Exploratory Study on the Simulated Police Force Allocation of Shopping Mall Emergency Based on AnyLogic Platform

Due to the rapid development of society,public places,especially large shopping malls,are relatively frequent places for emergencies.Such emergencies not only seriously affect public security and property,but also bring great psychological pressure to citizens.Therefore,this study is of great significance for the exploration and study of public place emergencies.The research object of this study is the public shopping mall.Based on the AnyLogic simulation platform and guided by the relevant principles of social force model,this study utilize the pedestrian storehouse in the platform as the core module to build the simulation environment,and attempts to simulate the police force restraining effect on the overall event and the perpetrators after the occur of emergent incident under different police force allocations.In order to ensure the accuracy of the experimental data,the research team conducted field survey to estimate the average flow of people and the general data of the security personnel in shopping malls,also estimated the rest rain and capture time after repeated experiments.The results indicate that increasing additional police force outside the shopping malls and pre-organizing reasonable patrol routes can obviously facilitate police officers to restrain perpetrators.Meanwhile,it is also clear that the AnyLogic platform can effectively simulate pedestrian movement and interaction behaviour in emergencies.

Force modeling for needle insertion into soft tissue based on mechanical properties and geometric parameters

The force model during needle insertion into soft tissue is important for accurate percutaneous intervention.In this paper,a force model for needle insertion into a tissue- equivalent material is presented and a series of experiments are conducted to acquire data from needle soft- tissue interaction process.In order to build a more accurate insertion force model,the interaction force between a surgical needle and soft tissue is divided into three parts:stiffness force,friction force,and cutting force.The stiffness force is modeled on the basis of contact mechanics model.The friction force model is presented using a modified Winkler' s foundation model.The cutting force is viewed as a constant depending on a given tissue.The proposed models in the paper are established on the basis of the mechanical properties and geometric parameters of the needle and soft tissue.The experimental results illustrate that the force models are capable of predicting the needle-tissue interaction force.The force models of needle insertion can provide real-time haptic feedback for robot-assisted procedures,thereby improving the accuracy and safety of surgery.

Interaction forces between soft magnetic particles in uniform and non-uniform magnetic fields

The influence of the magnetization of a soft magnetic sphere on the surrounding magnetic field is measured and characterized.The interaction force between two soft magnetic particles is directly measured using an ultra precision load sensor in uniform and non-uniform magnetic fields. The interaction force largely follows an inverse fourth power law as a function of separation distance between particle centers. At small distances,the effect of magnetization of one particle on the magnetization of its adjacent particle causes the attractive（repulsive） force to be larger（smaller） than that predicted by the inverse fourth power law.The theoretical prediction based on a modified dipole model,that takes into account the coupling effect of the magnetization among soft magnetic particles,gives excellent agreement with the measured force in a uniform magnetic field.The interaction force under a non-uniform applied magnetic field can be reasonably predicted using the dipole-dipole interaction model when the local magnetic field is used to determine the magnetization.

Thorn-Shape Waveform and Double-Strike Phenomenon Seen in the Impact Force of Soft Materials

In the impact tests of soft materials, we sometimes observe a thorn shape in the rising segment of the impact force waveform. However, the reason for the occurrence of the thorn shape has not been made clear. In this study, thorn-shape waveforms of several soft materials are measured using compact drop test equipment under the condition of a flat frontal impact. A flat frontal impact is the condition where a drop hammer with a flat bottom surface strikes a plate-like soft material in the normal direction. Synchronized impact forces are measured using two sensors installed on both the drop hammer side and the floor side. The examined soft materials are a sponge sheet, sponge rubber sheet, gel sheet, rubber sheet, flat oil clay, low-rebound urethane foam, cork sheet, sliced ham, pork ham steak, and pork. Based on the test results, the features of the thorn-shape waveforms are discussed from a bird’s-eye view. Furthermore, the occurrence mechanism of the thorn-shape waveforms is discussed from the viewpoint of viscosity discontinuity and the double-strike phenomenon.

