自由漂浮空间机器人捕获翻滚目标的力-位-型融合控制方法

翻滚目标捕获过程中,空间机器人的运动会对基座产生扰动、接触过程的冲击碰撞容易产生安全风险。因此,为了在捕获翻滚目标的同时抑制空间机械臂对基座的扰动和对目标的碰撞冲击,提出一种自由漂浮空间机器人力-位-型融合控制方法。首先将自由漂浮空间机器人的非完整冗余性、运动冗余性表征为型空间,构建由末端位姿、型状态组合的广义状态空间并建立系统的运动学和动力学模型;通过优化基座与机械臂的位-型及零空间运动,减小机械臂抓捕运动在基座产生的扰动;通过优化基座、机械臂与翻滚目标的相对位-型,减小碰撞冲击力在基座产生的姿态扰动。给定最优位-型及末端操作力,基于阻抗控制原理及零空间投影策略,实现多优先级力-位-型融合控制。最后,开展了空间机器人捕获翻滚目标的典型任务仿真,结果表明通过力-位-型融合优化与控制方法可以有效减小空间机器人捕获过程产生的基座扰动。

大学生优秀党员成长轨迹的实践路径分析

当代大学生党员是高校学生群体中的骨干力量,大学生优秀党员的成长遵循着组织特有的培养程序,有其固有的轨迹。探索大学生优秀党员成长的轨迹,对于做好高校的人才培养工作具有重要作用,从实践起点、实践路径和实践目标三个阶段来探索大学生优秀党员成长的轨迹。

刚柔混合双臂空间机器人抓持-操作协同规划

针对狭小空间内的在轨维修操作,提出了一种基于受限空间可操作度优化的刚柔混合双臂协调轨迹规划方法。根据绳驱柔性臂的结构特性对其进行运动学等效,并完成了刚柔混合双臂等效运动学模型的建立,得到基座漂浮状态下的广义雅可比矩阵以及对应的零空间投影矩阵。以任务操作方向上的可操作度为优化指标,通过零空间投影矩阵建立优化函数方程;同时基于分解运动速度控制,通过广义雅可比矩阵实现末端速度空间到关节速度空间的映射,实现了混合双臂抓持-操作目标的同步运动控制。最后,开发了基于联合仿真软件的混合双臂联合仿真系统,仿真结果验证了上述方法的有效性。

CALIBRATION OF A 6-DOF SPACE ROBOT USING GENETIC ALGORITHM

The kinematic error model of a 6-DOF space robot is deduced, and the cost function of kinematic parameter identification is built. With the aid of the genetic algorithm （GA） that has the powerful global adaptive probabilistic search ability, 24 parameters of the robot are identified through simulation, which makes the pose （position and orientation） accuracy of the robot a great improvement. In the process of the calibration, stochastic measurement noises are considered. Lastly, generalization of the identified kinematic parameters in the whole workspace of the robot is discussed. The simulation results show that calibrating the robot with GA is very stable and not sensitive to measurement noise. Moreover, even if the robot＇s kinematic parameters are relative, GA still has strong search ability to find the optimum solution.

仿生扑翼飞行机器人自主导航系统研究进展

仿生扑翼飞行机器人模仿自然界鸟类和昆虫等生物的飞行方式,具有安全性强、迷惑性好等优点,在灾害救援、反恐防暴等方面具有极其重要的应用前景。为实现其在未知复杂环境下的自主飞行并执行探测任务,需研制一套集感知建图、规划避障与飞控制导等功能模块为一体的导航系统。本文首先对扑翼飞行机器人的导航系统进行了概述,按照翼展大小将扑翼飞行机器人分为微小型和大中型两类,其次对比分析了国内外在微小型、大中型扑翼飞行机器人导航系统方面的主要研究进展。接着对自主导航系统所涉及到的感知定位与建图、运动规划与避障、轨迹跟踪与飞控制导等关键技术进行了分析总结,指出其局限性及亟待解决的问题。最后,对未来的研究趋势进行了展望,包括提升机载嵌入式计算能力、多模态信息融合、面向多模态飞行的流场感知、仿生视觉系统研究、群体感知与编队控制等热点方向。

