Most quadruped reptiles, such as lizards, salamanders and crocodiles, swing their waists while climbing on horizontal or vertical surfaces. Accompanied by body movement, the centroid trajectory also becomes more of a ...Most quadruped reptiles, such as lizards, salamanders and crocodiles, swing their waists while climbing on horizontal or vertical surfaces. Accompanied by body movement, the centroid trajectory also becomes more of a zigzag path rather than a straight line. Inspired by gecko＇s gait and posture on a vertical surface, a gecko inspired model with one pendular waist and four active axil legs, which is called GPL model, is proposed. Relationship between the waist position, dynamic gait, and driving forces on supporting feet is analyzed. As for waist trajectory planning, a singular line between the supporting feet is found and its effects on driving forces are discussed. Based on the GPL model, it is found that a sinusoidal waist trajectory, rather than a straight line, makes the driving forces on the supporting legs smaller. Also, a waist close to the pygal can reduce the driving forces compared to the one near middle vertebration, which is in accord with gecko＇s body bending in the process of climbing. The principles of configuration design and gait planning are proposed based on theoretical analyses. Finally, a bio-inspired robot DracoBot is developed and both of the driving force measurements and climbing experiments reinforce theoretical analysis and the rationality of gecko＇s dynamic gait.展开更多
研究了被动调谐质量阻尼器(Tuned Mass Damper,TMD)在一种新的安装方式下对悬吊结构平面摆振的控制效果,并考虑悬吊结构质量分布对TMD系统调频的影响。首先基于拉格朗日原理建立了附加双TMD体系双质点悬吊结构的无阻尼自由振动方程,并...研究了被动调谐质量阻尼器(Tuned Mass Damper,TMD)在一种新的安装方式下对悬吊结构平面摆振的控制效果,并考虑悬吊结构质量分布对TMD系统调频的影响。首先基于拉格朗日原理建立了附加双TMD体系双质点悬吊结构的无阻尼自由振动方程,并对质量分布对双质点悬吊结构周期的影响进行了理论分析;然后定义了TMD控制无阻尼自由振动的控制效果评价指标,利用Simulink对运动方程进行数值求解,证明此时TMD对悬吊结构具有一定的控制效果,并对质量分布在TMD调频、质量比与板长摆长比变化情况下对控制效果的影响进行了数值分析,发现控制效果随着双质点的分散而下降的规律,而这种规律与质量比和板长摆长比的变化无关,验证了理论分析中对质点分布影响的推断,并得出TMD应根据悬吊结构质量分布的影响来调频以保证控制效果的结论。展开更多
基金This work was supported by the National Natural Science Foundation of China （No. 51475018） and Beijing Natural Science Foundation （No. 3162018）.
文摘Most quadruped reptiles, such as lizards, salamanders and crocodiles, swing their waists while climbing on horizontal or vertical surfaces. Accompanied by body movement, the centroid trajectory also becomes more of a zigzag path rather than a straight line. Inspired by gecko＇s gait and posture on a vertical surface, a gecko inspired model with one pendular waist and four active axil legs, which is called GPL model, is proposed. Relationship between the waist position, dynamic gait, and driving forces on supporting feet is analyzed. As for waist trajectory planning, a singular line between the supporting feet is found and its effects on driving forces are discussed. Based on the GPL model, it is found that a sinusoidal waist trajectory, rather than a straight line, makes the driving forces on the supporting legs smaller. Also, a waist close to the pygal can reduce the driving forces compared to the one near middle vertebration, which is in accord with gecko＇s body bending in the process of climbing. The principles of configuration design and gait planning are proposed based on theoretical analyses. Finally, a bio-inspired robot DracoBot is developed and both of the driving force measurements and climbing experiments reinforce theoretical analysis and the rationality of gecko＇s dynamic gait.
文摘研究了被动调谐质量阻尼器(Tuned Mass Damper,TMD)在一种新的安装方式下对悬吊结构平面摆振的控制效果,并考虑悬吊结构质量分布对TMD系统调频的影响。首先基于拉格朗日原理建立了附加双TMD体系双质点悬吊结构的无阻尼自由振动方程,并对质量分布对双质点悬吊结构周期的影响进行了理论分析;然后定义了TMD控制无阻尼自由振动的控制效果评价指标,利用Simulink对运动方程进行数值求解,证明此时TMD对悬吊结构具有一定的控制效果,并对质量分布在TMD调频、质量比与板长摆长比变化情况下对控制效果的影响进行了数值分析,发现控制效果随着双质点的分散而下降的规律,而这种规律与质量比和板长摆长比的变化无关,验证了理论分析中对质点分布影响的推断,并得出TMD应根据悬吊结构质量分布的影响来调频以保证控制效果的结论。
