Research on bionic quadruped robot based on hydraulic driver

A prototype of hydraulically powered quadruped robot is presented.The aim of the research is to develop a versatile robot platform which could travel fleetly in outdoor terrain with long time of endurance and high load carrying ability.The current version is 1.1m long and 0.48 m wide,and weights about 150 kg.Each leg has four rotational joints driven by hydraulic cylinders and one passive translational joint with spring.The torso carries the control system and the power system.A novel control algorithm is developed based on a Spring-Loaded Inverted Pendulum model and the principle of joint function separation.The robot can not only cross a 150 mm high obstacle in static gait and trot at 2.5km/h and lkm/h on the level-ground and 10°sloped-terrain respectively,but also automatically keep balanced under lateral disturbance.In this paper,the mechanical structure and control systems are also discussed.Simulations and experiments are carried out to validate the design and algorithms.     

Design of trotting controller for the position-controlled quadruped robot

This work presents a controller designed for position-controlled quadrupedal dynamic locomo-tion, aiming at simple and robust trotting control .The controller takes the torso attitude angles and velocities into planning foot trajectories .Firstly design of the servo motor actuated quadruped robot is introduced and the kinematic equations are deduced .Then a scheme is presented for controlling the robot torso attitude based on the virtual leg model .Furthermore , it demonstrates the design of the controller which enables the robot to have a wide range of trotting gaits and omni-directional mo-tions.Finally, results of robust trotting in various speeds , path tracking and push recovery in simu-lation are reported , and results of trotting on real quadruped robots will be studied .     

Stability margin of the quadruped bionic robot with spinning gait

Spinning gait is valuable for quadruped robot, which can be used to avoid obstacles quickly for robot walking in unstructured environment.A kind of bionic flexible body is presented for quadruped robot to perform the spinning gait.The spinning gait can be achieved by coordinated movement of body laterally bending and legs swing, which can improve the mobility of robot walking in the un-structured environments.The coordinated movement relationship between the body and the leg mechanism is presented.The stability of quadruped robot with spinning gait is analyzed based on the center of gravity ( COG) projection method.The effect of different body bending angle on the stabili-ty of quadruped robot with spinning gait is mainly studied.For the quadruped robot walking with spinning gait, during one spinning gait cycle, the supporting polygon and the trajectory of COG pro-jection point under different body bending angle are calculated.Finally, the stability margin of quadruped robot with spinning gait under different body bending angle is determined, which can be used to evaluate reasonableness of spinning gait parameters.     

Dynamic stability of quadruped robot walking on slope with trot gait

The dynamic stability of a quadruped robot trotting on slope was analyzed.Compared with crawl gait, trot gait can improve walking speed of quadruped robots.When a quadruped robot trots, each leg is in the alternate state of swing phase or supporting phase, and two legs in the diagonal line are in the same phase.The feet in the supporting phase form a supporting region on the ground.When a quadruped robot walks on slope, the vertical distance from zero moment point ( ZMP) to the sup-porting diagonal line is defined as ZMP offset distance.Whether this distance is less than the maxi-mum offset distance or not, the stability of robot trotting on slope can be judged.The foot trajectory was planned with the sinusoidal function.Based on the kinematic analysis, the ZMP offset distance of quadruped robot under different slope angles, step length and step height was calculated, then the reasonable slope angle, step length and step height for quadruped robot trotting on slope to keep dy-namic stability can be determined.On the other hand, the posture angle of quadruped robot should be controlled within the desired range.Computer simulations were executed to verify the theoretical analysis.The study will provide reference for determining reasonable step parameters of the quadru-ped robot.     

轮式移动机器人轨迹跟踪控制方法

针对轮式移动机器人轨迹跟踪这一典型控制任务,提出了基于模糊控制规则的滑模控制方法。该方法采用等速趋近律,利用连续函数代替符号函数获得切换控制律,最后运用Lyapunov理论证明系统的稳定性。仿真结果表明该方法不但能够有效的跟踪机器人的参考轨迹,还能有效的减少在控制中的抖振现象。即使存在外界干扰的情况下,也具有良好的控制品质。     

旋转对称型四足机器人站立-翻滚变形规划

设计了一种可实现翻滚的四足机器人,不仅可以采用步行方式通过崎岖地形,而且可以自主变形成为滚动体,从而采用翻滚模式通过平坦地形.机器人四肢由弓形杆件组成,机体采用球冠外形,根据旋转对称原则设计肢体的几何参数和质心分布.由站立模式向翻滚模式变形过程中,将机器人简化为平面连杆机构,建立了变形过程中机器人质心运动学模型.提出势能变化最小的变形策略,采用惩罚函数法,优化变形终止时刻机器人的位形.针对变形运动学方程的非线性特性,采用最小二乘法进行关节轨迹规划.结果表明机器人质心运动轨迹满足变形策略.     

A gait planning method applied to hexapod biomimetic robot locomotion

In order to fulfill the goal of autonomous walking on rough terrain, a distributed gait planning method applied to hexapod biomimetic robot locomotion is proposed based on the research effort of gait coordination mechanism of stick insect. The mathematical relation of walking velocity and gait pattern was depicted, a set of local rules operating between adjacent legs were put forward, and a distributed network of local rules for gait control was constructed. With the interaction of adjacent legs, adaptive adjustment of phase sequence fluctuation of walking legs resulting from change of terrain conditions or variety of walking speed was implemented to generate statically stable gait. In the simulation experiments, adaptive adjustment of inter-leg phase sequence and smooth transition of velocity and gait pattern were realized, and static stableness was ensured simultaneously, which provided the hexapod robot with the capability of walking on rough terrain stably and expeditiously.     

