mohammad saadat

The new generation robots are the ones that have the ability to perform missions in the shortest possible time and with the best performance. In the new generation of quadruped robots, important scientific research topics include stability maintenance, mechanical structure, and control algorithms. The robot climbing the stairs or climbing the stairs is one of the up-to-date and unique topics that has been raised in the field of robotics in a rough way with its own complexity. Jumping the robot from the stairs can be one of the best possible solutions to reduce the time of walking and performing operations. The use of torsion springs as muscles and their location in the joints play an important role in the design of the robot. In this study, the springs at each robot's foot are designed so that the robot can jump using the springs. This has created a unique and unique robot jumping on the stairs, which in itself is one of the most important achievements of this paper. In this research, after designing the four-legged robot and analysing the dynamic equations governing it, the robot is simulated in Adams software. On the other hand, robot jumping has been proposed as the best solution for climbing stairs with specific dimensions and sizes to reach the upper terrace. The result of the simulation shows the acceptable performance of the robot in climbing the stairs.

In this study, the cleaning ability of a stainless-steel rotary instrument called Gentlefile, wascompared with three nickel-titanium rotary instruments.

In this in vitrostudy, forty mandibular single-rooted premolars were randomly assorted into four groups: Gentlefile, ProTper Universal, RaCe files, and XP-Endo Finisher/ProTaper Universal system (n=10). Final instrumentation was done using the aforementioned files with 5.25% sodium hypochlorite and normal saline for root canal irrigation. Debris and smear layers were observed by the scanning electron microscope on the canal walls in the coronal, middle, and apical third of the root level, through a 4-point scoring system. The chi -square test and Kruskal-W allis were used for data analysis.

The Gentlefile demonstrated a promising outcome in smear layer clearance and debris removal compared with the other three rotary systems (P<0.05), specifically at the apical third of the root canal. Based on chi -square test results, there was a significant relationship between root canal cleaning (three levels of cleanliness) in ProTaper Universal (P=0.004) and Gentlefile (P=0.04) groups. Neither of the investigated systems achieved complete cleanliness.

The Gentlefile rotary system can becapable of cleaning the apical third of root canals more than the otherthree groups including Protaper Universal, RaCe, and XP-Endo Finisher

Wheel/rail interaction is one of the most important research topics in railway engineering and generally includes impact response, vibrations, and track safety. Track structure failures caused by wheel/rail impact dynamic forces can lead to significant economic loss through damage to rails, ballast, fastening system, etc. Wheel/rail impact forces occur due to defects in wheels and/or rails such as wheel flats, irregular wheel profiles, rail corrugation, etc. A wheel flat can cause a large dynamic impact force as well as high frequency forced vibrations, which will eventually lead to damage to the train and track structure. In the present work, a freight train (3D model) was used to analyze the dynamic impact caused by the wheel flat using UM software. The effects of wheel flat depth and length (0, 0.2, 0.5, 1, 1.5, 2, and 3 mm) at two speeds of 50 and 80 km/h on wheel/rail dynamic forces have been investigated. The results showed that the presence of a wheel flat defect significantly increases the wheel/rail dynamic impact. For example, by increasing the wheel flat depth to 3 mm, the values of maximum force at speeds of 50 and 80 km/h have changed by about 235% and 400%, respectively.

Increasing the stability of structures and reducing the maintenance cost of slab track superstructures compared to ballasted tracks are among the reasons for the tendency to use this category of superstructures in the railway industry. Vibration reduction methods can be divided into three categories, source, propagation path, and receiver. In general, the slab track structures in Iran are divided into three categories: direct fixation track (DFT), floating slab track (FST), and high resilient fastener (HRF). Although railway tracks are a safe, economical and fast transportation system and can lead to the strengthening of the tourism industry, in the long term, vibrations can damage many historical structures in the city of Isfahan. FST and HRF systems are used in the structure of Isfahan subway track. In this paper, the accelerations (longitudinal, lateral, and vertical) of the Isfahan subway vehicle were measured in 30 stations (15 go stations and 15 return stations). The results showed that the HRF system compared to the FST has a significant effect in reducing the range of vibrations and ultimately the safety of the train and the ride comfort. For example, in the area between Si-O-Se-Pol and Imam Hossein Square, due to the track structure type (HRF), the maximum acceleration and RMS acceleration are in the range of 1.5 and 0.3 m/s2, respectively, while in other stations these values were extracted up to 4 and 0.7 m/s2, respectively.

