【作者】 杨文超；

【导师】 张荣标；

【作者基本信息】 江苏大学 ， 控制理论与控制工程， 2006， 硕士

【摘要】 PID控制是工业过程控制中被广泛采用的一种控制方法。在计算机技术普及的今天，PID控制技术得到了进一步的完善。基于微处理器的数字PID控制器改变了传统模拟PID控制器参数整定不灵活的问题。但是常规微处理器容易在环境恶劣的情况下出现程序跑飞，如果实现PID算法的微处理器因为干扰或其他原因而出现故障，会引起输出值的大幅度变化或停止响应。这种情况往往是生产实践中所不允许的，在某些场合还可能造成严重的生产事故。 基于FPGA设计的PID控制器，在其运行之初由外部微处理器提供PID参数的整定信息，保留了参数灵活整定的特点。一旦PID参数整定完成便处于独立运行状态，不再受微处理器的影响，以最大限度地克服了通过编程实现PID控制器的缺点。另一方面由于采用FPGA技术，控制器具有比普通微处理器更宽的采样处理速度范围。为了利于一些改进算法的实施，采用位置式PID算法进行设计，并给出了积分分离算法的解决方案。 采用FPGA实现PID控制器，实际上是利用数字逻辑电路来完成PID控制，由于PID控制算法运算工作量大，增加了实现的难度，尤其是其中的运算精度与溢出问题。为了确保运算过程有足够的精度，必须采用浮点运算。在技术上针对具体参数特点采用不同的浮点表示方法，并提出了相应的对阶措施。既保证了运算精度又节省了FPGA硬件资源。 运用自上而下的设计理念，把整个设计分成求偏差量、比例、积分、微分、移位对阶和时序协调控制等几个部分，对电路中的每一块都进行了RTL级的实现，同时进行严格的仿真验证，并进行了速度性能分析。本成果封装后还可作为一个专用的IP核供设计更大控制系统时复用。更多还原

【Abstract】 PID control method is widely used in industrial processing control. Today when computer technology be widely used, PID control method gains farther development. The PID controller based on microprocessor solved the problem that the parameter cann’t be change flexibly in traditional analog PID controller. But the general microprocessor has a limit of blind running when placed in atrocious condition. If the microprocessor which implements PID arithmetic break down for disturbance or other reasons, it will cause the output value change a lot or stop response. This circs is not allowed in productive practice, even cause severe productive accident.The PID controller based on FPGA receive the information of setting parameter at the beginning of its running, which is provided by external microprocessor.Thus, the characteristic that PID parameter can freely be adjusted is reserved. Once parameter adjusting complete, the PID controller run independently and will not affected by microprocessor. So the shortcoming that using programme to realize PID control algorithm is overcame farthest. On the other hand, due to the technology of FPGA, the controller has wider range in sampling calculate speed. In order to be propitious to bring some modified algorithm into effect, the positional PID control algorithm is selected, and the integral separation algorithm was designed as an example.Using FPGA to design PID controller is to implement PID control by digital logic circuit. Due to the large operation workload of PID control algorithm, the difficulty to realize algorithm rise, especially when deal with the problem of precision and overflow. In order to ensure the precision of operation, floating point number calculate scheme is obligatory. Technically, aim at the characteristic of each parameter, use different floating point scheme and put forward relevant means to adjust rank. Consequently, the resource in FPGA can be saved and the calculate precision also be ensured.According to top-down designing conception, the whole circuit is divided into several parts, such as calculate amount of dispersion module, proportion module, integral module, differential module, alignment rank module and time sequence control module. Every module in the circuit is carry out by RTL level language. And the function of every module in circuit is validated by emulation. At last, the designed circuit’s speed performance is analysis. After encapsulation the PID controller becomes a IP core. It can be used to build lager system.更多还原