Minimum Torque Research Articles

Torque Optimization Method of a 3-DOF Redundant Parallel Manipulator Based on Actuator Torque Range

Abstract The small actuator torque range brings advantages for the high-accuracy control of a manipulator. By taking the minimum actuator torque range into account, this paper proposes a novel torque optimization method of a 3-DOF redundantly actuated parallel manipulator for friction stir welding. The dynamic model of the 3-DOF redundant parallel manipulator with four kinematic chains is derived by using the principle of virtual work. The solution of the dynamics is not unique, and the range of four actuator torques constitutes a 4D generalized rectangle. A torque optimization method that minimizes the actuator torque range is presented by determining the generalized 4D rectangle with minimum side length. The proposed optimization method is a global solution corresponding to one trajectory of the moving platform, and it is compared with the least square method which is a local solution corresponding to one pose of the moving platform.

Brushless Wound Rotor Synchronous Machine Based on a Consequent-Pole Rotor Structure with Better Torque Attributes

This paper presents a subharmonic-based brushless wound rotor synchronous machine (BL-WRSM) topology with permanent magnet-assisted (PMA) and consequent-pole (CP) rotor structures to achieve better torque characteristics as compared to the conventional subharmonic-based brushless WRSM. The proposed topologies use the conventional high-efficient subharmonic field excitation technique to achieve a brushless operation and a lower volume of permanent magnet (PM) to achieve better average, starting, maximum, and minimum torques and lower torque ripple. A four-pole, twenty-four-slot (4-pole/24-slot) machine with conventional, PM-assisted (PMA), and consequent-pole (CP) rotor structures are developed in a JMAG-Designer 20.1 environment to carry out two-dimensional finite element analysis (2D-FEA). The developed machines are used to validate the operation and achieve electromagnetic and electromechanical performances of the proposed subharmonic-based BL-WRSM topologies with better torque attributes.

Sensorless based SVPWM-DTC of AFPMSM for electric vehicles

AFPMSM is lighter, has a higher power-to-weight ratio, is shorter in length, is less expensive, and has a higher efficiency than the radial flux motor. Then AFPMSM is more suitable for driving the EV than radial flux motor. The proposed technique in this paper is the sensorless-based SVPWM-DTC of AFPMSM to drive electric vehicles. Sensorless research becomes more important in this circumstance since the axial motor can be placed inside the vehicle tire due to its condensed size and shape similar to the tires. DTC provides less fluctuation for the driver during driving for safety and comfort. SVPWM is preferred for its high performance. When measuring speed using a sensorless estimator, sensor inaccuracy is minimized, and the AFPMS motor can be mounted inside the tire. The control system is tested using two EVs driving cycles, and the results promise high performance. NEDC and HWFET driving cycles are used to test the proposed control scheme in 100 times less than the actual driving cycles’ time to test the coherence of the sensorless estimator. The results demonstrate that the proposed technique is valid for real-time applications with high-performance, minimum torque fluctuations, and minimum transient and steady-state errors.

The fuzzy PD control for combined energy and attitude control system

PurposeThe satellite pointing accuracy plays a crucial role in ensuring a successful satellite mission itself. Therefore, this paper aims to enhance the attitude pointing accuracy of the combined energy and attitude control system (CEACS) in a satellite in the presence of external disturbance torques through a robust controller, which can produce high pointing accuracies with smaller control torques.Design/methodology/approachTo improve the CEACS attitude pointing accuracy, a maiden fuzzy proportional derivative (PD)-based CEACS architecture is proposed. The mathematical models along with its numerical treatments of the fuzzy PD-based CEACS attitude control architecture are presented. In addition, a comparison between the PD and fuzzy PD controllers in terms of the CEACS pointing accuracies and control torques is provided.FindingsNumerical results show that the fuzzy PD controller produces a considerable CEACS pointing accuracy improvement for a lower control torque compartment.Practical implicationsCEACS has gained a renew interest because of significant increase in the projected onboard power requirements for future space missions. Therefore, it is of paramount importance to improve the CEACS pointing accuracy itself with a minimum control torque compartment. In fact, this proposed fuzzy PD controller is shown to be a potential CEACS attitude controller.Originality/valueThe fuzzy PD-based CEACS architecture not only provides a better attitude pointing accuracy but also ensures a lower control torque compartment, which corresponds to a lower onboard power consumption.

