No-Jerk Skyhook Control Methods for Semiactive Suspensions

2004 ◽  
Vol 126 (4) ◽  
pp. 580-584 ◽  
Author(s):  
Mehdi Ahmadian ◽  
Xubin Song ◽  
Steve C. Southward
Keyword(s):  
Relative Velocity ◽  
Magnetorheological Damper ◽  
Damping Force ◽  
Electrical Currents ◽  
Zero Crossings ◽  
Seat Suspension ◽  
Suspension Systems ◽  
Heavy Truck ◽  
The Relationship ◽  
Study Offer

This paper presents two alternative implementations of skyhook control, named “skyhook function” and “no-jerk skyhook,” for reducing the dynamic jerk that is often experienced with conventional skyhook control in semiactive suspension systems. An analysis of the relationship between the absolute velocity of the sprung mass and the relative velocity across the suspension are used to show the damping-force discontinuities that result from the conventional implementation of skyhook control. This analysis shows that at zero crossings of the relative velocity, conventional skyhook introduces a sharp increase (jump) in damping force, which, in turn, causes a jump in sprung-mass acceleration. This acceleration jump, or jerk, causes a significant reduction in isolation benefits that can be offered by skyhook suspensions. The alternative implementations of skyhook control included in this study offer modifications to the formulation of conventional skyhook control such that the damping force jumps are eliminated. The alternative policies are compared to the conventional skyhook control in the laboratory, using a base-excited semiactive system that includes a heavy-truck seat suspension. An evaluation of the damping force, seat acceleration, and the electrical currents supplied to a magnetorheological damper, which is used for this study, shows that the alternative implementations of skyhook control can entirely eliminate the damping-force discontinuities and the resulting dynamic jerks caused by conventional skyhook control.

Eliminating the Unwanted Dynamics From the Controllable Suspensions for Vehicle Applications

2002 ◽  
Author(s):  
Xubin Song ◽  
Mehdi Ahmadian ◽  
Steve C. Southward
Keyword(s):  
Relative Velocity ◽  
Damping Force ◽  
Electrical Currents ◽  
Zero Crossings ◽  
Seat Suspension ◽  
Suspension Systems ◽  
Excited System ◽  
Heavy Truck ◽  
Magneto Rheological ◽  
Semiactive Suspension

This paper presents two alternative implementations of skyhook control, named “skyhook function” and “no-jerk skyhook,” for reducing the dynamic jerk that is often experienced with conventional skyhook control in semiactive suspension systems. An analysis of the relationship between the absolute velocity of the sprung mass and the relative velocity across the suspension are used to show the damping force discontinuities that result from the conventional implementation of skyhook control. This analysis shows that at zero crossings of the relative velocity, conventional skyhook introduces a sharp increase (jump) in damping force, which, in turn, causes a jump in sprung mass acceleration. This acceleration jump, or jerk, causes a significant reduction in isolation benefits that can be offered by skyhook suspensions. The alternative implementations of skyhook control included in this study offer modifications to the formulation of conventional skyhook control such that the damping force jumps are eliminated. The alternative policies are compared with the conventional skyhook control, using a laboratory implementation on a heavy truck seat suspension that represents a base-excited system with a semiactive suspension. An evaluation of the damping force, seat acceleration, and the electrical currents supplied to a magneto-rheological (MR) damper that is used for this study, shows that the alternative implementations of skyhook control can entirely eliminate the damping force discontinuities and the resulting dynamic jerks caused by conventional skyhook control.

scholarly journals Design of a Novel Magnetorheological Damper Adaptable to Low and High Stroke Velocity of Vehicle Suspension System

2020 ◽  
Vol 10 (16) ◽  
pp. 5586
Author(s):  
Bo-Gyu Kim ◽  
Dal-Seong Yoon ◽  
Gi-Woo Kim ◽  
Seung-Bok Choi ◽  
Aditya Suryadi Tan ◽  
...  
Keyword(s):  
Shape Function ◽  
Mr Damper ◽  
Effective Area ◽  
Magnetorheological Damper ◽  
Damping Coefficient ◽  
Vehicle Suspension ◽  
Damping Force ◽  
Piston Velocity ◽  
Suspension Systems ◽  
Vehicle Suspension System

