The Experts below are selected from a list of 4149 Experts worldwide ranked by ideXlab platform
Zhenwei LIANG - One of the best experts on this subject based on the ideXlab platform.
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optimisation of a multi duct cleaning device for rice Combine Harvesters utilising cfd and experiments
Biosystems Engineering, 2020Co-Authors: Zhenwei LIANG, Josse De Baerdemaeker, Wouter SaeysAbstract:As the grain-cleaning process in a Combine harvester relies on pneumatic separation of the grain and chaff, the aerodynamic forces created by the airflow have a large impact on the cleaning performance. Therefore, to optimise a multi-duct cleaning device in a rice Combine harvester, First, the equivalent resistances for the different fan ducts were quantified with a resistance model of fluidised grain and an airflow resistance model for the cleaning sieve. Perforated plates with different opening ratios were designed to simulate working loads. A computational fluid dynamics (CFD) model was validated by comparing simulation results with hot-wire anemometer measurements. The effects of working loads on airflow velocity and volume distribution at the ducts, and total pressure distribution inside the fan were studied in simulation and experiments. After integration of the designed multi-duct fan into the cleaning system, airflow measurements inside the cleaning shoe were made and cleaning performance tests were carried out on a test bench. The ideal airflow velocity within the cleaning shoe was investigated by correlating airflow velocities at different measuring points and analysing the cleaning performance. An evaluation of this multi-duct cleaning system in the field showed large improvements in terms of the grain sieve losses ratio and grain impurity ratio compared to a Combine harvester with the single-duct cleaning system. The corresponding grain sieve loss decreased from 2.46% to 0.08%, while the grain impurity ratio decreased from 4.78% to 0.511%.
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numerical simulation of gas solid two phase flow to predict the cleaning performance of rice Combine Harvesters
Biosystems Engineering, 2020Co-Authors: Xiaoyu Chai, Guimin Wang, Zhenwei LIANGAbstract:To predict the cleaning performance of rice Combine Harvesters, numerical simulations of the air-and-screen cleaning unit using coupled computational fluid dynamics and discrete element method were used to study the gas–solid two-phase flow behaviour of the threshed mixture. The calculation methods investigated the centroid velocities of three particle classes: grains, stems and light impurities, and the degree of dispersion of all particles. It was found that the centroid velocity of the grain particles was the least affected by different working conditions at the same cleaning time, and the movement of grain particles did not reflect the varying cleaning performances. The degree of dispersion of all particles at each working condition reached a relatively stable state with cleaning times 1.3 s–2.0 s, and this period was taken as the analysis period. Cleaning performance experiments were carried out on the developed air-and-screen cleaning test-bed under corresponding conditions. The mathematical relationships between the centroid velocity of each particle class, the degrees of dispersion of all particles and the cleaning performance were studied. After comparison and analysis, it was concluded that the prediction model between the degree of dispersion of all particles and the cleaning loss ratio had an error less than 9.4%. The centroid velocity of short stem particles in X direction and the grain impurity ratio had an error less than 11.7%. This simulation method therefore had relatively good accuracy and can be used make up for the shortcomings caused by the seasonality of field testing and also save costs in designing cleaning units.
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development and testing of a multi duct cleaning device for tangential longitudinal flow rice Combine Harvesters
Biosystems Engineering, 2019Co-Authors: Zhenwei LIANG, Josse De Baerdemaeker, Wouter SaeysAbstract:Rice is one of the most important grain crops in China and most of these fields are harvested by Combine Harvesters. With increasing rice grain yields and feed rates, the cleaning systems rice Combine Harvesters have to deal with larger volumes of threshed output. Field experiments have shown that the standard single-duct cleaning systems used in most rice Combine Harvesters has become a limiting factor, resulting in high grain losses and producing high grain impurity ratios. To investigate the reasons for poor cleaning performance, the terminal velocity of the different categories of threshed outputs were quantified and turbine flow meter measurements were performed to obtain insights into the airflow distribution inside the cleaning shoe. Based on these insights, a multi-duct cleaning device with return pan was proposed for tangential-longitudinal-flow rice Combine Harvesters. The new cleaning system was benchmarked against a commercial system during parallel field tests and it was concluded that the design adaptations improved the sieve losses by 85% and the grain impurity ration by 73%.
