scholarly journals An Improved Genetic Algorithm to Optimize Spatial Locations for Double-Wishbone Type Suspension System with Time Delay

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Qiang Li ◽  
Xiaoli Yu ◽  
Jian Wu
Keyword(s):  
Time Delay ◽  
Ride Comfort ◽  
Optimization Method ◽  
Front Wheel ◽  
Vehicle Speed ◽  
Improved Genetic Algorithm ◽  
Vehicle Performance ◽  
Front Suspension ◽  
Wheel Alignment ◽  
Spatial Locations

By taking account of double-wishbone independent suspension with two unequal-length arms, the coordinate values of articulated geometry are based on structural limitations and constraint equations of alignment parameters. The sensitivities of front wheel alignment parameters are analyzed using the space analytic geometry method with insight module in ADAMS® software. The multiobjective optimization functions are designed to calculate the coordinate values of hardpoints with front suspension since the effect of time delay due to wheelbase can be easily obtained by vehicle speed. The K&C characteristics have been investigated using GA solutions in the simulation environment. The camber angle decreases from 1.152° to 1.05° and toe-in angle reduces from 1.036° to 0.944°. The simulation results demonstrate that the suggested optimization method is able to satisfy the suspension motion to enhance ride comfort. Experimental results, obtained by K&C test bench, also indicate that the optimized suspension can track the desired trajectory while keeping the vehicle performance in various road conditions.

Study and Simulation on Truck Front Suspension Using ADAMS

2013 ◽  
Vol 433-435 ◽  
pp. 2235-2238
Author(s):  
Wei Ning Bao
Keyword(s):  
System Dynamics ◽  
Mechanical System ◽  
Steering System ◽  
Front Wheel ◽  
System Model ◽  
Simulation Test ◽  
Front Suspension ◽  
Body Dynamics ◽  
Wheel Alignment ◽  
Multi Body

The mechanical system dynamics software,ADAMS,is used to establish multi-body dynamics system model for a truck front suspension and steering system. Through the simulation test of wheel travel, front wheel alignment parameters changing along with the wheel travel was obtained.

Parameters uncertainty in pareto optimization of nonlinear inerter-based suspension system under nonstationary random road excitation

2021 ◽  
pp. 095440702110609
Author(s):  
Abolfazl Seifi ◽  
Reza Hassannejad
Keyword(s):  
Ride Comfort ◽  
Suspension System ◽  
Vehicle Speed ◽  
Main Function ◽  
Vehicle Performance ◽  
Suspension Systems ◽  
Proposed Model ◽  
Tire Stiffness ◽  
Road Excitation ◽  
New Type

Ignoring the possible impacts of uncertainties in vehicle components during the design phase can undermine the safety of passengers and the vehicle performance. The main function of a suspension system is to provide satisfactory ride comfort and road-holding with a sufficiently low probability of rollover. Despite many studies on the design of new suspension systems with inerters, the effect of uncertainties in vehicle weight and tire stiffness on the design of suspension with inerters has not received much attentions. This paper presents a new type of suspension with inerters and asymmetric dampers and investigates the dynamic behavior of a vehicle under variable vehicle speed. Moreover, the effect of uncertainties on the choice of acceptable values of inerters is evaluated. For this investigation, the authors developed a 9-DOF full vehicle model with roll and yaw motions under non-stationary random road excitations in the time and frequency domains and studied its dynamic response with different suspension models. The optimal design was performed using a multi-objective optimization algorithm called MOEA/D. The best model was then used to determine the effect of uncertainties on the choice of inerters. The optimization results show that using the optimized suspension with inerters and nonlinear dampers instead of conventional design improves the ride comfort by 0.16%, the vehicle road-holding by 3.54%, and the rollover probability by 44.73%. In the proposed model, by changing the values of vehicle parameters with uncertainty, the choice of inerters to have an acceptable performance would be variable.

scholarly journals Research on Model Predictive Control for Automobile Active Tilt Based on Active Suspension

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 671
Author(s):  
Jialing Yao ◽  
Meng Wang ◽  
Zhihong Li ◽  
Yunyi Jia
Keyword(s):  
Load Transfer ◽  
Ride Comfort ◽  
Active Suspension ◽  
Path Tracking ◽  
Roll Angle ◽  
Lateral Acceleration ◽  
Vehicle Speed ◽  
Model Predictive Controller ◽  
Advantages And Disadvantages ◽  
Predictive Controller

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.

