夹心式压电驱动履带行驶系统的研究

发布时间：2018-09-08 14:11

【摘要】：在我国二、三期探月工程中,月面巡视探测器(月球车)是实现科学目标不可缺少的基础工具和必备手段。在现有的轮式、腿式和履带式三种月球车基本形式中,履带式以其在越障能力强、沉降小、牵引力大等特点受到广泛关注,但其驱动轮系的机构复杂、重量大阻碍了在月面探测上的应用。本课题利用压电激励和摩擦驱动基本原理,以结构简单、重量小、能耗小和抗污染能力强为目标,探索履带式月面巡视探测器行驶系统的压电驱动新原理。在前期贴片式月球车研究基础上,提出了一种夹心式压电驱动履带行驶系统,开展了压电振子结构优化、表面质点的运动学与动力学行为、接触边界条件与结构动力学行为的相互作用等方面的研究:1.分析了贴片式压电振子的履带驱动原理,针对其功率较小的问题,提出利用夹心式结构压电振子驱动履带的原理和方法。通过梁中四组压电陶瓷具有90度相位差的电压激励,激发梁两端圆环上沿圆周的行波,经摩擦驱动履带运动;2.以工作模态频率差和干扰模态频率差为目标,利用Isight优化软件的多目标优化工具箱调用ANSYS有限元程序进行迭代运算,对压电振子结构进行了优化。工作模态频率差由优化前的605Hz缩小到8Hz,前、后干扰模态频率差由优化前的169Hz和400Hz分别增大到1098Hz和1323Hz;3.通过实验研究了原理样机的运动特性:其最佳工作频率为35.1kHz,启动时间为120ms,制动时间为25ms;瞬时运动速度呈周期性变化;在500V_(pp)的驱动电压下,平均运动速度为72mm/s;在320V_(pp)的驱动电压下,牵引力为0.48N;驱动电压为300V_(pp)时,最大负载重量为1.44kg(样机自重0.4kg)。本文对夹心式压电驱动履带行驶系统进行了结构设计与工作机理的分析,通过对原理样机进行相关实验,验证了设计方案的可行性,但在理论建模、各元件装配工艺、设计及实验方面还需要做进一步的改进和完善,包括接触刚度、粗糙度、预压力与速度之间关系的科学解释和月面环境适应性的研究。
[Abstract]:In the second and third lunar exploration projects in China, lunar rover (lunar rover) is an indispensable basic tool and necessary means to achieve scientific goals. Among the existing three basic forms of the wheel type, leg type and crawler type, the crawler type has attracted wide attention because of its strong ability to overcome obstacles, small settlement and great traction, but the mechanism of its driving gear train is complex. The heavy weight hinders the application of lunar surface detection. Based on the basic principles of piezoelectric excitation and friction driving, the new piezoelectric driving principle of tracked lunar patrol detector is explored in this paper, aiming at simple structure, small weight, low energy consumption and strong anti-pollution ability. On the basis of the previous research on the sticker type lunar rover, a kind of sandwich piezoelectric driving crawler driving system is proposed. The piezoelectric oscillator structure optimization and the kinematics and dynamic behavior of the surface particle are carried out. The interaction between the contact boundary conditions and the dynamic behavior of the structure: 1. This paper analyzes the crawler driving principle of the sticker piezoelectric vibrator. Aiming at the problem of low power, the principle and method of using the sandwich piezoelectric vibrator to drive the crawler are put forward. Through the voltage excitation of 90 degree phase difference in four groups of piezoelectric ceramics in the beam, the traveling waves along the circumference of the two end rings of the beam are excited, and the crawler motion is driven by friction. Aiming at the working mode frequency difference and the interference mode frequency difference, the piezoelectric oscillator structure is optimized by using the multi-objective optimization toolbox of Isight optimization software and the iterative operation of ANSYS finite element program. The operating mode frequency difference is reduced from 605Hz before optimization to 8 Hz, and the frequency difference of interference mode before and after optimization increases from 169Hz and 400Hz to 1098Hz and 1323Hz respectively. The experimental results show that the optimal operating frequency is 35.1kHz, the start-up time is 120msand the braking time is 25ms; the instantaneous motion velocity varies periodically at 500V _ (pp) driving voltage, and the average motion speed is 72mm / s at 500V _ (pp) driving voltage, and at 320V_ (pp) driving voltage, the optimal operating frequency is 35.1 kHz, the braking time is 25ms, the average speed is 72mm / s at 500V _ (pp) driving voltage, and the driving voltage is 320V _ (pp). When the driving voltage is 300V _ (pp), the maximum load weight is 1.44kg (prototype deadweight 0.4kg). In this paper, the structure design and working mechanism of the sandwich piezoelectric drive crawler driving system are analyzed. The feasibility of the design scheme is verified by experiments on the prototype of the principle, but in the theoretical modeling, the assembly process of each component, Further improvements and improvements in design and experiment are needed, including the scientific interpretation of the relationship between contact stiffness, roughness, pre-pressure and velocity, and the study of the environmental adaptability of the lunar surface.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V476.3

【相似文献】