摘要
为了满足复杂农林环境下植保作业需求,提出了一种纯液压驱动力的植保农药喷雾机柔性底盘系统;针对底盘四轮驱动所采用的阀控马达非线性控制系统,建立状态方程,采用李亚普诺夫理论进行了系统稳定性分析,采用蒙特卡洛模拟法进行了系统可靠性预测及优化。结果表明:该液压控制系统是稳定的,其可靠性较高,优化后的系统可靠度均值为0.89,平均无故障工作时间预测值为8 526 h,远高于底盘1 a内实际工作时间2 160 h;采用AMESim软件对该液压控制系统进行了建模和仿真,并与样机实验结果进行了对比,当PID控制器参数KP=0.5、KI=4、KD=0时,系统稳定性较高,响应迅速,2.5 s后达到稳定状态。车轮加速度响应曲线有小幅波动,振荡次数在2次以内;负载干扰力矩从1 Nm增大到20 Nm时,马达转速输出曲线几乎重合。研究结果表明阀控液压马达动力系统鲁棒性好,其稳定性和可靠性可满足底盘需求。
A flexible chassis system with full hydraulic driving was put forward in order to meet the demand of plant pro.tection practice under the complex agricultural and forestry environments. For the nonlinear hydraulic control system of the four.wheel driven chassis through valve.controlled hydraulic motors, the state equation of the system was established. The system stability was analyzed with Lyapunov theory, and the Monte Carlo simulation method was used for system re.liability prediction and optimization. Results showed that the hydraulic control system was stable and the reliability was high. The mean reliability value was 0. 89 after optimization and the forecast value of the mean time before failure was 8 526 h, which was far above the work time of 2 160 h within a year for the chassis. The AMESim software was used for modeling and simulating the hydraulic control system and the results were compared with prototype experiment results. The results showed the system stability was high when PID controller parameters was set as KP=0.5,KI=4,KD=0. At the above conditions, system response was quick and system reached stable state after 2. 5 seconds. There were slight fluctuations in the wheel acceleration response curve. But the oscillation frequency was within 2 times. The output curves of motor speed were almost overlapped when load disturbance torque was increased from 1 Nm to 20 Nm. This demonstra.ted that the robustness of hydraulic system was good and its reliability and stability met the chassis demand.
出处
《南京林业大学学报（自然科学版）》
CAS
CSCD
北大核心
2015年第3期137-142,共6页
Journal of Nanjing Forestry University：Natural Sciences Edition
基金
国家林业公益性行业科研专项项目(200904051)
中越政府间科技合作联委会长期交流项目(8-05J)
江苏省科技支撑计划-农业高技术专项(BE2012383)
江苏高校优势学科建设工程资助项目(PAPD)
江苏省2013年度普通高校研究生科研创新计划项目(CXZZ13_0536)
安徽科技学院2013年度校级重点科研项目(ZRC2013364)
关键词
柔性底盘
阀控马达液压动力
非线性系统
稳定性
可靠性
flexible chassis
valve-controlled hydraulic motor power
nonlinear system
stability
reliability
