双足机器人RCG姿态控制算法的研究

稳定步行是仿人双足机器人开展实际作业的基础,也是研究的难点和热点.为了提高对仿人机器人步行失稳的响应速率和控制准确性,克服利用陀螺仪进行姿态测量及控制无法完整表述机器人运动状态,从而造成控制滞后的缺点.本文提出了RCG姿态控制算法,在以角速度和角度作为控制参量的模型基础上,引入机器人运动过程中的加速度作为姿态判断和调整的影响因子,实现对机器人行走过程的反馈控制,提高了双足机器人对失稳状态的响应速率和响应的准确性.通过对自主搭建的机器人样机进行测试,结果表明：当双足机器人步行失稳时,RCG姿态控制算法比以角速度和角度作为参量的控制算法能够更快速、准确的修正姿态偏差,保持姿态稳定.     

小型仿人机器人的设计及步态规划

针对现有仿人形机器人造价高的缺点,设计一款低成本的小型双足机器人研究平台.根据人类步行过程及人体生理结构.依据模糊控制与专家控制相结合的理论提出一种简单的双足机器人模型.并根据仿生学原理确定机器人的自由度配置及各关节的比例尺寸.然后,利用目前通用的行为规划软件对双足机器人步态规划进行仿真.并在平坦地面上进行相应行走试验.实验证明.根据人行走模式对机器人进行步态规划的算法稳定可行.为机器人的教学和科研提供了良好的实验平台.     

小型仿人机器人的设计及步态规划

针对现有仿人形机器人造价高的缺点,设计一款低成本的小型双足机器人研究平台。根据人类步行过程及人体生理结构．依据模糊控制与专家控制相结合的理论提出一种简单的双足机器人模型,并根据仿生学原理确定机器人的自由度配置及各关节的比例尺寸。然后,利用目前通用的行为规划软件对双足机器人步态规划进行仿真,并在平坦地面上进行相应行走试验。实验证明,根据人行走模式对机器人进行步态规划的算法稳定可行,为机器人的教学和科研提供了良好的实验平台。     

双足机器人的行走模型及步态规划

双足步行机器人是一个多变量、强耦合、非线性和变结构的复杂动力学系统,是机器人研究领域中的一个重要分支。根据人类的步行过程及人体的生理结构提出了一种简单的双足机器人模型,分析了双足机器人在平坦的地面上脚面抬起高度为。的最小能量消耗的行走方式,并进行了步态规划的研究．     

ZMP理论在双足步行机器人步态控制中的应用

为了解决双足步行机器人的步态控制问题,利用静态步行时ZMP点与重心的特殊联系,构造重心模型来校验机器人的行为数据.同时,将机器人的动作细分为一个个的动作元素,即建立行为数据库.机器人可通过行为数据库来构造出新的、更加复杂的动作.通过完成构造双足步行机器人上台阶的复杂动作,充分说明了这种控制方法的可行性.     

基于DSP的双足机器人运动控制系统设计

在仿人机器人研究领域,双足步行控制一直是其难点。主要介绍基于TI的DSP芯片TMS320F2812设计双足机器人的基本运动控制系统,围绕机器人腿部无刷直流电机的驱动进行优化设计。系统采用PWM进行电机调速,辅助以补偿参数,通过步态指令,验证电机运转的精确性、稳定性和系统的可操作性。电机调试为CCS仿真、步态规划和独立行走提供试验平台,使机器人能够实现步行功能。     

双足步行机器人8路PWM信号联动控制算法研究

针对双足步行机器人的控制要求及8路PWM信号的产生机理,研究了10自由度双足步行机器人的联动控制算法,同时进行了延时分析,最后将该算法用于自行设计的10自由度双足步行机器人中。从而成功实现了机器人的直线前进、转弯、上楼梯等动作。     

基于PIC单片机的六足机器人的协调控制

根据仿生原理以及六足步行机器人各关节运动的协调性、准确性的控制要求,确定了基于PIC单片机控制的控制系统硬件结构和混合闭环的伺服结构控制方案.控制系统的硬件电路部分主要包括控制器、传感器和电机驱动模块.控制器和传感器分别采用8位PIC系列单片机PIC16F877和反射式红外传感器.六足机器人的驱动则是采用直流伺服电机.针对六足机器人步态控制算法给出的数据特点,采用了先对脉冲总数最大的关节进行插补,然后按照关节间脉冲总数的比例关系再对其他关节进行插补的新插补算法,实现了机器人各关节的指令在每一个位置控制周期内的协调.     

双足机器人步行参数对行走稳定性的影响

双足机器人在步行过程中,步行参数对其稳定性有很重要的影响。本文依据ZMP理论,将ZMP点与支撑范围的关系作为判别步行稳定性的依据,以此提出一种方法研究步行参数对稳定性的影响,通过matlab编程然后在ADAMS中进行仿真验证,得到步行参数(步长、步行周期等)对稳定性影响的规律,能够为以后机器人的步态规划提供一定的参考。     

双足机器人避障与步态规划研究

针对双足机器人的步态控制方案是保证其稳定快速运行的重要条件,也是其得到跨越式发展的重要保障.关于ZMP概念的应用可以有效解决双足机器人的各舵机步态行程问题,通过应用偏导方程把质心位置与时间函数紧密联合起来,从而进一步推得有关相关舵机的步态位置.该设计所得的机器人具有仿生机器人在路面行走能力,并且能够及时躲避障碍物,具有可控性强性,敏捷性,和较高的鲁棒性.动态避障是根据光电传感器判别调节步态,其既可以判别脚底二维平面的光幕信号也可判别周围光幕信号,具有控制意义的在规定地点转向与避障.最终通过仿真与实物行走避障等调试与判别总体实现问题.实验结果表明该方案具有可行性和有效性,从而对双足直立机器人在未来的广泛应用做出有效根据.     

