Papers by Author: Guo Ping Li

Abstract: Bottom dead center (BDC) is an important performance index of press,but how to precisely evaluate the accuracy of BDC is a technical problem faced by the press industry. Based on fuzzy judgment method and analytic hierarchy process (AHP), this paper constructs a comprehensive evaluation index to analyze and evaluate the position of the BDC accuracy.Evaluation step is a system operated by selecting evaluation factors and building evaluation set to determine the comparison matrix, to calculate the weight of each factor, and to establish fuzzy evaluation matrix, and through comprehensive evaluation model to judge the BDC accuracy level. It shows that this evaluation method can effectively evaluate the accuracy of press.

Abstract: this paper designs a redundant second fall detection device. On the basis of the traditional mechanical press slider second fall detection device, this new type device adds an MCU detection unit independent of traditional PLC system. Using the magnetic rotary encoder to replace traditional photoelectric encoder, realize non-contact measuring angle, which can reduce the probability of component failure. Compared with the traditional second fall detection device, this kind of redundant type second fall protection device can greatly increase the safety performance of the mechanical press.

Abstract: It is very important to control mechanical press slide height precisely when it works because it will lead to loss of stamping accuracy while the slide height error appears. The paper designed a novel controlling device based on linear encoder to adjust slide height dynamically. Equipped with high-precision linear encoder on the mechanical press slide, the height of slide measured by micro-controller real-timely, the device drives the controlling motor to adjust the position of slider if slide height error occurs.

Abstract: The design of a mechanical press slide bottom dead center measurement device which is based on the macro-micro adjustment is presented. This device has macro-micro adjustment function, which is also stable and credible in installation. The functions of press slide bottom dead center repeated positioning precision automatic measuring, analysis and display are implemented by using the technologies of eddy current sensor, PCI7422 data collection card, LED display and combine with the multi-parameter assessment from the system software, etc. It is small, portable, high precision and practical.

Abstract: Orthosesare important tools to help patients in rehabilitation andas well asfor theirself-care of disables in clinics. Traditionally, orthese are made manually, which is time consuming and error prone. Digital manufacturing of orthosescan significantly improve the efficiency and reduce lead time compared to tranditionalmethods.This paper attempts to conduct a review on theorthoses manufacturing method based on digital technology including Computer Aided Design (CAD), Comupter Aided Manufacture (CAM) and Reverse Engineering (RE) by examining state-of-the-art academic and industrial reserch.In this paper, the rationale behindthe development of orthoses manufacturing methodsbased on digital technologies isaddressed firstly, followed by adescription ofthecharateristicsofideal orthoses manufacturing methods. Next, some selectedresearchesindigitalorthoses manufacturing in terms of patents and academic papers isreviewedand evaluated against criteria foridealorthese manufacture. Finally thetrend of digital manufacture of ortheseisdiscussed and summarized.

Abstract: According to the situation that conditional Braille book is difficulty in publication and its amount is small. This paper puts forward a tactile display system which can transform content of common e-book to Braille information, and the blind comprehend the text by touching the Braille formed by the tactile display device. This Braille tactile display system extracts Chinese characters by OCR technology. The text recognized is segmented into word blocks according to the rule of Braille word segmentation before transforming to double-phoneme mandarin Braille. It uses dsPIC30F2010 to receive Braille signal and then controls the piezoelectric actuator array to output corresponding displacement.

Abstract: An effective online handwritten numeral recognition system is designed based on the Matlab GUI interface. The coordinate locations of the handwritten numerals are recorded, from which the stroke direction variations and the 2-dimensional distance between the starting point and ending point of the numeral are obtained as the features, which are encoded into 42 bits binary sequence, and then input to the Hopfield neural network. The associative memory function of the Hopfield neural network can implement the learning and recognition of the handwritten numeral. Testing results show that the designed system has high recognition rate and fast recognition speed.

Abstract: Aiming to avoid the skidding of a moving electric pallet truck, a new anti-skid method was proposed in this paper, which changes the proportion of enduring pressure between the driving wheel and trundles of the electric pallet truck. And a hydraulic anti-skid system was built up according to this method. Based on the theoretical analysis of the hydraulic anti-skid system, simulations were carried out by using AMESim and Matlab/Simulink software, and the anti-skid experiments were implemented. The results of simulations and experiments all show that the designed hydraulic anti-skid system can prevent trucks from slipping and can realize accurate and real-time anti-skid control.

Abstract: According to the mathematical model of brushless DC motor (BLDCM), control equations of BLDCM speed control system and simulation model were established for steering control device in electric pallet truck based on transfer function in Matlab/Simulink. The fuzzy adaptive PID control method was introduced to speed control system, and it can realize PID parameter’s online adjustment. Simulation result shows that the designed speed controller based on fuzzy adaptive PID has better dynamic and static performance than the controller based on traditional PID, and the control accuracy is also greatly improved.

Abstract: A temperature monitoring system for mechanical press’s bearing is presented. As multipoints of the cranks need to be monitored, the system is based on RS485 BUS, which is a distributed, real-time and reliable temperature monitoring net. It consists of the temperature monitoring sub module and the master module. The sub module gets temperature data via thermocouple and MAX6675. The master module controls the whole system with an ARM IC. The system can judge whether the temperature of bearing has exceed the limited value or the temperature is rising too fast, and send alarm signal to stop the press in those cases. Configuring this temperature monitoring system to the large or medium scale mechanical press can avoid the accident like bearing-burnt effectively.