The ride comfort and energy-regenerative characteristics analysis of hydraulic-electricity energy regenerative suspension

For optimization of performances of a hydraulic-electricity energy regenerative suspension (HERS) unit, the tradeoff point was determined based on study of ride comfort and energy-regenerative characteristics of a HERS unit in this study. A HERS unit as a new energy reclaiming suspension device is equipped with an energy-harvesting hydraulic electromagnetic shock absorber (HESA). The HESA together with a quarter car was modeled based on theoretical analysis and experiments, in which the root mean square (RMS) values of the sprung mass vibration acceleration and the recovered power are regarded as the optimization objectives under different road excitation conditions such as the constraints (natural frequency, dynamic displacement, and dynamic load of wheels). The HERS unit was optimized after the relationship between the ride comfort and the energy regeneration was obtained. In comparison with the traditional suspension, the HERS unit may be utilized to improve the ride comfort and meet the vehicle-driving requirements. Moreover, the total input power may be saved by 34-100 W on average while the vibration acceleration is among 0.65-1.06 m/s2. Furthermore, it is verified that the HERS damping force control is the feasible under various load currents

The net power control of hydraulic-electricity energy regenerative suspension

For achieving the control of hydraulic-electricity energy regenerative suspension (HERS), a novel control algorithm, net power control (NPC), is applied in this study. A HERS unit as a new energy reclaiming suspension device is equipped with an energy-harvesting hydraulic-electricity shock absorber (HESA). The composition and classification of HESA damping force were analyzed based on the basic working principle of HESA. Thus, the mathematical model of HESA damping force is deduced as a function of suspension dynamic speed and load current. A series of experiments were made to verify the reliability of the model. Based on the energy flow analysis of the suspension system, the net power flowing into the suspension is calculated. In order to minimize the vibration acceleration of the vehicle body, a novel net power control is proposed. The comparison result indicates the control effect of NPC is more significant than skyhook control, especially in the high excitation frequency. Also, the HERS bench test was carried out to verify the feasibility of NPC. The related results show that the maximum acceleration of the vibration is improved by 34.23 % with NPC on bump pavement excitation. And on B-class random road, the root mean square (RMS) value of the sprung mass vibration acceleration is reduced by 65 %. Furthermore, the influence of suspension dynamic velocity and deflection on the optimal control load current is obtained

Design, Modeling, and Analysis of a Novel Hydraulic Energy-Regenerative Shock Absorber for Vehicle Suspension

To reduce energy consumption or improve energy efficiency, the regenerative devices recently have drawn the public’s eyes. In this paper, a novel hydraulic energy-regenerative shock absorber (HERSA) is developed for vehicle suspension to regenerate the vibration energy which is dissipated by conventional viscous dampers into heat waste. At first, the schematic of HERSA is presented and a mathematic model is developed to describe the characteristic of HERSA. Then the parametric sensitivity analysis of the vibration energy is expounded, and the ranking of their influences is k1≫m2>m1>k2≈cs. Besides, a parametric study of HERSA is adopted to research the influences of the key parameters on the characteristic of HERSA. Moreover, an optimization of HERSA is carried out to regenerate more power as far as possible without devitalizing the damping characteristic. To make the optimization results more close to the actual condition, the displacement data of the shock absorber in the road test is selected as the excitation in the optimization. The results show that the RMS of regenerated energy is up to 107.94 W under the actual excitation. Moreover it indicates that the HERSA can improve its performance through the damping control

Modeling of Human Skin by the Use of Deep Learning

Deep learning (DL) has matured well over time and resonated in various domains of computer applications. Pattern recognition gets more attention in machine learning field to take advantage of data available for modern life. Recognition by using the technology performance is worthy in terms of skin and other human features; this research tries to extract useful features from the skin and then classify these features under certain condition. The main objective of this study is to detect the skin diseases early and classify them for correct treatment. Using improved classifier (ISVM) to be adaptive with requirements of our task, many advantages can be got with this technique and it is useful in the fields of medicine, human health care, and diagnosis and life threat. Applying good classifier with best feature selection achieved good result in terms of accuracy, 95%, and recognition rate, 93%. This study concluded that adopting best strategy in selecting features and classification yields better prediction in emergency case before medicating the patient even during treatment

Ride comfort optimization of a multi-axle heavy motorized wheel dump truck based on virtual and real prototype experiment integrated Kriging model

The optimization of hydro-pneumatic suspension parameters of a multi-axle heavy motorized wheel dump truck is carried out based on virtual and real prototype experiment integrated Kriging model in this article. The root mean square of vertical vibration acceleration, in the center of sprung mass, is assigned as the optimization objective. The constraints are the natural frequency, the working stroke, and the dynamic load of wheels. The suspension structure for the truck is the adjustable hydro-pneumatic suspension with ideal vehicle nonlinear characteristics, integrated with elastic and damping elements. Also, the hydraulic systems of two adjacent hydro-pneumatic suspension are interconnected. Considering the high complexity of the engineering model, a novel kind of meta-model called virtual and real prototype experiment integrated Kriging is proposed in this article. The interpolation principle and the construction of virtual and real prototype experiment integrated Kriging model were elucidated. Being different from traditional Kriging, virtual and real prototype experiment integrated Kriging combines the respective advantages of actual test and Computer Aided Engineering simulation. Based on the virtual and real prototype experiment integrated Kriging model, the optimization results, obtained by experimental verification, showed significant improvement in the ride comfort by 12.48% for front suspension and 11.79% for rear suspension. Compared with traditional Kriging, the optimization effect was improved by 3.05% and 3.38% respectively. Virtual and real prototype experiment integrated Kriging provides an effective way to approach the optimal solution for the optimization of high-complexity engineering problems

Research of VC Based Simulation Test System for Automotive ABS

A simulation test and analysis system for ABS control strategy was developed through the joint of VC++6.0 development platform and MATLAB/Simulink simulation platform. And the simulation test for ABS control strategy on four typical roads was carried out. Besides, the test results were analyzed. The test results showed that the system is able to give a good simulation of vehicles and roads and has the capacity of offering a good detection analysis. DOI: http://dx.doi.org/10.11591/telkomnika.v11i1.189

Longitudinal/Lateral Stability Analysis of Vehicle Motion in the Nonlinear Region

We focus on the study of motion stability of vehicle nonlinear dynamics. The dynamic model combining with Burckhardt tire model is firstly derived. By phase portrait method, the vehicle stability differences of three cases, front wheels steering/four-wheel steering case, front/rear/four-wheel braking case, and high/low road friction case, are characterized. With the Jacobian matrix, the stable equilibrium point is found and stable areas are calculated out. Similarly, the stability boundaries corresponding to different working conditions are also captured. With vehicle braking or accelerating in the steering process, the relationship between front/rear wheel slippage and the stable area is examined. Comparing with current literatures, the research method and its results present the novelty and provide a guideline for new vehicle controller design