Humanoid robots can walk stably on flat ground, regular slopes, and stairs. However, because of their rigid and flat soles, adapting to unknown rough terrains is limited, moreover, to maintain large scale four-point c...Humanoid robots can walk stably on flat ground, regular slopes, and stairs. However, because of their rigid and flat soles, adapting to unknown rough terrains is limited, moreover, to maintain large scale four-point contact for foot structures to keep balance is usually a key technical problem. In order to solve these problems, the control strategy and foot structures should be improved. In this paper, a novel flexible foot system is proposed. This system occupies 8 degrees of freedom （DOF）, and can obtain larger support region to keep in four-point contact with uneven terrains; Novel cable transmission technology is put forward to reduce complexity of traditional mechanism and control strategy, and variation of each DOF is mapped to cable displacement. Furthermore, kinematics of this new system and a global dynamic model based on contact-force feedback are analyzed. According to stability criterion and feedback sensor information, a method calculating the optimal attitude matrix of contact points and joint variables is introduced. Virtual prototyping models of a 30-DOF humanoid robot and rough terrain are established to simulate humanoid robot walking on uneven ground, and feasibility of this system adapted to uneven terrain and validity of its control strategy are verified. The proposed research enhances the capability of humanoid robots to adapt to large scale uneven ground, expands the application field of humanoid robots, and thus lays a foundation for studies of humanoid robots performing tasks in complex environments in place of humans.展开更多
There are many theories and tools for human or robot motion simulation,but most of them require complex calculations.The LNZN model(a simplified model named by the proposers)simplifies the human model and facilitates ...There are many theories and tools for human or robot motion simulation,but most of them require complex calculations.The LNZN model(a simplified model named by the proposers)simplifies the human model and facilitates simulation of the Ground Reaction Force(GRF)of body landing by spring damping model and ignoring joint rotation movements,which can reduce the amount of computation obviously.In this paper,the LNZN model of human running is selected as the basis and is modified to obtain the LNZN model of a robot,which expands the application of the LNZN model.According to the structure of the human foot,a foot structure is then added to the simplified model to reduce the GRF.We also applied driving forces to the new model to simulate the whole high jump motion of the robot to expand the functions of the LNZN model.The obtained GRF data were anastomotic to the actual experimental results.In addition,the effects of variables,such as the mass,hardness,and damping,of the foot on the GRF at the moment of landing were also explored.Finally,based on the guidelines obtained for the design of the robot’s foot structure,we fabricated new robot’s feet and installed them on the actual robot and achieved a better cushioning effect than the original foot in experiments.展开更多
当前主流的仿人机器人都采用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...当前主流的仿人机器人都采用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。展开更多
仿人机器人行走稳定性研究是机器人领域一大研究热点,目前主要依据动力学模型规划稳定步态,但依靠步态规划形成的运动模式往往需要复杂的运算,并且机器人的运动形式单一.为实现机器人多样化步态的生成,在模仿学习的框架下对机器人的步...仿人机器人行走稳定性研究是机器人领域一大研究热点,目前主要依据动力学模型规划稳定步态,但依靠步态规划形成的运动模式往往需要复杂的运算,并且机器人的运动形式单一.为实现机器人多样化步态的生成,在模仿学习的框架下对机器人的步态模仿问题展开研究,利用人体行走信息作为示教数据,实现仿人机器人对人体行走过程的模仿学习,在简化运动规划的同时使机器人的运动步态更具多样化与拟人化.为满足机器人在步态模仿过程中的稳定性,基于零力矩点(zero moment point,ZMP)判据补偿质心偏移,利用滞回曲线确定行走过程中支撑脚的切换以实现稳定性控制.基于NAO机器人的模仿学习系统仿真研究结果表明:ZMP判据的引入有效地保证了机器人对人体示教步态模仿的稳定性,基于滞回曲线的支撑脚选取保证了支撑脚切换的平稳.展开更多
基金supported by National Natural Science Foundation of China (Grant No. 50775008)PhD Programs Foundation of Ministry of Education of China (Grant No. 200800061019)Hubei Provincial Digital Manufacturing Key Laboratory Foundation of China (Grant No. SZ0602)
文摘Humanoid robots can walk stably on flat ground, regular slopes, and stairs. However, because of their rigid and flat soles, adapting to unknown rough terrains is limited, moreover, to maintain large scale four-point contact for foot structures to keep balance is usually a key technical problem. In order to solve these problems, the control strategy and foot structures should be improved. In this paper, a novel flexible foot system is proposed. This system occupies 8 degrees of freedom （DOF）, and can obtain larger support region to keep in four-point contact with uneven terrains; Novel cable transmission technology is put forward to reduce complexity of traditional mechanism and control strategy, and variation of each DOF is mapped to cable displacement. Furthermore, kinematics of this new system and a global dynamic model based on contact-force feedback are analyzed. According to stability criterion and feedback sensor information, a method calculating the optimal attitude matrix of contact points and joint variables is introduced. Virtual prototyping models of a 30-DOF humanoid robot and rough terrain are established to simulate humanoid robot walking on uneven ground, and feasibility of this system adapted to uneven terrain and validity of its control strategy are verified. The proposed research enhances the capability of humanoid robots to adapt to large scale uneven ground, expands the application field of humanoid robots, and thus lays a foundation for studies of humanoid robots performing tasks in complex environments in place of humans.
基金funded by National Natural Science Foundation of China(No.62073041).
文摘There are many theories and tools for human or robot motion simulation,but most of them require complex calculations.The LNZN model(a simplified model named by the proposers)simplifies the human model and facilitates simulation of the Ground Reaction Force(GRF)of body landing by spring damping model and ignoring joint rotation movements,which can reduce the amount of computation obviously.In this paper,the LNZN model of human running is selected as the basis and is modified to obtain the LNZN model of a robot,which expands the application of the LNZN model.According to the structure of the human foot,a foot structure is then added to the simplified model to reduce the GRF.We also applied driving forces to the new model to simulate the whole high jump motion of the robot to expand the functions of the LNZN model.The obtained GRF data were anastomotic to the actual experimental results.In addition,the effects of variables,such as the mass,hardness,and damping,of the foot on the GRF at the moment of landing were also explored.Finally,based on the guidelines obtained for the design of the robot’s foot structure,we fabricated new robot’s feet and installed them on the actual robot and achieved a better cushioning effect than the original foot in experiments.
文摘当前主流的仿人机器人都采用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。
文摘仿人机器人行走稳定性研究是机器人领域一大研究热点,目前主要依据动力学模型规划稳定步态,但依靠步态规划形成的运动模式往往需要复杂的运算,并且机器人的运动形式单一.为实现机器人多样化步态的生成,在模仿学习的框架下对机器人的步态模仿问题展开研究,利用人体行走信息作为示教数据,实现仿人机器人对人体行走过程的模仿学习,在简化运动规划的同时使机器人的运动步态更具多样化与拟人化.为满足机器人在步态模仿过程中的稳定性,基于零力矩点(zero moment point,ZMP)判据补偿质心偏移,利用滞回曲线确定行走过程中支撑脚的切换以实现稳定性控制.基于NAO机器人的模仿学习系统仿真研究结果表明:ZMP判据的引入有效地保证了机器人对人体示教步态模仿的稳定性,基于滞回曲线的支撑脚选取保证了支撑脚切换的平稳.
