Suspension Assembly Research Articles

Crosstalk Reduction on 6-line Suspension Assembly Interconnect Trace in Head Gimbal Assembly by using Guard Technique

The guard technique is proposed by adding the stainless steel at backing layer to reduce the crosstalk on 6 lines suspension assembly interconnect trace (SAIT). The Near-End and Far- End crosstalk coefficients (NEXT and FEXT) are used to analyze the crosstalk on the SAIT in the frequency of 0-20GHz. The finite integration technique (FIT) is used in the simulation based on CST microwave studio. The space between heat and read pairs is modified and guard addition at the space is also varied. From the results, it is found that the varying of space cannot reduce the crosstalk. However, the additional guard can reduce the crosstalk by monitoring the NEXT and FEXT. The lowest crosstalk is at 100% of the space with 100% of guard that can attenuate the noise around 4.7 and 3.2dB for NEXT and FEXT, respectively. The 80% of space with 80% of additional guard has the crosstalk less than or equal to the conventional SAIT. In addition, it can also decrease the dimension of SAIT about 11.87% of the conventional SAIT. Hence, this technique can reduce the crosstalk and can decrease the dimension of the SAIT which is useful for the robustness for future SAIT design.

Windowing and Groove Depth Variation Techniques for Crosstalk Reduction on Six-Line Suspension Assembly Interconnect Trace in Magnetic Recording Heads

Windowing and Groove Depth Variation Techniques for Crosstalk Reduction on Six-Line Suspension Assembly Interconnect Trace in Magnetic Recording Heads

The Discussion of the Simulation Accuracy of the Vehicle Suspension Coupled Dynamics Model

Take a vehicle front suspension assembly as an example, established the dynamics model of vehicle front suspension. Compared different results of dynamics models with the opposite travel test. Proved the effect of flexible body in the vehicle suspension dynamics model. Provided a reference method for the establishment of vehicle suspension dynamics model.

Optimization of Double Pivot Suspension Kingpin Axis during Steering

A double pivot suspension used for in-wheel motor electric vehicle was designed, and the virtual prototype model of the suspension assembly was build. The suspension parameters changed greatly during steering. In order to solve this problem, this paper proposed a non-linear response surface model to fit the relationship of suspension parameters and design variables. An optimization scheme was designed based on the response surface model. The suspension performance was improved significantly using optimized variables.

Formula SAE Racecar Suspension System Design

For racing application, what actually counts is the wheel path during bump and the consequently change of wheel parameters like camber. The suspension system mainly comprises of the elastic components (springs), shock absorbers and control arms. This paper covers: Firstly, the selection of the suspension type of a FSAE racecar. Secondly, how to determine the hard points of the suspension system according to the general envelop of the racecar. Then the 3D-modeling and assembly of the suspension system will be done using Autodesk Inventor; With the results from the kinetic and dynamics simulations using ADAMS, adjustments or amendments will be done to the system to optimize the change of parameters in bump and roll; At last, according to the results of the FEA processes, the structure of the control arms, uprights, rockers, etc. will be optimized so that the stress of each components within strength limitations. Finally, optimize the suspension assembly and make sure it meets the practical requirements.

Performance analysis of an integrated piezoelectric ZnO sensor for detection of head–disk contact

Integrated capability for detection of head–disk contact is desired for magnetic sliders with near-contact flying height. At the same time, fabrication of added features should be compatible with the existing slider micromachining process which is highly specialized and cost sensitive. Aimed at meeting the two requirements, a novel sensor configuration is explored in the present study. The new sensor configuration consists of a piezoelectric zinc oxide (ZnO) thin-film sensor sandwiched in the magnetic slider on its trailing side. Coupled structural and piezoelectric finite-element analysis for a sensor–slider–suspension assembly was performed to investigate the dynamic sensing performance. Output voltages on the millivolt level were obtained under typical head–disk interactions. The second in-plane bending mode of the slider was found to be the major contributor to the output voltage. Parametric study further showed that a thicker ZnO layer generally generated a larger output, while the thickness of the slider overcoat had only minimal effect. Simulation results from harmonic and transient analyses demonstrated that the piezoelectric thin-film ZnO sensor was sufficiently sensitive for detection of head–disk contact.