Comprehensive Analysis for Influence of Controllable Damper Time Delay on Semi-Active Suspension Control Strategies

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Yechen Qin ◽  
Feng Zhao ◽  
Zhenfeng Wang ◽  
Liang Gu ◽  
Mingming Dong
Keyword(s):  
Time Delay ◽  
Dynamic Characteristics ◽  
Ride Comfort ◽  
Hybrid Control ◽  
Sliding Mode ◽  
Control Strategies ◽  
Active Suspension ◽  
Test System ◽  
Suspension Control ◽  
Simulation Results

This paper presents a comprehensive comparison and analysis for the effect of time delay on the five most representative semi-active suspension control strategies, and refers to four unsolved problems related to semi-active suspension performance and delay mechanism that existed. Dynamic characteristics of a commercially available continuous damping control (CDC) damper were first studied, and a material test system (MTS) load frame was used to depict the velocity-force map for a CDC damper. Both inverse and boundary models were developed to determine dynamic characteristics of the damper. In addition, in order for an improper damper delay of the form t+τ to be corrected, a delay mechanism of controllable damper was discussed in detail. Numerical simulation for five control strategies, i.e., modified skyhook control SC, hybrid control (HC), COC, model reference sliding mode control (MRSMC), and integrated error neuro control (IENC), with three different time delays: 5 ms, 10 ms, and 15 ms was performed. Simulation results displayed that by changing control weights/variables, performance of all five control strategies varied from being ride comfort oriented to being road handling oriented. Furthermore, increase in delay time resulted in deterioration of both ride comfort and road handling. Specifically, ride comfort was affected more than road handling. The answers to all four questions were finally provided according to simulation results.

Effect of unsupported sleepers on dynamic behavior of running vehicles and ride comfort index

2021 ◽  
pp. 095440622198937
Author(s):  
Mojtaba Azizi ◽  
Majid Shahravi ◽  
Jabbar-Ali Zakeri
Keyword(s):  
Numerical Model ◽  
Dynamic Behavior ◽  
Multibody Dynamics ◽  
Field Test ◽  
Ride Comfort ◽  
Vehicle Speed ◽  
Comfort Index ◽  
Railway Industry ◽  
Flexible Track ◽  
Train Speed

Nowadays, with various advancements in the railway industry and increasing speed of trains, the design of railway tracks and vehicles has become vitally important. One of the frequent problems of ballasted tracks is the existence of unsupported sleepers. This phenomenon occurs due to the lack of ballast underneath the sleepers. Here, a model is presented, in which a flexible track model in a multibody dynamics program is developed, in order to study the dynamic behavior of a vehicle. By utilizing the model, it is feasible to simulate unsupported sleepers on the flexible track including rail, sleeper, and ballast components. In order to verify the results of numerical model, a field test is performed. Findings indicate that, in the case of a single unsupported sleeper through the track, the ride comfort index increased by 100% after increasing the train speed from 30 to 110 km/h. Moreover, when it is needed to have ride comfort index improvement over the uncomfortable level, the vehicle speed should be less than 70 km/h and 50 km/h for tracks with one unsupported sleeper and two unsupported sleepers, respectively.

scholarly journals Global Optimization Method to Multiple Local Optimals with the Surface Approximation Methodology and Its Application for Industry Problems

2021 ◽  
Author(s):  
Ichiro Hagiwara
Keyword(s):  
Neural Network ◽  
Region Of Interest ◽  
Optimization Method ◽  
Mapping Method ◽  
Vehicle Performance ◽  
Vehicle Component ◽  
Generalized Inverse Matrix ◽  
Global Optimal ◽  
Function Approximations ◽  
Vehicle Crashworthiness

