Distributed Event-triggered Consensus Control for Heterogeneous Multiagent Systems under Fixed and Switching Topologies

Junhua Huang,Liding Chen,Xuhuan Xie,Mufeng Wang,Bugong Xu 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.8

This paper investigates the distributed consensus problem for heterogeneous multi-agent systems via event-triggered scheme. To alleviate the communication burden, a distributed event-triggered consensus algorithm using an open-loo estimate and neighboring information is proposed. In the proposed event-triggered scheme, the control input of each agent is dependent on the estimate and information at discrete instants. Firstly, the novel event-triggered consensus algorithm is proposed for fixed topology, which involves the discrete communication between neighboring agents. Then, for the switching topology, the triggering condition is proposed by virtue of a topology-dependent dwell time approach. Further, the corresponding consensus procedures are given. Finally, the effectiveness of the proposed scheme is illustrated by numerical results.

Agri-environmental System Engineering and Energy : Original Article ; Emissions of Odor, Ammonia, Hydrogen Sulfide, and Volatile Organic Compounds from Shallow-Pit Pig Nursery Rooms

( Gopi Krishna Kafle ),( Lide Chen ) 한국농업기계학회 2014 바이오시스템공학 Vol.39 No.2

Purpose: The objective of this study was to measure emissions of gases (ammonia (NH3), hydrogen sulfide (H2S) and carbondioxide (CO2)), volatile organic compounds (VOC) and odor from two shallow pit pig nursery rooms. Gas and odor reductionpractices for swine operations based on the literature were also discussed. Methods: This study was conducted for 60 daysat a commercial swine nursery facility which consisted of four identical rooms with mechanical ventilations. Two rooms(room 1 (R1) and room 2 (R2)) with different pig numbers and ventilation rates were used in this study. The pig manurefrom both the R1 and R2 were characterized. Indoor/outdoor temperatures, ventilation rates/duration, NH3, H2S, CO2, andVOC concentrations of the ventilation air were measured periodically (3-5 times/week). Odor concentrations of theventilations were measured two times on two days. Three different types of gas and odor reduction practices (diet control,chemical method, and biological method) were discussed in this study. Results: The volatile solids to total solids ratio(VS/TS) and crude protein (CP) value of pig manure indicated the pig manure had high potential for gas and odor emissions. The NH3, H2S, CO2 and VOC concentrations were measured in the ranges of 1.0-13.3, 0.1-5.7, 1600-3000 and 0.0-1.83 ppm,respectively. The NH3 concentrations were found significantly higher than H2S concentrations for both rooms. The odorconcentrations were measured in the range of 2853-4432 OUE/m3. There was significant difference in odor concentrationsbetween the two rooms which was due to difference in pig numbers and ventilation duration. The literature studies showedthat simultaneous use of dietary control and biofiltration practices will be more effective and environmentally friendly forgas and odor reductions from pig barns. Conclusions: The gas and odor concentrations measured in the ventilation air fromthe pig rooms indicate an acute need for using gas and odor mitigation technologies. Adopting diet control and biofiltrationpractices simultaneously could be the best option for mitigating gas and odor emissions from pig barns.

Emissions of Odor, Ammonia, Hydrogen Sulfide, and Volatile Organic Compounds from Shallow-Pit Pig Nursery Rooms

Kafle, Gopi Krishna,Chen, Lide Korean Society for Agricultural Machinery 2014 바이오시스템공학 Vol.39 No.2

