Chen Jihong

Infrared Human Face Auto Locating Based on SVM and A Smart Thermal Biometrics System

The SARS epidemic resulted in the introduction of IR thermal camera for non-voluntary screening on human face for fever symptoms. However, two major problems emerged. One is the temperature measurement precision, which is not adequate enough. The other is the poor automatic ability. This paper analyses the importance and deals with the second automation problem. We discuss the inherent consistency of SVM with the pattern recognition in infrared image. A smart biometrics system that automatically detects human face in infrared video and performs temperature measurement is implemented. The potential for illumination invariant face recognition using thermal IR imagery is fully utilized. This potentiality is approved by the result of infrared human face detection experiment based on C-SVM

Design of servo system for 3-axis CNC drilling machine based on XPC target

As special equipments, the CNC drilling machines require servo systems specially designed. So there is a substantial waste of time and energy. In order to solve this problem, a design proposal for the servo system of 3-axis CNC drilling machine based on xPC Target is presented in this paper. Taking a CNC drilling machine model as the experiment platform, the block diagram of the servo system was designed using SIMULNK tools, and compiled into a real time system by VC complier, which could run on X86 computer. Rapid developing of a servo system for 3-axis CNC drilling machine is easily implemented by this proposal. The experimental results demonstrate that the feed system of the drilling machine model could carry out a quick precision positioning.

A Kind of Embedded Electric Power Steering System Based on DSP LF2407

The presented electric power steering system (EPS) based on embedded microprocessor DSP LF2407 applies to vehicle steering driving. The hardware of the system includes data acquisition module, data storage, calculating module and embedded microprocessor DSP LF2407. The data acquisition module is responsible for gathering, filtering and transformation for the torque, vehicle and motor speed signal; The data storage and the calculating module complete data memory and calculation; The output module fulfills the PWM signal transmission; DSP LF2407 controls the entire system and communication among various modules; The software of the system includes EPS controlled system software developed by the embedded microcomputer system. The system has realized the compound control joined the forward feed, enhanced the EPS control systems rapidity and the accuracy, obtained the better control effect

Field Device Communication Based on IEEE 802.15.4

IEEE 802.15.4 is a useful standard for wireless factory communication. Based on it, we give several solutions for cyclic data and non-cyclic data transfer, among which GTS (guaranteed time slot) can be assigned while a device requiring dedicated bandwidth or low-latency. But the control process for GTS is so complicated that the performance is degraded in applications. In this paper, the problems caused by GTS management in cyclic data transfer are analyzed and a GTS pre-allocation in such situation is proposed. Then we give the optimized solutions for field device communication which have better performance of simple control, lower jitter, less latencies and the minimum modification to the standard

Datacloud fusion in three-dimensional laser comparator

Abstract A three-dimensional laser comparator for dimensional inspection is introduced. With this comparator, the part’s surface is scanned by structured laser light reflected from a rotating mirror. To meet the versatile requirement for dimensional measurement of industrial parts, a stepper-motor-controlled turntable allows the entire part to be scanned. A multi-view datacloud merging technique was developed to fuse the datacloud scanned from different views providing the complete information of the part surface for dimension calculations. Since calibration of the turntable’s rotation center is the key to multi-view datacloud merging, this paper discusses several methods for calibrating it.

Research and Development of Thermal Error Compensation Embedded in CNC System

The effective compensation upon machining error, which is given rise to by machine tools thermal deformation, is an important fashion of improving machining efficiency in CNC system. The external thermal error compensation method is mostly adopted because of the closure in conventional CNC system. In order to solve embedded integral problem of real-time thermal error compensation function in CNC system, an concentrating approach is introduced by integral design. Of a concentrating manner, the thermal deformation error of X-axis screw is modeled and analyzed in THK6370 Horizontal processing centre. Not only is the inserted thermal error real-time compensation function realized in complete open CNC system, but also can the thermal error on-line real-time compensation be executed. Finally, the experiment validates the concentrating mode and the effective compensation of thermal deformation error can be implemented upon THK6370 horizontal machining centre X-axis screw.