Advanced Materials Research Vol. 823

Abstract: With development of the short time interval measurement technology, array direction-finding technique for burst point localization has been applied to the actual. In this paper we conduct in the following order: the basic positioning principle will be elaborated at first. Then the precision estimation formula of the positioning will be deduced. Finally we perform the simulation experiment. The simulation results show that, if you want to improve the burst positioning accuracy, you need to decrease the measurement error of single station, and choose reasonable arrangement mode and the appropriate baseline length as far as possible.

Abstract: Measurement of the energy distribution of laser spots is an effective way in characterizing and diagnosing laser beam quality. After comparing conventional direct-detection and indirect-detection methods, a novel direct-detection scheme, which is based on detector-array controlled by single-chip microprocessors, is proposed. On the basis of analyzing key technologies such as data transmission and optical-electrical conversion, a block diagram of the system is proposed. In this system, a distributed structure was adopted which was composed of a host PC, a main microprocessor and lower microprocessors. This system is capable of measuring the parameters of laser beam in outfield such as size and shape of the spot, the energy of pulse and its distribution etc. It is suitable for most of lasers with repetition rate ranging from single pulse to several hundred per second and different energy up to moderate-high level. The system is more accurate than any former systems.

Abstract: This paper presents a hybrid GA-BP algorithm for fuzzy neural network controller (FNNC). BP algorithm is a method to monitor learning, easily realized and with good local searching ability. But it depends too much on the the initial states of the network. Genetic algorithm is a random search algorithm which has strong global searching ability. The hybrid GA-BP algorithm ensure the global convergence of learning by genetic algorithm, overcomes the BP algorithms dependency on the initial states on the one hand. On the other hand, combined with the BP algorithm overcome the simple genetic algorithms randomness, improve the searching efficiency. The simulations on the inverted pendulun problem show good performance and robustness of the proposed fuzzy neural network controller based on hybrid GA-BP algorithm.

Abstract: To solve the problem of constant power control of shearer cutting machine, the nonlinear predictive control method based on Neural Network was proposed in this thesis. In the method, the cutting current was used to identify the cutting load, and the Neural Network was used to predict and control the traction speed. A Neural Network model was built by the current and speed to control the cutting power of shearer. In MATLAB, the field data was used to simulate and the simulation verify the proposed scheme is better than PID method.

Abstract: The industrial robot is a typical electromechanical integration equipment constituted by operating machine, controller, servo drive system and the detection of sensing device. It is one of the most common industrial robots in the industrial field, which makes it work in almost any track or angle. This paper mainly presents the research on kinematics and trajectory planning for 6-DOF industrial robot. This study has finished the linear interpolation and arc interpolation in the Cartesian space. According to the advantages and disadvantages, this paper proposes the method of quadratic interpolation that meets the demands of 6-DOF industrial robot motion in the joints space and Cartesian space which ensures that the motion of 6-DOF industrial robot is smooth and stable.

Abstract: In hydraulic engineering, hydrology and water conservancy departments focus on the water level measurements of reservoir. Water level sensor is very important to water level measurements of reservoir. This paper designs a water level sensor which is combined with elastomeric membrane and fiber grating, to eliminate the impact of temperature on the sensor through the use of self-compensating fiber grating and structural technology. The measurement of the water level sensor in the range of 0-5m tests the characteristics of the sensor and concludes the experimental curves of wavelength drift caused by water level after temperature compensation. Experimental results show that the performance of the sensor is good, that the accuracy is 0.5%, and that the resolution is 1cm and linearity is 0.999. Keywords: water level monitoring, fiber grating, sensing measurements

Abstract: Performance test of infrared thermal imager is very significant for its working life and field maintenance, but available test equipment is huge volume, strict requirements for environment and user, high cost in use. According to the deficiency of field testing of infrared thermal imager performance, the method was put forward that using high precise temperature feedback controlled thermoelectric cooling module to instead expensive blackbody furnace. The techniques were adopted in the method such as infrared light signals simulation, optical-electric signals auto-detecting, image processing and the fusion of multi-detecting signals. The performance testing device of infrared thermal imager with low cost, convenient to field testing and maintenance was designed, the design broke the traditional model that the test of infrared thermal imager must be under the given condition, and the testing of electric and optical parameters should be separated. Keywords:infrared thermal imager; performance test; simulating infrared target; temperature feedback control

Abstract: With the development of microelectronics technology and microprocessor, some intelligent robots have emerged. This paper presents a simple design of the robot based on 51-series microcomputer and multiple sensors with the optimization algorithm.The fire-fighting robot which can avoid the obstacles with the photoelectric sensors, can extinguish fire through flame detection with far infrared sensors. The particle swarm optimization algorithm is introduced into software design to improve the sensitivity of fire-fighting robot,which has the advantages of simple structure and easy control.

Abstract: Communication is very common today, this document introduces a design of high frequency walkie-talkie for communication, and the design of the circuit is low power consumption. The circuit has transmitting circuit, receiving circuit, control circuit and so on, mainly includes mixer, filter, amplifier, frequency modulation (FM), demodulation, microcontroller unit (MCU), liquid crystal display (LCD), keymatrix and so on. This system not only can realise voice communication, but also can transmit short messages. Through the choice of ICs in the circuit, that makes the system to be a low power consumption system. So this system can be used in various conditions.

Abstract: OFDM is a special multi-carrier modulation, its basic idea is to make high-speed transmission of data flow through the serial-parallel conversion and make it to be the low-speed transmission of data flow in a number of narrow-band orthogonal sub-channels. However, a major drawback of OFDM signals is their high Peak-to-Average Power Ratio (PAPR), which makes the inter modulation distortion occur due to the nonlinearity of the high power amplifier. The distortion severely deteriorates the performance of the OFDM systems. According the problems mentioned above, this dissertation focuses on the reducing the PAPR algorithms design for OFDM systems, such as SLM and PTS. In summary, this paper has completed the OFDM system simulation with Matlab and analyses the result.