Energy-Harvesting Shock Absorbers With Ride Comfort Controller on Vehicle

2016 ◽  
Author(s):  
Chien-An Chen ◽  
Khai D. T. Ngo ◽  
Lei Zuo
Keyword(s):  
Ride Comfort ◽  
Controller Design ◽  
Circuit Simulation ◽  
Fuel Efficiency ◽  
Nonlinear Behavior ◽  
Power Converter ◽  
Input Current ◽  
Vehicle Body ◽  
Shock Absorbers ◽  
Force Tracking

In order to achieve higher fuel efficiency and better ride comfort, this paper introduces a shock absorber system including Mechanical-Motion-Rectifier (MMR), power converter and its current/force tracking (ICFT) controller. MMR based shock absorbers has the benefit of higher efficiency and better mechanical reliability than conventional regenerative shock absorbers. However, the one-way clutches and inertia in MMR induce disengagement between input shaft and generator. This nonlinear behavior makes the input current/force of MMR uncontrollable with conventional feedback controller design. To solve this problem, this paper presents an input current/force tracking (ICFT) controller for MMR based suspension system. By adding additional control laws to the conventional controller, ICFT controller successfully solves the nonlinearity problem during MMR control. This ICFT controller is tested by tracking the reference force from skyhook control to improve ride comfort. The vehicle body displacement is simulated under specified speedbump. By using this ICFT controller, the simulation result show displacement error between skyhook and ICFT-MMR is within 5% and its total harvested energy is 56 joules, as 56 W of average input power. Equivalent circuits used for circuit simulation are proved to have identical performances as mechanical models.

Application of Semi-Active Inerter in Semi-Active Suspensions Via Force Tracking

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Michael Z. Q. Chen ◽  
Yinlong Hu ◽  
Chanying Li ◽  
Guanrong Chen
Keyword(s):  
Active Control ◽  
Ride Comfort ◽  
Controller Design ◽  
Active Suspension ◽  
Damping Coefficient ◽  
Control Law ◽  
Control Force ◽  
Car Model ◽  
Force Tracking ◽  
Active Damper

This paper investigates the application of semi-active inerter in semi-active suspension. A semi-active inerter is defined as an inerter whose inertance can be adjusted within a finite bandwidth by online control actions. A force-tracking approach to designing semi-active suspension with a semi-active inerter and a semi-active damper is proposed in this paper. Two parts are required in the force-tracking strategy: a target active control law and a proper algorithm to adjust the inertance and the damping coefficient online to track the target active control law. The target active control law is derived based on the state-derivative feedback control methodology in the “reciprocal state-space” (RSS) framework, which has the advantage that it is straightforward to use the acceleration information in the controller design. The algorithm to adjust the inertance and the damping coefficient is to saturate the active control force between the maximal and the minimal achievable suspension forces of the semi-active suspension. Both a quarter-car model and a full-car model are considered in this paper. Simulation results demonstrate that the semi-active suspension with a semi-active inerter and a semi-active damper can track the target active control force much better than the conventional semi-active suspension (which only contains a semi-active damper) does. As a consequence, the overall performance in ride comfort, suspension deflection, and road holding is improved, which effectively demonstrates the necessity and the benefit of introducing semi-active inerter in vehicle suspension.

scholarly journals Hardware in the Loop Testing of Adaptive Inertia Weight PSO-Tuned LQR Applied to Vehicle Suspension Control

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Joshua Sunder David Reddipogu ◽  
Vinodh Kumar Elumalai
Keyword(s):  
Optimization Problem ◽  
Ride Comfort ◽  
Controller Design ◽  
Linear Quadratic Regulator ◽  
Vehicle Body ◽  
Linear Quadratic ◽  
Body Acceleration ◽  
Inertia Weight ◽  
Optimal Weights ◽  
Road Profile

