Factors Influence Hanoians’ Choice of Non-Motorized Transport Mode to Access Bus Stations

Hanoi’s rapid urbanization has led to a surge in private vehicle ownership, particularly motorcycles, amidst inadequate public transportation infrastructure. Despite government efforts, many still prefer motorized transport, citing mobility and safety concerns, exacerbated by insufficient pedestrian infrastructure. This study examines the motivations behind this reliance on motorized vehicles, particularly motorcycles, in Hanoi. Findings reveal safety and convenience as primary factors driving motorized transport use, especially for accessing bus stations. Economic incentives could promote non-motorized travel and public transport adoption. Policy implications highlight the importance of addressing economic factors and improving access infrastructure to manage motorized vehicle reliance and foster sustainable urban mobility in Hanoi.

Enhanced Fuzzy Logic Control Model and Sliding Mode Based on Field Oriented Control of Induction Motor

In the context of induction motor control, there are various control strategies used to separately control torque and flux. One common approach is known as Field-Oriented Control (FOC). This technique involves transforming the three-phase currents and voltages into a rotating reference frame, commonly referred to as the “dq” frame. In this frame, the torque/speed and flux components are decoupled, allowing for independent control, by doing so, the motor’s speed can be regulated accurately and maintain a constant flux which is crucial to ensure optimal motor performance and efficiency. The research focused on studying and simulating a field-oriented control system using fuzzy control techniques for an induction motor. The aim was to address the issue of parameter variations, particularly the change in rotor resistance during motor operation, which causes the control system to deviate from the desired direction. This deviation implies to an increase in the magnetic flux value, specifically the flux component on the q-axis. By employing fuzzy logic techniques to regulate flux vector’s components in the dq frame, this problem was successfully resolved, ensuring that the magnetic flux value remains within the nominal limits. To enhance the control system’s performance, response speed, and efficiency of the motor, sliding mode controllers were implemented to regulate the current in the inner loop. The simulation results demonstrated the proficiency of the proposed methodology.

Influence of PWM Modes on Commutation Torque Ripples in Sensorless Brushless DC Motor Control System

This paper introduces four PWM modes used in the sensorless brushless DC motor control system, analyzes their different influences on the commutation torque ripple in detail, and selects the best PWM mode in four given types to reduce commutation torque ripple of Brushless OC(BLDC) motors. Simulation and experimental results show that the selection is correct and practical.

Mode switching control strategy of dual motors coupled driving on electric vehicles

Based on analyzing the structure and working principle on electric vehicles （EVs） with dual motors coupled by planetarY gears, the control strategy of mode switching was proposed. The power interruption problem on EVs with automatic mechanical transmission （AMT） shifting was resolved. Based on the speed-torque characteristics of the planetary gears and the principle of the auxiliary motor＇ s zero speed braking, control features of mode switching were introduced. The mode shifting between the main motor mode and dual motors coupled driving were studied. Matlab/Simulink was adopted as a platform to develop the simulation model of EVs with dual motors drive system and 3 gears AMT. Simulation results demonstrated that the power interruption of dual motors drive system was solved during mode switching. The power requirements of EVs were satisfied, too.

Full-order sliding mode control of uncertain chaos in a permanent magnet synchronous motor based on a fuzzy extended state observer

A full-order sliding mode control based on a fuzzy extended state observer is proposed to control the uncertain chaos in the permanent magnet synchronous motor. Through a simple coordinate transformation, the chaotic PMSM model is transformed into the Brunovsky canonical form, which is more suitable for the controller design. Based on the fuzzy control theory, a fuzzy extended state observer is developed to estimate the unknown states and uncertainties, and the restriction that all the system states should be completely measurable is avoided. Thereafter, a full-order sliding mode controller is designed to ensure the convergence of all system states without any chattering problem. Comparative simulations show the effectiveness and superior performance of the proposed control method.

Neural adaptive sliding mode speed tracking control of a DC motor

We propose a BPNN based adaptive sliding mode control scheme for speed tracking of a DC motor with unknown system nonlinearities. The input-output linearization technique is used to cancel the nonlinearities, and output of the BPNN is incorporated into the controller in the proposed scheme. It is shown that the rotor speed of a DC motor can follow any arbitrarily selected trajectories under variable load torque. Then the application of the approach is tested via some simulations.

