Publications by authors named "Zhiqiang Zuo"

14 Publications

  • Page 1 of 1

Rapid dynamic quantification of sulfide generation flux in spatially heterogeneous sediments of gravity sewers.

Water Res 2021 Sep 2;203:117494. Epub 2021 Aug 2.

State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address:

Compared with anaerobic pressure sewers, gravity sewers have much more complex operational conditions, such as anaerobic/aerobic spatial variations along variable structures of the pipe network. This greatly complicates the prediction of sulfide generation from spatially heterogeneous sewer sediments. This study proposes a novel quantitative approach for rapidly estimating the sulfide generation flux by understanding the sulfidogenic conversion under complex sewer conditions. Significant anaerobic/aerobic spatial variations were the most critical factor affecting the sulfide production in residential gravity sewers. The dynamic aeration-related process stimulated the growth of sulfide-oxidizing bacteria (SOB) in the surface zone, while the sulfidogenic and methanogenic zone moved into deeper layers. A detailed mechanism model incorporating dynamic alternative anaerobic/aerobic transformation was developed to predict apparent sulfide production, as well as the microscale spatial profiles of chemicals and microbial communities in sediments. The model was evaluated to establish a rapid quantitative approach that only depended on a few key parameters (e.g., flow velocity, pipe diameter, slope, mean hydraulic depth and sulfate concentration), which can provide an important basis for estimating different sulfide generation fluxes under various sewer factors. The identification of sulfide generation hotspots will greatly help determine how to economically control sulfide generation by chemical dosing or pipe structural modification.
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http://dx.doi.org/10.1016/j.watres.2021.117494DOI Listing
September 2021

Fixed-time ESO based fixed-time integral terminal sliding mode controller design for a missile.

ISA Trans 2021 Jul 13. Epub 2021 Jul 13.

College of Automation Engineering, Institute of Flight Control, Nanjing University of Aeronautics and Astronautics, Nanjing, 211106, China. Electronic address:

This paper studies a novel fixed-time extended state observer based fixed-time integral terminal sliding mode controller for partial integrated guidance and control design. Firstly, a class of arbitrary-order systems with fixed-time stability is proposed by utilizing homogeneous approach, whose upper bound of convergence time is given. Then, an arbitrary-order fixed-time integral terminal sliding mode control is designed based on the proposed arbitrary-order fixed-time stable system, which avoids the singular problem. Subsequently, this paper constructs a new fixed-time extended state observer to further actively compensate for the disturbance caused by unknown target acceleration. Finally, numerical simulations show the effectiveness of the proposed controller.
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http://dx.doi.org/10.1016/j.isatra.2021.06.039DOI Listing
July 2021

An Integrated Model-Based and Data-Driven Gap Metric Method for Fault Detection and Isolation.

IEEE Trans Cybern 2021 Jul 8;PP. Epub 2021 Jul 8.

This article proposes an integrated approach of model-based and data-driven gap metric fault detection and isolation in a stochastic framework. For actuator and sensor faults, an adaptive Kalman filter combining with the generalized likelihood ratio method is suggested. For component faults, especially incipient faults, the model-based scheme maybe not a good choice due to the existence of disturbances or noises. Hence, a novel data-driven gap metric strategy is presented. The design of the appropriate fault cluster center model and radius via the gap metric technique is put forward to enhance the isolability of the incipient faults. Numerical simulation results are given to demonstrate the effectiveness of the proposed fault detection and isolation algorithm.
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http://dx.doi.org/10.1109/TCYB.2021.3086193DOI Listing
July 2021

Networked Multiagent Systems: Antagonistic Interaction, Constraint, and Its Application.

IEEE Trans Neural Netw Learn Syst 2021 Feb 8;PP. Epub 2021 Feb 8.

In this article, we study the consensus problem in the framework of networked multiagent systems with constraint where there exists antagonistic information. A major difficulty is how to characterize the communication among the interacting agents in the presence of antagonistic information without resorting to the signed graph theory, which plays a central role in the Altafini model. It is shown that the proposed control protocol enables us to solve the consensus problem in a node-based viewpoint where both cooperative and antagonistic interactions coexist. Moreover, the proposed setup is further extended to the case of input saturation, leading to the semiglobal consensus. In addition, the consensus region associated with antagonistic information among participating individuals is also elaborated. Finally, the deduced theoretical results are applied to the task distribution problem via unmanned ground vehicles.
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http://dx.doi.org/10.1109/TNNLS.2021.3054128DOI Listing
February 2021

Study of free nitrous acid (FNA)-based elimination of sulfamethoxazole: Kinetics, transformation pathways, and toxicity assessment.

