EFFICIENCY ANALYSIS OF DOUBLE CRANK RING-PLATE-TYPE PIN-CYCLOIDAL GEAR PLANETARY DRIVE

From the general formula for calculating the efficiency of planetary geartrains, the efficiency of the double crank ring-plate-type pin-cycloidal gear planetary drive isderived. To prove the theory, an experimental study has been conducted. The tested value of theefficiency of a sample set of the new-type drive in the experiment agrees with the calculated one.It shows that the new-type drive is of not merely high bearing capacity, but also quite highefficiency.

Double Position Servo Synchronous Drive System Based on Cross-Coupling Integrated Feedforward Control for Broacher

Synchronization errors directly deteriorate the machining accuracy of metal parts and the existed method cannot keep high synchronization precision because of external disturbances. A new double position servo synchronous driving scheme based on semi-closed-loop cross- coupling integrated feedforward control is proposed. The scheme comprises a position error cross-coupling feedfor-ward control and a load torque identification with feed- forward control. A digital integrated simulation system for the dual servo synchronous drive system is established. Using a 20 t servo broacher, performance analysis of the scheme is conducted based on this simulation system and the simulation results show that systems with traditional parallel or single control have problems when the work- table works with an unbalanced load. However, the system with proposed scheme shows good synchronous perfor- mance and positional accuracy. Broaching tests are performed and the experimental results show that the maximum dual axis synchronization error of the system is only 8μm during acceleration and deceleration processes and the error between the actual running position and the given position is almost zero. A double position servo synchronous driving scheme is presented based on crosscoupled integrated feedforward compensation control, which can improve the synchronization precision.

Simulation on model predictive control for PMSM drive system based on double extended state observer

A novel double extended state observer(DESO)based on model predictive torque control(MPTC)strategy is developed for three-phase permanent magnet synchronous motor(PMSM)drive system without current sensor.In general,to achieve high-precision control,two-phase current sensors are necessary for successful implementation of MPTC.For this purpose,two ESOs are used to estimate q-axis current and stator resistance respectively,and then based on this,d-axis current is estimated.Moreover,to reduce torque and flux ripple and to improve the performance of the torque and speed,MPTC strategy is designed.The simulation results validate the feasibility and effectiveness of the proposed scheme.

LOAD DISTRIBUTION ON DRUMS OF DOUBLE DRIVE BELT CONVEYOR

The double drum drive is widely used on the mine belt conveyor, which are divided the rigid connected double drums and separately driving double drums according to connected method of two drums. Because of the change of real work condition, the load distribution is changed on the two drive drums, which may produce a slippage between a drum and belt. Slippage may intensify the wear of the drum, and sometimes causing the fire of the belt. This restricts the development toward narrow belt, high velocity and large power of belt conveyor. In this paper, the factors affecting the load distribution of two drums of double drum belt conveyor are systematically analyzed and some computing formulas derived, by these formulas, the actual lcad distribution on the two drums of rigid connected or separately driving belt conveyor can be separately calculated.These formulas also can be as the theory base for adjusting the driving force of two drums.

Research on Angular Output Velocity of a Drive Shaft with Double Cross Universal Joints

The study object is the angular output velocity of the drive shaft which is made up of two series-wound cross universal joints. We have deduced the function relation between the angular output velocity and initiative input angle of the drive shaft with double cross universal joints that is based on the calculation formula of the angular output velocity of a single cross universal joint, and by analyzing the relation between the two input angles. By using this function relation, the constant velocity condition of the drive shaft with double cross universal joints＂ is verified. The step-by-step searching algorithm is adopted to obtain the optimal phase angle that leads to the minimum fluctuate index of the angular output velocity in the vary velocity condition. At the same time, we worked out the maximal and minimum value of the angular output velocity, and their initiative input angle. The correctness of the function of the angular output velocity and the step-by-step search algorithm are verified by an ADAMS simulation example.

Phase-dependent double optomechanically induced transparency in a hybrid optomechanical cavity system with coherently mechanical driving

We propose a scheme that can generate tunable double optomechanically induced transparency in a hybrid optomechanical cavity system.In this system, the mechanical resonator of the optomechanical cavity is coupled with an additional mechanical resonator and the additional mechanical resonator can be driven by a weak external coherently mechanical driving field.We show that both the intensity and the phase of the external mechanical driving field can control the propagation of the probe field, including changing the transmission spectrum from double windows to a single-window.Our study also provides an effective way to generate intensity-controllable, narrow-bandwidth transmission spectra, with the probe field modulated from excessive opacity to remarkable amplification.

Torque analysis for double-stator permanent-magnet motor

In addition to the characteristics of a conventional motor, a novel direct-drive double-stator permanent-magnet brushless motor proposed can operate in the state of either a generator or a motor as appropriate. Through numerical calculation and analysis, the output torque of double-stator permanent-magnet brushless motor of the same volume as the traditional machine is discussed, and the reduction of torque ripple by using the structure features of this motor is investigated. The results indicate that lower torque ripple under the condition of ideal effective torque can be obtained by the rational design of motor. The prototype motors tested show that this kind of motor structure has a higher power density.

