摇杆式履带悬架的构型推衍及其在煤矿救灾机器人上的应用

为使机器人行走机构既能被动地适应崎岖的非结构地形,又能克服台阶、沟道等规则障碍,将履带行 走机构引入摇杆式移动系统中．通过增加摆臂履带和固定关节角,推衍了多种型式的摇杆式履带悬架构型,分析了 各悬架构型的特点．结合煤矿井下非结构的地形环境与爆炸性气体环境,提出了一种采用对称的W 形履带悬架的 摇杆式履带机器人移动系统,并制作了样机．分析了该移动系统的抗倾覆、攀爬台阶、下台阶、跨越沟道等越障特 性并进行了性能试验．性能分析与样机试验表明,摇杆式履带机器人移动平台可适应复杂的非结构地形,具有良好 的越障性能,可攀爬100 mm 高的台阶,下450 mm 高的台阶,跨越260 mm 宽的沟道．     

轮腿式微型机器人系统研究

轮腿复合式机器人是在轮式机器人的基础上,通过优化轮子设计以达到快速灵活运动的一种新型的地面移动系统。该机器人主体由机架、两条主轴、齿轮减速机构、轮腿复合机构组成,由单电机驱动,控制系统相对简单。该机器人相比于普通轮式机器人具有较强的越障能力,且结构精简、体积小、重量轻。采用ADAMS对该机器人进行了运动学和动力学仿真,详细探讨了其越障能力、安装相位、轮腿结构、步态等关键问题,为其物理样机的设计、优化和控制提供了理论依据。     

可重构机器人越障运动的规划

提出一种新型的可重构机器人，该机器人在受一个驱动力矩的作用时，在不同约束下表现的输出形式不同. 利用机构这一特点，实现了机器人移动中的自主越障运动．主要针对机器人越障运动中越障高度受导轮和手臂影响的问题，提出一种借助环境同时改变手臂姿态的越障规划方法，有效地提高了越障的高度．通过试验样机验证了规划方法的有效性．     

地面移动机器人越障动力学建模与分析

对采用轮—腿—履带复合型移动机构的地面移动机器人进行了研究,首先分别描述了机器人采用腿—履带、轮—腿—履带两种方式的越障过程,进而对腿—履带复合越障过程进行了动力学建模,分析了电机驱动力矩与机器人速度及障碍物高度等之间的关系,为确定机器人的复杂环境适应能力提供理论依据.     

深海复合轮式采矿机器人越障性能研究

针对深海富钴结壳和热液硫化调查区复杂多变的底质环境特征,提出了一种兼有主被动混合越障模式的复合轮式采矿机器人.该机器人主体由4组复合轮组与铰接密封抗压型整体罐式车架组成.建立了典型越障工况下复合轮组结构的静力学模型,得到了影响其越障性能的主要结构参数,利用MATLAB工具箱对复合轮组结构参数进行优化设计,实现机器人越障性能的提高.结合深海复杂多变的底质环境特征,运用ADAMS软件对优化设计后的复合轮式机器人进行动力学建模和仿真分析.获得了机器人越障过程中的运动学特性曲线和力学特性曲线,并通过研制原理样机对其越障性能进行测试验证.结果表明,该机器人在复杂多变的深海底质环境下中具有较强的越障能力和通过稳定性.     

主从履带复合式越障机器人软土行走研究

分析了履带行走系统的力学系统原理,并采用多体动力学软件RecurDyn对主从履带复合式越障机器人虚拟样机在平地软土路面环境中的行走状态进行了仿真分析。仿真结果表明,由于样机的重心位置没有与几何中心位置重合,导致引导轮下履带沉陷量较大,而压力分配不均匀又可能导致履带局部接地,降低履带寿命,因此设计时要注意车体重心的合理分配问题。     

一种基于行星履带轮越障与混合双吸附补偿的爬壁机器人的设计与研究

针对爬壁机器人在复杂壁面工作时越障能力弱、移动迟缓和吸附力不足等问题,设计了一种基于行星履带轮越障与混合双吸附补偿的爬壁机器人,并对壁面移动和越障的性能进行研究。首先根据机器人在壁面上的运动原理,建立其力学模型,计算出沿壁面移动和越障所需的吸附力;进一步结合其受力情况,对越障过程中爬升阶段和跨越阶段的吸附力补偿模型和行...     