Design and positional accuracy of straight-path traversing room acoustic measurement system based upon low-cost servo motor and light-weight multi-field microphone

The construction and operation of a straight-path traversing, acoustical microphone-based, measurement system is described. The system was designed to support test room qualification procedures such as prescribed in standards ANSI S12.35-1990 and Annex A of ISO 3745-2003. Major system components include a taut line suspending a sliding microphone carriage drawn by a string attached to a rotating drum. Central to the overall light-weight, low-power, mechanical design is the physically small Bruel & Kjaer 4961 microphone, holder, preamp, and signal cable whose multi-field response characteristic should well support accurate room qualification measurements. The battery-powered drum drive mechanism is built using the servo motor, wheels, and gears from a Lego Mindstorms NXT kit. Precision motor rotation is remotely programmable over the NXT controller’s wireless Bluetooth interface. Commonly available sport fishing tackle composes the majority of the suspension assembly. A software interface library is also d...

Study on Influence Analysis of Vehicle Steering Gains Based on ADAMS/Car of Suspension Torsion Bar and Anti-Roll Bar

In order to study the effect of stiffness of the suspension and anti-roll bar on the vehicle handling performance, and provide reference for suspension design and adjustment afterwards, two virtual prototypes and their variants without anti-roll bar and front suspension assembly anti-roll bar, were structured in ADAMS/Car. Through simulation test with input of steering wheel angle step, the curves of effect of angle stiffness of front suspension torsion bar and anti-roll bar on vehicle steering gain were obtained. On two models, steering gains respectively produced about 20% and 1% decline of the range of experience while the angle stiffness of torsion bar increased from 0.5 to 2.0 times of the base stiffness; steering gain respectively produced about 10% increase or 1% decline of the range of experience while the angle stiffness of anti-roll bar decreased from the base angle stiffness to 0 or increased to 2.0 times of the base stiffness.

Active Vibration Control of a Microactuator for the Hard Disk Drive Using Self-Sensing Actuation

This paper presents the self-sensing control of a microactuator for hard disk drives. The microactuator uses a PZT actuator pair installed on the suspension assembly. The self-sensing microactuator forms a combined sensing and actuation mechanism. Direct velocity feedback and positive position feedback are used in this paper. Our experimental results show that both strategies are effective in suppressing vibrational modes and successfully demonstrate the feasibility of using a self-sensing actuator on an HDD suspension assembly.

Enhancement of PZT embedded swing arm actuator using integrated read/write performance and actuation

The current technological challenges associated with the rotary-type seesaw arm actuator for small-form-factor (SFF) disk drives are the small skew focusing, which causes off-axis aberrations and reduces optical quality. This article develops a novel design for a seesaw arm actuator and suspension assembly that is based on a micro-PZT actuator to position pickup head. Dual-stage actuation relaxes the dynamic requirement on the focusing stroke. The proposed actuator with a tilt-compensation mechanism uses a PZT bender to drive pickup head focusing. This combined system, optical module and dual stage actuator, is effectively self-aligned the optical axis for read/write performance in both experiment and simulation result. Finite element modeling and dynamic measurements reveal significant improvements in the actuator bandwidth with and without micro-PZT actuator compensation.

Design and development of the advanced LIGO monolithic fused silica suspension

The detection of gravitational waves remains one of the most challenging prospects faced by experimental physicists. One of the most significant limits to the sensitivity of current, and future, long-baseline interferometric gravitational wave detectors is thermal displacement noise of the test masses and their suspensions. Suspension thermal noise will be an important noise source at operating frequencies between approximately 10 and 30 Hz, and it results from a combination of thermoelastic damping, surface loss and bulk loss associated with the suspension fibres, and weld loss from their attachment. Its effects can be reduced by minimizing thermoelastic loss and optimizing pendulum dilution factor via the appropriate choice of geometry of the suspension fibre and attachment geometry. This paper will discuss the design and fabrication of a prototype of the fused silica suspension stage for use in the advanced LIGO (aLIGO) detector network, analysing in detail the design of the fused silica attachment pieces (ears), together with the suspension assembly techniques. We also present a full thermal noise analysis of the prototype suspension, taking into account for the first time the precise shape of the actual fibres used, and weld loss. We shall demonstrate the suitability of this suspension for installation into aLIGO.

