介绍几种齿轮消隙的典型结构

总结了几种齿轮消隙的典型结构,并简要介绍了斜齿轮轴向垫片调整法、偏心轴套调整法和轴向弹簧调整法的结构及消除方法.     

蛇形机器人的转弯和侧移运动研究

介绍了沈阳自动化研究所研制的蛇形机器人机械结构和控制结构。在分析蛇形曲线的基础上,提出幅值调整法、相位调整法和侧移调整法三种新方法,来处理蛇形机器人侧向滑动带来的方位偏转和完成蛇形机器人自主转弯控制,并给出几种方法的量化关系,建立动力学仿真模型进行了运动仿真。幅值调整法虽然使蛇形机器人转弯角度受到限制但却保证了运动的连续性和稳定性。相位调整法能够使蛇形机器人准确地完成转弯运动。侧移调整法能够实现蛇形机器人前进过程中的侧向位置调整,同时保证运动方向的准确性。将上述方法应用到蛇形机器人的控制中,用仿真和试验验证了以上方法的有效性。     

可重构单体机器人动力学分析与控制

给出了可重构机器人在移动过程中的动力学模型,并提出了相应两种控制方法,即构形调整法和状态调整法。通过仿真试验得到,构形调整法能够在不影响状态的情况下,同时满足机器人运动稳定性和越障性的要求,增强了机器人运动的鲁棒性。     

约束网络及约束传播技术在并行设计中的应用研究

探讨人工智能中的约束网络及约束传播技术的并行设计中的应用,先将设计变量构成约束网络,通过约束传播技术使得设计变量趋于精确,并将推理依据进行记录,在发生冲突时系统呆以根据所记录的约束来源协调设计过程,达到协同设计的目的。     

GPT-1型光栅偏心调整检验仪

从光栅副形成莫尔条纹的特性方程出发 ,分析了对电子经纬仪的光栅副偏心调整的四种方法 :莫尔条纹调整法、漏缝调整法、基圆调整法和基于李萨茹圆的电调整法。根据实际情况 ,确定了对光栅偏心调整采用基于 CCD图像系统的基圆调整法进行粗调 ,和基于虚拟数字示波器的精调法相结合的方案 ,采用曲线拟合和相关法 ,计算出光栅偏心的大小与方位 ,并给出了光栅偏心与轴晃的关系 ,介绍了 GPT- 1型光栅偏心调整检验仪的组成和功能 ,最后给出了仪器的调整检验结果。实践表明 ,GPT- 1型光栅偏心调整检验仪为电子经玮仪的装配、光栅偏心调整和偏心检验起到了重要的指导作用 ,大大地提高了生产效率     

基于I-DEAS的数字化工厂建模技术研究

针对大型工厂的数字化建设中的底层模型开发技术,提出了基于I-DEAS的三维实体模型的计算几何学表达。研究了CAD建模技术:参数化设计技术和变量化设计技术,及这两种建模技术的约束求解方式,提出了基于参数驱动的工厂配置约束方法和配置管理技术。     

电化学加工阴极设计边界调整法

针对电化学加工阴极设计这一有势场Laplace逆问题，给出了一种阴极设计方法——阴极边界调整法。该方法在假设阴极边界已知的情况下，采用有限元计算获得阳极边界电场分布，并求与实际阳极电场分布间的方差和。若此方差和在规定的误差范围内，则此时对应的假设阴极边界即为所求阴极边界。否则，调整阴极边界进行迭代计算，直到方差和满足要求为止。计算和实验结果表明，阴极边界调整法收敛性较好，迭代次数适当，能满足设计要求。     

具有不可控变迁的离散事件系统Petri网控制器的研究

针对基于Petri网建模的离散事件系统的Petri网控制器的设计问题,分析了系统中存在不可控变迁时的情况,并基于局部设计和Petri网简化技术,提出了一种新的控制器设计方法。该方法首先将约束条件分为允许约束和非法约束,并通过矩阵转换方法将非法约束转换为允许约束,然后通过约束矩阵设计出相应的控制器。该方法由于只考虑与约束库所、约束变迁及不可控变迁相关联的局部关联矩阵,降低了矩阵的维数,简化了控制器的设计,避免了死锁。最后,基于两个实例验证了该方法的高效性。     

固体发动机变量化设计关键技术研究

在固体发动机概念设计阶段引入变量化设计技术,旨在实现发动机概念/结构的一体化设计。文中对变量化涉及的关键支撑技术——几何约束求解算法的构造、工程约束与几何约束的耦合及统一求解和几何造型平台的选择进行了详细的探讨。然后设计了一个变量化约束求解器的架构,并在此基础上结合固体发动机设计领域的特殊要求订制了固体发动机变量化方案设计流程。笔者的研究是后续构建固体发动机变量化设计环境的基础,为后续工作的开展做了先行性探讨。     

