Hybrid force control of astronaut rehabilitative training robot under active loading mode

In order to mitigate the effects of space adaptation syndrome(SAS) and improve the training efficiency of the astronauts, a novel astronaut rehabilitative training robot(ART) was proposed. ART can help the astronauts to carry out the bench press training in the microgravity environment. Firstly, a dynamic model of cable driven unit(CDU) was established whose accuracy was verified through the model identification. Secondly, to improve the accuracy and the speed of the active loading, an active loading hybrid force controller was proposed on the basis of the dynamic model of the CDU. Finally, the actual effect of the hybrid force controller was tested by simulations and experiments. The results suggest that the hybrid force controller can significantly improve the precision and the dynamic performance of the active loading with the maximum phase lag of the active loading being 9° and the maximum amplitude error being 2% at the frequency range of 10 Hz. The controller can meet the design requirements.

带框钢支撑加固含有薄弱层的RC框架抗震性能研究

为研究含有薄弱层的RC框架的抗震加固方法,采用带框钢支撑对薄弱层进行加固并进行拟静力试验研究。以某抗震承载力不足的既有3层框架结构为原型,设计和制作试验模型。采用3点混合控制加载,观察试验现象,得到楼层剪力与层间位移的滞回曲线,比较模型各层的初始刚度和刚度退化情况。研究结果表明:采用带框钢支撑对薄弱层进行加固后,薄弱层的初始刚度和承载力均有较大幅度的提高,模型各层均表现出一定的塑性变形和耗能能力。试验模型的破坏模式表明:带框钢支撑会对框架梁产生附加剪力,造成框架梁剪切破坏,在后续研究中需要注意支撑布置对结构破坏模式的影响。