Zhang Zhongyuan, Zhang Lei, Guan Mingjing, Zhang Shuai, Jiao Tengfei
Department of Automation, College of Engineering, Ocean University of China, Qingdao 266404, China.
Sensors (Basel). 2023 Jul 12;23(14):6341. doi: 10.3390/s23146341.
This study proposes a novel variable air pressure supply structure based on the electromagnetic effect. This structure can be implemented in various soft robots driven by air pressure, including pneumatic artificial muscles, pneumatic soft grippers, and other soft robots. The structure's main body comprises a hollow circular tube, a magnetic piston arranged in the tube, and an electromagnetic solenoid nested outside the tube. The electromagnetic solenoid is designed with special winding and power supply access modes, generating either an attractive force or a repulsive force on the magnetic piston. This solenoid conforms with the magnetic piston expectation in the tube by changing the polarity direction. The interior of the whole structure is a closed space. The gas is conveyed to the soft robot by the gas guide hoses at the two ends of the structure, and the expansion energy of the compressed gas is fully utilized. Then, the gas supply pressure is controlled to drive the robot. The mathematical model of the structure is established based on the analysis of the electromagnetic force and gas pressure on the piston. The simulation results show that the structure's inherent vibration characteristics under various parameters align with expectations. The real-time automatic optimization of the controller parameters is realized by optimizing the incremental proportional-integral-derivative (PID) controller based on a neural network. The simulation results show that the structure can meet the application requirements. The experimental results show that the proposed gas supply structure can provide a continuous pressure supply curve with any frequency in a specific amplitude range and has an excellent tracking effect on the sinusoidal-like pressure curve.
本研究提出了一种基于电磁效应的新型可变气压供应结构。这种结构可应用于各种由气压驱动的软体机器人，包括气动人工肌肉、气动软夹爪及其他软体机器人。该结构主体包括一个空心圆管、一个置于管内的磁性活塞以及一个套在管外的电磁螺线管。电磁螺线管采用特殊的绕组和供电接入方式设计，对磁性活塞产生吸引力或排斥力。通过改变极性方向，该螺线管与管内磁性活塞的预期相契合。整个结构内部为封闭空间。气体通过结构两端的导气软管输送到软体机器人，压缩气体的膨胀能量得到充分利用。然后，控制供气压力以驱动机器人。基于对活塞上电磁力和气压的分析建立了该结构的数学模型。仿真结果表明，该结构在各种参数下的固有振动特性符合预期。通过基于神经网络优化增量比例积分微分（PID）控制器，实现了控制器参数的实时自动优化。仿真结果表明，该结构能够满足应用要求。实验结果表明，所提出的供气结构能够在特定幅值范围内提供任意频率的连续压力供应曲线，并且对类正弦压力曲线具有出色的跟踪效果。
