scholarly journals The control of an active seat with vehicle suspension preview information

2017 ◽  
Vol 24 (8) ◽  
pp. 1412-1426 ◽  
Author(s):  
Abdulaziz Alfadhli ◽  
Jocelyn Darling ◽  
Andrew J Hillis
Keyword(s):  
Objective Function ◽  
Ride Comfort ◽  
Control Method ◽  
Low Frequency ◽  
Experimental Tests ◽  
Cost Effective ◽  
Effective Control ◽  
Vehicle Suspension ◽  
Control Force ◽  
Seat Suspension

This paper presents a novel, simple and reliable control strategy for an active seat suspension, intended for use in a vehicle, which attenuates the harmful low-frequency vertical vibration at the driver’s seat. An advantage of this strategy is that it uses measurable preview information from the vehicle suspension. The control force is calculated from this preview information and controller gains obtained by optimising an objective function using a genetic algorithm (GA) approach. The objective function optimises ride comfort in terms of the Seat Effective Amplitude Transmissibility factor, taking into account constraints on both the allowable seat suspension stroke and actuator force capacity. This new controller is evaluated using both simulation and experimental tests in both the frequency and time domains. The simulation model is based upon a linear quarter vehicle model and a single degree of freedom seat suspension. Experimental tests are performed using a multi-axis simulation table and an active seat suspension. Finally, the performance of the active seat suspension is analysed and compared to a passive system, demonstrating significant acceleration attenuation of more than 10 dB across a broad frequency range. Consequently, this has the potential to improve ride comfort and hence reduce the driver’s fatigue using a reliable and cost-effective control method.

scholarly journals Ride Comfort Control System Considering Physiological and Psychological Characteristics: Effect of Masking on Vertical Vibration on Passengers

Actuators ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 42 ◽  
Author(s):  
Keigo Ikeda ◽  
Ayato Endo ◽  
Ryosuke Minowa ◽  
Takayoshi Narita ◽  
Hideaki Kato
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Ride Comfort ◽  
Control Method ◽  
Vertical Vibration ◽  
Psychological Characteristics ◽  
Psychological State ◽  
Vibration Acceleration ◽  
Seat Suspension ◽  
Vibration Stress

Active seat suspension has been proposed to improve ride comfort for ultra-compact mobility. Regarding the ride comfort of passengers due to vertical vibration, the authors have confirmed from biometry measurements that reduction of the vibration acceleration does not always produce the best ride comfort for passengers. Therefore, heart rate variability that can quantitatively reflect stress is measured in real time, and a control method was proposed that feeds back to active suspension and confirms its effectiveness by fundamental verification. In this paper, we will confirm the influence of the vibration stress on the psychological state of the occupant by the masking method.

scholarly journals Enhancing vehicle suspension system control performance based on the improved extension control

2018 ◽  
Vol 10 (7) ◽  
pp. 168781401877386 ◽  
Author(s):  
Hongbo Wang
Keyword(s):  
Fuzzy Control ◽  
System Performance ◽  
Ride Comfort ◽  
Control Method ◽  
Domain Boundary ◽  
Suspension System ◽  
Vehicle Suspension ◽  
Classical Domain ◽  
Vehicle Suspension System ◽  
Takagi Sugeno

Vehicle suspension system is the key part in vehicle chassis, which has influence on the vehicle ride comfort, handling stability, and security. The extension control, which is not constrained by common control method, could further improve the suspension system performance. The 7 degree-of-freedom suspension model is built. The extension controller is designed according to the function differences. In different extension set domains according to the correlation function, the corresponding control strategy is designed to ensure the suspension system obtains optimal performance in the classical domain and expands the controllable range outside the classical domain as large as possible. By adopting game theory, the domain is optimally divided, and the domain boundary control jump is smoothed by introducing Takagi–Sugeno–Kang fuzzy control into the extension control. Through the simulation and results comparison, it is demonstrated that the extension control could further improve the vehicle ride comfort than the optimal control and the extension control ability can be further promoted through domain game and Takagi–Sugeno–Kang fuzzy control. The analysis of the influence of the extension controller parameter varieties on suspension system performance shows that the error-weighted coefficient and control coefficient have significant effect to the suspension system performance.

