Hierarchical sampling optimization of particle filter for global robot localization in pervasive network environment

This paper presents a hierarchical framework for managing the sampling distribution of a particle filter (PF) that estimates the global positions of mobile robots in a large‐scale area. The key concept is to gradually improve the accuracy of the global localization by fusing sensor information with different characteristics. The sensor observations are the received signal strength indications (RSSIs) of Wi‐Fi devices as network facilities and the range of a laser scanner. First, the RSSI data used for determining certain global areas within which the robot is located are represented as RSSI bins. In addition, the results of the RSSI bins contain the uncertainty of localization, which is utilized for calculating the optimal sampling size of the PF to cover the regions of the RSSI bins. The range data are then used to estimate the precise position of the robot in the regions of the RSSI bins using the core process of the PF. The experimental results demonstrate superior performance compared with other approaches in terms of the success rate of the global localization and the amount of computation for managing the optimal sampling size.     

串联机械臂及视觉控制探究

本文从串联机器人和视觉技术的应用方面,对机器人如何通过视觉完成复杂的包装工作进行探究.     

基于改进灰狼优化算法的移动机器人路径规划

针对移动机器人避障路径规划问题,在基本群智能算法灰狼优化算法的基础上,提出改进灰狼优化算法,测试函数证明了算法的稳定性和收敛性,进而将其首次应用于移动机器人避障路径规划问题,通过对改进灰狼优化算法的移动机器人避障路径进行研究,并与基本灰狼优化算法、粒子群算法、遗传算法比较,仿真结果证明了算法的稳定性和收敛性,对路径规划领域有十分重要的研究意义。     

融合改进 Padim 建模和 ResNet 网络的 喷涂质量检测算法

为了满足喷涂机器人对于喷涂质量检测的需求,采用迁移学习对改进 Padim 建模和 ResNet 网络进行融合,构建自主喷 涂机器人喷涂质量检测一体化模型。 该模型提取一次图像特征可同时用于缺陷定位和分类。 在缺陷定位端,通过改进 Padim 模型以减少特征冗余所造成网络的计算消耗,首先将 ResNet-18 网络获取的 patch 嵌入向量语义层由原先前 3 层改为单 2 层,然 后特征表达由 100 维降维至 20 维,最后训练正样本得到正态分布模型与测试图像进行缺陷定位。 在缺陷分类端,对预训练 ResNet-18 网络进行负样本二次训练,得到 ResNet-18 分类模型对测试图像进行缺陷分类。 经过实验,将一体化模型移植在 jetson nano 移动端中,参数量仅为 11. 69 M,定位精度 94. 5%,分类准确率高达 99. 6%,在机器人位移速度 0. 02 m/ s 下检测时间 为 0. 730 s,不会出现缺帧漏检情况,满足实时检测的要求。     

Piecewise constant strain kinematic model of externally loaded concentric tube robots

This paper presents a piecewise constant strain kinematic model for concentric tube robots (CTR) in externally loaded conditions. It discretizes the pre-curved tubes comprising the robot into a finite number of pieces and involves external effects as a set of wrench vectors exerted along the robot backbone. Constant strain lets us describe the pieces with helices in which shear deformation and elongation are neglected. The resulting piecewise helix is the simplest curve that can catch the torsion of tubes that play a crucial role in kinematic behavior. This approximation transforms the conventional boundary value problem (BVP) of CTRs models into a set of nonlinear equations that drastically decreases the model resolution time. The present method uses a Lyapunov function and torsional Jacobian to ensure the distal torsion constraint consistently and, as a result, the solution’s convergence. The paper’s primary purpose is to present a fast, numerically stable, and relatively accurate kinematic model not reliant on measurement data. Experimental results on a two-tube prototype and provided for different tip loading conditions reveal maintaining a balance between adequate accuracy and reasonable running time, about 7 ms for five pieces per section, for real-time applications in the presence of external load.     

A new concept of planar self-reconfigurable modular robot for conveying microparts

Modularity and self-healing are two interesting properties that could help to design more flexible conveyors of micro-objects. In the Smart Blocks project, we propose to design a 2D modular and self-reconfigurable robot composed of centimeter-scale sliding blocks that embed their own actuators and control electronics. This article presents a proof-of-concept of the linkage and of the traveling system as well as an algorithm able to reconfigure a set of blocks from a spatial configuration to another one. Prototype blocks have been realized using electro-permanent magnets which show a good motion speed while saving power consumption during the linkage. Our reconfiguration algorithm is implemented in a simulator software showing in real-time the reconfiguration of the robot.     

Extension of the bond graph causality inversion method for fault detection and isolation

Controlled systems can be subjected to faults that may affect the performance of the system, and unable its objectives to be achieved. Fault detection and isolation algorithms are then used to study these faults. The bond graph tool can be used for modeling purposes and then its structural, and causal properties can be exploited for automatic generation of analytical redundancy relations (ARRs) through a procedure named causality inversion method, which are used for diagnosis applications. These ARRs are mathematical constraints that are used to verify the coherence between the process measurements and the system model. This paper proposes an extension of the causality inversion method by different versions of the same ARR. The goal is to increase the number of isolable faults. Moreover, structural conditions are given in order to avoid the generation of redundant ARRs. To validate the obtained structural procedure, a fault is imposed in a traction of an omnidirectional mobile robot.     

Double-level ball-riding robot balancing: From system design,modeling, controller synthesis,to performance evaluation

In this research, a new robot, double-level ball-riding robot, is introduced. The robot consists of an upper ball-riding subsystem and a lower ball-riding subsystem. The robot’s dynamics model can be considered separately in two identical planes. Euler–Lagrange equation of motion is applied in order to obtain the dynamics model. Motors are included in the robot’s model. The model is then linearized. The robot’s parameters are identified. The robot’s prototype is manufactured and assembled. Linear Quadratic Regulator with Integral (LQR + I) controller is proposed and applied in order to balance both levels of the robot. The complementary and orientation transformation are used to fuse sensors in order to obtain robot leaning angles. Balancing performance of the developed double-level ball-riding robot is evaluated by simulations and experiments. The results show efficient control performance of LQR + I controller.     

智能巡检机器人测温应用及案例

介绍了变电站智能巡检机器人软件和硬件系统,通过一次对流变端接部位发热消缺的案例,介绍了智能巡检机器人在500kV交流变电站中的应用,其中包括测温巡检任务的配置、通过实时窗口和数据库分析设备温升情况.最后比较了智能巡检机器人巡检方式较传统巡检方式的优点并阐述了意义.