Qing Liang Zeng

Research of Equipment Selection and Matching Expert System in Fully Mechanized Caving Face Based on Ontology

The technologies of expert system, ontology modeling and reasoning are studied and applied in this paper. A framework of ontology-based expert system for equipment selection and matching in fully mechanized caving face is built up. The OWL(Web Ontology Language) based equipment knowledge base is set up, and the redundant test is made in the protégé environment. The equipment selection and matching rules are built up by using SWRL(Semantic Web Rule Language). By using JAVA language, the output of equipment selection expert system is optimized based on the theory of Analytic Hierarchy Process. At last, the functions of the expert system are achieved under JESS(Java Expert System Shell) environment. Practical application shows that the equipments selected and matched by ontology-based expert system are more realistic.

Accounting Method of Intensity for Double Telescopie Props of Hydraulic Supports

This paper mainly analyses the force state for upper telescopie prop, down telescopie prop and cylinder of double-telescopie props for hydraulic supports. It builds up the mathematic model for accounting intensity of double-telescopie props, and presents the calculating method of accounting intensity for double-telescopie props.

Numerical Simulation for Heat Transfer Process of Clinching with Magnesium Alloys

The clinching process of magnesium alloys has a great potential of being high efficient joining method, but it is restricted by the limited formability of magnesium alloys at room temperature. To form acceptable joints without cracking, it is usually required to heat the parts to about 220°C. However, the pre-heating times of traditional forming method is more than 3 to 6 seconds, the application of clinching for magnesium alloys is restricted by the over long periods of heating time. A new joining process with a contoured die is introduced to offer great benefits, especially in pre-heating time. Then the heat transfer process is simulated with DEFORM-3D software. The results show that the pre-heating time reduced to less than 1 second. Thus it is efficient and reliable in joining of magnesium alloys parts.

Simulation Analysis for Hydraulic Clamping Force of Bidirectional Hydraulic Lock' Valve Spool Based on Fluent

Bidirectional hydraulic lock is a key component of hydraulic system of the truck crane[1]. By using Fluent software, this paper simulates and analyses the hydraulic clamping phenomenon, which happens in the truck crane outrigger bidirectional hydraulic locks spool in the case of taper exists, as well as the center lines of spool and valve sleeve are eccentric, and the effect of different kinds of pressure-equalizing grooves on hydraulic clamping force, then concludes that the number, the shape and the size of pressure-equalizing grooves, and whether pressure-equalizing grooves are concentric can take effect on clamping force, thus a new way is prompted to improve the structure of bidirectional hydraulic lock.

Multi-Objective Optimization Design for Cutting Head of Roadheader

Aiming at load fluctuations and energy consumption of cutting head, a novel optimization strategy is presented in this paper, which is making every pick loaded uniformly and keeping number of picks in cutting section constant at every moment. It also considers the coal compression-tension effect and the action of pick tilt angle to pick force. The mathematical model of multi-objective optimization design for pick arrangement parameters and motion parameters of cutting head is established firstly, and then the sequential quadratic programming method (SQP) is chosen to compile the program of optimization design. The optimization example shows that in the premise of outline dimensions of cutting head unchanged, the load torque fluctuation decreases for 92%, which reduces the torsional vibration of transmission system of roadheader effectively. The swing force fluctuation also decreases for 83%, which enhances the stability of swing feed. Although the mean value of cutting head’ load decreases a little, all the load peaks decline after optimization, which avoid the single pick overload. And, the specific energy consumption decreases for 21%, which improves the energy utilization of roadheader.

Intelligent Vacuum-Pumping Detection Device Base on STM32MCU

Large centrifugal water pumps are widely applied in various water-supply and drainage systems. The vacuum-pumping is pre-requisite for their start-up so that the intelligent vacuum-pumping detection device utilizing STM32F103 as the main controller was presented to realize the automatic control especially of unattended pumps. A differential pressure transducer was adopted to measure the vacuum degree in pump chamber. Afterwards, an electrical signal of corresponding value was output, and then entered the ADC of STM32F103 after conditioning. The threshold algorithm was introduced for the judgement whether vacuum-pumping had been accomplished. Actual applications indicated this detection device was feasible and reliable, and the judgement algorithm was simply implemented and performed well in practice.

Study on Cost Modeling Based on Feature Mapping Technology

This thesis presents and summarizes the theory of multi-domain feature mapping in details and provides a basis of the conversion from design domain features to cost domain feature. It studies the current cost modeling techniques based on cost feature, and describes the whole process of cost feature modeling. This thesis lays a foundation for cost estimation.

Research on Modeling and Reasoning Framework of Ontology-Based Equipment Selection and Matching Expert System in Fully Mechanized Caving Face

In this paper, ontology modeling language and reasoning engines are studied and applied, framework model of ontology-based expert system is built up, the model tree of classes and instances of fully mechanized caving used equipments is brought forward, OWL-based equipment knowledge base is created by using protégé tool, knowledge rules of mining equipments selection and matching are analyzed, and SWRL-based selection and matching rules are designed. Finally, the rule conversion and reasoning is realized in JESS environment.

Research on Digital Controls of Piston Pumps Based on Compound Control Using Feed-Forward and Feedback Controls

Taking the swash plate piston pump as the research plant, the paper introduces the composition of digital control system of variable pump first; Then the mathematical model of variable mechanism is established according to which the closed-loop flow control system and the power control system are worked out. Also, the paper shows the stability margin of the control system and analyzes some response indices to step command under Matlab simulation. Aiming at the shortage of the closed-loop control system, the paper gives an idea of an optimization design of the compound power control system based on both feed-forward and feedback control. Compared with the conventional closed-loop power control method, the compound one gets a 47.2% reduction in the adjusting time and a 38.2% decrease in the overshoot indicating that the adjusting process is obviously shortened and the disturbance effect effectively weakened.

Study of the Testing System for Roadheader Pump and Motor

For the performance testing demands of roadheader hydraulic components, a hydraulic system of multi-interface and high-precision sensors is built and the signal acquisition and processing system based on PLC and data acquisition card high speed acquisition module is established. A software system based on LabWindows/CVI is developed. High precision, reliability, stable and functional test system is built by using precise sensor technology, electro-hydraulic proportional control technology and automation instrument technology, and then the pump and motor performance tests is completed. The system can simulate the actual working conditions of the pump and motor, making the test results more accurate and credible.