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The drive system provides power for high-speed motorized spindle which performance has a direct impact on the machining accuracy of numerical control (NC) machine tools. The motorized spindle drive system has a great influence on high precision computer numerical control (CNC) machine tools. This paper proposed a current hysteresis control design method based on the semi-physical simulation model for a motorized spindle driven system. The control system built-in Simulink could be packed and download to a digital signal processing (DSP) chip to verify the performance, which will save testing time and reduce development costs. A verification case was presented, and the results showed that the proposed semi-physical model was effective and could be used to accelerate the development of a driven system for motorized spindle.

Motorized spindle is a key functional component of machine tool. Its reliability and accuracy directly affect the operational reliability and machining accuracy of the entire CNC machine tool, and are even directly related to the production efficiency of the entire production line. The fault analysis of motorized spindle belongs to the category of reliability physics, and is the study of the fault phenomenon, mechanism, mode and hazard of motorized spindle. It is a necessary measure to realize the reliability growth of motorized spindle, and is a basic work ensuring the reliability of motorized spindle. The fault diagnosis of motorized spindle can provide a basis for subsequent reliability model establishment, reliability analysis and reliability design.

The thermal deformation of motorized spindle has a great influence on the precision of numerical control (NC) machine tools. Thus, it is crucial to predict the thermal deformation in the design and operation control phase by numerical simulation and improve the precision of NC machine tools. In order to achieve this, an accurate thermal deformation prediction model for motorized spindle is required. In this paper, a model for predicting the thermal error of motorized spindle based on finite element method and parameter optimization is proposed. Levenberg-Marquardt (LM) method is applied to optimize the heat transfer coefficient of motorized spindle by using surface temperature data measured. The optimized heat transfer coefficient is then taken as one of the boundary condition of the finite element model. The boundary conditions about heat of the finite element model are obtained by energy loss experiment. The proposed model is validated by experimental results, and the results have shown well correlation.

In this paper, a method for recognizing the crack location on the outer ring of the full ceramic bearing is proposed, which considers the transmission of the vibration signal on the outer ring when a crack occurs. A two-degree-of-freedom nonlinear dynamic model of the full ceramic bearing with a crack is established, and the impact of the crack is evaluated through the change of the strain energy. Then, considering the attenuation of the vibration signal along the outer ring, the dynamic model is improved with a time-varying stiffness related with the crack position. By analyzing the ratio of the synchronous root mean square difference of the vibration signal, the position of the outer ring crack is recognized. The simulation results are compared with the experimental results to verify the accuracy and feasibility of the position recognition method. The research provides a new recognition method for bearing fault location, and helps with the fault diagnosis and status monitoring of bearing systems.

This paper mainly focuses on the calculation and analysis on the radiation noise of the angular contact ball bearing applied to the ceramic motorized spindle. The dynamic model containing the main working conditions and structural parameters is established based on dynamic theory of rolling bearing. The sub-source decomposition method is introduced in for the calculation of the radiation noise of the bearing, and a comparative experiment is adopted to check the precision of the method. Then the comparison between the contribution of different components is carried out in frequency domain based on the sub-source decomposition method. The spectrum of radiation noise of different components under various rotation speeds are used as the basis of assessing the contribution of different eigenfrequencies on the radiation noise of the components, and the proportion of friction noise and impact noise is evaluated as well. The results of the research provide the theoretical basis for the calculation of bearing noise, and offers reference to the impact of different components on the radiation noise of the bearing under different rotation speed.

The positioning problem between the concrete distributor and the distributor area is one of the most important factor affecting the automatic distribution, in the production of precast concrete (PC) components. The detection system for the pre-calibration is designed based on photoelectric switch and encoder through in-depth analysis of concrete distribution technology in this paper. On this basis, considering the influence of reinforcing bars on the detection of magnetic-side-molds in the distribution area, the pre-calibration realization method of concrete distributor is designed by reasonably planning the traveling path of the distributor. This method can locate the pre-calibration point effectively, reduce the labor intensity of workers, and help to improve the automation level of the distributor.

