Jianxiong Chen

• PhD
• Professor (Associate) at Fuzhou University

To enhance the excavator performance considering the digging force and boom lift force under typical working conditions, this paper aims to solve the complex multiobjective optimization of the excavator by proposing a new knowledge-based method. The digging force at multiple key points is utilized to characterize the excavator’s performance during...

To address the limitation of existing excavator optimization methods, which primarily focus on the force performance while neglecting energy consumption and fail to realize environmentally friendly and low-carbon designs, this paper proposes a new multi-objective collaborative optimization method for an excavator to reduce energy consumption during...

In the surface profile analysis, there are often a few observations that contain outliers. Due to the existence of outliers, the application of non-robust reconstruction algorithms for measurement data will become a huge problem because these methods are often sensitive to outliers and the approximation effectiveness will be greatly aggravated. In...

Surface reconstruction method plays an important role in many engineering fields. It is an imperative procedure to carry out surface reconstruction from measurement data in reverse engineering, which is complicated with the presence of outliers. To achieve better accuracy and robustness of reconstruction, an improved moving total least squares (MTL...

Measuring and evaluating the geometric error of a linear axis periodically, is an essential operation in the day-to-day usage of a machine tool. In this paper, a system consisting of a novel one-dimension probe and a ball array is developed to fast estimate the geometric error a linear axis from the ball center deviations in three dimensions. The p...

Response-surface-based design optimization has been commonly used in robust process design (RPD) to seek optimal process settings for minimizing the output variability around the target value. Recently, online RPD strategy has attracted increasing research interests as it is expected to provide a better performance than offline RPD by utilizing onl...

The sample machined with the polygonal path is a common feature in a micro laser-cutting machine. It brings a difficult problem in feedrate planning when the machining accuracy is limited to the scale of sub-micrometer. In this paper, the transition feedrate at the node point is determined by the dynamic capacity of a machine. Then, the jerk-limite...

To improve the intensity and reliability of the emission fluorescence spectrum signal of petroleum pollutant samples, we designed multiple microchannel sample pools to replace traditional sample pool with square section. First, the microchannel structure of the sample pool was designed. Second, we analyzed the pulse intensity distribution and laser...

The processing of an ultra-short pulse laser is widely discussed and used in the field of micro machining, especially for precision processing of the hard and brittle materials. Firstly, the ablation ability would reduce with the defocusing distance increase in theory. However, it was found that the microchannel ablation depth is not sensitive to t...

The reconstruction of the profile curve of damaged parts in the absence of an original technical drawing is an important process of part repair. Part damages are complicated and changeable. To reduce the material removal rate during repair and maintain a smooth and flawless profile curve after being repaired, a smoothing and reconstruction strategy...

Quality improvement in micro-manufacturing processes relies on empirical models. However, if an estimated model varies from the true model because of random errors in experiments, the resulting operating conditions may be located far from the true optimal operating conditions. Using the Pareto chart, which highlights the most important among a set...

The plasma brightness cannot be used as a direct indicator of ablation depth detection by femtosecond laser was experimentally demonstrated, which led to the difficulty of depth measurement in the maching process. The tests of microchannel milling on the silicon wafer were carried out in the micromachining center in order to obtain the influences o...

Material processing using ultra-short-pulse laser is widely used in the field of micromachining, especially for the precision processing of hard and brittle materials. This paper reports a theoretical and experimental study of the ablation characteristics of a silicon wafer under micromachining using a femtosecond laser. The ablation morphology of...

In this paper, a software-based geometric error compensation method using the machining method template is proposed to modify the long and complicated G-code file with multiple machining features. Firstly, an error model is established to evaluate the error distribution. Then, a new segmentation method is proposed to split the long multi-axis line...

In this paper, a prediction-correction scheme is proposed to online measure and regulate the milling depth of microchannel using an indicator of laser triggered plasma. Firstly, a prediction model, with respect to the laser fluence and feedrate, is established with several calibration tests using the least square fitting method. It is utilized to c...

In this paper, an on-machine error calibration method, covering error modeling and measurement, is proposed to evaluate and compensate the errors caused by the mechanical and optical system equipped in the micromachining center using the femtosecond laser. Through preliminary tests by dicing silicon wafer, it has revealed that the squareness, laser...

This paper proposes a comprehensive geometric error measurement and identification method for a tilt table equipped in a five-axis machine tool with two turntables using the double ballbar. Three positional errors of the socket, caused by both the volumetric error and linkage error of the tilt table, are measured in the sensitive directions with si...

Nd: YLF laser beam machining (LBM) process has a great potential to manufacture intricate shaped microproducts with its unique characteristics. Continuous improvement (CI) effort for LBM process is usually realised by response surface methodology, which is an important tool in Design of Six Sigma. However, when determining the optimal machining par...

In this paper, a new online method is proposed to measure and identify the spindle thermal error of the machining center. The method is firstly established by a comprehensive error identification model including geometric and thermal error. Then the multi-viewpoint modeling method based on stereo vision is adopted to obtain the solution of thermal...

The binding interaction of lovastatin with calf thymus DNA (ct-DNA) was studied using UV/Vis absorption spectroscopy, fluorescence emission spectroscopy, circular dichroism (CD), viscosity measurement and molecular docking methods. The experimental results showed that there was an obvious binding interaction of lovastatin with ct-DNA and the bindin...

As the geometric errors of motion axis can be equivalent to the differential movement, regarded as a differential operator based on its ideal position, a new modeling method for multi-axis CNC machines based on differential transform theory is proposed in this paper. First, the workpiece coordinates is selected to observe the errors of the tool pos...

In this paper, comprehensive geometric errors, including linkage errors and volumetric errors, of a rotary table are measured totally by employing a double ballbar and obtained by a two-step identification procedure. The derivations of the center of the ball installed on the table are measured in the error sensitive directions with newly developed...

This paper puts forward a new permanent magnet synchronous wind-power generation grid-connected system based on solid state transformer. The high frequency transformer is added into the power electronics converters to realize an electrical isolation between the rectifier and the inverter. The output voltage of the inverter can be 10 kV and the grid...

Impurity doping often alters or improves the properties of materials. In alumina, grain boundaries play a key role in deformation mechanisms, particularly in the phenomenon of grain boundary sliding during creep at high temperatures. We elucidated the atomic-scale structure in alumina grain boundaries and its relationship to the suppression of cree...

The electronic structure and bonding of a realistic model of an intergranular glassy film (IGF) was studied with multiple computational methods. The model has a Si-O-N glassy region sandwiched between crystalline basal planes of beta-Si3N4 and contains a total of 798 atoms. It was constructed with periodic boundary conditions via classical molecula...

Nanometer thin intergranular glassy films (IGFs) form in polycrystalline ceramics during sintering at high temperatures. The structure and properties of these IGFs are significantly changed by doping with rare earth elements. We have performed highly accurate large-scale ab initio calculations of the mechanical properties of both undoped and Yittri...