Applied Mechanics and Materials Vols. 110-116

Abstract: Building a research framework for a Parallel Hydraulic Hybrid (PHH) Prototype with Hydraulic Regenerative Braking and Launch Assist (HRB/HLA) System for small and medium sized vehicles has been attempted. The objective of this work is to capture lost Kinetic Energy during braking and store that captured energy in a pressurized accumulator to be used again to assist accleration. The experimental implementation and validation of the Regenerative Braking System concept for light vehicles has been done using a go-kart powered by a single cylinder Honda engine to demonstrate energy savings in a real life braking scenario. A light weight test system accommodating all the Hydraulic Breaking System components mounted at the rear of the go-kart has been successfully built and tested.

Abstract: The primary objective of this work is to optimize the lift-to-drag ratio of a waverider-based configuration by a new global optimization method — the adaptive surrogate model (ASM), which is based on latin hypercube computer experiment and kriging surrogate model. Additional design points will be added in experiment set of points during iterative process. Design spaces of each variable are reduced by an adaptive reduction radius, which is improved gradually by the adaptive inconsistency of optimum solutions during the optimization process. Also the search efficiency and the accuracy of the optimization are compared with another global optimization scheme. At last, this paper gives maximum L/D optimization with restrictions of actual volumetric efficiency and the total mass, which shows that the adaptive surrogate model is quite suitable for the design optimization of waveriders.

Abstract: A novel Fuzzy Logic controller design methodology is presented. The method utilizes a Particle Swarm Optimization (PSO) binary search algorithm to generate the rules for the Fuzzy Logic controller rule-base stage without human experience intervention. The proposed technique is compared with the well established Lyapunov based Fuzzy Logic controller design in generating the rules. Finally, the controller’s effectiveness and performance are tested, verified and validated using an elevator control application. The novel controller’s results are to be compared with traditional Proportional Integral Derivative (PID) controller and classical Fuzzy Logic (FL) controllers.

Abstract: Modeling and simulating of human musculoskeletal system is an important and challenging problem. This paper is aimed to build a computational platform to conquer this problem based on the China digital human project. First the 3D anatomical models of human musculoskeletal system were reconstructed and integrated. Second, the finite element models of human skeleton system were built. In the end, a computational platform, which integrated the models and six related analysis modules, was developed to model and simulate human musculoskeletal system. A case study of subject’s gait was implemented to demonstrate that this computational platform had potential in research of human musculoskeletal biomechanics.

Abstract: Change Ranking of Product Subsystems (CROPS) is a computer program that is designed to act as a decision-making aid for designers during early stages of their product redesign process. It generates a ranking of all subsystems within the existing product design architecture based on their estimated redesign risk. This information assists designers in selecting the right existing subsystems to be initially changed to satisfy the driving requirements, which have to be quickly decided. In this program, evaluation of redesign risk captures both direct and indirect change effects that potentially result from the modification of each subsystem. Designers are provided with a relative reference as to how risky and extensive it is to change one subsystem over the others, which can be useful when they have options to pick between several subsystems to modify for the same redesign requirement.

Abstract: OSEK OS is a very static system. all of the functionality of the system is already defined in the design phase. During Operation, the change of the system functionalities does not occur. Thus, we propose a optimized implementation of the scheduler for OSEK OS based on predictable system features to improve the functionality of the Real-time system.

Abstract: Micro Electro Mechanical Systems (MEMS) based Ultrasonic Transducers presents several advantages for some applications such as ease of array fabrication, unique thermal manipulation capabilities. Micromachining allows us to miniaturize device dimensions and produce capacitive transducers whose performance is comparable with their piezoelectric counterpart. Computer simulation has been widely used for MEMS based system. The main advantage of computer simulation is to provide design optimization by varying geometry, layer dimension and materials of the device without actual fabrication. This systematic approach can save time and cost of device fabrication and experimentation. In this work, a model of Capacitive Micromachined Ultrasonic Transducer (CMUT) is simulated in COVENTORWARE software. The solver is used to analyze the electrical current flow, voltage and heat and stress distribution in the device. The result is used to predict the temperature and stress as a function of the applied voltage across heating layer. The displacement results are used in the mechanical analysis to predict the mechanical behaviour of the CMUT. Here two different types of dielectric materials Si₃N₄ and Zr0₂ are used. The optimization is performed mainly based on resonant frequency and collapse voltage. Then we use this model as a gas detector (Sensor) to detect gas like Methane.

Abstract: With the emergence of mobile computing and communication, low power device design and implementation have got a significant role to play in VLSI circuit design. Conventional silicon (bulk CMOS) technology couldn‘t overcome the fundamental physical limitations belonging to sub-micro or nanometer region which leads to alternative device technology like Silicon-on-Insulator (SOI) technology. In a fully-depleted FDSOI structure the electrostatic coupling of channel with source/drain and substrate through the buried layer (BL) is reduced. This allows in turn to reduce the minimal channel length of transistors or to relax the requirements on Si film thickness. A generalized compact threshold voltage model for SOI-MOSFET is developed by solving 2-D Poisson‘s equation in the channel region and analytical expressions are also developed for the same. The performance of the device is evaluated after incorporating the short channel effects. It is observed that in SOI, presence of the oxide layer resists the short channel effects and reduces device anomalies such as substrate leakage by a great factor than bulk-MOS. The threshold voltage and current drive make SOI the ultimate candidate for low power application. Thus SOI-MOSFET technology could very well be the solution for further ultra scale integration of devices and improvised performance.

Abstract: The objective of this research is to operate a robot arm via the Internet network, which is called “Telerobot Arm or (TRA)”. The robot arm is connected with a server computer via a parallel port and it is controlled by a client computer via the Internet network by the webcam guidance. The server and client computers are located at different campuses with distance of around 20 kilometers. The whole robot arm is made of plastic. Therefore, it has some limitation to hold a heavy object. The experiments are conducted on three different tasks, which are 1) hold a small box and put it into a small basket, 2) push a bottle of water, and 3) hold a bottle of water. The experiments have given a very attractive result.

Abstract: In this paper we will introduce a new learning approach for curvilinear bipedal walking of Nao humanoid robot using policy gradient method. A policy of walking is modeled by some policy parameters controlling some factors in programmable central pattern generators. A “Programmable” central pattern generator is made with coupled nonlinear oscillators capable to shape their state equations with some training trajectories. The proposed model has many benefits including smooth walking patterns, and modulation during walking to increase or decrease its speed. A suitable curvilinear walk was achieved, which is very similar to human ordinary walking. This model can be extended and used in Nao soccer player both in standard platform and 3D soccer simulation leagues of Robocup competitions to train different types of motions.