scholarly journals Comfort Level Refinement of Military Tracked Vehicle Crew through Optimal Control Study

2018 ◽  
Vol 68 (3) ◽  
pp. 265
Author(s):  
N. V. Ramamurthy ◽  
B. K. Vinayagam ◽  
J. Roopchand
Keyword(s):  
Degrees Of Freedom ◽  
Ride Comfort ◽  
Controller Design ◽  
Research Work ◽  
Comfort Level ◽  
Lumped Parameter Model ◽  
Tracked Vehicle ◽  
Machine Model ◽  
Seat Suspension ◽  
Suspension Model

Military tracked vehicle and crew are modelled together in this paper as integrated man-machine lumped parameter model, by integrating the simplified 5 degrees of freedom (DoF) tracked vehicle model, including seat and 4 DoF human bio-dynamic model, thus resulting in a 9 DoF simplified vehicle-occupant model. Then the natural frequency of major mass segment namely the chassis mass is obtained through simulation study, for a known road input. The value obtained is compared with that of an earlier research work, for validation of said man-machine model. Then focusing our study locally at crew seat location, parameters of crew seat suspension for ride comfort are optimised using the optimal digital state space controller designed for this purpose by implementing it in a 2 DoF occupant - seat suspension model and its Simulink model constructed. Simulation results illustrate the attainment of the goal by meeting the controller design requirements.

Ergonomic Level Improving of Armoured Fighting Vehicle Crew

2017 ◽  
Vol 68 (1) ◽  
pp. 33
Author(s):  
N. V. Ramamurthy ◽  
B. K. Vinayagam ◽  
Roopchand J.
Keyword(s):  
Degrees Of Freedom ◽  
Ride Comfort ◽  
Equations Of Motion ◽  
Research Work ◽  
Composite Model ◽  
Seat Suspension ◽  
Lumped Parameter ◽  
Vibration Responses ◽  
Suspension Model ◽  
Parameter Values

<p class="p1">The armoured fighting vehicle (AFV)-occupant composite system is modelled as a lumped parameter system, in this paper, wherein the 4 degrees of freedom (dof) biodynamic occupant model is integrated with 10 dof in-plane AFV model including the crew seat, thus leading to the 14 dof vehicle-occupant composite model and the governing equations of motion are obtained. The composite model is subjected to idealised road input simulating the ground reaction forces. Natural frequencies and the frequency domain vibration responses of various masses of model are obtained. The natural frequency of chassis thus obtained is compared with the result established by an earlier research work, to validate the model. The study is focused on crew seat location. A 2 dof occupant-seat suspension model is formulated and validated through case study. The optimised values of seat suspension parameters for ride comfort are obtained using the said model, through two methods of Invariant points theory and genetic algorithm toolbox of Matlab 2014a software. Acceleration responses of body for the current and optimised parameter values obtained illustrate that comfort of crew is improved with optimised values through minimization in the acceleration responses.</p>

Vehicle Active Suspension with Four-Degrees of Freedom of Optimizing the Value of K Based on Genetic Algorithm

2011 ◽  
Vol 308-310 ◽  
pp. 1673-1678
Author(s):  
Yan Yan Zuo ◽  
Cai Bao Yan ◽  
Nan Yang
Keyword(s):  
Genetic Algorithm ◽  
Optimal Control ◽  
Optimal Control Theory ◽  
Degrees Of Freedom ◽  
Ride Comfort ◽  
Control Method ◽  
Active Suspension ◽  
Obvious Effect ◽  
Comprehensive Performance ◽  
Suspension Model

A vehicle active suspension model with 1 / 2 ，four-degrees of freedom is established and by combining genetic algorithm with optimal control theory，the author presents a new control method of active suspension that is to optimize the value of K controlled by LQG in default of road input based on genetic algorithm and makes a simulation in the environment of Matlab / Simulink. By simulation and analysis，the result indicates that，this method has an obvious effect on improving comprehensive performance of vehicles，such as ride comfort and operate stability and so on.

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.

A new coordinated control strategy for tracked vehicle ride comfort

2017 ◽  
Vol 232 (3) ◽  
pp. 330-341 ◽  
Author(s):  
Jianfeng Li ◽  
Amir Khajepour ◽  
Yanjun Huang ◽  
Hong Wang ◽  
Chen Tang ◽  
...  
Keyword(s):  
Control Strategy ◽  
Degrees Of Freedom ◽  
Target Location ◽  
Ride Comfort ◽  
Sliding Mode ◽  
Coordinated Control ◽  
Magnetorheological Damper ◽  
Vertical Acceleration ◽  
Tracked Vehicle ◽  
Multi Body

To improve tracked vehicle ride comfort and minimize weapon's vibration, a coordinated control strategy is developed for tracked vehicles' semi-active suspension systems. A model with eight degrees-of-freedom for a tracked vehicle equipped with magnetorheological dampers is established, and is followed by the formulation of a sliding mode controller. The proposed control algorithm is a localized-based controller that can change its target location in the tracked vehicle to where it is needed most. A co-simulation system model including a six-wheel tracked vehicle multi-body dynamics model, coordinated control strategy, and magnetorheological damper force allocator is developed to analyze the ride performance under bump and random road excitations. The simulation results demonstrate that the proposed strategy is very effective in improving the vehicle's ride performance and is much better than the traditional skyhook controllers. The innovation of this paper can be concluded as the coordinated control strategy can simultaneously improve vertical acceleration and pitch acceleration for the hull, which is of great importance for combat situations.

