Long-Jyi Yeh

The optimal control of material removal rate with fixed tool life and speed limitation

Abstract A material removal control (MRC), model to achieve the optimal cutting rate control of a cutting tool during machining is established in this study, which can direct a project towards reaching maximal profit. This paper not only applies the material removal rate (MRR) into the objective function mathematically, but also implements the calculus of variations to resolve the cutting rate control problem comprehensively. In addition, a dynamic solution for the control of the MRR is proposed and the decision criteria for selecting the optimal solution are recommended. Moreover, the sensitivity analyses for decision variables of the optimal solution are discussed. This study provides an efficient tool for controlling the machining rate for production engineers in present-day manufacturing.

The design and application of a robotic vacuum cleaner

Robots are widely used in modern industrial manufacturing, in households, in entertainment, and in the security sector. To facilitate targeted functions, interactivity in conjunction with high quality sensors play essential roles. In this paper, an intelligent and interactive robotic vacuum cleaner is developed. By using awireless transport protocol (802.11b), the user can monitor the robots path and remotely manipulate its movements with a pc interface. Research has developed two kinds of functions — an auto-vacuum-cleaning mode and a remote-manipulating mode. For the auto-vacuum-cleaning mode, two pathsearching algorithms are developed — one is the right-side edge-searching and obstacle2 avoiding algorithm, the other is the S-type sweeping and obstacle-avoiding algorithm. Additionally, a system program for plotting the robots path is developed. By calculating data submitted from a micro controller and an error compensator, the immediate path of a robot is shown on apc monitor. Therefore, further path correction commands can be sent to the robot by the remote-manipulating mode in the main server pc. Consequently, a prototype robot has been manufactured and tested in the laboratory

Optimization of Allocation and Noise Reduction on Multi-Noises System by Using Genetic Algorithm

An optimization of a layout plan and noise reduction on multi-noises system is considered. In this paper, a novel approach, a genetic algorithm (GA) based on the principles of natural biological evolution, is used as an optimizer. [1] By GA optimization in adjusting the locations and the required noise reduction for each piece of noisy equipment, the deviation with respect to the targeted noise value along the systems boundary line specified by EPA (Environment Protection Authority) can thus be minimized. In addition, the techniques of binary genetic algorithms (BGA), reproduction, crossover mutation and elitism are applied in GA searching. The numerical cases of multi-noise systems are exemplified. Results show that the correctness of the GA method is acceptable. The optimal design of noise control by adjusting the location and choosing the proper noise reduction measures on equipment proposed in this study offers a quick and economic approach.

Numerical Assessment of Optimal One-Chamber Perforated Mufflers by Using GA Method

Research on new techniques of perforated silencers has been addressed; however, the research work in shape optimization for a volume-constrained silencer requested upon the demands of operation and maintenance inside a constrained machine room is rare. Therefore, the main purpose of this paper is not only to analyze the sound transmission loss of a one-chamber perforated muffler but also to optimize the best design shape under space-constrained conditions. In this paper, both the generalized decoupling technique and plane wave theory are used. The four-pole system matrix used to evaluate acoustic performance is also deduced in conjunction with a genetic algorithm (GA); moreover, numerical cases of sound elimination with respect to pure tones (150, 550, 950 Hz) are fully discussed. Before GA operation can be carried out, the accuracy of the mathematical model has to be checked using Crocker’s experimental data. The results reveal that the maximum value of sound transmission loss (STL) can be optimally and precisely achieved at the desired frequencies. Consequently, the approach used for the optimal design of the one-chamber perforated mufflers is indeed easy and quite effective.

The development of an automatic frequency response measuring and classification system for earphones

Abstract This study introduces an automatic classification system that uses an electroacoustic analyzer to measure the frequency response of earphones. This system was designed using the Pro/E package and improved via testing. The system controller used in the study is the Microchip PIC18F4520 microcontroller. The controller is connected to an electroacoustic analyzer and various motor drives to control the process. The classification system is divided into two parts. The first part is the placement of the earpiece into a matrix tray. Two electric tables and a linear rail are adopted to build a two-axis X-Y table. Then, a device is introduced onto the X-Y table that moves the earpiece to the correct point and drops it into a10×10 matrix tray. The second part is the classification mechanism. According to the results of the frequency response, the earpieces can be organized into eight classes. When receiving the classification results from the frequency response measuring device, the controller will plot the shortest path for moving an earpiece. Thereafter, the specified class number will be recovered and the coordinates of the X-Y table reset. This study proposes to establish an automatic classification system for earphones. Each earpiece will be appropriately dropped into the correct position within the classified matrix tray when the frequency response’s classification is complete and the message forwarded to the controller.