A Novel Pneumatic Soft Gripper with a Jointed Endoskeleton Structure

In current research on soft grippers,pneumatically actuated soft grippers are generally fabricated using fully soft materials,which have the advantage of flexibility as well as the disadvantages of a small gripping force and slow response speed.To improve these characteristics,a novel pneumatic soft gripper with a jointed endoskeleton structure(E-Gripper)is developed,in which the muscle actuating function has been separated from the force bearing function.The soft action of an E-Gripper finger is performed by some air chambers surrounded by multilayer rubber embedded in the restraining fiber.The gripping force is borne and transferred by the rigid endoskeleton within the E-Gripper finger Thus,the gripping force and action response speed can be increased while the flexibility is maintained.Through experiments,the bending angle of each finger segment,response time,and gripping force of the E-Gripper have been measured,which provides a basis for designing and controlling the soft gripper The test results have shown that the maximum gripping force of the E-Gripper can be 35 N,which is three times greater than that of a fully soft gripper(FS-Gripper)of the same size.At the maximum charging pressure of 150 kPa,the response time is1.123 s faster than that of the FS-Gripper.The research results indicate that the flexibility of a pneumatic soft gripper is not only maintained in the case of the E-Gripper,but its gripping force is also obviously increased,and the response time is reduced.The E-Gripper thus shows great potential for future development and applications.

Anchoring mechanism and application of hydraulic expansion bolts used in soft rock roadway floor heave control

Comparing with the resin bolt, the hydraulic expansion bolt has different anchoring mechanism and application advantage. According to the working mechanism of the hydraulic expansion bolt, its anchoring force is expressed in four forms including support anchoring force, tension anchoring force, expansion anchoring force and tangent anchoring force, and their values can be obtained on the basis of each calculation formula. Among them, the expansion anchoring force, which is the unique anchoring force of the hydraulic expansion bolt, can provide confining pressure to increase the strength of rock. Aiming at solving the problem of stability control in the soft rock roadway in Jinbaotun Coal Mine which has a double layer of 40 U-type sheds and cannot provide enough resistance support to control floor heave, the study reveals the mechanism of floor heave in the soft rock roadway, and designs the reasonable support parameters of the hydraulic expansion bolts. The observed results of floor convergence indicate that the hydraulic expansion bolts can prevent the development and flow of the plastic zone in the floor rock to control floor heave. Research results enrich the control technology in the soft rock roadway.

Viscosity Transient Phenomenon in Drop Impact Testing of Soft Material

The authors carried out drop impact tests for several soft materials under a flat frontal impact condition in which a drop hammer with a flat bottom surface strikes a plate-like soft material in the normal direction. The experimental results indicated that the impact force waveforms of soft materials consisted of a thorn-shaped waveform and a subsequent mountain-shaped waveform. The thorn-shaped waveform was strongly affected by the strain rate. In the present study, the occurrence mechanism of this distinctive waveform was discussed from the viewpoint of the viscosity transient phenomenon. A standard linear solid (SLS) model in which the viscosity transient phenomenon was considered was applied to the simulation. Some features of the impact force waveform of soft materials could be explained by the SLS model. Furthermore, the thorn-shape waveform could also be observed in the impact force waveforms of human skin and free-falling hollow balls.

Engineering study on roadway support in high-stress composite soft rock

The present study is focused on the roadway support in high stress composite soft rock. This paper expounds the two main features of roadway in soft rock, i.e., great deformation of surrounding rock and remarkable rheological deformation. Furthermore, on the basis of analyzing physico chemical component of surrounding rock and the situation of the damaged roadway, the method of adopting strong bolting and shotcreting mesh for the primary support, bolting and grouting for the secondary support is put forward in light of the on the spot investigation of stress tension, mechanical parameter and engineering geology. The application reveals the method facilitates the continuation of west main roadway and the restoration of shaft station and chambers. Consequently, better techno economic results have been achieved.

基于轮力感知装置的软地面通过性测试系统

针对车辆的地面通过性试验方法主要局限于模型试验而缺乏实车试验的现状,提出了一套基于轮力感知装置的软地面通过性测试系统。系统以维轮力感知装置为核心,辅以轮速传感器、视觉传感器、GPS等多种车载设备。试验结果表明本文所提出的测试系统能够在多种软地面条件下完成牵引力、滑移率等通过性关键性指标的实时测量,进而为通过性地图的建立提供有力支撑。

软土中单侧边载作用下桩基负摩阻力研究

软土中因土体压缩性较高,在边载状况下易产生桩基负摩阻力,从而对工程产生安全隐患。本文通过有限元法对软土中受边载作用的桩基础所受到的桩基负摩阻力进行数值模拟,分析了不同边载等级、不同边载位距对软土中桩基负摩阻力、中性点位置和桩身轴力的影响。结果表明,在边载等级增加时,软土中桩身轴力有明显上升趋势,并随桩体埋深增加呈非线性趋势增长,而桩基负摩阻力随深度变化呈现非线性减小的趋势,桩体的下拉力增加,边载效应增强;同等级边载效应时,当边载与桩基之间的距离增加时,软土中桩基负摩阻力逐渐减小,中性点位置位于桩体靠近底部位置处,并随边载位置改变而受到一定影响。

