SLIDING MODE CONTROL OF ER SEAT SUSPENSION CONSIDERING HUMAN VIBRATION MODEL

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1689-1695 ◽  
Author(s):  
Y. M. HAN ◽  
J. Y. JUNG ◽  
S. B. CHOI ◽  
N. M. WERELEY
Keyword(s):  
Human Body ◽  
Sliding Mode ◽  
Suspension System ◽  
Driver Model ◽  
Ride Quality ◽  
Human Body Model ◽  
Parameter Uncertainties ◽  
Damping Force ◽  
Seat Suspension ◽  
Vibration Model

This paper presents robust control performances of a semi-active electro-rheological (ER) seat suspension incorporating vibration model of human-body. A cylindrical type of ER seat damper is manufactured for a commercial vehicle seat suspension system and its field-dependent damping force is experimentally evaluated. A human-body model is then derived and integrated with the governing equations of the ER seat suspension system. The integrated seat-driver model featured by a high order degree-of-freedom (DOF) is reduced through a balanced model reduction to design robust controller. By imposing semi-active actuating conditions, a sliding mode controller which is very robust to external disturbances and parameter uncertainties is synthesized and experimentally realized with the state observer. In the experimental configuration, a driver directly sits on the controlled seat. Control results for ride quality considering response of each human body segment are evaluated in both time and frequency domains. In addition, a comparison of the proposed semi-active ER seat suspension to a conventional passive seat suspension system is undertaken.

A comparison of different models of passive seat suspensions

2021 ◽  
pp. 095440702199092
Author(s):  
Raj Desai ◽  
Anirban Guha ◽  
P. Seshu
Keyword(s):  
Human Body ◽  
Separate Analysis ◽  
Vehicle Model ◽  
Human Body Model ◽  
Human Comfort ◽  
Vehicle Handling ◽  
Seat Suspension ◽  
Handling Characteristics ◽  
Suspension Model ◽  
Suspension Models

Long duration exposure to vehicle induced vibration causes various ailments to humans. Amongst the various components of the human-vehicle system, the seat suspension plays a major role in determining the level of vibration transferred to humans. However, optimising the suspension for maximising human comfort leads to poor vehicle handling characteristics. Thus, predicting human comfort through various seat suspension models is a widely researched topic. However, the appropriate seat suspension model to be used has not been identified so far. Neither has any prior work reported integrating models of all the components necessary for this analysis, namely human body, cushion, seat suspension and vehicle chassis, each with the appropriate level of complexity. This work uses a two-dimensional 12 DoF seated human body model with inclined backrest support, a nonlinear cushion model, a seat suspension model and a full vehicle model. Two kinds of road profiles – one with random roughness and one with a bump – have been used. It then compares the performance of five different seat suspension models based on a number of human comfort related parameters (seat to head transmissibility, suspension travel, seat acceleration, cushion contact force and head acceleration in both vertical and fore-aft directions) and vehicle handling parameters (vertical, rolling and pitching acceleration of chassis). The results clearly show the superiority of the configuration which involves a spring parallel to an inclined multi-stage damper. A separate analysis was also done to judge whether the integration of the vehicle model (with its associated complication) was necessary for this analysis. A comparison of the human body’s internal forces, moments, acceleration, and absorbed power with and without the vehicle model clearly indicates the need of using the former.

scholarly journals Design of Novel BELBIC Controlled Semi-Active Suspension and Comparative Analysis with Passive and PID Controlled Suspension

2021 ◽  
Vol 18 (5) ◽  
Author(s):  
Pankaj SHARMA ◽  
Vinod KUMAR
Keyword(s):  
Human Body ◽  
Degrees Of Freedom ◽  
Active Suspension ◽  
Driver Model ◽  
Ride Quality ◽  
Body Parts ◽  
Hybrid Techniques ◽  
Design Engineers ◽  
Mass Displacement

