Hybrid Suspension Research Articles

Hybrid Suspension Concept with a Driving State Adaptive Control Approach

Hybrid Suspension Concept with a Driving State Adaptive Control Approach

The Modeling of Needle for Hybrid Suspension Drive and Researching on Needle Motion Control

To the theory of jacquard knitting machine, this paper has proposed a new needle drive model of magnetic suspended needles. This model, based on hybrid suspension of electromagnets and permanent magnets theory, discussed needle model in the specific motion trail,through theoretical analysis and simulation of motion trail, revealed that realize the specific motion trail by maglev drive needle is available, and provide a new researching method of drive needle model for displace traditional knitting principle of mechanical multi-stage transmission. In theory, the model discussed the knitting principle of maglev drive needle in detail, and through the simulation and theory model of the trail, proved that the jacquard efficient is higher, and the structure is simpler and programmable. The electromagnetic and permanent model that the paper involved provide the basic theory for further discussing experimental program of drive needle, set relevant parameters.

1A2-F11 搭乗型移動支援ロボットの開発 : 広域自律移動のための姿勢安定化と地図生成(車輪型/クローラ型移動ロボット(2))

For the contribution to low-carbon traffic system in compact city, we are developing a human-riding robot for transportation support. In this paper, we introduce the hybrid suspension mechanism of the robot and the map generation method for wide-area autonomous navigation. The hybrid suspension mechanism with self-weight compensation keeps the postural stability of the robot in wide outdoor environments, and the generated wide-area map enables autonomous robot navigation. We report the result of the demonstration experiment in the robot special zone in Tsukuba-city, where the human-riding robot can run on the public road.

Study of EDS & EMS Hybrid Suspension System With Permanent-Magnet Halbach Array

In this paper, a permanent magnet (PM) electro-dynamic suspension and electro-magnetic suspension (EDS & EMS) hybrid suspension system is proposed to overcome the shortcomings of the under-damped dynamics in a PM EDS system. The linearized model is established and its stability is also analyzed using the Routh criterion. According to the rational distribution between the repulsive force and the electromagnetic force, a controller is designed to meet the dynamic performance required in practical applications. A novel maglev system using a hybrid suspension scheme is also presented in this paper. Furthermore, a single-degree-of-freedom (SDOF) hybrid suspension experimental mechanism is established, and some experiments have also been undertaken to validate its effectiveness on suppressing the oscillation of the PM EDS system caused by external disturbances.

Design of Hybrid Suspension System of Superconducting and Electrostatic Suspension

A new structure of superconducting suspension system is proposed based on a method used to calculate the magnetic field in a thin clearance between superconducting blocks. Force characteristic of the passive superconducting suspension system is analysed. Based on the existing structure of superconducting suspension system, an electrostatic suspension system is introduced to obtain high suspension stiffness. Details of the hybrid suspension system are introduced and the corresponding controller is also described. This paper provides a theoretical guidance for the next experiment, and also has reference to designing high stiffness suspension system.

Actively controlled vehicle suspension with energy regeneration capabilities

The paper presents an innovative dual purpose automotive suspension topology, combining for the first time the active damping qualities with mechanical vibrations power regeneration capabilities. The new configuration consists of a linear generator as an actuator, a power processing stage based on a gyrator operating under sliding mode control and dynamics controllers. The researched design is simple and energetically efficient, enables an accurate force–velocity suspension characteristic control as well as energy regeneration control, with no practical implementation constraints imposed over the theoretical design. Active damping is based on Skyhook suspension control scheme, which enables overcoming the passive damping tradeoff between high- and low-frequency performance, improving both body isolation and the tire's road grip. The system-level design includes configuration of three system operation modes: passive, semi–active or fully active damping, all using the same electro-mechanical infrastructure, and each focusing on different objective: dynamics improvement or power regeneration. Conclusively, the innovative hybrid suspension is theoretically researched, practically designed and analysed, and proven to be feasible as well as profitable in the aspects of power regeneration, vehicle dynamics improvement and human health risks reduction.