Processability and physico‐mechanical properties of ultrahigh‐molecular‐weight polyethylene using low‐molecular‐weight olefin wax

AbstractThe influence of molecular weight of olefin wax as a plasticizer on the processability and properties of ultrahigh‐molecular‐weight polyethylene (UHMWPE) was thoroughly investigated in this study. Two different grades of olefin wax (H5 and 210P) were used separately to plasticize UHMWPE. Comparative results were analyzed based on mixing torque, mechanical, thermal, thermo‐mechanical, and morphological aspects. The Gaussian mathematical model was applied to the internal thermo‐shear batch mixing torque data to predict processability and plasticization of the resulting compounds. A decrease in the peak torque value with increase in wax content revealed the plasticization effect. Across both types of wax (H5 and 210P) at 4, 8, and 10 phr content, the 10 phr H5 wax plasticized UHMWPE batch showed a minimum peak torque of 4.5 Nm with a broad mixing temperature window (∆T) of 32.4°C. The relatively low‐molecular‐weight wax (H5) seemed to be more efficient at uncoiling the entanglements among the amorphous phase of UHMWPE, perhaps because of its smooth interpenetration between ties. The lowest degree of crystallinity range (34%–40%) and the highest nucleation rate (0.9 min−1) were found with 10 phr H5 wax plasticized UHMWPE. The tensile strength of 30.5 MPa and elastic modulus of 127 MPa, achieved by the addition of H5 wax at 10 phr loading, confirmed the optimum effect of plasticization. The plasticization effect was also established from the loss moduli and Cole–Cole plots (log loss modulus vs. log storage modulus). A smaller number of multiple stress‐induced overshoots and the inclining approach toward the viscous dominant regime with temperature sweep were observed in the case of 10 phr H5 wax composition. Scanning electron microscopy (SEM) analysis revealed disappearance of interfacial crazing and interparticle boundaries progressively with the increase in H5 wax content. Overall, plasticized UHMWPE with 10 phr content of H5 wax showed the optimum processability and properties.

Start-up considerations for a small vertical-axis wind turbine for direct wind-to-heat applications

Renewable production of space and water heating is needed for a sustainable society. The rotating shaft of a vertical-axis wind turbine can be equipped with a paddle wheel-style mixing impeller to directly heat a fluid by agitating or stirring the fluid. A Darrieus vertical-axis wind turbine, operating at or near its nameplate power capacity, is able to perform this function reliably as it is producing significant amounts of power; however, an autonomous wind-to-thermal system presents a challenge due to the difficulties associated with the start-up process of this type of turbine. The start-up difficulty is quantified herein by using a set of well-referenced vertical-axis wind turbine start-up data to derive the turbine’s torque and power values for each rotational velocity data point. It is shown that the turbine produces minimal positive torque during an extended region of operation around tip-speed ratio λ=1. A fluid-agitation thermal generator is considered by employing fluid mixing theory to compute the torque of a conceptual mixing impeller for different impeller diameters and styles. A thermal generator impeller is sized based on the derived experimental values and operational characteristics of the vertical-axis wind turbine data set. Thermodynamic analysis for the conceptual fluid-agitation generator shows that for an enclosed fluid volume ▪ = 1L, a fluid temperature rise of approximately ΔT=5°C can be achieved during one hour of system operation. The results demonstrate the potential of H-Darrieus turbines as renewable heat generating devices, while highlighting the need for careful system design to achieve successful start-up.