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Grain Sieve Loss Fuzzy Control System in Rice Combine Harvesters
MDPI AG, 2018Co-Authors: Zhenwei LIANGAbstract:The main working parts of the cleaning device of a rice Combine harvester can be controlled by an established control strategy in real time based on the monitored grain sieve loss. This is an efficient way to improve their cleaning adaptability, since as a consequence, the main working parameters of Combine Harvesters can automatically adapt to crop and environment changes, and the corresponding cleaning performance can be improved. To achieve the target of cleaning control based on the monitored grain sieve loss, a fuzzy control system was developed, which selected S7-1200 PLC as the main control unit to build the lower computer hardware system, utilized ladder language to complete the system compilation, and used LabVIEW 14.0 software to design the host–computer interface. The effects of fan speed, guide plate angle, and sieve opening on the grain sieve loss and grain impurity ratio have been investigated through a large number of bench tests. The relevance level of the operating parameters on the performance parameters has been determined also, and finally, a fuzzy control model was developed for the cleaning system. The experiment results indicated that the designed fuzzy control model can control the cleaning section settings, such as fan speed and guide plate angle automatically, and reduce the grain sieve loss to some extent
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Sensor for monitoring rice grain sieve losses in Combine Harvesters
Biosystems Engineering, 2016Co-Authors: Zhenwei LIANG, Lizhang Xu, Yaoming Li, Zhan ZhaoAbstract:Grain sieve losses are important parameters to judge the performance of cleaning shoes in Combine Harvesters. To keep grain sieve loss within acceptable limits, an impact-type piezoelectric sensor was developed for real-time monitoring. Rice grain and short straw particle models were established according to their physical properties, and discrete element method (DEM) simulations were carried out to understand their collision behaviour with the sensor. The influence of grain shape, straw length and impact angle on variations of the maximum normal contact force and force rise-time were analysed in detail. Differences in normal collision force, and force rise-time occurred which lead to corresponding differences in signal frequency and voltage amplitude. A signal processing circuit, which mainly consisted of a band-pass filter circuit and a voltage comparator circuit, was designed to discriminate for full grains. Field tests results indicated that measurement errors recorded by the sensor and checked against manually measurements were
Zhan Zhao - One of the best experts on this subject based on the ideXlab platform.
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Sensor for monitoring rice grain sieve losses in Combine Harvesters
Biosystems Engineering, 2016Co-Authors: Zhenwei LIANG, Lizhang Xu, Yaoming Li, Zhan ZhaoAbstract:Grain sieve losses are important parameters to judge the performance of cleaning shoes in Combine Harvesters. To keep grain sieve loss within acceptable limits, an impact-type piezoelectric sensor was developed for real-time monitoring. Rice grain and short straw particle models were established according to their physical properties, and discrete element method (DEM) simulations were carried out to understand their collision behaviour with the sensor. The influence of grain shape, straw length and impact angle on variations of the maximum normal contact force and force rise-time were analysed in detail. Differences in normal collision force, and force rise-time occurred which lead to corresponding differences in signal frequency and voltage amplitude. A signal processing circuit, which mainly consisted of a band-pass filter circuit and a voltage comparator circuit, was designed to discriminate for full grains. Field tests results indicated that measurement errors recorded by the sensor and checked against manually measurements were
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structure optimization of a grain impact piezoelectric sensor and its application for monitoring separation losses on tangential axial Combine Harvesters
Sensors, 2015Co-Authors: Zhenwei LIANG, Zhan ZhaoAbstract:Grain separation losses is a key parameter to weigh the performance of Combine Harvesters, and also a dominant factor for automatically adjusting their major working parameters. The traditional separation losses monitoring method mainly rely on manual efforts, which require a high labor intensity. With recent advancements in sensor technology, electronics and computational processing power, this paper presents an indirect method for monitoring grain separation losses in tangential-axial Combine Harvesters in real-time. Firstly, we developed a mathematical monitoring model based on detailed comparative data analysis of different feeding quantities. Then, we developed a grain impact piezoelectric sensor utilizing a YT-5 piezoelectric ceramic as the sensing element, and a signal process circuit designed according to differences in voltage amplitude and rise time of collision signals. To improve the sensor performance, theoretical analysis was performed from a structural vibration point of view, and the optimal sensor structural has been selected. Grain collide experiments have shown that the sensor performance was greatly improved. Finally, we installed the sensor on a tangential-longitudinal axial Combine harvester, and grain separation losses monitoring experiments were carried out in North China, which results have shown that the monitoring method was feasible, and the biggest measurement relative error was 4.63% when harvesting rice.
