Suspension Test Rig Research Articles

Design and Analysis of Suspension Test Rig

Design and Analysis of Suspension Test Rig

Decoupled adaptive terminal sliding mode control strategy for a 6-DOF electro-hydraulic suspension test rig with RBF coupling force compensator

Aiming at the problems of poor tracking accuracy, low convergence speed, weak robustness of a 6-DOF electro-hydraulic suspension test system under system uncertainties and external disturbance, this article proposes double closed-loop control scheme. In the outer loop controller, this article designs a new decoupled adaptive fast nonsingular terminal sliding mode (DAFNTSM) control to achieve fast convergence rate, high accurate and adaptive disturbances estimation during trajectory tracking. Additionally, a coupling force compensator based on RBF neural network is employed, which can reduce online calculation quantity and guarantee accuracy. For six inner loop controllers, each hydraulic actuator can precisely follow the required force solved by outer loop controller. The hard-in-loop experiment results reveal that the control approach we proposed in this paper realize superior trajectory tracking characteristics in comparison with the conventional nonsingular terminal sliding mode (CNTSM) method.

Reliable Fuzzy Sampled-Data Control for Nonlinear Suspension Systems Against Actuator Faults

This article investigates the reliable fuzzy sampled-data control issue of nonlinear vehicle suspension systems subject to actuator faults. Considering the high nonlinear characteristics in the springs and the shock absorbers, the Takagi–Sugeno fuzzy method is utilized to describe the nonlinear suspension system. To deal with the discrete phenomenon of nonuniform sampling, an input-delay is employed to convert the continuous-discrete suspension system into a continuous-time form. Motivated by the above system model, a Lyapunov functional candidate is employed to obtain sufficient conditions that can meet system stability and performance requirements simultaneously. Furthermore, a novel two-step optimization algorithm is proposed for the sampled-data controller design in the structure of output feedback. Finally, experimental tests are implemented via an active suspension test rig, and the test results illustrate that the proposed method contributes greatly to improve the ride comfort, handling performance, and road holding capability simultaneously.

Active Suspension Control of Quarter-Car System With Experimental Validation

A reliable, efficient, and simple control is presented and validated for a quarter-car active suspension system equipped with an electro-hydraulic actuator. Unlike the existing techniques, this control does not use any function approximation, e.g., neural networks (NNs) or fuzzy-logic systems (FLSs), while the unmolded dynamics, including the hydraulic actuator behavior, can be accommodated effectively. Hence, the heavy computational costs and tedious parameter tuning phase can be remedied. Moreover, both the transient and steady-state suspension performance can be retained by incorporating prescribed performance functions (PPFs) into the control implementation. This guaranteed performance is particularly useful for guaranteeing the safe operation of suspension systems. Apart from theoretical studies, some practical considerations of control implementation and several parameter tuning guidelines are suggested. Experimental results based on a practical quarter-car active suspension test-rig demonstrate that this control can obtain a superior performance and has better computational efficiency over several other control methods.

자기 베어링용 동위 와전류 변위 센서

Magnetic bearings use electromagnetic force to support the rotating shaft without any mechanical contact and actively control shaft vibration; hence, there is no mechanical friction and wear due to contact during the operation, and it has a semi-permanent lifespan. Because magnetic bearings are unstable by themselves, a gap sensor is necessary to stably control the position of objects. However, there is a limit to the improvement in control performance because the sensor is installed on one side of the bearing and is not aligned with the electromagnet. This paper presents a newly developed collocated eddy-current PCB displacement sensor for magnetic bearings. The PCB sensor is designed and built to install between the poles of a magnetic bearing and to minimize the electromagnetic interference. A sensor calibration test is performed to evaluate the sensitivity and noise of the collocated PCB sensor. In addition, the control performance of the collocated PCB sensor is evaluated by measuring the closed-loop sensitivity function of a 1 DOF magnetic suspension test rig. The collocated PCB sensor has noise within ±1 μm and excellent vibration suppression performance.

Design of vibration damping test mechanism for suspension system of high speed tracked vehicle based on vertical linkage decoupling

The suspension test-rig is restricted by the compound swing motion of the load wheel in a high-speed tracked vehicle, and cannot test the damping performance for the suspension system of the high-speed tracked vehicle with the track. A vibration damping testing mechanism using vertical linkage to decouple the compound swing motion of the load wheel is proposed for suspension performance testing with the track. Using Hertz elastic contact theory to solve the stiffness coefficient between load wheel and excitation wheel, a virtual prototype model for vibration damping test mechanism with vertical linkage is established in ADAMS. Correctness of the virtual prototype model is verified by experiment. The motion decoupling ability of the vibration damping testing mechanism is verified by simulation. The dynamic characteristics for each pair of guide and slider in vibration damping testing mechanism are analyzed under the condition of maximum excitation force and displacement, and the selection criteria of slider and guide contained in the motion pair components are acquired. The mechanism decouples the compound swing motion of the load wheel successfully, and can make suspension system performance testing in high-precision for the high-speed tracked vehicle with track realized, playing an important role in parameters design and performance optimization for the high-speed tracked vehicle.