Since a nonlinear relationship exists between the position coordinates of the rotation axes and components of the tool orientation, the tool will deviate from the required plane, resulting in nonlinear errors and deterioration of machining accuracy. Few attempts have been made to obtain a general formula and common rules for nonlinear error because of the existence of various kinematic structures of machine tools with orthogonal configuration. This paper analyzes the relationship between the deviation of cutter location points and motion of tool orientations. Five-axis CNC machine tools are divided into two groups according to the configuration of the two rotational joints and the home position. Motions of the tool are regarded as a combination of translation and rotation. A model for error calculation is then built. The maximum deviation of the tool with respect to the reference plane generated by the initial and the final orientation is used to quantify the magnitude of the errors. General formulas are derived and common change rules are analyzed. Finally, machining experiment is conducted to validate the theoretical analysis. The research has important implications on the selection of a particular kinematic configuration that may achieve higher accuracy for a specific machining task.

The spindle system of ordinary CNC lathe is a complex structure which could cause additional static, dynamic and heat loads during machining. In this study, a novel spindle system with shorten transmission link is used to reduce power consumption and improve machining performance. A series of models have been established for the spindle improvement, such as bearing forces, bending moment, and deflection of spindle. A comparison analysis on the machining characteristic of lathe with the two spindle systems is investigated. Improvements are presented mainly on machining efficiency and cutting capability. Finally, the improved shorten spindle system could substitute the ordinary spindle system for its high cutting efficiency and low cost.

The thermal characteristics of a motorized spindle are the main determinants of its performance, and influence the machining accuracy of computer numerical control machine tools. It is important to accurately predict the thermal field of a motorized spindle during its operation to improve its thermal characteristics. This paper proposes a model to predict the temperature field of a high-speed and high-precision motorized spindle under different working conditions using a finite element model and test data. The finite element model considers the influence of the parameters of the cooling system and the lubrication system, and that of environmental conditions on the coefficient of heat transfer based on test data for the surface temperature of the motorized spindle. A genetic algorithm is used to optimize the coefficient of heat transfer of the spindle, and its temperature field is predicted using a three-dimensional model that employs this optimal coefficient. A prediction model of the 170MD30 temperature field of the motorized spindle is created and simulation data for the temperature field are compared with the test data. The results show that when the speed of the spindle is 10,000 rpm, the relative mean prediction error is 1.5%, and when its speed is 15,000 rpm, the prediction error is 3.6%. Therefore, the proposed prediction model can predict the temperature field of the motorized spindle with high accuracy.

For the vertical and horizontal dual 5-axis system of a new turning-milling compound machining center, the dedicated post processor for 5-axis is developed by C++ programming language, B-axis pendulum angle error measurement technology and nonlinear error compensation algorithm are studied; and also analyzed and verified in actual processing; Researches show that: the dual 5-axis post processor works correctly and efficiently, better processing accuracy than 0.05mm can be obtained by nonlinear interpolation compensation for B-axis pendulum angle for 3 times, which meets the demand of crafts machining.

Vibration characteristic of mechanical system is the main factor affecting machine tool accuracy and longevity. The HTM50200 CNC with eight axles and double five-axis linkage was tested by a self-made vibration test system. The dynamic characteristic and fault diagnosis was analyzed by using the method of cepstrum identification on the vibration signal of X, Y, Z direction of the principal axis front. Analysis shows that the machining center has good dynamic characteristics, and has no obvious potential problems; the machining center is greatly influenced by Spindle cutter handle system; obtain the optimal processing parameters for machining center.

Solid Isotropic Microstructure with Penalization(SIMP) in topology optimization was deeply analyzed, and thus SIMP topology optimization criteria algorithm was deduced. Simulation analysis to the results was also conducted by Ansys, so as the structural lightweight design to machine crossbeams of the HTM series gantry. By verifying, the structure was 3.8% lower than the traditional structure quality, stiffness increased by 16.07%, and the overall inherent frequency was improved. By applying topology optimization method to the design process of the machining center HTM series, ma-terial utilization is improved and production costs were reduced.