Feedback Attitude Sliding Mode Regulation Control of Spacecraft Using Arm Motion

The problem of spacecraft attitude regulation based on the reaction of arm motion has attracted extensive attentions from both engineering and academic fields.Most of the solutions of the manipulator’s motion tracking problem just achieve asymptotical stabilization performance,so that these controllers cannot realize precise attitude regulation because of the existence of non-holonomic constraints.Thus,sliding mode control algorithms are adopted to stabilize the tracking error with zero transient process.Due to the switching effects of the variable structure controller,once the tracking error reaches the designed hyper-plane,it will be restricted to this plane permanently even with the existence of external disturbances.Thus,precise attitude regulation can be achieved.Furthermore,taking the non-zero initial tracking errors and chattering phenomenon into consideration,saturation functions are used to replace sign functions to smooth the control torques.The relations between the upper bounds of tracking errors and the controller parameters are derived to reveal physical characteristic of the controller.Mathematical models of free-floating space manipulator are established and simulations are conducted in the end.The results show that the spacecraft’s attitude can be regulated to the position as desired by using the proposed algorithm,the steady state error is 0.000 2 rad.In addition,the joint tracking trajectory is smooth,the joint tracking errors converges to zero quickly with a satisfactory continuous joint control input.The proposed research provides a feasible solution for spacecraft attitude regulation by using arm motion,and improves the precision of the spacecraft attitude regulation.

基于操控技能映射的扑翼机器人自主飞行控制

仿生扑翼飞行机器人气动特性复杂,难以精确建模,为自主飞行控制带来了巨大挑战。基于此,提出了一种模拟飞手操控行为的扑翼飞行机器人自主飞行控制方法,将飞手操控技能映射至控制算法中,不依赖于精确动力学模型即可实现不同场景下的自主飞行控制。首先,对起飞、巡航、机动、降落等不同阶段开展大量的飞手实际操控实验,根据实验结果建立了飞手操控行为与扑翼飞行机器人飞行状态的映射关系。进而,将飞手对机器人的状态辨别和操控方式转换为操控技能库,并设计了指点飞行、直线轨迹跟踪、绕圆飞行等机动飞行的控制方法,以及在受限空间自主飞行的智能避障方法。结合传感器数据融合结果调用技能库所对应的控制决策,通过模拟飞手控制行为生成控制量,保障了飞行的安全性。最后,研制了飞行控制器,并与仿生扑翼飞行机器人集成后开展了户外飞行实验,对所提出的方法进行了验证。结果表明,模拟飞手操控行为的控制方法可实现可靠飞行,且灵活性及可扩展性强。

A geometric method based on space arc for pose-configuration simultaneous planning of segmented hyper-redundant manipulators

A segmented hyper-redundant manipulator can perform complicated operation tasks in a confined space due to its high flexibility and dexterity. However, the trajectory planning in a narrow space and obstacles environment is very challenging for the manipulator. In this paper, we propose a geometry method to simultaneously plan the end-effector pose and manipulator’s configuration. Firstly, the geometries of each segment are described by an inscribed arc(IA) and a circumscribed arc(CA). Then,the whole kinematics chain is considered as an inscribed curve(IC) or a circumscribed curve(CC) which are composed of multiple IAs or CAs. Furthermore, the IC and CC of the manipulator are divided into multiple spatial single-arc and double-arc groups according to requirements. The pose-configuration simultaneous planning is realized by the spatial single-arc/double-arc modeling and joints angles solving. By numerical iteration, the spatial arcs’ parameters are determined according to desired pose and boundary condition of obstacle avoidance. The angles of joints are analytically solved when the above parameters are known. Finally, a narrow space detection task is simulated and experimented respectively. The results verify the proposed method.

Autonomous flight control with different strategies applied during the complete flight cycle for flapping-wing flying robots

Flapping-wing flying robots(FWFRs),especially large-scale robots,have unique advantages in flight efficiency,load capacity,and bionic hiding.Therefore,they have significant potential in environmental detection,disaster rescue,and anti-terrorism explosion monitoring.However,at present,most FWFRs are operated manually.Some have a certain autonomous ability limited to the cruise stage but not the complete flight cycle.These factors make an FWFR unable to give full play to the advantages of flapping-wing flight to perform autonomous flight tasks.This paper proposed an autonomous flight control method for FWFRs covering the complete process,including the takeoff,cruise,and landing stages.First,the flight characteristics of the mechanical structure of the robot are analyzed.Then,dedicated control strategies are designed following the different control requirements of the defined stages.Furthermore,a hybrid control law is presented by combining different control strategies and objectives.Finally,the proposed method and system are validated through outdoor flight experiments of the HIT-Hawk with a wingspan of 2.3 m,in which the control algorithm is integrated with an onboard embedded controller.The experimental results show that this robot can fly autonomously during the complete flight cycle.The mean value and root mean square(RMS)of the control error are less than 0.8409 and 3.054 m,respectively,when it flies around a circle in an annular area with a radius of 25 m and a width of 10 m.