基于主-被动复合式变刚度柔性关节的四足机器人仿生机理研究

Quadruped robot has higher flexibility on motion, and it is better tuned for all terrains. So it has a broad application prospect in various fields such as rescue and relief work, military and anti-terrorism etc. The impact resistance of joint and flexible-stability control of the system are the key scientific problems to improve the performance of the robot motion. To solve the above two problems, the canine animal is as bionic object in the project. In order to breaking through the technology of hybrid active-passive variable stiffness flexible joints, the movement mechanism of canine animal is researched. and stability control method of quadruped robot with variable stiffness flexible joint is proposed .On this basis a kind of quadruped robot is developed, whose legs with variable elastic stiffness. The research content is as follows. 1)Based on movement process observation experiment of dog, its biomechanics law of joints is studied. Its variable stiffness characteristic of joints is analyzed. Its kinematic model and dynamic model are built. And joint cushion with mechanism of using energy is shown. 2) The hybrid active-passive variable stiffness flexible joints mechanism design is studied, following with the variable stiffness realization mechanism of the bionic flexible joint is revealed . Its dynamic model is built, and the energy amplification mechanism is discussed. Then based on the joint's energy amplification, mechanism optimization and dimension synthesis of variable stiffness active flexible joints are realized. 3)Based on hybrid active-passive variable stiffness flexible joints, the leg mechanism is designed. Based on stability and energy consumption index, configuration design of quadruped robot is optimized. So the stable movement control method is proposed based on optimizing energy consumption. This project will improve the bionic movement effectiveness of the quadruped robot by variable stiffness flexible joints. At the same time, this project promotes the development of bionic robot, so it has important values in the theory and application.

四足机器人运动灵活性高、地形适应能力强，在抢险救灾、军事反恐等领域具有广阔的应用前景。关节的抗冲击性与系统的柔顺稳定控制是提高足式机器人运动性能的关键科学问题。针对以上两个问题，本项目以犬类动物为仿生对象，研究其运动机理，旨在突破主-被动复合式变刚度柔性关节技术，提出具备可变刚度柔性关节的四足机器人稳定控制方法。研究内容：1）通过犬运动实验揭示犬关节变刚度特性，建立其运动学与动力学模型，研究犬关节的缓冲作用及能量运用机理；2）提出一种主-被动复合式变刚度柔性关节机构，建立刚柔耦合动力学模型，揭示仿生柔性关节的变刚度实现机理，并基于能量放大机理实现机构优化与尺度综合；3）基于主-被动复合式变刚度柔性关节的四足机器人，研究其运动稳定性与能量消耗规律，提出一种基于能耗优化的稳定运动控制方法。本项目从变刚度柔性关节入手，提高四足机器人的仿生运动效果，促进仿生机器人的发展，具有重要的理论与应用价值。

足式机器人作为最接近哺乳类生物运动形式的机器形态，具有灵活的运动形式及出众的地面适应能力，其高运动频率与速度一直是研究人员的热门研究领域。但是四足机器人仍存在运动部件受冲击力大、磨损严重、功耗大、续航能力差等亟待解决的关键问题。针对这些问题，本项目取得创新性工作及成果如下：.1）从仿生学角度对犬的解剖结构和运动机理进行了详细研究，得到犬结构对运动状态的影响规律.通过简化犬骨骼结构，建立其结构模型,对其进行运动学分析分析，给仿生四足机器人的运动学分析奠定了基础。.2）研制了同时具备主、被动变刚度特性的柔性关节apVSJ。通过设计不同轮廓线的凸轮盘，apVSJ可实现任意变化趋势的被动变刚度特性,apVSJ可通过小功率伺服电机实现关节输出刚度的主动调节，根据实际工况提高足式机器人运动性能。提出了四足机器人腿部关节的主、被动变刚度策略，阐明了变刚度柔性关节在四足机器人中应用的现实意义。.3）设计了一款基于apVSJ的全肘式四足仿生机器人样机。设计了基于能量优化的稳定运动控制策略。进行了样机的原地蹲起实验、原地踏步实验和样机直线行走实验。最后对实验结果进行了分析，通过发现实验中出现的问题对样机设计和控制算法不足进行改正。.本项目从变刚度柔性关节入手，基于柔性关节的变刚度控制，提高了四足机器人的仿生运动效果，促进了仿生机器人的发展，具有重要的理论与应用价值。