Bionic Mechanism and Kinematics Analysis of Hopping Robot Inspired by Locust Jumping

A flexible-rigid hopping mechanism which is inspired by the locust jumping was proposed, and its kinematic characteris- tics were analyzed. A series of experiments were conducted to observe locust morphology and jumping process. According to classic mechanics, the jumping process analysis was conducted to build the relationship of the locust jumping parameters. The take-offphase was divided into four stages in detail. Based on the biological observation and kinematics analysis, a mechanical model was proposed to simulate locust jumping. The forces of the flexible-rigid hopping mechanism at each stage were ana- lyzed. The kinematic analysis using pseudo-rigid-body model was described by D-H method. It is confirmed that the proposed bionic mechanism has the similar performance as the locust hind leg in hopping. Moreover, the jumping angle which decides the jumping process was discussed, and its relation with other parameters was established. A calculation case analysis corroborated the method. The results of this paper show that the proposed bionic mechanism which is inspired by the locust hind limb has an excellent kinematics performance, which can provide a foundation for design and motion planning of the hopping robot.

Development of Gesture-Changeable under-actuated Humanoid Robotic Finger

Robotic fingers, which are the key parts of robot hand, are divided into two main kinds： dexterous fingers and under-actuated fingers. Although dexterous fingers are agile, they are too expensive. Under-actuated fingers can grasp objects self-adaptively, which makes them easy to control and low cost, on the contrary, under-actuated function makes fingers feel hard to grasp things agilely enough and make many gestures. For the purpose of designing a new finger which can grasp things dexterously, perform many gestures and feel easy to control and maintain, a concept called ＂gesture-changeable under-actuated＂ （GCUA） function is put forward. The GCUA function combines the advantages of dexterous fingers and under-actuated fingers： a pre-bending function is embedded into the under-actuated finger. The GCUA finger can not only perform self-adaptive grasping function, but also actively bend the middle joint of the finger. On the basis of the concept, a GCUA finger with 2 joints is designed, which is realized by the coordination of screw-nut transmission mechanism, flexible drawstring constraint and pulley-belt under-actuated mechanism. Principle analyses of its grasping and the design optimization of the GCUA finger are given. An important problem of how to stably grasp an object which is easy to glide is discussed. The force analysis on gliding object in grasping process is introduced in detail. A GCUA finger with 3 joints is developed. Many experiments of grasping different objects by of the finger were carried out. The experimental results show that the GCUA finger can effectively realize functions of pre-bending and self-adaptive grasping, the grasping processes are stable. The GCUA finger excels under-actuated fingers in dexterity and gesture actions and it is easier to control and cheaper than dexterous hands, becomes the third kinds of finger.

Novel miniature pneumatic pressure regulator for hopping robots

A novel miniature pressure regulator is fabricated and studied. The regulator can easily be integrated into portable mechatronics or miniature robotic applications because of its lightweight and compact size. An especial poppet is designed to minimize its size and to withstand high-pressure. The pressure regulator is designed for a hopping robot which is powered by a combustion system. The hopping robot has great moving capacities such as jumping over big obstacles, wails and dit- ches. The regulator helps the hopping robot to decrease size and weight, and to sustain high pres- sure of oxygen and fuel tank. It will maintain constant output pressure to obtain suitable proportion of oxygen and fuel in the combustion cylinder. Dynamic simulation of the miniature pneumatic pres- sure regulator is performed. Experiments on prototype of miniature pneumatic pressure regulator are also carried out to validate the performance and satisfied performance is obtained.

Force Control in Monopod Hopping Robot While Landing

In this paper, the issue of control of impact forces generated during the interaction between the hopping ro-bot toe and the ground while landing has been considered. The force thus generated can damage the robot altogether. With the objective to control these impact forces, impedance control strategy has been applied to the hopping robot system. The dynamics pertaining to the impact between robot toe and ground has been modeled as in case of a ball bouncing on the ground. Bond Graph theory has been used for the modeling of the hopping robot system. Simulation results show that impact forces generated during the landing has been controlled to a specified limiting value. This model and the corresponding analysis can be further extended for understanding the dynamics involved in continuous hopping of robot with constant height and velocity control.