In this study, a new class of magnetorheological (MR) damper, which can realize desired damping force at both low and high speeds of vehicle suspension systems, is proposed and its salient characteristics are shown through computer simulations. Unlike conventional MR dampers, the proposed MR damper has a specific pole shape function and therefore the damping coefficient is changed by varying the effective area of the main orifice. In addition, by controlling the opening or closing the bypass orifice, the drastic change of the damping coefficient is realizable. After briefly describing the operating principle, a mathematical modeling is performed considering the pole shape function which is a key feature of the proposed MR damper. Then, the field-dependent damping force and piston velocity-dependent characteristics are presented followed by an example on how to achieve desired damping force characteristics by changing the damping coefficient and slope breaking point which represents the bilinear damping property.

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.

Vibration Control of a Seat Suspension System Using Magnetorheological Damper

2009 ◽  
Author(s):  
H. Metered ◽  
P. Bonello ◽  
S. O. Oyadiji
Keyword(s):  
Control System ◽  
Active Control ◽  
Ride Comfort ◽  
Mr Damper ◽  
Suspension System ◽  
Magnetorheological Damper ◽  
Performance Criteria ◽  
Effective Control ◽  
Damping Force ◽  
Seat Suspension

Seat suspension system is critical to the ride comfort experience of a vehicle’s driver and passengers. The use of a magnetorheological (MR) damper in a seat suspension system has been shown to offer significant benefits in this regard. Most research on seat MR dampers has applied active control strategies to command the MR damper, which is an inherently semi-active device. This paper introduces a more suitable semi-active control strategy for an MR damper used in a seat suspension, enabling more effective control. The proposed control system comprises a system controller that computes the desired damping force using a sliding mode control algorithm, and a neural-based damper controller that provides a direct estimation of the command voltage that is required to track the desired damping force. The seat suspension system is approximated by base-excited single degree of freedom system. The proposed semi-active seat suspension is compared to a passive seat suspension for prescribed base displacements. These inputs are representative of the vibration of the sprung mass of a passive or semi-active quarter-vehicle suspension under bump or random-profile road disturbance. Control performance criteria such as seat travel distance and seat acceleration are evaluated in time and frequency domains, in order to quantify the effectiveness of proposed semi-active control system. The simulated results reveal that the use of semi-active control in the seat suspension provides a significant improvement in ride comfort.

A novel scissor-type magnetorheological seat suspension system with self-sustainability

2018 ◽  
Vol 30 (5) ◽  
pp. 665-676 ◽  
Author(s):  
Jianqiang Yu ◽  
Xiaomin Dong ◽  
Zonglun Zhang ◽  
Pinggen Chen
Keyword(s):  
Control Algorithm ◽  
Balance Control ◽  
Experimental Tests ◽  
The Self ◽  
Magnetorheological Damper ◽  
Damping Force ◽  
Seat Suspension ◽  
Electrical Part ◽  
Self Powered ◽  
And Control

A novel scissor-type magnetorheological seat suspension with self-sustainability which integrated self-powered, self-sensing, and self-adaptability is proposed in this study. The adaptive rotary damping system consisted of the rotary magnetorheological damper, and rotary permanent magnet direct current generator is designed to realize the self-sustainability. Effects of damping force and isolation object mass are analyzed for further designing and testing based on the dynamic model. The rotary magnetorheological damper and the electrical part are designed and analyzed theoretically. Series of experimental tests are conducted to verify the feasibility and control performances. The experimental results show that the on–off balance control algorithm based on the self-sensing signals can improve the comfort than the directly and supply-with-rectifier control modes.

scholarly journals Integrated active and semi-active control for seat suspension of a heavy duty vehicle

2017 ◽  
Vol 29 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Donghong Ning ◽  
Shuaishuai Sun ◽  
Haiping Du ◽  
Weihua Li
Keyword(s):  
Resonance Frequency ◽  
Active Control ◽  
Integrated Control ◽  
Relative Displacement ◽  
Magnetorheological Damper ◽  
Active Force ◽  
Heavy Duty ◽  
Force Output ◽  
Seat Suspension ◽  
A Current

