Lina Hao

• Northeastern University

Pneumatic artificial muscles (PAMs), recognized as typical smart material actuators, have perennially presented a formidable challenge in the realm of precise mechanical modeling due to the hyperelasticity and nonlinearity. In order to construct the mechanical model of the PAM, we propose a constitutive artificial neural network-based mechanical mo...

In this study, a fuzzy adaptive impedance control method integrating the backstepping control for the PAM elbow exoskeleton was developed to facilitate robot-assisted rehabilitation tasks. The proposed method uses fuzzy logic to adjust impedance parameters, thereby optimizing user adaptability and reducing interactive torque, which are major limita...

Effective adaptive grasping capability is regarded as crucial for climbing robots. However, many dry adhesion legged climbing robots are primarily focused on mobility and load capacity to perform various climbing tasks, often overlooking their operational grasping abilities. Furthermore, flexible grippers designed for adaptive grasping are typicall...

Reinforcement learning algorithms usually focus on a specific task, which often performs well only in the training environment. When the task changes, its performance drops significantly, with the algorithm lacking the ability to adapt to new environments and tasks. For the position control of a pneumatic continuum manipulator (PCM), there is a hig...

The optimum performance position control of pneumatic artificial muscles (PAM) is restricted by their in-built hysteresis and nonlinearity. The hysteresis is usually depicted by a phenomenological model, while the model mentioned above always only describes the hysteresis phenomenon under certain conditions. Thus, the universality of the compensato...

The pneumatic artificial muscle (PAM) is widely applied in various scenarios due to their compliance and highefficiency characteristics. However, the online modeling method which can accommodate online data remains an unresolved issue when data cannot be obtained off-line. This paper proposes an online incremental modeling method based on the physi...

In the process of trajectory optimization for robot manipulator, the path that is generated may deviate from the intended path because of the adjustment of trajectory parameters, if there is limitation of end-effector path in Cartesian space for specific tasks, this phenomenon is dangerous. This paper proposes a methodology that is based on the Par...

This paper proposes an unmanned combat decision-making algorithm based on PPO and expert systems. The experimental results show that the algorithm has good decision-making ability. A strategy optimization method based on self-encoding neural network is proposed, which greatly improves the effective decision-making rate of the original algorithm. In...

Exoskeletal robots are of critical importance in the domain of mechanical boosting. The pneumatic artificial muscle (PAM) is commonly used as a flexible actuator in exoskeletal robots designed for upper limbs due to its high power-to-weight ratio, conformability, and safety. This study establishes a new model based on the existing model to improve...

Payload capacity is a crucial factor for climbing robots, as it directly affects their ability to carry and transport heavy loads during various climbing tasks. However, many dry adhesion-based legged robots prioritize foot design from a bionic perspective to accomplish various climbing tasks while overlooking payload capacity. To address this issu...

Shape memory alloy (SMA), a kind of smart material, can be used as an actuator in many fields; however, its strong nonlinearity and parameter uncertainty hinders its application in high-tracking accuracy tasks. This paper addresses the tracking control problem of the SMA actuated swing platform suffering from completely unknown nonlinear model info...

This paper presents a novel optimization process for the proposed general asymmetric S-curve (AS-curve) profile to achieve fast movement and low residual vibration. The general AS-curve profile, which is the superset of traditional symmetric S-curve and prior asymmetric S-curve profiles, enables independent manipulation of accelerations and jerks a...

Reinforcement learning(RL) is attempted to be applied to the control of continuum robots. Because of the inefficiency and high cost of collecting samples in the real world, the control strategy is usually learned in simulation. However, due to the gap between the simulation and the real world, the performance of the strategy learned in the simulati...

The hybrid game system suffers from the constantly time-varying environment and the heterogeneous behaviors of decision-making subjects (players) when the hybrid situation emerges, bringing significant challenges to situation representation and strategic reasoning. With the help of the powerful modeling ability of hybrid systems for situation repre...

This article addresses the data-driven performance-prescribed continuous-time optimal tracking control problem for the shape memory alloy (SMA) actuated systems with completely unknown model knowledge. Firstly, the error constraint problem is transformed into the unconstrained error tracking problem by the prescribed performance control (PPC) metho...