Design on hopping locomotion mechanism

A new type of locomotion mechanism is introduced in this paper. With vibrating motors used in controling the movement of the hopping locomotion mechanism, the simple hopping locomotion mechanism had two motors, when the current went through the vertical motor, the vertical motor would vibrate to cause the mechanism to go forward, and when the current went through the horizontal motor, the mechanism will go around itself. A spring was added to the mechanism to change the natural frequency of the mechanism, when the frequency of the motor was equal to the natural frequency of the mechanism, the mechanism would hop resonantly. With the resonant hopping, the load of the mechanism was greatly enlarged, and some sensors could be added to the mechanism. Optical sensors were used to detect the infrared source, the current that went through the sensors related to the distance between the infrared light. Three optical sensors was put on the left, right and the front the mechanism, when the mechanism detect the special infrared source, it would turn itself to the light, and go forward to the light. The experiments of the mechanism shown that the mechanism could work well on different surfaces freely, and the resonant hopping locomotion mechanism with infrared sensors could move to the special light by automatic regulation. Experimental results and theoretical studies demonstrate that the innovative design for hopping locomotion mechanism is superior.

HIT anthropomorphic robotic hand and finger motion control

Nowadays many anthropomorphic robotic hands have been put forward. These hands emphasize different aspects according to their applications. HIT Anthropomorphic Robotic Hand (ARhand) is a simple, lightweight and dexterous design per the requirements of anthropomorphic robots. Underactuated self-adaptive theory is adopted to decrease the number of motors and weight. The fingers of HIT ARhand with multi phalanges have the same size as those of an adult hand. Force control is realized with the position sensor, joint torque sensor and fingertip torque sensor. From the 3D model, the whole hand, with the low power consumption DSP control board integrated in it, will weigh only 500 g. It will be assembled on a BIT-Anthropomorphic Robot.

CPG Control for Biped Hopping Robot in Unpredictable Environment

A CPG control mechanism is proposed for hopping motion control of biped robot in unpredictable environment. Based on analysis of robot motion and biological observation of animal＇s control mechanism, the motion control task is divided into two simple parts： motion sequence control and output force control. Inspired by a two-level CPG model, a two-level CPG control mechanism is constructed to coordinate the drivers of robot joint, while various feedback information are introduced into the control mechanism. Interneurons within the control mechanism are modeled to generate motion rhythm and pattern promptly for motion sequence control; motoneurons are modeled to control output forces of joint drivers in real time according to feedbacks. The control system can perceive changes caused by unknown perturbations and environment changes according to feedback information, and adapt to unpredictable environment by adjusting outputs of neurons. The control mechanism is applied to a biped hopping robot in unpredictable environment on simulation platform, and stable adaptive motions are obtained.

A Bio-Inspired Hopping Kangaroo Robot with an Active Tail

Inspired by kangaroo＇s locomotion, we report on developing a kangaroo-style hopping robot. Unlike bipeds, quadrupeds, or hexapods which altemate the legs for forward locomotion, the kangaroo uses both legs synchronously and generates the forward locomotion by continuous hopping behavior, and the tail actively balances the unwanted angular momentum generated by the leg motion. In this work, we generate the Center of Mass （CoM） locomotion of the robot based on the reduced-order Rolling Spring Loaded Inverted Pendulum （R-SLIP） model, for matching the dynamic behavior of the empirical robot legs. In order to compensate the possible body pitch variation, the robot is equipped with an active tail for pitch variation compensation, emulating the balance mechanism of a kangaroo. The robot is empirically built, and various design issues and strategies are addressed. Finally, the experimental evaluation is executed to validate the performance of the kangaroo-style robot with hopping locomotion.