The development of an acoustic earpiece, an auto-inspection, and a coil contact point recognition system

Abstract The purpose of this paper is to develop an automated acoustic inspection platform for an earpiece manufacturing. An 8-pin detector has been designed to automatically locate a coil which is inside an earpiece drive. This 8-pin detector is composed of eight probes. Voltage data will be obtained by a A/D converter via scanning and reading the earpiece when the detector contacts the earpiece’s drive. The location of the coil can be ascertained from the voltage data. The automated acoustic inspection platform uses a microcontroller (PIC18F4520) to control the integrated system sequence and the actuators, including the pneumatic cylinder solenoid and the step motor drive. Developed, here, is an automated machine which moves earpieces from the plate of the earpiece to a claw. The claw, then, moves the earpiece into position to detect the coil’s location. After locating the coil using an 8-pin detector, an acoustic inspection process will be executed automatically. The time of the inspection process is about 5 seconds.

An Experimental Study of Low-Frequency Vibration-Based Electromagnetic Energy Harvesters Used while Walking

The goal of this paper is to develop and experimentally test portable vibration-based electromagnetic energy harvesters which are fit for extracting low frequency kinetic energy. Based on a previous study on fixed vibration-based electromagnetic energy harvesters, three kinds of portable energy harvesters (prototype I, prototype II, and prototype III) are developed and tested. To obtain the related parameters of the energy harvesters, an experimental platform used to measure the vibrational systems electrical power at the resonant frequency and other fixed frequencies is also established. Based on the research work of vibration theory, a low frequency vibration-arm mechanism (prototype III) which is easily in resonance with a walking tempo is developed. Here, a strong magnet fixed to one side of the vibration-arm along with a set of wires placed along the vibrating path will generate electricity. The circular device has a radius of 180 mm, a width of 50 mm, and weighs 200 grams. Because of its light mass, it is easy to carry and put into a backpack. Experimental results reveal that the energy harvester (prototype III) can easily transform kinetic energy into electrical power via the vibration-based electromagnetic system when walking at a normal speed. Consequently, electrical energy reaching 0.25 W is generated from the energy harvester (prototype III) by extracting kinetic energy produced by walking.

The Development of Wrist Rehabilitation Assistive Devices Using a Shape Memory Alloy

For the purpose of wrist rehabilitation, a new type of SMA (Shape memory alloy) wrist rehabilitation device is developed. The palm will be actuated/lifted by the SMA’s driving force when the shape memory alloy is heated up. Four wires of the shape memory alloy (SMA-Ti50Ni45Cu5 with 1.0mm in ψ) are bundled and passed through a fixed plastic block. The whole set of the SMA wrist rehabilitation devices can give support to the palm’s bending mechanism. A 500(g) adult palm is presented in the experimental work. In order to actuate/lift the palm at a sufficient rehabilitation angle, an electrical circuit of 10(A) is adopted. Consequently, the issue, here, is to present a new type of SMA wrist splint that is used to provide a specified rehabilitation angle for the wrist.

Automatic cable spooling for a robotic vacuum cleaner

The main purpose of this paper is to create a mechanism that can automatically gather and loosen the power line on the mobile cleaning robot. A single-chip Microcontroller PIC18F452 is used as a control core in the robot. The robot driven by two stepping motors is equipped with six infrared-ray-distance detectors to detect obstacles and calculate the real distance between the sensor and obstacles. Moreover, a cable rewinding/loosening controller with a three-directional tension detecting switch is used to detect the appropriate rewinding/loosening. A cable-tray used to gather the cable is driven by a DC motor. The electric power of the robot is supplied by four sets of 12 v Pb-made batteries. The vacuum cleaning robots plug-in action will be performed after the edge-searching is completed. The sweeping mode is started up and a s-type sweeping path is executed. The cable will be adjusted by using the cable rewinding/loosening controller during the vacuumcleaning process. The robot will rewind the cable while moving back to the wall socket if the ground-cleaning is completed. Experimental results reveal that the robot can rewind and loosen the cable effectively during the vacuum-cleaning process.

The visual tracking system using a stereo vision robot

Purpose – The purpose of this paper is to use vision stereo to simultaneously acquire image pairs under a normal environment. Then the methods of moving edges detection and moving target shifting are applied to reduce noise error in order to position a target efficiently. The target is then double confirmed via image merge and alignment. After positioning, the visual difference between the target and the image created by the stereo vision system is measured for alignment. Finally, the image depth of the target is calculated followed by real-time target tracking. Design/methodology/approach – This study mainly applies Sobel image principle. In addition, moving edges detection and moving target shifting are also used to work with system multi-threading for improving image identification efficiency. Findings – The results of the experiment suggest that real-time image tracking and positioning under a pre-set environment can be effectively improved. On the other hand, tracking and positioning are slightly aff...