Optimal Active Control of Vehicle Suspension System Including Time Delay and Preview for Rough Roads

2002 ◽  
Vol 8 (7) ◽  
pp. 967-991 ◽  
Author(s):  
Javad Marzbanrad ◽  
Goodarz Ahmadi ◽  
Yousef Hojjat ◽  
Hassan Zohoor
Keyword(s):  
Ride Comfort ◽  
Three Dimensional ◽  
Suspension System ◽  
Road Surface ◽  
Vehicle Suspension ◽  
Control Force ◽  
Preview Control ◽  
The Road ◽  
Road Surface Roughness ◽  
Vehicle Suspension System

An optimal preview control of a vehicle suspension system traveling on a rough road is studied. A three-dimensional seven degree-of-freedom car-riding model and several descriptions of the road surface roughness heights, including haversine (hole/bump) and stochastic filtered white noise models, are used in the analysis. It is assumed that contact-less sensors affixed to the vehicle front bumper measure the road surface height at some distances in the front of the car. The suspension systems are optimized with respect to ride comfort and road holding preferences including accelerations of the sprung mass, tire deflection, suspension rattle space and control force. The performance and power demand of active, active and delay, active and preview systems are evaluated and are compared with those for the passive system. The results show that the optimal preview control improves all aspects of the vehicle suspension performance while requiring less power. Effects of variation of preview time and variations in the road condition are also examined.

Enhanced ride comfort using nonlinear seat suspension with high-static-low-dynamic stiffness

2020 ◽  
Vol 51 (4-5) ◽  
pp. 63-76 ◽  
Author(s):  
Chun Cheng ◽  
Yan Hu ◽  
Ran Ma
Keyword(s):  
Ride Comfort ◽  
Structural Parameters ◽  
Dynamic Stiffness ◽  
Damping Ratio ◽  
Low Frequency ◽  
Coupled Model ◽  
Human Model ◽  
Vehicle Speed ◽  
Seat Suspension ◽  
Low Frequency Vibration

To attenuate the low-frequency vibration transmitted to the driver, a nonlinear seat suspension with high-static-low-dynamic stiffness is designed. First, the force and stiffness characteristics are derived. The nonlinear suspension can achieve the quasi-zero stiffness at the static equilibrium position when the structural parameters are properly designed. Then, a car-seat-human coupled model which consists of a quarter car model, a seat suspension, and a 4 degree-of-freedom human model is established to predict the biodynamic response of the driver. Finally, the isolation performance of the high-static-low-dynamic stiffness seat suspension under two typical road excitations is evaluated separately based on the numerical method. The effects of stiffness ratio, damping ratio, and vehicle speed on the ride comfort are investigated. The results showed that the nonlinear seat suspension outperforms the equivalent linear counterpart and can achieve the best ride comfort when the quasi-zero stiffness condition is satisfied.

scholarly journals An active seat suspension design for vibration control of heavy-duty vehicles

2016 ◽  
Vol 35 (4) ◽  
pp. 264-278 ◽  
Author(s):  
Donghong Ning ◽  
Shuaishuai Sun ◽  
Jiawei Zhang ◽  
Haiping Du ◽  
Weihua Li ◽  
...  
Keyword(s):  
Ride Comfort ◽  
Cost Effective ◽  
Basic Structure ◽  
Suspension System ◽  
Heavy Duty ◽  
Linear Motors ◽  
Seat Suspension ◽  
Output Torque ◽  
Hydraulic Cylinders ◽  
Heavy Duty Vehicles

This paper presents the design, fabrication and testing of an innovative active seat suspension system for heavy-duty vehicles. Rather than using conventional linear actuators, such as hydraulic cylinders or linear motors, which need to be well maintained and are always expensive when high force outputs are required, the proposed seat suspension system directly applies a rotary motor in order to provide the required active actuation, without changing the basic structure of the existing off-the-shelf seat suspension. A gear reducer is also applied to amplify the output torque of the motor so that a high output torque can be achieved using a low rated power motor. A static output feedback [Formula: see text] controller with friction compensation is designed to actively reduce seat vibration. Experiments are carried out to test the fabricated suspension prototype. The experimental results show that this type of seat suspension can achieve greater ride comfort in the frequency range of 2–6 Hz than a passive seat suspension. The newly designed active seat suspension is much more cost effective and can be suitable for heavy-duty vehicles.