GPT一1型光栅偏心调整检验仪

从光栅副形成莫尔条纹的特性方程出发，分析了对电子经纬仪的光栅副偏心调整的四种方法：莫尔条纹调整法、漏缝调整法、基圆调整法和基于李萨茹圆的电调整法。根据实际情况，确定了对光栅偏心调整采用基于CCD图像系统的基圆调整法进行粗调，和基于虚拟数字示波器的精调法相结合的方案，采用曲线拟合和相关法，计算出光栅偏心的大小与方位，并给出了光栅偏心与轴晃的关系，介绍了GPT一1型光栅偏心调整检验仪的组成和功能，最后给出了仪器的调整检验结果。实践表明，GPT一1型光栅偏心调整检验仪为电子经纬仪的装配、光栅偏心调整和偏心检验起到了重要的指导作用，大大地提高了生产效率。     

Optimization of aero-engine pipeline for avoiding vibration based on length adjustment of straight-line segment

In the design and troubleshooting of aero-engine pipeline, the vibration reduction of the pipeline system is often achieved by adjusting the hoop layout, provided that the shape of pipeline remains unchanged. However, in reality, the pipeline system with the best antivibration performance may be obtained only by adjusting the pipeline shape. In this paper, a typical spatial pipeline is taken as the research object, the length of straight-line segment is taken as the design variable, and an innovative optimization method of avoiding vibration of aero-engine pipeline is proposed. The relationship between straight-line segment length and parameters that determine the geometric characteristics of the pipeline, such as the position of key reference points, bending angle, and hoop position, are derived in detail. Based on this, the parametric finite element model of the pipeline system is established. Taking the maximum first-order natural frequency of pipeline as the optimization objective and introducing process constraints and vibration avoidance constraints, the optimization model of the pipeline system is established. The genetic algorithm and the golden section algorithm are selected to solve the optimization model, and the relevant solution procedure is described in detail. Finally, two kinds of pipelines with different total lengths are selected to carry out a case study. Based on the analysis of the influence of straight-line segment length on the vibration characteristics of the pipeline system, the optimization methods developed in this paper are demonstrated. Results show that the developed optimization method can obtain the optimal single value or interval of the straight-line segment length while avoiding the excitation frequency. In addition, the optimization efficiency of the golden section algorithm is remarkably higher than that of the genetic algorithm for length optimization of a single straight-line segment.     

Design and analysis of a new AUV’s sliding control system based on dynamic boundary layer

The new AUV driven by multi-vectored thrusters not only has unique kinematic characteristics during the actual cruise but also exists uncertain factors such as hydrodynamic coefficients perturbation and unknown interference of tail fluid,which bring difficult to the stability of the AUV’s control system.In order to solve the nonlinear term and unmodeled dynamics existing in the new AUV’s attitude control and the disturbances caused by the external marine environment,a second-order sliding mode controller with double-loop structure that considering the dynamic characteristics of the rudder actuators is designed,which improves the robustness of the system and avoids the control failure caused by the problem that the design theory of the sliding mode controller does not match with the actual application conditions.In order to avoid the loss of the sliding mode caused by the amplitude and rate constraints of the rudder actuator in the new AUV’s attitude control,the dynamic boundary layer method is used to adjust the sliding boundary layer thickness so as to obtain the best anti-chattering effects.Then the impacts of system parameters,rudder actuator’s constraints and boundary layer on the sliding mode controller are computed and analyzed to verify the effectiveness and robustness of the sliding mode controller based on dynamic boundary layer.The computational results show that the original divergent second-order sliding mode controller can still effectively implement the AUV’s attitude control through dynamically adjusting the sliding boundary layer thickness.The dynamic boundary layer method ensures the stability of the system and does not exceed the amplitude constraint of the rudder actuator,which provides a theoretical guidance and technical support for the control system design of the new AUV in real complex sea conditions.     

Filtering technique to control member size in topology design optimization

A simple and effective filtering method to control the member size of an optimized structure is proposed for topology optimization. In the present approach, the original objective sensitivities are replaced with their relative values evaluated within a filtering area. By adjusting the size of the filtering area, the member size of an optimized structure or the level of its topological complexity can be controlled even within a given finite element mesh. In contrast to the checkerboard-free filter, the present filter focuses on high-frequency components of the sensitivities. Since the present filtering method does not add a penalty term to the objective function nor require additional constraints, it is not only efficient but also simple to implement. Mean compliance minimization and eigenfrequency maximization problems are considered to verify the effectiveness of the present approach.     

Trajectory planning of mobile robots using indirect solution of optimal control method in generalized point-to-point task

This paper presents an optimal control strategy for optimal trajectory planning of mobile robots by considering nonlinear dynamic model and nonholonomic constraints of the system. The nonholonomic constraints of the system are introduced by a nonintegrable set of differential equations which represent kinematic restriction on the motion. The Lagrange’s principle is employed to derive the nonlinear equations of the system. Then, the optimal path planning of the mobile robot is formulated as an optimal control problem. To set up the problem, the nonlinear equations of the system are assumed as constraints, and a minimum energy objective function is defined. To solve the problem, an indirect solution of the optimal control method is employed, and conditions of the optimality derived as a set of coupled nonlinear differential equations. The optimality equations are solved numerically, and various simulations are performed for a nonholonomic mobile robot to illustrate effectiveness of the proposed method.     

