This page has only limited features, please log in for full access.

Unclaimed
Xiaofeng Wu
School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia

Basic Info

Basic Info is private.

Honors and Awards

The user has no records in this section


Career Timeline

The user has no records in this section.


Short Biography

The user biography is not available.
Following
Followers
Co Authors
The list of users this user is following is empty.
Following: 0 users

Feed

Journal article
Published: 12 February 2021 in Applied Sciences
Reads 0
Downloads 0

Cold spray is emerging as an additive manufacturing technique, particularly advantageous when high production rate and large build sizes are in demand. To further accelerate technology’s industrial maturity, the problem of geometric control must be improved, and a neural network model has emerged to predict additively manufactured geometry. However, limited data on the effect of deposition conditions on geometry growth is often problematic. Therefore, this study presents data-efficient neural network modelling of a single-track profile in cold spray additive manufacturing. Two modelling techniques harnessing prior knowledge or existing model were proposed, and both were found to be effective in achieving the data-efficient development of a neural network model. We also showed that the proposed data-efficient neural network model provided better predictive performance than the previously proposed Gaussian function model and purely data-driven neural network. The results indicate that a neural network model can outperform a widely used mathematical model with data-efficient modelling techniques and be better suited to improving geometric control in cold spray additive manufacturing.

ACS Style

Daiki Ikeuchi; Alejandro Vargas-Uscategui; Xiaofeng Wu; Peter King. Data-Efficient Neural Network for Track Profile Modelling in Cold Spray Additive Manufacturing. Applied Sciences 2021, 11, 1654 .

AMA Style

Daiki Ikeuchi, Alejandro Vargas-Uscategui, Xiaofeng Wu, Peter King. Data-Efficient Neural Network for Track Profile Modelling in Cold Spray Additive Manufacturing. Applied Sciences. 2021; 11 (4):1654.

Chicago/Turabian Style

Daiki Ikeuchi; Alejandro Vargas-Uscategui; Xiaofeng Wu; Peter King. 2021. "Data-Efficient Neural Network for Track Profile Modelling in Cold Spray Additive Manufacturing." Applied Sciences 11, no. 4: 1654.

Journal article
Published: 27 January 2021 in Acta Astronautica
Reads 0
Downloads 0

This paper developed and tested a micro air-fed magnetoplasmadynamic thruster for small satellites. The thruster is a type of miniaturized electric propulsion system designed base on conventional full scale magnetoplasmadynamic thruster that operates at hundreds of kilowatts power. The thruster is designed and tested using normal air as the propellant under the pulse operation mode on a calibrated micro-force measurement thruster stand. The experiments revealed that the thruster can generate a 34.534 μNs impulse bit with an average power input of 1.857 ± 0.0679 W and thrust to power ratio of 8.266 μN/W, and the specific impulse is calculated to be 2319 s with the thruster efficiency of 9.402%, which is quite competitive comparing with other solid-state and liquid-fed pulse-mode thrusters. This paper presents the design and test results for the thruster under a low power level as well as an analysis of its problems and limitations with corresponding future research and optimization directions noted at the end.

ACS Style

Zihao Wang; Youngho Eun; Xiaofeng Wu. Design and demonstration of a micro air-fed magnetoplasmadynamic thruster for small satellites. Acta Astronautica 2021, 181, 482 -491.

AMA Style

Zihao Wang, Youngho Eun, Xiaofeng Wu. Design and demonstration of a micro air-fed magnetoplasmadynamic thruster for small satellites. Acta Astronautica. 2021; 181 ():482-491.

Chicago/Turabian Style

Zihao Wang; Youngho Eun; Xiaofeng Wu. 2021. "Design and demonstration of a micro air-fed magnetoplasmadynamic thruster for small satellites." Acta Astronautica 181, no. : 482-491.

Research article
Published: 12 November 2020 in Mathematical Problems in Engineering
Reads 0
Downloads 0

According to the trajectory specialty of hypersonic boost-glide vehicles, a strapdown inertial navigation system/BeiDou navigation satellite system (SINS/BDS) algorithm based on the launch-centered inertial (LCI) frame for hypersonic vehicles is proposed. First, the related frame system, especially the launch earth-centered inertial (LECI) frame, and the SINS mechanization in the LCI frame are introduced. Second, SINS discrete updating algorithms in the LCI frame for the compensation of coning, sculling, and scrolling effects are deduced in the attitude, velocity, and position updating algorithms, respectively. Subsequently, the Kalman filter of the SINS/BDS integrated navigation in the LCI frame is obtained. The method of converting BDS receiver position and velocity from the Earth-centered Earth-fixed (ECEF) frame to the LCI frame is deduced through the LECI frame. Finally, taking the typical hypersonic boost-glide vehicles as the object, the SINS/BDS algorithm vehicle field test and hardware-in-the-loop simulation are performed.