This article focuses on the continuous-time optimal tracking control problem of a shape memory alloy (SMA) actuated manipulator subject to prescribed error constraints and completely unknown nonlinear dynamics. Firstly, prespecified error constraints imposed by the prescribed performance function (PPF) are transformed into an equivalent unconstrain...

This paper presents an effective trajectory generation algorithm to shorten and smooth the jerky paths obtained from the sampling-based planners in cluttered environments. We utilize the cubic smoothing B-spline curves to represent the final trajectories that are collision-free, strict C2 continuity and respect velocity and acceleration constraints...

In this paper, a novel data-driven model-free adaptive fractional-order sliding mode controller with prescribed performance is proposed for the shape memory alloy (SMA) actuator. Due to the strong asymmetric saturated hysteresis nonlinear characteristics of the SMA actuators, it is not easy to establish an accurate model and develop an effective co...

Compared with the traditional rigid mechanism, the flexible mechanism has more advantages, which play an important role in critical situations such as microsurgery, IC (integrated circuit) fabrication/detection, and some precision operating environment. Especially, there is an increasing need for 3-DOF (degrees-of-freedom) compliant translational m...

This paper focuses on the data-driven adaptive control problem of the shape memory alloy (SMA) actuators subject to uncertainties, input saturation and prescribed performance. Firstly, the uncertainties estimation method, anti-windup technology, and prescribed performance function are introduced to deal with uncertain nonlinearity, input constraint...

In this study, a model-free adaptive sliding mode control method was developed in combination with the prescribed performance method. On this basis, this study attempted to fulfill the joint position tracking trajectory task for the one-degree of freedom (DOF) upper-limb exoskeleton in passive robot-assisted rehabilitation. The proposed method is c...

Obstacle avoidance is a significant skill not only for mobile robots but also for robot manipulators working in unstructured environments. Various algorithms have been proposed to solve off-line planning and on-line adaption problems. However, it is still not able to ensure safety and flexibility in complex scenarios. In this paper, a novel obstacl...

The upper-limb exoskeleton is capable of enhancing human arm strength beyond normal levels, whereas deriving the operator’s desired action straightforward turns out to be one of the significant difficulties facing human-robot interaction research. In the study, the human-robot interface was presented to regulate the exoskeleton tracking human elbow...

The shape memory alloy (SMA)-based robotic hand has been a new emerging technology with potential applications ranging from life service to surgical treatment, because of the characteristics of SMA, such as high power-to-weight ratio, small volume and low driving voltage. However, due to the complex dynamic model and nonlinear aspects of SMA, it is...

The proportional-integral (PI) control method is long well-known because of its simplicity as well as effectiveness. Although the PI control method overwhelmingly dominates engineering applications, the issue of developing a general PI control for nonlinear systems remains open. This paper considers the PI control problem for a family of unknown no...

Autonomous, flexible, and human–robot collaboration are the key features of the next-generation robot. Such unstructured and dynamic environments bring great challenges in online adaptive path planning. The robots have to avoid dynamic obstacles and follow the original task path as much as possible. A robust and efficient online path planning metho...

Imperfect information game is the difficulty in the game field. In the study of imperfect information games, an accurate and effective opponent modeling method is essential. Texas Hold 'em is a typical game with imperfect information. The main form of opponent modeling is to predict the opponent's behavior. This article takes Texas Hold 'em as the...

This paper focuses on the trajectory tracking issue of the pneumatic artificial muscle (PAM) exoskeleton system. First of all, a new type of the PAM elbow exoskeleton was introduced to assist wearers in elbow flexion/extension movement. Moreover, a model-free adaptive control approach was combined with the prescribed performance control to ensure t...

This paper concentrates on a simple and robust control method for the discrete time nonlinear systems to fulfill the requirement of predefined accuracy. A sliding mode control method is designed by introducing equivalent dynamic linearization technique according to the input/output (I/O) information merely. A square-root type error transformation m...

This paper proposes a data-driven sliding mode control (SMC) method with tracking error constraint for a shape memory alloy (SMA) actuated system. More specifically, a new SMC method with prescribed performance is investigated by adopting the equivalent dynamic linearization technique and a novel transformed error algorithm to guarantee that the tr...