Proposing a sequential iterative method based on a per-unit model for rotor shape optimization in permanent magnet assisted synchronous reluctance motors

PurposeDuring the design process of synchronous reluctance motors (SynRMs), one crucial step, after its main dimensioning, is optimizing the rotor geometry for maximum average torque and minimum torque ripple. However, because of the complexity of rotor flux-barrier layers geometry, the number of rotor geometrical parameters is high and this step could be quite complex and time-consuming. To obtain a good performance, one needs a robust algorithm to optimize the rotor geometry. The purpose of this paper is to present a sequential iterative method for rotor shape optimization in SynRMs based on the per-unit rotor model to maximize the average torque and minimize the torque ripple.Design/methodology/approachIn the presented method, at first, rotor geometrical parameters are classified into several groups based on their geometrical similarities, and then optimization is done on these individual groups iteratively. The method starts with an arbitrary feasible rotor geometry and proceeds to optimize it. Because the method’s performance depends on initial rotor geometry, different cases are studied to investigate the convergence and robustness of the method. The MATLAB software is used to implement the optimization algorithm, and the ANSYS Maxwell software is used for the finite element analysis.FindingsThe performance of the proposed method is studied on a three-phase 0.75 kW-1,500 rpm permanent magnet assisted SynRM. The results show that the method improves the average torque while reducing the torque ripple. Even if the method starts with an inappropriate initial rotor geometry, it is robust enough and converges within an acceptable number of iterations.Originality/valueThe value of this paper is in introducing a per-unit rotor model. When the authors optimize the rotor geometry for a specific motor rating, it can be scaled up or down for other ratings with little effort. In this work, the number of rotor poles is four and the number of rotor flux-barrier layers per pole is three. Other combinations could be analyzed in future studies.

Unjuk Kerja Performa Turbin Arus Laut Sumbu Vertikal Pada Berbagai Bentuk Sudu Unik

Efficiency and self-starting capability performances are the main problems in vertical axis turbines. By purposing improves its performance, vertical axis turbines have been developed with various models. One of the developments of this model is to design the turbine blades into unique shapes. This research aims to determine the performance of some unique blade vertical axis turbines conditioned on the same parameters, especially if applied in a marine environment. Turbines with helical blade (HB), eggbeater-shaped blade (ESB), diamond-shaped blade (DSB), Y-shaped blade (YSB), and arrow-shaped blade (ASB) were investigated based on efficiency and self-starting capability using QBlade software. Good performance symmetrical foils such as NACA 634021 are also applied to each turbine. The simulation results show that from the aspect of efficiency performance, turbine ASB > HB > ESB > DSB > YSB. Meanwhile, in the aspect of self-starting capability performance, the sequence is similar to efficiency performance, based on the two approaches applied. The highest efficiency achieved by the ASB turbine is 0.391 at the lowest tip speed ratio of λ = 4. The ASB turbine also achieves the best self-starting performance, which has a minimum static torque coefficient of 0.00155 and can produce the required power at the lowest marine current speed of 0.806 m/s. This performance brings the ASB turbine to produce a rated power of 52.52 kW, or more than twice the power production of the lowest efficiency turbine and has an average power gain of 3.75 kW per 0.2 m/s.

Evaluation of the C-lingual Retractor and the Conventional Lingual Orthodontic Brackets in Terms of Speech Performance and Oral Discomfort: A Randomized Controlled Trial.