Passenger comfort, quality of ride, and handling have broughta lot of attention and concern toautomotive design engineers. These 2 parameters must have optimum balance as they have an inverse effect on each other. Researchers have proposed several approaches and techniques like PID control, fuzzy approach, GA, techniques with inspiration from nature and hybrid techniques to attain the same. A new controller based on the learning behavior of the human brain has been used for the control of semi-active suspension in this study. The controller is known as the Brain Emotional Learning-Based Intelligent Controller (BELBIC). A one-fourth model of car along with the driver model having 6 degrees of freedom (DOF) wasmodeled and simulated. The objective of the studywasto analyze the performance of the proposed controller for improving the dynamic response of the vehicle model coupled with complex biodynamic models of the human body as a passenger, making the whole dynamic system very complex to control. The performance wasanalyzed based on percentage reduction in the overshoot of the vehicle’s sprung mass as well as different human body parts when subjected to road disturbances. The proposed controller performance wascompared with the PID controller, widely used in semi-active suspension. The simulation results obtained for BELBIC controlled system for circular road bump showed that the overshoot of passenger head and body wasreduced by 18.84 and 18.82 %, respectively and reduction for buttock and leg displacement was18.87 %. The vehicle’s seat and sprung mass displacement displayedan improvement of 18.90 and 18.51 %. The overshoot of passenger's head and body displacement wasimproved by 19.79and 19.62 %,respectively, whereas improvement for buttock & leg, vehicle’s seat, and sprung mass displacement were19.81, 20.00, and 20.49 % against trapezoidal speed bump. The PID controlled suspension disclosed an improvement of 8.74, 8.53, 8.75, 11.11, 14.75 % against circular bump and 10.72, 10.33, 10.73, 11.11 and 11.75 % against trapezoidal bump for overshoot reduction of passenger head, body, buttock & leg, vehicle’s seat and sprung mass displacement, respectively. The proposed BELBIC controlled semi-active suspension outperformed the widely used PID controlled semi-active suspension and indicated asignificant improvement in the ride quality of the vehicle.

Design and analysis of an integrated sliding mode control–two-point wheelbase preview strategy for a semi-active air suspension with stepper motor-driven gas-filled adjustable shock absorber

2018 ◽  
Vol 232 (9) ◽  
pp. 1194-1211 ◽  
Author(s):  
Jing Zhao ◽  
Pak Kin Wong ◽  
Xinbo Ma ◽  
Zhengchao Xie
Keyword(s):  
Sliding Mode Control ◽  
Shock Absorber ◽  
Sliding Mode ◽  
Single Point ◽  
Rear Wheel ◽  
Suspension System ◽  
Stepper Motor ◽  
Damping Force ◽  
Mode Control ◽  
Air Suspension

This article proposes an integrated sliding mode control–two-point wheelbase preview strategy for semi-active air suspension system with gas-filled adjustable shock absorber. First of all, a vehicle suspension model with rolling lobe air spring and gas-filled adjustable shock absorber is built, following with a road input model for the front wheel. By describing the detailed structure and working process of the gas-filled adjustable shock absorber, the regulating mechanism between the stepper motor and the designed gas-filled adjustable shock absorber is established. Subsequently, the sliding mode control algorithm is applied to generate the desired damping force with the real-time state of the vehicle. Moreover, to predetermine the road profile for the rear wheel, a two-point wheelbase preview approach is proposed and its superiority is also illustrated as compared with the conventional single-point wheelbase preview approach. To evaluate the performance of the proposed system, numerical analysis is conducted with other three comparative schemes, namely, passive suspension system, active suspension system with H infinity control, and sliding mode control–controlled semi-active air suspension system with adjustable shock absorber. Simulation results show that the integrated sliding mode control–two-point wheelbase preview strategy can be successfully utilized in the semi-active air suspension system with stepper motor-driven gas-filled adjustable shock absorber, and the vehicle performance with the proposed system can be greatly improved.