This paper investigates the problem of the variable stiffness for a class of multisegment continuum manipulators. A simple design that mainly consists of two types of pneumatic muscle actuators (PMAs) is introduced to deal with the problem. To provide a detailed analysis, this characteristic of the variable stiffness is coupled with a mathematical...

The pneumatic artificial muscle (PAM) actuated with different input frequencies and mechanical loads suffers from complex dynamic asymmetric hysteresis behaviors, leading to inaccurate positioning performance of the PAM. In order to predict the dynamic hysteresis behaviors with both rate-dependent and load-dependent effects, a comprehensive dynamic...

Rolling bearings are the most frequently failed components in rotating machinery. Once a failure occurs, the entire system will be shut down or even cause catastrophic consequences. Therefore, a fault detection of rolling bearings is of great significance. Due to the complexity of the mechanical system, the randomness of the vibration signal appear...

The running of high-speed electrically driven feed pump has a direct impact on the safety of personnel equipment and economic benefits of power plant, as the result, intelligent condition monitoring and fault diagnosis of electrically driven feed pump becomes an urgent need. In the practical process of electrically driven feed pump fault diagnosis,...

This article investigates the problem of model-free tracking control for a class of continuum manipulators. A new type of robust control strategy is provided to address the problem, which primarily consists of two parts. First, to achieve output tracking with the desired accuracy, an error transformation scheme is constructed. Moreover, because of...

An innovative integration of actuating and sensing ionic polymer metal composite (IPMC) gripper is proposed and fabricated in this paper. The IPMC gripper is composed of a stationary copper finger and an IPMC finger attached to a force sensor. In order to make IPMC gripper useful in bio-manipulation application, control strategy is a critical facto...

Purpose Installing a tight tolerant stepped shaft is not a trivial task for an industrial robot. If all peg-hole constraints are complete, the cascaded peg-in-hole task can be simplified into several independent stages and accomplished one by one. However, if some of the constraints are incomplete, the cross stage interference will bring additional...

For designing the decision model of hybrid systems, there are sophisticated quantitative and qualitative attributes such as discrete events, continuous processes, stochasticity, and time delay. Meanwhile, the inherent heterogeneity and concurrency existing in hybrid systems trigger multiple decision challenges, including behavior uncertainty and st...

Soft manipulators can perform continuous operations due to their inherent compliance and dexterity, thus enabling safe interactions and smooth movements in confined environments. However, high compliance usually means low load capacity. It is important for a soft manipulator to possess proper flexibility while maintaining an acceptable stiffness to...

Cyber–physical system (CPS) is a multidimensional complex system that integrates computation, communication, and physical environment with essential and broad application prospects. However, there is a kind of CPS containing discrete events, continuous processes, stochastic phenomena, time-delay, and decision. It suffers from several sophisticated...

Currently, the gesture-based teleoperation system cannot generate precise and compliant robot motions because human motions have the characteristics of uncertainty and low-resolution. In this paper, a novel, gesture-based teleoperation system for compliant robot motion is proposed. By using the left hand as the commander and the right hand as a pos...

A pneumatic artificial muscle (PAM) consists mainly of an inner elastomeric bladder surrounded by a braided shell. Due to the special geometric structure, PAMs are subject to the typical drawbacks of a highly-asymmetric hysteresis-based nonlinear system. This paper presents a D-extended un-parallel Prandtl–Ishlinskii model (D-EUPI) model for modell...

Micro/nano positioning technologies have been attractive for decades in industrial and scientific applications fields. The actuators have inherent hysteresis that can cause system unexpected behave in some extend. In this research, the authors used extented unparallel Prandtl-Ishlinshii (EUPI) models to represent the input-output relationship of a...

For the nonlinear, time-variable and unpredictable environment (such as the manipulator workspace which has many random and moveable obstacles), a Hammerstein adaptive (HA) impedance controller based on a Hammerstein impedance model is proposed in this paper. The model consists of a static nonlinear element and a linear dynamic element, which can d...

This paper presents an assistance equipment of human elbow joint which aims to help patients who have elbow injury issues in smart campus environment. A new type of soft pneumatic elbow pad (SPEP) which adopted soft material manufacturing technology is presented. Compared with the rigid assistant equipment, the SPEP shows more comfort, smaller equi...

