Existing errors in the structure and kinematic parameters of multi-legged walking robots,the motion trajectory of robot will diverge from the ideal sports requirements in movement.Since the existing error compensation...Existing errors in the structure and kinematic parameters of multi-legged walking robots,the motion trajectory of robot will diverge from the ideal sports requirements in movement.Since the existing error compensation is usually used for control compensation of manipulator arm,the error compensation of multi-legged robots has seldom been explored.In order to reduce the kinematic error of robots,a motion error compensation method based on the feedforward for multi-legged mobile robots is proposed to improve motion precision of a mobile robot.The locus error of a robot body is measured,when robot moves along a given track.Error of driven joint variables is obtained by error calculation model in terms of the locus error of robot body.Error value is used to compensate driven joint variables and modify control model of robot,which can drive the robots following control model modified.The model of the relation between robot＇s locus errors and kinematic variables errors is set up to achieve the kinematic error compensation.On the basis of the inverse kinematics of a multi-legged walking robot,the relation between error of the motion trajectory and driven joint variables of robots is discussed.Moreover,the equation set is obtained,which expresses relation among error of driven joint variables,structure parameters and error of robot＇s locus.Take MiniQuad as an example,when the robot MiniQuad moves following beeline tread,motion error compensation is studied.The actual locus errors of the robot body are measured before and after compensation in the test.According to the test,variations of the actual coordinate value of the robot centroid in x-direction and z-direction are reduced more than one time.The kinematic errors of robot body are reduced effectively by the use of the motion error compensation method based on the feedforward.展开更多
主要分析GPS-RTK(Global Positioning System Real Time Kinematic)实时动态定位技术及其定位模式。重点讨论GPS-RTK在地质勘探测绘中的勘探网测量、控制测量、地形测量、工程点布设、勘探线剖面测量、地质工程点定位测量和物化探测量...主要分析GPS-RTK(Global Positioning System Real Time Kinematic)实时动态定位技术及其定位模式。重点讨论GPS-RTK在地质勘探测绘中的勘探网测量、控制测量、地形测量、工程点布设、勘探线剖面测量、地质工程点定位测量和物化探测量等方面的应用。最后讨论了GPS-RTK的测量误差和精度、基准站和移动站的设置以及数据链通讯和作业半径的确定。展开更多
聚焦于运动学的视阈,探讨一种基于克里格模型的机械系统优化策略。利用MSC.A D A M S建立一个简单而又具有普遍意义的多机构机械系统初始模型,修改连杆比值为[1,1.5,2]、间距为[0,5,10]cm,形成9个模型,再加密采样间隔,形成连杆比值为[1,...聚焦于运动学的视阈,探讨一种基于克里格模型的机械系统优化策略。利用MSC.A D A M S建立一个简单而又具有普遍意义的多机构机械系统初始模型,修改连杆比值为[1,1.5,2]、间距为[0,5,10]cm,形成9个模型,再加密采样间隔,形成连杆比值为[1,1.25,1.5,1.75,2]、间距为[0,2.5,5,7.5,1 0]c m的2 5个模型,计算两套模型的机械增益和加速度等运动学参数。在MATLAB下基于克里格模型算法形成空间面曲线,预测其他连杆比值和间距下的运动学参数,与真实值进行比对,讨论模型相对误差。当连杆比值为1.6,间距为6 cm时,9个模型/25个模型的相对误差为:机械增益14.32%/4.97%,加速度47.80%/20.90%;当连杆比值为1.4,间距为3 cm时,9个模型/25个模型的相对误差为:机械增益18.26%/13.06%,加速度22.98%/8.07%。随着模型规模的增大,系统各参数的预测精确度也会随之提高。应借助大数据技术等新兴产业,实时把握数据变化,补充约束条件,调节数据趋势,优化全局模型,获取最优参数。展开更多
The European XFEL, which has been constructed at DESY in Hamburg, Germany, is an X-ray-Free Electron Laser, which provides X-ray light of unprecedented properties for different experiments in physics, chemistry, biolo...The European XFEL, which has been constructed at DESY in Hamburg, Germany, is an X-ray-Free Electron Laser, which provides X-ray light of unprecedented properties for different experiments in physics, chemistry, biology and technology [1]. The XFEL is based on superconducting cavity technology, which is required to accelerate an electron beam up to 17.5 GeV. The facility is installed about 20 m underground in a 3.4 km long tunnel of 5.2 m diameter. High power RF systems are required to accelerate the beam to the required energy. Each RF station provides RF power to 4 accelerator modules with 8 superconducting cavities by a waveguide RF distribution system [2, 3]. Besides electrical and RF properties, mechanical properties are of high importance, since the waveguide distribution system and its components have to be manufactured, assembled and aligned with high precision. In order to test 100 superconducting accelerator modules within two years three test benches have been created in the AMTF （accelerator module test facility） to achieve the rate of one superconducting module per week. Each RF station of the test facility consists ofa 5 MW RF station at 1.3 GHz, 1.37 ms pulse width and 10 Hz repetition rate, with a waveguide distribution system. Each waveguide distribution supplies RF power to eight cavities, four times a pair of cavities. The distribution allows for a maximum power of 1 MW per cavity when the distribution is switched to a mode supplying power to only four cavities. A new type of 1 MW isolator and a new compact 5 MW power divider have been developed to achieve that goal. We present the waveguide distribution for this test stand and describe the performance of the different elements.展开更多