CONTROL AND EXPERIMENTAL EVALUATION ON A QUARTER-CAR TEST RIG

In this paper a quarter-vehicle full-scale suspension test rig was designed and manufactured,the suspension is considered semi-active as the electrohydraulic (EH) damper used is fullycontrolled. This gives an indoor-based simulation tool which is important for vehicle testing;.This reduces the cost significantly with accurate results, especially when designing a newsuspension system. The aim of the current work was to build a new quarter-vehicle test rigwith expandable capabilities for diverse design objectives, also may be used for academicpurposes. The control objective was achieved by using dynamic characteristics of theelectrohydraulic (EH) damper to suppress the oscillation of the sprung mass due to roadirregularities. The test rig was constructed using a Genesis G80 (2016) suspension system.Finally, the simulation results demonstrated that the proposed controller used be able toefficiently regulate the chassis vertical oscillation under these irregularities. The experimentalresults for the quarter-car model showed good results between experimental and simulatedresults, where the proportion of conformity about 95%

E CONTROL AND EXPERIMENTAL EVALUATION ON A QUARTER-CAR TEST RIG

In this paper a quarter-vehicle full-scale suspension test rig was designed and manufactured,the suspension is considered semi-active as the electrohydraulic (EH) damper used is fullycontrolled. This gives an indoor-based simulation tool which is important for vehicle testing;.This reduces the cost significantly with accurate results, especially when designing a newsuspension system. The aim of the current work was to build a new quarter-vehicle test rigwith expandable capabilities for diverse design objectives, also may be used for academicpurposes. The control objective was achieved by using dynamic characteristics of theelectrohydraulic (EH) damper to suppress the oscillation of the sprung mass due to roadirregularities. The test rig was constructed using a Genesis G80 (2016) suspension system.Finally, the simulation results demonstrated that the proposed controller used be able toefficiently regulate the chassis vertical oscillation under these irregularities. The experimentalresults for the quarter-car model showed good results between experimental and simulatedresults, where the proportion of conformity about 95%.

Vibration control of FSAE quarter car suspension test rig using magnetorheological damper

Recently MRF damper -which has a significant controllable damping force - used frequently in many active and semi-active suspension systems. However, MRF damper needs controller to estimate the desired force to dissipate the occurred vibration instantaneously. PID controller is one of the effective feedback controllers which shows robustness and simplicity in control MRF dampers, but still the parameters of the PID controller under study to find out the optimum values. This study focused on the vibration control using Magneto-rheological (MR) damper on a FSAE quarter car suspension test rig to study and obtain the optimum running condition. The test rig was designed, modified and then tested using a P-controller integrated with MR damper, unbalance mass used as disturbance and analyzed using LABVIEW software in time and frequency domains. The natural frequency obtained was 2.2 Hz were similar to the actual FSAE car natural frequency. Based on the acceleration against time graph with different proportional gain value the optimal value for proportional gain, Kp was 1. Hence, the experiment work could be used as the initial stage to study and develop a robust controller to suppress vibration on a car.

Takagi-Sugeno Fuzzy Model-Based Semi-Active Control for the Seat Suspension With an Electrorheological Damper

Numerous research studies have been performed to help develop advanced control algorithms for semi-active seat suspension. This paper experimentally investigates a state observer-based Takagi-Sugeno (T-S) fuzzy controller for a semi-active seat suspension by equipping an electrorheological (ER) damper. A new ER damper prototype is designed, assembled, and tested. Then, a T-S fuzzy model is established to describe the ER seat suspension, which can facilitate the H∞ controller design considering the multiobjective optimization. A state observer is established and integrated into the controller to estimate the state information for the T-S fuzzy model in real-time. Additionally, the experimental validation of the control algorithm is critical in the practical application. A seat suspension test rig is built to validate the effectiveness of the proposed controller. The presented control algorithm is evaluated by comparing the corresponding test results to those with a skyhook controller. The experimental results demonstrate that the proposed T-S fuzzy control method, compared to the traditional control method, can further improve the performance of an ER seat suspension system.

