VB中利用MIODBUS协议实现通信

工业控制器连网为现场的控制管理提供了方便，在众多的工业网络控制协议中，Modbus就是其中的一种，在国外得到了广泛的应用，而在国内的控制器中用的较少。由于其实现的简单性，可以很方便地实现在各种开发环境中的通信，本文在介绍了MODBUS协议的基础上，给出了在Visual Basic中进行MODBUS协议串口通信的范例。     

MODBUS协议在电动轮自卸车控制与故障诊断系统中的应用

对MODBUS协议的技术要点和具体规定作了比较详细的阐述。根据电动轮自卸车拉制与故障诊断系统的通信需求,确定电动轮自卸车控制与故障诊断系统的通信方案,研究并实现基于MODBUS协议的电动轮自卸车控制与故障诊断系统的通信模块。     

用MODBUS实现触摸屏与单片机的通信

讲解如何利用MODBUS通信协议,实现触摸屏与单片机的通信和控制。详细介绍了触摸屏与单片机的硬件连接、软件设置及编辑、MODBUS通信协议的使用方法等内容。     

MODBUS／TCP主站协议栈的改进

在使用MODBUS／TCP协议通信的过程中,主站读写命令与从站响应的速度不匹配,会引起主站的应用程序等待;同时由于数据收发过程处理不当,容易导致通信异常中断。为解决这两个问题,在分析MODBUS／TCP协议栈实现的基础上,通过增加内存缓冲区和管理模块,提出了一种MODBUS／TCP主站协议栈的设计和实现方法。该协议栈有效缩短了主站应用程序的读写等待时间,提高了数据通信的稳定性。     

MODBUS协议下集散控制系统串行通信研究

为了更好地利用集散控制系统实现工业网络监控,对MODBUS协议下集散控制系统串行通信机理与方式进行了详尽研究,从实际运用看,基于MODBUS协议的网络监控是实现小型工业网络监控的好方式。     

MODBUS协议下集散控制系统串行通信研究

为了更好地利用集散控制系统实现工业网络监控,对MODBUS协议下集散控制系统串行通信机理与方式进行了详尽研究,从实际运用看,基于MODBUS协议的网络监控是实现小型工业网络监控的好方式.     

基于MODBUS RTU通信协议下的CRC算法实现

MODBUS协议是应用于电子控制器上的一种通用协议，通过此协议，控制嚣相互之间、控制器通过网络（例如以太网）和其它设备之间可以通信。如今MODBUS RTU协议已经成为我国工业自动化网络协议规范的国家标准之一。本文详细讨论了遵守MODBUS RTU协议的传输数据的CRC算法验证实现。     

利用MODBUS提高多CPU系统协同开发的效率

提出利用MODBUS协议实现多CPU系统中信息交互的方案,分析了软硬件通信机制的设计和系统协同开发的方法,以及各种提高通信效率的措施。     

“可编程序控制器及其应用”讲座：第十六讲 网络控制和工业通信系统

本讲以美国GOULD公司1978年推出的MOD-BUS网络为例,介绍工业通信系统的硬件构成类型、通信协议和应用注意事项等。一、MODBUS简介 MODBUS网络是一个工业通信系统,由带智能终端的可编程序控制器、计算机以及共用线路或专用线路组成。 MODBUS系统可应用于各种数据采集和过控监控,包括:能源管理和环境保护;安全检测;过程控制;数据采集管理和记录;产品检验;质量管理;管道管理和控制;传输线和传输机械的控制;机床控制等。     

MODBUS协议在光伏并网系统中的应用

设计了一套光伏并网系统,该系统包括逆变模块和人机接口模块,通过MODBUS协议来实现两个模块的通信.给出了系统的硬件结构图,分析了MODBUS协议的特点,详细介绍了协议的软件实现,列出了关键部分代码.     