一种可越过管内凹形障碍的双驱动多轮移动载体的研究

本文在轮式和履带式管内行走机构的基础上，提出了一种新的管内行走机构，它利用两个电机分别驱动均布在机架上的与管内壁用弹簧力封闭的两组６个行进轮，从周向来看，３组驱动轮分别均布在３组平行四边形机构上，巧妙的把轮式和履带式管内行走机构结合在一起，使机构具有很好的越障能力．该机构紧凑，驱动效率高，工作可靠，尤其适用于管内壁有内凹障碍的管内环境．     

主从履带复合式机器人越障研究

针对机器人越障过程中的重心位置变化情况,提出一种主从履带复合式机器人越障研究方法。给出机器人样机模型,研究样机的重心变化规律和主履带系统链轮的负载扭矩变化规律,并进行越障和楼梯仿真分析。仿真结果表明,重心变化是影响越障和爬越楼梯成功与否的关键因素,样机重心位置发生变化时,履带系统链轮转矩将出现最大值。     

全方位越障移动机构研究

针对清洗壁面作业对机器人提出的特殊要求,研制了可越障轮式全方位移动机构—— -车轮组机构,该机构保证机器人在姿态保持不变的前提下,沿壁面任意方向直线移动、或 在原地旋转任意角度,同时能跨越存在于机器人运行路径中的障碍．该机构不需要传感装置 来检测障碍,不需要复杂的辅助机构来实现平面上运动和越障运动之间的转换．     

Weaver: Hexapod robot for autonomous navigation on unstructured terrain

Legged robots are an efficient alternative for navigation in challenging terrain. In this paper we describe Weaver, a six‐legged robot that is designed to perform autonomous navigation in unstructured terrain. It uses stereo vision and proprioceptive sensing based terrain perception for adaptive control while using visual‐inertial odometry for autonomous waypoint‐based navigation. Terrain perception generates a minimal representation of the traversed environment in terms of roughness and step height. This reduces the complexity of the terrain model significantly, enabling the robot to feed back information about the environment into its controller. Furthermore, we combine exteroceptive and proprioceptive sensing to enhance the terrain perception capabilities, especially in situations in which the stereo camera is not able to generate an accurate representation of the environment. The adaptation approach described also exploits the unique properties of legged robots by adapting the virtual stiffness, stride frequency, and stride height. Weaver's unique leg design with five joints per leg improves locomotion on high gradient slopes, and this novel configuration is further analyzed. Using these approaches, we present an experimental evaluation of this fully self‐contained hexapod performing autonomous navigation on a multiterrain testbed and in outdoor terrain.     

Development of a novel crawler mechanism with polymorphic locomotion

The design of a novel crawler mechanism with polymorphic locomotion is presented in this paper. The proposed mechanism, which is equipped with a planetary gear reducer, provides two kinds of outputs in different form only using one actuator. By determining the reduction ratio of two outputs in a suitable proportion, the crawler mechanism is capable of switching between two locomotion modes autonomously according to terrain. Using this property, robots equipped with the crawler mechanism can perform more efficient and adaptable locomotion or posture in irregular environments. Experimental tests showed that the developed crawler-driven module equipped with the proposed crawler mechanism cannot only move on moderately rugged terrain, but also perform a particular locomotion mode to negotiate high obstacles or adapt to different terrains without any sensors for distinguishing obstacles or any extra actuators or mechanisms for assistance.     