Although generally speaking, a great number of functional evaluations may be required until convergence, it can be solved by using neural network effectively. Here, techniques to search the region of interest containing the global optimal design selected by random seeds is investigated. Also techniques for finding more accurate approximation using Holographic Neural Network (HNN) improved by using penalty function for generalized inverse matrix is investigated. Furthermore, the mapping method of extrapolation is proposed to make the technique available to general application in structural optimization. Application examples show that HNN may be expected as potential activate and feasible surface functions in response surface methodology than the polynomials in function approximations. Finally, the real design examples of a vehicle performance such as idling vibration, booming noise, vehicle component crash worthiness and combination problem between vehicle crashworthiness and restraint device performance at the head-on collision are used to show the effectiveness of the proposed method.

scholarly journals Linear time-delay circuit and stabilizing controller

2021 ◽  
Vol 2091 (1) ◽  
pp. 012005
Author(s):  
Yuhao Cong ◽  
Yong Zhang ◽  
Guang-Da Hu
Keyword(s):  
Time Delay ◽  
Large Time ◽  
Linear Time ◽  
Least Square Method ◽  
Optimization Method ◽  
Delay System ◽  
Least Square ◽  
Single Chip ◽  
Stabilizing Controller ◽  
Delay Circuit

Abstract This paper is concerned with a linear time-delay circuit and its feedback control. We use electronic components such as resistors and capacitors to realize a linear time-delay system. The time-delays are generated by operational amplifiers and single-chip microcomputers. Based on the actual data measured by the oscilloscope, the parameters of the system are estimated using the least square method. Then a comparison study between the waveform image measured by the oscilloscope and the numerical simulation obtained by MATLAB verifies the effectiveness of the parameters estimations of the circuit system. Furthermore, the circuit system is unstable with a large time-delay, a feedback controller is designed to stabilize the circuit system using the optimization method in the literature. Finally, the experimental results in the linear time-delay circuit show the effectiveness of the optimization method.

scholarly journals Robust optimal control of a nonlinear impulsive time-delay system for 1,3-PD fed-batch culture

2021 ◽  
Vol 2113 (1) ◽  
pp. 012022
Author(s):  
Chao Sun
Keyword(s):  
Optimal Control ◽  
Time Delay ◽  
Control Variable ◽  
Optimization Method ◽  
Delay System ◽  
Experimental Result ◽  
Time Delay System ◽  
Robust Optimal Control ◽  
Robust Model ◽  
Feeding Process

Abstract In this paper, taking the feeding process as a form of impulsive and considering the time-delay in fermentation process. A robust model with the time-delay system as the control variable and the time-delay system as the constraint is established. In order to solve this optimal control problem, we have propose an particle swarm optimization method to solve problem. Numerical results show that 1,3-PD yield at the terminal time increases compared with the experimental result.

Research on Human and Vehicles Coordination Evacuation Simulation Optimization Method under Emergency Incidents

2011 ◽  
Vol 71-78 ◽  
pp. 3091-3096
Author(s):  
Yun Long Ma ◽  
Jian Wang
Keyword(s):  
Ant Colony Algorithm ◽  
Simulation Optimization ◽  
Optimization Method ◽  
Emergency Planning ◽  
Optimal Scheduling ◽  
Regular Pattern ◽  
Improved Genetic Algorithm ◽  
Evacuation Simulation ◽  
Evacuation Strategy ◽  
Coordination System

Among researches on crowd flow evacuation under emergency, there are no deep touch of coordinating evacuation strategy of crowd and traffic, and also can not set models and simulate the whole picture of evacuation. The purpose of this research is to realize the coordinating evacuation of both traffic and crowd. The author divided the situations into Not Intervene and May Intervene, analyzed the coordination system and probed the model of coordinating evacuation. A series of coordinate evacuation method has been put forward based on swarm intelligence and simulation optimization. Based on the result of crowd simulation and Ant colony algorithm, in order to find the optimal traffic evacuation proposal, the author took use of the improved Genetic Algorithm as well as the distributed coordinating simulation, finally found a systematic optimal scheduling program. Also the internal regular pattern of coordinating evacuation has also been revealed. All these will provide support for emergency planning and decision making.

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