Sliding Mode Control for Vibration Comfort Improvement of a 7-DOF Nonlinear Active Vehicle Suspension Model

2019 ◽  
Vol 31 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Zhiyong Yang ◽  
Shan Liang ◽  
Yu Zhou ◽  
Di Zhao ◽  
◽  
...  
Keyword(s):  
Sliding Mode Control ◽  
Ride Comfort ◽  
Control Method ◽  
Sliding Mode ◽  
Vehicle Suspension ◽  
Suspension Systems ◽  
Mode Control ◽  
Before And After ◽  
Nonlinear Vibration Control ◽  
Suspension Model

Owing to the presence of nonlinear elements of a vehicle, when the vehicle goes through a rough-road-surface, such as consecutive speed control humps (SCHs), unexpected vibrations will exist in vehicle suspension systems, such as chaos, bifurcation, and quasi-periodic so on. In this paper, we first study the possibility of chaotic vibration of the seven degree-of-freedom (7-DOF) full vehicle model under consecutive SCHs on the highway. Then, a non-chattering sliding mode control method is proposed. The effectiveness of the sliding mode control method for the nonlinear vibration control of the vehicle suspension model is verified by numerical simulation. By comparing the changes in the vibration amplitude of the vehicle in the same velocity region before and after the control, we determine whether the ride comfort is improved. The results show that not only is the system’s chaos vibration effectively controlled, but also the ride comfort is significantly improved. The results can be applied in the design of a vehicle and in pavement of road humps.

Chaos Control of Vehicle Nonlinear Suspension System with Multi-Frequency Excitations by Nonlinear Feedback

2011 ◽  
Vol 55-57 ◽  
pp. 1156-1161
Author(s):  
Jing Yue Wang ◽  
Hao Tian Wang ◽  
Li Min Zheng
Keyword(s):  
Degrees Of Freedom ◽  
Ride Comfort ◽  
Control Method ◽  
Chaotic Behavior ◽  
Time History ◽  
Suspension System ◽  
Vehicle Suspension ◽  
Nonlinear Feedback ◽  
Suspension Model ◽  
Vehicle Suspension System

Vehicle suspension system with hysteretic nonlinearity has obvious nonlinear characteristics, which directly cause the system to the possibility of existence of bifurcation and chaos. Two degrees of freedom for the 1/4 body suspension model is established and the behavior of the system under road multi-frequency excitations is analyzed. In the paper, it reveals the existence of chaos in the system with the Poincaré map, phase diagram, time history graph, and its chaotic behavior is controlled by nonlinear feedback. Numerical simulation shows the effectiveness and feasibility of the control method with improved ride comfort. The results may supply theoretical bases for the analysis and optimal design of the vehicle suspension system.

scholarly journals Symmetry Control of Comfortable Vehicle Suspension Based on H∞

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 171
Author(s):  
Jiguang Hou ◽  
Xianteng Cao ◽  
Changshu Zhan
Keyword(s):  
Ride Comfort ◽  
Control Method ◽  
Output Feedback Control ◽  
Lyapunov Stability Theory ◽  
Active Suspension ◽  
Vehicle Body ◽  
Vertical Acceleration ◽  
Control Force ◽  
Traffic Conditions ◽  
Suspension Model