체압 분포를 고려한 자동차 시트용 플라스틱 서스펜션에 대한 기초적 연구

본 연구는 자동차용 시트 Back frame 내부에 설치하여 탑승자의 등부분을 지지하며 편안한 승차감을 제공하는 시트용 서스펜션 시스템에 대한 연구이다. 운전자의 등 전체를 고르게 지지하는 구조로 설계하고 시트 백 프레임과 플라스틱 서스펜션의 조립을 효과적으로 할 수 있는 구조로 개발 하고자 한다. 서스펜션 단품은 운전자의 체압 분포를 고려하여 설계하고 시뮬레이션 해석에 있어서는 실제 모델과 같은 크기를 가지고 하였다. 플라스틱 서스펜션의 해석결과가 실제 측정값에 근접함을 확인하였으며 기존 Wire Type에 비해 양호한 체압분포를 얻을 수 있었다. This study investigates the plastic suspension assembly which is installed on inside of vehicle seat and support passenger's back to supply the comfortable ride performance. It aims to develop the structural design in order to support driver's back uniformly and assemble seat back frame with plastic suspension effectively. The part of suspension is designed by considering the body pressure distribution of driver and it has the same size as the practical model on simulation analysis. It is confirmed that the analysis result of plastic suspension approaches the practical measured values and the better body pressure distribution can be obtained as compared with the existing wire type.

A Practical Crosstalk Reduction Technique Applied to High-Density Hard Disk Interconnecting Assembly Traces

A novel electromagnetic (EM) decoupling and crosstalk reduction technique applied to hard disk drive is presented. Grooves are introduced with different depths between conductors of the trace suspension assembly interconnects (TSAI). By using commercial EM simulation software, an induced voltage from an unwanted external field on TSAI is reduced in relation with groove depth. As much as 12.5-dB decoupling is observed for 25%-75% groove depths. The crosstalk reduction obtained over 1.0 dB for 1-4 GHz frequency band is achieved and the transmission bandwidth has increased by 20% at 75% groove depth. Hence, additional grooves will strengthen the immunity of TSAI at the reader sensor against external field disturbances as well as offer an improved transmission performance.

Neural network based control of a suspension assembly with self-sensing micro-actuator for dual-stage HDD

This paper presents a system identification process and control system design of an artificial neural network based suspension assembly with self-sensing micro-actuator for hard disk drives. Artificial neural networks can be used effectively for the identification and control of nonline ar dynamical systems such as flexible micro-actuators and self-sensing systems. Three neural networks are developed for the self-sensing micro-actuator. The first for system identification, the second for inverse modeling for control using the signal from a laser sensor, and the third for inverse modeling for control using the signal from a self-sensing piezoelectric. We also use a neural network inverse model to control the suspension assembly which includes a micro-actuator pair. Simulation and experimental results show that good control performance can be achieved using artificial neural networks.

Tools and equipment modelling for interactive assembling operating in a virtual environment

Tools and equipment (T&E) play an important role in the simulation of virtual assembly, especially in the assembly process simulation and plan. The interactive operation simulation of T&E is also a challenge for interactive assembly operation because of variety in function and complexity in structure and manipulation. Based on detailed analysis of interactive operations, the functional requirement for T&E is given. Then, a unified modelling method for information expression and function realisation of general T&E is represented, and the handling methods of some typical manual, semi-automatic, automatic T&E are discussed. Finally, the rear suspension and the front suspension assembly workplace operation simulation in the RA-750 car assembly line are introduced. The result shows that the modelling and handling methods are applicable in the interactive simulation of various T&E.