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optimum design of grain impact sensor utilising polyvinylidene fluoride films and a floating raft damping structure
Biosystems Engineering, 2012Co-Authors: Zhan Zhao, Zhenwei LIANG, Yaoming Li, Yi ChenAbstract:Grain losses are unavoidable during harvesting. In order to improve the efficiency and reduce grain losses, the major structural and operational parameters of Combine Harvesters need to be adjusted accordingly. So, it is important to develop a sensor which can monitor the grain losses real-time. A sensor using piezoelectric polyvinylidene fluoride (PVDF) film as sensitive material for monitoring grain losses of Combine Harvesters is described. A floating raft damping structure was used to construct the sensor to suppress the influence of vibrations. Based on a dynamic analysis of sensor model, response properties of the sensor under working conditions were calculated. The results indicated that the amplitude and frequency of vibration interference were both decreased by optimising the isolators. A signal processing circuit composed of charge amplifier, high-pass filter, absolute value amplifier, envelope detector and voltage comparator in series was designed to detect grain impact signal. A square wave voltage signal was produced while grain impact was detected, and the mean time width was
Sheng Qiang - One of the best experts on this subject based on the ideXlab platform.
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The within-field and between-field dispersal of weedy rice by Combine Harvesters
Agronomy for Sustainable Development, 2018Co-Authors: Pinglei Gao, Zheng Zhang, Guojun Sun, Sheng QiangAbstract:AbstractWeedy rice (Oryza sativa L.) severely decreases the grain yield and profitability of rice is one of the most significant problems in the majority of rice fields worldwide. Few reports focus on the dispersal of weedy rice, especially how it rapidly spreads to large areas and long distances. Here, we quantify for the first time the within- and between-field dispersal of weedy rice associated with Combine harvesting operations. We randomly sampled 31 Combine Harvesters to determine where and how much weedy rice seeds remained on the machines at three locations in Jiangsu Province, China. Based on the sampling results, the field area over which weedy rice seeds were retained on the Combine harvester during harvesting was estimated to assess the within-field dispersibility of weedy rice seeds remaining in the Harvesters. A tracking experiment was also carried out by tracing the distribution of weedy rice seeds along harvest trails, to estimate the dispersal of weedy rice seeds within the field being harvested. Weedy rice seeds remained in the harvest pocket, on the pedrail, and the metal plate of the Combine harvester. On average, more than 5000 weedy rice seeds which were 22.80% of remaining grains could potentially be transported into adjacent fields by the Combine after each rice field infested with weedy rice had been harvested. Of the statistical models compared, a double exponential model simulating the variation in seed retention predicted that weedy rice seeds remaining on the metal plate could be dispersed over 6473.91 m2 or 3236.96 m into the next field during the harvesting operation. Within the field, the number of fallen weedy rice seeds and their dispersal distance were positively correlated to weedy rice panicle density with the Combine dispersing most of seeds away from their mother plant thus creating new weed patches. Therefore, fields that were severely infested with weedy rice should be harvested cautiously and separately and seed remaining in a harvester should be avoided to prevent intra- and inter-field, and even cross-regional dispersal of weedy rice.
Josse De Baerdemaeker - One of the best experts on this subject based on the ideXlab platform.
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optimisation of a multi duct cleaning device for rice Combine Harvesters utilising cfd and experiments
Biosystems Engineering, 2020Co-Authors: Zhenwei LIANG, Josse De Baerdemaeker, Wouter SaeysAbstract:As the grain-cleaning process in a Combine harvester relies on pneumatic separation of the grain and chaff, the aerodynamic forces created by the airflow have a large impact on the cleaning performance. Therefore, to optimise a multi-duct cleaning device in a rice Combine harvester, First, the equivalent resistances for the different fan ducts were quantified with a resistance model of fluidised grain and an airflow resistance model for the cleaning sieve. Perforated plates with different opening ratios were designed to simulate working loads. A computational fluid dynamics (CFD) model was validated by comparing simulation results with hot-wire anemometer measurements. The effects of working loads on airflow velocity and volume distribution at the ducts, and total pressure distribution inside the fan were studied in simulation and experiments. After integration of the designed multi-duct fan into the cleaning system, airflow measurements inside the cleaning shoe were made and cleaning performance tests were carried out on a test bench. The ideal airflow velocity within the cleaning shoe was investigated by correlating airflow velocities at different measuring points and analysing the cleaning performance. An evaluation of this multi-duct cleaning system in the field showed large improvements in terms of the grain sieve losses ratio and grain impurity ratio compared to a Combine harvester with the single-duct cleaning system. The corresponding grain sieve loss decreased from 2.46% to 0.08%, while the grain impurity ratio decreased from 4.78% to 0.511%.
