Slip Suppression Sliding Mode Control with Various Chattering Functions

This study presents performance analysis results of SMC (Sliding mode control) with changing the chattering functions applied to slip suppression problem of electric vehicles (EVs). In SMC, chattering phenomenon always occurs through high frequency switching of the control inputs. It is undesirable phenomenon and degrade the control performance, since it causes the oscillations of the control inputs. Several studies have been conducted on this problem by introducing some general saturation function. However, study about whether saturation function was really best and the performance analysis when using the other functions, weren’t being done so much. Therefore, in this paper, several candidate functions for SMC are selected and control performance of candidate functions is analyzed. In the analysis, evaluation function based on the trade-off between slip suppression performance and chattering reduction performance is proposed. The analyses are conducted in several numerical simulations of slip suppression problem of EVs. Then, we can see that there is no difference of employed candidate functions in chattering reduction performance. On the other hand, in slip suppression performance, the saturation function is excellent overall. So, we conclude the saturation function is most suitable for slip suppression sliding mode control

SMC-I with Approach Angle Method for Slip Suppression of Electric Vehicles

This study presents SMC-I (sliding mode control with integral action) with approach angle method applied to slip suppression problem of electric vehicles (EVs). In SMC, chattering phenomenon always occurs through high frequency switching of the control inputs. It is undesirable phenomenon and degrade the control performance, since it causes the oscillations of the control inputs. Several studies have been conducted on this problem by introducing standard saturation function. However, studies about whether saturation function was really best weren\u27 t done so much. Therefore, in this paper, the SMC-I with approach angle method is proposed to improve the performance of chattering reduction and slip suppression. Then, several candidate functions for SMC are selected and both performances are compared with the proposed method. In the performance analysis, evaluation function based on the trade-off between slip suppression performance and chattering reduction performance is also proposed. The analyses are conducted in several numerical simulations of slip suppression problem of EVs

Dither Effect Of Drum Brake Squeal

Bunyi kiut brek kenderaan merupakan pencemaran bunyi jalanraya yang disebabkan oleh getaran yang teraruh daripada geseran. Paras tekanan bunyi dari bunyi kiut adalah lebih tinggi daripada 70 dB dan ia boleh menyebabkan kerosakan pendengaran jikalau pendedahan jangka panjang. Tesis ini menghuraikan penggunaan daya berfrequensi tinggi, biasanya dirujuk sebagai sistem gentaran untuk mengurangkan bunyi kiut brek gelendong. Penggerak piezoseramik digunakan sebagai punca gentaran. Penggunakan sistem gentaran ini telah berjaya mengurangkan paras tekanan bunyi kiut brek gengendang dari 85 dB ke tahap bunyi latar belakang sebanyak 38 dB. Model matematik dengan dua darjah kebebasan telah dibina untuk menyiasat ciri-ciri bunyi kiut brek gelendong dan keberkesanan sistem gentaran pada keadaan yang berlainan. Parameter model matematik ini ditakrif berdasarkan nilai yang diperolehi dari analisis kebolehgerakan yang diukur pada arah normal dan tangen. Model ini kemudiannya disahkan dengan keputusan eksperimen semasa kiut. Keberkesanan sistem gentaran dalam pengurangan bunyi kiut brek gelendong dikaji pada empat frekuensi gentaran yang berlainan pada arah tangen dan juga arah normal. Berdasarkan keputusan berangka, sistem pengentaran adalah lebih berkesan semasa gentaran dikenakan pada arah tangen dan juga semasa frekuensi gentaran yang lebih rendah digunakan. Selain itu, sistem kawalan ini memerlukan daya gentaran yang lebih rendah pada kelajuan yang rendah bagi mengurangkan bunyi kiut. Keputusan ramalan berdasarkan model ini menunjukkan sekaitan yang tinggi dengan keputusan esperimen. Sistem gentaran juga menghasilkan jalur sisi di kiri dan kanan frekuensi kiut pada sebelum bunyi kiut dipadamkan sepenuhnya. Vehicle brake squeal is a typical traffic noise pollution which is caused by friction induced vibration. The sound pressure level of the brake squeal is higher than 70 dB and it can cause hearing damage if long-term exposure. This thesis describes the use of high-frequency excitation force for suppressing drum brake squeal, commonly referred to as dither control. A piezoceramic actuator is used to generate the dither force. The application of dither has successfully quenched the drum brake squeal from 85 dB to background noise level of 38 dB. A bi-axial two DOF mathematical model is developed to investigate the characteristic of drum brake squeal and the effect of dither on drum brake squeal at various operating parameters. The model parameters are defined based on the mobility measurement in both normal and tangential directions. This model is then validated with the measured results during squeal. The effectiveness of dither is investigated in four excitation frequencies in both tangential and radial directions. The numerical results show that dither control is more efficient in tangential direction and during low dither excitation frequency. Besides, at low sliding speed, lower dither force is needed to suppress the brake squeal. The predicted results based on the developed model shows high correlation with the measured results. The existences of dither excite the sidebands of the squeal peak with equal frequency spacing at both sides before complete suppression of the brake squeal