Gait Synthesis and Sensory Control of Stair Climbing for a Humanoid Robot

Stable and robust walking in various environments is one of the most important abilities for a humanoid robot. This paper addresses walking pattern synthesis and sensory feedback control for humanoid stair climbing. The proposed stair-climbing gait is formulated to satisfy the environmental constraint, the kinematic constraint, and the stability constraint; the selection of the gait parameters is formulated as a constrained nonlinear optimization problem. The sensory feedback controller is phase dependent and consists of the torso attitude controller, zero moment point compensator, and impact reducer. The online learning scheme of the proposed feedback controller is based on a policy gradient reinforcement learning method, and the learned controller is robust against external disturbance. The effectiveness of our proposed method was confirmed by walking experiments on a 32-degree-of-freedom humanoid robot.     

A Type-2 Fuzzy Switching Control System for Biped Robots

In this paper, a type-2 fuzzy switching control system is proposed for a biped robot, which includes switched nonlinear system modeling, type-2 fuzzy control system design, and a type-2 fuzzy modeling algorithm. A new switched system model is proposed to represent the continuous-time dynamic and discrete-event dynamic of a walking biped as a whole, which is helpful to analyze the closed-loop stability of the biped locomotion. A type-2 fuzzy switching control system is proposed for the switched system model to guarantee the gait stability and to achieve a robust control performance with a simplified control scheme. Finally, we propose a new fuzzy c-mean variance algorithm for the type-2 fuzzy system modeling to capture the variance of each clustering means, which can translate random uncertainties of original data into rule uncertainties. Simulation results are reported to show the performance of the proposed control system model and algorithms.     

Stabilizing and Direction Control of Efficient 3-D Biped Walking Based on PDAC

This paper proposes a 3-D biped dynamic walking algorithm based on passive dynamic autonomous control (PDAC). The robot dynamics is modeled as an autonomous system of a 3-D inverted pendulum by applying the PDAC concept that is based on the assumption of point contact of the robot foot and the virtual constraint as to robot joints. Due to autonomy, there are two conservative quantities named “PDAC constant,” which determine the velocity and direction of the biped walking. We also propose the convergence algorithm to make PDAC constants converge to arbitrary values, so that walking velocity and direction are controllable. Finally, experimental results validate the performance and the energy efficiency of the proposed algorithm.      

Stable Walking Pattern for an SMA-Actuated Biped

In this paper, a walking pattern filter for shape-memory-alloy (SMA)-actuated biped robots is presented. SMAs are known for their high power-to-mass ratio as well as slow response. When used as actuators, the SMA speed limitation can potentially lead to stability problems for biped robots. The presented filter adapts the human motion such that an SMA biped robot maintains a stable walking pattern. The zero moment point (ZMP) is used as the main criterion of the filter to guarantee the stability of the motion. The SMA actuators are designed based on the dynamics and kinematics of the motion. The response time of each SMA actuator is modeled in order to estimate the behavior of the actuator in realizing the given trajectory. After applying the delay times to the motion, the new trajectories are generated and evaluated by the filter for the ZMP criterion. Using simulations, it is shown that the filter can generate smooth trajectories for the SMA-actuated biped robots. The filter furthermore guarantees the stability of a robot mimicking the human walking motion.     

Reliable gait planning and control for miniaturized quadruped robot pet

This paper proposes a gait planning and control algorithm for the quadruped robot pet commercialized by Dasarobot, Korea. Reliable motion and online characteristics are the key requisites for the motion planning algorithm of a commercialized robot. At joint control level of the proposed gait control, sample-based interpolation makes joint trajectory tractable for small motor and controller of the miniaturized robot. Centroid body sway ensures walking stability to achieve reliability of the proposed gaits at the motion planning level. By using ground coordinates representation, it is possible to integrate several online gaits and realize a compact and efficient gait planning algorithm. Experimental results are presented to verify the proposed gait planning and control algorithm.     

Genetic algorithm tuning of Lyapunov-based controllers: anapplication to a single-link flexible robot system

In this paper, a systematic controller design approach is proposed to guarantee both closed-loop stability and desired performance of the overall system by effectively combining genetic algorithms (GAs) with Lyapunov's direct-controller design method. The effectiveness of the approach is shown by using a simple and efficient decimal GA optimization procedure to tune and optimize the performance of a Lyapunov-based robust controller for a single-link flexible robot. The feedback gains of the controller are tuned by the GA optimization process to achieve good results for tip motion control of the single-link flexible robot based on some suitable fitness functions. The paper includes results of simulation experiments demonstrating the effectiveness of the proposed genetic algorithm approach     

Improved Algorithm for Solving Inverse Kinematics of Biped Robots

Mobile Networks and Applications - Inverse kinematics is an important basic theory in walking control of biped robot. This study focuses on the parameter setting using the improved algorithm in...     

Robust PID control of fully-constrained cable driven parallel robots

In this paper dynamic analysis and robust PID control of fully-constrained cable driven parallel manipulators are studied in detail. Since in this class of manipulators cables should remain in tension for all maneuvers in their workspace, feedback control of such robots becomes more challenging than that of conventional parallel robots. In this paper, structured and unstructured uncertainties in dynamics of the robot are considered and a robust PID controller is proposed for the cable robot. To ensure that all cables remain in tension internal force concept is used in the proposed PID control algorithm. Then, robust stability of the closed-loop system with proposed control algorithm is analyzed through Lyapunov direct method and it is shown that by suitable selection of the PID controller gains, the closed-loop system would be robustly stable. Finally, the effectiveness of the proposed PID algorithm is examined through experiments on a planar cable driven robot and it is shown that the proposed control structure is able to provide suitable performance in practice.