Applied Mechanics and Materials Vols. 300-301

Abstract: Today, when the robot technology is booming, various sensors and intelligent functions that applied in robots can be transferred and applied to the unmanned aerial robot. It will make the unmanned aerial robot not an ordinary UAV any longer, but an intelligent robot that can fly. Conventional UAVs are not well suited for use in confined spaces, such as small passageways or indoor halls, e.t.c. The multi-rotor copters have the vertical take-off and landing (VTOL) ability for indoor flight. The most popular research topics for multi-rotor copters are Quad- copter and Hexa-copter. The objective of this research is to design and build a hexa-rotor aerial robot. We used AVR microcontroller as the flight control system, and use three-axis gyroscope and three-axis accelerometer for attitude sensing of the aerial robot; the flight altitude is estimated with barometric altimeter; the closed loop control of the aerial robot is carried out with PID control to meet the requirements, such as self-balancing, hovering and etc. Multi-sensors had been applied to the hexa-rotor aerial robot, and verified the feasibility with experiments. A universal test platform was designed to test the stability and balance of the Hexa-rotor aerial robot. An external force was applied on the aerial robot from pitch, roll and yaw direction, the aerial robot can return to self-balancing flight quickly. Finally, the hexa-rotor aerial robot can make a stable hovering during the outdoor test fly.

Abstract: Most hexapods that are currently available on the market are expensive and have extremely high positional and orientation accuracies. Although the positional accuracy is high the viewing angle is limited to 60°. These hexapods are designed with a small viewing angle, as they are not optimised for radio telescopes. The aim of this work is to highlight the various factors that should be considered during the design of a 6-3 Stewart platform for pointing applications. These factors are illustrated by presenting the case study of a small custom hexapod that is designed, built and tested. Modelling of the Platform is performed through the implementation of existing kinematic and dynamic models that could be verified through comparison to simulation results in literature. Components designed for the hexapod include the linear drives, base joints, platform joints, electronic controller and graphical user interface. The design process is documented and design decisions clearly motivated. Performance of the Stewart platform is measured with an inclinometer and the ability of the platform to track a sun simulation path is presented. Specifications which the hexapod is able to achieve include a viewing angle of 120˚±0.3˚ and the ability to carry a payload of 1kg.

Abstract: This paper is concerned with optimisation of the power produced by a photovoltaic (PV) panel through designing, building and implementing maximum power point tracking (MPPT). In the literature, the MPPT has been normally approached either electronically (using a DC-to-DC converter) or mechanically (controlling the orientation of a PV panel). In this paper, these two approaches are combined to yield more power. To this end, for a given PV panel (available at the first author’s institution) which is already equipped with a mechanical tracking device, a Buck (DC-to-DC) converter is designed to improve the power saving which could be achieved by the mechanical tracking alone. Also, new electronic and mechanical MPPT methods are developed, and their combination, so-called electro-mechanical MPPT, is tested in a real environment to verify its usefulness.

Abstract: Selecting a suitable locomotion way for a mobile robot is critical for succeeding its mission. This paper introduces a cylinder-like robot that can locomote by means of either rolling or jumping on the ground. First, design of the robot is described to explain the mechanism for enabling rolling and jumping by using only one DC motor. Second, the design is analyzed in terms of energy efficiency and compared to a couple of hybrid mobile robots.

Abstract: A novel rain gauge based on acoustic self-calibration principle is proposed in the paper. Acoustic self-calibration principle can eliminate the uncertainty of the velocity of ultrasound and achieve accurate measurement of rainfall. The rain gauge not only overcomes the influence on the rainfall measurement under intensive rainfall conditions, but also improves the precision of rain gauge. Plenty of experiments have been done to validate the design. Both theoretical analysis and experimental results show the effectiveness of the rain gauge. A full description of the rain gauge and implementation are presented.

Abstract: We present the path planning techniques of the fire escaping system using multiple mobile robots for intelligent building. The controller of the mobile robot is MCS-51 microchip, and acquires the detection signal from flame sensor through I/O pins, and receives the command from the supervised compute via wireless RF interface. The mobile robot transmits ID code, detection signal, location and orientation of the mobile robots to the supervised computer via wireless RF interface. We proposed A* searching algorithm to program escaping motion paths to guard peoples moving to the safety area using mobile robots, and develop user interface on the supervised computer for the fire escaping system. In the experimental results, the supervised computer locates the positions of fire sources by mobile robots, and programs the escaping paths on the user interface, and transmits the motion command to the mobile robots. The mobile robot guards peoples leaving the fire sources.

Abstract: Returned laser detection is bottleneck in remote active laser detection. A practical small laser tracking system with simple structure based on four-quadrant detector (QD) is presented in this paper. For the volume restriction in weapon systems, design a small laser receiving optical system. An orientation calculation circuit based on the Sum and Difference circuit with Divisional normalization algorithm is designed to decrease the burden on processor. A simple MCU circuit based on high-speed chip C8051F020 is generated, accomplishing AD-conversion and further calculation. Through programming of the electric signals from the orientation calculation circuit with C8051F020, a control signal used by the missile guidance is formed. Laser signal receiving experiment is conducted by the circuit board as presented in this paper. It is possible to achieve the ideal requirements, and provide a good foundation for collaborative processing of other sensor signals to jointly get guided control commands.

Abstract: This paper used the ADXL213 dual-axis tilt sensor produced by Analog Device and NXP company's LPC1114/301 series microcontroller to make a digital inclinometer. The inclinometer has the advantages of reliable work and high measurement precision as well as the advantage of low cost. The paper mainly discussed the system hardware circuit design, software flow and the factors affecting the accuracy of the analysis, also proposed and implemented feasible compensation approaches, designed and manufactured a digital inclinometer in kind.

Abstract: Abstract. In order to improve the tracking accuracy of 3D dynamic acoustic array to 2D maneuvering target in colored noise environment, the adaptive interacting multiple model unscented particle filter algorithm based on measured residual is proposed. The 3D motion acoustic array tracking system dynamic model is established, and initialized probability density function also is defined based on unscented transformation, after that, the measured covariance and state covariance are online adjusted by measured residual and adaptive factor, then the self-adapting capability of filter gain and the real-time capability of posterior probability density function are improved. Finally, the simulation results between different algorithms show the validity and superiority of the presented algorithm in tracking accuracy, stability and real-time capability.

Abstract: One of the key technologies for high-resolution camera is the analog front end (AFE) design, which is between the lens and image system process (ISP). The 2 major evaluations of AFE are to evaluate the noise and the ratio between the RGB pixels. Hence, based on the charge coupled device (CCD) image sensor, we present our proposed AFE design to evaluate the CCD noise of the output image with a lower dark current. Our proposed AFE board design is to employee the 1080p (1920×1080) CCD image sensor and its corresponding timing controller with the digital-analog converter (ADC). Our results indicate that our design has the high performance among 6 different digital brands in the low noise applications. Moreover, the CCD sensors with the different resolutions can be installed within the same socket of our AFE board, which can also simultaneously support 3 types, Bayer, Truesense, and Black/White, color filter array.