Chenglong Fu

Chenglong Fu
Southern University of Science and Technology | SUSTech · Department of Mechanical and Energy Engineering

Professor

About

143
Publications
19,685
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937
Citations

Publications

Publications (143)
Article
Visual information is indispensable to human locomotion in complex environments. Although amputees can perceive the environmental information by eyes, they cannot transmit the neural signals to prostheses directly. To augment human-prosthesis interaction, this article introduces a subvision system that can perceive environments actively, assist to...
Article
Walking with load carriage is a common requirement for individuals in many situations. Legged exoskeletons can transfer the load weight to the ground with rigid leg structures, thus reducing the load weight borne by the human user. However, the inertia of paralleled structures and the mechanical joint tend to disturb natural motions of human limbs,...
Article
The suspended backpack is a wearable robot applied in load carriage to reduce the energetic cost of human walking or harvest energy and generate electricity. An essential problem in the control objective of the suspended backpack is the unknown energetic response of humans, which would affect the human walking cost and energy harvesting efficiency....
Article
Full-text available
Leg stiffness is considered a prevalent parameter used in data analysis of leg locomotion during different gaits, such as walking, running, and hopping. Quantification of the change in support leg stiffness during stair ascent and descent will enhance our understanding of complex stair climbing gait dynamics. The purpose of this study is to investi...
Article
Actuation transparency and safety are impor- tant requirements in the design and control of assistive exoskeletons for individuals who suffer lower limb deficits but still maintain a certain level of voluntary motor control. In recent years, series elastic actuator (SEA) has been regarded as a promising solution for transparent actuation and safe h...
Article
In assistive robots, compliant actuator is a key component in establishing safe and satisfactory physical human–robot interaction (pHRI). The performance of compliant actuators largely depends on the stiffness of the elastic element. Generally, low stiffness is desirable to achieve low impedance, high fidelity of force control and safe pHRI, while...
Article
In dynamic outdoor environments characterized by turbulent airflow and intermittent odor plumes, robotic odor plume tracking remains challenging, because existing algorithms heavily rely on manually tuning or learning from expert experience, which are hard to implement in an unknown environment. In this paper, a multi-continuous-output Takagi–Sugen...
Chapter
With further development of brain-computer interface (BCI) technology and the BCI medicine field, people with movement disorders can be treated by using artificial limbs or some external devices such as an exoskeleton to achieve sports function rehabilitation. At present, brain-computer interfaces (BCI) based on motor imagination mainly have proble...
Preprint
Full-text available
Gait phase-based control is a trending research topic for walking-aid robots, especially robotic lower-limb prostheses. Gait phase estimation is a challenge for gait phase-based control. Previous researches used the integration or the differential of the human's thigh angle to estimate the gait phase, but accumulative measurement errors and noises...
Article
Full-text available
Fuzzy inference systems have been widely applied in robotic control. Previous studies proposed various methods to tune the fuzzy rules and the parameters of the membership functions (MFs). Training the systems with only supervised learning requires a large amount of input-output data, and the performance of the trained system is confined by that of...
Preprint
Full-text available
In assistive robots, compliant actuator is a key component in establishing safe and satisfactory physical human-robot interaction (pHRI). The performance of compliant actuators largely depends on the stiffness of the elastic element. Generally, low stiffness is desirable to achieve low impedance, high fidelity of force control and safe pHRI, while...
Article
Full-text available
Powered lower-limb prostheses with vision sensors are expected to restore amputees' mobility in various environments with supervised learning-based environmental recognition. Due to the sim-to-real gap, such as real-world unstructured terrains and the perspective and performance limitations of vision sensor, simulated data cannot meet the requireme...
Article
The objective of this paper is to develop a theory for designing the keyboard area of smartphones, and endowing the users with comfortable texting ability via one thumb. In light of the fact that most users tend to hold the smartphone in one hand and manipulate with one thumb in daily life, this paper extracts the thumb kinematic chain from the thu...
