H. J. Huang

Design of LED fish lighting attractors using horizontal/vertical LIDC mapping method

This study employs a sub-module concept to develop high-brightness light-emitting diode (HB-LED) fishing light arrays to replace traditional fishing light attractors. The horizontal/vertical (H/V) plane light intensity distribution curve (LIDC) of a LED light source are mapped to assist in the design of a non-axisymmetric lens with a fish-attracting light pattern that illuminates sufficiently large areas and alternates between bright and dark. These LED fishing light attractors are capable of attracting schools of fish toward the perimeter of the luminous zone surrounding fishing boats. Three CT2 boats (10 to 20 ton capacity) were recruited to conduct a field test for 1 y on the sea off the southwestern coast of Taiwan. Field tests show that HB-LED fishing light array installed 5 m above the boat deck illuminated a sea surface of 5 × 12 m and achieved an illuminance of 2000 lx. The test results show that the HB-LED fishing light arrays increased the mean catch of the three boats by 5% to 27%. In addition, the experimental boats consumed 15% to 17% less fuel than their counterparts.

A new calibration method for MEMS inertial sensor module

This paper presents a new calibration method to overcome the challenges of MEMS inertial sensors for underwater navigation. The MEMS inertial sensor module is composed of an accelerometer, gyroscope and circuit of signal process. For navigation estimation, it is easy to be influenced by errors which come from MEMS inertial sensors. In general, the sources of error can be categorized into two groups, deterministic and stochastic. The former are mainly including bias error, misalignment and nonlinearity; the latter contain temperature effect and signal drifting. Subsequently, the linearity calibration is used to modify the deterministic error and the wavelet analysis can suppress the stochastic noise. Therefore, the new calibration method integrated of linearity calibration and wavelet signal processing is utilized to enhance the accuracy and performance of MEMS inertial sensor module. The experimental results demonstrate that the output signal can be corrected suitability by means of proposed method.

Evaluation of MEMS inertial sensor module for underwater vehicle navigation application

This paper presents a new calibration method to overcome the challenges of MEMS inertial sensors for underwater navigation. The MEMS inertial sensor module is composed of an accelerometer, gyroscope and circuit of signal process. For navigation estimation, it is easy to be influenced by errors which come from MEMS inertial sensors. In general, the sources of error can be categorized into two groups, deterministic and stochastic. The former are mainly including bias error, misalignment and nonlinearity; the latter contain temperature effect and signal drifting. Subsequently, the linearity calibration is used to modify the deterministic error and the wavelet analysis can suppress the stochastic noise. Therefore, the new calibration method integrated of linearity calibration and wavelet signal processing is utilized to enhance the accuracy and performance of MEMS inertial sensor module. The experimental results demonstrate that the output signal can be corrected suitability by means of proposed method. (Abstract)

Design and estimation of a MCPCB-flat plate heat pipe for LED array module

Recently, high power LED is more and more important due to requirement of illumination. To achieve the greater performance of electric path and heat dissipation ability, the metal core PCB (MCPCB) is used to replace the common FR4 PCB. The MCPCB is composed of copper film, dielectric and metal base. Metal base is made of copper or aluminum and has high thermal conductivity to conduct heat from LED to heat sink. However, the low thermal conductivity of dielectric layer in the middle of MCPCB will cause the temperature raise. In this study, we use 30% diamond powder as the filler of dielectric layer and combined the PCB and flat plate heat pipe (PCB-FPHP) without metal base to enhance the effective thermal conductivity. In order to verify the performance of diamond powder PCB-FPHP, we experimental measured the PCB-FPHP and common MCPCB conducted with 3 different materials include Cu, Al and FPHP by IR camera. The experimental results shows that the thermal resistance of PCB-FPHP is 36%, 78% and 86% lower than MCPCB-FPHP, MCPCB-Cu, and MCPCB-Al respectively. It is obviously that the thermal resistance of metal base and the thermal grease cannot be neglected especially in high power application. The structure of PCB-substrate we propose in this paper can reduce the junction temperature about 0.36°C/W compare with MCPCB-substrate. It is a meaningful number for high power LED application.

A novel dual screen projection system using balance-type micromirror with piezoelectric actuator

This paper presents an innovative dual screen projection system (DSPS) to solve the problem of existing micro-projectors only being able to project a single small picture. Therefore, this study designed a balanced double micro-mirror synchronous scanning mechanism using LIGA-like technology for dual screen projection. The DSPS was composed of balance-type dual micro-mirrors as fast axis, an eccentric slow axis mechanism, and slender piezoelectric actuators. For the balance-type dual projection structure, two micro-mirrors are connected using a ¥-shape beam, so that both micro-mirrors can synchronous scanning form motion behaviors approximate to a balance. The experiments demonstrated when a voltage of 10V pp was applied, the scanning angle of the slow axis and the fast axis were respectively 5.6° and 6.8°, and their driving frequencies were respectively 7.168kHz and 9.126kHz. The DSPS were applied a voltage of 10V ac matched with a DC voltage of 1V and integrated the fast axis mold and slow axis mold, so as to simultaneously project dual rectangular and dual round pictures. The study achieves the function of a synchronous display of two images. Therefore, this DSPS is well suited for application to portable projection equipment in the future.

A novel miniaturization actuator using a symmetric piezoelectric pusher element for pocket sun-tracking system

A novel pocket sun-tracking system was developed using a symmetric piezoelectric plate and a Ni-Co alloy micro-pusher element. A LIGA-like technique was employed to manufacture a Ni-Co alloy micro-pusher with a Vickers hardness value (HV) of 550, which was then attached at the midpoint of the long side of a piezoelectric plate with dual electrodes to construct a symmetric piezoelectric pusher element (SPPE). The research integrated the concept of LEGO® bricks, and three different vibration modes of the SPPE were designed to develop a miniaturization SPPE actuator, which was able to rotate a hemisphere concentrator lens along three perpendicular axes. The experiment demonstrated the pocket sun-tracking system moving precision to reach 1° and the rotation speeds to reach 50 rpm at a driving voltage of 30Vpp. In the future, this miniaturization SPPE actuator may be used for a number of applications, such as sun-tracking systems for green energy harvesters and bio-devices for use in the biomedical field.