气动与堵塞机构耦合的变刚度软体驱动器动态建模与控制方法

Soft robot plays a rather important role in exploring and detecting complicated environment such as military reconnaissance, disaster rescue and so on. Current research mainly emphasizes on improvement of its pliancy function, with less consideration of controllability of stiffness, which means that soft robot can display high pliancy in motion as well as strong stiffness in implementing task. In this application, based on combination of the positively driving network pneumatic and passively driving jamming mechanism, design of soft actuator that is simultaneously stiffness-flexible is proposed, and its variable stiffness mechanism, dynamic modeling method, and controlling of flexibility will be studied. Firstly, the soft actuator model based on connection of pneumatic and jamming mechanism is designed and its variable stiffness formulation mechanism is studied; Next, piecewise constant curvature is used to create the kinematics model of soft actuator, and revised kinematics model that can compensate errors is suggested; Next, delay modeling method for soft actuator and dynamic modeling method under the situation of variable carrying stiffness is researched. Moreover, self-adaptive controlling method, complimentary method of connection delay, method of force division for soft machine arm and its optimization are designed step by step; Lastly, with aim of designing stiffness-flexible soft machine arm, vibrating climbing soft robot, and the snake robot which can move in complicated environment, soft actuator experiment is carried out. The above research will give theoretical and technological support to the stiffness-flexible soft robotics.

软体机器人在军事侦察、灾难救援等复杂环境探索与检测方面具有重要的应用价值，当前的研究重点多集中于提高柔顺性能，但未考虑其实时的刚柔可控性，即要求运动时表现出高柔性，执行任务时又能展示出强刚度。本申请拟结合主动驱动的网络气动结构与被动驱动的堵塞机构的优势，提出实时变刚度的软体驱动器设计方案，研究其变刚度形成机理、动态建模方法及刚柔控制方法。首先，设计气动-堵塞机构耦合的软体驱动器模型，研究其变刚度机理；其次，应用分段常曲率模型建立软体驱动器的运动学模型，提出补偿误差的修正运动学模型；再次，研究软体驱动器迟滞建模方法及变负载变刚度条件下的动态建模方法，进而设计自适应控制方法，耦合迟滞的补偿方法，软体机械臂抓取时力/位分配与优化控制方法；最后，以变刚度软体机械臂，振动杆系攀爬软体机器人和复杂环境中运动的机器蛇为设计目标，开展软体驱动器实验验证。该研究有望为变刚度软体机器人提供新的理论和技术支持。

软体机器人运动时具有高柔性，执行任务时又能展示出强刚度，在军事侦察、灾难救援等复杂环境探索与检测方面具有重要的应用价值。本项目结合了主动驱动的网络气动结构与被动驱动的堵塞机构的优势，提出实时变刚度的软体驱动器，研究其变刚度形成机理、动态建模方法及刚柔控制方法，具体工作如下：.首先，提出了气动-堵塞机构耦合的软体驱动器模型，利用赫兹接触模型、离散元方法以建立变刚度机构的数学模型，进而设计变刚度软体机械臂、软体攀爬机器人、软体抓手三种软体机器人。.其次，利用分段常曲率法对软体机器人建立运动学模型，利用ABAQUES软件对三种软体机器人进行有限元建模仿真；对软体机械臂进行物理分析，求得动能、势能和弹性势能，采用拉格朗日动力学方程，求解得到软体机械臂的动力学普遍方程，对于攀爬机器人则相应建立其与接触面粘滞力学模型；.再次，考虑到软体材料的迟滞非线性特性，应用Prandtl-Ishlinskii模型以及Bouc-Wen模型分别建立软体机器人的气压-位移迟滞模型，应用Hopfield神经网络对参数进行辨识，经过分析验证，该模型能够动态表征软体机械臂的气压-位移迟滞现象；.最后，为提高软体机器人的控制精度，分别应用PID控制、自适应控制和滑模控制方法对软体驱动器的轨迹规划阶段，变刚度及抓取阶段，力/位优化控制阶段进行分析，提升变刚度软体驱动器/机械臂可控性。.在上述理论分析基础上，结合3D打印以及硅胶浇筑等技术制作三种机器人样机，并进行弯曲、拉伸、攀爬、末端力测量以及变刚度等实验。实验结果表明，设计的软体机械臂刚度变化范围为0.025N/m-0.135N/m，具有优越的变刚度性能，能完成大多数日常任务。经过迟滞补偿后的软体机械臂，位移控制精度能够达到1mm，并且能够动态参数辨识，克服了机械臂磨损下模型不准确的缺点。设计的软体攀爬机器人在6气腔时，能够完成在斜平面上运动，并且效果良好。设计的软体抓手可对尺寸为20cm，480g以内的物体进行稳定无损抓取。该研究有望为变刚度软体机器人设计与刚度调控提供新的理论和技术支持。