Papers by Keyword: Center of Gravity

Abstract: This research proposes a novel method of recording the features of mine mills digitally by 3D laser scanner and its application. This method enables to obtain their shape features in short time independent of the expert's drawing skill. It also enables to evaluate the shape feature values, such as the position of the center of gravity, based on the obtained 3D digital data. In addition it may be possible to get a clue to clarify the process of varying the shape of mine mills. The mine mills described in this paper are remains discovered in the mountains of Yu-no-oku gold mine locating in Minami Kuma County in Yamanashi prefecture, Japan.

Abstract: The bus is a vehicle for transport the passenger to the destination safely. The bus manufacturing is produced directly from the company and the bus has been modifying from the bus garage. The Bus modify into popular use in the domestic because it is cheaper. The modified bus is also a safety issue because these vehicles to the tilted test 30 degrees most of the test is not passed. The center of gravity is influenced to the stability of the bus. Which the Company or modify bus garage can not know the position of the center of gravity in advance. When the bus is used to build a center of gravity located in improper placement. Hence, the test does not pass 30 degrees tilt.Which required costs to adjustment and test again. This paper was intended to study the variables that affect the center of gravity of the bus include engine placement, adjustment pressure into air suspension before build bus body, bending chassis, characterized by mounting to the chassis frame. Studies using instruments find the center of gravity of the bus used computer simulation center of gravity nearby real bus. The variable adjustment in order to design a bus with the appropriate center of gravity. Research has found that different variables adjustment engine placement characterized by mounting to the chassis frame have an affect to bending chassis relate to the center of gravity change, Therefore, the variables to be optimized, it is possible to design a bus safety.

Abstract: The farmers growing Para rubber in Chiang Rai, northern Thailand, have faced many problems derived from depreciation from middle-men and there are insufficient places offering a reasonable price to them. The purposes are (1) to study a location for a rubber purchasing center in Chiang Rai, (2) to analyze profitability from an investment in the rubber purchasing center, and (3) to study the externality of the projects impact on the environment. This study is based on 10-year secondary data (2003-2013) derived from the Office of the Rubber Replanting Aid Fund. The result of the study found that the rubber purchasing center should be located in Tung Kor Sub-District, Chiang Rung District, Chiang Rai Province. A financial analysis illustrates that Net Present Value of the project is equal to positive 34.72 that means net profit is more than net cost or it is appropriate to invest in the project. Interest Rate of Return is equal to 26% which is higher that discount rate, therefore, this project is an interesting investment. Payback period is equal to 4.24 meaning this project will meet a breakeven point within 4 years 2 months and 27 days. Also, break-even point in quantity is equal to 1.12 which means this project needs sale volume of 1.12 million units to meet the breakeven point. The environmental impacts shows both positive and negative externality that more concern has put on water, air, and noise pollution derived from a production process of the project.

Abstract: This paper focuses on making some review and observation on the performance of equipment named Mass Properties Measurement System (MPMS) which capable to calculate the center of gravity (CG), moment of inertia (MOI) and Product of Inertia (POI) of a satellite. Before approving to receive such a huge machine/equipment consist of mechanical and electronic structure, National Space Agency (ANGKASA) which acts as a Malaysian Government Agency has to go through an Acceptance Test Procedure (ATP) to compare with the factory acceptance result on its performance review. The Factory Acceptance Test (FAT) for this machine has been done earlier in United States (USA) as the equipment is manufactured in Connecticut, USA. This ATP is responsible on determining the requirements of a specification or contract are met or not by conducting test which is commonly applied for engineering and its various subdisciplines and the test have been witnessed by a Malaysian Research Institute; SIRIM Berhad, local and international contractors as well as the principal or manufacturer of the equipment itself and took place in ANGKASA, Banting, Selangor. It may involve chemical tests, physical tests, or performance tests by comparing the results with FAT [1].POI-1000M Rotary table, a rotor, deadweights, a compressor and a beam are the main components to be used for the acceptance performance test assisted by a control system for operators to calculate the desired measurements. Results confirmed that the ATP and FAT results are finally been compared and the equipment is successfully approved.

