KINETO-DYNAMIC PADA VARIABLE GEOMETRY SUSPENSION (VGS)

Suspension technology on the vehicle provides a comforting effect with shock absorbers and a safety effect in driving and reducing the accident rate. The suspension system was developed by changing the construction and mechanism as well as the addition of a control element. Variable Geometry Suspension (VGS) is the development of a suspension system by using an active actuator is Single-link which is used to change the geometry of the suspension. Geometry change can affect the performance of the suspension system, so a modeling approach is needed to analyze the performance of the VGS system. The VGS modeling uses a quarter-vehicle model and a multi-body model with an equation of motion system using a Kineto-dynamic model with a double-wishbone suspension type. The analysis method on the VGS uses input is bumpy-road to obtain system performance in body acceleration, suspension deflection, and tire deformation. The results of the VGS with the Kineto-dynamic model has a range of 2 mm in the variation of the single-link angle, the performance values ​​in the body acceleration and tire deformation between the quarter-vehicle and multi-body models have the same oscillations until steady, while the suspension deflection in the Kineto-dynamic model differs in the first oscillation with a steady time of 1.6 seconds. Therefore, the Kineto-dynamic model can be used to approximate the actual system

Nonlinear vibration of a dipteran flight robot system with rotational geometric nonlinearity

The dipteran flight mechanism of the insects is commonly used to design the nonlinear flight robot system. However, the dynamic response of the click mechanism of the nonlinear robot system with multiple stability still unclear. In this paper, a novel dipteran robot model with click mechanism proposed based on the multiple stability of snap-through buckling. The motion of equation of the nonlinear flight robot system is obtained by using the Euler-Lagrange equation. The nonlinear potential energy, the elastic force, equilibrium bifurcation, as well as equilibrium stability are investigated to show the multiple stability characteristics. The transient sets of bifurcation and persistent set of regions in the system parameter plane and the corresponding phase portraits are obtained with multiple stability of single and double well behaviors. Then, the periodic free vibration response are defined by the analytical solution of three kinds of elliptical functions, as well as the amplitude frequency responses are investigated by numerical integration. Based on the topological equivalent method, the chaotic thresholds of the homo-clinic orbits for the chaotic vibration of harmonic forced robot system are derived to show the chaotic parametric condition. Finally, the prototype of nonlinear flapping robot is manufactured and the experimental system is setup. The nonlinear static moment of force curves, periodic response and dynamic flight vibration of dipteran robot system are carried out. It is shown that the test results are agree well with the theoretical analysis and numerical simulation. Those result have the potential application for the structure design of the efficient flight robot.Comment: 30 pages, 24 figur

Parallel active link suspension: full car application with frequency-dependent multi-objective control strategies

In this article, a recently proposed at basic level novel suspension for road vehicles, the parallel active link suspension (PALS), is investigated in the realistic scenario of a sport utility vehicle (SUV) full car. The involved rocker-pushrod assembly is generally optimized to maximize the PALS capability in improving the suspension performance. To fully release the PALS functions of dealing with both low- and high-frequency road cases, a PID control scheme is first employed for the chassis attitude stabilization, focusing on the minimization of both the roll and pitch angles; based on a derived linear equivalent model of the PALS-retrofitted full car, an H∞ control scheme is designed to enhance the ride comfort and road holding; moreover, a frequency-dependent multiobjective control strategy that combines the developed PID and H∞ control is proposed to enable: 1) chassis attitude stabilization at 0-1 Hz; 2) vehicle vibration attenuation at 1-8 Hz; and 3) control effort penalization (for energy saving) above 10 Hz. With a group of ISO-defined road events tested, numerical simulation results demonstrate that, compared to the conventional passive suspension, the PALS has a promising potential in full-car application, with up to 70% reduction of the chassis vertical acceleration in speed bumps and chassis leveling capability of dealing with up to 4.3-m/s² lateral acceleration

MATHEMATICAL MODELLING OF THE PASSIVE AND SEMI-ACTIVE AUTOMOBILE SUSPENSION SYSTEMS IN FORD SCORPIO CAR MODEL

The suspension is a system of spring or shock absorbers connecting the wheels and axles at the chassis of a vehicle. In this study, Ford Scorpio car with passive and semi-active suspension system are formulated using Second Order Differential Equations (ODE). These models were solved analytically using the undetermined coefficient and Cramer rule methods. The comparison between passive and semi-active suspension system also conducted to measure such as displacement, frequency and time by plotting graphs. The passive system resulted that a constant displacement roughly at 0.035 m while 0.025 m was obtained by a semi-active suspension system. Semi-active system took t = 1 s to yield a constant displacement while for the passive suspension system required t = 1.5 s. The comparison showed the semi-active results were better than a passive suspension system

Mathematical Modelling Of The Passive And Semi-Active Automobile Suspension Systems In Ford Scorpio Car Model

The suspension is a system of spring or shock absorbers connecting the wheels and axles at the chassis of a vehicle. In this study, Ford Scorpio car with passive and semi-active suspension system are formulated using Second Order Differential Equations (ODE). These models were solved analytically using the undetermined coefficient and Cramer rule methods. The comparison between passive and semi-active suspension system also conducted to measure such as displacement, frequency and time by plotting graphs. The passive system resulted that a constant displacement roughly at 0.035 m while 0.025 m was obtained by a semi-active suspension system. Semiactive system took t = 1 s to yield a constant displacement while for the passive suspension system required t = 1.5 s. The comparison showed the semi-active results were better than a passive suspension system