In this article, an integrated active and semi-active seat suspension for heavy duty vehicles is proposed, and its prototype is built; an integrated control algorithm applied measurable variables (suspension relative displacement and seat acceleration) is designed for the proposed seat prototype. In this seat prototype, an active actuator with low maximum force output (70 N), which is insufficient for an active seat suspension to control the resonance vibration, is applied together with a rotary magnetorheological damper. The magnetorheological damper can suppress the high vibration energy in resonance frequency, and then a small active force can further improve the seat suspension performance greatly. The suspension’s dynamic property is tested with a MTS system, and its model is identified based on the testing data. A modified on–off controller is applied for the rotary magnetorheological damper. A [Formula: see text] controller with the compensation of a disturbance observer is used for the active actuator. Considering the energy saving, the control strategy is designed as that only when the magnetorheological damper is in the off state (0 A current), the active actuator will have active force output, or the active actuator is off. Both simulation and experiment are implemented to verify the proposed seat suspension and controller. In the sinusoidal excitations experiment, the acceleration transmissibility of integrated control seat has lowest value in resonance frequency and frequencies above the resonance, when compared with power on (0.7 A current), power off (0 A current) and semi-active control seat. In the random vibration experiment, the root mean square acceleration of integrated control seat suspension has 47.7%, 33.1% and 26.5% reductions when compared with above-mentioned three kinds of seat suspension. The power spectral density comparison indicates that the integrated seat suspension will have good performance in practical application. The integrated active and semi-active seat suspension can fill energy consumption gap between active and semi-active control seat suspension.

scholarly journals Design and multi-physics optimization of a novel magnetorheological damper with a variable resistance gap

2016 ◽  
Vol 231 (17) ◽  
pp. 3152-3168 ◽  
Author(s):  
Jiajia Zheng ◽  
Yancheng Li ◽  
Jiong Wang
Keyword(s):  
Optimization Problem ◽  
Dynamic Range ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Voltage Source ◽  
Damping Force ◽  
Variable Resistance ◽  
Design Variables ◽  
Electromagnetic Coils ◽  
Vibration Performance

This paper presents the design and multi-physics optimization of a novel multi-coil magnetorheological (MR) damper with a variable resistance gap (VRG-MMD). Enabling four electromagnetic coils (EMs) with individual exciting currents, a simplified magnetic equivalent circuit was presented and the magnetic flux generated by each voltage source passing through each active gap was calculated as vector operations. To design the optimal geometry of the VRG-MMD, the multi-physics optimization problem including electromagnetics and fluid dynamics has been formulated as a multi-objective function with weighting ratios among total damping force, dynamic range, and inductive time constant. Based on the selected design variables (DVs), six cases with different weighting ratios were optimized using Bound Optimization BY Quadratic Approximation (BOBYQA) technique. Finally, the vibration performance of the optimal VRG-MMD subjected to sinusoidal and triangle displacement excitations was compared to that of the typical multi-coil MR damper.

Self-powered magnetorheological dampers for motorcycle suspensions

2017 ◽  
Vol 232 (7) ◽  
pp. 921-935 ◽  
Author(s):  
Chao Chen ◽  
Yu Shing Chan ◽  
Li Zou ◽  
Wei-Hsin Liao
Keyword(s):  
Laboratory Testing ◽  
Ride Comfort ◽  
Mechanical Energy ◽  
The Self ◽  
Magnetorheological Damper ◽  
System Level ◽  
Magnetorheological Dampers ◽  
Suspension Systems ◽  
Magnetorheological Suspension ◽  
Self Powered