Multibody model based estimation of multiple loads and strain field on a vehicle suspension system

Abstract This work proposes an augmented extended Kalman filter based state-input estimator for mechanical systems defined by implicit equations of motion which is then applied to estimate the six wheel center loads and the strain field on a vehicle suspension test rig. Implicit equations of motion typically arise in the definition of flexible multibody models and also in their time resolution, because implicit time-discretization schemes are normally employed to obtain a stable solution. The presented methodology can be applied to such case and analytical expressions are derived for the necessary linearizations, providing the means for a computationally efficient estimation procedure. The six wheel center loads and the strain field on a vehicle suspension system are valuable quantities during the vehicle design phase (e.g. for durability analysis), hence they are often directly measured during elaborate full vehicle testing campaigns. This work demonstrates that a flexible multibody model representation allows to accurately reconstruct the time domain signals of the six loads and of the full strain field, starting from a minimal set of six measured strains, hence providing an appealing alternative to direct measurement methods. The experimental validation on the suspension test rig shows that all estimated quantities can be accurately reconstructed, given that the system simulation model incorporates an adequate level of accuracy.

Research on the Design Method of a Bionic Suspension Workpiece Based on the Wing Structure of an Albatross.

An air suspension platform uses air pressure to realize the suspension function during the suspension process, and it has the disadvantage of large air pressure and a small suspension force. In this study, an air suspension platform was built using bionic design to reduce the required air pressure and increase the suspension force. A suspension structure mapping model was established according to the physiological structure characteristics of albatross wings. A bionic model was established by using the theoretical calculation formula and structural size parameters of the structural design. A 3D printer was used to manufacture the physical prototype of the suspended workpiece. Based on this, a suspension test rig was built. Six sets of contrast experiments were designed. The experimental results of the suspension test bench were compared with the theoretical calculation results. The results show that the buoyancy of the suspended workpiece with a V-shaped surface at a 15-degree attack angle was optimal for the same air pressure as the other workpieces. The surface structure of the suspended workpiece was applied to the air static pressure guide rail. By comparing the experimental data, the air pressure of the original air suspension guide rail was reduced by 37%, and the validity of the theory and design method was verified.

Modelling, validation and characterisation of high-performance suspensions by means of a suspension test rig

To meet the high demands and expectations on ride comfort and handling, detailed analysis of the vibrational behaviour of suspension systems is required. Therefore, component modelling and testing, as well as full vehicle tests, go hand in hand. The present study addresses possible benefits, when a suspension test rig is available, and howit may be used to analyse and characterise the vibrational behaviour of particular, isolated suspensions. Respective synthetic excitation spectra map the dynamic behaviour of the suspension from full vehicle tests. Component models are presented that show a reasonable compromise between modelling and parametrisation effort. Utilising the suspension test rig revealed that frictional effects must be considered when assembling the components to a full suspension model. Further, modal properties of the tested high-performance suspensions become obvious, that may allow for comparison with follow-up, similar suspensions. Finally, the suspension models are evaluated with full vehicle tests.

Modelling, validation and characterisation of high-performance suspensions by means of a suspension test rig

To meet the high demands and expectations on ride comfort and handling, detailed analysis of the vibrational behaviour of suspension systems is required. Therefore, component modelling and testing, as well as full vehicle tests, go hand in hand. The present study addresses possible benefits, when a suspension test rig is available, and howit may be used to analyse and characterise the vibrational behaviour of particular, isolated suspensions. Respective synthetic excitation spectra map the dynamic behaviour of the suspension from full vehicle tests. Component models are presented that show a reasonable compromise between modelling and parametrisation effort. Utilising the suspension test rig revealed that frictional effects must be considered when assembling the components to a full suspension model. Further, modal properties of the tested high-performance suspensions become obvious, that may allow for comparison with follow-up, similar suspensions. Finally, the suspension models are evaluated with full vehicle tests.

Hardware-in-the-Loop Simulation for a Multiaxial Suspension Test Rig with a Nonlinear Spatial Vehicle Dynamics Model

Hardware-in-the-Loop (HiL) simulations where a mechatronic system is used as the device under test (DUT), are established in the automotive sector for the design of active suspension components, e.g. roll-stabilizers. Usually, uniaxial actuator systems within the test rig are applied for the excitation of the DUT. However, in the context of mechatronic suspension systems incorporating multiple mechatronic subsystems, more sophisticated HiL test rigs / simulations with multiaxial excitation of the DUT are necessary. This contribution presents the model-based design of a HiL simulation for a multiaxial vehicle axle test rig. Within the HiL simulation a nonlinear spatial vehicle dynamics model with 36 states is used to reproduce the environment of the DUT in real-time. The implemented model and its requirements are described in detail. An appropriate HiL control framework is developed, which combines the vehicle dynamics model with the hybrid motion/force control of the manipulator systems. The primary actuator is a hydraulic hexapod. Simulation results and measurements obtained with the HiL system show the effectiveness of this approach. The potential for chassis control validation and design is highlighted in comparison to a highly detailed benchmark vehicle dynamics model.