双缸液压驱动系统灰色预测模糊PID控制研究

为了提高双缸液压驱动系统非线性变化力的跟踪精度,使驱动力变化相对稳定,设计了灰色预测模糊比例积分微分(PID)控制器,并对驱动力跟踪效果进行仿真验证。为了对双缸液压驱动系统工作原理进行介绍,绘制了双缸液压驱动系统装置简图。针对传统PID控制器进行改进,结合模糊推理和灰色预测理论,设计出灰色模糊PID控制器,并且给出了双缸液压驱动系统控制过程。利用灰色补偿提高控制器的抗干扰能力,采用Matlab软件对双缸液压驱动系统非线性力的变化跟踪进行仿真,与改进前的控制效果进行对比。结果显示:在无干扰环境中,采用PID控制、模糊PID控制和灰色预测模糊PID控制方法,均能提高双缸液压驱动系统力的变化跟踪精度,这3种控制器控制效果相差不大。在有干扰环境中,灰色预测模糊PID控制方法明显优于PID控制和模糊PID控制方法。双缸液压驱动系统采用灰色预测模糊PID控制方法,能够抑制外界波形的干扰,从而提高控制系统的稳定性。

一种雷达转台双电机驱动系统设计与同步控制方法

作为机械传动系统的一个重要组成,转台被广泛应用于雷达系统中,为满足雷达检测等领域对转台驱动系统惯量、功率、性能方面的要求,提出采用双电机同步驱动转台的方式。利用双电机伺服系统的电消隙原理和差速耦合负反馈的同步控制方法,由控制器将控制量经数/模转换送入驱动器,以实现系统的消隙功能、同步补偿功能,提高转台驱动系统的精度和同步控制性能,并将其运用到雷达转台伺服系统中,结果证明了方法的可行性,能够提高所设计雷达转台双电机驱动系统的精确性。

双碳背景下中国制浆造纸产业碳效率时空分布特征研究

我国的制浆造纸产业不仅是国民经济的重要支柱,还面临着能源消耗大、污染物排放量高的挑战。在这样的背景下,深入了解并分析该产业的碳排放情况,对推动行业的绿色转型和实现碳减排目标具有不可小觑的作用。首先,通过探讨造纸行业碳效率的计算方法,综合考察了2002年至2014年我国及各主要省份造纸及纸制品行业的碳排放总体情况及其强度变化,揭示了行业碳排放的地域分布和时间演变规律,进一步识别了驱动制浆造纸产业碳效率变动的关键因素,为产业政策制定提供了科学依据。其次,结合当前我国经济发展与低碳经济转型的大环境,提出了针对制浆造纸产业的碳减排策略。

特厚煤层沿空掘巷围岩支卸协同控制技术

针对特厚煤层小煤柱沿空掘巷大范围塑性全煤巷道锚网索的支护难题,以塔山煤矿8204-2小煤柱工作面为工程背景,采用现场实测、理论分析等方法,揭示了锚杆、锚索对沿空大范围塑性全煤巷道的支护机理。锚杆支护主要作用于浅部二次破碎区煤体,形成浅部连续承载结构;锚索主要作用于深部处于三向受力状态的稳定煤体,形成更大范围的连续稳定承载结构;进一步明确了锚杆、锚索有效长度的计算方法,形成了以高预紧力、高强“锚-网-索”支护为基础,以坚硬顶板井下磨料水射流切顶卸压、巷帮大直径钻孔卸压、底板卸压槽卸压为辅的“支卸协同”小煤柱沿空巷道围岩控制技术体系。工程应用结果表明,试验巷道围岩最大变形量小于700 mm,能够满足使用要求。

高速公路立体复合扩容设计的仿真模型研究

针对传统交通仿真技术在高速公路立体复合扩容场景存在评估精度不足、应用效果甚微的问题,提出了一种面向高速公路立体复合扩容设计的仿真模型构建方法。选取深圳市机荷高速改扩建工程为研究对象,梳理路网设施、交通需求数据、驾驶行为模型参数等3大仿真模型建模要素,提出仿真建模的技术流程;对包含互通立交、收费站、上下匝道等重点基础设施的全路网进行仿真建模,基于交通量预测模型获取项目范围的出行OD矩阵,完成交通需求建模;引入驾驶模拟仿真技术,构建高速公路立体复合扩容的驾驶模拟场景,设计并开展驾驶模拟实验,采用K均值聚类算法将驾驶行为划分为激进、保守、正常3个类别,并分别分析驾驶行为特征,据此对仿真驾驶行为模型参数进行标定,提升仿真模型精度。仿真结果表明:该模型构建方法,可以有效标定期望速度、车头时距、临界间隙等参数,从而提升仿真模型分析精度。

