Fuzzy Logic Control of Clutch for Hybrid Vehicle: Fuzzy Logic Control of Clutch for Hybrid Vehicle

This paper provides a design of an automatic clutch controller for hybrid electrical vehicle (HEV) using fuzzy logic. The use of fuzzy logic can reduce the difficulty of mathematical modeling of complex systems since fuzzy logic can deal with uncertain and imprecise data and problems which may have several solutions rather than one. Fuzzy logic algorithms for the automatic clutch controller are developed to achieve a smooth and fast engaging transition. Comprehensive simulations for the whole hybrid electrical vehicle are conducted in Matlab 2009a. An experimental test for a real damping clutch is also carried out. Results show that the active regulation of the clutch slipping ration can considerably reduce the vehicle vibration in resonance frequencies. The new system can handle the clutch engagement with low jerk and high comfort

Waveform based Inverse Kinematics Algorithm of Kinematically Redundant 3-DOF Manipulator

This paper presents a new approach to the problem of inverse kinematics by modelling robot arm movements as signals generated from algebra-based solutions. The inverse kinematics of point P(xP,yP) are modelled as sinusoidal functions with mechanical constraints. Unique wave forms occur at each point in the workspace. There are four types of inverse kinematic waves depending on how sinusoidal waves cross the value of mechanical constraints. In terms of tracking the path, the robot's arm produces complex waves that produce the desired movement. Due to mechanical constraints, many points in the workspace have the bandwidth where the signal is produced only at limited intervals from the angular domain. Tracks must be stored at these appropriate intervals, which build bandwidth tunnels, completely from the initial configuration to the final configuration. Simulations will be carried out using 3-DOF series planar robots to track highly complex mathematical curves. With a wave-based approach, the solution of the IK problem can benefit from wave characteristics such as the superposition principle

Rest-to-Rest Attitude Naneuvers and Residual Vibration Reduction of a Finite Element Model of Flexible Satellite by Using Input Shaper

A three-dimensional rest-to-rest attitude maneuver of flexible spacecraft equipped by on-off reaction jets is studied. Equations of motion of the spacecraft is developed by employing a hybrid system of coordinates and Lagrangian formulation. The finite element method is used to examine discrete elastic deformations of a particular model of satellite carrying flexible solar panels by modelling the panels as flat plate structures in bending. Results indicate that, under an unshaped input, the maneuvers induce undesirable attitude angle motions of the satellite as well as vibration of the solar panels. An input shaper is then applied to reduce the residual oscillation of its motion at several natural frequencies in order to get an expected pointing precision of the satellite. Once the shaped input is given to the satellite, the performance improves significantly

ANALISIS DINAMIKA STRUKTUR PADA SISTEM FLEKSIBEL DI ANTARIKSA

Wahana antariksa atau satelit di antariksa merupakan suatu sistem yang fleksibel. Di sini dilakukan analisis ulang pada suatu system fleksibel di antariksa yang selain dipengaruhi olehmedan gravitasi bumi dan gaya orbital, juga dipengaruhi oleh gaya elastik. Sebagai kelanjutan dari analisis yang dilakukan oleh peneliti sebelumnya, dalam analisis ini adanya pengaruh rotasi struktur pada sumbu sendiri terhadap vektor percepatan dalam koordinat lokal yang bertitlk pusat di titik pusat massa benda tidak diabaikan.Selanjutnya dalam analisis ini ditinjau interaksi antara gerak satelit dengan getaran elastik yang dialaminya. Dengan meninjau stabilitasnya. Persamaan yang diperoleh kemudian dilinearkan dengan menganggap bahwa deformasi pada tiap titik generik jauh lebih kecil dari jari-jari. Persamaan inilah yang selanjutnya dianalisis. Ada dua persamaan yang dihasilkan, yaitu persamaan gerak rotasional struktur, dan persamaan modus generik dari dinamika struktur. Kemudian sistem dimodelkan sebagai suatu batang fleksibel yang merupakan penyederhanaan dari struktur satelit dengan panel surya yang secara geomotrik cukup dominan terhadap badan satelit. Pertama-tama ditinjau gerak dalam bidang orbital, dengan menganggap panel surya memiliki sifat struktural yang seragam sepanjang sumbu panjangnya. Selanjutnya ditinjau gerak tiga dimensi secara umum. Simulasi numerik dilakukan untuk mempelajari kondisi ketidakstabilan sebagai fungsi frekuensi modus structural dan kecepatan orbital. Hasil yang diperoleh dibandingkan dengan hasil serupa dalam pustaka