Experimental design, sensitivity analysis of steering geometry and suspension parameters

The main aim of this study is to evaluate the individual and interactive impact of steering geometry and suspension parameters on ride comfort and road holding throughout the predetermined loading range. A series of experimental runs were taken on a quarter car suspension test rig and the readings were analyzed by implementing the fractional factorial method of DOE. Regression analysis and ANOVA quantified the nature and extent of the relative influences of each of these factors and their interactions. Compared to ride comfort, it was found that a lot of interactions involving the steering geometry variables had a significant impact up on road holding. Eventually, a multi-objective model for evaluating ride comfort and road holding on the basis of various parameters was proposed. The main effects and interaction plots were plotted and corresponding inferences were verified by plotting contour and surface plots of the significant interactions for both ride comfort and road holding.

A universal suspension test rig for electrohydraulic active and passive automotive suspension system

A fully active electro-hydraulic and passive automotive quarter car suspensions with their experimental test-rigs are designed and implemented. Investigation of the active performance compared against the passive is performed experimentally and numerically utilizing SIMULINK's Simscape library. Both systems are modeled as single-degree-of-freedom in order to simplify the validation process. Economic considerations were considered during the rig's implementation. The rig consists of two identical platforms fixed side by side allowing testing two independent suspensions simultaneously. Position sensors for sprung and unsprung masses on both platforms are installed. The road input is introduced by a cam and a roller follower mechanism driven by 1.12kW single phase induction motor with speed reduction assembly. The active hydraulic cylinder was the most viable choice due to its high power-to-weight ratio. The active control is of the proportional-integral-differential (PID) type. Though this technique is quite simple and not new, yet the emphasis of this paper is the engineering, design and implementation of the experimental setup and controller. A successful validation process is performed. Ride comfort significantly improved with active suspension, as shown by the results; 24.8% sprung mass vibration attenuation is achieved. The details of the developed system with the analytical and experimental results are presented.

Experimental Study on the Dynamic Characteristics of Hydro-Magneto-Electric-Regenerative Shock Absorber

Regenerative shock absorber is designed to convert the vibration energy losses from the vehicle suspension into electricity. This paper presents an experimental study on the dynamic characteristics of hydro-magneto-electric-regenerative shock absorber (HMERSA). Study was carried out by developing a prototype of HMERSA and testing its dynamic characteristics. The results were analyzed and discussed. Prototype of the HMERSA consists of hydraulic system and electric generator. The HMERSA was tested using a quarter car suspension test rig with input displacement in various frequency (1.3Hz, 1.5Hz, 1.7Hz) and for HMERSA’s various oil viscousity (ISO VG 10, 32, 46). Sprung mass acceleration and the generated electric power representing the dynamic characteristics of HMERSA were measured. Maximum power 2.5 watt and root mean square acceleration 0.172 m/s2 gained for HMERSA with oil viscousity ISO VG 10 at all excitation frequency.

A new method for studying the longitudinal dynamic behaviour of a suspension on a test rig

Analysing the dynamic behaviour of a suspension is essential to achieve the best relationship possible between the ride comfort and the handling. In the past, much effort was spent in investigating the dynamic transmission behaviour of a suspension on a test rig. The majority of these test rigs allow only a vertical deflection. However, the longitudinal direction becomes increasingly important when optimizing the ride comfort on uneven roads. This study investigates the various possibilities for identifying the longitudinal dynamic behaviour and the bump sensitivity of a suspension, by means of a completely rigid clamp acting on a motionless tyre or a stiff dummy wheel. Furthermore, excitations superimposed on the suspension are investigated in detail followed by a parameter study to discover their influence on the longitudinal transmission behaviour of the suspension. Additionally, the results of multi-body simulations are compared with the real measurements. The adopted approach enables the influences of different suspension parameters to be analysed and evaluated on a real suspension test rig and a virtual suspension test rig, in connection with a tyre or for a stand-alone axle.

Friction compensation using Coulomb friction model with zero velocity crossing estimator for a force controlled model in the loop suspension test rig

This paper presents a method of friction compensation for a linear electric motor in a model in the loop suspension test rig. The suspension consists of a numerically modeled spring and damper, with inputs of suspension motion. The linear motor is force controlled using a force sensor to track the output of the numerical model. The method uses a Coulomb friction model and applies a feedforward step signal when velocity zero crossing occurs. Velocity zero crossing estimation is achieved using an algorithm based on measured feedback velocity and force. Experimental results indicate reduction of force tracking error caused by Coulomb friction leading to improved test rig accuracy.