农用轮式移动机器人系统仿真研究

农用轮式移动机器人是一个复杂的机电一体化系统,在移动机器人的设计过程中,如果缺乏设计经验就需要通过系统仿真的方法来辅助移动机器人的设计.本文针对移动机器人的机械子系统和智能控制系统进行了仿真研究,减少了设计过程中的失误,缩短了设计和开发的周期.     

基于角度模型的机器人驱动系统参数辨识

针对直流电动机驱动的轮式机器人,提出一种根据机器人轮子编码器读数辨识机器人驱动系统参数的算法,并与传统的根据速度输出来辨识机器人参数的方法进行了比较.仿真计算证明:根据编码器数据辨识有更好的精度及抗干扰能力.     

轮式移动机器人轨迹跟踪控制

基于轮式移动机器人的运动学模型,以速度为控制量,采用控制Lyapunov函数设计出一种具有全局渐近稳定的速度跟踪控制器。仿真结果证明了该方法的有效性。     

仿人机器人未知地面行走控制方法研究

介绍了一种仿人机器人未知地面行走的控制算法 .该算法通过踝关节六维力 \力矩传感器信息感知地面环境 ,确定步态参数 ,利用基于ZMP稳定判据的规划方法进行实时运动规划 ,实现机器人稳定行走 .     

基于综合导向的轮式移动机器人自适应轨迹跟踪控制

分析了不确定的具有非完整约束轮式移动机器人系统的轨迹跟踪问题,提出了一种自适应的轨迹跟踪控制方法,该方法在运动学模型的基础上通过引入状态微分反馈实现.同时,该控制方法提出在对轮式移动机器人进行导航时引入人工场,使其和位姿误差一起作用完成导航控制.基于轮式移动机器人的仿真实验,以及实际轮式移动机器人的控制实验表明,该方法可以对不确定的轮式移动机器人轨迹跟踪进行有效控制,而且在导航中使轮式移动机器人具有更理想的轨迹.     

一种轮腿结合式步行机的步态

提出用周期函数G(X)和正函数H(X)表达步行机的支撑点位置。解决了在一个步态周期内轮子作多周期运动的动态支撑点位置描述问题,给出并证明了支撑点位置的计算公式,进而讨论了支撑点位置的极限问题。     

Path planning based on sliding window and variant A*algorithm for quadruped robot

In order to improve the adaptability of the quadruped robot in complex environments , a path planning method based on sliding window and variant A * algorithm for quadruped robot is presen-ted .To improve the path planning efficiency and robot security , an incremental A*search algorithm ( IA*) and the A*algorithm having obstacle grids extending ( EA*) are proposed respectively .The IA* algorithm firstly searches an optimal path based on A * algorithm, then a new route from the current path to the new goal projection is added to generate a suboptimum route incrementally .In comparison with traditional method solving path planning problem from scratch , the IA* enables the robot to plan path more efficiently .EA* extends the obstacle by means of increasing grid g-value, which makes the route far away from the obstacle and avoids blocking the narrow passage .To navi-gate the robot running smoothly , a quadratic B-spline interpolation is applied to smooth the path . Simulation results illustrate that the IA* algorithm can increase the re-planning efficiency more than 5 times and demonstrate the effectiveness of the EA * algorithm.     

基于Petri网模型控制的步行机器人的自由步态

为解决步行机器人在复杂环境下的运动问题 ,根据步行运动的特点 ,提出了单腿运动的 Petri网控制模型 ,又以5足步行机为例 ,建立了与其腿数相对应的多腿协调控制模型 ,并制定了相应的控制策略。在此基础上 ,重新提出了有关步行机器人自由步态的有关概念及其运动规划算法 ,定义了保持静稳定行走状态的运动条件和判断方法。最后对 5足步行机在平面不连续落足区内的跨沟运动进行了仿真。仿真结果表明 ,提出的运动控制模型和自由步态能够自动适应运动环境 ,实现离散地形下的步行运动     

对话型轮式移动机器人的开发

阐述了对话型轮式移动机器人的开发工作。通过对大型语音识别和语音合成软件IBM ViaVoice的开发，将语音识别系统与机器人控制系统有机结合，实现了人和机器人的简单对话。行走部分为一个全方位轮式移动机构，具有很强的灵活性。     

Adaptive trajectory tracking control of two-wheeled self-balance robot

Wheeled mobile robot is one of the well-known nonholonomic systems.A two-wheeled self-balancerobot is taken as the research objective.This paper carried out a detailed force analysis of the robot andestablished a non-linear dynamics model.An adaptive tracking controller for the kinematic model of anonholonomic mobile robot with unknown parameters is also proposed.Using control Lyapunov function(CLF),the controller's global asymptotic stability has been proven.The adaptive trajectory trackingcontroller d...     

基于LIPM的双足机器人变步长行走规划

为了提高双足机器人步行运动的灵活性,提出了一种基于线性倒立摆模型的双足步行规划算法.该算法首先根据所要达到的步长,获得支撑腿切换时质心的位置;然后,根据线性倒立摆模型的运动特性,计算出质心到达上述位置所需要的时间;最后,根据该时间对摆动脚用正弦曲线进行规划,使之能够在恰当的时刻到达所需的落脚点位置进行支撑脚的切换.该算法可使双足机器人在运动中变化步长,很好地提高其步行的灵活性.通过真实机器人的实验,验证了该方法的有效性和实用性.     

轮式移动机械手的点-点运动规划方法

基于轮式移动机械手的移动性与操作性间的关系和轮式移动平台的优化运动区域,提出了一种新的轮式移动机械手点－点运动规划问题的优化准则,此准则不但包括移动平台的运动代价和机械手的代价,而且还包括移动机械手偏离优化构所需的运动代价,最后通过仿真证明了此协调方法的可行性。