串联机器人加工系统关节刚度的高精度辨识方法

提出一种串联机器人加工系统关节刚度的高精度辨识方法.首先,基于雅克比矩阵的Frobenius范数,得到串联机器人加工系统的灵巧性,并确定工作空间内可达姿态的灵巧性数值分布情况.然后,分别选取4组不同等级灵巧性的姿态进行关节刚度辨识实验,并计算出相应姿态下的关节刚度.最后,对辨识出的4组关节刚度的末端变形计算值与测量值进行相对误差分析.结果表明:随着灵巧性的增大,机器人关节刚度辨识的准确性越高;相较于灵巧性较小的姿态,灵巧性较大的姿态的末端变形计算值与测量值的相对误差可降低20%~50%.     

移动机器人滑模路径的跟踪控制

针对移动机器人的路径跟踪问题,基于反演思想设计了滑模路径跟踪控制器,并利用低通滤波器有效地减弱了控制过程中的干扰.由于该控制器的动态性能不理想,因此采用有界输入的方法对其进行控制律的改进,并简化了控制器的设计.仿真结果表明,改进后的滑模控制器跟踪效果良好,动态响应快,且保证了移动机器人的全局渐近稳定路径跟踪控制.     

柑橘果园机器人仿生眼的目标跟踪与定位系统

针对传统柑橘园林机器人云台视野范围小、定位精度低等问题,在仿生眼平台上,提出一种基于连续自适应均值偏移(CAM shift)算法和变结构PID控制器相结合的目标跟踪方法。具体包括效仿人类眼颈的结构特点,设计一个4自由度的仿生眼视觉平台;建立仿生眼的成像模型,提出一种相机外参数自适应标定方法,以解决仿生眼平台外参数会随着相机位姿改变而不断变化的问题;提出基于CAM shift的仿生眼目标跟踪算法,成功实现了对于目标的持续跟踪;为提高仿生眼系统在饱和非线性特性下的动态响应性能,提出采用基于抗饱和(Anti-windup)的变结构自适应PID控制器来设计仿生眼控制系统。以柑橘为研究对象,在设计的仿生眼平台上开展试验。结果表明,本文方法左眼平均中心位置像素误差(CPE)为7.2,右眼CPE6.1,均小于设计所要求的CPE10,且每帧图像处理过程小于0.1s。系统能满足实际应用,具有较高的鲁棒性和准确性。     

手术制孔机器人研究进展

传统手术制孔是由医生操作辅助制孔装置,对医生的专业技能与经验积累有很高的要求,同时制孔精度与手术安全性不高.自动制孔技术可以保证手术制孔的安全与精度,缩短手术时间.骨骼制孔过程中,骨骼与钻头的连续摩擦会引起热积累,当温度超过临界值时会导致骨骼发生热坏死.如果钻头超过预设深度就会对骨头周围血管、肌肉及神经造成严重损伤.热积累控制和突破控制研究是保证手术制孔机器人安全操作的关键.研究表明,骨骼发生热坏死的临界温度为47℃,旋转超声骨骼制孔结合金刚石磨粒刀具的方式可以将制孔温度控制在40 ℃.骨骼制孔突破控制主要通过力/力矩、位置、声发射功率谱检测和神经网络分类等方法实现,其中通过力/力矩检测实现突破控制的效果最佳.在骨骼制孔过程中,还会产生钻削振动,因此对手术制孔机器人常用的振动控制方式进行了分析研究,并总结了其他有待进一步解决的问题并展望了未来的研究方向.     

机器人作战平台操控终端系统的设计

针对机器人作战平台应用环境和作战特点,设计了机器人作战平台操控终端系统.应用单片机STC89C52RC和ADC0809构建控制指令采集系统的方法,以查询的方式将采集的控制指令通过串口以预定的通信协议传给单板机,并通过无线通信网络传给远端的机器人以实现其监控;同时操控终端系统接收机器人作战平台传感器采集的信息并显示.实验结果表明,利用操控终端操作者可对机器人作战平台进行实时、高效的操控和监视.     

Dynamic characteristics of an intestine capsule robot with variable diameter

This paper proposes an intestine capsule robot with variable diameter. It is driven by external rotating magnetic field and has the function of automatic radial clearance compensation. An external magnetic field generating device and a capsule robot with variable diameter are developed. Radial dynamic balance equation and kinematics equation of the capsule robot traveling inside flexible elasto-wall environment are established, and dynamic characteristics of the capsule robot inside flexible elasto-wall pipe and rigid wall pipe environments are analyzed and compared. Simulations and experiment results show that its dynamic characteristics in both pipes are almost the same. Under the action of radial clearance compensation, fluid dynamic pressure around outer surface of the capsule robot and its propulsion, as well as its adaptability to diameter change range, are significantly improved. Its propulsion and moving speed are controlled by adjusting rotating angular speed of the rotating magnetic field. This innovative capsule robot with radial clearance compensation has a promising prospect for inside intricate gastrointestinal (GI) tract in non-invasive therapy applications.     

机器人路径规划的一种改进蚁群算法

介绍了一种静态环境下机器人路径规划的改进蚁群算法。该算法使用栅格法对机器人的工作空间进行建模。搜索过程采用了蚂蚁落入陷阱回退策略和蚂蚁相遇策略,从而避免了遇到陷阱时形成的路径死锁情况,同时也提高了最优路径的搜索效率。仿真研究表明,该算法能明显改善路径规划性能,并且算法简单有效。     

一种新型自重构机器人模块的对接机构设计

提出了一种新颖的晶格式空间自重构机器人模块,并进行了模块的三维结构设计.详细阐述了该自重构机器人模块基于销槽楔合、雌雄同体的对接机构设计方法,分析了系统的运动精度并给出了相应的误差控制方案.设计了静态及动态的2组实物实验,从不同工作条件验证了该对接机构能够快速、可靠地实现对接过程,对接耗时约为2 s,对接完成后的机械连接强度可超过50 N的轴向拉伸负载,较好地完成了机器人模块的自重构任务.     

The obstacle crossing ability analysis and improvement of the cable inspection robot

In this paper, the climbing obstacle capability of the previous special cable inspection robot (Model Number: XS1T-1) is analyzed. Static equations are established to analyze the relationships between the external forces and the maximum height of an obstacle. Parameters affecting the obstacle crossing ability are obtained. According to the analysis results, an innovated small volume, simple structure and light weight climbing mechanism is proposed (Model Number: XS1T-2). A simplified kinematics model of the mechanism is established. With two powered wheels, the obstacle crossing ability of the XS1T-2 is improved apparently. For the robot moving without deflection, the relationships of two powered input torques are deduced. The comparison of the simulation results clearly shows that the climbing ability of XS1T-2 is obviously improved, and it can meet the demands of inspection.     

A control structure for the autonomous locomotion on rough terrain with a hexapod robot

A motion control structure used for autonomous walking on uneven terrain with a hexapod biomimetic robot is proposed based on function-behavior-integration.In the gait planning level, a set of local rules operating between adjacent legs were put forward and the theory of finite state machine was employed to model them; further, a distributed network of local rules was constructed to adaptively adjust the fluctuation of inter-leg phase sequence.While in the leg-end trajectory planning level, combined polynomial curve was adopted to generate foot trajectory, which could realize real-time control of robot posture and accommodation to terrain conditions.In the simulation experiments, adaptive regulation of inter-leg phase sequence, omnidirectional locomotion and ground accommodation were realized, moreover, statically stable free gait was obtained simultaneously, which provided hexapod robot with the capability of walking on slightly irregular terrain reliably and expeditiously.