轮腿式机器人步态生成的拓扑矩阵方法

为实现机器人在核电救灾等非结构化环境中的步态规划和自适应行走,以六足轮腿式机器人为研究对象提出基于当前地形的机器人自适应在线生成步态的规划策略,通过全局地形环境中机器人对前进方向局部地形的实时识别,确定其基本地形类型,产生相应的基本步态,动态生成机器人的步态序列。定义机器人触地状态及其列矢量表达,给出机器人步态因子的分类及其拓扑矩阵;定义基本地形及相应的基本步态,给出基本步态的拓扑矩阵;在此基础上,提出基于地形识别的步态拓扑规划策略和步态拓扑矩阵生成流程,通过矩阵递推算法实现机器人步态拓扑的动态生成。

Model-based Gait Representation via Spatial Point Reconstruction

This paper proposed a novel model-based feature representation method to characterize human walking properties for individual recognition by gait. First, a new spatial point reconstruction approach is proposed to recover the coordinates of 3D points from 2D images by the related coordinate conversion factor (CCF). The images are captured by a monocular camera. Second, the human body is represented by a connected three-stick model. Then the parameters of the body model are recovered by the method of projective geometry using the related CCF. Finally, the gait feature composed of those parameters is defined, and it is proved by experiments that those features can partially avoid the influence of viewing angles between the optical axis of the camera and walking direction of the subject.

Effects of electroacupuncture pretreatment on motor function and cerebral blood flow in MCAO model rats

Objective:To observe the effects of electroacupuncture(EA)pretreatment on motor function,cerebral blood flow,cerebral infarction volume,and vascular endothelial growth factor(VEGF)level in middle cerebral artery occlusion(MCAO)model rats.Methods:Twenty-four male Sprague-Dawley rats were randomly divided into a normal group,a model group,and an EA group,with eight rats in each group.The middle cerebral artery ischemia-reperfusion model was established by the suture-occluded method in the model group and the EA group,while not in the normal group.The EA group was pretreated with EA at bilateral Fengchi(GB20)before model preparation,once a day for 30 min each time for a total of 7 d.The changes in the CatWalk gait parameters,modified Bederson neurological deficit score,cerebral blood flow,cerebral infarction volume after ischemia,and VEGF level in the brain tissue of rats in each group were observed.Results:Compared with the normal group,the modified Bederson neurological deficit score in the model group and the EA group increased after modeling(P<0.05),and the CatWalk gait parameters(one-leg stance duration,gait cadence,and gait cycle)were all changed(P<0.05).Compared with the model group,the modified Bederson neurological deficit score in the EA group decreased(P<0.05),and the CatWalk gait parameters improved(P<0.05).Immediately after ischemia,the cerebral blood flow in the normal group was greater than that in the model group and the EA group(P<0.05);after reperfusion,the cerebral blood flow in the EA group was greater than that in the model group(P<0.05).Compared with the normal group,the cerebral infarction volume in the model group and the EA group increased(P<0.05).Compared with the model group,the cerebral infarction volume in the EA group decreased(P<0.05).The expression level of VEGF-positive cells in the rat brain tissue in the model group was higher than that in the normal group(P<0.05),and was higher in the EA group than in the model group(P<0.05).Conclusion:EA pretreatment improves the limb motor function in MCAO model rats,alleviates the symptoms of neurological deficits,promotes the recovery of cerebral blood flow,reduces the cerebral infarction area after MCAO modeling,and increases the VEGF expression in the brain tissue.