Mitigation of biodynamic response to vibratory and blast-induced shock loads using magnetorheological seat suspensions

2005 ◽  
Vol 219 (6) ◽  
pp. 741-753 ◽  
Author(s):  
Y-T Choi ◽  
N M Wereley
Keyword(s):  
Human Body ◽  
Lumped Parameter Model ◽  
Shock Load ◽  
Shock Loads ◽  
Seat Suspension ◽  
Military Vehicles ◽  
Lumped Parameter ◽  
Suspension Model ◽  
Yield Force ◽  
Constant Yield

The mitigation of biodynamic response to vibratory and blast-induced shock loads using a magnetorheological (MR) seat suspension is addressed in this study. To this end, an MR seat suspension model for military vehicles including seated personnel is constructed in terms of a detailed lumped parameter model. The lumped parameter model of the human body consists of four parts: pelvis, upper torso, viscera, and head. From the model, the governing equation of motion of the MR seat suspension considering the human body is derived. Based on this equation, a semi-active nonlinear optimal control algorithm appropriate for the MR seat suspension is developed. The simulated control performance of the MR seat suspension is evaluated under three different excitations of sinusoidal and random vibration and tremendous shock load due to a mine explosion. In addition, the mitigation of injuries to humans due to such a shock load is evaluated and compared with a passive hydraulic seat suspension and a passive MR seat suspension with a constant yield force.

Mitigation of Biodynamic Response to Vibratory and Blast-Induced Shock Loads Using Magnetorheological Seat Suspensions

Aerospace ◽  
2003 ◽  
Author(s):  
Young-Tai Choi ◽  
Norman M. Wereley
Keyword(s):  
Human Body ◽  
Control Algorithm ◽  
Random Vibration ◽  
Lumped Parameter Model ◽  
Shock Load ◽  
Hydraulic Damper ◽  
Seat Suspension ◽  
Military Vehicles ◽  
Lumped Parameter ◽  
Suspension Model

This study investigates biodynamic response mitigation to three different excitations of sinusoidal and random vibrations and shock load using a magnetorheological (MR) seat suspension. In doing so, an MR seat suspension model for military vehicles, with a detailed lumped parameter model of the human body, was developed. The lumped parameter model of the human body consists of four parts: pelvis, upper torso, viscera and head. From the model, the governing equation of motion of the MR seat suspension considering the human body was derived. Based on this equation, a semi-active nonlinear optimal control algorithm appropriate for the MR seat suspension was developed. The simulated control performance of the MR seat suspension was evaluated under three different excitations of sinusoidal and random vibration and tremendous shock load due to a mine explosion. In addition, the mitigation of injuries to humans due to such shock load was also evaluated and compared with the passive seat suspension using a passive hydraulic damper.

scholarly journals Nonlinear Dynamic Modelling of a Suspension Seat for Predicting the Vertical Seat Transmissibility

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Weitan Yin ◽  
Juyue Ding ◽  
Yi Qiu
Keyword(s):  
Nonlinear Dynamic ◽  
Ride Comfort ◽  
Dynamic Modelling ◽  
Vertical Vibration ◽  
Lumped Parameter Model ◽  
Nonlinear Behaviour ◽  
Seat Suspension ◽  
Lumped Parameter ◽  
Seat Cushion ◽  
Inert Mass

Suspension seats are widely used in heavy vehicles to reduce vibration transmitted to human body and promote ride comfort. Previous studies have shown that the dynamics of the suspension seat exhibits nonlinear behaviour with changed vibration magnitudes. Despite various linear seat models developed in the past, a nonlinear model of the suspension seat capturing the nonlinear dynamic behaviour of the seat suspension and cushion has not been developed for the prediction of the seat transmissibility. This paper proposes a nonlinear lumped parameter model of the suspension seat to predict the nonlinear dynamic response of the seat. The suspension seat model comprises of a nonlinear suspension submodel integrated with a nonlinear cushion submodel. The parameters of the submodels are determined by minimizing the error between the simulated and the measured transmissibility of the suspension mechanism and the force-deflection curve of the seat cushion, respectively. The model of the complete seat is then validated using the seat transmissibility measured with inert mass under vertical vibration excitation. The results show that the proposed suspension seat model can be used to predict the seat transmissibility with various excitation magnitudes.