On laminar convective cooling performance of hybrid water-based suspensions of Al 2O 3 nanoparticles and MEPCM particles in a circular tube

Laminar forced convection of a hybrid water-based suspension of Al 2O 3 nanoparticles and microencapsulated phase change material (MEPCM) particles through a circular tube was investigated experimentally. In addition, an integral energy balance with scaling estimation is presented to elucidate influences of thermal properties of the hybrid suspension on its internal convection effectiveness. Experimental results show considerable enhancement in cooling effectiveness of the hybrid suspension over the pure PCM suspension, nanofluid, or water. However, the convection efficacy of utilizing the hybrid suspension appears severely outweighed by pressure drop penalty from its drastically increased viscosity with respect to the pure PCM suspension or the pure nanofluid.

Improving Suspension Control by an Optimal Control Component and Disturbance Compensation

AbstractThe paper presents an optimal control component to enhance the comfort achieveable by an existing reference model based controller. The basic controller concept controls a hybrid suspension system by emulating a timevarying damping and stiffness between wheel and chassis, resulting in significant improvements in comfort and safety compared to a passive suspension. It is extended by an optimal control strategy to increase its performance when passing single excitations critical for suspension deflection. The optimal control component uses offline calculated optimal control solutions for the actual vehicle states to react at an early stage of the compression movement leading to a smoother and lower chassis acceleration when passing critical excitations. The presented additional disturbance compensation uses information about the road excitation to beneficially influence the wheel movement. The feedforward filter influences the wheel dynamics such that a significant reduction of wheel load deviations is reached while additionally reducing chassis acceleration.

Design Concepts and Principle of Operation of the HeartWare Ventricular Assist System

Implantable left ventricular assist devices provide circulatory support for patients at risk of death from refractory, end-stage heart failure. Rotary blood pumps have been designed for increased reliability and smaller size for use in a broader population of patients than the first-generation pulsatile devices. The design concepts and principle of operation of the HeartWare System are discussed. The HeartWare Ventricular Assist System (HVAD) is a small centrifugal flow pump with a displacement volume of 50 ml and an output capacity of 10 L/min. A unique wide-blade impeller is suspended by hybrid passive magnets and hydrodynamic forces. An integrated inflow cannula is inserted into the left ventricle and is held in position by an adjustable sewing ring; the pump is positioned in the pericardial space. The 10-mm outflow graft is anastomosed to the ascending aorta. External system components include the microprocessor-based controller, a monitor, lithium-ion battery packs, alternating current and direct current power adapters, and a battery charger. Physiologic control algorithms are incorporated for safe operation. Preclinical life cycle tests have shown the HVAD to be highly reliable. This system design offers reliability, portability, and ease of use for ambulatory patients.

Reference model based adaptive control of a hybrid suspension system

The paper presents a new adaptive controller structure for a hybrid quarter-vehicle suspension system containing a low bandwidth actuator and a semi-active damper. The optimal control force to ease the conflict between ride comfort, ride safety and limited suspension deflection is obtained from a reference model based on a passive suspension system with timevarying stiffness and damping. By allocating the resulting control force to the two actuators, the power demand of the hybrid suspension system is significantly lower compared to a high bandwidth active system although their performance is similar. Stability of the adaptive controller structure is guaranteed using a Lyapunov function approach. The hybrid suspension is compared with benchmark systems in simulations under realistic assumptions regarding nonlinearities of the suspension elements, the actuator and sensor architecture as well as the road profile.