Article
In recent years, lower-limb exoskeletons have been applied to assist people with weak mobility in daily life, which requires enhanced adaptability to complex environments. To achieve a smooth transition between different assistive strategies and provide proper assistance at the desired timing during locomotion on various terrains, two significant i...
Preprint
Full-text available
Recognizing human locomotion intent and activities is important for controlling the wearable robots while walking in complex environments. However, human-robot interface signals are usually user-dependent, which causes that the classifier trained on source subjects performs poorly on new subjects. To address this issue, this paper designs the ensem...
Article
An important goal for humanoid robots is to achieve fast, flexible and stable walking. In previous research, the structure and walking algorithms evolved separately, resulting in a slow evolution speed and lack of an initial design basis. This paper proposes comprehensively considering body morphology and walking patterns, exploring the relationshi...
Article
Human activities recognition (HAR) and human intent recognition (HIR) are important for medical diagnosis and human-robot interaction. HAR and HIR usually rely on the signals of some wearable sensors, such as inertial measurement unit (IMU), but these signals may be user-dependent, which degrades the performance of the recognition algorithm on new...
Article
Full-text available
Estimation of center of mass (CoM) and center of pressure (CoP) is critical for lower limb exoskeletons, prostheses, and legged robots. To meet the demand in these fields, this study presents a novel CoM and CoP estimation method for human walking through a wearable visual odometry (VO) device. This method is named VO-based estimation of CoM and Co...
Article
The mechanical work performed by the individual legs affects the metabolic cost of locomotion. The effects of an elastically suspended backpack (ESB) on the mechanical work performed by the individual legs have not yet been quantified. This article explores the impact of variables, such as the stiffness and damper of an ESB, walking speed, and load...
Article
Full-text available
Predicting the next foot placement of humans during walking can help improve compliant interactions between humans and walking aid robots. Previous studies have focused on foot placement estimation with wearable inertial sensors after heel-strike, but few have predicted foot placements in advance during the early swing phase. In this study, a Bayes...
Article
Full-text available
Wearable robots, such as exoskeletons, can potentially reduce the load at targeted muscles of the human body during fatiguing tasks. It is common, however, that use of a wearable robot causes increased load at untargeted muscles, leading to minimal net improvement. Here, musculoskeletal impacts of a wearable robotic device are examined to establish...
Conference Paper
Learning through a point cloud is attractive be- cause a point cloud contains geometric data and can help robots understand environments in a robust manner. However, a point cloud is sparse, unstructured and unordered, and its accurate recognition by a traditional convolutional neural network (CNN) or a recurrent neural network (RNN) is difficult....
Conference Paper
Load carriage is a common demand in humans’ daily life. Long time load carriage often causes significant energy expenditure for the body and may even bring physical problems like muscle strain. Variations in terrains and ground conditions are usually inevitable in such scenarios, which disrupts humans’ gait and leads to even more energy expenditure...
Conference Paper
Foot placement early prediction is important for designing compliant controllers for wearable robotic systems. There have been many researches on human walking gait analysis, but most of them focus on historic foot placement measurement and estimation, the work on foot placement early prediction has been rarely seen. This paper investigated three m...
Conference Paper
Most of the powered lower-limb exoskeletons are bulky or complex to wear. Especially, some exoskeletons have constraints on human leg movement. These all limit their applicability to daily walking assistance. In this paper, the ankle joint is selected to be assisted based on the fact that ankle joint contributes most of the positive power in daily...
Article
In this paper, we present an underactuated soft exoskeleton which can sequentially provide knee extension and ankle plantarflexion assistance for each leg with only one motor. The aim of this work is to assist the motions that have chronological moments at lower-limb joints and minimize the mass carried by the wearer. The underactuated soft exoskel...
Article
Full-text available
Upper limb exoskeletons have drawn significant attention in neurorehabilitation because of the anthropomorphic mechanical structure analogous to human anatomy. Whereas, the training movements are typically unorganized because most exoskeletons ignore the natural movement characteristic of human upper limbs, particularly inter-joint postural synergy...