BackgroundThe C-lingual retractor (CR) is an alternative lingual technique to retract anterior teeth with minimum torque expression loss. Although the effects of lingual braces upon speech and oral comfort have been studied previously, there is no published data about the C-lingual retractor in this aspect. The aims of this trial were to compare (1) speech performance based on objective acoustic analysis and (2) levels of oral impairment between C-lingual retractor and conventional lingual brackets (LBs).Materials and methodsA parallel-group randomized controlled trial was conducted on patients with class II division 1 malocclusion who sought orthodontic treatment at the Department of Orthodontics, Hama University Dental School. Thirty-six patients who met inclusion criteria were randomly selected and divided into two groups. Eighteen patients in the C-lingual retractor group (CR group) were treated with a C-lingual retractor, whereas eighteen patients in the lingual brackets group (LB group) were treated with conventional lingual brackets (Stealth H, American Orthodontics, Sheboygan, WI, USA). Fricative /s/ sound spectrograms were analyzed before (T0), immediately after (T1), one month after (T2), and three months after appliance placement (T3). The levels of oral discomfort were assessed using standardized questionnaires to evaluate speech, irritation, chewing difficulties, and other oral impacts.ResultsAt all assessment times, the C-lingual retractor caused significant deteriorations in articulation, whereas in the lingual brackets group these deteriorations were statistically significant at T1 and T2 (P<0.001) but not significant at T3 (P=0.073). No intergroup differences were detected. Questionnaire analysis revealed that irritation of the tongue was significantly higher in the lingual brackets group after 24 hours of appliances' placement (P=0.007), whereas speech and mastication problems were insignificantly higher in the C-lingual retractor group.ConclusionsThe findings indicate that the C-lingual retractor has insignificantly a little more interaction with sound production than lingual brackets. Although the levels of oral impacts were almost similar among both groups, more tongue irritation was observed in the lingual brackets group. However, the oral discomfort decreased over the observation period in both groups.

Evaluation of lingual fracture pattern of the mandible after bilateral sagittal split osteotomy with and without inferior border osteotomy

The Purpose of the study was to evaluate the pattern of lingual split when performing a bilateral sagittal split osteotomy (BSSO) with different osteotomy methods. A total of 15 dry human cadaveric mandibles was taken for the study. The classical Epker technique of BSSO was performed on the left side. The same was done on the right side along with an-additional inferior border osteotomy. There resultant split was assessed based on modified lingual split scale. The maximum torque force that was needed to split the mandible was recorded and the fracture pattern was observed. Similar osteotomies were performed in 15 fresh goat mandibles which acted as control group. The human cadaveric dry mandible recorded an average torque of 12.6 +2.4 Nm (SD: 0.32) with a maximum of 16.0 Nm and a minimum of 8.0 Nm on left side.80% of the mandible were Type I fracture pattern and 20% had Type III fracture pattern. In contrast with the modified BSSO technique with an additional inferior border osteotomy required a maximal torque of 12.0 N and a minimal torque of 5.0 with an average required torque of 8.7 + 2.1 N on the right side of the mandible.

Optimization design of prosthetic shoulder joint based on three-RRR asymmetric spherical parallel mechanism

<p indent="0mm">Due to its compact spatial layout and good structural stiffness, the three-DOF spherical parallel mechanism has potential advantages in designing multidegree of freedom joints, such as the shoulder and wrist joints. However, existing spherical mechanism design methods do not consider the characteristics of the asymmetric shape of the human shoulder workspace and the asymmetric distribution of dexterous motion ability. Considering the three-RRR asymmetric spherical parallel mechanism as the prototype, this paper investigates the parameter optimization of the prosthetic shoulder joint mechanism to improve the kinematic performance of the asymmetric spherical parallel prosthetic shoulder joint mechanism. First, the parametric model of the mechanism is determined. Based on the derivation of the forward and inverse kinematics solution and the Jacobian velocity matrix, the multiobjective optimization design of the mechanism parameters is with the goal of the maximum coverage of the mechanism workspace to the human shoulder workspace, the maximum dexterity of the mechanism, and the minimum torque of the input shaft. The weight of each index is calculated by the fuzzy analytic hierarchy process based on a triangular fuzzy number, and the optimal mechanism parameters are selected from the Pareto solution set by the weighted summation method. The working space of the bionic shoulder joint mechanism designed according to the optimal mechanism parameters can effectively cover the working space of the human shoulder joint. Compared with the existing parallel mechanisms, its dexterity is improved, and the maximum joint torque is reduced. Thus, this study can provide a theoretical fundament for the design and application of prosthetic shoulder joints.