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development and testing of a multi duct cleaning device for tangential longitudinal flow rice Combine Harvesters
Biosystems Engineering, 2019Co-Authors: Zhenwei LIANG, Josse De Baerdemaeker, Wouter SaeysAbstract:Rice is one of the most important grain crops in China and most of these fields are harvested by Combine Harvesters. With increasing rice grain yields and feed rates, the cleaning systems rice Combine Harvesters have to deal with larger volumes of threshed output. Field experiments have shown that the standard single-duct cleaning systems used in most rice Combine Harvesters has become a limiting factor, resulting in high grain losses and producing high grain impurity ratios. To investigate the reasons for poor cleaning performance, the terminal velocity of the different categories of threshed outputs were quantified and turbine flow meter measurements were performed to obtain insights into the airflow distribution inside the cleaning shoe. Based on these insights, a multi-duct cleaning device with return pan was proposed for tangential-longitudinal-flow rice Combine Harvesters. The new cleaning system was benchmarked against a commercial system during parallel field tests and it was concluded that the design adaptations improved the sieve losses by 85% and the grain impurity ration by 73%.
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Advanced control of Combine Harvesters
IFAC Proceedings Volumes (IFAC-PapersOnline), 2013Co-Authors: Josse De Baerdemaeker, Wouter SaeysAbstract:Combine Harvesters are complex agricultural machines to harvest different kinds of grain crops. There are now indications that a further increase in machine size may no longer be possible for reasons of soil compaction by the heavy loads and also because of access to public roads. It is expected that further increase in efficiency and productivity of the harvesting process can be obtained by controlling the whole harvesting process as well as all sub-processes online and, desirably, optimally. However, this makes it necessary to estimate certain machine efficiency indicators such as grain losses online. Model-based estimation techniques are suitable for this task. However, the method requires a mathematical model of the process as well as system-relevant measurements. Copyright © 2013 IFAC.
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Throughput control on a Combine harvester using Model-based Predictive Control
2010 Pittsburgh Pennsylvania June 20 - June 23 2010, 2010Co-Authors: T Coen, Josse De Baerdemaeker, Wouter SaeysAbstract:Since it is no longer possible to increase the size of Combine Harvesters, increasing the machine efficiency is the only way to further raise the capacity. The most straightforward way to do so is to make every operator behave as the optimal operator, and this 24/7. This paper presents on a control system that regulates the speed of the Combine harvester based on process variables such as feed rate, engine load and grain mass flow such that the capacity utilization is maximized at all times.
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identification of sensor faults on Combine Harvesters using intelligent methods
IFAC Proceedings Volumes, 2005Co-Authors: Geert Craessaerts, T Coen, Josse De BaerdemaekerAbstract:Abstract Process monitoring and fault diagnosis is of considerable interest from an industrial perspective. In this paper, the general applicability of intelligent methods, like self-organizing maps (SOM) and multilayer feedforward networks with backpropagation, for the identification of sensor failure on Combine Harvesters will be illustrated. Both neural network types showed comparable results in order to classify normal and faulty sensor conditions.
Pinglei Gao - One of the best experts on this subject based on the ideXlab platform.
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The within-field and between-field dispersal of weedy rice by Combine Harvesters
Agronomy for Sustainable Development, 2018Co-Authors: Pinglei Gao, Zheng Zhang, Guojun Sun, Sheng QiangAbstract:AbstractWeedy rice (Oryza sativa L.) severely decreases the grain yield and profitability of rice is one of the most significant problems in the majority of rice fields worldwide. Few reports focus on the dispersal of weedy rice, especially how it rapidly spreads to large areas and long distances. Here, we quantify for the first time the within- and between-field dispersal of weedy rice associated with Combine harvesting operations. We randomly sampled 31 Combine Harvesters to determine where and how much weedy rice seeds remained on the machines at three locations in Jiangsu Province, China. Based on the sampling results, the field area over which weedy rice seeds were retained on the Combine harvester during harvesting was estimated to assess the within-field dispersibility of weedy rice seeds remaining in the Harvesters. A tracking experiment was also carried out by tracing the distribution of weedy rice seeds along harvest trails, to estimate the dispersal of weedy rice seeds within the field being harvested. Weedy rice seeds remained in the harvest pocket, on the pedrail, and the metal plate of the Combine harvester. On average, more than 5000 weedy rice seeds which were 22.80% of remaining grains could potentially be transported into adjacent fields by the Combine after each rice field infested with weedy rice had been harvested. Of the statistical models compared, a double exponential model simulating the variation in seed retention predicted that weedy rice seeds remaining on the metal plate could be dispersed over 6473.91 m2 or 3236.96 m into the next field during the harvesting operation. Within the field, the number of fallen weedy rice seeds and their dispersal distance were positively correlated to weedy rice panicle density with the Combine dispersing most of seeds away from their mother plant thus creating new weed patches. Therefore, fields that were severely infested with weedy rice should be harvested cautiously and separately and seed remaining in a harvester should be avoided to prevent intra- and inter-field, and even cross-regional dispersal of weedy rice.