基于球面四杆机构调控滚子偏置角的锥式Mecanum轮

Mecanum轮作为一种全方位行走轮在多领域广泛应用,针对Mecanum运动系统受限于平整光滑路面,提出一种拓展到类“V”形路面行走的新型变锥角Mecanum轮,该轮每个滚子分别对应安装于阵列球面四杆机构上,其周向阵列球面四杆机构具有公共输入轴,以同步驱动安装于连杆上对应的Mecanum轮滚子,实现滚子轴线偏置角变化,达到Mecanum轮锥角变化,增加Mecanum轮运动系统对“V”形地面行走适应性;通过建立球面四杆机构运动学模型,求解出球面四杆机构的输入输出方程,得到公共轴输入转动角度与滚子偏置角间映射关系;基于包络原理近似求得Meca num轮可控锥角所对应的路面坡度。

月面居住舱可折叠轮式移动机构方案设想

为实现月球居住舱的移动并能够充分利用空间,根据月球表面的作业环境分析了居住舱的任务,提出了一种能够提高探测能力的月面居住舱移动机构设计方案,介绍了该移动机构在月球折叠着陆、展开移动、锁定停放及折叠起飞返回4种工作模式,总结了月面机构设计、着陆缓冲、驱动控制、能源动力以及自主维护等方面的关键技术与难题。

Gait Planning for a Quadruped Robot with One Faulty Actuator

Fault tolerance is essential for quadruped robots when they work in remote areas or hazardous environments. Many fault-tolerant gaits planning method proposed in the past decade constrained more degrees of freedom（DOFs） of a robot than necessary. Thus a novel method to realize the fault-tolerant walking is proposed. The mobility of the robot is analyzed first by using the screw theory. The result shows that the translation of the center of body（CoB） can be kept with one faulty actuator if the rotations of the body are controlled. Thus the DOFs of the robot body are divided into two parts： the translation of the CoB and the rotation of the body. The kinematic model of the whole robot is built, the algorithm is developed to actively control the body orientations at the velocity level so that the planned CoB trajectory can be realized in spite of the constraint of the faulty actuator. This gait has a similar generation sequence with the normal gait and can be applied to the robot at any position. Simulations and experiments of the fault-tolerant gait with one faulty actuator are carried out. The CoB errors and the body rotation angles are measured. Comparing to the traditional fault-tolerant gait they can be reduced by at least 50%. A fault-tolerant gait planning algorithm is presented, which not only realizes the walking of a quadruped robot with a faulty actuator, but also efficiently improves the walking performances by taking full advantage of the remaining operational actuators according to the results of the simulations and experiments.

Human-Tracking Strategies for a Six-legged Rescue Robot Based on Distance and View

Human tracking is an important issue for intelligent robotic control and can be used in many scenarios, such as robotic services and human-robot cooperation. Most of current human-tracking methods are targeted for mobile/tracked robots, but few of them can be used for legged robots. Two novel human-tracking strategies, view priority strategy and distance priority strategy, are proposed specially for legged robots, which enable them to track humans in various complex terrains. View priority strategy focuses on keeping humans in its view angle arrange with priority, while its counterpart, distance priority strategy, focuses on keeping human at a reasonable distance with priority. To evaluate these strategies, two indexes（average and minimum tracking capability） are defined. With the help of these indexes, the view priority strategy shows advantages compared with distance priority strategy. The optimization is done in terms of these indexes, which let the robot has maximum tracking capability. The simulation results show that the robot can track humans with different curves like square, circular, sine and screw paths. Two novel control strategies are proposed which specially concerning legged robot characteristics to solve human tracking problems more efficiently in rescue circumstances.

剪叉可展机构腿的步行机设计及性能分析

从可展开的剪叉状连杆单元入手,利用其运动特性进行了步行机腿的构型设计,并就可展单元结构进行了物理性能分析,确定了步行机可展单元腿的基本构型;进行了可展机构腿的运动学分析,采用矢量法求解了腿部运动学正解,并给出了正解的解析表达式;同时与一般单开链两自由度连杆机构腿对比进行了承载能力分析,说明可展机构腿在行走作业时具有良好的克服非结构化路面的潜能以及良好的步态遍历性;根据运动学给出了腿部的工作空间,分析了工作空间内的力学分布情况;以四足步行机为例,进行了腿的尺度设计,给出了一种可展机构腿的整机实例。

冬奥冰壶六足机器人研究

冰壶六足机器人是北京2022年冬奥会组委会需求的唯一进入冬奥会赛场的机器人。开发该机器人的目的是借助北京冬奥会展示我国机器人的自主创新能力和水平。我们重视独特设计创意,通过模仿冰壶运动员投掷冰壶的“行为特征”来设计和开发冰壶六足机器人。冰壶六足机器人设计面临多项挑战,要解决模仿人投掷冰壶行为的六足机器人的构形综合、投掷冰壶任务链与机器人行为链关联特征建立、机器人击打冰壶行为规划等问题。研制的冰壶六足机器人在北京2022年冬奥会冰立方冰壶赛场上顺利完成击打冰壶表演。