A Study on the Linear Piezoelectric Motor of Mode Shape

In this paper, we want to make a new type linear piezoelectric motor by mode shape coating or effective electrode surface coating. The mode shape is derived from the mechanical boundary conditions of the linear piezoelectric motor. We only have access to the first three modes of formas, the effective electrode surface coating basis, as well as with the linear piezoelectric motor of normal shape do comparison. Next, we will inspect their gain or axial velocity through theoretical analysis, simulation and experiment. According to the results of the theoretical analysis, we have found that the gain or axial velocity of the linear piezoelectric motors of mode shape is much larger than the linear piezoelectric motors of normal shape. However, according to the results of simulation and experiments, we have found that the gain or axial velocity of the linear piezoelectric motors of mode shape is much greater than the linear piezoelectric motors of normal shape, which is about 1.2 to 1.4 times. The linear piezoelectric motor of mode shape 3 has the fastest axial velocity, which is about -48 mm/s and 48 mm/s under conditions of 180 Vp-p driving voltage, 21.2 kHz driving frequency (the third vibration modal), 25 gw loading and the position of loading or mass at x = 5 mm & 45 mm respectively. And its axial velocity is about 1.4 times the linear piezoelectric motor of normal shape under the same conditions. Overall, the mode shape coating helps to enhance the gain or axial velocity of the linear piezoelectric motor.

Nonlinear Control of an Induction Motor Using a Reduced-Order Extended Sliding Mode Observer for Rotor Flux and Speed Sensorless Estimation

This article proposes an innovative strategy to the problem of non-linear estimation of states for electrical machine systems. This method allows the estimation of variables that are difficult to access or that are simply impossible to measure. Thus, as compared with a full-order sliding mode observer, in order to reduce the execution time of the estimation, a reduced-order discrete-time Extended sliding mode observer is proposed for on-line estimation of rotor flux, speed and rotor resistance in an induction motor using a robust feedback linearization control. Simulations results on Matlab-Simulink environment for a 1.8 kW induction motor are presented to prove the effectiveness and high robustness of the proposed nonlinear control and observer against modeling uncertainty and measurement noise.

Application of Ant Colony Algorithm to the Analysis of Common Mode EMI Model of DC Motor

The Electromagnetic Compatibility (EMC) of direct current (DC) motor windings is a system model which is used to reflect the functional characters of the system in the whole EMC specified frequency (150 KHz ~ 30 MHz). For most motor designing process, it is always used to evaluate the inductance of windings in lower or working frequency;however, when analyzing the conducted interference, it is necessary to take some pa-rameters in high frequency into account in building up the EMC model, such as the noticeable capacitance distributed among the windings or between windings and shells. Past research neglected the common-mode current generated by the high frequency interference within motor bearings coupled with shells, since the parasitic capacitance of rotor core comes from armature windings supplied sufficient paths. In EMC model-ing process for DC motor problem, first, test the impedance of windings by experiments;then, generate the equivalent circuit with overall parameters. At present, it is a difficulty that how to choose the parameters. Most researchers preferred to adopt analytical calculation results, however, it could not reflect the essence of the model since it requires many simplification. Based on this point, this paper adopted ant colony algorithm (ACA) with positive feedback to intelligently search and globally optimize the parameters of equivalent cir-cuit. Simulation result showed that the impedance of equivalent circuit calculated by this algorithm was the same as experimental result in the whole EMC frequency. In order to further confirm the validity of ACA, PSPICE circuit simulation was implemented to simulate the spectrum of common mode Electromagnetic Interference (EMI) of equivalent circuit. The simulation result accords well with the experiment result re-ceived by EMI receiver. So it sufficiently demonstrated correctness of ACA in the analysis of high frequency equivalent circuit.

Three-level inverter configuration with common mode voltage elimination for induction motor drive (To continue)

The multiplicity of vector combinations for vectors of combined three-level inverters plays an important role, when deciding on the modulation scheme, to obtain minimum switching per inverter vector change, as described in the next Section. This is not possible with reduced common-mode three-level inverter structure, obtained with a five-level cascaded H-bridge configuration, as the space vectors locations do not exhibit multiplicity. Moreover, the proposed configuration requires only two power supplies, whereas the scheme with the five-level H-bridge configuration requires six isolated power supplies.

Three-level inverter configuration with common mode voltage elimination for induction motor drive

The multiplicity of vector combinations for vectors of combined three-level inverters plays an important role, when deciding on the modulation scheme, to obtain minimum switching per inverter vector change, as described in the next Section. This is not possible with reduced common-mode three-level inverter structure, obtained with a five-level cascaded H-bridge configuration, as the space vectors locations do not exhibit multiplicity. Moreover, the proposed configuration requires only two power supplies, whereas the scheme with the five-level H-bridge configuration requires six isolated power supplies.

