in a natural disaster. These emergent scenarios require a cooperative team to quickly terminate the current task and transit the s...

Emergency happens in human-UAV cooperation, such as criminal activity tracking and urgent needs for ground assistance. Emergency response usually has high requirements on the motion control of the multi-UAV system, by maintaining both the team performance and team behaviors. However When a UAV swarm executes tasks in a real-world environment, becau...

Due to world dynamics and hardware uncertainty, robots inevitably fail in task executions, leading to undesired or even dangerous executions. To avoid failures for improved robot performance, it is critical to identify and correct robot abnormal executions in an early stage. However, limited by reasoning capability and knowledge level, it is challe...

Mixed Cooperation and competition are the actual scenarios of deploying multi-robot systems, such as the multi-UAV/UGV teaming for tracking criminal vehicles and protecting important individuals. Types and the total number of robot are all important factors that influence mixed cooperation quality. In various real-world environments, such as open s...

The deployment of robot swarms is influenced by real-world factors, such as motor issues, sensor failure, and wind disturbances. These factors cause the appearance of faulty robots. In a decentralized swarm, sharing incorrect information from faulty robots will lead to undesired swarm behaviors, such as swarm disconnection and incorrect heading dir...

It is critical for advanced manufacturing machines to autonomously execute a task by following an end-user's natural language (NL) instructions. However, NL instructions are usually ambiguous and abstract so that the machines may misunderstand and incorrectly execute the task. To address this NL-based human-machine communication problem and enable...

The stability and trajectory control of a quadrotor carrying a suspended load with a fixed known mass has been extensively studied in recent years. However, the load mass is not always known beforehand in practical applications. This mass uncertainty brings uncertain disturbances to the quadrotor system, causing existing controllers to have a worse...

To provide timely and appropriate assistance, robots must have the capability of proactively understanding a user’s personal needs, so called human intention inference. In human-human interaction, humans have a natural and implicit way to infer others’ intentions by selecting correlated context features and interpreting these features based on thei...

To provide the elderly with appropriate and timely caregiving in activities of daily life (ADL), it is desired for robots to have the capability of intention awareness (IA). Different from existing context-specific intention awareness (CSIA) approaches which are based on a limited and passive knowledge database, our approach, named 'WebIA', adopts...

For an assistive robot, accurately understanding the user's intention with minimal user involvement is critical in human-robot interaction. Especially for the elderly in their Activities of Daily Living (ADL), implicit intention recognition using subtle cues could provide them great convenience as well as improving quality of life. Usually user int...

To solve the actuator mutual interference problem in the multi-channel active vibration control, control focus was adjusted and the coupling way of control channels was revised. By the revised way, positive feedbacks between the actuators have been suppressed effectively and control purpose has been achieved fast and stably. The revised way is base...