Design of suspension and swing arm for improved shock resistance in the micro optical disk drives

One of the trends on information storage device is focused on the development of micro optical disk with optical flying head (OFH). The OFH in the small form factor ODD consists of optical slider, suspension, swing arm, and so on. In order for a slider with OFH to be successfully implemented in the system, the shock performance of the head-gimbal assembly should be guaranteed for mobile applications. We design development model of suspension and swing arm for improved shock resistance using topology optimization and shape optimization. The objective of the suspension design is to decrease the equivalent mass with increasing first torsional frequency. The objective of the swing arm design is mass reduction for reducing power consumption and fast access time. In this paper, we suggest a design method for the improvement of the dynamic performance of suspension and swing arm for the OFH considering shock characteristics.     

星载光谱仪摆臂系统的变结构空间抗扰控制

针对高精密星载光谱仪摆臂系统的空间微重力、微振动抗扰问题,提出一种积分滑模变结构控制策略．首先给出了空间微重力、微振动对摆臂系统的干扰模型;然后,根据系统对光程差速度的控制要求以及与电机角速度的非线性关系,给出了积分滑模变结构控制的设计方法;最后,将所提出的控制方法与PI调节控制进行抗干扰对比仿真,所得结果表明,该方法能有效抑制空间微重力、微振动等引起的扰动,保证系统的鲁棒性．     

Development of an optical flying head for a next-generation magneto-optical recording system

We have developed an optical flying head (OFH) comprising a thin-film coil and a high numerical aperture lens for magneto-optical (MO) disk drives. Experiments have shown successful writing and reading of MO media. The following describes the design and testing of the OFH.     

A swing arm actuator for a small form factor optical drive

Small form factor optical drives for mobile application require high performance actuators that satisfy tight geometrical size requirements. We have designed a swing arm type actuator that allows the integration of a complete miniaturized optical pickup unit on the actuator. The performance of the actuator has been simulated by the FEM method and is compared with experimental results. Finally the manufactured actuator was used to read out a Blu-ray ROM disc.     

Design of swing arm actuator for small and slim optical disc drives

Recent advancements in mobile devices have fueled a requirement for information storage systems with characteristics such as subminiature size, low cost, and minimum power consumption. Small optical disk drives could provide a good solution, because their storage media is cheaper than those of hard disk drives or flash memories. In this paper, we proposed the miniaturized swing arm type actuator that had a new focusing mechanism for small and slim optical disk drives (ODD). Initial model was designed by EM and structural analyses. Based on results of DOE, optimization procedures of EM circuits were performed with design variables using variable metric method (VMM). And, structural parts were designed to maintain the high sensitivity of the actuator. Finally, the swing arm type actuator for small and slim ODDs was suggested and its dynamic characteristics were checked.     

基于虚拟样机技术的某型摆臂机构研究

摆臂机构是舰炮发射系统的重要组成部分。某型舰炮摆臂机构采用电机作为外能源,带动齿轮齿条直线运动,进而通过连杆机构带动摆臂实现摆动。上述摆臂机构由多种动力传递和转换组成,采用传统设计方法进行论证研究成本高,难度大。为验证摆臂机构可行性以及机构运动可靠性,同时为摆臂机构电机设计提供依据,结合多刚体系统动力学理论,运用MTALAB和ADAMS软件对摆臂机构进行联合仿真计算,通过动力学仿真,分析齿轮齿条的受力情况,为摆臂结构优化和电机动力设计提供参考。     

Design of swing arm type actuators considering thermal and dynamic characteristics

The present state of the design of swing arm actuators for optical disc drives is to obtain the highly efficient dynamic characteristics within a very compact volume. As a necessary consequence, the need of the small form factor (SFF) storage device has arisen as a major interest in the information storage technology. Due to the size constraint, the thermal stability of the optical pick-up head is important: therefore, the actuator is designed to emit the heat, which is generated by the optical pick-up, along the structural body easily. In this paper, we suggest the miniaturized swing arm type actuator that has effective heat emission quality as well as satisfies the dynamic requirements for the SFF optical disk drive (ODD). The actuator is targeted to be installed in CF-II card size drive to be competitive with flash memory or mini hard disk drive used in mobile electric devices; therefore the dimension of the actuator is required as 11.0 mm × 2.5 mm × 25.0 mm (width × height × length). Because of its small size, the dynamic requirements are severe to ensure the enough gain-margin for the system control together with satisfying the DC/AC sensitivity conditions. Moreover, due to the small size, the maximum pick-up temperature is critical in design because the system has high possibility to reach the shut-down temperature. For the operating mechanism, it uses a tracking electromagnetic (EM) circuit for the focusing motion together and the initial model is designed and promoted by the design of experiments (DOE) only considering the dynamic characteristics. New concept design is suggested based on the topology optimization method considering the thermal conductivity. Furthermore, the new design is modified by DOE to maintain the high sensitivity and to have wide control bandwidth and decreasing mass and inertia. The final design of a swing arm type actuator for SFF ODD is suggested and its dynamic characteristics are verified.     