Suspension is an important part of intelligent and safe transportation; it is the balance point between the comfort and handling stability of a vehicle under intelligent traffic conditions. In this study, a control method of left-right symmetry of air suspension based on H∞ theory was proposed, which was verified under intelligent traffic conditions. First, the control stability caused by the active suspension control system running on uneven roads needs to be ensured. To address this issue, a 1/4 vehicle active suspension model was established, and the vertical acceleration of the vehicle body was applied as the main index of ride comfort. H∞ performance constraint output indicators of the controller contained the tire dynamic load, suspension dynamic stroke, and actuator control force limit. Based on the Lyapunov stability theory, an output feedback control law with H∞-guaranteed performance was proposed to constrain multiple targets. This way, the control problem was transformed into a solution to the Riccati equation. The simulation results showed that when dealing with general road disturbances, the proposed control strategy can reduce the vehicle body acceleration by about 20% and meet the requirements of an ultimate suspension dynamic deflection of 0.08 m and a dynamic tire load of 1500 N. Using this symmetrical control method can significantly improve the ride comfort and driving stability of a vehicle under intelligent traffic conditions.

Screening for resistance of grape varieties to powdery mildew (Erysiphenecator) disease

2015 ◽  
Vol 5 (1) ◽  
pp. 585-590
Author(s):  
Andekelile Mwamahonje ◽  
Deusdedit Kilambo ◽  
Leon Mrosso ◽  
Tileye Feyissa
Keyword(s):  
Powdery Mildew ◽  
Disease Severity ◽  
Control Method ◽  
Cost Effective ◽  
Spore Suspension ◽  
Effective Control ◽  
Grape Vine ◽  
Resistant Varieties ◽  
Significant Difference ◽  
High Level

This study was conducted to evaluate the susceptibility of grapevine varieties to powdery mildew. Powdery mildew is a disease caused by a fungal, Erysiphenecator, and an obligate parasite of grapevine (Vitisvinifera L.). Powdery mildew causes drastic yield losses of 50 to 70%. Commercial grapevines grown in producing countries are susceptible to powdery mildew. Use of fungicides to control the disease is expensive and not environmentally friendly. Therefore, use of grapevine resistant varieties to powdery mildew is cost-effective control method. In this study, ten varieties (Black rose, Regina, Queen of Vineyards, Alphoncelavallee, Makutupora red, Chancellor, Halilibelyji, Syrah, Ruby seedless and Makutupora white) were screened for resistance to powdery mildew, using artificial inoculation of spore suspension and dry inoculums. Infected grape leaves were sampled from the field and grounded to obtain powder which was used as dry inoculum. The spore suspension inoculum was made by mixing powder with sterilized distilled water. The inoculation was done in two blocks with concentration of 2x105 spore/ml. Disease severity was evaluated based on a scale of 0 5; 0, means immune and 5, high level of disease severity. Results showed significant difference (P<0.05) of disease among grape vine varieties evaluated. It was found that 11.1% were resistant, 33.4% tolerant and 55% susceptible to disease. Grapevine variety Chancellor showed the highest level of resistance, and Black rose the most susceptible. The study demonstrates the effectiveness of using inoculation methods in screening resistance to powdery mildew.

Semi Active Seat Suspension System using Modified Intelligent Active Force Control

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
R. Rosli ◽  
Z. Mohamed ◽  
G. Priyandoko
Keyword(s):  
Force Control ◽  
Ride Comfort ◽  
Mr Damper ◽  
Suspension System ◽  
Main Function ◽  
Control Force ◽  
Active Force ◽  
Damping Force ◽  
Seat Suspension ◽  
Active Force Control

This paper presents a modified intelligent active force control (AFC) control strategy in a semi active seat suspension system. The main actuator studied in this research is the Magneto-rheological (MR) damper. Since a semi-active device like MR damper can only dissipate energy so a modified version of AFC controller is needed. The modified AFC controller main function is to determine the appropriate control force. A Heaviside Step Function (HSF) is used to ensure the MR damper produce the desired damping force according to the control force generated by AFC controller. The phenomenological Bouc-Wen is used to study the effectiveness of the new AFC controller taking into account the dynamic response of the damper. Sinusoidal signals simulated as vibration sources are applied to the seat suspension system to investigate the improvement of ride comfort as well as to ascertain the new AFC controller robustness. Comparison of body acceleration signals from the passive suspension with AFC controller semi active seat suspension system shows up to to 45% improvement to the occupant ride comfort under different vibration intensities.

Sign in / Sign up

Export Citation Format

Share Document