基于改进型滑模变结构的永磁同步电机的无位置传感器矢量控制

针对传统滑模控制采用不连续的符号函数作为滑模面切换函数所引起的抖振问题,提出一种基于改进型滑模变结构的永磁同步电机的无位置传感器矢量控制方法,来削弱抖振,从而改善系统的动、静态性能。首先,设计了改进型滑模控制器和改进型滑模观测器的变结构控制系统。其次,采用连续的开关函数——双曲正切函数作为滑模面切换函数,并通过模糊逻辑控制对双曲正切函数的形状系数进行调整,减弱固定边界层厚度所引起的抖振。然后,运用李雅普诺夫第二定理证明所设计的控制系统的稳定性。最后,与其他方法相比,仿真结果证明了所提方法的可行性和有效性。

A Study on the Mode Shape Piezoelectric Motor

In this paper, we try to use the coating of effective electrode surface and change the direction of polarization to design the mode shape piezoelectric motors of the first three modes. We also com-pare the gain of the mode shape piezoelectric motors with respect to the normal shape piezoelectric motor, including rotational speed, loading ability, torque, phase angle conversion and efficiency. According to the results of theoretical and simulation analysis, we have found that the gain of the mode shape piezoelectric stators are larger than the normal shape piezoelectric stator on average. According to the results of experiments, we found that the gain of the rotational speed, loading ability, torque, driving phase angle conversion and efficiency of the mode shape (MS1 - 3) piezoelectric motors are higher than the normal shape piezoelectric motor (NS) under driving condition of the second vibration mode. Also, the gain of the rotational speed and loading ability of the mode shape 2 (MS2) piezoelectric motor are higher than other shapes piezoelectric motors (NS, MS1 and MS3) under driving condition of the second vibration mode. The used maximum rotational speed of the mode shape 2 (MS2) piezoelectric motor is up to 946 rpm under conditions of 180 Vp-p driving voltage, 10.7 kHz driving frequency, 0o driving phase angle and 13.0 gw net weight. The maximum loading ability and torque of the mode shape 2 (MS2) piezoelectric motor is respectively 451 gw and 0.91 mkgw-m under conditions of 180 Vp-p driving voltage, 10.7 kHz driving frequency, 0o driving phase angle and 173 rpm rotational speed. And the gain of efficiency (output power) and maximum loading ability (torque) of the mode shape 2 (MS2) piezoelectric motor are respectively 2.28 and 1.54 with respect to the normal shape piezoelectric motor under conditions of 180 Vp-p driving voltage, 10.7 kHz driving frequency and 0o driving phase angle. According to the results of the experiments, we have finally found that the piezoelectric motors (NS and MS1 - 3) can be driven only by the second vibration mode because the stator can produce elliptical motion and allows the rotor to generate orientation rotation. However, the first vibration mode can allow the rotor to be rotated very fast but it can’t make the rotation of the rotor orientation. Furthermore, we also found that the rotor can’t rotate by the third vibration mode because its vibration energy is absorbed by the structure itself, so causing the rotor stagnation.

永磁同步电机抗干扰复合滑模控制器的设计

目的 在灌装、封口等包装作业过程中,提高永磁同步电机的快速响应和抗干扰能力,同时减少控制系统的抖振现象。方法 提出一种复合滑模控制策略,设计一种能适应滑模面和系统状态变化的分段速率滑模趋近律,将其与新型积分滑模面结合,设计一种带速度环的滑模控制器。同时,设计一个干扰观测器,用于估计闭环系统的扰动,并将估计后的扰动实时补偿到控制器的输出电流中,构建复合控制器。结果 仿真结果表明,设计的控制器能够显著提高收敛速度,并有效减少了控制系统的抖振,从而提高了动态质量。此外,干扰观测器与控制器结合的复合控制器可以提高系统的抗干扰能力,从而进一步提高了控制性能。结论 文中提出的复合滑模控制策略可以有效提高永磁同步电机调速系统的动态性能,减少控制系统的抖振,为实现高效、稳定的控制提供了有效的解决方案。

Optimization of Bearing Locations for Maximizing First Mode Natural Frequency of Motorized Spindle-Bearing Systems Using a Genetic Algorithm

This paper has developed a genetic algorithm (GA) optimization approach to search for the optimal locations to install bearings on the motorized spindle shaft to maximize its first-mode natural frequency (FMNF). First, a finite element method (FEM) dynamic model of the spindle-bearing system is formulated, and by solving the eigenvalue problem derived from the equations of motion, the natural frequencies of the spindle system can be acquired. Next, the mathematical model is built, which includes the objective function to maximize FMNF and the constraints to limit the locations of the bearings with respect to the geometrical boundaries of the segments they located and the spacings between adjacent bearings. Then, the Sequential Decoding Process (SDP) GA is designed to accommodate the dependent characteristics of the constraints in the mathematical model. To verify the proposed SDP-GA optimization approach, a four-bearing installation optimazation problem of an illustrative spindle system is investigated. The results show that the SDP-GA provides well convergence for the optimization searching process. By applying design of experiments and analysis of variance, the optimal values of GA parameters are determined under a certain number restriction in executing the eigenvalue calculation subroutine. A linear regression equation is derived also to estimate necessary calculation efforts with respect to the specific quality of the optimization solution. From the results of this illustrative example, we can conclude that the proposed SDP-GA optimization approach is effective and efficient.