虚拟人行走的动作融合

研究在行走时虚拟人动作与虚拟地形之间的交互性。通过碰撞检测来确定人体在地面之上的正确位置。利用动作融合的方法,即将几个典型动作按合适的权重结合产生新的动作数据,实时地驱动虚拟人并使之对环境变化的反应满足视觉上的逼真性。融合过程中各原始动作的权重取决于沿着和垂直于人体运动方向的2个地面坡度,同时也通过对地形的几何分析来实现虚拟人对其周边地形的感知。     

六圆锥轮式月球车运动控制系统的设计研究

六圆锥轮式月球车是一种混合适应型移动机器人车，具有地形适应能力优越，越障能力强的特点。针对该款月球车，本文提出并设计了一套基于TCP/IP通讯，具有一定自主能力的遥操作运动控制系统。遥操作计算机提供月球车路径规划服务，监控月球车运行。基于实时Linux和PC104总线计算机的车载计算机运动控制系统，解析遥操作运动指令，驱动控制月球车运动。运动控制系统在六圆锥轮式月球车样机上调试，模拟现场运行验证了所设计的运动控制系统是可行的。     

综合地形环境建模与数据库实现

该文分析了现代军事仿真系统对地形环境数据的需求，采用面向对象方法构建了地形环境数据模型，根据地形环境数据模型设计了基于有向无环图结构的综合地形环境数据库，将各种仿真子系统所需的地形环境数据集成在一起，有效地解决了不同仿真应用中地形环境数据的一致性、相关性和多分辨率的问题；通过将综合地形环境数据库映射到SEDRIS表示，促进了地形环境数据的重用和共享；该文还介绍了综合地形环境数据库的数据源，分析了地形环境数据库的生成流程，最后提出了一种OpenFlight格式地形环境数据库的实现方法，节约了数据库的开发成本。     

Automated Evolutionary Design, Robustness, and Adaptation of Sidewinding Locomotion of a Simulated Snake-Like Robot

Inspired by the efficient method of locomotion of the rattlesnake Crotalus cerastes, the objective of this work is automatic design through genetic programming (GP) of the fastest possible (sidewinding) locomotion of simulated limbless, wheelless snake-like robot (Snakebot). The realism of simulation is ensured by employing the Open Dynamics Engine (ODE), which facilitates implementation of all physical forces, resulting from the actuators, joints constrains, frictions, gravity, and collisions. Reduction of the search space of the GP is achieved by representation of Snakebot as a system comprising identical morphological segments and by automatic definition of code fragments, shared among (and expressing the correlation between) the evolved dynamics of the vertical and horizontal turning angles of the actuators of Snakebot. Empirically obtained results demonstrate the emergence of sidewinding locomotion from relatively simple motion patterns of morphological segments. Robustness of the sidewinding Snakebot, which is considered to be the ability to retain its velocity when situated in an unanticipated environment, is illustrated by the ease with which Snakebot overcomes various types of obstacles such as a pile of or burial under boxes, rugged terrain, and small walls. The ability of Snakebot to adapt to partial damage by gradually improving its velocity characteristics is discussed. Discovering compensatory locomotion traits, Snakebot recovers completely from single damage and recovers a major extent of its original velocity when more significant damage is inflicted. Exploring the opportunity for automatic design and adaptation of a simulated artifact, this work could be considered as a step toward building real Snakebots, which are able to perform robustly in difficult environments.     

Nonlinear analysis of an indirectly controlled limit cycle walker

Towards controlling the frequency of limit cycle locomotion as well as adapting to rough terrain and performing specific tasks, a novel and indirect method has been recently introduced using an active wobbling mass attached to limit cycle walkers. One of the strongest advantages of the method is the easiness of its implementation, prompting its applicability to a wide variety of locomotion systems. To deeply understand the nonlinear dynamics for further enhancement of the methodology, we use a combined rimless wheel with an active wobbling mass as an example to perform nonlinear analysis in this paper. First, we introduce the simplified equation of motion and the gait frequency control method. Second, we obtain Arnold tongue, which represents region of entrained locomotion. In regions where the locomotion is not entrained, we explore chaotic and quasi-periodic gaits. To characterize bistability of two different locomotions that underlie hysteresis phenomena, basins of attraction for the two locomotions were computed. The present nonlinear analysis may help understanding the detailed mechanism of indirectly controlled limit cycle walkers.     