One of the main problems in sports medicine in today’s world is knee injuries. Champions of various sports fields often suffer from common knee injuries, such as injuries to the anterior cruciate ligament, middle cruciate ligament, medial collateral ligament of the knee, or meniscus. In this paper, a knee brace for general applications is modeled and its stress and strain analysis is calculated with the help of software. First, the displacement of the knee brace with ABAQUS software is investigated. By moving toward the top of the knee brace, the amount of displacement decreases. So that at least the amount of displacement is in the upper part of the knee brace. In the next part, the amount of strain and strain for this knee brace is investigated. The amount of stress in the upper part of the knee brace is higher than in other places. Additionally, the amount of strain for this knee brace is determined, the knee brace in the upper part, on the inner side of the knee brace, bears more strain. The results show that this knee brace can be easily produced and considered for different applications.

The two factors of track irregularity and train speed affect the dynamic behavior of rail vehicles and can lead to an increase in dynamic forces, a decrease in ride comfort, and derailment in some cases. In this paper, the effect of train speed increase and different conditions of track irregularity on ride comfort and ride quality are investigated. For this purpose, first, two freight and passenger train models have been modeled in UM software, and then the effect of train speed increase and track irregularities (different US federal classes) have been studied with Sperling’s index. A freight train with the model of 18-100 and 3-piece bogie and a TGV high-speed train with 10 wagons were simulated. The results showed that in Sperling’s index, with the increase in the train speed and irregularity amplitude, the value of ride comfort and ride quality generally increased. For example, in the passenger train and irregularity classes 5 and 4, with the increase in train speed from 10 to 100 m/s, the Sperling’s index values changed from 0.66 to 1.99 and from 0.78 to 2.25, and increased 200% and 188%, respectively. In other words, at a speed of 10 m/s, passengers' comfort is just noticeable, while at a speed of 100 m/s and class 4, the situation is more pronounced but not unpleasant and the system should be monitored.

Environmental pollution and reduction of fossil fuel resources can be considered as the most important challenges for human society in the recent years. The results of previous studies show that the main consumer of fossil fuels and, consequently, most of the air pollutants, is related to the transportation industry and especially cars. The increasing growth of vehicles, the increase in traffic and the decrease in the average speed of inner-city vehicles have led to a sharp increase in fuel consumption. To address this problem, automakers have proposed the development and commercialization of hybrid vehicles as an alternative to internal combustion vehicles. In this paper, the design of an energy management system in a fuel-cell hybrid vehicle based on the look-ahead fuzzy control is considered. The preparation of fuzzy rules and the design of membership functions is based on the fuel efficiency curve of the fuel-cell. In look-ahead fuzzy control, the ahead conditions of the vehicle are the basis for decision in terms of slope and speed limit due to path curves as well as battery charge level. The fuzzy controller will determine the on or off status of the fuel-cell, as well as the power required. The motion of the fuel-cell hybrid vehicle on a real road is simulated and the performance of the proposed look-ahead controller is compared with the base controller (thermostatic method). The simulation results show that using the proposed approach can reduce the fuel consumption of the fuel-cell hybrid vehicle as well as travel time.

The Qotur metamorphic complex in west of Khoy is consist of various metamorphic rocks including of metabasites, metapelitic and meta-calcareous rocks and serpentinites. The metagabbros form main outcropping rocks in the area. Plagioclase and pyroxene are the main porphyroclasts of metagabbros. Epidote, tremolite/actinolite, calcite and chlorite are formed during low grade metamorphism of these rocks. Based on geochemistry results, protolite compositions of the investigated rocks are plotted on the gabbroic field of the classification diagram. They have calc-alkaline magmatic series. Considering the discrimination tectonic diagrams the Qotur metagabbroic rocks have been formed at the island arc tectonic setting. On the basis of U-Pb zircon geochronological data, the rocks are formed at 162.6±7.6 Ma corresponds to the late Jurassic (Oxfordian). On the basis of results obtained from isotopic dating and geochemical data of the Qotur metagabbros, we suppose that they formed related to the sialic back arc basin of Neotethys, Jurrasic Island arc rocks of Sevan-Akera zone corresponds to the North branch of Neotethys oceanic suture and/or in continuation of the Piranshahr and Serow ophiolites as a Zagros-Bitlis Zone. However perecise results will be need to tectonic works and more geochemical and isotopic data from variety of metamorphic and igneous rocks.