基金supported by National Natural Science Foundation of China (Grant Nos. 50675079,50875246)Program for Innovative Research Team (in Science and Technology) in University of Henan Province,China
文摘Existing errors in the structure and kinematic parameters of multi-legged walking robots,the motion trajectory of robot will diverge from the ideal sports requirements in movement.Since the existing error compensation is usually used for control compensation of manipulator arm,the error compensation of multi-legged robots has seldom been explored.In order to reduce the kinematic error of robots,a motion error compensation method based on the feedforward for multi-legged mobile robots is proposed to improve motion precision of a mobile robot.The locus error of a robot body is measured,when robot moves along a given track.Error of driven joint variables is obtained by error calculation model in terms of the locus error of robot body.Error value is used to compensate driven joint variables and modify control model of robot,which can drive the robots following control model modified.The model of the relation between robot＇s locus errors and kinematic variables errors is set up to achieve the kinematic error compensation.On the basis of the inverse kinematics of a multi-legged walking robot,the relation between error of the motion trajectory and driven joint variables of robots is discussed.Moreover,the equation set is obtained,which expresses relation among error of driven joint variables,structure parameters and error of robot＇s locus.Take MiniQuad as an example,when the robot MiniQuad moves following beeline tread,motion error compensation is studied.The actual locus errors of the robot body are measured before and after compensation in the test.According to the test,variations of the actual coordinate value of the robot centroid in x-direction and z-direction are reduced more than one time.The kinematic errors of robot body are reduced effectively by the use of the motion error compensation method based on the feedforward.
文摘主要分析GPS-RTK(Global Positioning System Real Time Kinematic)实时动态定位技术及其定位模式。重点讨论GPS-RTK在地质勘探测绘中的勘探网测量、控制测量、地形测量、工程点布设、勘探线剖面测量、地质工程点定位测量和物化探测量等方面的应用。最后讨论了GPS-RTK的测量误差和精度、基准站和移动站的设置以及数据链通讯和作业半径的确定。
文摘聚焦于运动学的视阈,探讨一种基于克里格模型的机械系统优化策略。利用MSC.A D A M S建立一个简单而又具有普遍意义的多机构机械系统初始模型,修改连杆比值为[1,1.5,2]、间距为[0,5,10]cm,形成9个模型,再加密采样间隔,形成连杆比值为[1,1.25,1.5,1.75,2]、间距为[0,2.5,5,7.5,1 0]c m的2 5个模型,计算两套模型的机械增益和加速度等运动学参数。在MATLAB下基于克里格模型算法形成空间面曲线,预测其他连杆比值和间距下的运动学参数,与真实值进行比对,讨论模型相对误差。当连杆比值为1.6,间距为6 cm时,9个模型/25个模型的相对误差为:机械增益14.32%/4.97%,加速度47.80%/20.90%;当连杆比值为1.4,间距为3 cm时,9个模型/25个模型的相对误差为:机械增益18.26%/13.06%,加速度22.98%/8.07%。随着模型规模的增大,系统各参数的预测精确度也会随之提高。应借助大数据技术等新兴产业,实时把握数据变化,补充约束条件,调节数据趋势,优化全局模型,获取最优参数。
文摘The European XFEL, which has been constructed at DESY in Hamburg, Germany, is an X-ray-Free Electron Laser, which provides X-ray light of unprecedented properties for different experiments in physics, chemistry, biology and technology [1]. The XFEL is based on superconducting cavity technology, which is required to accelerate an electron beam up to 17.5 GeV. The facility is installed about 20 m underground in a 3.4 km long tunnel of 5.2 m diameter. High power RF systems are required to accelerate the beam to the required energy. Each RF station provides RF power to 4 accelerator modules with 8 superconducting cavities by a waveguide RF distribution system [2, 3]. Besides electrical and RF properties, mechanical properties are of high importance, since the waveguide distribution system and its components have to be manufactured, assembled and aligned with high precision. In order to test 100 superconducting accelerator modules within two years three test benches have been created in the AMTF （accelerator module test facility） to achieve the rate of one superconducting module per week. Each RF station of the test facility consists ofa 5 MW RF station at 1.3 GHz, 1.37 ms pulse width and 10 Hz repetition rate, with a waveguide distribution system. Each waveguide distribution supplies RF power to eight cavities, four times a pair of cavities. The distribution allows for a maximum power of 1 MW per cavity when the distribution is switched to a mode supplying power to only four cavities. A new type of 1 MW isolator and a new compact 5 MW power divider have been developed to achieve that goal. We present the waveguide distribution for this test stand and describe the performance of the different elements.