Water Res 2021 Feb 11;189:116629. Epub 2020 Nov 11.

State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China, 100084. Electronic address:

Free nitrous acid (FNA)-based applications have been broadly adopted in the development of novel wastewater management technologies, but a basic understanding of the effect of the chemical properties of FNA on the elimination of micropollutants is still lacking. This study aims to comprehensively evaluate FNA-based elimination of sulfamethoxazole (SMX), which is a typical species of sulphonamide antibiotics. Batch experiments were conducted under different influencing factors to investigate the antibiotics elimination processes. We found that FNA showed specific efficacy on sulphonamides characterized by sulfonamide and aniline functional groups, such as SMX. SMX degradation was affected by the initial SMX concentration, FNA concentration and solution pH and described by d[SMX]/dt=-0.29e[SMX][FNA]. The cationic forms of SMX were more reactive towards FNA-based active components. Sulfonamide bond (S-N or C-S bonds) cleavage, nitrosubstitution, deamination and radical oxidation were proposed to be the relevant transformation pathways. The FNA-based technique was not effective for diminishing toxicity, but this process could strongly control antibacterial activity.
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http://dx.doi.org/10.1016/j.watres.2020.116629DOI Listing
February 2021

Stabilization of non-smooth variable order switched nonlinear systems.

ISA Trans 2021 Apr 10;110:160-171. Epub 2020 Oct 10.

Tianjin Key Laboratory of Process Measurement and Control, School of Electrical and Information Engineering, Tianjin University, Tianjin, 300072, PR China. Electronic address:

The paper discusses the issue of global asymptotic stabilization for non-smooth variable order nonlinear switched systems with partial unstable modes. The existence and uniqueness of solution for the considered system is firstly verified by utilizing Gronwall-Bellman inequality and the inductive method. Then, a slow switching strategy is performed for the stable modes and the unstable modes are handled by a fast switching mechanism. Under the framework of Filippov differential inclusion, sufficient stabilization criteria are derived by applying the mode-dependent average dwell time and dwell time schemes. Finally, some objects in real life are introduced and a numerical simulation is offered to show the validity of the obtained results.
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http://dx.doi.org/10.1016/j.isatra.2020.10.005DOI Listing
April 2021

Control sulfide and methane production in sewers based on free ammonia inactivation.

Environ Int 2020 10 13;143:105928. Epub 2020 Jul 13.

State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address:

Emissions of hydrogen sulfide and methane are two of the major concerns in sewers, causing corrosion, odour and health problems. This study proposed a new free ammonia (FA)-based approach for controlling the biological production of sulfide and methane in sewers. This is based on the discovery that the FA contained in urine wastewater is strongly biocidal to anaerobic sewer biofilms. Long-term operation of two laboratory sewer reactors, with one being dosed with urine wastewater and the other being dosed with raw sewage as a control, revealed the effectiveness of the proposed FA approach. The results showed that dosing of real urine wastewater at FA concentration of 154 mg NH-N/L with exposure for 24 h immediately reduced over 80% sulfide and methane in the experimental sewer reactor, while the time for recovering 50% sulfide and methane production were 6 days and 28 days, respectively. It also showed that intermittent dosing with an interval time of 5-15 days reduced around 60% sulfide on average. As suggested by community analysis, the remaining sulfide might be produced by a sulfate-reducing bacterial genus Desulfobulbus. Collectively, urine is a part of municipal sewage, and thus separation and re-dosing of the urine wastewater into the sewer for sulfide and methane control should enable the minimization of operational costs and environmental impacts, compared with the previous dosing of chemicals.
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http://dx.doi.org/10.1016/j.envint.2020.105928DOI Listing
October 2020

Free nitrous acid-based suppression of sulfide production in sewer sediments: In-situ effect mechanism.

Sci Total Environ 2020 May 22;715:136871. Epub 2020 Jan 22.