The electric arc furnace (EAF) is one of the popular methods of steel production from steel scraps. The plasma arc is used in EAF to generate heat for melting scarp or direct reduced iron (DRI). The liquid metal is drained from the EAF through the tap hole. Nowadays, it is critical to use Automated/robotic tools for opening the tap hole with oxygen lancing. Because many workers have been blinded by spraying molten particles in opening operation. This study was aimed to simulate a robot manipulator with five degrees of freedom designed for opening the tap hole of an electrical arc furnace. The geometrical model of the robot was designed in Solid works software according to the real workplace and its expected path and obstacles. The Newton-Euler approach was employed to derive the dynamic equations and the resultant joint torques. The dynamic model is used to obtain the operating torques of the joints as well as in the simulation using the SimMechanic toolbox in Matlab software. The results of the simulation with SimMechanic show that the control system can follow the desired path of the robot with acceptable accuracy.

Path planning of mobile robots is one of the important issues in the field of robotics. Also, optimizing the path length and crossing the local minima traps are the basic and up-to-date challenges in this field. One of the important methods in path planning of these robots is the artificial potential field method. Because it is based on simple mathematical calculations. One of the most important disadvantages of this method is getting trapped in local minima situations. One approach for solving the problem of local minima is to use optimization methods to find suitable coefficients (attractive and repulsive) and step length that can solve local minima and optimize the path length. The Harris Hawks algorithm is a powerful and new meta-heuristic algorithm in the field of optimization that is based on population and inspired by the life of Harris Hawks in nature. This algorithm has been able to prove its superiority over similar optimization methods in finding the optimal solution, faster convergence, lower computational time and not trapping in local minima. This method has not been used in the path planning of mobile robots. In order to eliminate the disadvantages of the artificial potential field method and to optimize the path length, the Harris Hawks algorithm has been used in this paper. The simulation results showed that the combination of the artificial potential field method and the Harris Hawks algorithm can solve the local minima problem and optimize the path length, increase the path efficiency and reduce the convergence time.

Reducing the fuel consumption and energy use in transportation systems are the active research areas in recent years. This paper considers the repetitive mission of the intercity passenger buses as a case for fuel reduction. A look-ahead energy management system is proposed which uses the information about the geometry and speed limits of the road ahead. This data can be extracted using road slope and speed limits database in combination with a GPS unit. A fuzzy gain scheduling algorithm is proposed to improve the performance of the look-ahead control. The road slope and speed limit specifications called road pattern can define some two dimensional regions. The main parameters of the proposed fuzzy look-ahead controller are optimized in each region using the genetic algorithm.  The final output of the proposed controller is the desired speed that regularly is fed to the conventional cruise controller with new set points. The simulation results of the proposed energy management system show that the fuel consumption is significantly reduced.

Preparation of proper land use maps has always been one of the important goals of researchers and policymakers. The aim of this study was to provide a new method for preparing land use maps using remotely sensed data and satellite data imagery. For this Purpose, we used Landsat 8 data, Digital Elevation Model (DEM), Principal Component Analysis (PCA), and Spectral Indices to extract land use map in the study area. After all required preprocessing, the training samples were provided. In this study, the training samples were utilized in two parts; in the first part they were used as inputs for image classification using supervised algorithms of maximum likelihood Classification (MLC) and support vector machine (SVM). In the second part, in order to applying Decision Tree Classification (DTC), these training samples were used to determine the spectral reflection of each end-member in the spectrum of electromagnetic waves (image bands, PCA, spectral indices, and DEM).Then, using these binary data and DTC, each end-member was identified and the Landuse/Landcover (LULC) map was extracted. In order to combine the classification results and achieve higher accuracy, the Majority Vote Classification (MVC) method was applied to prepare a new compilation of land use in the area. In order to evaluate the accuracy of produced maps, the statistical parameters extracted from the confusion matrix including overall accuracy, kappa coefficient, user and producer’s accuracy were utilized. According to the results, the combined method (MVC) with a total accuracy of 93.37% and kappa coefficient of 0.91 had the highest accuracy. The overall accuracy of the DTC, SVM, and MLC were 89.61, 88.01 and 87.6%, respectively. Due to the fact that in the nature most of the landuse are mixed and complicated, it would be better to use new methods that cover all aspects of the phenomena. In this research, the data extracted from the supervised classifications as well as the data derived from the DTC were combined and the results clearly illustrate the improvement of the final accuracy of the classification.