自动化决策系统语境中不作为因果关系之司法证明

智能辅助驾驶等自动化决策系统的成熟引发的证据法问题,是如何运用证据认定“机器的不作为”与损害结果之间具有事实上的因果关系,为此,可引入双重相关性证明理论加以解决。不作为因果关系的实体法构成要件要素包括作为可能性与结果回避的统计概率,其中,结果回避的统计概率建立在作为可能性基础上。实体法上的作为可能性在证据层面对应的待证事实,是因果干预的能力事实和能力的触发条件事实。在进行证据调查时,所有可采纳的证据材料需满足双重相关性要求,即证据材料与待证的能力事实和条件事实的相关性,以及能力及其触发条件与结果得到避免的假设之间的相关性。在进行事实重建时,应运用“二次重建”方法,在第一次重建中,事实认定者必须使用所有可采证据来重建行为人(自动化决策系统)的干预能力和能力的触发条件,而后在第二次重建中,他需要基于这些能力和条件,重建行为人(自动化决策系统)避免结果发生的行动计划、过程及其可能的成效,并根据第二次重建来计算结果回避的统计概率。

神东矿区煤矿掘进工艺及装备智能化技术研究

为了实现神东煤炭集团煤矿巷道掘进由人控到数控、由自动到智能的全面提速,分析了神东矿区煤矿单巷掘进、双巷掘进、大断面切眼贯通的工艺及设备配套技术现状,研究了智能化掘锚一体机、智能化连续采煤机、智能掘锚一体机惯性导航技术、成套智能化掘进技术、近端AI识别和远程云控制技术等掘进设备智能化技术,同时研究了预埋孔钻进机器人、智能化管路抓举设备、智能化防爆柴油开槽机、电缆自动收放车辆、智能清仓机器人等掘进辅助作业设备及技术。在此基础上给出神东煤炭集团煤矿掘进智能化发展建议,即:加快推广掘锚一体化生产工艺、发展5G无线网络技术、完善透明地质保障系统等,从根源上解决智能设备自主可控、智能互联、安全可信等关键问题。

双圆弧弧齿锥齿轮章动传动啮合齿轮本体温度的相关影响因素分析

啮合温度影响双圆弧弧齿锥齿轮章动传动过程中的疲劳、振动、噪声等行为,在双圆弧弧齿锥齿轮的寿命预测和力学响应时不可忽视。为了揭示双圆弧弧齿锥齿轮章动传动本体温度场分布规律,对双圆弧弧齿锥齿轮进行齿面接触分析,得到啮合区间;结合摩擦学和传热学得到齿轮的热载荷,建立了双圆弧弧齿锥齿轮温度有限元数值模型;采用控制变量法,分析了相关影响因素对锥齿轮温度的影响规律及原因。结果表明,齿轮温度随模数的增大而降低,随螺旋角的增大而升高,随章动角的增大先降低再升高;润滑油温度对本体温度的影响呈线性关系。研究为降低齿轮高温失效风险提供了参考。

基于目标定尺的双偏心摆式飞剪机控制参数计算

研究了双偏心摆式飞剪连续定尺剪切原理,建立了目标定尺长度计算模型,形成比较完善的基于目标定尺长度的双偏心摆式飞剪传动控制参数计算方法。设定曲轴转动角速度曲线,建立速度方程式,解析求解得到曲轴转动角速度,从而得到角加速度、加减速时间、匀速转动角速度、匀速运行保持时间等控制参数。并通过某汽车板连续镀锌机组的双偏心摆式飞剪机进行编制程序和控制计算验证,计算速度快,精度高,完全满足工程需要。

排管机械手扶持装置的研制

扶持装置在排管机械手中起扶持管柱的作用,是排管装置重要的组成部分之一。文中介绍了单驱动双作用扶持装置的结构组成、工作流程及试验情况。该单驱动双作用扶持装置的成功设计,节约了排管机械手生产制造成本,降低了故障率,提升了排管机械手的性能,对排管机械手的发展具有重要意义。

一种复合驱动并联机构的设计与运动学分析

提出了一种新型的5自由度复合驱动并联机构,并对其进行了运动学分析。首先,根据复合驱动并联机构的构型特点,开展了伴随运动分析,推导得到了位置逆解计算公式;其次,通过分析动平台上一组点的线速度分量与驱动速度间的映射,推导出5×5齐次量纲的雅可比矩阵;采用离散法计算机构的可达工作空间,根据灵活度指标,即条件数的倒数在可达工作空间的分布情况,确定了许用工作空间位置;然后,通过分析最大压力角在机构许用工作空间中的分布情况和驱动力与机构末端受力之间的映射关系,完成了并联机构的奇异性分析;最后,基于MATLAB和ADAMS软件进行了运动学仿真验证。所述工作为下一代样机的优化设计提供了理论基础。

进口贸易促进创新示范区建设对我国产业结构优化升级的影响——基于双重差分模型的实证研究

以2009—2021年282个城市面板数据为基础,采用双重差分法实证检验国家进口贸易促进创新示范区建设对产业结构优化升级的影响及其作用机制。研究结果表明,示范区建设显著促进产业结构整体升级。具体而言,示范区建设通过金融发展效应、人才集聚效应、创新驱动效应等机制推动产业结构整体升级。此外,示范区建设对不同地区产业结构的影响存在异质性。从扩大试点范围、差异化建设、“示范区建设+人才培养”组合拳等方面提出了对策建议,以进一步加大产业结构升级的力度,实现更精准的产业优化升级。