客车用定速巡航系统

汽车巡航控制系统具有高度非线性、时变不确定性及存在噪声和负载扰动等因素的影响,因此探索采用模糊自适应PID（比例、积分、微分）控制器来解决这些问题。     

交互式水域环卫机器人的避障路径规划算法

为使交互式水域环卫机器人（Interactive Water Sanitation Vehicle，IWSV）在进行垃圾收集时成功捕获水中浮动垃圾并顺利规避水域障碍物，提出一种将基于采样的快速搜索随机树（Rapidly-exploring Random Tree，RRT）算法与速度障碍模型相结合的路径规划算法。利用双目摄像头基于视差定位法获取水域动态障碍物的位置坐标，利用IWSV搭载的感应元件获取其自身与障碍物的相对方位角，基于速度障碍法计算可成功避开障碍物的移动角度调整范围，对更优的RRT*算法中的随机采样过程进行进一步优化，得到改进的避障路径规划算法。考虑实际应用场景，引入抗积分饱和比例积分微分控制（Proportional Integral Differential Control，PID Control）法使航向控制器的控制效果更为精准有效。在实景测试时避障路径规划算法存在稳健性，基于到达时间（Time of Arrival，TOA）定位法进行仿真分析。仿真试验结果表明，该路径规划算法比RRT算法和改进前的RRT*算法路径规划效果更优，可靠性更好，可在较短时间内避障并得到较优移动路径。在实景测试时基于TOA的Chan算法更加符合定位估计需求，且IWSV本体感应装置的噪声测算宜在10 m以内。     

Intelligent VIV control of 2DOF sprung cylinder in laminar shear-thinning and shear-thickening cross-flow based on self-tuning fuzzy PID algorithm

A self-tuning fuzzy PID (ST-FPID) control scheme is implemented within a joint interactive (Matlab/Simulink/Fluent) co-simulation framework for effective two degrees of freedom (2DOF) vortex-induced vibration (VIV) control of an elastically-mounted circular cylinder in laminar cross-flow of incompressible non-Newtonian power-law fluids based on the control action of a single transverse force actuator. The model-free controller, which systematically tunes the control parameters online in real time based on given rules, is well-known to be highly advantageous over the previously employed conventional PID controllers. It is particularly capable of handling the intricate non-linear dynamic effects inherent in the complex fluid rheology of non-Newtonian flow past the cylinder in presence of unmodeled system dynamics, high parametric uncertainties, diverse operational conditions, and time-varying external disturbances and control signals. Extensive numerical simulations reveal that the complex shear-thinning and shear-thickening behaviors of fluid viscosity can substantially influence the cylinder dynamic response, applied hydrodynamic forces, and flow structure. In particular, effectiveness and high performance of the adopted ST-FPID control strategy in substantial suppression of the high amplitude coupled 2DOF VIV of the elastically-mounted cylinder at selected critical reduced velocities in the lock-in region are established for a wide range of power-law index parameters (e.g., up to 83% reduction in RMS value of cylinder cross-flow displacement and up to 35% reduction in RMS value of cylinder in-line displacement for n=1and U* = 5 at Re = 100). Also, the vigorous action of the error-driven ST-FPID controller in forcing the high strength vortex shedding patterns of the uncontrolled cylinder out of the lock-in condition into the classical von Kármán vortex street of 2S-type mode of moderately weaker strengths is verified.