高校知识产权转移与转化的制度与机制研究——以武警部队院校的管理范式创新为切入

区别于普通高校高度市场化参与的知识产权开源、运作与保护模式,武警部队院校在开展知识产权转移与转化管理的过程中面临着因自身特殊性带来的资源供给、运作驱动、成果转化等界域壁垒。在高校知识产权管理陷入创新同质化的今天,推进武警部队院校知识产权转移的整合管理,应关注管理要素与资源整合的特殊性,明确机构混乱、人员缺乏、事务交杂等建设推进难点,推动知识产权管理制度与机制建设的范式转型。保障技术产出与信息传递环境中各项管理要素的安全、高效运作,建设和优化同受众需求与开发支持相契合的、内部自研与技术转移相结合的管理体系,并通过全视角的资源整合与合规优化等,完成对现有管理平台的硬性改革与软性治理。

公安民警执法武力使用规范化探微

随着我国改革开放向纵深发展,当前社会结构的变化导致社会利益矛盾时有发生。公安民警作为一线执法人员,所面临的执法环境日益复杂,且警务量繁多,工作压力巨大。近年来各地区都相继出现了暴力袭警事件,对公安民警的执法权威与职业安全产生了非常不利的影响。由于当前有关公安民警武力使用的相关法律法规不完善,且从司法层面对警察的保护力度相对比较薄弱,因此导致公安民警的执法权威与人身安全面临极大威胁。面对公安民警的武力使用问题,应从执法规范化角度出发,正视公安民警武力使用的级别与特点,分析当前公安民警武力使用过程中存在的问题,才可能找到相应的解决之策。

肺穿刺活检手术的术前演练系统研究

为解决CT引导下经皮肺穿刺活检(Percutaneous CT-guided Needle Biopsy,PCNB)对操作者要求高、术后并发症风险高等问题,设计了一个肺穿刺活检手术的术前演练系统。首先根据8位肺肿块患者CT图像分割出胸部重要器官,并基于分割结果建立病人各异的三维模型。在此基础上采用基于网格形变的方法实现穿刺过程中肺部软组织的形变模拟,并以Geomagic Touch X为基础,搭建了带有触觉反馈的肺穿刺活检术前演练环境。临床医生在行肺穿刺前使用本系统对这8位患者进行肺穿刺演练,探索合适的穿刺路径。将术前演练结果与临床实际穿刺结果对比发现两者有较好的一致性。主观问卷调查结果表明系统具有较高的真实性和易操作性。系统可用于医生进行术前演练,辅助确定合适的手术方案,提高穿刺效率和手术成功率。

板桩防波堤设计参数试验验证与规范对比研究

板桩防波堤是一种对深厚软土地基有较高适应性的防波堤结构,目前国内外应用较少。以某海外板桩防波堤工程为例,采用不规则波对不同水深处的防波堤断面开展设计波浪要素断面试验,判断护底块石、沙垫层稳定性,测量模型越浪量和防波堤迎浪侧所受波浪力分布,验证防波堤结构的安全性和合理性。最后将试验结果与国内外规范公式计算结果进行对比研究。结果表明,试验得到的波浪力及越浪结果偏于安全,防波堤设计高程合适;不同波浪状态下规范公式计算结果与试验值之间的差异不尽相同,进行具体工程设计时,需将规范公式计算与物理模型试验结合,力求设计参数合理,保证防波堤自身结构及掩护港区的安全性。

软弹流状态下“脊-膜”织构化PDMS表面增摩特性的研究

润滑条件下,增加软质材料(如橡胶、凝胶等)表面摩擦效应是柔性电子、皮肤传感器和智能抓取等功能器件设计制造的1个重大需求.本文中采用激光加工与多次覆膜相结合工艺,在PDMS(Polydimethylsiloxane,聚二甲基硅氧烷)表面加工出不同间距的“脊-膜”织构,研究其在流体润滑状态下接触界面的摩擦学特性,并原位考察了接触界面内润滑介质的流动特征.结果表明:“脊-膜”织构在滑动界面内产生周期性弹性迟滞,引起润滑界面的能量耗散,从而显著提高了PDMS表面在软弹流状态下的滑动摩擦效应;当“脊”间距为3 mm时,织构化表面的平均摩擦力可达100.23 mN,与光滑表面相比,其摩擦效应提高了49.6倍.此外,PDMS表面摩擦效应随法向载荷的增加而增加,但在不同滑动速度下基本保持不变.

