Zhaojie Ju

Dr. Zhaojie Ju

School of Computing, University of Portsmouth, Portsmouth, UK

Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 February 2021 in Sensors
Verified
Journal Article
Open access
PDF file
JHJiang Hua
Jiang Hua
LZLiangcai Zeng
Liangcai Zeng
GLGongfa Li
Gongfa Li
ZJZhaojie Ju
Zhaojie Ju
Dexterous manipulation of the robot is an important part of realizing intelligence, but manipulators can only perform simple tasks such as sorting and packing in a structured environment. In view of the existing problem, this paper presents a state-of-the-art survey on an intelligent robot with the capability of autonomous deciding and learning. The paper first reviews the main achievements and research of the robot, which were mainly based on the breakthrough of automatic control and hardware in mechanics. With the evolution of artificial intelligence, many pieces of research have made further progresses in adaptive and robust control. The survey reveals that the latest research in deep learning and reinforcement learning has paved the way for highly complex tasks to be performed by robots. Furthermore, deep reinforcement learning, imitation learning, and transfer learning in robot control are discussed in detail. Finally, major achievements based on these methods are summarized and analyzed thoroughly, and future research challenges are proposed.

20 November 2019 in IEEE Transactions on Cybernetics
Verified
Journal Article
Closed access
UOUchenna Emeoha Ogenyi
Uchenna Emeoha Ogenyi
JLJinguo Liu
Jinguo Liu
Chenguang YangChenguang Yang
Chenguang Yang
ZJZhaojie Ju
Zhaojie Ju
HLHonghai Honghai Liu
Honghai Honghai Liu
This article presents a state-of-the-art survey on the robotic systems, sensors, actuators, and collaborative strategies for physical human-robot collaboration (pHRC). This article starts with an overview of some robotic systems with cutting-edge technologies (sensors and actuators) suitable for pHRC operations and the intelligent assist devices employed in pHRC. Sensors being among the essential components to establish communication between a human and a robotic system are surveyed. The sensor supplies the signal needed to drive the robotic actuators. The survey reveals that the design of new generation collaborative robots and other intelligent robotic systems has paved the way for sophisticated learning techniques and control algorithms to be deployed in pHRC. Furthermore, it revealed the relevant components needed to be considered for effective pHRC to be accomplished. Finally, a discussion of the major advances is made, some research directions, and future challenges are presented.

17 May 2019 in IEEE Transactions on Industrial Electronics
Verified
Journal Article
Closed access
JPJianjun Peng
Jianjun Peng
FLFei Li
Fei Li
JLJinguo Liu
Jinguo Liu
ZJZhaojie Ju
Zhaojie Ju
Robot trajectory tracking control based on differential-algebraic equation (DAE) models is still a thorny issue, because the DAEs of such systems are inherently complex and unstable, such as the high index problem. In this paper, based on controlled DAEs, a symplectic instantaneous optimal control (IOC) method for robot trajectory tracking with input saturation is proposed. Based on the discrete variational principle and the canonical transformation, a symplectic discretization form for the controlled DAEs is first constructed. Then, the continuous trajectory tracking problem is approximated for a series of IOC problems at every time step, and the linear complementarity problem (LCP) can be derived for solving the IOC problems. Finally, the control inputs can be obtained by solving the corresponding standard LCP. The proposed method provides a unified framework for solving the trajectory tracking control problems of robot multibody dynamic systems. Numerical simulations and virtual experiments are conducted to verify the robustness and the efficiency of the proposed method, i.e., the input saturation constraints are satisfied at the discrete time points, and high accuracy tracking control results can be obtained at low computational cost.

2 February 2018 in Cluster Computing
Verified
Journal Article
Closed access
PDF file
DJDu Jiang
Du Jiang
ZZZujia Zheng
Zujia Zheng
GLGongfa Li
Gongfa Li
YSYing Sun
Ying Sun
JKJianyi Kong
Jianyi Kong
ZJZhaojie Ju
Zhaojie Ju

10 May 2021 in IEEE Sensors Journal
Verified
Journal Article
Closed access
QGQing Gao
Qing Gao
YCYonquan CHEN
Yonquan CHEN
ZJZhaojie Ju
Zhaojie Ju
YLYi Liang
Yi Liang
Dynamic hand gesture recognition is a challenging problem in the area of hand-based human–robot interaction (HRI), such as issues of a complex environment and dynamic perception. In the context of this problem, we learn from the principle of the data-glove-based hand gesture recognition method and propose a dynamic hand gesture recognition method based on 3D hand pose estimation. This method uses 3D hand pose estimation, data fusion and deep neural network to improve the recognition accuracy of dynamic hand gestures. First, a 2D hand pose estimation method based on OpenPose is improved to obtain a fast 3D hand pose estimation method. Second, the weighted sum fusion method is utilized to combine the RGB, depth and 3D skeleton data of hand gestures. Finally, a 3DCNN + ConvLSTM framework is used to identify and classify the combined dynamic hand gesture data. In the experiment, the proposed method is verified on a developed dynamic hand gesture database for HRI and gets 92.4% accuracy. Comparative experiment results verify the reliability and efficiency of the proposed method.

25 April 2017 in Paladyn
Verified
Journal Article
Open access
PDF file
PEPablo G. Esteban
Pablo G. Esteban
PBPaul Baxter
Paul Baxter
TBTony Belpaeme
Tony Belpaeme
EBErik Billing
Erik Billing
HCHaibin Cai
Haibin Cai
TZTom Ziemke
Tom Ziemke
Robot-Assisted Therapy (RAT) has successfully been used to improve social skills in children with autism spectrum disorders (ASD) through remote control of the robot in so-called Wizard of Oz (WoZ) paradigms.However, there is a need to increase the autonomy of the robot both to lighten the burden on human therapists (who have to remain in control and, importantly, supervise the robot) and to provide a consistent therapeutic experience. This paper seeks to provide insight into increasing the autonomy level of social robots in therapy to move beyond WoZ. With the final aim of improved human-human social interaction for the children, this multidisciplinary research seeks to facilitate the use of social robots as tools in clinical situations by addressing the challenge of increasing robot autonomy.We introduce the clinical framework in which the developments are tested, alongside initial data obtained from patients in a first phase of the project using a WoZ set-up mimicking the targeted supervised-autonomy behaviour. We further describe the implemented system architecture capable of providing the robot with supervised autonomy.