基于并联机构的车载担架及振动半主动控制研究

Ambulance stretcher based on parallel mechanism and vibration semi-active control

位于救护车车载担架上的卧姿人体,会承受来自路面的多维激励。为了对多维振动进行隔离,改进一种4-PUU并联机构作为车载担架的主体,并在移动副处安装弹簧与磁流变阻尼器,推导隔振系统的动力学与状态空间方程。磁流变阻尼器的可控阻尼力由LQR方法结合限界Hrovat半主动算法得到,研究担架系统在随机路面谱激励下振动半主动控制及隔振性能。研究结果表明:该担架系统能够有效隔离沿坐标轴的平移振动以及绕x轴的旋转振动,采用磁流变阻尼器的振动半主动控制担架系统的隔振性能明显优于被动控制的隔振性能,且能够取得与振动主动控制接近的减振效果。

The supine patients on ambulance stretcher experienced multi-dimensional excitations from the road.In order to isolate the multi-dimensional vibration effectively,an improved 4-PUU parallel mechanism was proposed as the main structure of the stretcher.Springs and magneto-rheological dampers were installed at the prismatic pairs.Dynamic and state-space equations of the vibration isolation system were deduced.The controllable damping force was obtained by combining LQR with Hrovat semi-active algorithm.The semi-active control and vibration isolation capability were addressed with stochastic road profile excitation.The results show that the stretcher system is able to reduce the translational vibrations along the axes and the rotational vibration around the x-axis validly.The vibration isolation capability of semi-active control stretcher system composed of MR dampers is significantly better than passive control system,and it can achieve almost the same vibration isolation performance as active control system.