水牛蹄型深海集矿机履齿设计及牵引性能研究

作为深海采矿系统的重要组成部分,深海集矿机的技术研究和开发一直是许多国家的难题。为了提高深海集矿机在稀软沉积物上的牵引性能,基于水牛蹄的曲面结构特征和特殊几何结构,设计了一款仿水牛蹄蹄型履齿。以该款履齿的结构参数为研究对象,通过对朗肯被动土压力理论的优化,得到了仿水牛蹄蹄型履齿的牵引力解析解,建立了对应的履齿仿生参数对履齿牵引力的影响公式。结合正交试验方法进行了不同形式履齿在沉积物上运动的单、多履齿剪切试验,将仿水牛蹄蹄型履齿与直型履齿、仿水牛蹄轮廓履齿(另一种仿生履齿)进行对比试验,并通过模型车试验验证了该款履齿的可行性。结果表明:3种履齿中,仿水牛蹄蹄型履齿提供的最大牵引力最高。研究可为进一步优化仿水牛蹄蹄型履齿结构参数和提高深海稀软底质机械的牵引性能提供参考依据。

主动控制下软土基坑围护结构侧向变形与迎土面土压力演化规律

基于有限分析和原位试验,对主动控制下采用轴力伺服系统的软土基坑围护结构侧向变形和迎土面土压力演化规律进行分析。研究结果表明,主动控制下基坑迎土面土压力变化与钢支撑施加轴力、围护结构侧向变形有关;主动控制下围护结构侧向变形减小时迎土面土压力增大,土体开挖工况下围护结构侧向变形增大时迎土面土压力减小;轴力对本道钢支撑处围护结构侧向变形和迎土面土压力的影响最大,距离钢支撑越远轴力对二者的影响越小;主动控制下迎土面土压力介于静止土压力与主动土压力之间;软土流变影响下围护结构侧向变形缓慢增大,迎土面土压力变化不明显。

基于变形控制的某深埋软岩水工隧洞初期支护参数的选择与验证

大变形下围岩的稳定控制一直是水利水电、公路、铁路等行业的传统难题,尚未形成一套验证软岩大变形等级下初期支护型式及参数选取的经验方法。依据某深埋水工隧洞工程地质情况,选择典型洞段预测挤压变形风险,利用控制变形估算所需支护力,依据规范和相关工程经验确定支护类型与参数的同时,考虑实际开挖过程利用数值仿真分析验算支护的合理性。结果表明,该隧洞具有极大的大变形风险,采用支护力的方法所确定的支护类型和参数基本合理,可将围岩变形有效控制在规范要求的1.0%~3.0%范围,且锚杆长度及支护应力等均未超过极限强度。

A force-closure test for soft multi-fingered grasps

This paper deals with the problem of force-closure analysis for soft multi-fingered grasps. The first step is the study of the relationship between the external wrench space and the manipulation force space at any contact. Constraint force set, strictly constraint force set and normal force set are defined in the contact force space, followed by an investigation of their relationships. Based on the convexity of the friction constraints for soft finger contact, the necessary and sufficient conditions for force-closure grasps are derived. Accordingly an efficient algorithm for testing force-closure is presented. Some illustrative examples are given.

Pneumatic and tendon actuation coupled muti-mode actuators for soft robots with broad force and speed range

Broad output force and speed ranges are highly desired for actuators to endow soft robots with high performance,thereby increasing the range of tasks they can accomplish.However,limited by their low structural stiffness and single actuation method,most of the existed soft actuators are still difficult to achieve a broad force and speed range with a relatively compact body structure.Here,we propose a pneumatic and tendon actuation coupled soft actuator(PTCSA)with multiple actuation modes,mainly composing of a multi-joint thermoplastic polyurethanes(TPU)-made skeleton sealed in a film sleeve.The TPU skeleton with certain structural stiffness combined with soft joints allows PTCSA to output small force and respond rapidly under pneumatic actuation,as well as output high force and flexibly regulate response speed under tendon actuation,therefore achieving a broad force and speed range with a compact structure.The multiple modes constructed from the two actuation methods with different force and speed properties can cover diverse application scenarios.To demonstrate its performance,PTCSA is further used to construct a soft robotic arm(with a maximum lifting speed of 198°/s and can easily lift a load of 200 g),an inchworm-inspired wheel-footed soft robot(moves at a high speed of 2.13 cm/s when unload or pulls a load of 300 g forward),and a soft gripper(can grasp diverse objects,from 0.1 g potato chips to an 850 g roll of Sn-0.7 Cu wire,from a high-speed moving tennis ball to an upright pen).This work indicates the potential of combining multiple complementary actuation methods to improve the force and speed range of soft actuators,and may provide inspiration for related research.