一类无足自驱动系统的运动特性分析

建立了一类简谐激励作用下、两自由度含干摩擦无足自驱动系统的力学模型,描述并分析了系统的运动特性,得到了系统参数选择的最佳范围。研究发现:在低频区,随着激励频率ω的减小,擦边分岔诱导系统碰撞次数逐渐增加,直至颤振序列;在高频区,系统存在混沌运动。在一个完整周期内,基体的运动由黏滞、正向驱进和负向驱进三种中的一种或多种组成;系统平均驱进速度■对激励频率ω和质量比μ_m的变化较敏感,摩擦比f、间隙δ、刚度比μ_k对系统的影响相对较小,质量比μ_m的最佳选择范围为0.4,0.8];系统正向和负向驱进的最大平均速度出现在低频区和质量比较小时;在高频区,基体趋于黏滞状态。该研究结果和方法,可为无足自驱动系统的设计及参数优化提供相应的理论依据。

Motion characteristics analysis of a wheel-free self-driving system

A mechanical model of a two-degrees-of-freedom self-driving system with dry friction subject to simple harmonic excitation is established. The motion characteristics of the system are described and analyzed, and the optimal range of system parameter selection is obtained. The study found that in the low frequency region, with the decrease of the excitation frequency , the number of the impact induced by the grazing bifurcation gradually increases until the chatter sequence; In the high frequency, the chaotic motion can be observed; In a complete cycle, the motion of the substrate consists of one or more of three types: sticking motion, forward drive motion, and negative drive motion; the average driving speed of the system is sensitive to changes in the excitation frequency and mass ratio , the friction ratio , clearance and stiffness ratio have relatively weak influence on the system, and the best choice range of mass ratio is ; the maximum average speed of the forward and negative drive of the system occurs in the low frequency region and the small mass ratio; in the high frequency region, the substrate tends to be sticking motion.The research results and methods in this paper can provide some theoretical basis for the design and parameter optimization of the wheel-free self-driving system.