TULTECH Journals
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Model Predictive Control for Modeling and Simulation of Human Gait Motions
No full textHuman motion is a complex activity of the central nervous system (CNS) and muscles. Performance of a human motion can be decomposed into three components: estimation of trajectory; calculation of required signal for muscles; and performance of movement. The CNS conducts the first two tasks and the muscles perform the third task. This paper presents the development of a mathematical model and a Matlab Simulink plant for human gait movement. An internal model predictive control (MPC) is setup and plays as the human CNS to estimate the trajectory and to calculate the required signal for muscles to perform the movement. MPC calculates the required torques for each joint and generate optimal trajectories subject to human physical constraints for muscles. Results of simulation are analyzed and compared to the real human gait motions captured by a real motion capture system (Vicon). Finally, conclusions and recommendations from this research are withdrawn
Automated Traffic Law Enforcement System: A Feasibility Study for the Congested Cities of Developing Countries
No full textThe population of the cities in developing countries are growing at a whirlwind speed. Industrialization and urbanization are making the crowd of these countries more city-oriented gradually. Most of these cities were not planned to cope up with a high growth rate of the population. Therefore, congestion occurs with a negative impact on every sector of the lifestyle. Regular traffic congestion in these cities is a remarkable problem which stabilizes the productivity and the national economy as well. An automated traffic enforcement system is not a new concept for any developed territory. But the implementation of such a system in any third world country is the real challenge. Cities like Kabul, Dhaka, Kathmandu, Lusaka, Cairo, Hanoi, Manila etc. are having a huge crowd but very narrow roads and poor traffic maintenance system to regulate those crowds. The transport infrastructure is struggling to keep pace with demand. But before we design any advanced traffic management system, we should look into what are the factors that are causing congestion and how costly are the respective measurements against them. This paper is intended to present a feasibility study on the implementation of the advanced artificial intelligence techniques in the traffic management sectors of the developing countries. It reviews theoretical and empirical work on the determinants on the implementation of automated traffic law enforcement system particularly in the cities of the developing countries
Waveform based Inverse Kinematics Algorithm of Kinematically Redundant 3-DOF Manipulator
No full textThis 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\u27s 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
Ultrasonic based easy parking system based on Microcontroller
No full textThe prime objective of this research is to avoid collision and reliable vehicle parking system. Ultrasonic sensor plays a vital role in grain level filling in a container because fill level is calculated by measuring the distance information. Parking sensor system use either electromagnetic or ultrasonic sensor which alert the driver about the obstacles in the path while parking. Basically, the sensor detects the nearby objects. It will be help in terms of unplanned parking, also one kind of wasting time and wasting fuel. So, in a short time one could easily find a parking slot with low consuming fuel. Principally, drivers are frustrated while waiting for the parking for a longer time. Therefore, this challenge can be possible through the ultrasonic sensor
Application of Gauss - Lanczos Algorithm to Determine Low Modes Density of Dirac Operator
No full textThere are numerous applications in physics, especially in Lattice QCD, where is required to bound entries and the trace of the inverse and the determinant of a large sparse matrix. This paper review one of the most popular methods which are used in lattice QCD to compute the determinant of the lattice Dirac operator: Gaussian integral representation. A modified algorithm can be used for other purposes too, for example for the determination of the density of eigenvalues of the Dirac operator near the origin. This because in Lattice QCD, low-lying Dirac modes are a suitable tool to understand chiral symmetry since they encode the nature of quark propagation as well as the condensate itself in the chiral regime. The formation of a non-zero chiral condensate is an effect of the accumulation of the low modes of the Dirac operator near zero. We review the development in Krylov subspace evaluation of matrix functions and we develop a practical numerical algorithm to achieve a reliable determination of the density of eigenvalues of the Dirac operator near the origin using the Gauss-Lanczos quadrature. We utilize the optimal properties of Krylov subspaces in approximating the distribution of the eigenvalues of the Dirac operator. In this work we have used the Boriçi - Creutz operator to test our method, as an example of using this algorithm in Lattice QCD
Fuzzy Logic Control of Clutch for Hybrid Vehicle
No full textThis 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
Vehicle Steering Dynamic Calculation and Simulation
No full textThis paper presents fundamental mathematical estimations of vehicle sideslip in stationary conditions regarding the influences of the vehicle parameters such as the tire stiffness, the position of gravity centre, the vehicle speed and the turning radius. The vehicle dynamics on steady state and transient responses are also investigated to see the effects of the yaw natural frequency and yaw damping rate on the steering system. Results from this study can be used in designing an automatic control of tracking vehicle in the future
Efficiency Based Comparison of Project Delivery Methods
No full textPublic Private Partnerships (PPP) are the future of infrastructure project delivery. Majority of the PPPs have been successful except a few over the past decade. The reasons for their failure are well documented by researchers. The misconceptions about PPPs make it increasingly difficult to pursue projects using PPP delivery system. One of the root causes of the misconceptions is from the ambiguities arising from qualitative data and assessments. To overcome this issue, efficiency-based comparison of project delivery methods utilizing Data Envelopment Analysis (DEA) for decision making is presented through this paper. Proposed approach uses qualitative ratings and harnesses the integral utility of the ratings obtained while conducting objective assessment of qualitative data. California’s Presidio Parkway Project is used for case study analysis and the data is varied to create three hypothetical scenarios to determine sensitivity of the model. Results from case study are consistent with actual project implementation and the sensitivity analyses result are found to be consistent
Comparing Different DTN Routing Protocols in a Dense Deployment Scenario with Realistic Mobility Trace
No full textIn this paper we propose the usage of Delay Tolerant Networks (DTNs) in dense deployment scenarios where infrastructure access is not available or to reduce the traffic load from congested infrastructure networks for non-time critical applications. The purpose of this paper is to evaluate and compare the performance of different DTN routing protocols in such scenarios where realistic mobility trace is used. The performance is analysed using the metrics of delivery probability, overhead ratio, average latency, average number of hops and average buffer time. The simulation results show that DTN is a good solution to improve the network performance by reducing the traffic load in infrastructure networks and epidemic protocol is the most suitable routing protocol for realistic dense deployment scenarios
Advanced Method for Motion Control of a 3 DOFs Lower Limb Rehabilitation Robot
No full textThis paper presents two motion control methods for a lower limb rehabilitation robot based on compensate gravity proportional-derivative and inverse dynamic proportional-derivative (PD) control algorithms. The Robot’s mechanism is comprised of three active joints: hip joint, knee joint and ankle joint, which are driven by DC motors. Firstly, based on Robot’s mechanism, a dynamic model of the Robot is built. Then, based on Robot’s model, motion control systems for Robot are designed. Simulation results show good performances and workability of these proposed controllers. Finally, the calculation of the joint angle errors and toque of each controller is performed. The comparison of simulation results between proposed controllers and the adaptive fuzzy controller allows to choice suitable motion control methods for Robot that can meet the requirements of a 3 DOFs lower limb rehabilitation robot for post-stroke patient