Soft robot arms possess such characteristics as light weight, simple structure and good adaptability to the environment, among others. On the other hand, robust control of soft robot arms presents many difficulties. Based on these reasons, this paper presents a novel design and modeling of a fuzzy active disturbance rejection control (FADRC) contro...

High power-to-weight ratio soft artificial muscles are of overarching importance to enable inherently safer solutions to human-robot interaction. Traditional air driven soft McKibben artificial muscles are linear actuators and it is impossible for them to realize bending motions through use of a single muscle. More than two McKibben muscles are nor...

A 3-DOF bionic elbow joint actuated by Pneumatic artificial muscle (PAM) was designed in this paper, and its inverse kinematics model was also established. Then, based on the Model-free adaptive control (MFAC) theory and the effects of control parameters to the control system, a Parameter self-adjust Model-free adaptive control (PSA-MFAC) strategy...

Scanning probe microscopy (SPM) technology plays the irreplaceable role in investigating micro/nano world, which has been bringing tremendous development opportunities to various fields. To enhance maneuverability, SPM can be modified into a nanomanipulation system with its scanning probe as the end-effector. The probe is commonly mounted on smart...

Pneumatic artificial muscle is a novel compliance actuator, and it has many excellent actuator characteristics, such as high power density, safety, and compliance. However, it also has strong nonlinear and asymmetric hysteresis, which makes the accurate trajectory control for a pneumatic artificial muscle very difficult. In this article, the pressu...

Atomic force microscope (AFM) has been defined as the one of the most powerful instruments to explore micro/nano-world in various fields. To lower imaging noise, AFMs are commonly equipped with open-loop nanopositioners (scanners). However, the hysteretic effect of the AFM positioners is a dominate factor that increases the position error during AF...

McKibben muscles have been shown to have improved stiffness characteristics when operating hydraulically. However when operating pneumatically, they are compliant and so have potential for safer physical human–robot interaction. This paper presents a method for rapidly switching between pneumatic and hydraulic modes of operation without the need to...

With the continuous development of intelligent robotics, intelligent robot can realize autonomous moving. Robot simultaneous localization and mapping technology arises at the historic moment. Adaptive monte carlo localization algorithm was used for mobile robot pose estimation. Bayesian algorithm was used to building grid map. The robot moving path...

This paper introduces the concept of PHM system and designs a virtual maintenance system based on PHM. The system architecture combined the service-oriented architecture and cloud computing. Choose free open-source alternative development environment to develop the system. The virtual maintenance system was exemplified that when using the system fo...

Research on robot suspension system is an effective way to improve the running stability of the tracked robot. This paper introduces the mechanical structure of the tracked robot and established the simulation model of tracked robot. The tracked robot was driving on a bumpy road simulation experiment by using RecurDyn simulation software. Through t...

Background: During the process of cell micro operation, the contact force between the entry needle and the cell membrane is usually a very small area to be tested. Objective: These two features have been utilized to design a high precision micro force sensor to provide a force feedback in the process of cell micro operation. Methods: However,...

Ionic polymer metal composite (IPMC) is a novel smart material which has been widely implemented in MEMS, biomimetic mechanical and electrical integrated system and micro operation system. While the IPMC with different shapes and dimensions has been implemented in many different types of biomechanical integrated systems, one of its inherent propert...

A new ionic polymer metal composite is fabricated by the addition of multiwalled carbon nanotubes into Nafion® in our study, which can be called multiwalled carbon nanotubes/ionic polymer metal composite. The Nafion membranes are doped with multiwalled carbon nanotubes forming multiwalled carbon nanotubes/Nafion, and the surface of composite electr...

In order to improve the performance of the tracking system, this paper discusses the trajectory tracking of the sun and tracing to the source of the sun. The experimental results show that: The automatic tracing of sun trajectory scheme runs smoothly without the interference of light source, but has model error; the automatic tracking of the sun so...

The interstitial fluid pressure (IFP) plays a major role in tumor formation. Increased IFP may hinder the tran-scapillary transport of therapeutic agents as well as the large molecules, and may also lead to a poor prognosis for some cancer patients. IFP may therefore be an important biomarker. Serial noninvasive IFP measurement in vivo may facilita...