It is pretty significant for fault diagnosis timely and accurately to improve the dependability of industrial processes. In this study, fault diagnosis of nonlinear and large-scale processes by variable-weighted kernel Fisher discriminant analysis KFDA based on improved biogeography-based optimisation IBBO is proposed, referred to as IBBO-KFDA, where IBBO is used to determine the parameters of variable-weighted KFDA, and variable-weighted KFDA is used to solve the multi-classification overlapping problem. The main contributions of this work are four-fold to further improve the performance of KFDA for fault diagnosis. First, a nonlinear fault diagnosis approach with variable-weighted KFDA is developed for maximising separation between the overlapping fault samples. Second, kernel parameters and features selection of variable-weighted KFDA are simultaneously optimised using IBBO. Finally, a single fitness function that combines erroneous diagnosis rate with feature cost is created, a novel mixed kernel function is introduced to improve the classification capability in the feature space and diagnosis accuracy of the IBBO-KFDA, and serves as the target function in the optimisation problem. Moreover, an IBBO approach is developed to obtain the better quality of solution and faster convergence speed. On the one hand, the proposed IBBO-KFDA method is first used on Tennessee Eastman process benchmark data sets to validate the feasibility and efficiency. On the other hand, IBBO-KFDA is applied to diagnose faults of automation gauge control system. Simulation results demonstrate that IBBO-KFDA can obtain better kernel parameters and feature vectors with a lower computing cost, higher diagnosis accuracy and a better real-time capacity.

Tooth wear is one of the main reasons that lead to gear failure. The amount of wear is nonlinearly related to temperature, lubrication, load, and various random factors of materials, with obvious randomness and slow time-varying characteristics. Wear is a nonstationary random process, which has no accurate mathematical model or accurate reliability estimation method. This article proposes a reliability model of spur gears which works under a nonstationary random process that exceeds the limit, and the time-varying wear reliability is studied based on the level crossing analysis method. The wear at tooth root is revised in the calculation under the nonstationary random process, and the reliability curves are obtained afterwards. An experiment is carried out on the spur gear meshing test rig, and the reliability model and wear performance are verified and analyzed. Results obtained with the proposed tooth surface wear reliability model match well with the experimental results. Therefore, this model is applicable for situations under a nonstationary random process. The new method makes contribution to the assessment of gear running status and is of great significance in the prediction of wear life under a nonstationary random process.

The thermal error of the motorized spindle has great influence on the accuracy of the NC machine tools. In order to reduce the thermal error, the increase type PID control algorithm is adopted for the control system which can make the temperature controlled in reasonable range. In accordance with the control object features, the Application of the control algorithm is realized in MCU System. Finally, the experiments are carried out which verified the validity and effectiveness of the design of temperature control system by analysis of the experimental data.

Keywords: mechanical spindle ; thermal analysis; temperature field;thermal balance time. Abstract:The article is based on precision CNC lathe spindle system of the 170CP06 as the research object.The steady and transient temperature field model of the mechanical spindle is established by using the finite element analysis method.As the heat rate for the load and the convective heat transfer coefficient for the boundary conditions for thermal analysis, the temperature field of spindle system is investigated to get the steady state temperature field distribution and thermal balance time of the spindle system.In order to verify the correctness of the model, the thermal experiments without load are executed to the key parts of the temperature of the spindle system at different speeds.Compared with the simulation results,it has a very good agreement with the reliability of the model.And it provides a theoretical basis for controlling the temperature rise of the spindle system.

Aiming at the problem that changes of nonlinear dynamic resistance of stator affect the performance of speed sensorless vector control system, a hybrid computing intelligence approach is used in the identification of stator resistance of motorized spindle. The partial least squares (PLS) regression is combined with neural network to solve the problem of few samples and multi-correlation of variables in complicated data modeling. The PLS method is used to extract variable components from sample data and then reduced the dimension of input variables. Moreover, neural network is used to fit the non-linearity between input and output variables. The model based on partial least squares regression and neural network can identify stator resistance under different conditions of the motorized spindle. The results show that the method has high identification precision and is helpful to improve the performance of vector control system.

Stone products' processing technologies, processes and types have essential differences with metal's, which makes the traditional machine design method can not perform well in the design of processing equipment for special shaped stones. A new design method was used in this paper, which through the establishment of stone typical products and tool mathematical model. The needs of the motion axes was solved by kinematics equations application and the feasible design scheme of the machine tool's function was established. Thus, a new turn-milling combined NC machine tools, which have 8 movement axis and Double 5 axis linkage processing function is designed. Its modular structure design can meet the needs of the most stone material processing. DOI: http://dx.doi.org/10.11591/telkomnika.v11i5.2560 Full Text: PDF

Aiming at the levelling precision, speed and stability of suspended access platform, this paper put forward a new adaptive fuzzy PID control levelling algorithm by fuzzy theory. The method is aided design by using the SIMULINK toolbox of MATLAB, and setting the membership function and the fuzzy-PID control rule. The levelling algorithm can real-time adjust the three parameters of PID according to the fuzzy rules due to the current state. It is experimented, which is verified the algorithm have better stability and dynamic performance. DOI: http://dx.doi.org/10.11591/telkomnika.v11i5.2563

