摘要
液压驱动并联加载机构对试件进行多自由度位置/力加载时,受到液压系统非线性因素和试件耦合作用的影响,其位置和力加载自由度的频宽难以提高,导致正弦位置/力响应信号的幅值衰减和相位滞后。为提高系统对正弦位置/力信号的跟踪精度,提出一种改进幅相控制方法。对正弦信号幅值、相位、均值3个特征参数进行评估,将评估后的3个特征参数作为控制变量分别进行控制,给出相应的幅相控制器设计和参数整定方法。实验结果表明,该方法能有效提高正弦位置/力信号的跟踪精度,具有控制结构简单、调节参数少、参数整定方便的特点。
Due to nonlinear factors existed in hydraulic system and coupled interaction from specimen, the bandwidth of position and force degrees of freedom （DOF） of hydraulic actuated parallel loading mechanism （HPLM） can be improved in the limited situation, which results in the amplitude attenuation and phase lag of response sinusoidal position/force signals. To improve the tracking accuracy of sinusoidal signals, some types of amplitude and phase control （APC）, which were based on the Widrow-Hoff learning algorithm, extremum seeking techniques and so on, were proposed by some researchers. However, some shortcomings such as complex control structure, superabundant tuned parameters, and huge computation and so on, made these APC methods difficult to implement. To solve the problem, an improved amplitude and phase control （IAPC） was presented. Three characteristic parameters of sinusoidal signal, which was amplitude, phase and mean value, were estimated and regarded as control variables to be controlled separately. The methods of controller design and control parameter tuning were given. The stability of system under the proposed IAPC was analyzed. To verify the performance of the proposed IAPC experimentally, a 6-DOF hydraulically actuated redundant parallel loading mechanism under position-based hybrid position/force loading control was introduced, and its position/force close-loop frequency response characteristics were presented. The experiments containing sinusoidal position loading, sinusoidal force loading and hybrid sinusoidal position/force loading were done. The experimental results showed that the tracking accuracy of sinusoidal position/force signals could be significantly improved under the proposed IAPC with the characteristics of simple control structure and less and easily tuned parameters.
作者
高长虹
何彪
曲智勇
丛大成
GAO Changhong;HE Biao;QU Zhiyong;CONG Dacheng(Aviation Equipment Research Institu＇te, AVIC Qing-an Group Co. , Ltd. , Xi＇ an 710077, China;School of Mechatronic Engineering, Harbin Institute of Technology, Harbin 150001, China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2018年第7期395-400,362,共7页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家自然科学基金项目(51475116)
关键词
并联加载机构
幅相控制
液压系统
正弦位置/力信号
跟踪精度
parallel loading mechanism
amplitude and phase control
hydraulic system
sinusoidal position/force signals
tracking accuracy