ACS Style

Kai Chen; Fuqiang Shen; Jun Zhou; Xiaofeng Wu. SINS/BDS Integrated Navigation for Hypersonic Boost-Glide Vehicles in the Launch-Centered Inertial Frame. Mathematical Problems in Engineering 2020, 2020, 1 -16.

AMA Style

Kai Chen, Fuqiang Shen, Jun Zhou, Xiaofeng Wu. SINS/BDS Integrated Navigation for Hypersonic Boost-Glide Vehicles in the Launch-Centered Inertial Frame. Mathematical Problems in Engineering. 2020; 2020 ():1-16.

Chicago/Turabian Style

Kai Chen; Fuqiang Shen; Jun Zhou; Xiaofeng Wu. 2020. "SINS/BDS Integrated Navigation for Hypersonic Boost-Glide Vehicles in the Launch-Centered Inertial Frame." Mathematical Problems in Engineering 2020, no. : 1-16.

Journal article
Published: 23 October 2020 in Materials
Reads 0
Downloads 0

Currently, it appears that there is a lack of understanding related to the role of SSF, in the two-phase behavior of the deceleration history, which is an issue discussed recently in the impact dynamics field. This paper analytically and numerically focuses on the effect of SSF on the projectile deceleration characteristic of concrete-like targets. Firstly, the penetration process according to the two-phase feature of the projectile deceleration is revised, where analytical results indicate that the SSF has a phased feature corresponding to the two-phase behavior of the deceleration history. Furthermore, a series of numerical simulations are conducted to understand the role of SSF more clearly. Simulation results show a similar conclusion to the analyses of the two-phase penetration process; at the range below a certain critical striking velocity, adding friction can reproduce the experimental data; when exceeding the critical striking velocity, the simulated results without considering friction are closest to the experimental data. Hence, it could be gained that the role exchange between the SSF and the dynamic term contributes to the two-phase penetration behavior for concrete-like materials. This indicates that the sensitivity of SSF to the penetration process is one of the factors driving the two-phase feature.

ACS Style

Ningjing Jiang; Shufan Wu; Yile Hu; Zhongcheng Mu; Xiaofeng Wu; Wei Zhang. Investigations into the Role of Friction for Rigid Penetration into Concrete-Like Material Targets. Materials 2020, 13, 4733 .

AMA Style

Ningjing Jiang, Shufan Wu, Yile Hu, Zhongcheng Mu, Xiaofeng Wu, Wei Zhang. Investigations into the Role of Friction for Rigid Penetration into Concrete-Like Material Targets. Materials. 2020; 13 (21):4733.

Chicago/Turabian Style

Ningjing Jiang; Shufan Wu; Yile Hu; Zhongcheng Mu; Xiaofeng Wu; Wei Zhang. 2020. "Investigations into the Role of Friction for Rigid Penetration into Concrete-Like Material Targets." Materials 13, no. 21: 4733.

Journal article
Published: 21 September 2020 in Sensors
Reads 0
Downloads 0

In this study, a simulation platform for an integrated navigation algorithm for hypersonic vehicles based on flight mechanics is designed. In addition, the generation method of inertial measurement unit data and satellite receiver data is introduced. First, the interface relationship between a high-precision six-degree-of-freedom (6DoF) model and the simulation platform in the launch-centered Earth-fixed frame is introduced. Three-axis theoretical specific force and angular velocity are output by the 6DoF model. Accelerometer and gyroscope error models are added, and integral processing of the specific force and angular velocity is performed to obtain velocity increment of the accelerometer and the angular increment of the gyroscope. These data are quantified to obtain the accelerometer and gyroscope pulses. The satellite’s pseudo-range and pseudo-range rate as well as its position and velocity are obtained from the theoretical position, velocity, the attitude of the hypersonic vehicle’s 6DoF model output, and the global positioning system (GPS) satellite broadcast ephemeris. The simulation data can be used for the verification of the loose and tight coupling integrated navigation algorithms. The simulation test verifies the accuracy of the designed method.

