System Identification and Lateral Dynamics of the Active Tilt-Controlled Electric Three Wheeler

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Jigneshsinh Sindha ◽  
Basab Chakraborty ◽  
Debashish Chakravarty

Abstract Active tilt control system (ATC) is considered to be a prominent technological advancement in the three wheelers (3Ws), which improves the drive and comfort capabilities of 3W, leading to additional benefits of excellent maneuverability and small track width. An experimental prototype along with its simulation model is developed, to study the impact of the tilt actuation control system (TAS) and active steer (AS) system on the overall drive experience and stability improvement. A steering direct tilt control (SDTC) strategy is implemented on the vehicle, which allows stable operation of the system during the entire drive range. A transfer function (TF) of the TAS is estimated from the measurements on the prototype using the system identification tool. The derived TF is then utilized to investigate the response of the complete vehicle in terms of vehicle trajectory, perceived acceleration and load transfer across the rear wheels during the double lane change (DLC) and constant turn maneuvers. The results of the analysis indicate that the perceived acceleration felt by the driver is up to 45% less than the lateral acceleration along with up to 36% reduction in load transfer across the rear wheels.

2017 ◽  
Vol 40 (5) ◽  
pp. 1435-1446 ◽  
Author(s):  
Shahab Rahimi ◽  
Mahyar Naraghi

Besides lateral instability, one major threat to all ground vehicles, especially SUVs, is the danger of rollover during cornering. A coordination strategy based on fuzzy logic has been devised to coordinate the sub-controls; namely, active steering, active differential, active brake and a novel active roll control system. Independent study of each sub-control as well as an analysis of their inter-relationship has been carried out. The coordination strategy is supposed to resolve the conflict among control targets – which are sideslip regulation, yaw rate tracking, lateral acceleration tracking and roll motion control – all of which are to be done while maintaining the driver’s desired longitudinal acceleration. Thus, a compromise must be reached. Vehicle sideslip angle and yaw rate were considered to be the criteria for lateral stability; and a combination of roll angle, roll rate and lateral load transfer was selected as the criterion for roll stability. The results of simulations on two SUV models in CarSim software indicate that the integrated controller can successfully restore vehicles’ stability in critical condition.


2011 ◽  
Vol 317-319 ◽  
pp. 590-594
Author(s):  
Xian Xing Liu ◽  
Xiao Yan Shao ◽  
Ming Yi Chen

Due to the complex nonlinear coupling characteristics of non-bearing induction motor control system, the basic requirements to maintain the stable operation of the bearingless induction motor is to achieve the decoupling control between electromagnetic torque and radial force, and it is also difficult to design efficient and reliable control system in this field. In this paper, the entire control system is divided into the rotating control system and suspension control system, a control method direct slip linear control based on space vector modulation (DSLC-SVM) is put forward. As to rotating part, because of the direct control of the slip, the flux magnitude deviation and the current total harmonic distortion (THD) can be reduced. As to suspension part, the voltage PWM controlled inverter is adopted to improve the utilization of DC bus voltage and reduce the impact of high harmonics. At last, by comparing the simulation results with traditional control methods, the feasibility and correctness of this method are demonstrated.


Author(s):  
Xingguo Qian ◽  
Chunyan Wang ◽  
Wanzhong Zhao

In the process of preventing rollover, the expected path of the driver to achieve better anti-rollover effect is often ignored, which may lead to the deviation of vehicle from the original path. Aiming at this problem, this paper considers both anti-rollover and path tracking performance, and proposes an integrated controller based on active steering and active braking. On the one hand, it can reduce the lateral acceleration and rollover risk by restraining the front wheel angle as tracking the driver’s expected path. On the other hand, through reasonably distributing the braking force of the four tires, it can offset the additional yaw moment caused by uneven distribution and reduce the impact on vehicle trajectory as the risk of rollover occurs. In addition, an improved index of rollover is put forward to give early warning to the future moment and to prevent rollover accident effectively. Simulation and hardware-in-the-loop test results show that the proposed integrated controller can ensure that the vehicle tracks the expected path well and achieves rollover prevention effectively.


2020 ◽  
Vol 22 (1) ◽  
pp. 6-12
Author(s):  
Nelia Volkova ◽  
◽  
Alina Mukhina ◽  

Abstract. Introduction. The issue of financial risk management of commercial banks is quite relevant today, because the activity of banks is the most risky of all. The presence of risks in banking can lead to unexpected losses, namely the loss of own resources. That’s why for the stable operation of the bank without loss the priority is to assess the financial risks, which is the basis for their further neutralization. Purpose. The purpose of the article is to develop conceptual provisions for assessment financial risks and justifying the need to neutralize them. Results. The article analyzes the impact of risks on the financial stability of a banking institution. The main methods of bank risk assessment are considered. All these include the statistical method, the analytical method, the expert method, the analogue method and the combined method. The necessity of neutralization of financial risks in order to avoid negative consequences is substantiated. Also the methods of bank risks neutralization are considered. It should be noted that these methods of neutralization can not only be used, but also supplement the list with new methods must be done, which in the future will protect the bank from the influence of undesirable factors. A conceptual approach to the assessment and neutralization of financial risks is proposed. This conceptual approach aims to ensure effective assessment of the level of risk with their subsequent neutralization Conclusions. Use of a conceptual approach will allow an effective risk assessment and decision-making to avoid or accept risk. Thanks to using this approach, the banking institution will be able to react swiftly to the presence of financial risks and to prevent the occurrence of negative consequences, which may lead to a violation of the financial stability of the bank.


