基于测力平台阵列的双足步行机器人实际零力矩点检测

提出一种多维力测力平台阵列系统,通过机器人行走过程中脚部与平台接触力的测量,并根据. vukobratovic关于ZMP的定义,得到机器人行走过程的ZMP实际轨迹信息,为双足步行机器人的稳态行走步态规划提 供参考依据.更进一步,该系统也可以用作双足步行机器人行走过程步态规划的实验平台.     

A novel compound biped locomotion algorithm for humanoid robots to realize biped walking

In this paper, a compound biped locomotion algorithm for a humanoid robot under development is presented. This paper is organized in two main parts. In the first part, it mainly focuses on the structural design for the humanoid. In the second part, the compound biped locomotion algorithm is presented based on the reference motion and reference Zero Moment Point （ZMP）. This novel algorithm includes calculation of the upper body motion and trajectory of the Center of Gravity （COG） of the robot. First, disturbances from the environment are eliminated by the compensational movement of the upper body; then based on the error between a reference ZMP and the real ZMP as well as the relation between ZMP and CoG, the CoG error is calculated, thus leading to the CoG trajectory. Then, the motion of the robot converges to its reference motion, generating stable biped walking. Because the calculation of upper body motion and trajectory of CoG both depend on the reference motion, they can work in parallel, thus providing double insurances against the robot＇s collapse. Finally, the algorithm is validated by different kinds of simulation experiments.     

双足机器人稳定行走的仿人预测控制研究

针对双足机器人的稳定行走,提出了一种新的仿人预测控制在线步行模式生成方法。把期望零力矩点（ZMP）分解成离线规划好的参考ZMP和实时变化的可变ZMP之和,通过预测控制和其逆系统共同作用对质心运动进行控制,从而生成具有自适应性的步行模式。但单一的预测控制系统对诸如矩形齿状扰动的可变ZMP的跟踪存在较大的误差,结合仿人智能控制对误差的强抑制能力,设计了与预测控制相结合的仿人预测控制系统。仿真实验验证对矩形齿状扰动的可变ZMP,仿人预测系统也能实现较好的跟踪。     

双足机器人自然ZMP轨迹生成方法研究

为了实现双足机器人类人行走,提出了一种基于自然ZMP轨迹的双足机器人步行模式生成方法。在单腿支撑相,根据基于三维线性倒立摆模型,在设定从脚跟到脚趾移动的自然ZMP轨迹后,得到质心轨迹方程;在双腿支撑相采用线性摆模型生成质心轨迹方程。同时给出了在统一坐标系中的多步规划质心轨迹方程。在RoboCup 3D仿真平台实现了采用自然ZMP轨迹的双足机器人类人稳定步行,实验和竞赛结果都验证了该方法的有效性。     

复杂环境下仿人机器人有效支撑区域的感知

当主流的仿人机器人都采ZMP(zero moment point)理论作为稳定行走的判据.实时ZMP点落在支撑足与地面接触形成的多边形支撑区域内是仿人机器人实现稳定步行的必要条件.因此实现仿人机器人在复杂现实环境中稳定行走,必须要求机器人足部感知系统提供足够丰富的地面环境信息,从而可以准确获取支撑区域的形状以实现基于实时ZMP点的稳定控制.文中将柔性阵列力传感器应用于仿人机器人足部感知系统,提出了获取仿人机器人支撑区域形状的方法,而且通过实验验证了其可行性.     

基于全身协调的仿人机器人步行稳定控制

提出利用机器人质心（CoM）雅克比矩阵,实现全身协调补偿的算法。提出机器人的简化模型;分析基于CoM雅克比矩阵的补偿算法;采用CoM/ZMP（零点矩点）、减振和软着陆控制器实时控制双足步行,实现机器人全身协调的稳定控制;通过仿人机器人AFU09的双足步行实验证明该控制方法的有效性。     

基于六维力／力矩传感器的拟人机器人实际ZMP检测

ZMP（Zero Moment Point)作为双足双行机器人动态稳定行走的判据,已应用于世界上银多著名的步行机器人系统。目前国外步行机器人大多采用力／力矩传感器进行ZMP的实际检测计算,但采用六维力／力矩传感器的却不多,而且其安装位置也各不同,国内机器人还都还都处于离线步态规划阶段,只进行理论了ZMP的计算,并没有进行实时检测。本文根据清华大学985重点项目“拟人机器人技术及其系统研究”的研究要求,确定基于六维力／力矩传感系统的实际ZMP检测方案,确这了传感器安装的最佳位置,推导了单脚支撑期,双脚支撑期的实际ZMP计算公式提出了基于ZMP理论的姿态调整方法,以期在实际应用中进行在线步态规划。     

Online Walking Pattern Generation and Its Application to a Biped Humanoid Robot — KHR-3 (HUBO)