ACS Style

Kai Chen; Fuqiang Shen; Jun Zhou; Xiaofeng Wu. Simulation Platform for SINS/GPS Integrated Navigation System of Hypersonic Vehicles Based on Flight Mechanics. Sensors 2020, 20, 5418 .

AMA Style

Kai Chen, Fuqiang Shen, Jun Zhou, Xiaofeng Wu. Simulation Platform for SINS/GPS Integrated Navigation System of Hypersonic Vehicles Based on Flight Mechanics. Sensors. 2020; 20 (18):5418.

Chicago/Turabian Style

Kai Chen; Fuqiang Shen; Jun Zhou; Xiaofeng Wu. 2020. "Simulation Platform for SINS/GPS Integrated Navigation System of Hypersonic Vehicles Based on Flight Mechanics." Sensors 20, no. 18: 5418.

Journal article
Published: 10 July 2020 in IEEE Access
Reads 0
Downloads 0

This paper presents a new adaptive small chattering sliding mode control (SCSMC) scheme that uses reinforcement learning (RL) and time-delay estimation (TDE) for the motion control of free-floating space robotic manipulators (FSRM) subject to model uncertainty and external disturbance. The proposed sliding mode control scheme can achieve small chattering effects and improve the tracking accuracy by using a new adaptive law for the switching gain and a RL-based robust term to handle the control inputs. In SCSMC, the complicated multiple-input-multiple-output (MIMO) uncertain system of FSRM is transformed into multiple single-input-single-output (SISO) known subsystems with bounded estimation errors by the TDE technique and state feedback compensation. Subsequently, once the sliding variable is inside the designed manifold, the derivative of the switching gain for each subsystem becomes a negative hyperbolic tangent function of the associated sliding variable, which offers the ability to reduce chattering by decreasing the switching gain. Moreover, the RL based robust term for each subsystem is designed to avoid the loss of tracking accuracy caused by the aforementioned switching gain drop. The tracking errors are proven to be uniformly-ultimately-bounded (UUB) with an arbitrarily small bound by using the Lyapunov theory. The effectiveness of the proposed control scheme is verified by numerical simulations.

ACS Style

Zhicheng Xie; Tao Sun; Trevor Hocksun Kwan; Zhongcheng Mu; Xiaofeng Wu. A New Reinforcement Learning Based Adaptive Sliding Mode Control Scheme for Free-Floating Space Robotic Manipulator. IEEE Access 2020, 8, 127048 -127064.

AMA Style

Zhicheng Xie, Tao Sun, Trevor Hocksun Kwan, Zhongcheng Mu, Xiaofeng Wu. A New Reinforcement Learning Based Adaptive Sliding Mode Control Scheme for Free-Floating Space Robotic Manipulator. IEEE Access. 2020; 8 ():127048-127064.

Chicago/Turabian Style

Zhicheng Xie; Tao Sun; Trevor Hocksun Kwan; Zhongcheng Mu; Xiaofeng Wu. 2020. "A New Reinforcement Learning Based Adaptive Sliding Mode Control Scheme for Free-Floating Space Robotic Manipulator." IEEE Access 8, no. : 127048-127064.

Journal article
Published: 18 June 2020 in Acta Astronautica
Reads 0
Downloads 0

The free-flying space manipulators present challenges in controlling the motions of both the spacecraft bus and the manipulator, because of the highly-coupling system dynamics and the unknown space environment disturbances. Although the sliding mode controllers are robust to the unknown disturbances and system uncertainties, the chattering effect could affect the pointing accuracy and the lifetime of the actuators. This paper first introduces the dynamics of a CuBot, which is a 3-rigid-link manipulator based on the CubeSat platform. To maintain the robustness while decreasing the chattering effect, an innovative reinforcement learning based fuzzy adaptive sliding mode controller is proposed. To maintain the robustness while reducing the chattering effect, an innovative reinforcement learning based fuzzy adaptive sliding mode controller is proposed. The switching gain is updated to estimate the lumped upper bound of the system uncertainties and the unknown disturbances, and then a new fuzzy logic adaptive law is applied on the switching gain to decrease the chattering effects. On top of that, the fuzzy logic rules are tuned by an innovative modified reinforcement learning mechanism to achieve the better tracking performance. The uniformly ultimately bounded tracking errors are guaranteed by the proposed control scheme, and the effectiveness is validated by the simulation results.