Dampers are the parts of suspensions which improve the ride comfort and the safety of vehicles including motorcycles. Magnetorheological dampers are very attractive for motorcycle suspensions, because of their controllable properties and their fast responses. Considerable energy is wasted owing to the energy dissipation by dampers encountering road irregularities and accelerating processes during everyday use of motorcycles. In addition, the current magnetorheological suspension systems depend on the power supply of batteries. Therefore, in this paper, a self-powered magnetorheological damper for motorcycle suspensions is proposed and implemented for the first time. It can convert the wasted mechanical energy into useful electrical energy to power itself. There are great merits in this such as energy saving, independence of extra batteries and less maintenance in comparison with conventional magnetorheological suspension systems, while keeping controllable performances. A customized prototype of the self-powered magnetorheological damper that is compatible with a motorcycle is developed and actually implemented in a motorcycle. Modelling for the self-powered magnetorheological damper is developed and validated by laboratory testing. Laboratory testing showed that the self-powered feature works well to generate the electrical power and to vary the magnetorheological damping force. Preliminary system-level testing showed that a self-powered magnetorheological suspension results in a better ride comfort, compared with that of a magnetorheological suspension without power generation. The results showed that implementing self-powered magnetorheological dampers in motorcycle suspensions is feasible and beneficial.

scholarly journals Methods for controlling the elastic damping characteristics of pneumatic seat suspensions

2021 ◽  
Vol 1 (2) ◽  
pp. 27-33
Author(s):  
M.V. Lyashenko ◽  
◽  
V.V. Shekhovtsov ◽  
P.V. Potapov ◽  
A.I. Iskaliyev ◽  
...  
Keyword(s):  
Vibrational Energy ◽  
Working Fluid ◽  
Technical Solution ◽  
Technical Literature ◽  
Seat Suspension ◽  
Suspension Systems ◽  
Damping Characteristics ◽  
Air Suspension ◽  
Wide Range ◽  
Vehicle Seat

The pneumatic seat suspension is one of the most important, and in some situations, one of the key components of the vibration protection system for the human operator of the vehicle. At the present stage of scientific and technical activities of most developers, great emphasis is placed on controlled seat suspension systems, as the most promising systems. This article analyzes the methods of controlling the elastic damping characteristics of the air suspension of a vehicle seat. Ten dif-ferent and fairly well-known methods of changing the shape and parameters of elastic damping characteristics due to electro-pneumatic valves, throttles, motors, additional cavities, auxiliary mechanisms and other actuators were considered, the advantages, application limits and disad-vantages of each method were analyzed. Based on the results of the performed analytical procedure, as well as the recommendations known in the scientific and technical literature on improving the vibration-protective properties of suspension systems, the authors proposed and developed a new method for controlling the elastic-damping characteristic, which is implemented in the proposed technical solution for the air suspension of a vehicle seat. The method differs in the thing that it im-plements a cyclic controlled exchange of the working fluid between the cavities of the pneumatic elastic element and the additional volume of the receiver on the compression and rebound strokes, forming an almost symmetric elastic damping characteristic, and partial recuperation of vibrational energy by a pneumatic drive, presented in the form of a rotary type pneumatic motor. In addition, the method does not require an unregulated hydraulic shock absorber, while still having the ad-vantage of improved vibration-proof properties of the air suspension of a vehicle seat over a wide range of operating influences.

scholarly journals MR Damper-Based Vibration Suppression Method for Control Moment Gyroscope

2018 ◽  
Vol 36 (5) ◽  
pp. 884-889
Author(s):  
Wendong Wang ◽  
Xing Ming ◽  
Yang Chu ◽  
Minghui Liu ◽  
Yikai Shi
Keyword(s):  
Active Control ◽  
Control Algorithm ◽  
Vibration Suppression ◽  
Control Method ◽  
Magnetorheological Damper ◽  
Magnetic Flux Density ◽  
Damping Force ◽  
Control Moment Gyroscope ◽  
Control Moment ◽  
Suppression Method

To restrain the interference of micro-vibration caused by Control Moment Gyroscope, a new control method based on Magnetorheological damper was proposed in this paper. A mechanical model based on the structure of the presented design was built, and the semi-active control algorithm of damping force was proposed for the designed Magnetorheological damper. The magnetic flux density and other magnetic field parameters were considered and analyzed in Maxwell, and also the related hardware circuit which implements the control algorithm was prepared to test the presented design and algorithm. The results of simulation and experiments show that the presented Magnetorheological damper model and semi-active control algorithm can complete the requirements, and the vibration suppression method is efficient for Control Moment Gyroscope.

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