The authors propose a simple on-line method for generating a walking pattern for the biped humanoid robot KHR-3 (HUBO). The problem of realizing a walking action in humanoid robots involves two components: generation of the basic walking pattern and the compensation required to maintain the robot's balance. Dynamic walking can be realized by incorporating the real-time stabilizing control algorithm developed for KHR-1, KHR-2 and KHR-3. The walking pattern of KHR-3 has four modes: forward/backward, left/right, curved walking and turning around. In the previous pattern generation of the KHR series, the step time and stride of the robot were fixed, and the walking modes, step time and action of stride without stopping could not be changed. Hence, the flexibility of the walking pattern of the robot needed to be upgraded. The walking pattern in this paper allows variation in the walking mode, step time and stride for each step. The pattern uses a simple mathematical form of trajectory curves, specifically the sine, cosine, linear and third-order polynomial curves, and the superposition of these curves is used to minimize the complexity and burden of the computation. The authors used a third-order polynomial to generate the trajectory of the robot's pelvis. With the aid of a simplified zero-moment point (ZMP) equation, the pelvis trajectories have a direct relationship with the ZMP trajectories. An effective means of generating the trajectories is introduced, and the scheme is verified experimentally under various walking conditions that take into account the step time and stride. The experimental platform, which has human-like features and movement, is briefly introduced here. With a simple kinematical structure and distributed control hardware architecture, the platform was designed to consume relatively low levels of energy. Moreover, the scheme for generating the trajectory is realized for variations to flexible walking.     

基于三维线性倒立摆的仿人机器人步态规划

为了实时调整仿人机器人的步态,提出一种仿人机器人的步态生成方法。把机器人运动简化为三维线性倒立摆运动模式,通过预先规划好的零力矩点(ZMP)轨迹,根据质心(CoM)和ZMP的关系,求出CoM轨迹;再将前向步态和侧向步态简化为七连杆结构和五连杆结构,利用三角定理求出各个关节的角度,结合ZMP方程讨论了行走过程中的稳定性。利用给定的条件进行了系统的仿真,并结合实际系统及其运行状况进行分析,验证了所提出规划方法的有效性。     

考虑综合步行约束的仿人机器人参数化3D 步态规划方法

给出了一种三维环境下双足行走的参数化步态规划方法,建立了仿人机器人13 质量块约束动力学模 型．考虑单腿支撑和双腿支撑无冲击连续切换的六点边界约束条件、可行步态物理约束条件以及ZMP 稳定性约束 条件,以关节输出力矩函数的二次型积分值最小作为优化指标,采用参数化步态优化方法,将复杂关节轨迹的规划 问题转化为分段多项式系数组成的有限参数向量的优化问题,得到了快速和慢速两组光滑无振动的优化步态．仿真 和样机实验验证了该方法的有效性．     

基于运动相似性的仿人机器人双足步行研究

提出了一种基于人体步行运动相似性的仿人机器人双足步行动作设计方法．改进了人体步行轨迹的参 数获取与相似性匹配系统,扩展了相似性函数的适用范围．根据仿人机器人的机械连杆特点定义了步行运动周期中 的关键姿势与子相变换,建立了运动学约束方程,并对行走中出现的动态稳定性问题进行了约束．仿真和实体机器 人实验验证了该方法的有效性．     

Walking Pattern Generation for a Biped Walking Robot Using Convolution Sum

This paper describes a novel walking pattern generation method for a biped humanoid robot using a convolution sum. For a biped walking model, a single mass inverted pendulum model is generally used and the zero moment point (ZMP) equation is described by a decoupled linear differential equation. As a walking pattern generation method for the robot model, a novel method using a convolution sum is proposed in this paper. From the viewpoint of the linear system response, walking pattern generation can be regarded as a convolution of an arbitrary reference ZMP and the walking pattern for an impulse reference ZMP. For the calculation of convolution, the walking pattern for an impulse reference ZMP is first derived from the analytic walking pattern for a step reference ZMP. The convolution sum is then derived in two recursive forms, which can be applied online and offline, respectively. The proposed algorithm requires low computation power, since the walking pattern equation is composed of a recursive form. As the algorithm is expressed in analytic form, it is not necessary to solve optimization problems or calculate the fast Fourier transform, contrary to previous approaches. A computer simulation of walking demonstrates that the proposed algorithm yields excellent accuracy compared to the preview control method — one of the most highly regarded walking pattern generation methods. In addition, the application on the multi-point mass model is shown with the computer simulation.     

双足步行机器人的ZMP-CoP检测及研究

ZMP(零力矩点）和CoP(压力中心)是评价双足步行机构行走稳定性的重要参数．本文在研究了ZMP和CoP两者关系的基础上，根据THBIP-I仿人机器人基于ZMP理论的姿态调整要求和六维力/力矩传感器的安装位置，推导了适用于双足机器人的CoP计算公式，建立了采用六维力/力矩传感器的CoP检测系统．进行了THBIP-I仿人机器人行走过程的实际CoP检测实验，并对实验结果进行了讨论．实验证明了该系统的准确性.     