The electric arc furnace (EAF) is used to produce high quality steel from steel scraps. The EAF uses plasma arc to generate heat for melting scarp or direct reduced iron (DRI). The liquid metal should be drained from the tap hole. Manual tapping operation of the EAF in the hot environment around the furnace is a potentially dangerous and time consuming task for the workers. Therefore, it is essential to open the tap hole with Automated/robotic oxygen lancing. This study was aimed to design a robot manipulator with five degrees of freedom and revolute joints for opening the tap hole of an electrical arc furnace. The geometrical model of the robot was designed in Solid works software according to real work place and its expected path and obstacles. Direct and reverse kinematic equations were obtained using link parameters (Denawit–Hartenberg) and link transforms. The Newton-Euler approach was employed to derive the dynamic equations and the resultant joint torques.

The Qotur metamorphic complex consists of metabasites, gneisses, marbles and calc-silicates as well as serpentinites which is cropped out at the west border of West Azerbaijan and Turkey. The amphibolites from the Qotur metamorphic complex can be classified as two types of ortho- and para-amphibolites. Minerals in this ortho-amphibolite are hornblende, plagioclase, zircon, titanite, and opaque minerals. The para-amphibolites are characterized by presence of calcite and quartz in addition to amphibole and plagioclase in their mineral assemblages. Tremolite/actinolite, chlorite and sericite are the retrograde phases of the green schist facies. Granoblastic and nematoblastic textures are the common textures of these rocks. Investigation of mineral chemistry and P-T estimations of amphibolites are the aim of this project. Based on electron microprobe analyzes on amphibolites, the amphibole and plagioclase compositions are determined as magnesio-hastengsite and oligoclase, respectively. Plotting of amphibole and titanite compositions on Ti vs. Si and Fe vs. Al diagrams respectively, shows their metamorphic genesis. The thermobarometry results of amphibolites have been obtained on the basis of amphibole and plagioclase compositions as well as utilizing of petrogenetic grids and experimentally determined phase diagrams. The peak metamorphic temperatures and pressures are estimated about 550-650°C and 6-8 Kb. The geothermal gradient is calculated about 25 °C/Km for the obtained temperatures and pressures which corresponds with continental collision conditions. It seems that Cretaceous closure of the Neotethys and its subsequent continental collision during Late Oligocene- Miocene formed the studied amphibolites at the continental crust of the Qotur area.

The outcome of ST-elevation myocardial infarction (STEMI) is significantly influenced by the total tissue ischemic time. In spite of efforts for reducing the in-hospital delay by full-time provision of primary percutaneous coronary intervention (P-PCI) in the 24/7 program, pre-hospital delay still persists. As a first report in Iran, we aimed to assess the duration of pre-hospital delay and its contributing factors in STEMI patients in the P-PCI era. The present cross-sectional study evaluated 2103 STEMI patients who underwent primary PCI from 2016 to 2018. Demographic, personal and socioeconomic factors, index event characteristics, past medical history, pain onset and door times of patients were recorded and independent factors of pre-hospital delay were calculated. Median (IQR) of pain to door (P2D) time was 279 (120-630) minutes. In multivariate analysis, female gender [Beta=0.064 (95%CI: 0.003-0.125); p=0.038], being uneducated [Beta=0.213 (95%CI: 0.115-0.311); p<0.001], the onset of chest pain between 00:00 to 6:00 [Beta=0.130 (95%CI: 0.058-0.202); p<0.001] or 7:00 to 12:00 [Beta=0.119 (95%CI: 0.049-0.190); p=0.001], self-transportation [Beta=0.098 (95%CI: 0.015-0.181); p=0.020] or referral from another hospital [Beta=0.253 (95%CI: 0.117-0.389); p<0.001], atypical chest pain [Beta=0.170 (95%CI: 0.048-0.293); p=0.006], history of hypertension [Beta=0.052 (95%CI: 0.002-0.102); p=0.041], and opium abuse [Beta=0.076 (95%CI: 0.007-0.146); p=0.031] were associated with a significantly higher log(P2D), while history of CABG was associated with shorter P2D. Our study showed that P2D is still very high in Iran and revealed the high-risk groups associated with longer P2D. Effective actions should be implemented to increase the public awareness about the symptoms of STEMI, and the importance of immediate appropriate help-seeking.

