Advanced Materials Research Vols. 433-440

Abstract: In-wheel motor drive has been developed quickly. In this paper, the characteristics of four traditional machines are first reviewed and evaluated. Then, the present status of in-wheel motor drive are discussed, finally, future research trends of electrical machines in EVs are described.

Abstract: Aim to the three-level neutral-point potential balancing problem of three-level two stage matrix converter(TLTSMC),which is a new topology from matrix converter family that can synthesis three-level voltage in order to improve output performance in terms of reduced harmonic contents, this paper discussed the operating principles and a space vector modulation strategy with neutral-point potential balancing control for this topology. The method is divided into two control stages. Space vector PWM without zero vectors is used for rectifier stage. The modulation method of inverter stage based on the virtual space vector concept only requires the condition that the flow of neutral-point current equals zero, so the neutral-point balancing problem of this topology is effectively settled. The commutation principle of TLTSMC is analyzed. Finally, the validity and feasibility of this modulation method is tested by simulation and experiment, the result indicates that TLTSMC with the modulation strategy produces better output performance in terms of reduced harmonic contents and is also able to maintain sinusoidal input currents, furthermore, guarantees the balancing of neutral-point potential over the full range of output voltage.

Abstract: Inertial navigation system’s position error and velocity error are accumulated over time, it certainly affect the end guidance accuracy of the air munitions. To solve this problem, the information which includes altitude angle, azimuth angle, their angle velocity and altitude provided by passive seeker and altimeter is used for amending INS error with UKF algorithm in end-guidance phase. Through computer simulation the feedback filter with altimeter is better than that without altimeter.

Abstract: An Extended Kalman Filter (EKF) based on the “current” statistical model is developed for detection of highly maneuvering target using missile-borne Pulse Doppler radar. The online recursive filtering algorithm was also developed to estimate the four dimensional variable: relative distance, velocity, azimuth and elevation angles. Identifying the mean acceleration of maneuvering targets real-timely while estimating the state could improve the tracking performance. Simulation results show that the “current” statistical model based on EKF filtering algorithm is adaptive to high target maneuvering.

Abstract: A constant power control system based on Serial communication between a programmable logical controller (PLC) and a converter is put forward for high efficiency of oilfield workover rigs and for simple operation and reliability. In the condition of different transformers’ capacity, this system makes the motor always be in constant power state automatically by selecting power limit values. Operators with different practices can make use of this system because of its manual function which meets the demand of humanized design. This system can be used in other lifting equipment whose operation mode is similar to workover rigs.

Abstract: An intelligent terminal of telemetering, remote control and remote signaling which was capable of all the system operation regarding distant data transmission and monitoring on mobile, was assembled through the application of microcontroller and industrial communication module. Various physical quantities of devices could be measured and text-message transmitted by the designed multi-sensor. a microcomputer control center monitoring all kinds of terminals could be set up. The design can be further applied in Internet of Things.

Abstract: Aiming at the service robots in the family and hospital environment, the architecture of the onboard computer software for service robots is designed based on behavior control. And by using the weighted synthesizing based multi-action fusion mechanism in the software, the service robot complex behavior control is better realized. Experiments and applications show that the software system has many merits such as friendly interface, stable performance, convenient usage, good expansibility, and better meets the requirements of the service robots to software system on onboard computer in the home, office and medical environment. In reality, it has some potential benefits for their applications in relative fields.

Abstract: The cooperative maintenance is carried out of China's electric power system, an important research topic, how to achieve wide-area collaboration maintenance decision is one of the forefront research tasks in the maintenance field. In order to solve the knowledge resource sharing and utilization in the plants maintenance field, on the basis of analyzing the current status and needs of the maintenance network, to achieve the object of swarm cooperative maintenance decision-making, we have established the collaborative maintenance decision system, is supported by multi-knowledge, multi-method, multi-resource, multi-information based on knowledge grid, and also have investigated the knowledge modeling approach. Resource nodes open mutually, share resource information and by the unified management and scheduling of the knowledge grid platform, coordination between each other, provide the necessary services for different power plants, manufacturers and research institutes. That is beneficial to enhancing the diagnosis standards and treatment ability of the maintenance decision system, reducing the diagnosis and maintenance costs, and improving the diagnosis efficiency.

Abstract: Inverted pendulum system is a nonlinear, coupling, multi-variable and unstable system. In this paper, Linear Quadratic Regulator (LQR) is used to achieve optimal control of single inverted pendulum. First, the state-space model of the system is created. Then state feedback gain is calculated by selecting suitable weight coefficient matrix. Because the inverted pendulum system exists all kinds of disturbs inevitably, the states have errors and the accuracy of control drops. So square root filter is used to estimate states on line before LQR. The simulation results show control effect has obvious improvement because of adopting square root filter.

Abstract: When we monitor running state of induction motor in field, the sensorless estimation of load torque and speed of induction motor has important significance, in this paper, a method to estimate load torque and speed of motor using adaptive extended kalman filter(AEKF) is presented, the covariance matrices of noises are estimated while the speed and load torque of induction motor are estimated using EKF in this method; this method solved the problem that the estimate results of EKF are affected greatly by the covariance matrices of noise, Simulation demonstrate that this method can get higher estimated accuracy.