Abstract: The purpose of this paper is not to elaborate the bionic pattern of walking robot, but to elaborate our own simple idea of a 4 degree of freedom (DOF) walking robot with the ability to walk on flat surfaces, rotate and climbing upstairs, which is composed of vertical moved legs with a rotary foot and a controlled mass for stabilizing. In this paper, based on the former idea, a prototype model of a 3-DOF walking robot is presented for walking only on flat surfaces. This walking robot is actuated by servo motors. The paper covers the kinematics, centre of gravity analysis, description of the robot and its control system made using Pololu controller. Experiments confirmed the feasibility of the proposed design.

Abstract: This paper focuses on the capabilities of equipment known as Mass Properties Measurement (MPM) to calculate the center of gravity (CG) of a jig or an adaptor, which is used for mounting a structural model of Malaysian satellite, RazakSAT on POI-1000M Spin Balance Machine. The adaptor needs to be designed accurately to precisely accommodate the bolt sizes in both sides of the Device Under Test (DUT) side and the rotary plate side. In other words, the adaptor must be able to act as a good interface plate. A Malaysian research institute, SIRIM Berhad was chosen to undertake the design and manufacturing of the adaptor according to the specifications made by ANGKASA. The list of requirements of MPM should be considered during measurement to have optimum results, so that the satellite fixture onto the rotary table can be preceded for further calculations. Space Electronics (SE), the manufacturer for this MPM machine, has provided the control system for operators to calculate the required measurement such as CG, moment of inertia (MOI) and Product of Inertia (POI). Results confirmed that the simulation and experimental values are successfully obtained.

Abstract: The purpose of this paper is to elaborate not on the bionic pattern of walking robot. Our own simple idea of 4 degree of freedom (DOF) walking robot with the ability to walk on flat surfaces, rotate and climbing upstairs was made using vertical moved legs with rotary foot and additional controlled mass. In this paper, based on former idea, prototype model for only flat surface walking task 3 DOF were presented. Parts of the robot are moving thanks to servo motors. The paper contains kinematics and centre of gravity analysis, presentation of robot and its control system made using Pololu controller. Conducted experiments confirmed presented idea.

Abstract: This paper presents the experimental determination of the moment of inertia of USM e-UAV by using pendulum method. Compound pendulum experiment is used to determine the moment of inertia about x and y axes while the moment of inertia about z-axis is determined using bifilar torsion pendulum method. An experimental setup is developed with appropriate dimension to accommodate USM e-UAV. Experimental data are presented and discussed.

Abstract: Legged living creatures can move on any kinds of terrain with good adaptability. They read the terrain conditions and repeat inherent or acquired obstacle crossing sequences, which can be imitated mechanically for the design of a Quadruped. For the prototype model and the step, four corner distances are determined according to the desired body angle and the continuous locomotion sequences are determined. Also, the requirements to satisfy three conditions for step-down are introduced, which makes it possible to determine the exact number of steps in the second phase of step-down. Since step-up is the reverse of step-down, all the governing parameters are the same and the locomotion sequences of step-down are also the reverse of step-up, except for the case of walking-down by gravity. The dimensions of a suggested quadruped are used to calculate the crossing performance for the purpose of comparison.

Abstract: This paper describes a method for generating a center of gravity trajectory of a biped humanoid robot under variable reference ZMP trajectory. A simple inverted pendulum model (SIPM) is used to calculate a center of gravity (CoG) trajectory from a reference zero moment point (ZMP) trajectory with an analytic form, which is based on the Fourier series. Fundamentally, we used a time segmentation based approach. For each segment, we defined its duration and boundary conditions, which are the key parameters of ZMP trajectory design. After designing the ZMP trajectory in each segment, we can automatically calculate the CoG trajectory by matching the boundary conditions and by calculating the coefficients between the time segments. The reference ZMP trajectory can be changed by updating the boundary conditions during walking. We successfully verified the proposed method through full-body dynamic simulations with variable step length.