共查询到19条相似文献,搜索用时 46 毫秒
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很多国内外的学者都对机械臂的工作空间进行了研究,提出了很多不同的方法。蒙特卡洛算法是一种较为广泛的方法。这种算法产生的点云式工作空间表示,很难应用于类似于路径规划这样的任务。针对这种问题,提出了工作空间限制下的路径规划方法。首先对环境空间进行离散化,使用机械臂逆运动学确定工作空间。这样得到的工作空间可以用小正方体及其顶点的数据结构表示,非常容易应用改造后的快速搜索随机树(RRT)算法。最后,与蒙特卡洛算法和标准RRT算法的对比实验证明了所提出方法的有效性。 相似文献
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串联机械臂运动控制系统设计 总被引:1,自引:0,他引:1
由于加工装配的累积误差,驱动控制,机械臂的柔性变形以及实际工作环境中振动等因素的干扰,导致无法准确获取机械臂的运动学模型和动力学模型,导致机械臂实际的运动性能与期望的高精度运动性能相比出现较大的差距。针对上述问题,文中通过研究串联机械臂轨迹优化算法,设计了一套简单且实时性的机械臂控制变量补偿系统,以减少甚至消除机械臂的运动学误差。这一技术的实现,将对提高装备制造业中机械臂运动精度关键技术的发展起到推动作用。 相似文献
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在空间站机械臂中,双目视觉系统作为其重要组成部分,能够引导机械臂自主完成对目标的定位和捕获。内外参标定技术是双目相机高精度获取合作目标位置、方向等运动信息进而进行三维重建的首要前提和重要保障。文中提出了一种基于光束法平差算法的双目视觉系统内外参标定技术,采用三维靶标场作为标定目标,并将高精度测角设备经纬仪作为精测基准,通过坐标转换解算分步得到相机的内、外参数。实验表明,该方法标定的相机内参重投影误差小于0.5个像元,外参测试误差为±0.19 mm,有较高的测试精度和鲁棒性,为机械臂实施视觉闭环自主捕获合作目标提供可靠依据。 相似文献
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针对欠驱动柔性机械臂建模、控制困难的问题,文中采用在第一关节安装轻质弹簧的方法来表示机械臂的柔性,从而得到柔性臂的简化模型。将其应用到两连杆欠驱动柔性机械臂中,建立欠驱动柔性机械臂的系统模型,并利用拉格朗日函数法,对该系统进行动力学建模。同时通过构造基于系统能量和驱动杆状态的李雅普诺夫函数,设计该欠驱动柔性机械臂系统的控制律。最后,使用Matlab对该系统及所设计的控制律进行数值仿真。仿真结果表明,所构建的动力学模型以及设计的控制规则具有良好的有效性,且同时具备响应速度快、控制输入小的优点。 相似文献
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为了解决传统分拣过程中效率低下的问题,文中采用LabVIEW设计了机械臂分拣系统,通过将不同位置、形状的目标进行分拣,并在PC端获得对目标的统计信息,利用LabVIEW读取目标信息数据,通过判断选出合适的数据组,并将其转化为串口通信指令发送给机械臂控制板,解析指令后按步骤完成分拣操作.实验结论显示,系统上位机可同步显示... 相似文献
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《Electron Devices, IEEE Transactions on》1970,17(10):907-915
In the first part of the paper the importance of the microwave circuit parameters on the attainment of LSA oscillation in ideal uniform devices is investigated. It is shown to be desirable for the circuit to have high-dynamic impedance. In consequence stray capacity at the device, due to the device configuration or to the mounting arrangement, is to be avoided. The existence of a capacityC in parallel with the cold-device capacity C0 effectively raises the lower limit for LSA operation ton/f > 2 times 10^{4}[(C+C_{0})/C_{0}] . In the second part of the paper devices with typical doping and mobility profiles are considered to operate in circuits with low-dynamic impedance as well as in circuits with high-dynamic impedance. The results presented show that the LSA operating efficiency can be very sensitive to certain inhomogeneities, notably doping ramps of order 12½ percent and high-resistivity regions at the cathode contact. The efficiency degradation is, however, very dependent on the circuit in which the device is operating. Finally it is shown that the efficiency of a CW device may be raised by several percent in some cases by compensating for the mobility profile with a suitable doping gradient. 相似文献
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《现代电子技术》2017,(18)
机械手臂的诞生具有解放生产力的现实意义,机械手臂转角控制格外重要,因而,采用PID控制设计机械手臂转角自动控制器。所设计的自动控制器具有四个自由度,由PLC、步进电机和SH-215B步进电机驱动器组成,步进电机驱动器从PLC中接收转角命令,转角命令中蕴含的定位信息由步进电机中BCE58K20增量式光电编码器给出,进而控制机械手臂转角动作。PLC在使用普通PID控制下,积分控制环极易超调,采用模糊技术将普通PID控制模糊化,借助分离技术降低积分超调对机械手臂动作的影响,提出模糊分离PID控制。实验结果表明,与采用其他控制策略的自动控制器相比,采用模糊分离PID控制的自动控制器自由度更加灵活。 相似文献
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In this paper, the impact on non-planarization index by the down force and rotational speed during a SiO2 or Cu CMP process was investigated. Since the magnitudes of down force and rotational speed have limits, we choose the dynamic programming approach because of its ability to achieve constrained optimization by the down force and rotational speed. The duration and the amount of input were computed based on the chemical mechanical polishing model by Luo and Dornfeld [J. Luo, D.A. Dornfeld, IEEE Trans. Semiconduct. Manufact. 14(2) (2001) 112-132.] when the other parameters were fixed. Experiments done for blanket wafers based on dynamic programming operation and conventional constant removal rate operation was compared with each other. The non-planarization index could be improved consistently by dynamic programming operation versus constant removal rate operation. The improvement ranges from 2% to 39% improvement over the base recipe of constant removal rate in all experiments as shown in Table 3 and Table 6. The thickness removal error is consistently smaller by constant removal rate operation versus dynamic programming operation in all experiments as shown in Table 3 and Table 6. To get the best performance of both planarization and thickness removal, it is recommended that planarization step and overpolish step in SiO2 and Cu CMP should use different mode of operation, i.e., dynamic programming operation during planarization step for minimizing non-planarization index and constant removal rate operation during overpolish step for minimizing thickness removal error. The incremental time calculation for eliminating thickness removal error during overpolish step can be done using the thickness error and removal rate derived from Luos’ removal rate model based on constant wafer pressure and platen speed at the end of planarization step.Our contribution is a new approach for CMP. Standard CMP uses constant removal rate operation in both planarization step and overpolish step. Our new approach uses dynamic programming operation during planarization step and constant removal rate operation during overpolish step. 相似文献
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设计实现一种新的机械手臂康复系统。利用Kinect体感器获取人体右肩、右肘和右腕3个关节的三维坐标,计算得出所需控制参数。建立体感器与机械手臂之间通信机制,通过数据反馈调整所需控制参数。实现多自由度同时协调运动的康复型机械手臂控制方法。实验表明,该系统控制下的机械手臂能够平滑无明显停顿感地模仿人类手臂的自然动作,提高患者使用时的舒适度,增强康复效果。 相似文献