New type of controller: the proportional integral minus delay controller

In the design of a control system, the derivative controller is often required to obtain a quick response. However, when the control system is subject to noise inputs, the functioning of the derivative controller may be jeopardized owing to its sensitivity to high-frequency noise. In order to overcome this problem, a new type of controller, called the proportional-integral-minus-delay (PIMD) controller is proposed in this paper. It is shown that in addition to exhibiting almost the same characteristics as the conventional proportional-plus-integral-plus-derivative (PID) controller, the PIMD controller is less sensitive to high-frequency noise. It seems that an appropriate PIMD controller would be a good replacement for a PID controller. The output time responses of the closed-loop system with a PIMD controller and the frequency-response characteristics of a PIMD controller are obtained by computer simulation.     

具有H_∞跟踪性能的机器人自适应PID控制

针对非线性不确定机器人系统的轨迹跟踪控制问题,提出一种鲁棒自适应PID控制算法.该控制器由主控制器和监督控制器组成.主控制器以常规PID控制为基础,基于滑模控制思想设计PID参数的自适应律,根据误差实时修正PID参数.基于Lyapunov函数设计的监督控制器补偿自适应PID控制器与理想控制器之间的差异,使系统具有设定的H_∞的跟踪性能.最后,两关节机器人的仿真实验结果表明了算法的有效性.

Abstract：

A robust adaptive PID control algorithm is proposed for trajectory tracking of robot manipulators with nonlinear uncertainties.The controller is composed of a main controller and a supervisory controller.The main controller is designed based on the traditional PID controller.The parameters of the PID controller are updated online according to the system running errors with the adaptation law based on the sliding mode control.The supervisory controller is proposed to compensate the error between the adaptive PID controller and the ideal controller in the sense of the Lyapunov function with the specified H_∞ tracking performance.Finally, the simulation results based on a two-joint robot manipulator show the effectiveness of the presented controller.     

Study of Learning Fuzzy Controllers

This paper compares two types of learning fuzzy controllers, the self-organizing fuzzy (SOF) controller and the hybrid self-organizing fuzzy proportional–integral–derivative (SOF-PID) controller. The SOF is an extension of the rule-based fuzzy controller, with additional rule creation and rule modification mechanisms. The hybrid SOF-PID comprises the SOF as a learning supervisory controller readjusting the proportional gain of the PID controller at the actuator section, when the system is on line. The structures of the SOF controller and the hybrid SOF-PID controller are studied. The performances of the SOF controller and the hybrid SOF-PID controller are compared by applying them to a two-link non-linear revolute-joint robot arm. For the path tracking experiments, the hybrid SOF-PID controller followed the required path more closely and smoothly than the SOF controller. The results of the experiments for the SOF controller and the hybrid SOF-PID controller are also compared with those obtained with a conventional PID controller, using the same values supplied at the setpoint.     

基于逆系统方法的综放工作面控制系统的模糊控制器

对逆系统方法作为反馈线性化方法及其非线性本质进行深入的研究后,认知到逆系统方法建立的模糊控制器是一种变增益的非线性控制器,它与PID控制器有许多相似之处,进而设计出模糊PID复合控制器。模糊PID控制器在综放工作面中的应用的关键是模糊控制器的各个参数的整定。因此,我们用传统的方法首先设计一个PID控制器,在稳定时使模糊PID控制器的参数与PID控制器的对应参数相等,逐步调节、修改各个参数,从而可以得出模糊PID控制器的参数,模糊PID控制器在煤矿综放工作面上运用的结果令人满意。     

拟合迭代学习数据的工业过程控制器

为进一步提高工业过程控制系统的跟踪能力, 实现稳、准、快等性能, 本文利用迭代学习算法产生的各类信息, 在控制器函数拟合的基础上, 设计了一种高精度跟踪的鲁棒控制器. 首先在频域对闭环迭代学习算法进行分析, 得出迭代学习控制器等同于级联控制器的结论, 进而采用一个低阶结构的控制器去拟合误差序列与控制序列,避免了难以物理实现的高阶控制器, 最后通过对一般的工业过程对象进行实验设计, 结果表明这种控制器在快速性、无超调及控制精度上具有很好的优势, 并且具有良好的抑制干扰能力.     