자동차 시트용 플라스틱 서스펜션 시스템 개발

This study aims to develop the plastic suspension assembly which is installed on inside of vehicle seat and supports passenger`s back to provide the comfortable feeling. This design is the suspension structure to support the back equally and assemble seat back frame and plastic suspension effectively. The parts of suspension are designed by considering the property of body pressure distribution. As analysis values are approached to measured values by comparing the deformations in the cases of existed spring suspension and developed plastic suspension, the optimum design can be established.

Constrained Response Surface Optimization for a Laser Beam Welding Process

Problem statement: On a current operating condition of a laser beam welding process in the hard disk drive industry, it has been found that shear strength of the head support and suspension assembly is slightly higher than customers' specification. This situation leads to an inspection with a large sample size and a high frequency. Shear strength is not only one quality characteristic for this assembly, but other critical physical specifications of welding diameter and depth need to be also considered. Approach: A hybridization strategy, based on linear and nonlinear Constrained Response Surface Optimization Methods (CRSOM), has been developed for this process refinement. The hybridization is having a provision to include both explicit constraints of influential process variables as well as implicit constraints of physical specifications. Results: The proposed levels of influential process variables have been successfully implemented in terms of shear strength and satisfied both welding diameter and depth specifications. Conclusion: The advantage of the hybridization compared with individually CRSOM is that all the data from the experiment is collected together to make a final decision. When engineering problems are large and complicated, an effective finite sequence of instructions from the hybridization can be very useful and practical in setting industrial processes such as semiconductor or automotive manufacturing systems.

Efficient simulation of hard disk drive operational shock response using model order reduction

The complex structure, coupled mechanical and fluidic energy domains, and inherent nonlinearity of air bearing between slider and disk involved in the hard disk drive (HDD) are normally presented as a large scale problem which will result in very heavy computational costs in terms of intensive computation and time consuming for HDD research communities and industries to carry out the transient dynamic simulation for HDD design verification, performance analysis, and optimization by using the traditional full-order models, such as finite element model (FEM). This paper presents a method of application of model order reduction (MOR) technique to dramatically reduce the computation time for HDD transient shock performance analysis while capturing the behaviors of original problem faithfully. The reduced models are obtained by performing MOR directly to the FEMs through Krylov subspace and Arnoldi algorithm. The transient operational shock response results of the reduced models of a head suspension assembly (HSA) subjected to half-sine shock pulse demonstrate that the reduced models can dramatically reduce total computation by at least three orders and have very good agreement with those simulated from the original large problem by full-order FEM.

후륜 현가장치용 CTBA 튜브 프레스 성형공정 개발

Process design is carried out for a press forming of a CTBA in the rear suspension assembly based on the result of the finite element analysis. The analysis simulates the two-stage stamping process with the initial design and it fully reveals the unfavorable mechanism which develops inferiorities during forming. In this paper, a new design guideline is proposed to modify the process and tool shapes for a single-stage forming process. With the improved tool design, prototypes are fabricated after several try-out processes. Results of the durability tests show that the design requirement of the part is satisfied and the effective weight reduction is achieved.

Tool design for the tubular press forming of a rear suspension member with the finite element analysis

Tool design is carried out for a press forming of a tubular axle in the rear suspension assembly based on the result of the finite element analysis. The analysis incorporates a three-dimensional elasto-plastic finite element method with the explicit time integration scheme by using LS-DYNA3D. The analysis simulates the two-stage stamping process and it fully evaluates the deformation mechanism by forming and springback. With the trial tool shape, simulation is performed in order to investigate failure by wrinkling, shape inaccuracy and the local deformation. This paper identifies such unfavourable mechanism in the tubular press forming and proposes a new tool design with a guideline for modification in the design of the process and sequential tool shapes. The finite element analysis result with the improved tool design confirms that the proposed design not only reduces the possibility of failure, but also improves the quality of a formed product.