Mobile robot path planning using fuzzy enhanced improved Multi-Objective particle swarm optimization (FIMOPSO)

This paper introduces a method for car-like mobile robot path planning (CRPP). The robot works in both dynamic and static situations. The aim of this method is to explore the best safe path with minimum path length, minimum motor torque, minimum travel time, minimum robot acceleration and maximum obstacle avoidance. Kinodynamic and non-holonomic constraints related with car-like robot are considered. Fuzzy enhanced Improved Multi-objective Particle Swarm Optimization (FIMOPSO) algorithm is proposed to solve the CRPP problem. Fuzzy inference system is used for obstacle avoidance. In the proposed FIMOPSO, five improvements are made. Proposed technique is compared with Multi-objective Strength Pareto Evolutionary Algorithm 2 (MOSPEA2) technique. Experiments on a custom-made car-like robot are ensuring the quality of proposed technique. This research works show that proposed FIMOPSO is another alternative technique to CRPP problems. Paths dictated by FIMOPSO are safe, collision free, feasible, and possible and can be practically implemented. Fuzzy inference system works well for safe robot travel. FIMOPSO simulation paths are acceptable. Since, the deviation between experiment and simulation is less than 2%.

Optimization of tool geometric parameters for a small fluteless forming tap (FFT)

The small blind internal thread (SBIT) plays a very important role to firmly fastening some functional components on the cover of 3C electronic products. The small internal thread was made in a blind hole using a fluteless forming tap (FFT) without producing chips. However, the four geometric parameters of the FFT (tool width (W), tooth root diameter (D2), front-end diameter (Df), and tooth angle (θ)) will affect the thread filling rate (f) and minimum torque (T) in tapping process. This study reports the Box-Behnken design (BBD), combined with DEFORM-3D (finite element model) and MINITAB (regression analysis) software, to tap 7075-T6 aluminum alloy with small FFT to obtain reliable results of thread filling rate and minimum torque. The experimental results show that the BBD can accurately predict and simulate the thread filling rate of tapping 7075-T6 aluminum alloy. The modeling software and experimental design used in this research are very suitable for the optimal design of the FFT used in industrial production.

Active Fluid-Film Bearing With Deep Q-Network Agent-Based Control System

Abstract Despite the fact that the hydrodynamic lubrication is a self-controlled process, we designed control systems based on proportional integral (PI) controller, adaptive PI controller, and Deep Q network (DQN)-agent to minimize the friction torque in a conical fluid-film bearing. The bearing construction allows the shaft axial displacement and, as the result, the regulation of the bearing average clearance due to the controlled supply pressure. The main challenge is that the friction torque minimization may lead to the loss of load-carrying capacity and the contact in the shaft-bearing tribocouple. The other challenge is that random events may have an influence on the hydrodynamic lubrication parameters, therefore, changing the load-carrying capacity and the friction torque. So, the proposed control systems were designed and tested under the conditions of limited lateral shaft displacements and the action of a random external force. The tests were performed using simulation models of a controlled rotating machine in matlab software. The rotating machine simulation model includes modules of the rigid shaft, the coupling with linear axial reaction, and the conical bearing. The bearing module is based on the numerical solution of the generalized Reynolds equation and its nonlinear approximation with fully connected neural networks. The obtained results demonstrated that the application of an adaptive PI controller or a DQN agent allows decreasing friction torque in a bearing under the conditions of a random external force. The goal of a DQN agent is self-learning in contrast to an adaptive PI controller that needs to be tuned.

What is the minimum torque required to obtain passive elbow end range of motion?

