Legged robots have better performance on discontinuous terrain than that of wheeled robots. However, the dynamic trotting and balance control of a quadruped robot is still a challenging problem, especially when the ro...Legged robots have better performance on discontinuous terrain than that of wheeled robots. However, the dynamic trotting and balance control of a quadruped robot is still a challenging problem, especially when the robot has multi-joint legs. This paper presents a three-dimensional model of a quadruped robot which has 6 Degrees of Freedom （DOF） on torso and 5 DOF on each leg. On the basis of the Spring-Loaded Inverted Pendulum （SLIP） model, body control algorithm is discussed in the first place to figure out how legs work in 3D trotting. Then, motivated by the principle of joint function separation and introducing certain biological characteristics, two joint coordination approaches are developed to produce the trot and provide balance. The robot reaches the highest speed of 2.0 m.s-1, and keeps balance under 250 Kg.m.s-1 lateral disturbance in the simulations. The effectiveness of these approaches is also verified on a prototype robot which runs to 0.83 m.s-1 on the treadmill, The simulations and experiments show that legged robots have good biological properties, such as the ground reaction force, and spring-like leg behavior.展开更多
The body of quadruped robot is generally developed with the rigid structure. The mobility of quadruped robot depcnds on the mechanical properties of the body mechanism, It is difficult for quadruped robot with rigid s...The body of quadruped robot is generally developed with the rigid structure. The mobility of quadruped robot depcnds on the mechanical properties of the body mechanism, It is difficult for quadruped robot with rigid structure to achieve better mobility walking or running in the unstructured environment. A kind of bionic flexible body mechanism for quadruped robot is proposed, which is composed of one bionic spine and four pneumatic artificial muscles（PAMs）. This kind of body imitates the four-legged creatures＇ kinematical structure and physical properties, which has the characteristic of changeable stiff＇hess, lightweight, flexible and better bionics. The kinematics of body bending is derived, and the coordinated movement between the flexible body and legs is analyzed. The relationship between the body bending angle and the PAM length is obtained. The dynamics of the body bending is derived by the floating coordinate method and Lagrangian method, and the driving tbrce of PAM is determined. The experiment of body bending is conductcd, and the dynamic bending characteristic of bionic flexible body is evaluated. Experimental results show that the bending angle of the bionic flexible body can reach 18. An innovation body mechanism for quadruped robot is proposed, which has the characteristic of flexibility and achieve bending by changing gas pressure of PAMs. The coordinated movement of the body and legs can achieve spinning gait in order to improve the mobility of quadruped robot.展开更多
针对四足机器人在非结构化环境下的自适应稳定行走问题,提出一种面向未知复杂地形的四足机器人运动规划方法。采用爬行步态,基于零力矩点(Zero moment point,ZMP)稳定性判据进行在线轨迹规划。通过摆动腿的落地规划和感知策略估计未知...针对四足机器人在非结构化环境下的自适应稳定行走问题,提出一种面向未知复杂地形的四足机器人运动规划方法。采用爬行步态,基于零力矩点(Zero moment point,ZMP)稳定性判据进行在线轨迹规划。通过摆动腿的落地规划和感知策略估计未知地形的参数,实时调整各支撑腿的长度以控制机器人躯体的位置和姿态与当前地形相匹配,实现四足机器人对于未知地形高度和坡度变化的自适应。试验结果表明,四足机器人能够在满足稳定性的前提下,对未知复杂地形具有良好的适应能力,验证了该方法的有效性与可靠性。展开更多
基金Acknowledgment This work was supported by the National Hi-tech Research and Development Program of China （863 Program, Grant No. 2011AA040701）, and the National Natural Science Foundation of China （No. 61375097, No. 61175107）
文摘Legged robots have better performance on discontinuous terrain than that of wheeled robots. However, the dynamic trotting and balance control of a quadruped robot is still a challenging problem, especially when the robot has multi-joint legs. This paper presents a three-dimensional model of a quadruped robot which has 6 Degrees of Freedom （DOF） on torso and 5 DOF on each leg. On the basis of the Spring-Loaded Inverted Pendulum （SLIP） model, body control algorithm is discussed in the first place to figure out how legs work in 3D trotting. Then, motivated by the principle of joint function separation and introducing certain biological characteristics, two joint coordination approaches are developed to produce the trot and provide balance. The robot reaches the highest speed of 2.0 m.s-1, and keeps balance under 250 Kg.m.s-1 lateral disturbance in the simulations. The effectiveness of these approaches is also verified on a prototype robot which runs to 0.83 m.s-1 on the treadmill, The simulations and experiments show that legged robots have good biological properties, such as the ground reaction force, and spring-like leg behavior.
基金Supported by National Natural Science Foundation of China(Grant No.51375289)Shanghai Municipal Natural Science Foundation of China(Grant No.13ZR1415500)Innovation Fund of Shanghai Education Commission(Grant No.13YZ020)
文摘The body of quadruped robot is generally developed with the rigid structure. The mobility of quadruped robot depcnds on the mechanical properties of the body mechanism, It is difficult for quadruped robot with rigid structure to achieve better mobility walking or running in the unstructured environment. A kind of bionic flexible body mechanism for quadruped robot is proposed, which is composed of one bionic spine and four pneumatic artificial muscles（PAMs）. This kind of body imitates the four-legged creatures＇ kinematical structure and physical properties, which has the characteristic of changeable stiff＇hess, lightweight, flexible and better bionics. The kinematics of body bending is derived, and the coordinated movement between the flexible body and legs is analyzed. The relationship between the body bending angle and the PAM length is obtained. The dynamics of the body bending is derived by the floating coordinate method and Lagrangian method, and the driving tbrce of PAM is determined. The experiment of body bending is conductcd, and the dynamic bending characteristic of bionic flexible body is evaluated. Experimental results show that the bending angle of the bionic flexible body can reach 18. An innovation body mechanism for quadruped robot is proposed, which has the characteristic of flexibility and achieve bending by changing gas pressure of PAMs. The coordinated movement of the body and legs can achieve spinning gait in order to improve the mobility of quadruped robot.
文摘针对四足机器人在非结构化环境下的自适应稳定行走问题,提出一种面向未知复杂地形的四足机器人运动规划方法。采用爬行步态,基于零力矩点(Zero moment point,ZMP)稳定性判据进行在线轨迹规划。通过摆动腿的落地规划和感知策略估计未知地形的参数,实时调整各支撑腿的长度以控制机器人躯体的位置和姿态与当前地形相匹配,实现四足机器人对于未知地形高度和坡度变化的自适应。试验结果表明,四足机器人能够在满足稳定性的前提下,对未知复杂地形具有良好的适应能力,验证了该方法的有效性与可靠性。
