Li Ming Wu

Research of FWP Process Deformation Compensation Forecasting on the Basis of TS-FNN

After analyzing the influencing factors of flexible workpiece path(FWP) process deformation, this article proposes the basic conception of process deformation intelligent forecasting and compensation, start from the process modeling method of Takagi-Sugeno fuzzy neural network, to modify the classic FNN model and construct the multiple input/output TS-FNN model for FWP process control; with LMS law and steepest descent method, antecedent network membership function parameter adjustment and descent network parameter study method of TS-FNN model is deduced; finally to carry on comprehensive simulation on TS-FNN model, the result shows the constructed model is better than BP neural network and RBF neural network for an order of magnitude on predication accuracy; in the quilting process of flexible objects, compensated by TS-FNN, the path processing obtains good approaching effect, testing result indicates that the position error scope of quilting is from 0.078 to 0.162(mm), the accuracy is higher than excellence grade of quilting which refers to national standard FZ/T81005-2006.

Measurement and Simulation of Automotive Eddy Current Retarder Based on Virtual Reality

Structure and working principles of eddy current retarder (ECR) are discussed, as well as performance requirements of real-time virtual testing and simulation. On the basis of hardware testing platform, virtual models of vehicle and retarder are embedded into application program. In the testing system, Vega API function library is used for second development to control the 3D models, and Visual C++ is used for mathematical models call from MATLAB to simulate the working condition. Integrated with virtual instrument and virtual environment, the limitation of former simulation is broken through. Monitoring and testing on eddy current retarder are achieved efficiently and visually. Besides, the virtual test data is not only compared with the practical vehicle test data to correct the technical parameter of eddy current retarder, but also compared with the simulation of mathematical models for further study. The testing system gives evaluation on the performance of the retarder in different vehicles, so it expands application range and heightens testing efficiency.

Researching a Online Method of Measuring Three-Dimensional Deformation for Large Overhead Crossbeam

Aiming at the difficulty of online measurement for three-dimensional deformation of large overhead crossbeam in gantry CNC machining centre, this paper proposes a measuring method based on multi-points attitude of crossbeam-body. Real-time measuring the attitudes of some equidistant points on crossbeam-body, dealing with the measurement information by adopt shockproof filtering, wavelet denoising and smoothing. Then infer the formulas to calculate deformation of each point along different directions of x-axis, y-axis, z-axis. The experiment uses triaxial acceleration sensor modules to measure crossbeam attitude. Experimental results show that the minimum deformational angle can be measured low to 0.06°. And if the spacing between sensor modules has mm level accuracy, the precision of calculation about deformation can reach up to 10-3mm level. In addition, this method is strongly suitable for on-site environment, and it can lay a foundation for further researching about prediction and compensation in the CNC processing.

Research of Hand Gesture Recognition in Multi-Touch Projector-Camera System

This paper studys the feasibility of the shadow of interactive gestures on the projection screen as the control instructions in a projection interactive system. With regard to complex background of the projection screen, we put forward to detect mobile gestures and the shadows of gestures by using the way of the Gaussian mixture model. Relative to the non-rigid body interaction gestures, The shadow of gestures has a simpler two-dimensional characteristics and greater differences from the other regions of the projection screen. Based on this characteristics, we adopt Ostu threshold segmentation algorithm to remove the interference of the gestures. Then we use the mixed way of the radial symmetry transform and curvature threshold to position the interactive fingertips as interactive instruction of the projector-camera system. Conctroling the screen in a wide range without carrying any equipment is completed. The experimental results show that this method is easy to operate and has a high accuracy rate.

A New Method Applied to the Multi-Parametric Nonlinear Compensations of Computer Numeric Control Bender

Complex Moving Least Squares and its key attributes as basis functions and support region radius were discussed and studied in this paper. Owing to the weak performance of traditional Moving Least Squares when applied to asymmetrical sampling points set, an improved Moving Least Squares named dynamic radius Moving Least Squares was designed, whose support regions radius at fitting point dynamically adjust as the density of local point subset. At last, it is applied to multi-parametric nonlinear compensation of computer numeric control bender through comparative fitting experiments and simulations on couples of data compared to traditional Moving Least Squares. The results of experiments and simulations indicate that the new algorithm makes a great progress on computational complexity, fitting smoothness and fitting accuracy, especially the accuracy in dense points region compared to traditional Moving Least Squares.

Research on Multi-Core Collaborative Computing for FWP Image Processing Algorithm by FPGA

On the basis of analysis of research on embedded soft hardware collaborative design method, image processing SOPC collaborative design principle is elaborated, relation between complicated algorithm time and soft hardware implementation and the implementation method to accelerate algorithm by multi-processor and multi-core is studied, thus the logical relationship between equipment IP core on the chip with Fast Simplex Link(FSL) bus and bus bridge, connecting conditions and application flow is organized. Finally, design SOPC, for which, multi-core and multi-processor collaborative work with the core of PowerPC 405 processor by taking flexible workpiece path (FWP) image as an example. The test manifests that the computation speed of SOPC designed in this passage is higher 10 times than that of common single-core SOPC in terms of image processing computing, effectively solving the problem of slow speed for computing image preprocessing by software in the embedded system.

A Strapdown Measurement of Vehicle Posture

Vehicle bodywork posture measurement has been a gordian technique in automotive．This paper presented a non-gyro bodywork posture measurement program．Using only one triaxial acceleration transducer with wheel speed encoders it provided a solution of calculating real-time bodywork posture．A lot of streamlining had been made within this program in order to assurance system for real-time performance．Concretely it gave an example of hardware implementation circuit through using LPC1758 as MCU and MMA7260 as triaxial accelerometer, as well as the noise filtering solusion for the circuit．This strapdown measurement has the advantages of high reliability，adaptability and good real-time performance，its precision meets the necessary accuracy requirement of normal application.

The Reconfigurable Embedded NC System Based on FPGA

The hardware and software design method of reconfigurable embedded NC system which makes use of FPGA’s abundant logic resources and programmable characteristics is presented. It introduces the scheme of a embedded NC system which has regarded FPGA as the control center. It mainly represents the thought of reconfigurable design, the speed control of stepping motor, and the communication of FPGA and PC. As a result, this system has fast response and strong reconfiguration ability. It can reduce the number of peripheral interface devices and result in costreduction.

Adaptive Ant Colony Algorithm Used in WSNs Routing for Information Acquisition of Manufacturing Process

Ant colony algorithm (ACA) is employed and improved in routing protocol of information acquisition of manufacturing process based on wireless networks. Weighting factor for paths selection is defined as an exponential variable in adaptive ACA. In this way, it prevents the weighting factor from excess increasing or rapid reducing to 0 which results in local optimum. This approach can dynamically adjust paths selection and improve global search ability by optimizing global policy. Adaptive ACA consumes the least time in the process of searching the most optimized paths and searches the shortest paths under the same of iterative loops. Under the same condition of the information heuristic factor and the expected heuristic factor, the algorithm shows good adaptation, realizes the load balancing between paths and resolves the dynamic adjustment problem.