Torque Control Strategy for High Performance SR Drive

Jin-Woo Ahn 대한전기학회 2008 Journal of Electrical Engineering & Technology Vol.3 No.4

This paper attempts to summarize torque control strategy for high performance SR drive. There are primarily two strategies for torque control. One method is direct torque control, which uses the simple control scheme and hysteresis controller to reduce the torque ripple. Another method is indirect torque control, which uses the complicated algorithms or simple distribution function to distribute each phase torque and obtain current command. The current controller is used to control phase torque by a given current command. In order to compare these two strategies of torque control, five torque control methods are introduced. The advantages and disadvantages of each method are presented. At last, they are verified by some simulations and experimental results.

Torque Control Strategy for High Performance SR Drive

안진우 대한전기학회 2008 Journal of Electrical Engineering & Technology Vol.3 No.4

This paper attempts to summarize torque control strategy for high performance SR drive. There are primarily two strategies for torque control. One method is direct torque control, which uses the simple control scheme and hysteresis controller to reduce the torque ripple. Another method is indirect torque control, which uses the complicated algorithms or simple distribution function to distribute each phase torque and obtain current command. The current controller is used to control phase torque by a given current command. In order to compare these two strategies of torque control, five torque control methods are introduced. The advantages and disadvantages of each method are presented. At last, they are verified by some simulations and experimental results.

Control-oriented modeling and torque estimations for vehicle driveline with dual-clutch transmission

Kim, Sooyoung,Choi, Seibum Elsevier 2018 Mechanism and machine theory Vol.121 No.-

<P><B>Abstract</B></P> <P>Over the years, dual-clutch transmission (DCT) has demonstrated its higher efficiency and superior shift performances over other types of transmissions, and has been increasingly used in modern mass-produced vehicles. However, due to the absence of the smoothing effects of torque converters, vehicles with DCT are easily exposed to driveline oscillations that lead to poor driving quality, especially during gear shifts. Therefore, torque transfer through the driveline should be controlled with great care by two clutches and engine to achieve the DCT's outstanding performance. The main obstacle to the accurate torque control is its lack of adequate sensors in production vehicles. Thus, the objectives of this paper are two-fold. First, a control-oriented model with practical concerns is implemented for DCT drivelines, aiming to accurately describe the powertrain oscillations that should be suppressed by the torque control. Secondly, a real-time torque monitoring strategy based on the proposed model is suggested to deal with the absence of torque sensors. The primary task of the torque estimator is to concurrently estimate the torque transmitted through both clutches and drive shaft by using only readily available data from production cars. The developed torque estimator is verified through multiple experiments under various driving conditions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A control-oriented model for a vehicle driveline with DCT is developed with practical aspects. </LI> <LI> A torque observer is designed to estimate torque through both clutches and the drive shaft in a DCT. </LI> <LI> The observer is based on the control-oriented model and uses data available on production cars. </LI> <LI> The effectiveness of the developed model and the torque observer is demonstrated by experiments. </LI> <LI> The proposed methods of modeling and torque estimation are useful for accurate powertrain controls. </LI> </UL> </P>

Torque Control Strategy for High Performance SR Drive

Ahn, Jin-Woo The Korean Institute of Electrical Engineers 2008 Journal of Electrical Engineering & Technology Vol.3 No.4

This paper attempts to summarize torque control strategy for high performance SR drive. There are primarily two strategies for torque control. One method is direct torque control, which uses the simple control scheme and hysteresis controller to reduce the torque ripple. Another method is indirect torque control, which uses the complicated algorithms or simple distribution function to distribute each phase torque and obtain current command. The current controller is used to control phase torque by a given current command. In order to compare these two strategies of torque control, five torque control methods are introduced. The advantages and disadvantages of each method are presented. At last, they are verified by some simulations and experimental results.

Fastening Torque Control for Robotic Screw Driver under Uncertain Environment

Chwan-Hsen Chen,Wei-der Chong 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

In automatic screw tightening task, the fastening torque and the angular displacement of the screw have to be closely monitored in order to maintain good product quality. Most automatic screw fastening stations use torque sensors to monitoring the fastening process, and traditional strategy in automatic screw fastening is to limit the maximum value of the fastening toque. However, recent studies show that the relation between the fastening torque and the thread-in depth can be utilized to justify the fastening quality, especially for multi-layered workpiece screw fastening and for self-tapping screws. In order to identify the above-mentioned torque-depth pattern and to control the fastening torque and depth at the same time, we propose a servo control system with a disturbance observer to estimate the applied fastening torque without using a torque sensor to measure the fastening torque. The paper reports the formulation of the screw tightening process and the disturbance observer. In the formulation, the reaction torque resulted from fastening can be transformed into an equivalent voltage entering with the control voltage. The disturbance observer, which is based on an augmented model with a dynamic model for the fastening torque, and the model of the screw driver system, can estimate the state variables of the screw driver motor and the fastening torque during screw fastening. The angular displacement of the screw driver is controlled by a state feedback controller, which utilizes the estimated disturbance and states to generate the feedback control input and compensate the reaction torque. A prototyping screw tightening platform is built to test the proposed method. In the experiments, the control system can accurately control the displacement of the rotating tool bit and rapidly estimate the fastening torque with a very short response time.