Performing primary percutaneous coronary intervention (PPCI) in a timely fashion is a crucial part of the management of ST-elevation myocardial infarction (STEMI). We aimed to evaluate the contributing factors to and the etiologies of a prolonged door-to-device (D2D) time. In 2016, the D2D time was measured in all patients who were treated with PPCI at Tehran Hear Center. The major causes of a prolonged D2D time (>90 min) were determined. The second phase was then started in 2017 by focusing on the determined causes, and direct feedback was given to anyone having contributed to the delayed D2D time. The D2D time was compared between these 2 years. The mean age of the patients was 59.54±11.82 years, and 82.2% of them were men. The median D2D time decreased from 55 minutes (IQR25-75%: 40–82) in 2016 to 46 minutes (IQR25-75%: 34–70) in 2017 (P<0.001). In the first year, 79.8% of the patients had a D2D time of below 90 minutes; the figure rose to 84.1% of the patients in the second year (P=0.017). The first cause of a prolonged D2D time was missed ST-elevation in the first electrocardiogram by physician or nurse (8.4% of the cases). Along with a declining rate of missed STE to 6.7%, the median D2D time in the missed patients also decreased from 205 minutes to 177 minutes (P=0.011). The rate of ambulance arrival increased from 10.2% to 20.7% of the cases, and the median D2D time also declined from 45 (IQR25-75%: 34–55) to 34 (IQR25-75%: 25–55) in these patients (P<0.001). Even in the setting of a 24/7 on-site interventionist in the hospital, the dispatch system and prehospital electrocardiograms, along with regular assessment and feedback, may improve the D2D time.

Hybrid electric vehicles employ a hydraulic braking system and a regenerative braking system together to provide enhanced braking performance and energy regeneration. In this paper an integrated braking system is proposed for an electric hybrid vehicle that include a hydraulic braking system and a regenerative braking system which is functionally connected to an electric traction motor. In the proposed system, four independent anti-lock fuzzy controllers are developed to adjust the hydraulic braking torque in front and rear wheels. Also, an antiskid controller is applied to adjust the regenerative braking torque dynamically.  A supervisory controller, is responsible for the management of this system.  The proposed integrated braking system is simulated in different driving cycles. Fuzzy rules and membership functions are optimized considering the objective functions as SoC and slip coefficient in various road conditions. The simulation results show that the fuel consumption and the energy loss in the braking is reduced. In the other hand, this energy is regenerated and stored in the batteries, especially in the urban cycles with high start/stop frequency. The slip ratio remains close to the desired value and the slip will not occur in the whole driving cycle. Therefore, the proposed integrated braking system can be considered as a safe, anti-lock and regenerative braking system.

Accurate measurement of Mitral Valve Area (MVA) is essential to determining the Mitral Stenosis (MS) severity and to achieving the best management strategies for this disease. The goal of the present study is to compare mitral valve area (MVA) measurement by Continuity Equation (CE) and Pressure Half-Time (PHT) methods with that of 2D-Planimetry (PL) in patients with moderate to severe mitral stenosis (MS). This comparison also was performed in subgroups of patients with significant Aortic Insufficiency (AI), Mitral Regurgitation (MR) and Atrial Fibrillation (AF). We studied 70 patients with moderate to severe MS who were referred to echocardiography clinic. MVA was determined by PL, CE and PHT methods. The agreement and correlations between MVA’s obtained from various methods were determined by kappa index, Bland-Altman analysis, and linear regression analysis. The mean values for MVA calculated by CE was 0.81 cm (±0.27) and showed good correlation with those calculated by PL (0.95 cm, ±0.26 ) in whole population (r=0.771, P

Lower rate of mammography in Iranian women was reported compared to the rates reported from developed countries. Therefore, we aimed to evaluate the rate of mammography in female academics of Tehran University of medical sciences (TUMS) and its influential factors according to Champion health belief model questionnaire.
In this descriptive survey conducted in 2015, the standardized short version of Champion health belief model questionnaire was used to gather information from 99 female academics of TUMS. Further collected data included demographic characteristics of the subjects, past medical history, previous diseases affecting breast and personal knowledge about breast cancer screening.
Among the participants, who were 40 years and older, only 3.7% underwent annual mammography and only 22% of those aged over 45 underwent mammography every three years. Comparison between the two groups according to Champion health belief model revealed significant difference in the mammography benefits and barriers while the scores from susceptibility, severity, breast self-examination (BSE) Barriers, BSE Benefits and BSE Self-Efficacy did not differ significantly between the two groups.
Surprisingly, the rate of mammography among attending physicians of TUMS was found to be similar to the rest of Iranian female population and considerably lower than the figures reported in developed countries.