ACS Style

Zhicheng Xie; Tao Sun; Trevor Kwan; Xiaofeng Wu. Motion control of a space manipulator using fuzzy sliding mode control with reinforcement learning. Acta Astronautica 2020, 176, 156 -172.

AMA Style

Zhicheng Xie, Tao Sun, Trevor Kwan, Xiaofeng Wu. Motion control of a space manipulator using fuzzy sliding mode control with reinforcement learning. Acta Astronautica. 2020; 176 ():156-172.

Chicago/Turabian Style

Zhicheng Xie; Tao Sun; Trevor Kwan; Xiaofeng Wu. 2020. "Motion control of a space manipulator using fuzzy sliding mode control with reinforcement learning." Acta Astronautica 176, no. : 156-172.

Journal article
Published: 15 November 2019 in Control Engineering Practice
Reads 0
Downloads 0

Previously, the combined thermoelectric generator and cooler (TEG-TEC) control technique was proposed for thermal management of devices, where the TEG mode is used for energy harvesting and the TEC mode is used for active temperature control. This research significantly improves the TEG-TEC control technique by including the components that ensure the TEG output power can truly be returned to the original power source. Specifically, two cascaded boost converters are adopted in the TEG power circuit where the former is used to achieve maximum power point tracking, and the latter provides an additional constant voltage gain to improve the circuit’s compatibility. Both a Simscape based simulation model and the modified experimental platform involving a lithium ion battery is used to demonstrate the improved implementation. Moreover, for the sake of demonstration, two control algorithms, namely the basic nested IF loop and a fuzzy logic controller, are adopted and their performances are compared. Finally, a steady state analysis of the Simscape model involving a parametric sweep of the input waste heat shows that the TEG mode can only be engaged for a certain range.

ACS Style

Trevor Hocksun Kwan; Xiaofeng Wu; Qinghe Yao. Complete implementation of the combined TEG-TEC temperature control and energy harvesting system. Control Engineering Practice 2019, 95, 104224 .

AMA Style

Trevor Hocksun Kwan, Xiaofeng Wu, Qinghe Yao. Complete implementation of the combined TEG-TEC temperature control and energy harvesting system. Control Engineering Practice. 2019; 95 ():104224.

Chicago/Turabian Style

Trevor Hocksun Kwan; Xiaofeng Wu; Qinghe Yao. 2019. "Complete implementation of the combined TEG-TEC temperature control and energy harvesting system." Control Engineering Practice 95, no. : 104224.

Journal article
Published: 04 November 2019 in Algorithms
Reads 0
Downloads 0

This paper presents a space mission planning tool, which was developed for LEO (Low Earth Orbit) observation satellites. The tool is focused on a two-phase planning strategy with clustering preprocessing and mission planning, where an improved clustering algorithm is applied, and a hybrid algorithm that combines the genetic algorithm with the simulated annealing algorithm (GA–SA) is given and discussed. Experimental simulation studies demonstrate that the GA–SA algorithm with the improved clique partition algorithm based on the graph theory model exhibits higher fitness value and better optimization performance and reliability than the GA or SA algorithms alone.

ACS Style

Xiangyu Long; Shufan Wu; Xiaofeng Wu; Yixin Huang; Zhongcheng Mu. A GA-SA Hybrid Planning Algorithm Combined with Improved Clustering for LEO Observation Satellite Missions. Algorithms 2019, 12, 231 .

AMA Style

Xiangyu Long, Shufan Wu, Xiaofeng Wu, Yixin Huang, Zhongcheng Mu. A GA-SA Hybrid Planning Algorithm Combined with Improved Clustering for LEO Observation Satellite Missions. Algorithms. 2019; 12 (11):231.

Chicago/Turabian Style

Xiangyu Long; Shufan Wu; Xiaofeng Wu; Yixin Huang; Zhongcheng Mu. 2019. "A GA-SA Hybrid Planning Algorithm Combined with Improved Clustering for LEO Observation Satellite Missions." Algorithms 12, no. 11: 231.