BackgroundPassive range of motion is a common clinical assessment. The point at which passive end range of motion is measured is typically described by the ‘end-feel’of the joint.Research Question: What is the minimum amount of torque required to obtain passive elbow flexion and extension in children? MethodsTwenty-five children (age, 7.5 ± 1.6 years-old), who had previously sustained unilateral distal humeral fractures, participated in this prospective study.Passive elbow flexion and extension was measured at least 8 weeks and up to one year out of cast. Motion capture cameras were used to track twenty-one reflective markers placed on subjects and two markers attached to the pad of a force transducer.Five trials of passive range of motion (flexion and extension) were performed on both arms. Elbow joint moments were calculated as products of the forces applied and lengths to the elbow centers. A one way ANOVA was used to determine differences in moments for flexion and extension for both involved and uninvolved limbs. Pairedsamples t-tests were used to determine differences between the involved and the uninvolved limbs for both maximum flexion and extension. ResultsThere was no difference in the minimum mean joint moment (2.7 ± 1.1 Nm) at end range of motion. However, differences in passive range of motion was found between involved and uninvolved elbows (flexion p < .001; extension p = .001). SignificanceThe results demonstrate therapists obtained end range of passive elbow flexion and extension applying the same amount of minimum torque. A small torque is sufficient to achieve end range of elbow motion for children. This torque can be used in guiding clinical practice for assessing passive range of elbow motion in pediatric population. Because of a paucity of data for any joint, future research developing force data for other joints should be conducted

Analysis and Cogging Torque Minimization of a Novel Flux Reversal Claw Pole Machine with Soft Magnetic Composite Cores

The performances of a novel flux reversal claw pole machine (FRCPM) using soft magnetic composite (SMC) cores is analyzed in detail. The developed FRCPM uses both a flux reversal permanent magnet machine (FRPMM) and claw pole machine (CPM). In this paper, the main dimensions are optimized to ensure that the FRCPM can achieve maximum torque. In addition, the rotor skewing technology applied in the paper leads to a reduction in cogging torque and torque ripple of the machine. The main electromagnetic parameters and performance are obtained using the 3D finite element method.

A Generalized Regression Neural Network Model for Predicting the Curing Characteristics of Carbon Black-Filled Rubber Blends.

In this study, a new generalized regression neural network model for predicting the curing characteristics of rubber blends with different contents of carbon black filler cured at various temperatures is proposed for the first time The carbon black contents in the rubber blend and cure temperature were used as input parameters, while the minimum and maximum elastic torque, scorch time, and optimal cure time, obtained from the analysis of 11 rheological cure curves registered at 10 various temperatures, were considered as output parameters of the model. A special pre-processing procedure of the experimental input and target data and the training algorithm is described. Less than 55% of the experimental data were used to significantly reduce the total number of input and target data points needed for training the model. Satisfactory agreement between the predicted and experimental data, with a maximum error in the prediction not exceeding 5%, was found. It is concluded that the generalized regression neural network is a powerful tool for intelligently modelling the curing process of rubber blends even in the case of a small dataset, and it can find a wide range of practical applications in the rubber industry.

Green compounds of SBR with nanofibrilated cellulose and palm oil in replacement to traditionally compounds used