Comparison of the torque stability of Implant Torque Controllers

Kim, Dae-Gon,Cho, Lee-Ra,Park, Chan-Jin Korean Academy of Dental Science 2009 Journal of korean dental science Vol.2 No.1

Tightening of the screws in implant restorations should be accurate and precise. If applied torque is too low, screw loosening would be occurred. With too high torque, the screw fracture might take place. Various torque generating devices are developed and employed to apply a proper torque. The purpose of this investigation was to determine and compare the accuracy of the torque controllers. In this study, 4 types of torque controllers were used; electronic torque controller, torque limiting device, torque indicating device and contra angle torque driver. Digital torque gauge was employed to measure the de-torque value. Thirty cycles of tightening and loosening were done with each torque controller. All implant torque controllers have shown slight errors and deviations. The torque liming device exhibited the most accurate data. No significant difference was found among the mean de-torque values of the electronic torque controller, torque indicating device and contra angle torque driver. In the limitation of this study, it would be recommended that the implant torque controllers should be checked whether uniformed and precise torque can be generated and a measuring error should be corrected.

MODEL-BASED CONTROL OF ELECTROMAGNETIC VALVE ACTUATORS FOR ENGINE SPEED CONTROL

Huitao Chen,Siqin Chang,Aimin Fan 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.1

The introduction of electromagnetic valve actuators (EMVA) benefits engine fuel economy, torque performance and reduction of emissions. Meanwhile, it complicates the controller for the purpose of regulating the additional freedom degrees of intake valvetrain, such as valve lift, opening timing and opening duration. In order to address the control issue of EMVA application, a model-based controller is needed to realize that the cylinder air charge is regulated by controlling the EMVA motion directly for controlling the engine speed and output torque. For the development of the controller, a control-oriented model of engine with EMVA that can simulate the intake process of unthrottled operation, torque generation and crankshaft rotational dynamics was first developed. Then a model-based EMVA controller was designed to regulate the actuation of electromagnetic intake valves which consisted of a feedforward and a PID feedback module. According to torque-based concept, engine speed reference was translated into torque demand using optimal control theory and the speed control problem was solved as two parts: torque management that decided torque demand and the torque demand tracking. The simulations carried out in Matlab/Simulink verified the effectiveness of the controller. In addition, a test platform of the EMVA for hardware-in-the-loop (HIL) simulation was established and the practicability of EMVA application to engine intake systems was validated preliminarily.

Soft T/F and Transition to Sensorless Control Based on the Torque Angle of a Compressor-Driven IPMSM

Lee Dong-Hee 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.3

This paper presents a soft Torque/Frequency (T/F) starting and transition method to the closed-loop sensorless control of Interior Permanent Magnet Synchronous Motors (IPMSMs) in Electric Vehicle (EV) air-conditioning compressors. The main objective is to enhance the quietness during the starting, stopping, and transition phases from T/F starting to closedloop sensorless control. To achieve this, the paper proposes an instantaneous speed-controlled T/F starting approach based on a torque reference model. Additionally, a torque decline function based on the torque angle is presented for the transition to closed-loop sensorless control. During the starting phase, the proposed T/F model incorporates an ofset starting torque and an accelerating coefcient to the maximum starting torque. As the motor accelerates, the instantaneous torque reference is adjusted to minimize speed ripple and vibrations in the compressor. Once the T/F target speed is reached, the speed is controlled by the T/F angle to minimize current errors. During the transition from T/F starting to closed-loop sensorless control, the reference T/F torque is gradually decreased using an angle error function. This reduction aims to shorten the transition time and ensure a smooth transition with reduced current ripple. By comparing the torque diference, the reference torque in T/F mode rapidly declines to synchronize with the actual rotor position. As a result, the transition occurs with minimized current and speed ripple. The efectiveness of the proposed soft T/F and transition control method for IPMSMs is validated through experiments conducted on a practical Heating, Ventilation, and Air Conditioning (HVAC) system in an EV setting. The experimental results demonstrate that the proposed method efectively reduces mechanical vibrations and achieves smoother transition control, compared to that of the conventional I/F method.

Torque Ripple Reduction in Direct Torque Control of Five-Phase Induction Motor Using Fuzzy Controller with Optimized Voltage Vector Selection Strategy

Hye Ung Shin,Seong Yun Kang,Kyo-Beum Lee 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.3

This paper presents a torque ripple reduction method of direct torque control (DTC) using fuzzy controller with optimal selection strategy of voltage vectors in a five-phase induction motor. The conventional DTC method has some drawbacks. First, switching frequency changes according to the hysteresis bands and motor’s speed. Second, the torque ripple is rapidly increased in long control period. In order to solve these problems, some/most papers have proposed torque ripple reduction methods by using the optimal duty ratio of the non-zero voltage vector. However, these methods are complicated in accordance with the parameter. If this drawback is eliminated, the torque ripple can be reduced compared with conventional method. In addition, the DTC can be simply controlled without the use of the parameter. Therefore, the proposed algorithm is changing the voltage vector insertion time by using the designed fuzzy controller. Also, the optimized voltage vector selection method is used in accordance with the torque error. Simulation and experimental results show effectiveness of the proposed control algorithm.

Torque Ripple Minimization Scheme Using Torque Sharing Function Based Fuzzy Logic Control for a Switched Reluctance Motor

Hak-Seung Ro,Kyoung-Gu Lee,June-Seok Lee,Hae-Gwang Jeong,Kyo-Beum Lee 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.1

This paper presents an advanced torque ripple minimization method of a switched reluctance motor (SRM) using torque sharing function (TSF). Generally, TSF is applied into the torque control. However, the conventional TSF cannot follow the expected torque well because of the nonlinear characteristics of the SRM. Moreover, the tail current that is generated at a high speed motor drive makes unexpected torque ripples. The proposed method combined TSF with fuzzy logic control (FLC). The advantage of this method is that the torque can be controlled unity at any conditions. In addition, the controller can track the torque under the condition of the wrong TSF. The effectiveness of the proposed algorithm is verified by the simulations and experiments.