Ionic polymer metal composites (IPMCs) are a type of electroactive polymer (EAP) that can be used as both sensors and actuators. An IPMC has enormous potential application in the field of biomimetic robotics, medical devices, and so on. However, an IPMC actuator has a great number of disadvantages, such as creep and time-variation, making it vulner...

Atomic force microscopy (AFM) based nanomanipulations have been successfully applied to various fields such as physics, material science and biomedical studies. In general, the precision of AFM based nanomanipulation has been compromised mainly by hysteresis and creep of the piezo actuator. In this paper, a new approach, named scan range adaptive h...

IPMC (Ion-exchange polymer metal composite) is a kind of novel artificial intelligent materials. It has a lot of good properties, such as light weight, good flexibility, easily cut in any size and shape, and can be used as both an actuator and sensor. A micro-force sensor based on the theory model of cantilever beam structure of IPMC is built up, w...

Most of traditional manipulator does not meet experimental requirements of micromanipulation for its large structure and complicated driven mode. Comparatively speaking, using actuating and sensing performance of IPMC gripper can well be applied to specific micro operations and mechanical testing environment. This paper designs one kind of IPMC gri...

Based on modal strain energy method, the paper discusses viscoelastic free layer damping sheet, establishes the finite element model of it and obtains the natural frequencies and loss factor. Then the paper calculates the loss factor of viscoelastic free layer damping structure with engineering empirical formula, and compares the result with that o...

On the basis of evolutionary structural optimization, the topology optimization for free layer damping cylindrical shell was studied. The checkerboard pattern problem caused by evolutionary structural optimization was solved by discrete independent mesh filter method. The programs of evolutionary structural optimization and discrete independent mes...

A bionic elbow joint driven by motor is lack of flexibility. So a good option is to improve the flexible and power density ratio. This paper has designed a 3-DOF bionic elbow joint based on pneumatic artificial muscle, and the simulation and forward kinematics analysis have been done. The simulation results show that the structure scheme is feasibl...

With the continuous development of LED(Light-Emitting Diode) manufacturing technology, the high power white LED is gradually applied in the field of all kinds of lighting .But with working time increasing of LED chips, their junctions temperature continue increasing, which lead to decrease light-emitting efficiency and reliability of LED chip, and...

Ionic polymer–metal composite (IPMC), also called artificial muscle, is an EAP material which can generate a relatively large deformation with a low driving voltage (generally less than 5 V). Like other EAP materials, IPMC possesses strong nonlinear properties, which can be described as a hybrid of back-relaxation (BR) and hysteresis characteristic...

Ionic polymer metal composites (IPMCs), also called artificial muscle, are actuators that lend themselves well to micro manipulators, micro-pump, biomimetics integrated application systems due to their lightweight, flexibility, ability to tailor their geometry, work in water environment, as well as the capability to be miniaturized and implanted in...

According to the feature of the magnetic actuation principle, now there are mainly three driving methods: one is alternating magnetic field, another is stationary gradient magnetic field and the last one is rotating magnetic field. This paper provides a detailed insight into the present-day state of microrobot technology and development on structur...

IPMC is a type of electro-active polymer material, also called artificial muscle, which can generate a relatively large deformation under a relatively low input voltage (generally speaking, less than 5 V), and can be implemented in a water environment. Due to these advantages, IPMC can be used in many fields such as biomimetics, service robots, bio...

IPMC (ionic polymer metal composites), also known as artificial muscles, is one kind smart material of electric actuators, it can generates a large deformation under a relatively low input voltage (generally less than 5V). Thin IPMC strips (the thickness is usually less than 0.3mm) possess a strong hysteresis and creep characteristics which will ch...

This paper proposes a remote control system based on cell injection robot. Analysis of the influence of network delay to control system performance with Matlab/Simulink toolbox TrueTime is done. The adoption of UDT protocol to transfer experimental image and control information in real-time lowers the network transfer delay and makes the microscopi...

This paper introduces the basic principle of the microscopic visual servoing system based on image and summarizes systematically about the researching situation of microscopic visual servo based on image at home and abroad. From three aspects, which are Jacobin matrix calculating, automatic focusing technology of microscopic lens, and microscopic i...