Optimization of dynamically sensitive parameters of Linke Hofmann Busch coach considering suspended equipment using design of experiment

2019 ◽  
Vol 25 (12) ◽  
pp. 1793-1811 ◽  
Author(s):  
S.D. Singh ◽  
Rakesh Mathur ◽  
R.K. Srivastava
Keyword(s):  
Sensitivity Analysis ◽  
Design Of Experiment ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Research Work ◽  
Comfort Level ◽  
Design Parameters ◽  
Response Analysis ◽  
Frequency Range ◽  
Response Level

The high speed coach running on irregular track is always accompanied by inferior comfort for the passengers. The optimal design of coach parameters improving comfort level can be achieved through response analysis. The present study is concerned with the optimization of Linke Hofmann Busch rail coach design parameters to augment comfort level. The coach body and bogie frame under four degrees of freedom are modeled with the finite element method to obtain dynamic parameters of the coach, that is, eigenvalues and eigenvectors. The sensitivity analysis based on partial derivatives against frequency response function displacement with respect to various design parameters is conducted, and most influential coach parameters are optimized through computer experimentation using central composite design and response surface methodology of design of experiment (DOE). Using modal parameters obtained as above and Indian Rail Road power spectral density of track irregularities, both vertical and lateral responses are determined at vicinity to the center mass of coach body in a 0.1– 40 Hz frequency range of interest. Results conclude that peak vertical responses occur in 0 – 10 Hz, whereas peak lateral responses fall at still lower frequency representing long wavelength irregularities of track that causes discomfort to vehicle riders. Findings of the research work embodied herein reveal that the left end bio toilet tank mass has least effect on response. Also, these findings suggest scope for further attainment in comfort level by computer experimentation for combinations of three coach design parameters (wheel base, equivalent primary, and secondary suspension stiffness) on minimizing the response level without altering the basic design of the coach model. The present paper represents a significant move forward on the dynamic analysis of coach body considering suspended equipment, sensitivity analysis through mathematical approach rather than step parametric variation, and its optimization through DOE, which have not been addressed earlier. The outcome of the paper may help rail coach designers to modify coach design parameters for better comfort level, even in the low frequency range of operation.

scholarly journals Design of Constrained Robust Controller for Active Suspension of In-Wheel-Drive Electric Vehicles

Mathematics ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 249
Author(s):  
Xianjian Jin ◽  
Jiadong Wang ◽  
Shaoze Sun ◽  
Shaohua Li ◽  
Junpeng Yang ◽  
...  
Keyword(s):  
Electric Vehicles ◽  
Ride Comfort ◽  
Controller Design ◽  
Active Suspension ◽  
Suspension System ◽  
Parameter Uncertainties ◽  
Dynamic Vibration Absorber ◽  
Robust Controller ◽  
Wheel Drive ◽  
Suspension Model

This paper presents a constrained robust H∞ controller design of active suspension system for in-wheel-independent-drive electric vehicles considering control constraint and parameter variation. In the active suspension system model, parameter uncertainties of sprung mass are analyzed via linear fraction transformation, and the perturbation bounds can be also limited, then the uncertain quarter-vehicle active suspension model where the in-wheel motor is suspended as a dynamic vibration absorber is built. The constrained robust H∞ feedback controller of the closed-loop active suspension system is designed using the concept of reachable sets and ellipsoids, in which the dynamic tire displacements and the suspension working spaces are constrained, and a comprehensive solution is finally derived from H∞ performance and robust stability. Simulations on frequency responses and road excitations are implemented to verify and evaluate the performance of the designed controller; results show that the active suspension with a developed H∞ controller can effectively achieve better ride comfort and road-holding ability compared with passive suspension despite the existence of control constraints and parameter variations.

Singular System-Based Approach for Active Vibration Control of Vehicle Seat Suspension

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Wenxing Li ◽  
Haiping Du ◽  
Zhiguang Feng ◽  
Donghong Ning ◽  
Weihua Li ◽  
...  
Keyword(s):  
Vibration Control ◽  
Ride Comfort ◽  
Actuator Saturation ◽  
Singular System ◽  
Active Vibration Control ◽  
Seat Suspension ◽  
Active Vibration ◽  
System States ◽  
Suspension Model ◽  
Vehicle Seat

Abstract This paper proposes a singular system-based approach for active vibration control of vehicle seat suspensions, where the drivers' acceleration is augmented into the conventional seat suspension model together with seat suspension deflection and relative velocity as system states to make the suspension model as a singular system. In this novel seat suspension system, all the system states are easy to measure in real-time. A friction observer is applied to estimate the real system friction and an H∞ controller is designed to achieve the optimal ride comfort performance with consideration of the friction compensation, actuator saturation, and time delay issues. The cone complementarity linearization (CCL) algorithm is applied to solve the nonlinear constraints. The experimental results show that good ride comfort performance can be achieved by the proposed controller in both the time and frequency domain compared with the uncontrolled seat suspension.

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