Journal article
Published: 02 September 2019 in Materials
Reads 0
Downloads 0

Cold spray additive manufacturing is an emerging technology that offers the ability to deposit oxygen-sensitive materials and to manufacture large components in the solid state. For further development of the technology, the geometric control of cold sprayed components is fundamental but not yet fully matured. This study presents a neural network predictive modelling of a single-track profile in cold spray additive manufacturing to address the problem. In contrast to previous studies focusing only on key geometric feature predictions, the neural network model was employed to demonstrate its capability of predicting complete track profiles at both normal and off-normal spray angles, resulting in a mean absolute error of 8.3%. We also compared the track profile modelling results against the previously proposed Gaussian model and showed that the neural network model provided comparable predictive accuracy, even outperforming in the predictions at cold spray profile edges. The results indicate that a neural network modelling approach is well suited to cold spray profile prediction and may be used to improve geometric control during additive manufacturing with an appropriate process planning algorithm.

ACS Style

Daiki Ikeuchi; Alejandro Vargas-Uscategui; Xiaofeng Wu; Peter C. King. Neural Network Modelling of Track Profile in Cold Spray Additive Manufacturing. Materials 2019, 12, 2827 .

AMA Style

Daiki Ikeuchi, Alejandro Vargas-Uscategui, Xiaofeng Wu, Peter C. King. Neural Network Modelling of Track Profile in Cold Spray Additive Manufacturing. Materials. 2019; 12 (17):2827.

Chicago/Turabian Style

Daiki Ikeuchi; Alejandro Vargas-Uscategui; Xiaofeng Wu; Peter C. King. 2019. "Neural Network Modelling of Track Profile in Cold Spray Additive Manufacturing." Materials 12, no. 17: 2827.

Journal article
Published: 21 June 2019 in Applied Thermal Engineering
Reads 0
Downloads 0

Although the integration of heat pumps with fuel cells for micro combined heat and power is a viable solution for reducing hydrogen energy consumption, recent studies have typically only considered the vapour compression cycle as the selected heat pump. This research proposes a multi-objective optimisation methodology to analyse the performance of several candidate heat pump technologies (the Peltier device, trans-critical R744 cycle, and vapour compression cycle), and determines the most suitable option for the hybrid fuel cell and heat pump (FC-HP-μCHP) system. Their mathematical models have been separately developed and utilised in a transient simulation for satisfying the power and heat demands of a domestic home. The selected optimisation objectives include maximising the hydrogen energy consumption efficiency and minimising the combined capital and yearly maintenance costs. Results show that the vapour compression cycle is the dominant solution. This is because it has the highest coefficient of performance, and effectively reduced the fuel cell stack and lithium battery’s maintenance costs. The heat pump’s coefficient of performance is found to have higher importance than its own economic cost.

ACS Style

Trevor Hocksun Kwan; Xiaofeng Wu; Qinghe Yao. Performance comparison of several heat pump technologies for fuel cell micro-CHP integration using a multi-objective optimisation approach. Applied Thermal Engineering 2019, 160, 114002 .

AMA Style

Trevor Hocksun Kwan, Xiaofeng Wu, Qinghe Yao. Performance comparison of several heat pump technologies for fuel cell micro-CHP integration using a multi-objective optimisation approach. Applied Thermal Engineering. 2019; 160 ():114002.

Chicago/Turabian Style

Trevor Hocksun Kwan; Xiaofeng Wu; Qinghe Yao. 2019. "Performance comparison of several heat pump technologies for fuel cell micro-CHP integration using a multi-objective optimisation approach." Applied Thermal Engineering 160, no. : 114002.

Book chapter
Published: 22 May 2019 in Introduction and Implementations of the Kalman Filter
Reads 0
Downloads 0

Autonomous aerospace systems may well soon become ubiquitous pending an increase in autonomous capability. Greater autonomous capability means there is a need for high-performance state estimation. However, the desire to reduce costs through simplified development processes and compact form factors can limit performance. A hardware-based approach, such as using a field-programmable gate array (FPGA), is common when high performance is required, but hardware approaches tend to have a more complicated development process when compared to traditional software approaches; greater development complexity, in turn, results in higher costs. Leveraging the advantages of both hardware-based and software-based approaches, a hardware/software (HW/SW) codesign of the unscented Kalman filter (UKF), based on an FPGA, is presented. The UKF is split into an application-specific part, implemented in software to simplify the development process, and a non-application-specific part, implemented in hardware as a parameterisable ‘black box’ module (i.e. IP core) to increase performance. Simulation results demonstrating a possible nanosatellite application of the design are presented; implementation (synthesis, timing, power) details are also presented.

ACS Style

Jeremy Soh; Xiaofeng Wu. A Scalable, FPGA-Based Implementation of the Unscented Kalman Filter. Introduction and Implementations of the Kalman Filter 2019, 1 .