Development of Urban Electric Bus Drivetrain

The development of the drivetrain for a new series of urban electric buses is presented in the paper. The traction and design properties of several drive variants are compared. The efficiency of the drive was tested using simulation calculations of the vehicle rides based on data from real bus lines in Prague. The results of the design work and simulation calculations are presented in the paper

Sliding Mode Control

The main objective of this monograph is to present a broad range of well worked out, recent application studies as well as theoretical contributions in the field of sliding mode control system analysis and design. The contributions presented here include new theoretical developments as well as successful applications of variable structure controllers primarily in the field of power electronics, electric drives and motion steering systems. They enrich the current state of the art, and motivate and encourage new ideas and solutions in the sliding mode control area

Disturbance Observer-based Robust Control and Its Applications: 35th Anniversary Overview

Disturbance Observer has been one of the most widely used robust control tools since it was proposed in 1983. This paper introduces the origins of Disturbance Observer and presents a survey of the major results on Disturbance Observer-based robust control in the last thirty-five years. Furthermore, it explains the analysis and synthesis techniques of Disturbance Observer-based robust control for linear and nonlinear systems by using a unified framework. In the last section, this paper presents concluding remarks on Disturbance Observer-based robust control and its engineering applications.Comment: 12 pages, 4 figure

Advances in Rotating Electric Machines

It is difficult to imagine a modern society without rotating electric machines. Their use has been increasing not only in the traditional fields of application but also in more contemporary fields, including renewable energy conversion systems, electric aircraft, aerospace, electric vehicles, unmanned propulsion systems, robotics, etc. This has contributed to advances in the materials, design methodologies, modeling tools, and manufacturing processes of current electric machines, which are characterized by high compactness, low weight, high power density, high torque density, and high reliability. On the other hand, the growing use of electric machines and drives in more critical applications has pushed forward the research in the area of condition monitoring and fault tolerance, leading to the development of more reliable diagnostic techniques and more fault-tolerant machines. This book presents and disseminates the most recent advances related to the theory, design, modeling, application, control, and condition monitoring of all types of rotating electric machines

Summary of the Modern Wheel Slip Controller Principles

Railway traction vehicles need to transfer high tractive effort from wheels to rails. The task is complicated because the maximum transferable force continuously changes during the train run, and the change can lead to the high wheels slip velocity or slippage. The effects are undesirable and must be prevented if it is possible or at least limited by slip controllers. There have been several slip controllers developed based on different principles with different degree of complexity and efficiency. The paper summarises principles of the slip control methods and brings their overview with the simulation of their behaviour

Passiv damping on spacecraft sandwich panels

For reusable and expendable launch vehicles as well as for other spacecraft structural vibration loads are safety critical design drivers impacting mass and lifetime. Here, the improvement of reliability and safety, the reduction of mass, the extension of service life, as well as the reduction of cost for manufacturing are desired. Spacecraft structural design in general is a compromise between lightweight design and robustness with regard to dynamic loads. The structural stresses and strains due to displacements caused by dynamic loads can be reduced by mechanical damping based on passive or active measures. Passive damping systems can be relatively simple and yet are capable of suppressing a wide range of mechanical vibrations. Concepts are low priced in development, manufacturing and application as well as maintenancefree. Compared to active damping measures passive elements do not require electronics, control algorithms, power, actuators, sensors as well as complex maintenance. Moreover, a reliable application of active dampers for higher temperatures and short response times (e. g. re-entry environment) is questionable. The physical effect of passive dampers is based on the dissipation of load induced energy. Recent activities performed by OHB have shown the function of a passive friction-damping device for a vertical tail model of the German X-vehicle PHÖNIX but also for general sandwich structures. The present paper shows brand new results from a corresponding ESA-funded activity where passive damping elements are placed between the face sheets of large spacecraft relevant composite sandwich panels to demonstrate dynamic load reduction in vibration experiments on a shaker. Several passive damping measures are investigated and compared

Lateral Stability Control of Four-Wheel Independent Drive Electric Vehicles Based on Model Predictive Control

Four-wheel independent drive electric vehicle was used as the research object to discuss the lateral stability control algorithm, thus improving vehicle stability under limit conditions. After establishing hierarchical integrated control structure, we designed the yaw moment decision controller based on model predictive control (MPC) theory. Meanwhile, the wheel torque was assigned by minimizing the sum of consumption rates of adhesion coefficients of four tires according to the tire friction ellipse theory. The integrated simulation platform of Carsim and Simulink was established for simulation verification of yaw/rollover stability control algorithm. Then, we finished road experiment verification of real vehicle by integrated control algorithm. The result showed that this control method can achieve the expectation of effective vehicle tracking, significantly improving the lateral stability of vehicle