Quarter-car experimental study for series active variable geometry suspension

In this paper, the recently introduced series active variable geometry suspension (SAVGS) for road vehicles is experimentally studied. A realistic quarter-car test rig equipped with double-wishbone suspension is designed and built to mimic an actual grand tourer real axle, with a single-link variant of the SAVGS and a road excitation mechanism implemented. A linear equivalent modeling method is adopted to synthesize an H-infinity control scheme for the SAVGS, with the geometric nonlinearity compensated. Simulations with a theoretical nonlinear quarter-car indicate the SAVGS potential to enhance suspension performance, in terms of ride comfort and road holding. Practical features in the test rig are further considered and included in the nonlinear model to compensate the difference between the theoretical and testing behaviors. Experiments with a sinusoidal road, a smoothed bump and hole, and a random road are performed to evaluate the SAVGS practical feasibility and performance improvement, the accuracy of the model, and the robustness of the control schemes. Compared with the conventional passive suspension, ride comfort improvements of up to 41% without any deterioration of the suspension deflection are demonstrated, while the SAVGS actuator power is kept very low, at levels below 500 W

Analisis Dinamis pada Variable Geometry Suspension (VGS) dengan Kendali LQR dan LQG

Perkembangan teknologi pada suspensi kendaraan bertujuan untuk memberikan efek kenyamanan dan keamanan dalam berkendara. Sistem suspensi dengan komponen aktif telah dikembangkan mulai dari sistem suspensi semi-aktif hingga aktif. Variable Geometry Suspension (VGS) merupakan pengembangan dari sistem suspensi yang menggunakan aktuator aktif (single-link) berupa poros cam yang dipasang secara seri dengan suspensi. Penelitian ini bertujuan untuk mengetahui performa dari VGS menggunakan kendali Linear Quadratic Regulator (LQR) dan Linear Quadratic Gaussian (LQG). Sistem suspensi dimodelkan dengan model kineto-dynamic. Metode linear equivalent modelling dan pemodelan state-space digunakan untuk mendesain sistem kendali dari VGS. LQR adalah kendali yang mengasumsikan semua state dapat diukur (full-state feedback), sedangkan LQG merupakan pengembangan dari LQR yang memiliki estimator/observer pada sistemnya, sehingga hanya memerlukan beberapa pengukuran saja. Penelitian ini memvariasikan nilai pembobotan pada LQR sedangkan pada LQG memvariasikan jumlah pengukuran (sensor) yang digunakan. Analisis performa dengan meninjau nilai RMS (root mean square) dan nilai Comfort Gain dari sistem VGS pada masing-masing kendali. Hasil penelitian ini didapatkan bahwa sistem VGS dengan model multi-bodi menggunakan kendali LQR dan LQG lebih baik dari sistem pasif. Pada kendali LQR, didapatkan nilai RMS maksimal sebesar 0,26 m/s2 pada percepatan sprung-mass, sedangkan kendali LQG sebesar 1,22 m/s2 dengan pengukuran kondisi III (sensor percepatan bodi dan defleksi suspensi). Nilai RMS dari defleksi suspensi dengan kendali LQR dan LQG tidak lebih baik dari sistem pasif, sedangkan pada deformasi ban nilai RMS dengan kendali LQR maksimal sebesar 6,6 mm dan pada LQG berkisar 6,7 sampai 6,8 mm. Nilai Comfort Gain dari sistem VGS mencapai 89,65% pada LQR dan 51,84% dengan kendali LQG, sedangkan pada nilai deformasi ban sebesar 3,17% pada LQR dan LQG sebesar 2,25%. ======================================================================================================================== Technological developments in vehicle suspension aim to provide comfort and safety. A suspension system with active components has been developed such as semi-active and active system. Variable Geometry Suspension (VGS) is a kind of active suspension that uses active actuators (single-link) in the form of a cam-axle mounted in series with the spring damper components. This paper report the study of the performance of VGS with Linear Quadratic Regulator (LQR) and Linear Quadratic Gaussian (LQG) control. First, a kineto-dynamic model is developed then a linear equivalent model in the state-space form is derived to design the controller. LQR is a control that assumes all states can be measured (full-state feedback). For LQG control the 2 cases of measurement combination with commonly available sensor are considered. The dynamics analysis of the VGS is conducted using multi-body dynamics model to capture the non-linear phenomena of the real system. This study varied the weighting in LQR, whereas LQG varied the number of measurements (sensors) used. Performance analysis by reviewing the RMS (root mean square) and Comfort Gain of the VGS system on each control. The simulation results of VGS system with multi-body model using LQR and LQG control batter than passive system. In LQR control, the maximum RMS is 0.26 m/s2 on sprung-mass acceleration, while the LQG control is 1.22 m/s2 with the acceleration sensor body and suspension deflection measurement. The RMS of the suspension deflection with LQR and LQG controls is no better than the passive system, whereas for tire deformation on LQR control of 6.6 mm and in the LQG ranges from 6.7 to 6.8 mm. Comfort Gain from VGS system reached 89.65% in LQR and 51.84% with LQG control, while the tire deformation value was 3.17% at LQR and LQG of 2.25%