This paper presents an adaptive inertia weight particle swarm optimization (AIWPSO) employed for solving the multiobjective weight optimization problem of LQR applied for the vehicle active suspension system (ASS). To meet the competing control objectives of ASS including the ride comfort, road handling, and suspension travel, the state feedback controller design for ASS is formulated as an optimization problem and an improved PSO is employed for finding the optimal weights of the linear-quadratic regulator (LQR). Specifically, for solving the premature convergence of the particles and imbalance between exploration and exploitation capabilities of PSO, an adaptive inertia weight that updates the velocity of the particles based on the success rate is used. The efficacy of the AIWPSO-tuned LQR is experimentally tested on a quarter-car ASS plant using the hardware in loop (HIL) testing for an uneven road surface. Experimental results highlight that, compared to conventional PSO-tuned LQR, the proposed scheme can significantly minimize the vehicle body acceleration due to irregular road profile while guaranteeing the minimum tire friction for passenger safety. The ISO 2361-1 standards adopted to evaluate the ride and health criteria substantiate that the proposed scheme reduces the vibration dose value by 25.34% for a bumpy road profile. Moreover, the cumulative power spectral density (CPSD) of vehicle body acceleration assessed in both low- and high-frequency regions manifests the significant improvement in the ride comfort.

scholarly journals Design of Center Pillar with Composite Reinforcements Using Hybrid Molding Method

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2047
Author(s):  
Ji-Heon Kang ◽  
Jae-Wook Lee ◽  
Jae-Hong Kim ◽  
Tae-Min Ahn ◽  
Dae-Cheol Ko
Keyword(s):  
Composite Materials ◽  
Weight Reduction ◽  
Fuel Efficiency ◽  
Vehicle Body ◽  
Process Time ◽  
Fiber Reinforced ◽  
Fiber Reinforced Plastic ◽  
Molding Method ◽  
Reinforced Plastic ◽  
Composite Reinforcements

Recently, with the increase in awareness about a clean environment worldwide, fuel efficiency standards are being strengthened in accordance with exhaust gas regulations. In the automotive industry, various studies are ongoing on vehicle body weight reduction to improve fuel efficiency. This study aims to reduce vehicle weight by replacing the existing steel reinforcements in an automobile center pillar with a composite reinforcement. Composite materials are suitable for weight reduction because of their higher specific strength and stiffness compared to existing steel materials; however, one of the disadvantages is their high material cost. Therefore, a hybrid molding method that simultaneously performs compression and injection was proposed to reduce both process time and production cost. To replace existing steel reinforcements with composite materials, various reinforcement shapes were designed using a carbon fiber-reinforced plastic patch and glass fiber-reinforced plastic ribs. Structural analyses confirmed that, using these composite reinforcements, the same or a higher specific stiffness was achieved compared to the that of an existing center pillar using steel reinforcements. The composite reinforcements resulted in a 67.37% weight reduction compared to the steel reinforcements. In addition, a hybrid mold was designed and manufactured to implement the hybrid process.

scholarly journals Study on Friction in Automotive Shock Absorbers Part 1: Friction Simulation Using a Dynamic Friction Model in the Contact Zone of an FEM Model

Vehicles ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 212-232
Author(s):  
Ludwig Herzog ◽  
Klaus Augsburg
Keyword(s):  
Ride Comfort ◽  
Viscous Friction ◽  
Simulation Method ◽  
Friction Model ◽  
Model Parameters ◽  
Dynamic Friction ◽  
Friction Modeling ◽  
Shock Absorbers ◽  
Operation Conditions ◽  
Wide Range

The important change in the transition from partial to high automation is that a vehicle can drive autonomously, without active human involvement. This fact increases the current requirements regarding ride comfort and dictates new challenges for automotive shock absorbers. There exist two common types of automotive shock absorber with two friction types: The intended viscous friction dissipates the chassis vibrations, while the unwanted solid body friction is generated by the rubbing of the damper’s seals and guides during actuation. The latter so-called static friction impairs ride comfort and demands appropriate friction modeling for the control of adaptive or active suspension systems. In this article, a simulation approach is introduced to model damper friction based on the most friction-relevant parameters. Since damper friction is highly dependent on geometry, which can vary widely, three-dimensional (3D) structural FEM is used to determine the deformations of the damper parts resulting from mounting and varying operation conditions. In the respective contact zones, a dynamic friction model is applied and parameterized based on the single friction point measurements. Subsequent to the parameterization of the overall friction model with geometry data, operation conditions, material properties and friction model parameters, single friction point simulations are performed, analyzed and validated against single friction point measurements. It is shown that this simulation method allows for friction prediction with high accuracy. Consequently, its application enables a wide range of parameters relevant to damper friction to be investigated with significantly increased development efficiency.