A sky-hook sliding mode semiactive control for commercial truck seat suspension

2020 ◽  
pp. 107754632094097
Author(s):  
Qiang Chen ◽  
Yong Zhang ◽  
Chengwei Zhu ◽  
Jinbo Wu ◽  
Ye Zhuang
Keyword(s):  
Nonlinear System ◽  
Phase Portrait ◽  
Control Method ◽  
Reference Model ◽  
Sliding Mode ◽  
Tracking Error ◽  
Magnetorheological Damper ◽  
Nonlinear Controller ◽  
Parameter Uncertainties ◽  
Seat Suspension

A semiactive seat suspension control method is proposed in this study and applied to attenuate the vibration of the commercial truck seat for enhancing its ride comfort. The semiactive seat suspension system with a magnetorheological damper behaves with undesirable nonlinear properties. The proposed controller is a typical nonlinear controller, which takes the ideal sky-hook controller as the reference model and forces the tracking error vector. The controller has achieved great performance of attenuating vibration and is robust to parameter uncertainties and external disturbances. The relaxation oscillation phenomenon and convergence were also analyzed by the contribution of the phase portrait. As the phase portrait depicted, the sky-hook controller, a weakly nonlinear system, could be approximated by the equivalent linear approximate model. However, the proposed controller, the sky-hook sliding mode controller, is a strongly nonlinear system, which could not be linearized by the regular perturbation theory, and the criterion is given by the phase portrait. The experiment results showed good agreement with the simulation results, and some other matters encountered were also analyzed in the process of application.

Evaluation of vehicles’ active seat suspension system using wavelet analysis

2020 ◽  
Vol 51 (10) ◽  
pp. 176-185
Author(s):  
Andrzej Błażejewski ◽  
Sebastian Głowiński
Keyword(s):  
Transfer Function ◽  
Wavelet Analysis ◽  
Human Body ◽  
Human Head ◽  
Suspension System ◽  
Test Stand ◽  
Seat Suspension ◽  
System Output ◽  
Vehicle Seat

In this work, the dedicated test stand was applied to investigate the human body–vehicle seat system. The particular signals were measured by accelerometers placed on the seat and the human head. The horizontal vibrations were applied as the input to the system. As an alternative to the classical Fourier approach, the wavelet transfer function was introduced to describe the effectiveness of particular seat suspension. The human head reaction was investigated as the system output.

State estimation and damping control for unmanned ground vehicles with semi-active suspension system

2019 ◽  
Vol 234 (5) ◽  
pp. 1361-1376
Author(s):  
Taipeng Wang ◽  
Sizhong Chen ◽  
Hongbin Ren ◽  
Yuzhuang Zhao
Keyword(s):  
Kalman Filter ◽  
Feedback Linearization ◽  
Sliding Mode ◽  
Suspension System ◽  
Estimation Accuracy ◽  
Sliding Mode Controller ◽  
Damping Force ◽  
Car Suspension ◽  
Linear Observer ◽  
Suspension Model

The new type of transportation based on intelligent driverless vehicles will bring great changes to people’s travel modes and put forward higher requirements for the ride comfortability of vehicles. This paper presents a new observing algorithm to estimate the suspension states in real time and cooperate with sliding mode controller to improve the ride comfortability. First, the nonlinear model of an air suspension system equipped with a continuously controllable damper is described in detail. Then, this nonlinear suspension model is linearized precisely based on the differential geometry theory; a linear Kalman filter observer is implemented for this linearized model; through the coordinate reverse transformation, the designed linear observer is transformed into a nonlinear one, which will be suitable for the original nonlinear system, so that, the proposed state observer can estimate all the states of the nonlinear quarter car suspension system. Then, in this nonlinear suspension system, a model reference sliding mode controller is designed to continuously control the damping force to improve the ride comfortability. Finally, the effectiveness and advantage of the proposed feedback linearization Kalman observer is illustrated by comparing with a traditional extended Kalman filter observer. The simulation research shows that the proposed feedback linearization observer enjoys a better estimation accuracy, higher operation efficiency, and greater control performance while cooperating with the sliding mode controller in ride comfortability control.

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