AMA Style

Jeremy Soh, Xiaofeng Wu. A Scalable, FPGA-Based Implementation of the Unscented Kalman Filter. Introduction and Implementations of the Kalman Filter. 2019; ():1.

Chicago/Turabian Style

Jeremy Soh; Xiaofeng Wu. 2019. "A Scalable, FPGA-Based Implementation of the Unscented Kalman Filter." Introduction and Implementations of the Kalman Filter , no. : 1.

Journal article
Published: 11 February 2019 in Sensors
Reads 0
Downloads 0

In this paper, a bi-level Delta-Sigma modulator-based MEMS gyroscope design is presented based on a Model Predictive Control (MPC) approach. The MPC is popular because of its capability of handling hard constraints. In this work, we propose to combine the 1-bit nature of the bi-level Delta-Sigma modulator output with the MPC to develop a 1-bit processing-based MPC (OBMPC). This paper will focus on the affine relationship between the 1-bit feedback and the in-loop MPC controller, as this can potentially remove the multipliers from the controller. In doing so, the computational requirement of the MPC control is significantly alleviated, which makes the 1-bit MEMS Gyroscope feasible for implementation. In addition, a stable constrained MPC is designed, so that the input will not overload the quantizer while maintaining a higher Signal-to-Noise Ratio (SNR).

ACS Style

Xiaofeng Wu; Zhicheng Xie; Xueliang Bai; Trevor Kwan. Design of a 1-Bit MEMS Gyroscope Using the Model Predictive Control Approach. Sensors 2019, 19, 730 .

AMA Style

Xiaofeng Wu, Zhicheng Xie, Xueliang Bai, Trevor Kwan. Design of a 1-Bit MEMS Gyroscope Using the Model Predictive Control Approach. Sensors. 2019; 19 (3):730.

Chicago/Turabian Style

Xiaofeng Wu; Zhicheng Xie; Xueliang Bai; Trevor Kwan. 2019. "Design of a 1-Bit MEMS Gyroscope Using the Model Predictive Control Approach." Sensors 19, no. 3: 730.

Journal article
Published: 09 October 2018 in International Journal of Hydrogen Energy
Reads 0
Downloads 0

Although FC based electric buses are currently popular on urban streets or in short transit routes within large facilities, the version that is designed to operate on a highway, which has much higher dynamic requirements, is yet to be well developed. This research proposes to adopt the NSGA-II based multi-objective optimization scheme to optimize a fuel cell-battery-supercapacitor (SC) based FC power system (FCPS) that is specifically for a FC electric bus operating on the highway fuel economy cycle (HWFET). The optimization objectives are to minimize the FC's fuel consumption, the required battery and SC size and the battery degradation rate. More importantly, the optimization scheme is based on a combined energy management strategy (EMS) software parameter and hardware component sizing approach which is important for guaranteeing dynamically stable responses. This characteristic is achieved by imposing constraints that limit the transient time responses the DC-Bus capacitor voltage electrical parameters upon a generic step change in load power. Results demonstrate that dynamic stability can be guaranteed with proper software parameter and hardware components combinations without any trade-off requirements with the optimizer objectives. Moreover, the system mass and the battery degradation objectives are in trade-off but don't have any dependence to hydrogen consumption.

ACS Style

Trevor Hocksun Kwan; Xiaofeng Wu; Qinghe Yao. Parameter sizing and stability analysis of a highway fuel cell electric bus power system using a multi-objective optimization approach. International Journal of Hydrogen Energy 2018, 43, 20976 -20992.

AMA Style

Trevor Hocksun Kwan, Xiaofeng Wu, Qinghe Yao. Parameter sizing and stability analysis of a highway fuel cell electric bus power system using a multi-objective optimization approach. International Journal of Hydrogen Energy. 2018; 43 (45):20976-20992.

Chicago/Turabian Style

Trevor Hocksun Kwan; Xiaofeng Wu; Qinghe Yao. 2018. "Parameter sizing and stability analysis of a highway fuel cell electric bus power system using a multi-objective optimization approach." International Journal of Hydrogen Energy 43, no. 45: 20976-20992.