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.     

Selection of two arm-swing strategies for bipedal walking to enhance both stability and efficiency

Walking ability, which involves mainly stability and efficiency, is one of the most important issues in humanoid robots. Effective use of a robot’s arms is expected to improve its walking ability under its body constraints. Although several types of arm-swing strategies have been proposed, they are difficult to execute simultaneously. We propose two-stage integration of these strategies to enhance both stability and efficiency. A selection algorithm for locomotion (SAL) selects the appropriate strategy according to the demands of the situation. In the first stage, two strategies are evaluated. One of them, Ro-SAL, entails use and compensation of the moment of the swing leg by hip rotation and arm swing. The other strategy, Su-SAL, entails the support of center of gravity trajectory tracking based on a predictive control. Ro-SAL is effective for the stable state and states with internal model error, whereas Su-SAL is effective in states with external force and environmental complexity. In the second stage of the proposed method (AS-SAL), the robot recognizes the current state and selects the optimal combination of the two arm-swing strategies. As a result, a humanoid robot can exhibit more efficient, stable bipedal walking without falling.     

A study on a brachiation controller for a multi-locomotion robot — realization of smooth,continuous brachiation

In this paper, we present a control method to realize smooth continuous brachiation. The target brachiation is basically divided into two actions: a swing action and a locomotion action. In order to realize the continuous brachiation effectively and smoothly, it is necessary to start the swing action as soon as the robot grasps the front target bar at the end of the locomotion action. The collision, which occurs at the moment the robot grips the target bar, affects the pendulum motion of the robot. The action of bending the elbow joint of the swinging arm is proposed in order to solve this gripping problem. The elbow-bending action enables the robot to decrease the impact forces and use the excess mechanical energy after the end of the locomotion phase. Thus, there is no loss of energy and waste of time during the subsequent swing phase. Experimental results show that the robot can successfully achieve smooth, continuous brachiation.     

随动定位式医用扶持机器人系统研制

电极针是超声引导下肝肿瘤微波消融微创手术的关键器械。针对医生在扶持操作中手部的抖动或用力的不均匀而造成的电极针偏移问题,研制了一种随动定位式扶持电极针的机器人,通过手术医生拉动把手带动机械臂摆动,仿生机械手移到电极针上方并锁紧定位;通过传感器筒体内的遮光片和对应光耦的相对位置变化来感知电极针的偏转及直线运动,控制摆动和伸缩电机转动,从而实现随动扶持。临床实验表明,该机器人系统大大减少了手术中的人为因素,使微创治疗更为精确、灵巧与安全。     

Topology design to improve HDD suspension dynamic characteristics

In this paper, topology optimization in design of suspensions for high-density magnetic recording systems is studied. With the development of higher data density and the faster data streaming, a hard-disk drive (HDD) is required to move faster with greater positioning accuracy. At this situation, even small mechanical vibration induced by seeking motion may result in error in data reading. According to the operational characteristics of HDD suspension, the present work is focused on the topology design of HDD suspension for the dynamic shock response problem. As a result of this research, several new topological structures of HDD suspension are obtained, which are largely different from previous work, and dynamic response under shock force and stability of passive structure are also improved.     

Minimum weight design of solid annular plates under an assigned limit ring load

In this paper, topology optimization in design of suspensions for high-density magnetic recording systems is studied. With the development of higher data density and the faster data streaming, a hard-disk drive (HDD) is required to move faster with greater positioning accuracy. At this situation, even small mechanical vibration induced by seeking motion may result in error in data reading. According to the operational characteristics of HDD suspension, the present work is focused on the topology design of HDD suspension for the dynamic shock response problem. As a result of this research, several new topological structures of HDD suspension are obtained, which are largely different from previous work, and dynamic response under shock force and stability of passive structure are also improved.     

掘进机截割臂摆速自动控制方法研究

由于掘进巷道煤岩时有硬度急剧变化现象,人工操控难以及时有效改变掘进机截割臂摆速,会严重影响截割头截齿与截割电动机的使用寿命。针对该问题,在分析截割臂摆速v、截割电动机电流I和煤岩硬度f之间的关系的基础上,提出了基于PID技术的截割臂摆速自动控制方法,即将截割电动机额定电流与实际电流之差值(I0-I)作为输入变量,通过比例单元、积分单元和微分单元的线性组合,对控制电液比例阀阀口开度的电流I1进行控制,从而控制截割臂摆速;依据煤炭行业标准MT/T971—2005,提出了5%的控制精度标准。该控制方法达到了替代人工操控、有效保护截齿和截割电动机,并同时使得截割电动机始终满载恒功率工作的目的。     