A Single-legged Robot Inspired by the Jumping Mechanism of Click Beetles and Its Hopping Dynamics Analysis

The click beetle can jump up with a hinge when it is on the dorsal side.This jumping mechanism is simple and suitable as an inspiration for designing a simple,small,and reliable hopping robot.We report a single-legged robot inspired by the jumping mechanism of click beetles.It is 85 mm high,60 mm long,and 41 mm wide,and weighs about 49 g.The robot has good hopping performance that the hopping height is about 4 times-4.3 times of its body height.It is capable for rescue missions that require to enter enclosed spaces through cracks and narrow channels.In addition,hopping dynamics of the robot is important to understand its jumping mechanism and improve the robot’s hopping performance.But existing dynamic study does not complete the analysis including all stages in the hopping which are pre-hopping,take-off,and air-flying.We propose the decomposition method to study dynamics of the three stages separately,and synthesize them with related parameters.The dynamic synthesis of multi-motion states in a hopping cycle of the single-legged hopping robot is implemented.The hopping performance and dynamic synthesis theory of the robot are verified by simulations and experiments.Our study helps lay the foundation for design and hopping control of simple hopping robot systems.

一种新型跳跃机器人的运动特性研究

针对一种新型的跳跃机器人,提出了其单腿跳跃机构的分析模型。采用D-H方法,建立了跳跃机器人着地和腾空两个阶段的运动学方程;开展正、逆运动学研究,给出了机器人在跳跃过程中的运动位姿;利用Adams软件,对跳跃机器人的弹跳过程进行了动力学特性仿真。研究结果表明,仿真得到的跳跃机器人水平/竖直方向的位移、水平/竖直方向的速度曲线的变化趋势均与试验结果相吻合,从而证明了所建立的新型跳跃机器人结构模型的可行性和机器人运动特性研究方法的有效性。

弹跳式机器人研究

机器人在实际应用时 ,很多时候要求其具备弹跳装置以便跃过障碍物或沟渠 .而多轮驱动以及爬行机器人无法满足这种要求 ,因此迫切需要研制具有弹跳能力的机器人 .本文对当前各种弹跳机构的工作机理进行分析与比较 。

星面探测仿生间歇式跳跃机器人设计及实现

设计了一种面向行星表面探测的小型间歇式仿生跳跃机器人.利用机构学中变胞思想及齿轮-连杆闭链机构的力转换特性,提出了一种杆长可控的非对称齿轮-六杆仿袋鼠跳跃机构,对其间歇式跳跃过程进行了分析,并针对跳跃能力和起跳躯干姿态平稳性进行了机构构型与尺寸优化设计.基于优化设计结果,进行了跳跃机器人运动仿真分析和样机试验.结果表明,该仿生跳跃机器人具有非线性递增的弹跳动力、平稳的起跳姿态以及较高的能量利用效率,可通过太阳能供电、单一微小电机驱动实现间歇式跳跃运动.

弹跳机器人翻转机构的设计与优化

为了提高弹跳机器人的地面适应性,解决弹跳机器人落地后的翻转问题,从蝗虫和龟类的翻转研究中得到启示,设计结构简便、易于控制、集支撑与翻转功能为一体的翻转机构。应用三角重心理论,分析机器人翻转的原理和翻转过程。在仿真的基础上,对翻转机构进行构型和尺寸优化,保证机器人结构紧凑,轻量化和较高的电动机利用率。搭建翻转机构平台,验证了翻转机构原理的可行性和优化设计的正确性,为弹跳机器人进一步的创新研究提供了理论基础和依据。

弹跳式机器人研究综述

机器人在实际应用时,很多时候要求其具备弹跳装置以便跃过障碍物或沟渠。而多轮驱动以及爬行或步行机器人无法满足这种要求,因此迫切需要研制具有弹跳能力的机器人。本文对弹跳机器人及目前的研究进行了综合的介绍和分析,并在此基础上介绍了作者在这方面所做的工作。本文同时也对未来弹跳机器人的发展趋势做了展望。

间歇性单足弹跳机器人落地冲击及稳定性分析

弹跳式机器人落地时与地面的撞击会造成机载设备的损坏 ,而且由于足部受力不均导致机构易翻转 ,难以保持正常的姿态继续弹跳。本文首先建立间歇式弹跳机构的双质量弹簧模型 ,对其进行动力学分析 ,并将弹跳动作划分为四阶段 ,分析了除起跳外其他三个阶段中所受外界作用。经过计算分析 ,最终归纳总结出五条减小落地冲击力及保持稳定的改善措施 。