State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address:

Sulfide production control in gravity sewer sediments is more complex and difficult due to the greater spatial complexity of biological processes as a result of the abundant microflora inside the sediments. In this study, a promising and cost-effective free nitrous acid (FNA)-based suppression strategy for sulfide production in sewer sediments was proposed. Novel in-situ measurement methods were implemented by incorporating the diffusive gradients in thin films (DGT) technique and high-resolution dialysis (HR-Peeper) with microbial characterization analysis along the vertical sediment profile to examine the effect mechanism of the FNA-based inhibition process on sulfide production in the sediments. The results revealed that the FNA-based exposure strategy could effectively suppress the sulfidogenic activity across the whole shallow active layer (approximately 0.5 cm below the surface) in the sediments. An initial high FNA concentration up to 2.5 mg HNO-N/L was required to maintain a critical inhibition level (24-h average concentration > 0.2 mg HNO-N/L) across the whole active sediment zone. The FNA concentration decreased sharply deeper than 0.5 cm with a significant pH increase, resulting in FNA inactivation only reducing the microbial live/total ratio and shifting the microbial community structure near the sediment surface. Maintaining a low pH is the critical factor for the FNA-based suppression strategy of the sulfidogenic activity in the shallow sediment zone.
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http://dx.doi.org/10.1016/j.scitotenv.2020.136871DOI Listing
May 2020

Double-Integrator Dynamics for Multiagent Systems With Antagonistic Reciprocity.

IEEE Trans Cybern 2020 Sep 18;50(9):4110-4120. Epub 2019 Sep 18.

This article is dedicated to the consensus problem for interacting agents of the double-integrator dynamics subject to antagonistic reciprocity, described by negative scalar parameters. To this end, we first show the existence of the weighted gains which play an essential role for solving the consensus problem. Then, we establish the relationship between the weighted gains and scalar parameters to guarantee that the underlying "Laplacian" matrix contains a simple zero eigenvalue and the remaining eigenvalues enjoy positive real parts. Based on the above analysis, we further proceed to solve the considered problem. A major difficulty is that the Laplacian matrices, associated with the position and velocity information, are entirely distinct from each other, leading to the failure of the conventional consensus method for the second-order dynamics. We derive some criteria involving the weighted gains, the scaling parameters, and the real/image parts of the Laplacian matrix of the interaction graph. Moreover, some special frameworks, which have been extensively studied in the literature, are also elaborated on. Compared with the Altafini's model, we do not need to redefine a new Laplacian matrix, and more important, the restriction on the digon sign-symmetry property is removed. It is worth mentioning that the proposed consensus algorithm cannot be deduced by the Altafini's model or its variants. Finally, a wheeled multirobot system is formulated to validate the efficiency of the theoretical results.
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http://dx.doi.org/10.1109/TCYB.2019.2939487DOI Listing
September 2020

Active Event-Triggered Control for Nonlinear Networked Control Systems With Communication Constraints.

IEEE Trans Cybern 2021 May 15;51(5):2409-2418. Epub 2021 Apr 15.

In this paper, a novel reference input and hysteresis quantizer-based active event-triggered control (RIHQAETC) scheme is proposed for nonlinear networked control systems with quantizer, networked induced delay, and packet dropout. Different from the traditional methods, such a design method is constructed involving the structure of the hysteresis quantizer. In view of the network induced delay and the potential packet dropout, our RIHQAETC method is designed to actively compensate the negative effects caused by these two issues. The corresponding coder and decoder are also excogitated on account of the potential packet dropout based on the proposed triggering mechanism. Furthermore, the transmission of the important triggering information can be ensured as well as the finite-gain L stability performance. It is demonstrated by an example that our RIHQAETC method presents a more balanced updating frequency between the plant and the controller output sides and reduces the number of total triggering.
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http://dx.doi.org/10.1109/TCYB.2019.2907619DOI Listing
May 2021

Predictions of the Influent and Operational Conditions for Partial Nitritation with a Model Incorporating pH Dynamics.

Environ Sci Technol 2018 06 22;52(11):6457-6465. Epub 2018 May 22.

State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment , Tsinghua University , Beijing , China , 100084.