Asalem metamorphic complex consists mostly of metabasite, metapelite and serpentinite. Metabasites display metamorphic features of greenschist and blueschist facies. Greenschist facies rocks that found as both foliated and massive types contain mineralogical assemblage of actinolite, chlorite, albite and epidote. Blueschists contain mineralogical assemblage of sodic amphibole, epidote and phengite. Whole rock analyses of the metabasites indicate basaltic to andesitic composition with mainly calcalkaline nature of their protolith. According to the discrimination diagrams of tectonomagmatic setting, the protolith of investigated metabasites has been islands arc and somewhat mid ocean ridge. The patterns of rare earth elements and spider diagrams of the Asalem metabasites resemble to the basic and intermediate magmatism of islands arc or suprasubduction setting as well. Greenschists and blueschists facies rocks of the Asalem metamorphic complex have been probably equivalent to islands arc or young and hot oceanic crust of suprasubduction zone setting. This portion of oceanic basin unlike the subducted even and thick oceanic lithosphere of Paleotethys during accretion in the shallower levels of accretionary prisms, have underwent metamorphic conditions of blueschist and greenschist facies and finally gave rise to the formation of the metabasites of the Asalem metamorphic complex.

We aimed to create a shortened form of the Champion Health Belief Model instrument which is a widely used questionnaire about breast cancer screening behaviors with acceptable validity and reliability.
The Persian version of the Champion Health Belief Model (CHBM) instrument consists of 57 items in 8 concepts. The subjects of the study were 40 female faculty members and 34 nurses of Tehran University of Medical Sciences in 2014. Based on the results, the most influential questions in each concept were chosen and then analyzed for internal consistency and the mean scores of the concepts were compared to the original questionnaire. Next, the original form was delivered to a different population. The mean scores of each concept were compared between original and short forms. At last, the same second population was asked to fill in the shortened form in a two-week interval and a test re-test comparison was done.
In the first step, out of 57 items in the original questionnaire, 28 items were selected based on their influence on the mean score of each concept. In 40 female faculty members who were all above 40, all of the Cronbach’s alphas for all subscales were above 0.6 (ranging from 0.624 to 0.830) in the shortened form questionnaire; although they were lower than the original form. There were no significant differences between short and original questionnaires in terms of mean subscale scores. In the second step, in the second population including 34 female nurses aged over forty years in a university medical center, there was again no significant statistical difference between the 28-item and 57-item instruments. In the third step, two weeks later, the completed shortened questionnaire among 20 subjects of the same population of the nurses showed similar results, indicating the reliability of the newly design shortened form of the questionnaire.
The shortened 28-item form of the CHBM instrument seems to be both valid and reliable, and less time-consuming. Its results can be comparable to other studies that used the standard form.

This paper proposes a simple but efficient technique to control 3D overhead crane. Load must track a desired path and not sway more than a reasonable range.The proposed method uses PID control for trolley to track the desired path and fuzzy control compensation to eliminate the load swing. Only the projection of swing angle is applied to design the fuzzy controller. No plant information of crane is necessary in this approach. Therefore, the proposed method greatly reduces the computational efforts. Effectiveness of the proposed method is illustrated through a simulated examp.

A new approach for digital control of a class of nonlinear systems is proposed. For this purpose, a combination of the well-known Parallel Distributed Compensation (PDC) method, and a particular linear digital redesign approach, namely, the plant-input mapping (PIM) method, is employed. In this methodology, a group of linear continuous-time controllers for fuzzy blending using the PDC method is designed and using the PIM method, every linear controller is discretised using the PIM method, with a unique property of guaranteeing the closed-loop stability of every subsystem for all non-pathological sampling periods. Closed loop stability of the resulting digital control system is studied, using the second Lyapunov stability theorem, extended for fuzzy-switching systems. The superiority of the resulting nonlinear digital control system is demonstrated through an example.