Advanced Materials Research Vols. 433-440

Abstract: To avoid the chattering disadvantage of sliding-mode control (SMC), in this paper, a quasi-sliding mode controller is proposed for real-time fine control of a nonholonomic mobile robot. First, the dynamics of mobile robot is analyzed by Lagrangian formula. Then, the quasi-sliding mode controller is used to generate the control torque that drives the mobile robot, such that the linear and angular velocities of the mobile robot follow the desired velocities. At last, computer simulation results confirm the effectives of SMC.

Abstract: When global positioning system (GPS) signal outages, the integrated navigation accuracy of GPS and strap-down inertial navigation system (SINS) will decline with time, and even navigation system cannot work. To avoid this, a new design is introduced. When GPS works normally, square root filter estimates the errors of position, velocity and attitude and compensates the outputs of SINS. When GPS is out of order, back propagation neural network (BPNN) will take the place of GPS to calculate the error parameters, thus the accuracy of navigation will enhance. And in this paper, the unit of fault detection is added to detect whether GPS signal outages or not. The simulation results show the effectiveness of this method

Abstract: Inverted pendulum system is a nonlinear, coupling, multi-variable and unstable system. Because the inverted pendulum system exists all kinds of disturbs inevitably, the states have errors and the accuracy of control drops. In this paper, quasi-sliding mode control is used to achieve optimal control. First, the state-space model of the system is created by force analysis. Then, in the design of the controller, we make use of the sliding mode control, which has the advantage of anti-interference. To reduce the chattering phenomenon, we utilize saturation function in the reaching low design. The simulation results show the effective of the method

Abstract: This paper proposes a method of vehicle occlusion detection and segment based on windows of the vehicle, which is used in high-definition (HD) video. Firstly, do the vehicle position after extract the background using the method of continuous frame differential method. Then draw brightness curve of the positioning region and set the threshold to segment the region of windows. From the number of windows we can judge whether vehicle occlusion is happen and do the next step. Experiments show that this method is simple and effective, with less computation, and it can divide occluded vehicles effectively, and satisfy the requirements of real-time processing.

Abstract: In this paper, a dynamics model basing on the BP algorithm is proposed. The algorithm that can enhance the performance of the adaptability is the combination of torque control and a compensation structure using ANN. Errors are inevitable while the modeling for dynamics of robot manipulator. But they can be compensated by the compensation structure of ANN. The result of simulation shows that the controller can get the performance of trajectory well and the structure of controller is feasible.

Abstract: In the area of manufacturing and industrial engineering, variance calculation is the basic method to monitor the performance of instrument. In this paper, the recursive formula of real-time variance calculation is been put forward. Then it is possible to calculate the variance at real time without save the historical data. Experiment results shows that the new method for calculate the variance can greatly improve the calculating efficiency with high precision.

Abstract: According to the characteristics of many varieties small batch production, the assembly workers with operating accurate, coordination and strong learning ability are needed in a manual assembly line. Some scientific operating skills test is used to evaluate staff in recruitment, working hours formulate and performance evaluation. The origins and definition of learning curve were introduced. The characteristics of operation skills were analyzed. The mirror painting instrument was used to test the learning ability of workers for new operation skills. Workers were asked to face the graphics within the mirror, and to depict the graphics using the testing pen. The mistake number and the operation time were recorded. Learning curves were drawn out. Everyone worker movement skills forming process was analyzed on the basis of the above data. The test process and analyze conclusion provide the scientific basis and the decision support for the enterprises.

Abstract: The demand of the economy of the modern car becomes higher and higher, and the lightening design of the vehicle is an important factor in improving the economy. We do the finite element analysis for the built 3d model of the off-road vehicle frame to obtain the stress distribution and the displacement distribution, which can be used as the basis for The Lightening Design of the off-road vehicle frame. On the premise of keeping the general function unchanged, we can achieve the goal of lightening the vehicle, and improving the economy.

Abstract: This paper proposes a vision-based embedded motion control system that is developed in our research group. The system is an integration of three subsystems including, an embedded positioning platform, a vision system for inspection and a crystal reorientation system. The system is used as a positioning platform and crystal reorientation system to automate the crystal reorientation process. This process is important in ensuring that the units are correctly oriented for production processes. The focus of this research is placed on how to develop the embedded positioning platform, the crystal reorientation system, and how to improve the system performances including positioning and reorientation accuracy in high speed operation and quality of inspection. A distributed control architecture has been developed using PIC18F4520 microcontrollers. Tests run on the complete system have shown that the system is capable of a minimum indexing time of 1.53 units per second and a reorientation time of 1.42 seconds.

Abstract: In this paper, a new and simple method for deriving the formulas of Relativity is introduced. Einstein derived the formulas of Relativity by applying two hypotheses about light velocity, but this process was rather complicated and hard to understand. Nuclear physics has been developing for nearly a hundred years and has accumulated plenty of experiment results. Now it is feasible to derive Einstein’s formulas by employing the experiment results of nuclear physics. According to the result that energy is an expression form of mass, E=m can be obtained. We differential the above formula, adopt several steps of simple mathematical calculation, a simple differential equation can be obtained. Take the result of “light velocity is the velocity limit of a moving object” as the boundary condition of the differential equation, we get energy formula and mass formula. Length formula and time formula can also be easily derived based on the experiment result of particle speed in a cyclotron. As all the formulas of Relativity in this paper were derived by applying true experimental results from nuclear physics rather than hypotheses, they are reliable and easy to understand.