用于行星探测的跳跃机器人研究

综述了用于行星探测的跳跃机器人(PEHR)的研究现状,分析了PEHR研究所面临的问题,并预测了其发展趋势。

仿袋鼠机器人跳跃运动步态的运动学

提出了仿袋鼠跳跃机器人机构模型及运动学研究的方法。基于对袋鼠的运动结构及录像资料的研究,提出了仿袋鼠机器人单腿四杆跳跃机构的分析模型,采用D-H法,建立了机器人着地与腾空两个阶段的运动学方程, 进行了正运动学研究,给出了机器人在跳跃过程中的运动位姿及躯干质心的运动轨迹表达式,并利用雅可比矩阵建立了机器人躯干质心与关节之间的微分运动关系及速度分析方法。采用Matlab编程,结合实例对机器人进行了运动仿真运算,对结果进行了分析讨论,解释了袋鼠跳跃运动跃远度大而耗能低和运动稳健的运动机理。研究结果与录像观察和生物学实测研究结果相吻合,从而证明了这一仿生跳跃机构模型的可行性和仿生机构运动研究方法的有效性。

仿袋鼠柔性跳跃机器人的驱动力特性研究

依据袋鼠生物体的运动结构和跳跃运动特点,利用扭转弹簧模拟其关节柔性和肌肉的储能作用,提出仿袋鼠柔性跳跃机器人的伪刚体机构模型。应用凯恩法建立仿袋鼠跳跃机器人的动力学方程。基于MATLAB6.5,结合实例对机器人的运动和驱动力特性进行了仿真分析。分析结果表明:利用柔性机构可降低仿生跳跃机器人跳跃运动所需关节驱动力和能量消耗,同时也揭示了袋鼠跳跃运动快而耗能低的规律。

液压驱动单腿跳跃机器人柔顺着地分析与控制

为缓解液压驱动足式机器人动态步态行走时着地瞬间足端冲击对机器人系统及其运动控制的影响,提出了一种基于关节运动规划的机器人柔顺着地控制方法。以液压驱动单腿跳跃机器人为研究对象,分析机器人足端着地冲量,通过选择合适的机器人着地姿态和减小机器人着地前足端速度实现机器人柔顺着地,为此在空中相进行余弦速度曲线关节运动轨迹规划,以及着地相进行余弦函数关节运动轨迹规划。将该方法分别应用于基于MATLAB/Simulink软件建立的仿真模型和试验样机进行单腿竖直跳跃控制实验,仿真和试验结果显示采用该方法的机器人跳跃控制消除了足端着地瞬间地面作用力在膝关节液压缸无杆腔形成的液压冲击,实验结果表明提出的基于关节运动规划的机器人柔顺着地控制方法合理可行。

一种间歇式弹跳机器人的机构设计与跳跃性能分析

为研究复杂地形下弹跳机器人跳跃轨迹的可控性问题,设计一种基于齿轮—六杆变胞机构的间歇式弹跳机器人。通过改变齿轮—六杆变胞机构的拓扑结构,机器人具有储能、能量锁定与释放、改变储能大小以及调整姿态角的功能,起跳过程中弹跳力具有仿生特性。根据机器人的结构特征设计翻转机构,使其倒地后自行翻转复位。在理论建模基础上,对机器人的跳跃运动进行仿真以研究储能改变和姿态角调整对跳跃轨迹的影响。研制间歇式弹跳机器人原理样机并进行跳跃运动试验,仿真和试验结果较吻合。结果表明,该间歇式弹跳机器人的机构设计具有可行性,跳远度和跳高度具有可控性:跳远度的控制可通过改变储能大小实现;储能相同时,跳高度的控制可通过调整姿态角实现。为需要轨迹规划的间歇式弹跳机器人的设计提供了一种方案。