Walking Control Algorithm of Biped Humanoid Robot on Uneven and Inclined Floor

This paper describes walking control algorithm for the stable walking of a biped humanoid robot on an uneven and inclined floor. Many walking control techniques have been developed based on the assumption that the walking surface is perfectly flat with no inclination. Accordingly, most biped humanoid robots have performed dynamic walking on well designed flat floors. In reality, however, a typical room floor that appears to be flat has local and global inclinations of about 2°. It is important to note that even slight unevenness of a floor can cause serious instability in biped walking robots. In this paper, the authors propose an online control algorithm that considers local and global inclinations of the floor by which a biped humanoid robot can adapt to the floor conditions. For walking motions, a suitable walking pattern was designed first. Online controllers were then developed and activated in suitable periods during a walking cycle. The walking control algorithm was successfully tested and proved through walking experiments on an uneven and inclined floor using KHR-2 (KAIST Humanoid robot-2), a test robot platform of our biped humanoid robot, HUBO.     

Experimental realization of dynamic walking of the biped humanoid robot KHR-2 using zero moment point feedback and inertial measurement

This paper describes a novel control algorithm for dynamic walking of biped humanoid robots. For the test platform, we developed KHR-2 (KAIST Humanoid Robot-2) according to our design philosophy. KHR-2 has many sensory devices analogous to human sensory organs which are particularly useful for biped walking control. First, for the biped walking motion, the motion control architecture is built and then an appropriate standard walking pattern is designed for the humanoid robots by observing the human walking process. Second, we define walking stages by dividing the walking cycle according to the characteristics of motions. Third, as a walking control strategy, three kinds of control schemes are established. The first scheme is a walking pattern control that modifies the walking pattern periodically based on the sensory information during each walking cycle. The second scheme is a real-time balance control using the sensory feedback. The third scheme is a predicted motion control based on a fast decision from the previous experimental data. In each control scheme, we design online controllers that are capable of maintaining the walking stability with the control objective by using force/torque sensors and an inertial sensor. Finally, we plan the application schedule of online controllers during a walking cycle according to the walking stages, accomplish the walking control algorithm and prove its effectiveness through experiments with KHR-2.     

Analyses of biped walking posture by dynamical-evaluating index

In this paper, biped walking posture and design are evaluated through dynamic reconfiguration manipulability shape index (DRMSI). DRMSI is the concept derived from dynamic manipulability and reconfiguration manipulability with remaining redundancy. DRMSI represents the ability of dynamical system of manipulators possessing shape changing acceleration in task space by normalized torque inputs, while the hand motion is assigned as the primary task. Besides, we use visual lifting approach to stabilize the walking and stop falling down. In this research, the primary task is to make the position of the head direct to the desired one as much as possible. And realizing the biped walking is the second task. This research indicates that proposed dynamical-evaluating index is effective in evaluating the biped walking motion and biped humanoid robot has the adjustable configuration to walk with higher flexibility. Flexibility represents the dynamical shape changeability of humanoid robot based on redundancy of the humanoid robot with the premise of the primary task given to keeping the head position high.     

Observer-based dynamic walking control for biped robots

This article presents a novel observer-based control system to achieve reactive motion generation for dynamic biped walking. The proposed approach combines a feedback controller with an online generated feet pattern to assure a stable gait. Using the desired speed of the robot, a preview control system derives the dynamics of the robot’s body, and thereby the trajectory of its center of mass, to ensure a zero moment point (ZMP) movement, which results in a stable execution of the calculated step pattern. Extending the control system by an observer, based on this knowledge and the measured sensor values, compensates for errors in the model parameters and disturbances encountering while walking.     

基于力矩传感器的双足机器人在线模糊步态调整器设计

双足机器人动态行走时,零力矩点轨迹与期望值之间存在一定偏差。利用机器人力矩传感器的输出信号,结合动力学算法实时计算零力矩点的位置,并利用基于模糊逻辑的步态调整算法修正踝关节处的４个关节角,以达到降低零力矩点位置误差,提高系统动态行走稳定性的目的。仿真和实验证实了该算法的有效性。     

基于CAN 总线的机器人脚力传感器的设计及其应用􀀂

ZMP控制理论已广泛应用于双足步行机器人的步态规划中,行走过程中的实际ZMP轨迹,是通过安装在脚部的两个多维脚力传感器获取的力/力矩信息计算得到.文章提出并设计了一种基于CAN总线接口的双足步行机器人集成化脚力传感器,给出了其硬件组成及软件设计,并详细论述了双足步行机器人行走过程中实际ZMP轨迹的计算方法.     

双足机器人预观控制的ZMP补偿步行模式研究

针对双足机器人的稳定行走,提出了一种预观控制的零力距点（ZMP）补偿步行模式在线生成方法。利用实际ZMP与目标ZMP之间的未来误差信息,基于预观控制计算机器人行走过程中质心的补偿量,事先调整质心轨迹来改变步态。最终使实际ZMP更好地跟踪目标值。12自由度的双足机器人动力学仿真验证了所提出方法的有效性,而且机器人能在一定程度不平整地面上实现稳定行走。