面内驱动旋转超声电机的研究进展

超声电机利用压电陶瓷的逆压电效应和机械共振来获得其运动和力矩,具有响应快速、定位精度好、可直接驱动等诸多优点,在精密驱动、航空航天、生物医学等领域具有独特的应用优势和成功应用,已有成熟产品实现产业化。基于面内振动模态的微小型超声电机是目前相关研究最易于微小型化的一类,在微机电系统领域具有很好的应用潜力和空间。首先,介绍了超声电机的工作原理;其次,针对夹心式换能器定子结构和贴片式定子结构两种类型面内驱动旋转超声电机,从不同的结构形式、输出性能、应用研究方面归纳总结相关研究的新进展和新成果,比较分析了几种电机样机的主要性能;最后,指出需要深入研究和技术突破的几个问题。

基于ESMDO的级联双模型永磁同步电机鲁棒控制

考虑永磁同步电机调速控制系统中传统电流环数学模型的耦合非线性,结合无模型控制的优势,提出了一种基于扩展滑模观测器(extended sliding mode disturbance observer,ESMDO)的级联双模型永磁同步电机鲁棒控制方法,有效解决了传统PI控制器的鲁棒性差、动态响应慢的问题。首先,在转速环利用传统永磁同步电机数学模型设计了引入自校正开关增益的离散滑模转速控制器,通过离散的ESMDO观测综合扰动项并进行补偿。然后,在考虑电机参数的不确定性和外部扰动的情况下,建立了电流环超局部模型,设计了基于离散的ESMDO的无模型无差拍电流预测控制器。最后,以PI控制为对比方法进行仿真分析,仿真结果表明了所提方法的可行性与有效性。

永磁同步电机新型趋近律滑模控制器设计

针对传统指数趋近律因函数不连续性引起抖振、趋近速度与抖振抑制之间无法同时满足高性能控制系统要求的问题,提出基于系统状态变量的新型滑模趋近律,并应用于永磁同步电机速度、电流控制器中。趋近律引入系统状态变量幂次项和状态变量的双曲正弦值,使系统状态变量以等速和指数2种速率趋向切换面,可以加快系统到达切换面的速度,当系统接近切换面时,指数项接近于0,等速项开始起关键作用,对系统的抖振进行抑制。同时采用双曲正切开关函数替代符号函数,以去除因函数的不连续性所引起的抖振问题。既能提高系统到达滑模面的速度,又能有效抑制固有抖振,提升系统的动态性能。仿真和实验结果表明,新型趋近律相比于传统指数趋近律能够有效降低永磁同步电机启动时转速超调,提高系统的响应速度,抑制系统的抖振。

基于模糊趋近律和扰动观测器的PMSM滑模控制

为了提高永磁同步电机调速系统的响应精度、速度、鲁棒性,解决传统滑模控制中趋于滑模面时间与系统抖振相矛盾的问题,提出了一种基于模糊趋近律和扰动观测器的滑模控制。模糊趋近律根据系统轨迹与滑模切换面的距离来有效地调整切换增益的大小,扰动观测器估计系统的内部参数变化和外部负载干扰,将估计值前馈补偿到速度控制器。仿真结果表明,系统快速跟踪阶跃信号,响应速度加快,系统出现扰动时,电机转速波动极小,迅速恢复稳定时间,结果表明采用基于模糊趋近律和扰动观测器的滑模控制方法能够有效地增强调速系统的鲁棒性和动态性能,并抑制系统的抖振。

基于ESO分数阶滑模调节的PMSM模型预测转矩控制

为了提高永磁同步电机调速系统的性能,提出一种基于扩张状态观测器的分数阶滑模预测转矩控制策略。采用扩张状态观测器对电机的综合扰动项、定子电流和反电动势进行实时观测,可快速准确得到它们的估计值并进行补偿;利用估计值构建分数阶滑模控制器来削弱系统抖振并提高鲁棒性;利用转矩和磁链无差拍预测控制,减少了遍历次数并降低了计算复杂度。通过仿真和半实物平台进行了验证,所得结果表明,所提出的方法能有效提升系统的鲁棒性,使电机具有良好的动态和静态性能。