Preprint
Full-text available
Supernumerary Robotics Device (SRD) is an ideal solution to provide robotic assistance in overhead manual manipulation. Since two arms are occupied for the overhead task, it is desired to have additional arms to assist us in achieving other subtasks such as supporting the far end of a long plate and pushing it upward to fit in the ceiling. In this...
Conference Paper
In order to offer appropriate and reliable assistance to users, wearable robotic devices usually detect human locomotion through multi-sensor fusion system. However, multi-sensor fusion system increased the complexity of the sensor system and the burden of wearing on users for ankle exoskeleton. To optimize the sensor system and recognize multi-gai...
Conference Paper
Wearable robotic systems have been widely studied in recent years, but it still remains a challenge to design a user-adaptive controller for wearable robotic systems to ensure personalized and accurate human-robot interaction. Accurate human motion classification and person identification are two premises helping design user-adaptive controllers fo...
Article
Full-text available
Robotic odor/gas source localization is a widely studied field, but most of the existing works are about rule-based algorithms. In this paper, the Deep Q-Network algorithm is applied to solve the odor source localization problem. An odor hits distribution model is proposed to model the odor concentration distribution in indoor environments, taking...
Article
Full-text available
Overhead manipulation often needs collaboration of two operators, which is challenging in confined space such as in a compartment or on a ladder. Supernumerary Robotic Limb (SuperLimb), as a promising wearable robotics solution for overhead tasks, can provide optimal assistance in terms of broader workspace, diverse manipulation functionalities, an...
Article
Full-text available
During COVID-19, with a heavy sprayer filled with disinfectant, the risk of infection for epidemic prevention personnel has been increased by long-term environmental disinfection. In order to reduce the burden and save energy of human, this paper proposed a Wheel-Legged Robotic Limb (WRL) for the carriers. The mass of WRL is only 1.77 kg. The WRL h...
Article
Predicting the locomotion intent of humans is important for controlling assistive robots predictively. Previous studies have researched assistive walking on structured terrains, but few studies consider rough terrains. Human intent on rough terrains is more difficult to predict because the transition happens every step. To predict foot placements o...
Article
Full-text available
Loaded walking with typical rigid backpack results in a significant increase in the mechanical energy of the stance leg and a decrease in lateral stability. Allowing the load to swing, which has been applied in shoulder pole, a tool widely used in Asia for load carriage assistance, may attenuate these effects. This paper theoretically analyzes and...
Conference Paper
Stair ascending is laborious, which imposes very high load on human knee, leading to high risks of knee injuries. Therefore, in this paper, a biologically-inspired soft exosuit for knee extension assistance during stair ascent was designed and the assistant effect of proposed exosuit was evaluated. We placed Bowden cables in front of thigh and shan...
Conference Paper
Based on the fact that push-off force is the main energy input of human walking, reducing the push-off force when carrying the load is helpful to improve the walking endurance. Previous work has proved that an elastically suspended backpack could change ground reaction forces (GRFs) of legs, and parameters of elastically suspended backpack and walk...
Conference Paper
Compliance is important for humanoid robots, especially a position-controlled one, to perform tasks in complicated environments where unexpected or sudden contacts will result in large impacts which may cause instability or destroy the hardware of robots. This paper presents a compliance control method based on viscoelastic model for humanoid robot...
Conference Paper
State estimation is an important part of biped robot control, but unreliable foot contact estimation would lead to inaccurate state estimation result. In this paper, to reduce the state estimation error caused by the inaccurate contact estimation, we propose a novel simplified contact probability estimator based on the force/torque sensor mounted o...
Article
Background: Leg muscle fatigue is the most important factor that affects walking endurance. Considering the legs act as actuators in alternate contact with the ground during walking, the ground reaction force (GRF) of each leg can indirectly reflect the strength of leg muscles. However, it is not clear how the elastically-suspended backpack (ESB)...
Preprint
Full-text available
Reinforcement learning (RL) is a popular data-driven method that has demonstrated great success in robotics. Previous works usually focus on learning an end-to-end (direct) policy to directly output joint torques. While the direct policy seems convenient, the resultant performance may not meet our expectations. To improve its performance, more soph...