Ammonium partial oxidation to nitrite (i.e., partial nitritation) is required in a two-stage autotrophic nitrogen removal system, to provide effluent suitable for the anammox reaction. This study aims to establish influent (ammonium and bicarbonate concentrations) and operational (dissolved oxygen (DO) concentration and solids retention time (SRT)) conditions that favor partial nitritation. This is achieved through extending the nitritation and nitratation models to predict pH variation as well as the effects of pH, free ammonia (NH), and free nitrous acid (HNO) on the two reactions. Experiments were performed on a lab-scale sequencing batch reactor (SBR) operated for over 500 days to provide dynamic data for the calibration of model parameters, particularly those related to the NH and HNO inhibition on nitrite-oxidizing bacteria (NOB). The influent ammonium (19-84 mM) and bicarbonate (23-72 mM) were varied, which led to dynamic ammonium, nitrite, and nitrate data suitable for model calibration and validation. The model was able to well-describe pH dynamics as well as the inhibitory effects of NH and HNO on NOB. Model-based scenario analysis was then undertaken to establish the joint regions of influent ammonium and bicarbonate concentrations and the operational DO, temperature, and SRT conditions that favor partial nitritation. The results provide support to the design and optimization of partial nitritation reactors.
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http://dx.doi.org/10.1021/acs.est.8b00202DOI Listing
June 2018

Quantizer-Based Triggered Control for Chaotic Synchronization With Information Constraints.

IEEE Trans Cybern 2018 Aug 29;48(8):2500-2508. Epub 2017 Aug 29.

This paper mainly focuses on synchronization of controlled drive-response systems under Lurie form through a limited channel. The main contribution of this paper is the quantizer-based triggered methodology proposed based on three coders. By exploring coder structure information and fusing quantization and trigger errors together, this strategy can reduce transmission burden while increase synchronization speed concurrently. And the final synchronization error can be bounded within a predetermined fixed value. According to the initial output of drive system, different coders are purposely designed. With the proposed trigger schemes, traditional binary coder with memory cannot achieve desired performance. Meanwhile, it is found that the static coder leads to satisfactory performance when initial drive system output is within limited region. Combining the advantages of the above two coders, a mixed coder is designed to overcome the shortcomings. Moreover, synchronization error and transmission bit rate are thoroughly discussed and Zeno behavior is radically prevented. Finally, simulations for two Chua's circuits are given to illustrate the validity of the proposed method.
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http://dx.doi.org/10.1109/TCYB.2017.2741103DOI Listing
August 2018

Nitrite production from urine for sulfide control in sewers.

Water Res 2017 10 23;122:447-454. Epub 2017 May 23.

State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China; Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia.

Most commonly used methods for sewer sulfide control involves dosing chemical agents to wastewater, which incurs high operational costs. Here, we propose and demonstrate a cost-effective and environmentally attractive approach to sewer sulfide control through urine separation and its subsequent conversion to nitrite prior to intermittent dosage to sewers. Urine collected from a male toilet urinal was fed to laboratory-scale sequencing batch reactors. The reactors stably converted roughly 50% of the nitrogen in urine to nitrite, with high abundance (at 17.46%) of known ammonia-oxidizing bacteria (AOB) of the genus Nitrosomonas, and absence (below detection level) of typical nitrite-oxidizing bacteria of the genus Nitrospira, according to 454 pyrosequencing analysis. The stable nitrite production was achieved at both relatively high (1.0-2.0 mg/L) and low (0.2-0.3 mg/L) dissolved oxygen concentrations. Dosing tests in laboratory-scale sewer systems confirmed the sulfide control effectiveness of free nitrous acid generated from urine. Life cycle assessment indicated that, compared with commodity chemicals, nitrite/free nitrous acid (FNA) production from urine for sulfide control in sewers would lower the operational costs by approximately 2/3 and greenhouse gas (GHG) emissions by 1/3 in 20 years.
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http://dx.doi.org/10.1016/j.watres.2017.05.048DOI Listing
October 2017

A new method for stability analysis of recurrent neural networks with interval time-varying delay.

IEEE Trans Neural Netw 2010 Feb 18;21(2):339-44. Epub 2009 Dec 18.

Tianjin Key Laboratory of Process Measurement and Control, School of Electrical Engineering and Automation, Tianjin University, Tianjin, China.

This brief deals with the problem of stability analysis for a class of recurrent neural networks (RNNs) with a time-varying delay in a range. Both delay-independent and delay-dependent conditions are derived. For the former, an augmented Lyapunov functional is constructed and the derivative of the state is retained. Since the obtained criterion realizes the decoupling of the Lyapunov function matrix and the coefficient matrix of the neural networks, it can be easily extended to handle neural networks with polytopic uncertainties. For the latter, a new type of delay-range-dependent condition is proposed using the free-weighting matrix technique to obtain a tighter upper bound on the derivative of the Lyapunov-Krasovskii functional. Two examples are given to illustrate the effectiveness and the reduced conservatism of the proposed results.
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http://dx.doi.org/10.1109/TNN.2009.2037893DOI Listing
February 2010
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