Design and field testing of a rover with an actively articulated suspension system in a Mars analog terrain

This study presents the electromechanical design, the control approach, and the results of a field test campaign with the hybrid wheeled‐leg rover SherpaTT. The rover ranges in the 150 kg class and features an actively articulated suspension system comprising four legs with actively driven and steered wheels at each leg’s end. Five active degrees of freedom are present in each of the legs, resulting in 20 active degrees of freedom for the complete locomotion system. The control approach is based on force measurements at each wheel mounting point and roll–pitch measurements of the rover’s main body, allowing active adaption to sloping terrain, active shifting of the center of gravity within the rover’s support polygon, active roll–pitch influencing, and body‐ground clearance control. Exteroceptive sensors such as camera or laser range finder are not required for ground adaption. A purely reactive approach is used, rendering a planning algorithm for stability control or force distribution unnecessary and thus simplifying the control efforts. The control approach was tested within a 4‐week field deployment in the desert of Utah. The results presented in this paper substantiate the feasibility of the chosen approach: The main power requirement for locomotion is from the drive system, active adaption only plays a minor role in power consumption. Active force distribution between the wheels is successful in different footprints and terrain types and is not influenced by controlling the body’s roll–pitch angle in parallel to the force control. Slope‐climbing capabilities of the system were successfully tested in slopes of up to 28° inclination, covered with loose soil and duricrust. The main contribution of this study is the experimental validation of the actively articulated suspension of SherpaTT in conjunction with a reactive control approach. Consequently, hardware and software design as well as experimentation are part of this study.     

Development of wheel-less snake robot with two distinct gaits and gait transition capability

Snake robots are mostly designed based on single mode locomotion. However, single mode gait most likely could not work effectively when the robot is subject to an unstructured working environment with different measures of terrain complexity. As a solution, mixed mode locomotion is proposed in this paper by synchronizing two types of gaits known as serpentine and wriggler gaits used for non-constricted and narrow space environments, respectively, but for straight line locomotion only. A gait transition algorithm is developed to efficiently change the gait from one to another. This study includes the investigation on kinematics analysis followed by dynamics analysis while considering related structural constraints for both gaits. The approach utilizes the speed of the serpentine gait for open area locomotion and exploits the narrow space access capability of the wriggler gait. Hence, it can increase motion flexibility in view of the fact that the robot is able to change its mode of locomotion according to the working environment.     

High-level motion planning for CPG-driven modular robots

Modular robots may become candidates for search and rescue operations or even for future space missions, as they can change their structure to adapt to terrain conditions and to better fulfill a given task. A core problem in such missions is the ability to visit distant places in rough terrain. Traditionally, the motion of modular robots is modeled using locomotion generators that can provide various gaits, e.g. crawling or walking. However, pure locomotion generation cannot ensure that desired places in a complex environment with obstacles will in fact be reached. These cases require several locomotion generators providing motion primitives that are switched using a planning process that takes the obstacles into account. In this paper, we present a novel motion planning method for modular robots equipped with elementary motion primitives. The utilization of primitives significantly reduces the complexity of the motion planning which enables plans to be created for robots of arbitrary shapes. The primitives used here do not need to cope with environmental changes, which can therefore be realized using simple locomotion generators that are scalable, i.e., the primitives can provide motion for robots with many modules. As the motion primitives are realized using locomotion generators, no reconfiguration is required and the proposed approach can thus be used even for modular robots without self-reconfiguration capabilities. The performance of the proposed algorithm has been experimentally verified in various environments, in physical simulations and also in hardware experiments.