1989 ◽  
Vol 21 (10-11) ◽  
pp. 1161-1172 ◽  
Author(s):  
M. Hiraoka ◽  
K. Tsumura

The authors have been developing a hierarchical control system for the activated sludge process which consists of an upper level system controlling long-term seasonal variations, a control system of intermediate level aiming at optimization of the process and a control system of lower level controlling diurnal changes or hourly fluctuations. The control system using the multi-variable statistical model is one of the most appropriate control systems based on the modern control theory, for applying the lower level control of the activated sludge process. This paper introduces our efforts for developing the reliable data acquisition system, the control experiments applying the AR-model, one of the statistical models which were conducted at a pilot plant and present studies on the system identification and control at a field sewage treatment plant.


Emerging technologies have always played an important role in armed conflict. From the crossbow to cyber capabilities, technology that could be weaponized to create an advantage over an adversary has inevitably found its way into military arsenals for use in armed conflict. The weaponization of emerging technologies, however, raises challenging legal issues with respect to the law of armed conflict. As States continue to develop and exploit new technologies, how will the law of armed conflict address the use of these technologies on the battlefield? Is existing law sufficient to regulate new technologies, such as cyber capabilities, autonomous weapons systems, and artificial intelligence? Have emerging technologies fundamentally altered the way we should understand concepts such as law-of-war precautions and the principle of distinction? How can we ensure compliance and accountability in light of technological advancement? This book explores these critical questions while highlighting the legal challenges—and opportunities—presented by the use of emerging technologies on the battlefield.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 671
Author(s):  
Jialing Yao ◽  
Meng Wang ◽  
Zhihong Li ◽  
Yunyi Jia

To improve the handling stability of automobiles and reduce the odds of rollover, active or semi-active suspension systems are usually used to control the roll of a vehicle. However, these kinds of control systems often take a zero-roll-angle as the control target and have a limited effect on improving the performance of the vehicle when turning. Tilt control, which actively controls the vehicle to tilt inward during a curve, greatly benefits the comprehensive performance of a vehicle when it is cornering. After analyzing the advantages and disadvantages of the tilt control strategies for narrow commuter vehicles by combining the structure and dynamic characteristics of automobiles, a direct tilt control (DTC) strategy was determined to be more suitable for automobiles. A model predictive controller for the DTC strategy was designed based on an active suspension. This allowed the reverse tilt to cause the moment generated by gravity to offset that generated by the centrifugal force, thereby significantly improving the handling stability, ride comfort, vehicle speed, and rollover prevention. The model predictive controller simultaneously tracked the desired tilt angle and yaw rate, achieving path tracking while improving the anti-rollover capability of the vehicle. Simulations of step-steering input and double-lane change maneuvers were performed. The results showed that, compared with traditional zero-roll-angle control, the proposed tilt control greatly reduced the occupant’s perceived lateral acceleration and the lateral load transfer ratio when the vehicle turned and exhibited a good path-tracking performance.


2020 ◽  
Vol 68 (10) ◽  
pp. 880-892
Author(s):  
Youguo He ◽  
Xing Gong ◽  
Chaochun Yuan ◽  
Jie Shen ◽  
Yingkui Du

AbstractThis paper proposes a lateral lane change obstacle avoidance constraint control simulation algorithm based on the driving behavior recognition of the preceding vehicles in adjacent lanes. Firstly, the driving behavior of the preceding vehicles is recognized based on the Hidden Markov Model, this research uses longitudinal velocity, lateral displacement and lateral velocity as the optimal observation signals to recognize the driving behaviors including lane-keeping, left-lane-changing or right-lane-changing; Secondly, through the simulation of the dangerous cutting-in behavior of the preceding vehicles in adjacent lanes, this paper calculates the ideal front wheel steering angle according to the designed lateral acceleration in the process of obstacle avoidance, designs the vehicle lateral motion controller by combining the backstepping and Dynamic Surface Control, and the safety boundary of the lateral motion is constrained based on the Barrier Lyapunov Function; Finally, simulation model is built, and the simulation results show that the designed controller has good performance. This active safety technology effectively reduces the impact on the autonomous vehicle safety when the preceding vehicle suddenly cuts into the lane.


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