Article
Loaded walking with a rucksack results in both gravitational and inertial forces of the load that must be borne by human carriers. The inertial force may be the source of metabolic burden and musculoskeletal injuries. This paper presents a lightweight backpack with a disturbance observer-based acceleration control to minimize the inertial force. Th...
Conference Paper
Full-text available
Supernumerary Robotics Device (SRD) or Supernumerary Robotic Limbs (SRL) is an ideal solution to provide robotic assistance in overhead manual manipulation, especially the tasks including supporting a panel and fitting it in the ceiling in limited space such as compartment. Since two arms are occupied for the overhead task, it is desired to have ad...
Article
IMU-based human joint motion acquisition system is attractive for real-time control and monitoring in the emerging wearable technology due to its portability. However, in practical applications, it heavily suffers from long-term drift, magnetic interference and inconsistency of rotational reference frames, which causes precision degradation. In thi...
Conference Paper
Full-text available
Many researchers have identified robotics as a potential solution to the aging population faced by many developed and developing countries. If so, how should we address the cognitive acceptance and ambient control of elderly assistive robots through design? In this paper, we proposed an explorative design of an ambient SuperLimb (Supernumerary Robo...
Article
This paper presents the design and preliminary evaluation of a quasi-passive lower limb exoskeleton that was designed to improve walking efficiency. During walking, lower limb joints perform both positive and negative work. The exoskeleton recycles the negative mechanical work performed by knee joint in late swing and ankle joint in mid-stance, to...
Article
Full-text available
This paper investigates the energy performance of human load carriage with a variable damped suspended backpack. A vertical double-mass coupled-oscillator model is adopted to predict the load movement and energy consumption. Optimal control is found to be bang-bang, switching four times between the minimum and the maximum damping in a step cycle. W...
Preprint
Many researchers have identified robotics as a potential solution to the aging population faced by many developed and developing countries. If so, how should we address the cognitive acceptance and ambient control of elderly assistive robots through design? In this paper, we proposed an explorative design of an ambient SuperLimb (Supernumerary Robo...
Preprint
The optimal policy of a reinforcement learning problem is often discontinuous and non-smooth. I.e., for two states with similar representations, their optimal policies can be significantly different. In this case, representing the entire policy with a function approximator (FA) with shared parameters for all states maybe not desirable, as the gener...
Article
Accurately predicting human locomotion intent is beneficial in controlling wearable robots and in assisting humans to walk smoothly on different terrains. Traditional methods for predicting human locomotion intent require collecting and labeling the human signals, and training specific classifiers for each new subject, which introduce a heavy burde...
Article
2020 IEEE. Many researchers have identified robotics as a potential solution to the aging population faced by many developed and developing countries. If so, how should we address the cognitive acceptance and ambient control of elderly assistive robots through design? In this paper, we proposed an explorative design of an ambient SuperLimb (Supernu...
Article
Full-text available
Currently, with the satisfaction of people’s material life, sports, like yoga and tai chi, have become essential activities in people’s daily life. For most yoga amateurs, they could only learn yoga by self-study, like mechanically imitating from yoga video. They could not know whether they performed standardly without feedback and guidance. In thi...
Conference Paper
Unlike western conventions of rigid body attachments (e.g. backpack), carriers in Asia prefer to use bamboo poles, an ancient, ingenious, elastically-suspended equipment, especially when carrying heavy loads. As an elastically-suspended equipment, bamboo pole might have some potential benefits including reducing peak shoulder forces as well as savi...
Preprint
Full-text available
Controlling a biped robot to walk stably is a challenging task considering its nonlinearity and hybrid dynamics. Reinforcement learning can address these issues by directly mapping the observed states to optimal actions that maximize the cumulative reward. However, the local minima caused by unsuitable rewards and the overestimation of the cumulati...
Article
Powered prostheses are effective for helping amputees walk in a single environment, but these devices are inconvenient to use in complex environments. In order to help amputees walk in complex environments, prostheses need to understand the motion intent of amputees. Recently, researchers have found that vision sensors can be utilized to classify e...