On-Machine Measurement of the Straightness and Tilt Errors of a Linear Slideway Using a New Four-Sensor Method

Although there are some multi-sensor methods for measuring the straightness and tilt errors of a linear slideway, they need to be further improved in some aspects, such as suppressing measurement noise and reducing precondition.In this paper, a new four-sensor method with an improved measurement system is proposed to on-machine separate the straightness and tilt errors of a linear slideway from the sensor outputs, considering the influences of the reference surface profile and the zero-adjustment values. The improved system is achieved by adjusting a single sensor to di erent positions. Based on the system, a system of linear equations is built by fusing the sensor outputs to cancel out the e ects of the straightness and tilt errors. Three constraints are then derived and supplemented into the linear system to make the coe cient matrix full rank. To restrain the sensitivity of the solution of the linear system to the measurement noise in the sensor outputs, the Tikhonov regularization method is utilized. After the surface profile is obtained from the solution, the straightness and tilt errors are identified from the sensor outputs. To analyze the e ects of the measurement noise and the positioning errors of the sensor and the linear slideway, a series of computer simulations are carried out. An experiment is conducted for validation, showing good consistency. The new four-sensor method with the improved measurement system provides a new way to measure the straightness and tilt errors of a linear slideway, which can guarantee favorable propagations of the residuals induced by the noise and the positioning errors.     

3D geometric constraint solving using the method of kinematic analysis

In this paper, an approach based on kinematic method for solving 3D geometric assembly constraints is presented. The relative generalized coordinates and generalized recursive formulations used in kinematic analysis are utilized to reduce the size of constraint equations. Based on the cut-constraint method, this approach can be used to solve all kinds of configurations. In the case of an open-loop constraint system, the geometric constraints can be satisfied by sequentially determining the values of relative generalized coordinates. With respect to a closed-loop constraint system, the proposed approach converts it to a spanning tree structure by cutting constraints and introducing cut-constraint equations. Furthermore, a topological analysis method is also developed to obtain the spanning tree with the minimal number of cut-constraint equations, and the analytical Jacobian matrix of cut-constraint equations is derived to enhance computational efficiency. In the end, the proposed approach is demonstrated and validated using two examples of closed-loop geometric constraint system.     

A priori checking inconsistencies among strategic constraints for assembly plan generation

This paper is related to the field of assembly plan generation. It describes a new approach to a priori check the consistency of an assembly strategy that is given by the assembly system designers before running an assembly plan generation algorithm. The aim of this work is to improve the assembly plan designer’s efficiency by reducing the research space while proving the existence of acceptable solutions. The assembly strategy combined with the product’s model implies a set of constraints on the assembly processes. The proposed method determines whether the given assembly strategy produces possible assembly processes. In case of inconsistencies among the strategic constraints, the method will help the designer to identify the contradictory constraints. The set of constraints can be expressed by a Boolean equation. First we present the key concepts and models related to the product, processes, and added values in the field of assembly plan generation. Second we define existing strategic constraints, and propose three new ones and a classification of strategic assembly constraints. The originality of the proposed method consists in defining an elementary strategic constraint that is used to describe every other constraint. The proposed method leads to model an assembly strategy by a single Boolean equation that is used to check the inconsistencies. An industrial case study is provided to highlight and to demonstrate the interests of this approach.     

基于CCD视频幅值调节器的目标精确定位方法

为了应用固定双阈值法进行边界检测并利用灰度重心法进行像元细分,以实现对点目标的精确定位,设计了线阵CCD 视频幅值调节器反馈控制系统。通过对光积分时间和程控增益2环节的定量数控调节,使光点图像目标的尖峰灰度幅值保持恒定,显著降低了对光源和光路的设计难度和成本。固定双阈值边界检测定位法和传统的二值化方法相比,不需要额外的二值化参考电平硬件电路,系统更加简单可靠,算法更优秀,可以实现小于1/10像元的细分效果,在工程应用上实现了对光点的精确定位。该2变量无级调光数控系统方案对多变量摄像调光系统的设计有重要的参考价值。     

Treatment of kinematic constraints of multirigid body system dynamics and their application to manipulation-robots

In this paper a general method for describing multirigid body systems is represented, which uses a special notation of open loop kinematical chains and three types of elementary constraints. The dynamic model is automatically generated in a numerical way. It is proposed to treat the natural (physical) or artificial constraints in a unified sense and include both in the generalized dynamic problem. The generalized dynamic problem is formulated as an initial-value problem of a nonlinear system of algebraic differential equations and is solved by a multistep technique combined with a Newton method.

This method was successfully tested in the software-package CAE-IR. Some applications of the elementary constraints are represented.     

半导体激光器在准直光学系统中的调整装置

介绍了一种利用半导体激光器在准直光学系统中的调整装置,解决了光电检测仪器中发光器件、光电探测器件定位问题。