Journal of Majlesi Journal of Mechatronic Systems
Volume:1 Issue: 3, Sep 2012

Rehabilitation is one of the non-medical treatments in community health. Rehabilitation means restoration of the abilities to maximize independence. The process of empowering muscles in order to make them to a normal and common value is an expensive and prolonged work. There are some commercial exercise machines used for rehabilitation purposes. However, these machines have limited use because of their insufficient freedom in motion. Hence, it is clearly necessary to use Mechatronic technologies in rehabilitation area. In this paper, an optimized intelligent system is proposed that combines two control strategies: impedance and adaptive control. For optimizing the proposed algorithm, NN and GA tools are used. Then by obtaining the stability conditions, the architecture of rehabilitation system is designed based on these conditions. Finally, the proposed algorithm is implemented on a 2-DOF robot which is attached to the lower limbs of a patient. Thereafter, the results of simulations are presented by defining a physiotherapy standard mode on desired trajectory. MATLAB Simulink is used for simulations.

In this paper two fuzzy LQR controller is designed to control the pitch angle unmanned airship. Airship low altitude can use for monitoring, control and explore and also it can be used to transport and communications objectives considered at high altitude. The results be shown in MATLAB and linear equation of system is used. Compare the results indicates that LQR controller to be more suitable than fuzzy controller to unmanned airship pitch control system.

The objective of this paper is to design a group of nonlinear H∞ controllers for a third-order model of a synchronous generator to attenuate external disturbance. It is supposed that an unknown mechanical perturbation is added to the nominal mechanical power so that drives the power system to an unknown equilibrium point. We will obtain the Hamilton-Jacobi-Isaacs (HJI) inequality related to disturbance attenuation problem of synchronous generator. For this system, HJI inequality is a complex problem to solve and direct solution is hardly reachable as a result, Taylor series approach will be used to solve HJI inequality until fourth order. It will be shown that in addition to stabilization of the system in vicinity of equilibrium point, the controllers also significantly diminish the effect of perturbation and in a limited time drive the states to their nominal values. Simulation results demonstrate the effectiveness and robustness of the nonlinear H∞ controllers.

Capture effect happens when signals transmitted simultaneously from multiple transmitters arrive at the receiver with different power levels; the strongest signal can be successfully received in the presence of collision. This effect can have significant impact on the efficiency of tags’ anti-collision protocols in Radio frequency identification (RFID) systems. A very important issue in the use of capture effect is to adjust the size of the frame in the anti-collision protocols as the capture coefficient. The researchers concluded that the capture coefficient less than 0.2 will not increase the protocol efficiency. In this paper, we show that, according to ISO18000-6C standard, if the time interval is empty, successful and collision slots are considered differently; capture effect with coefficient 0.2 can also increase the efficiency of the protocol. We use DFSA (Dynamic Framed Slotted Aloha) anti-collision protocol to evaluate the proposed method. The experimental results show that our proposed method has better performance than other method.

Precision agriculture is a comprehensive system designed to optimize agricultural production. Using the key elements of information, technology and management, precision agriculture can be used to increase production efficiency, improve product quality and conserve energy. Precision agriculture projects are divided into 2 parts: site specific management (SSM) and postharvest process management (PPM). In present article we used PPM and machine vision technology to sort the tomato into 2 classes. Class A is for fresh using and class B is for processing and making tomato sauce automatically. Knowledge of the physical properties of fruit was necessary. The images of individual tomatoes were captured. Color and textural features of samples were extracted by image processing toolbox of Matlab and were analyzed by statistical software named SPSS. The algorithm was consisted of back ground subtraction, feature extraction and classification. The classification rate was 92% for class A and 100% for class B. The processing speed was 0.67 s.

Flow is one of the most important processes that we have to measure and is widely used in industry. Several ultrasonic flow meters have been offered and fulfilled with different degree of success or lack of success. The purposes of this paper are:•To describe the basic principles underlying approaches to fluid flow measurement and use of ultrasonic transducers in flow metering techniques.•To describe the basic principle of operation of the “sing-around” techniques in ultrasonic systems, along with the criticism of disadvantages of ultrasonic methods.•To introduce novel ultrasonic flow metering approach to use two sing-around paths.By using two sing-around paths with new arrangement, it is possible to mitigate the draw-backs and limitations inherent in conventional ultrasonic flow metering transducers. Salient features of the proposed systems are that the velocity of single-phase fluid flow is independent of fluid sonic velocity, and is directly proportional to the measured parameters concerned. They are bidirectional in operation, and are readily available as clamp-on flow meters for closed types.