六足机器人半被动行走步态控制方法及其动力学仿真

为降低六足机器人稳定行走能耗,提出了一种六足机器人半被动行走步态控制方法。首先,通过分析半被动行走步态的混合动力学模型,并考虑不平整地形下六足机器人多条摆动腿落地差异,提出具有摆动腿提前触地调整策略的六足机器人半被动行走控制方法。其次,基于胞映射原理分析步态稳定性并寻找初始值吸引域作为仿真起始条件。最后,在UG/Simulink联合仿真环境下对机器人低能耗半被动行走能力进行验证。仿真结果显示,六足机器人半被动行走步态的传输能耗远低于主动控制机器人的能耗,且具备台阶等不平整地形适应能力,对六足机器人复杂环境下远距离长时间作业有重要意义。

基于足地接触特性辨识的六足机器人自适应阻抗控制

为提高足式机器人在未知地面环境中运动适应能力,提出了一种基于足地接触特性辨识的模糊自适应阻抗控制算法首先,针对六足机器人提出一种足地接触特性辨识方法为降低六足机器人行走时足地之间的冲击力,提出了一种六足机器人沿腿长方向基于足地接触参数的模糊自适应阻抗控制器基于六足机器人在不平坦地面行走时的足地接触状态,建立机器人步态控制状态机及行走控制框架通过六足机器人仿真模型,对足地接触特性辨识方法、模糊自适应阻抗控制器以及机器人行走控制框架进行仿真验证,并应用到“青骓”六足机器人样机进行实验验证。

空间对接半物理仿真系统失真的内模控制方法

在空间对接半物理仿真系统中,运动模拟器的响应延迟会导致系统产生发散失真现象,甚至导致机械部件损伤。为解决该系统失真问题,提出了基于内模控制的系统失真补偿方法。本文分析了系统的失真原理,将内模控制方法应用于该系统,并等效为内模PID控制(IMC-PID)模型。利用模型辨识方法,采用二阶模型拟合高阶模型。对于空间对接半物理仿真系统,进行单自由度碰撞数字仿真与实验,验证该方法的可行性,为空间对接半物理仿真系统的失真问题提供了新的解决方法。

基于双光束激光干涉仪的微动平台六维位姿测量建模与误差分析

为解决微动平台末端六维位姿的高精度测量问题,研究基于双光束激光干涉仪的位姿测量方法。利用空间正交布置的三台双光束激光干涉仪,测量微动平台上3个待测平面的线位移和角位移,通过测量系统的数学模型计算得到微动平台的六维位姿。建立了测量系统的数学模型,设计了高精度的简化求解方法,分析了各系统误差对测量结果精度的影响,为建立微动平台高精度位姿测量系统提供了理论基础,并成功应用于实际微动平台的标定。

Obstacle avoidance for a hexapod robot in unknown environment

Obstacle avoidance is quite an important issue in the field of legged robotic applications, such as rescuing and detecting in complicated environment. Most related researchers focused on the legged robot’s gait generation after ssuming that obstacles have been detected and the walking path has been given. In this paper we propose and validate a novel obstacle avoidance framework for a six-legged walking robot Hexapod-III in unknown environment. Throughout the paper we highlight three themes: (1) The terrain map modeling and the obstacle detection; (2) the obstacle avoidance path planning method; (3) motion planning for the legged robot. Concretely, a novel geometric feature grid map (GFGM) is proposed to describe the terrain. Based on the GFGM, the obstacle detection algorithm is presented. Then the concepts of virtual obstacles and safe conversion pose are introduced. Virtual obstacles restrict the robot to walk on the detection terrain. A safe path based on Bezier curves, passing through safe conversion poses, is obtained by minimizing a penalty function taking into account the path length subjected to obstacle avoidance. Thirdly, motion planning for the legged robot to walk along the generated path is discussed in detail. At last, we apply the proposed framework to the Hexapod-III robot. The experimental result shows that our methodology allows the robot to walk safely without encountering with any obstacles in unknown environment.

Hardware-in-the-loop simulation for the contact dynamic process of flying objects in space

在地面上的一个严肃环境，自从人首先由飞目标探索了空间，在空间的零严肃的环境的二个飞的目标的接触过程的模拟是一个挑战性的问题。Hardware-in-the-loop (HIL ) 模拟是一个重要、有效的方法在空间测试真实停靠机制的可用性，可靠性，和安全。为 HIL 模拟系统有四个主要问题：能够高频率反应，高运动精确，高速度，和快速的加速的模拟器的设计；为模拟失真的赔偿；为 HIL 模拟进程的一个控制模型的设计；并且试验性的确认。这里，我们与 6-DOF 3-3 建议一个新奇 HIL 模拟器系统垂直平行机制和 3-DOF 3-PRS 平行机制；发现模拟失真的原则；为模拟器的力量测量系统，动态反应，和结构的动力学介绍失真赔偿模型；并且为 HIL 模拟过程提供一个控制模型。二种实验在被动未受潮的有弹性的杆和停靠机制上被执行测试他们的表演并且验证 HIL 模拟器的有效性和可用性。在这份报纸建议的 HIL 模拟系统为开发停靠的空格是有用的， berthing， refueling，修理，升级，搬运，并且 rescuing 技术。