Bending of a single-crystalline simply supported nano-beam is simulated with a molecular dynamics method. By changing the value of the span, the width and the depth of the cross section, and by varying the uniformly distributed load from 3.47 □10−4 to 11.6GPa, the results show that the span, the width, the depth and the uniformly distributed load all have effect on the vertical displacement (deflection) of the beam. When the load is beyond 0.0347GPa, the deflection increases and the deflection curve gets smoother as the load and the MD time step. When the load is less than 0.0347 GPa, the deflection has apparently no change with the increase of the load and the MD time step. The MD time step has little any effect on the horizontal displacement (along the width of the beam). The horizontal displacement decrease as the load increases. The span of the beam has little effect on the maximal deflection of the beam. The deflection decreases as the depth and width of the beam increasing. As the ratio of the surface area to the volume of the beam is decreasing, the deflection curve gets smoother with the exception of the depth whose value equates to 12a or 14a (a represents the lattice constant). When the ratio of the deflection to the horizontal displacement is beyond one unit, the uniformly distributed load plays a significant part in the bending deformation. However when the ration is within a unit, the horizontal deformation must be taken into account, which sometimes makes itself into a great deformation.

High speed and high precision are main research directions in modern mechanical manufacturing field; more and more parts are manufactured by high speed grinding. Effects of precision measurement instruments have obvious importance to realize zero waste manufacturing. This need to research test equipments for dynamic and quasi dynamic, even integrate with manufacturing equipments. The paper is on a new type measurement and control system using PMAC controller as a core of measurement and motion control, applied multithread technology of WIN32, multimedia timer and double buffer storage technology to realize to acquire from PMAC register and display real time. Solved real time data acquisition, mass storage and display, the experiments indicate cylindrical grinding machining and measurement realize integration.

Stone equipments develop for high speed and efficiency, intelligent, compound function direction. Analysis of machining center kinetic function was performed by sport theories. Finished special shaped stone compound machining center three-dimensional concept designing and projects selecting, realized stone turning function and carving and milling function to compound in a perpendicular slippery saddle first time. Kinetic simulation research on machining center was performed using COSMOSMotion, tracked spindle tool output displacement, speed and acceleration data by trajectory tracking, compared with mathematic model and tested correctness. The research indicated that machining range of machining center designed satisfied the requirements of machine.

Purpose: to study the performance of DTC system (direct torque control) within the Motorized Spindle full-speed range, and to improve the observation precision of Motorized Spindle stator flux by adopting the Full-order stator flux observer. Method: construct a Motorized Spindle DTC system based on the mathematical model of Motorized Spindle under a static stator reference frame; revise the deviation between status value and measured value of the Motorized Spindle, then build a Full-order magnetic flux observer with error-compensator based on close-loop state estimation by combining the feedback correction term and the mathematical model of Motorized Spindle with flux estimation; build a Full-order flux observer and simulate the Motorized Spindle DTC system by Matlab/Simulink so that the simulative waveform of stator flux would be obtained. Result: the correctness of Full-order stator flux observer at various speed ranges is verified. Conclusion: Full-order u-n stator flux observer shows satisfactory dynamic performance in Motorized Spindle DTC system; the u-n stator flux observer model that is constructed by choosing the proper way to set the pole of observer reduces the interference of temperature, frequency, magnetic path etc.

Study the prominent characteristics of ZigBee technology on wireless sensor networks, especially on the power consumption of the nodes. In order to reduce the power consumption of wireless sensor network node, this paper simulate the relation between the power consumption and the signal to noise ratio for the communications modulation, the relation between the power consumption and the transmission delay for the sleep mechanism, and the relation between the power consumption and the network throughput for MAC, by hardware structure and MAC protocols of the physical layer of the wireless sensor network node. And analyse the power consumption of the wireless sensor network node further. The modulation of PSK consumes the least power in all of the modulations of the wireless sensor network node obviously; the power consumption of EEMAC is the lowest in the MAC. The results show that the algorithm of EEMAC and the modulation of PSK are very compatible with the cooperations of many nodes. These results are very helpful to the structure optimization of the wireless sensor network node of ZigBee and the reducing of the power consumption of transfer data.