模糊控制器的实时精确算法与优化设计

将T-S型模糊控制器与PID控制器相结合,提出了TS-PID模糊控制器模型。推导出了输入采用正规模糊集、三角形全交迭隶属度函数的典型TS-PID模糊控制器的插值解析表达式,揭示了TS-PID模糊控制器本质上是一种非线性PID控制器,为实际应用提供了一种快速精确的控制算法。基于该插值表达式,进一步探讨了利用遗传算法对TS-PID模糊控制器进行优化设计的方法。     

具有加权因子的PID型模糊控制器分析及设计

为了降低模糊控制器的设计难度, 提高控制性能, 以二维模糊控制器为基础, 设计了一种具有加权因子的PID型模糊控制器, 并提出了基于普通PID控制器参数整定模糊控制器参数的方法。首先, 基于模糊控制器的解析结构推导, 从理论上证明了该类PID型模糊控制器是一个全局二维多值继电器与一个局部具有变结构PID控制器的组合; 然后, 基于平衡点处该类PID型模糊控制器与普通PID控制器之间的等效关系, 建立了模糊控制器系统化的参数设计方法; 最后, 仿真实验验证了本设计的有效性。     

Design of a hybrid fuzzy logic proportional plus conventionalintegral-derivative controller

Presents approaches to the design of a hybrid fuzzy logic proportional plus conventional integral-derivative (fuzzy P+ID) controller in an incremental form. This controller is constructed by using an incremental fuzzy logic controller in place of the proportional term in a conventional PID controller, By using the bounded-input/bounded-output “small gain theorem”, the sufficient condition for stability of this controller is derived. Based on the condition, we modify the Ziegler and Nichols' approach to design the fuzzy P+ID controller. In this case, the stability of a system remains unchanged after the PID controller is replaced by the fuzzy P+ID controller without modifying the original controller parameters. When a plant can be described by any modeling method, the fuzzy P+ID controller can be determined by an optimization technique. Finally, this controller is used to control a nonlinear system. Numerical simulation results demonstrate the effectiveness of the fuzzy P+ID controller in comparison with the conventional PID controller, especially when the controlled object operates under uncertainty or in the presence of a disturbance     

基于反步法的移动机器人鲁棒跟踪控制

以四轮移动机器人为研究对象,建立了机器人完整的数学模型,包括运动学模型、动力学模型以及驱动电机模型。在机器人数学模型的基础上,采用反步法的思想设计具有全局收敛特性的鲁棒轨迹跟踪控制器,设计中考虑了驱动电机模型使控制器更符合实际控制要求,并将其分解为运动学控制器、动力学控制器以及电机控制器三部分,降低了控制器设计的难度。构造了系统的李雅普诺夫函数,证明了该类型移动机器人在所得控制器作用下,能实现对给定轨迹的全局渐近追踪。仿真实验结果表明基于反步法的控制器是有效的。     

A fuzzy logic based supervisory hierarchical control scheme for real time pressure control

This paper describes a supervisory hierarchical fuzzy controller （SHFC） for regulating pressure in a real-time pilot pressure control system. The input scaling factor tuning of a direct expert controller is made using the error and process input parameters in a closed loop system in order to obtain better controller performance for set-point change and load disturbances. This on-line tuning method reduces operator involvement and enhances the controller performance to a wide operating range. The hierarchical control scheme consists of an intelligent upper level supervisory fuzzy controller and a lower level direct fuzzy controller. The upper level controller provides a mechanism to the main goal of the system and the lower level controller delivers the solutions to a particular situation. The control algorithm for the proposed scheme has been developed and tested using an ARM7 microcontroller-based embedded target board for a nonlinear pressure process having dead time. To demonstrate the effectiveness, the results of the proposed hierarchical controller, fuzzy controller and conventional proportional-integral （PI） controller are analyzed. The results prove that the SHFC performance is better in terms of stability and robustness than the conventional control methods.