双容水箱的液位控制问题。首先对被控对象的模型进行分析，并采用实验建模法求取模型的传递函数。其次，设计PID控制器，在Matlab/Simulink环境下建立双容水箱控制的仿真模型，对PID控制算法进行仿真研究。通过仿真实验，证明该设计方法可行性和该算法的正确性。最后完成了基于PLC的双容水箱液位控制的软硬件设计，编写了PLC梯形图实现了水箱液位的PID控制。-Dual tank water level control problems. First, the controlled object model for analysis and modeling approach using experimental strike transfer function model. Secondly, the design of PID controller, simulation model dual tank water control in Matlab/Simulink environment, PID control algorithm simulation. Simulation results show that the design feasibility and correctness of the algorithm. Finally completed the hardware and software design of PLC-based dual-tank water level control, the preparation of the PLC ladder to achieve the tank level PID control.