Silica and carbon black (CB) are the most used reinforcement fillers in elastomeric compositions; however, their obtention and usage might result in environmental and human health damages. The same happens to the plasticizers used in elastomeric compounds, which contain a high content of polycyclic aromatics. To use reinforcement and plasticizer loads from natural sources, the performance of an elastomeric compound by partially replacing CB with nanofibrillated cellulose (CEL) provided with Eucalyptus spp. shavings was evaluated in this work, as well as, the use of palm oil to replace aromatic oils. Nanofibrilated cellulose was obtained by grinding in a micronizing mill. As a characterization of the raw material, the thermal, chemical and morphological properties, as well as particle size analysis of the cellulose suspension were evaluated by the particle size analyzer. From the vulcanized material, the physical, mechanical, dynamic-mechanical properties, cross-link density, and swelling index in solvents were evaluated. As the main results obtained, the presence of CEL clusters seen by scanning electron microscopy with nanofibers with diameters of 100–85 nm was observed. The dynamic light scattering particle size analyzers (DLS) showed nanoparticles from 1 to 100 nm. The rheometric properties showed lower values for the parameters of safety time, optimal vulcanization time, and maximum and minimum torques when compared to samples with CEL as CB. For tear resistance properties, samples with the presence of nanofibrilated cellulose showed 48% more resistance than samples with CB, in the modulus of elasticity, cross-link density, and swelling index, a better performance was also achieved for the samples with CEL, along with presenting a similar behavior in the hardness property between samples with the presence of nanofibrillates and those with CB. Palm oil, a substitute for aromatic oil, was found to be similar in the evaluated properties results, with interaction with CEL, by chemical affinity, which can replace aromatic oil.

A Novel Control Technique Based on Multi-Objective Intelligent Routing Algorithms for Optimum Performances of 12/8 Switched Reluctance Motor

Many objects for better performances in the 12/8 Switched Reluctance Motor (SRM) have been covered in this paper. The idea aimed to a new strategy in the control of this kind of machines for technical improvement by reducing torque ripple with better speed control and economic improvement by reducing the number of switchings. Minimum torque ripple with speed control and minimum number of switchings are the objects that are addressed by combining the Multi-Objectives Particle Swarm Optimization (MO-PSO) algorithm and Hysteresis Current Control (HCC). To achieve the effectiveness of the proposed strategy, the following steps must be taken. The first step is to determine the nonlinear characteristic of 12/8 SRM by Finite Element Method (FEM) for the dynamic model and for the estimation of the instantaneous torque by using the technical look-up table. The second step is the speed control using the SRM by HCC, then pair the MO-PSO with the HCC to determine the optimal parameters for each impact parameters like the turn on, the turn off angles (θon, θoff) and the hysteresis band for the control of the number of switching. Finally, the graphical and the numerical results confirm and approve the effectiveness of the proposed association between intelligent metaheuristic algorithms and the HCC control to improve the technical-economic performance of the 12/8 SRM considering different conditional loads and speeds.

Comparative Analysis of Torque Ripple for Direct Torque Control based Induction Motor Drive with different strategies

ABSTRACT Direct Torque Control (DTC) method is one of the most outstanding and proficient control techniques of the induction motor. The foremost drawback of DTC induction motor drive is high torque pulsation, variable frequency of inverter switching. The main reason of torque pulsation is torque and flux hysteresis band utilised in DTC. DTC method is utilising hysteresis comparators which produce high torque pulsation and unpredictable switching frequency. In this paper, torque ripple analysis of fuzzy logic controller (FLC) based Direct Torque Control (DTC) of three-phase induction motor drive has been discussed. The space vector pulse width modulation (SVPWM) based DTC technique, which operates with the regular switching frequency, helps to solve the fundamental issues of torque pulsation. In addition to this, literature proposes different solutions like a prediction scheme, fuzzy logic controller technique, global minimum torque ripple strategy, constant frequency torque controller (CFTC) Technique, optimal switching instant scheme, duty cycle control scheme, SVPWM DTC for torque ripple reduction. The fuzzy logic controller capabilities for DTC technique are applied with the induction motor (IM) drive for high-performance applications. The simulation results of Conventional DTC, SVPWM DTC, Carrier SVPWM DTC and FLC-DTC method for the induction motor are illustrated. Fuzzy-based DTC technique compared with CSVPWM DTC method and conventional DTC method are presented. The torque ripple of 7.4% for 5 HP induction motor is achieved by FLC-based DTC method. Hardware results for DTC induction motor drive are also demonstrated and discussed. This paper presents improvement in torque ripple reduction with the help of carrier space vector pulse width modulation (CSVPWM) and FLC-based DTC.