Integrated Systems for High Bandwidth Ultra High Precision Actuation

驱动是一种在机器系统内施加力以产生受控运动的方法。例如，驱动的应用包括用于制造目的的材料挤压、测试机器中的部件操纵、飞机中的飞行控制面调整、喷墨打印、机器人系统中的定位以及主动振动/噪声衰减。根据不同的物理现象，执行器有多种类型，如压电式、电式、电磁式、气动、液压和螺杆式。性能的差异与能够施加的力的幅度和频率有关，以及运动范围(行程)和相关的精度。例如，压电致动器可以在高频下提供很大的力，但行程不到1毫米。或者，液压执行机构可以在长冲程(例如，盖茨黑德千禧大桥开口处3米处)提供很大的力，尽管施力的频率相对较低。一个理想的执行器应该在所有指标上都具有高性能：力水平；频率范围或带宽；行程范围；以及精度。目前还不存在这样的执行器。这项拟议研究的目的是调查与物理特性、设计集成和控制相关的问题，以使驱动接近实现理想。随着新的科学和工业创新的潜在产生，未来的好处将是广泛的。这项研究将集中在多种致动介质的设计和集成上，并采用优化的控制策略来产生具有高性能指标的致动器。将对多个地区进行调查。首先，将评估压电致动器在液压缸内产生的动态压力，这将允许高频致动。此外，还将使用压电式装置使活塞和连杆密封变形，从而使密封提供的摩擦力可用于控制大行程和高频运动。还将使用压电阀实现高频致动和亚微米控制，以精确调整液压流量。滑动部分和执行部分的基本物理相互作用需要深入分析，以便使用准确的系统模型来完成高性能控制器的详细设计。最后，集成系统将在一个实验设备上实现，该设备将用于验证研究方法。

Actuation is the means by which forces can be applied within machine systems to give rise to controlled motion. Applications of actuation include, for example, the extrusion of material for manufacturing purposes, the manipulation of components in test machines, flight control surface adjustment in aircraft, ink jet printing, positioning in robotic systems, and active vibration/noise attenuation. There is a variety of actuator types based on different physical phenomena e.g. piezoelectric, electric, electromagnetic, pneumatic, hydraulic, and screw. The differences in performance relate to the amplitudes and frequencies of the forces that are capable of being applied, together with the motion range (stroke) and the associated precision. For example, piezoelectric actuators can deliver large forces at high frequencies, but the strokes are less than 1 mm. Alternatively, hydraulic actuators can deliver large forces over long strokes (e.g. 3 m in the opening of the Gateshead Millennium Bridge), though the frequency of the forcing is relatively low. An ideal actuator would have high performance over all metrics: force levels; frequency range or bandwidth; stroke range; and precision. At present no such actuator exists. The aim of the proposed research is to investigate the issues relating to physical characteristics, design integration and control that would enable actuation as close to the ideal to be realised. The future benefits would be widespread with the potential generation of new scientific and industrial innovations. The research will be focused on the design and integration of multi-actuation media with optimised control strategies to yield an actuator that has high performance metrics. A number of areas will be investigated. Firstly, piezoelectric actuators will be assessed for the generation of dynamic pressures within hydraulic cylinders, which would allow high frequency actuation. Additionally, piezoelectric devices will be used to deform piston and rod seals such that the friction forces provided by the seals may be used to control large stroke and high frequency motion. High frequency actuation and sub-micron control will also be achieved using a piezo-actuated valve for precise adjustment of hydraulic flows. The basic physical interactions of sliding and actuated parts will require in-depth analysis in order that the detailed design of high performance controllers can be accomplished using accurate system models. Finally, the integrated system will be realised in an experimental facility, which will be used to validate the research methodology.