Bendong Liu

A microsensor array for quantification of lubricant contaminants using a back propagation artificial neural network

We present a method based on an electrochemical sensor array and a back propagation artificial neural network for detection and quantification of four properties of lubrication oil, namely water (0, 500 ppm, 1000 ppm), total acid number (TAN) (13.1, 13.7, 14.4, 15.6 mg KOH g−1), soot (0, 1%, 2%, 3%) and sulfur content (1.3%, 1.37%, 1.44%, 1.51%). The sensor array, consisting of four micromachined electrochemical sensors, detects the four properties with overlapping sensitivities. A total set of 36 oil samples containing mixtures of water, soot, and sulfuric acid with different concentrations were prepared for testing. The sensor arrays responses were then divided to three sets: training sets (80% data), validation sets (10%) and testing sets (10%). Several back propagation artificial neural network architectures were trained with the training and validation sets; one architecture with four input neurons, 50 and 5 neurons in the first and second hidden layer, and four neurons in the output layer was selected. The selected neural network was then tested using the four sets of testing data (10%). Test results demonstrated that the developed artificial neural network is able to quantitatively determine the four lubrication properties (water, TAN, soot, and sulfur content) with a maximum prediction error of 18.8%, 6.0%, 6.7%, and 5.4%, respectively, indicting a good match between the target and predicted values. With the developed network, the sensor array could be potentially used for online lubricant oil condition monitoring.

The research of an energy recovery retarder with SRM structure

Most of the kinetic energy of car is transformed into heat with the traditional retarder. Then the heat is dissipating to the environment. A energy recovery retarder is introduced in this paper in order to overcome the shortcoming of the traditional retarder. The special single-phase switched reluctance motor is selected as the energy recovery retarder because of the launch of conditions. This solution has advantages such as large braking torque, simple structure, durable. The new retarder is easy to integrate with gearbox. it can adjust the speed of the first shaft of the gearbox. A single-phase switched reluctance motor for the retarder is designed in this paper. The theoretical calculation and simulation with Ansoft software is carried on. The calculation and simulation results show that the new retarder has energy recovery function.

Manipulation of micro-objects using acoustically oscillating bubbles based on the gas permeability of PDMS

This paper presents a novel manipulation method for micro-objects using acoustically oscillating bubbles with a controllable position based on the gas permeability of polydimethylsiloxane. The oscillating bubble trapped within the side channel attracts the neighboring micro-objects, and the position of the air-liquid interface is controlled by generating temporary pressure difference between the side channel and the air channel. To demonstrate the feasibility of the method in technological applications, polystyrene microparticles of 10u2009μm in diameter were successfully captured, transported, and released. The influence of pressure difference on the movement speed of the air-liquid interface was demonstrated in our experiments, and the manipulation performance was also characterized by varying the frequency of the acoustic excitation and the pressure difference. Since the bubble generation and the air-liquid interface movement in our manipulation method do not need any electrochemical reaction and any high temperature, this on-chip manipulation method provides a controllable, efficient, and noninvasive tool for handling micro-objects such as particles, cells, and other entities. The whole manipulation process, including capturing, transporting, and releasing of particles, spent less than 1 min. It can be used to select the cells and particles in the microfluidic device or change the cell culture medium.

Research on the Influence of Excitation Frequency on the Sensitivity in Metal Debris Detection with Inductor Sensor

The nonferromagnetic debris is easier to be detected as the excitation frequency increases; however, the sensitivity of ferromagnetic metal debris decreases as the excitation frequency increases. This paper is aimed at finding a range of excitation frequency that fit both ferromagnetic metal debris detection and nonferromagnetic metal debris detection. The equivalent circuit of the metal debris detection system with microinductor sensor is analyzed in this paper. The formulae of relationship between the sensitivity and excitation frequency are achieved according to the equivalent circuit. The simulation model of metal debris detection with the microsensor coil is built with the Ansoft software. The equivalent inductance and the electromagnetic induction field of the microinductor sensor are simulated as the excitation frequency changed. The experimental test is carried out with the prototype of microinductor sensor. The simulation results and the test results are compared. The studies indicate that the relationship between the excitation frequency and the changing rate of sensor inductance can be described by the fitting formulae. A higher sensitivity can be obtained if a suitable excitation frequency is selected. These researches have reference value for the design of inductor sensor and the parameters setting in the experimental test.

The control system research of paving machine for the modified asphalt coiled material

The modified asphalt coiled material is widely used as waterproofs in the construction of highway, railway and other engineering. The asphalt is usually paved by manual work. The quality of paving is easily affected by conditions such as the weather and the workers skill. However the working condition is very bad for the paving worker. It is necessary to research a paving machine in order to improve the paving quality and working conditions. A new paving machine for the modified asphalt coiled material is designed in this paper. Some anti-interference measures were adopted in order to adapt the bad environments. For example, PLC is used as the controller, AC servo motor and stepping motor is used as executive component. Photoelectrical coupling is used in circuit connection. This new paving machine two controls modes. One is manual control mode. The other is automatic mode. The worker controls the paving machine through operate the control panel in manual mode. The PLC control the direction and speed of the machine in the automatic mode with the photosensor seek the position of ground markers and send the signal to PLC. The proportional controlling means and the backlash compensation were adopted in this paper in order to achieve accuracy control. After numerous experiments, the paving machine can adapt to the construction requirements.