Journal article
Published: 01 September 2018 in Energy
Reads 0
Downloads 0

The thermoelectric (TE) device enables a conversion interface between the heat transfer and the electricity domain. Heat can be converted to electricity via the thermoelectric generator (TEG) effect and conversely, electricity can be converted to heat via the thermoelectric cooling (TEC) effect. In the meantime, varying the flow rate of coolants in a liquid cooling system is another common technique that is used to achieve temperature control. This paper proposes a fuzzy logic controller (FLC) that integrates both the combined TEG-TEC control method and the variable coolant rate techniques to achieve both the active temperature control (in TEC mode) and the energy harvesting capability (in TEG mode) of the TE device. The most significant control objectives are that the TEC mode is used to improve the temperature transient response whereas the variable coolant flow rate’s purpose is to drive the system towards operating in the TEG mode. Temperature control of a fuel cell stack is chosen as example study application and an experimental verification involving a heat emulator is presented to highlight the positive influence of the variable flow rate technique for improving the temperature transient and increasing the energy harvesting capability of the TEG-TEC control technique.

ACS Style

Trevor Hocksun Kwan; Xiaofeng Wu; Qinghe Yao. Integrated TEG-TEC and variable coolant flow rate controller for temperature control and energy harvesting. Energy 2018, 159, 448 -456.

AMA Style

Trevor Hocksun Kwan, Xiaofeng Wu, Qinghe Yao. Integrated TEG-TEC and variable coolant flow rate controller for temperature control and energy harvesting. Energy. 2018; 159 ():448-456.

Chicago/Turabian Style

Trevor Hocksun Kwan; Xiaofeng Wu; Qinghe Yao. 2018. "Integrated TEG-TEC and variable coolant flow rate controller for temperature control and energy harvesting." Energy 159, no. : 448-456.

Erratum
Published: 04 July 2018 in Energy Conversion and Management
Reads 0
Downloads 0
ACS Style

Trevor Hocksun Kwan; Xiaofeng Wu; Qinghe Yao. Erratum to “Thermoelectric device multi-objective optimization using a simultaneous TEG and TEC characterization” [Energy Convers. Manage. 168 (2018) 85–97]. Energy Conversion and Management 2018, 172, 645 .

AMA Style

Trevor Hocksun Kwan, Xiaofeng Wu, Qinghe Yao. Erratum to “Thermoelectric device multi-objective optimization using a simultaneous TEG and TEC characterization” [Energy Convers. Manage. 168 (2018) 85–97]. Energy Conversion and Management. 2018; 172 ():645.

Chicago/Turabian Style

Trevor Hocksun Kwan; Xiaofeng Wu; Qinghe Yao. 2018. "Erratum to “Thermoelectric device multi-objective optimization using a simultaneous TEG and TEC characterization” [Energy Convers. Manage. 168 (2018) 85–97]." Energy Conversion and Management 172, no. : 645.

Journal article
Published: 01 July 2018 in Energy Conversion and Management
Reads 0
Downloads 0
ACS Style

Trevor Hocksun Kwan; Xiaofeng Wu; Qinghe Yao. Thermoelectric device multi-objective optimization using a simultaneous TEG and TEC characterization. Energy Conversion and Management 2018, 168, 85 -97.

AMA Style

Trevor Hocksun Kwan, Xiaofeng Wu, Qinghe Yao. Thermoelectric device multi-objective optimization using a simultaneous TEG and TEC characterization. Energy Conversion and Management. 2018; 168 ():85-97.

Chicago/Turabian Style

Trevor Hocksun Kwan; Xiaofeng Wu; Qinghe Yao. 2018. "Thermoelectric device multi-objective optimization using a simultaneous TEG and TEC characterization." Energy Conversion and Management 168, no. : 85-97.

Journal article
Published: 24 April 2018 in Applied Energy
Reads 0
Downloads 0

The thermoelectric (TE) device enables a conversion interface between the heat transfer and the electricity domain. Specifically, it can operate bi-directionally – Heat can be converted to electricity via the thermoelectric generator (TEG) effect and vice versa via the thermoelectric cooling (TEC) effect. In most state of the art research, the TE device is operated either in the TEG mode or TEC mode but very seldom in both modes for a single control objective. This paper proposes a thermal management system for a fuel cell who exploits the bi-directional characteristics of the TE device to achieve both temperature control and the possibility for energy harvesting when active control is not required. The studied scenarios involve a time-based simulation involving heat generation levels that are typical of a 500 W rated operating proton exchange membrane fuel cell (PEMFC). The overall dynamic system is simulated using Simscape library components in Simulink and the controller itself is implemented using MATLAB s-functions. An experiment involving electric heaters to emulate the fuel cell’s body heat is also conducted to verify the proposed combined TEG-TEC control approach.