Hybrid multiwalled carbon nanotubes and trioxide tungsten nanoparticles for hydrogen gas sensing

The WO3/multiwalled carbon nanotubes (MWNTs) hybrid films were fabricated by spin-coating on an alumina substrate. The structure, morphology, chemical composition and quality of the as-prepared WO3 nanoparticles, functionalized MWNTs and WO3/MWNTs hybrid films were studied by SEM, TEM, XRD, XPS, DLS and Raman spectroscopy methods. Results show that WO3 nanoparticles were nucleated on oxygenated functionalized MWNTs in hybrid suspension. After coating and annealing the films at 350 °C, the hybrid WO3/MWNTs films present rather linear gas sensitivity as a function of hydrogen concentrations at 300 °C. Results are discussed based on surface increase as well as development of two types of Schottky potential barrier height, one at the n-WO3/p-MWNTs hetero-junction and the other at WO3 grain boundaries.

Spin coating of hybrid suspensions using infrared-irradiation to increase layer thickness

This paper describes an increase in thickness of spin coated layers by using IR-irradiation. Hybrid suspensions with 5 wt.% solid content (80% BaTiO 3, 20% ZrO 2) are spin coated on platinized silicon wafers. The IR-irradiation increases the evaporation rate and accelerates the aging of the solution. This leads to an increase in viscosity and a faster increase of the solid content, which results in an earlier percolation of the hybrid suspension with more particles remaining on the substrate. Using IR-irradiation, an increase in layer thickness from 71 nm to 242 nm could be achieved in one coating step.

An organic matrix-mediated processing methodology to fabricate hydroxyapatite based nanostructured biocomposites

An amorphous calcium phosphate precursor phase, which forms by adding orthophosphoric acid to a calcium hydroxide suspension, is transformed into crystalline hydroxyapatite by introducing polymer solutions. The nanostructured composite films formed by a solvent casting technique from the concentrated hybrid suspension are characterised for structure and mechanical properties.

Investigation on mechanics performance of cable-stayed-suspension hybrid bridges

The cable-stayed-suspension hybrid bridge is a cooperative system of the cable-stayed bridge and suspension bridge, and takes some advantages and also makes up some deficiencies of both the two bridge systems, and therefore becomes strong in spanning. By taking the cable-stayed-suspension hybrid bridge, suspension bridge and cable-stayed bridge with main span of 1400 m as examples, the mechanics performance including the static and dynamic characteristics, the aerostatic and aerodynamic stability etc is investigated by 3D nonlinear analysis. The results show that as compared to the suspension bridge and cable-stayed bridge, the cable-stayed-suspension hybrid bridge has greater structural stiffness, less internal forces and better wind stability, and is favorable to be used in super long-span bridges.

Rheology of a Polymer‐Based Hybrid Suspension Composed of Concentrated Poly[(D,L‐lactide)‐co‐glycolide] Solution and Inorganic Salt Particles

Suspensions composed of a solution of a biodegradable polyester in a volatile organic solvent, and solid inorganic particles of size in the order of hundreds of microns have been very important in the fabrication of porous scaffolds in the field of tissue engineering. This article reports the basic rheological investigations of this complex fluid type. A Couette geometry covered by silicon oil was found to be an appropriate geometry to retain stability of the rheological measurements. Suspension viscosity increased with the particle volume fraction, and the extent of the increase was much larger than that predicted by the Einstein suspension equation. Both start-up dynamics at the inception of steady shear and relaxation after an abrupt change of oscillatory shear frequency in the suspension showed significantly different behaviors from those in the associated polymer solution. Particle reorganization upon change of rheological state was anticipated.

Synthesis and Electrorheological Characterization of Polyaniline/Barium Titanate Hybrid Suspension

AbstractAs organic/inorganic composites having attracted much attention due to their heterogeneous physical properties, conducting polyaniline (PANI) and barium titanate (BaTiO3) which possesses large electronic resistance and excellent dielectric strength, were utilized to synthesize PANI/BaTiO3 hybrid which is applicable for an electrorheological (ER) material via ‘in‐situ’ oxidative polymerization. Physical properties of the obtained PANI/BaTiO3 composites were characterized via Fourier‐transform infrared spectra (FT‐IR), thermogravimetry analysis (TGA), and scanning electron microscopy (SEM). The ER behaviors were investigated via a rotational rheometer, and their shear stresses were fitted using our previously proposed rheological equation of state.