基于拓扑优化的新能源汽车摆臂轻量化设计

为对某新能源车型前悬挂下摆臂进行结构轻量化设计,运用悬挂动力学模型提取摆臂各连接点在各工况下的静载荷,结合拓扑优化分析方法,获得摆臂的最佳传力路径和材料分布,明确轻量化优化方向。优化结果表明,优化后的摆臂强度满足设计要求,质量减小27%。     

Design,fabrication, and testing of a 3-DOF HARM micromanipulator on (1 1 1) silicon substrate

In this study, a novel HARM (high aspect ratio micromachining) micromanipulator fabricated on (1 1 1) silicon wafer is reported. The micromanipulator consists of a positioning stage, a robot arm, supporting platforms, conducting wires, and bonding pads. These components are monolithically integrated on a chip through the presented processes. The three-degrees-of-freedom (3-DOF) positioning of the micromanipulator is realized by using the integration of two linear comb actuators and a vertical comb actuator. The robot arm is used to manipulate samples with dimension in the order of several microns to several hundred microns, for instance, optical fibers and biological samples. The robot arm could be a gripper, a needle, a probe, or even a pipette. Since the micromanipulator is made of single crystal silicon, it has superior mechanical properties. A micro gripper has also been successfully designed and fabricated.     

The influence of rifle carriage on the kinetics of human gait

The influence that rifle carriage has on human gait has received little attention in the published literature. Rifle carriage has two main effects, to add load to the anterior of the body and to restrict natural arm swing patterns. Kinetic data were collected from 15 male participants, with 10 trials in each of four experimental conditions. The conditions were: walking without a load (used as a control condition); carrying a lightweight rifle simulator, which restricted arm movements but applied no additional load; wearing a 4.4 kg diving belt, which allowed arms to move freely; carrying a weighted (4.4 kg) replica SA80 rifle. Walking speed was fixed at 1.5 m/s (±5%) and data were sampled at 400 Hz. Results showed that rifle carriage significantly alters the ground reaction forces produced during walking, the most important effects being an increase in the impact peak and mediolateral forces. This study suggests that these effects are due to the increased range of motion of the body's centre of mass caused by the impeding of natural arm swing patterns. The subsequent effect on the potential development of injuries in rifle carriers is unknown.     

The influence of rifle carriage on the kinetics of human gait

The influence that rifle carriage has on human gait has received little attention in the published literature. Rifle carriage has two main effects, to add load to the anterior of the body and to restrict natural arm swing patterns. Kinetic data were collected from 15 male participants, with 10 trials in each of four experimental conditions. The conditions were: walking without a load (used as a control condition); carrying a lightweight rifle simulator, which restricted arm movements but applied no additional load; wearing a 4.4 kg diving belt, which allowed arms to move freely; carrying a weighted (4.4 kg) replica SA80 rifle. Walking speed was fixed at 1.5 m/s (+/-5%) and data were sampled at 400 Hz. Results showed that rifle carriage significantly alters the ground reaction forces produced during walking, the most important effects being an increase in the impact peak and mediolateral forces. This study suggests that these effects are due to the increased range of motion of the body's centre of mass caused by the impeding of natural arm swing patterns. The subsequent effect on the potential development of injuries in rifle carriers is unknown.     

冰风荷载作用下架空线路脱冰跳跃风险评估方法

本文提出了一种用于评估架空线路在冰风荷载作用下脱冰风险的方法。通过仿真获取不同脱冰模式下的竖向冰跳高度、横向摆幅和端部动态张力的变化数据。进而计算输电线路相间最小间隙、冲击倍数、悬垂线夹最大不平衡张力及耐张绝缘子串的安全系数。结合这些参数,定量分析了放电、断线、线夹损害和绝缘子串损坏的风险,并输出了综合风险评估。此外,本研究引入阶跃函数来模拟脱冰和风荷载,提出了计算脱冰线路最小相间隙的新方法。以中国南方某110kV架空线路为例,验证了该方法的有效性。结果显示,C相导线脱冰导致张力大幅下降,竖向跳跃高度和横向摆幅分别达1.84m和11.6m,耐张串和悬垂线夹的不平衡张力分别高达44kN和85kN,暴露出电气和力学方面的风险。该评估与实际事故相符,证明了方法的准确性。     

基于Adams/Car的汽车前悬架仿真分析及优化设计

针对某车型的麦弗逊前悬架系统,用车辆多体动力学仿真软件Adams/Car建立该悬架的虚拟样机模型,对其进行双轮同向跳动激振仿真分析,并综合评价该悬架的车轮定位参数、主销后倾拖距和转向角随轮跳的响应特性.在仿真分析的基础上,针对不合理的结构设计参数,利用Adams/Insight模块进行基于设计变量灵敏度分析的优化设计.优化后的悬架参数能很好地满足设计要求,从而达到提高该悬架系统整体性能的目的.