ACS Style

Trevor Hocksun Kwan; Xiaofeng Wu; Qinghe Yao. Bidirectional operation of the thermoelectric device for active temperature control of fuel cells. Applied Energy 2018, 222, 410 -422.

AMA Style

Trevor Hocksun Kwan, Xiaofeng Wu, Qinghe Yao. Bidirectional operation of the thermoelectric device for active temperature control of fuel cells. Applied Energy. 2018; 222 ():410-422.

Chicago/Turabian Style

Trevor Hocksun Kwan; Xiaofeng Wu; Qinghe Yao. 2018. "Bidirectional operation of the thermoelectric device for active temperature control of fuel cells." Applied Energy 222, no. : 410-422.

Journal article
Published: 28 February 2018 in Applied Energy
Reads 0
Downloads 0

As a clean power system with a narrow temperature range of typically 60–95 °C, the low temperature (LT) proton exchange membrane fuel cell (PEMFC) requires an effective thermal management system to enhance its efficiency and durability. This paper focuses on a genetic algorithm based optimization of the thermoelectric generator (TEG) as applied to the PEMFC system. The genetic algorithm approach is advantageous over similar previous research in that it enables multi-objective optimization where the various TEG module parameters can be configured towards critical objectives such as maximum output power, minimal mass and maintaining the PEMFC within its operating temperature range. A second case study is also studied where the combined efficiency of the PEMFC and TEG is selected as an objective in replacement of the maximum TEG output power. Optimization results suggest that, in both cases, there is a trade-off situation between maximum output TEG power or maximum system efficiency with respect to system mass. It is also shown that the most important benefit of increasing the cooling convection coefficient is that it increases the system’s specific power where the heat sink areas can be smaller to achieve the same cooling rate.

ACS Style

Trevor Hocksun Kwan; Xiaofeng Wu; Qinghe Yao. Multi-objective genetic optimization of the thermoelectric system for thermal management of proton exchange membrane fuel cells. Applied Energy 2018, 217, 314 -327.

AMA Style

Trevor Hocksun Kwan, Xiaofeng Wu, Qinghe Yao. Multi-objective genetic optimization of the thermoelectric system for thermal management of proton exchange membrane fuel cells. Applied Energy. 2018; 217 ():314-327.

Chicago/Turabian Style

Trevor Hocksun Kwan; Xiaofeng Wu; Qinghe Yao. 2018. "Multi-objective genetic optimization of the thermoelectric system for thermal management of proton exchange membrane fuel cells." Applied Energy 217, no. : 314-327.

Journal article
Published: 24 January 2018 in Review of Scientific Instruments
Reads 0
Downloads 0

This paper develops a drone control prototype based on web technology with the aid of hand gesture. The uplink control command and downlink data (e.g., video) are transmitted by WiFi communication, and all the information exchange is realized on web. The control command is translated from various predetermined hand gestures. Specifically, the hardware of this friendly interactive control system is composed by a quadrotor drone, a computer vision-based hand gesture sensor, and a cost-effective computer. The software is simplified as a web-based user interface program. Aided by natural hand gestures, this system significantly reduces the complexity of traditional human-computer interaction, making remote drone operation more intuitive. Meanwhile, a web-based automatic control mode is provided in addition to the hand gesture control mode. For both operation modes, no extra application program is needed to be installed on the computer. Experimental results demonstrate the effectiveness and efficiency of the proposed system, including control accuracy, operation latency, etc. This system can be used in many applications such as controlling a drone in global positioning system denied environment or by handlers without professional drone control knowledge since it is easy to get started.

ACS Style

Zhenfei Zhao; Hao Luo; Guang-Hua Song; Zhou Chen; Zhe-Ming Lu; Xiaofeng Wu. Web-based interactive drone control using hand gesture. Review of Scientific Instruments 2018, 89, 014707 .

AMA Style

Zhenfei Zhao, Hao Luo, Guang-Hua Song, Zhou Chen, Zhe-Ming Lu, Xiaofeng Wu. Web-based interactive drone control using hand gesture. Review of Scientific Instruments. 2018; 89 (1):014707.

Chicago/Turabian Style

Zhenfei Zhao; Hao Luo; Guang-Hua Song; Zhou Chen; Zhe-Ming Lu; Xiaofeng Wu. 2018. "Web-based interactive drone control using hand gesture." Review of Scientific Instruments 89, no. 1: 014707.