Purpose: The objective of this study was to measure emissions of gases (ammonia ($NH_3$), hydrogen sulfide ($H_2S$) and carbon dioxide ($CO_2$)), volatile organic compounds (VOC) and odor from two shallow pit pig nursery rooms. Gas and odor reduction practices for swine operations based on the literature were also discussed. Methods: This study was conducted for 60 days at a commercial swine nursery facility which consisted of four identical rooms with mechanical ventilations. Two rooms (room 1 (R1) and room 2 (R2)) with different pig numbers and ventilation rates were used in this study. The pig manure from both the R1 and R2 were characterized. Indoor/outdoor temperatures, ventilation rates/duration, $NH_3$, $H_2S$, $CO_2$, and VOC concentrations of the ventilation air were measured periodically (3-5 times/week). Odor concentrations of the ventilations were measured two times on two days. Three different types of gas and odor reduction practices (diet control, chemical method, and biological method) were discussed in this study. Results: The volatile solids to total solids ratio (VS/TS) and crude protein (CP) value of pig manure indicated the pig manure had high potential for gas and odor emissions. The $NH_3$, $H_2S$, $CO_2$ and VOC concentrations were measured in the ranges of 1.0-13.3, 0.1-5.7, 1600-3000 and 0.0-1.83 ppm, respectively. The $NH_3$ concentrations were found significantly higher than $H_2S$ concentrations for both rooms. The odor concentrations were measured in the range of $2853-4432OU_E/m^3$. There was significant difference in odor concentrations between the two rooms which was due to difference in pig numbers and ventilation duration. The literature studies showed that simultaneous use of dietary control and biofiltration practices will be more effective and environmentally friendly for gas and odor reductions from pig barns. Conclusions: The gas and odor concentrations measured in the ventilation air from the pig rooms indicate an acute need for using gas and odor mitigation technologies. Adopting diet control and biofiltration practices simultaneously could be the best option for mitigating gas and odor emissions from pig barns.

Reliability optimization design of hydraulic system considering oil contamination

Xinda Zhou,Zhaojun Yang,Hailong Tian,Chuanhai Chen,Liding Wang,Yongfu Zhu,Jia Liu 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.12

This paper presents a reliability optimization design method for a hydraulic system that considers oil contamination. The proposed method applies the quantitative relationship between oil contamination and system reliability to the reliability design of a hydraulic system, while considering the performance, layout, and other design factors. A global reliability model of the hydraulic system is constructed based on the oil contamination control model. Further studies aiming at an optimization design model of the hydraulic system is established where the cost is the objective function, reliability index, size and structure range, performance requirements are constraints, structure size and oil change period are design variables. For illustration, a case study on the reliability optimization design of the oil supply point branch of the static pressure bracket of a certain type of heavy CNC horizontal lathe is considered.

Anaerobic digestion of Chinese cabbage waste silage with swine manure for biogas production: batch and continuous study.

Kafle, Gopi Krishna,Bhattarai, Sujala,Kim, Sang Hun,Chen, Lide Taylor Francis ; Publications Division, Selper Ltd 2014 Environmental Technology Vol.35 No.21

<P>The aim of this study was to investigate the potential for anaerobic co-digestion of Chinese cabbage waste silage (CCWS) with swine manure (SM). Batch and continuous experiments were carried out under mesophilic anaerobic conditions (36-38C). The batch test evaluated the effect of CCWS co-digestion with SM (SM: CCWS=100:0; 25:75; 33:67; 0:100, % volatile solids (VS) basis). The continuous test evaluated the performance of a single stage completely stirred tank reactor with SM alone and with a mixture of SM and CCWS. Batch test results showed no significant difference in biogas yield up to 25-33% of CCWS; however, biogas yield was significantly decreased when CCWS contents in feed increased to 67% and 100%. When testing continuous digestion, the biogas yield at organic loading rate (OLR) of 2.0 g VSL?1 d?1 increased by 17% with a mixture of SM and CCWS (SM:CCWS=75:25) (423 mL g?1 VS) than with SM alone (361 mL g?1 VS). The continuous anaerobic digestion process (biogas production, pH, total volatile fatty acids (TVFA) and TVFA/total alkalinity ratios) was stable when co-digesting SM and CCWS (75:25) at OLR of 2.0 g VSL?1 d?1 and hydraulic retention time of 20 days under mesophilic conditions.</P>