scholarly journals Mathematical Modelling of Two-Wheeler Suspension system in a wavy road

2019 ◽  
Vol 8 (11) ◽  
pp. 3630-3635
Keyword(s):  
Ride Comfort ◽  
Health Hazard ◽  
Suspension System ◽  
Vehicle Body ◽  
Continuous Exposure ◽  
Potential Health ◽  
Suspension Spring ◽  
The Road ◽  
Potential Health Hazard ◽  
Two Wheeler

Two wheelers like motorbikes and scooters are one of the major transports in India. In major cities and towns, it is most common private transport as it is fast and easy approach to the destination. But the prolonged drive in the two-wheeler leads to the potential health hazard and musco-skeletal disorder due to continuous exposure to the vibration caused during the ride and force transmitted to the vehicle body due to road irregularities. It is a challenge of automobile engineers to design a promising suspension system to overcome the risk of ride comfort during continuous driving. In this research, two-wheeler suspension system is modelled with a condition of bump and valley in a wavy road. The road surface is assumed to be wavy and the response of new suspension spring with different materials (stainless steel, tungsten and polymeric) along with viscous damper is analyzed and compared. By this analysis, it will be proposed to industry to modify the suspension system to improve its efficiency and reduce force transmitted to the human body to improve the ride comfort

Comparative Study of Magnetorheological Damper Models for Force Tracking

2015 ◽  
Author(s):  
Anria Strydom ◽  
Werner Scholtz ◽  
Schalk Els
Keyword(s):  
Computational Efficiency ◽  
Ride Comfort ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Damping Force ◽  
Suspension Systems ◽  
Mr Dampers ◽  
Damping Characteristics ◽  
Force Tracking ◽  
Control Application

Magnetorheological (MR) dampers are controllable semi-active dampers capable of providing a range of continuous damping settings. MR dampers are often incorporated in suspension systems of vehicles where conflicting damping characteristics are required for favorable ride comfort and handling behavior. For control applications the damper controller determines the required damper current in order to track the desired damping force, often by using a suitable MR damper model. In order to utilise the fast switching time capability of MR dampers, a model that can be used to directly calculate damper current is desired. Unfortunately few such models exist and other methods, which often negatively affect the computational efficiency of the model, need to be used when implementing these models. In this paper a selection of MR damper models are developed and evaluated for both accuracy and computational efficiency while tracking a desired damping force. The Kwok model is identified as a suitable candidate for the intended suspension control application.

scholarly journals Design and Analysis of a Repetitive Current Controller for a Single-Phase Bridgeless SEPIC PFC Converter

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 131 ◽  
Author(s):  
Jinwoo Kim ◽  
Sanghun Han ◽  
Wontae Cho ◽  
Younghoon Cho ◽  
Hyunsoo Koh
Keyword(s):  
Controller Design ◽  
Harmonic Distortion ◽  
Input Current ◽  
Order Model ◽  
Third Order ◽  
Current Controller ◽  
The Stability ◽  
Small Signal Modeling ◽  
Fifth Order ◽  
Repetitive Controller

This paper studies a repetitive controller design scheme for a bridgeless single-ended primary inductor converter (SEPIC) power factor correction (PFC) converter to mitigate input current distortions. A small signal modeling of the converter is performed by a fifth-order model. Since the fifth-order model is complex to be applied in designing a current controller, the model is approximated to a third-order model. Using the third-order model, the repetitive controller is designed to reduce the input current distortion. Then, the stability of the repetitive controller is verified with an error transfer function. The proposed controller performance is validated by simulation, and the experiment results show that the input current total harmonic distortion (THD) is improved by applying the proposed controller for an 800 W bridgeless SEPIC PFC converter prototype.

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