Poly(vinyl alcohol)–hydroxyapatite biomimetic scaffold for tissue regeneration

Hydroxyapatite–poly(vinyl alcohol) composite blocks were produced by freeze–thawing in situ synthesized hybrid suspension. Matrix mediated precipitation of hydroxyapatite particles in the polymer, controlled the particle size in nanometer range (< 100 nm) and hydrogelation induced an ordered three-dimensional assembly of the particles. Morphological and crystallographic characterization revealed the formation of a macro-porous hydroxyapatite–poly(vinyl alcohol) nanocomposite block. Initial results indicate compositional dependence of modulus of elasticity of the composite.

Synthesis and electrorheological characteristics of polyaniline-titanium dioxide hybrid suspension

Conducting polyaniline (PANI)/titanium dioxide (TiO 2) hybrid particles were synthesized via an oxidation polymerization in the presence of TiO 2, and their electrorheological (ER) characteristics were examined, since the formation of an organic/inorganic hybrid exhibits various advantages from the combination of their unique properties as a part of our efforts to find highly potential ER-active particles using conducting polymers. The TiO 2 nanoparticles possess a relatively high dielectric constant which is important for polarization in the ER response, in which the ER fluids are a class of colloidal suspensions which show a transition from a liquid-like to a solid-like state under an applied electric field. Synthesized PANI/TiO 2 composites in this study were characterized by an FT-IR, thermogravimetry analysis, and scanning electron microscopy. We then prepared the PANI/TiO 2 composites-based ER suspension with insulating oil and investigated its ER behavior as a function of shear rate under an applied electric field. The fast relaxation time of PANI/TiO 2 hybrid was expected to enhance electrostatic force over shear force under a shear flow, showing the improved ER performance. Furthermore, it was also found that the properties of TiO 2 affect the dielectric of PANI/TiO 2 composites to give better ER properties.

The removal and photodecomposition of n-nonylphenol using hydrophobic clay incorporated with copper-phthalocyanine in aqueous media

In order to achieve the effective removal and decomposition of n-nonylphenol (Np), an endocrine disruption chemical with poor solubility, tenuously dispersed in environmental water, the synthesis and characterization of a hydrophobic clay (HpC) with copper-phthalocyanine (CuPC) were investigated. The HpC powders were prepared by intercalating the cetyltrimethylammonium cations (CTA +) into montmorillonite (Mont) interlayers. The HpC compound incorporated with CTA + molecules and equal to the cation-exchangeable capacity (CEC) of Mont were found to adsorb almost completely the Np molecules from the aqueous solution by the hydrophobic interaction between the alkyl chains of the CTA + and Np molecules. The CuPC molecules were incorporated with the HpC compound in order to add the photodecomposition properties of CuPC to the HpC compound. This HpC/CuPC hybrid efficiently adsorbed the Np molecules from the polluted water, too. Visible-light irradiation of the Np aqueous HpC/CuPC hybrid suspension under O 2 atmosphere at 620 nm decomposed the Np molecules having been adsorbed at the hydrophobic spaces of the HpC/CuPC hybrid materials, forming quinonmethane molecules by the singlet oxygen produced by the photosensitization reaction of the cointercalated CuPC molecules.

A neural network approach to the design of a vehicle's non-linear hybrid suspension system

In the following, a design method is presented for non-linear hybrid suspension systems of vehicles based on neural networks. A hybrid suspension system is one that behaves as an active suspension system only when the road excitation amplitude is above a prescribed value. Discontinuous operation of the controller helps to minimize the energy consumed by the actuator. The design targets of our method are the minimization of the vertical acceleration imposed on the passengers as well as the respect of all the design and construction constraints. The neural network used is obtained by a Taylor approximation of the unknown non-linear control function. Because of the existence of numerous local minima of the neural network, an evolutionary algorithm is used to solve the resulting neural network problem.