双足机器人的鲁棒自适应复合控制器设计

针对复杂机器人对象,充分考虑系统的各种不确定因素,在不确定保守上界己知情况下,设计了全局稳定的鲁棒自适应复合控制器。控制器设计在确保高品质控制的同时,避免或减少了参数漂移、保守鲁棒增益及控制系统抖振等问题,从理论与实际的角度提高了控制器的鲁棒性和实用性。仿真实验验证了提出优化方法的有效性,而且机器人能在一定范围外力的干扰下回复稳定姿态步行。     

伸缩腿双足机器人半被动行走控制研究

研究半被动伸缩腿双足机器人行走控制和周期解的全局稳定性问题.使用杆长可变的倒立摆机器人模型,以支撑腿的伸缩作为行走动力源,采用庞加莱映射方法分析了双足机器人行走的不动点及其稳定性.当脚与地面冲击时,假设两腿间的夹角保持为常数,设计了腿伸缩长度的支撑腿角度反馈控制率.证明了伸缩腿双足机器人行走过程不动点的全局稳定性.仿真结果表明,本文提出的腿伸缩长度反馈控制可以实现伸缩腿双足机器人在水平面上的稳定行走,并且周期步态对执行器干扰和支撑腿初始角速度干扰具有鲁棒性.     

水下仿生机器鱼的研究进展II—小型实验机器鱼的研制

本文介绍了自行研制的一条小型实验机器鱼 .该机器鱼作为研究仿生机器鱼的流体力学性能的实验平台 ,具有刚性头部、5关节的柔性身体和月牙形尾鳍 ,采用无线遥控 .机器鱼体长 890 mm,水中最大速度为 2 0 cm/s,最大转弯角速度为 12 0°/ s,最小转弯半径为 4 0 cm.综合性能测试实验和 C形运动控制实验表明 ,该机器鱼具有较好的游动性能和较高的机动性能     

基于二阶倒立摆的人体运动合成

为了合成物理真实、实时可控的人体运动,提出了一种基于二阶倒立摆的人体运动合成方法.方法分三步实现:首先将人体运动状态映射为一个二阶倒立摆模型;然后根据步态控制参数与环境约束,对二阶倒立摆进行运动规划;最后基于二阶倒立摆的运动,根据人体运动规律与高层用户需求,优化计算关节力矩,合成人体全身运动.利用文中方法,通过设置不同的参数,如步幅、步频等,能够实时控制人体运动,生成物理真实的人体运动.与现有的低维模型方法相比,该方法能够生成更加自然真实的人体下肢运动.该文合成方法既不需要使用运动捕获数据,也无需耗时的离线优化.     

Path Planning for a Statically Stable Biped Robot Using PRM and Reinforcement Learning

In this paper path planning and obstacle avoidance for a statically stable biped robot using PRM and reinforcement learning is discussed. The main objective of the paper is to compare these two methods of path planning for applications involving a biped robot. The statically stable biped robot under consideration is a 4-degree of freedom walking robot that can follow any given trajectory on flat ground and has a fixed step length of 200 mm. It is proved that the path generated by the first method produces the shortest smooth path but it also increases the computational burden on the controller, as the robot has to turn at almost all steps. However the second method produces paths that are composed of straight-line segments and hence requires less computation for trajectory following. Experiments were also conducted to prove the effectiveness of the reinforcement learning based path planning method.     

基于Webots的蛇形机器人翻滚运动仿真及实现

针对蛇形机器人的侧向翻滚运动,给出一种建立正交关节蛇形机器人三维空间运动模型的方法,提出了一种更为简单的实现蛇形机器人侧向翻滚运动的舵机输入函数.通过选择不同的控制参数,可以实现蛇形机器人"U"字形和"V"字形侧向翻滚运动.在Webots移动机器人仿真软件上进行正交关节蛇形机器人翻滚运动仿真,并在蛇形机器人本体上进行试验,验证了所提控制规律的有效性.     

基于GA优化双足机器人步态控制的CPG模型研究

由于传统人工规划产生步态是比较僵硬,缓慢的,缺乏灵活的自组织能力,与真正生物步态存在很大差异;而生物能很好利用中枢模式发生器的自激行为产生有节律的协调运动从而适应多种复杂环境,但普通CPG控制策略又会使关节间出现抖动,影响步态的控制效果;文中提出了以生物中枢模式发生器模型为核心建立双足机器人控制系统,并对CPG的参数进行遗传算法的高效优化,提高了系统性能,消除了关节的抖动;通过MATLAB仿真验证基于GA参数优化的CPG控制机理的双足机器人节律运动控制方法是有效的,并得到了很好的控制效果。     

VisionBug: A Hexapod Robot Controlled by Stereo Cameras

A six-legged robot system demonstrating reactive behaviors of simple organisms—walking between two walls, steering around obstacles, making turns at corners, and making U-turns at pathway dead-ends—is described. The system, named VisionBug, uses no active range sensor but only a stereo pair of cameras for sensing the surroundings. The system assumes the surroundings to be consisting of mostly a ground surface, although the surface could have a varying geometric relationship with the robot due to the jiggling nature of legged motion. By the use of the image-to-image mapping induced to the stereo images by the ground surface, the system is able to avoid explicit 3D reconstruction and the use of optical flow altogether in locating through-ways. Specifically, it regards image features not respecting the ground-induced mapping as obstacles, and express the obstacles in terms of a 2D distribution on the ground. Based on the distribution information, which is further time-delay compensated, a simple fuzzy control mechanism is used to command the legged motion. Experiments show that the system is effective for demonstrating the above-mentioned behaviors in textured environment, at a speed fast enough for many applications.     

Energy-Optimal Design of Walking Machines

In a general definition of robot components given by Wolfram Stadler, communications and power supply are included showing the close relation between robots and walking machines. Both of them are based on mechatronics allowing variable programmable operations.Biped walking represents a complex motion of sophisticated systems in nature as well as in engineering. A young human requires more than 1 year to learn walking while old humans need additional devices for save walking. While passive machines walk only on inclined planes, active machines may walk in all kinds of terrains. However, the active devices known from literature consume so much energy that their operation time is very restricted.In this paper the modeling of walking systems using the method of multibody dynamics is presented including the contact and impact problem inherent to biped walking. The limit cycle of passive motions is investigated as well as the related stability using shooting approaches with optimization techniques. The active machines proposed are controlled using the principles of inverse dynamics and advanced linear control strategies. In particular, the energy consumption between passive and active walking machines is compared by a coefficient of efficiency. At the time being human walking is still the most efficient and it is considered as a benchmark for the mechatronic design of walking machines.