Rest-to-rest attitude maneuvers and residual vibration reduction of a finite element model of flexible satellite by using input shaper, Shock and Vibration

A three-dimensional rest-to-rest attitude maneuver of flexible spacecraft equipped by on-off reaction jets is studied. Equations of motion of the spacecraft is developed by employing a hybrid system of coordinates and Lagrangian formulation. The finite element method is used to examine discrete elastic deformations of a particular model of satellite carrying flexible solar panels by modelling the panels as flat plate structures in bending. Results indicate that, under an unshaped input, the maneuvers induce undesirable attitude angle motions of the satellite as well as vibration of the solar panels. An input shaper is then applied to reduce the residual oscillation of its motion at several natural frequencies in order to get an expected pointing precision of the satellite. Once the shaped input is given to the satellite, the performance improves significantly

Application of empirical mode decomposition method for characterization of random vibration signals

Characterization of finite measured signals is a great of importance in dynamical modeling and system identification. This paper addresses an approach for characterization of measured random vibration signals where the approach rests on a method called empirical mode decomposition (EMD). The applicability of proposed approach is tested in one numerical and experimental data from a structural system, namely spar platform. The results are three main signal components, comprising: noise embedded in the measured signal as the first component, first intrinsic mode function (IMF) called as the wave frequency response (WFR) as the second component and second IMF called as the low frequency response (LFR) as the third component while the residue is the trend. Band-pass filter (BPF) method is taken as benchmark for the results obtained from EMD method

Coupled and Synchronization Models of Rhythmic Arm Movement in Planar Plane

Nonlinear dynamics have become a new perspective on model human movement variability; however, it is still a debate whether chaotic behavior is indeed possible to present during a rhythmic movement. This paper reports on the nonlinear dynamical behavior of coupled and synchronization models of a planar rhythmic arm movement. Two coupling schemes between a planar arm and an extended Duffing-Van der Pol (DVP) oscillator are investigated. Chaos tools, namely phase space, Poincare section, Lyapunov Exponent (LE), and heuristic approach are applied to observe the dynamical behavior of orbit solutions. For the synchronization, an orientation angle is modeled as a single well DVP oscillator implementing a Proportional Derivative (PD)-scheme. The extended DVP oscillator is used as a drive system, while the orientation angle of the planar arm is a response system. The results show that the coupled system exhibits very rich dynamical behavior where a variety of solutions from periodic, quasi-periodic, to chaotic orbits exist. An advanced coupling scheme is necessary to yield the route to chaos. By modeling the orientation angle as the single well DVP oscillator, which can synchronize with other dynamical systems, the synchronization can be achieved through the PD-scheme approach

Modeling of Axial Spring Stiffness in Active Vibration Controlled Drilling

During drilling process, substantial amount of vibration and shock are induced to the drill string. Active vibration controlled drilling is introduced to reduce the vibration and increase the efficiency of drilling process. In this system, two main components that determine the damping coefficient are magnetorheological (MR) damper and spring assembly. Performance of vibration damping system is depending on the viscosity of MR fluid in the damper and spring constant of spring assembly. One of the key issues that are unclear from the design is the correlation between the axial spring stiffness configuration and the damping force which needs to be tuned actively. There has been lack of studies on how the viscosity of MR fluid on the active vibration damper affects the damping stiffness of the whole system. The objective of the project is to extract the correlations for the viscous damping coefficient, equivalent spring stiffness and power input to the system. Simplified vibration model is thus created using Simulink, together with experimental data fed from APS Technology’s in-house team. Inputs of the simulation such as force exerted, mass of mandrel, spring constant and step time are based on the experimental data and can be adjusted to suit different experiments. By having the model, behavior of the system can be studied and analyzed. From the simulation, it is also observed that the relationship between damping coefficient and power input of the system is linear

Zero Distribution of System with Unknown Random Variables Case Study: Avoiding Collision Path

This paper presents the stochastic analysis of finding the feasible trajectories of robotics arm motion at obstacle surrounding. Unknown variables are coefficients of polynomials joint angle so that the collision-free motion is achieved. ãk is matrix consisting of these unknown feasible polynomial coefficients. The pattern of feasible polynomial in the obstacle environment shows as random. This paper proposes to model the pattern of this randomness values using random polynomial with unknown variables as coefficients. The behavior of the system will be obtained from zero distribution as the characteristic of such random polynomial. Results show that the pattern of random polynomial of avoiding collision can be constructed from zero distribution. Zero distribution is like building block of the system with obstacles as uncertainty factor. By scale factor k, which has range, the random coefficient pattern can be predicted