可重构机械系统变形原理与调控方法的研究

【作者】 姬鹏升；

【导师】 范守文；

【作者基本信息】 电子科技大学 ， 机械电子工程， 2009， 硕士

【摘要】 现代机电产品正在变得越来越复杂,这使得机电产品在对功能和性能要求越来越高的同时,对其可靠性和安全性的要求也越来越高。本文以提高机械系统的可靠性和安全性的方法与技术的研究为主线,对可重构机械系统的变形原理、重构方法及其DSP控制的实现技术进行了较为深入系统的研究。可调机构通过对传统机构杆长调节、铰链点的调节来完成多个任务,解决了传统机构任务单一性的问题,同时也为机构的重构容错提供了一条新思路。本文结合球面五杆机构来对可调机构的容错重构进行了研究,由于球面五杆机构具有两个自由度,所以要有确定运动就必须有两个输入,冗余的自由度使球面五杆机构的容错重构成为可能。本文对球面五杆机构容错重构前后的机构进行了仿真分析,并给出了故障重构为球面四杆机构的容错算法,并进行了容错重构后的仿真分析,通过调节铰链点的位置与杆长达到了重构后仍能完成重构前任务的目的。设计了一种具有容错能力的探测车,该探测车可通过冗余关节的重构来实现探测车的变形,可采用轮、腿相结合的策略来完成不同路面状况下的行走任务,并且可以通过重构变形来达到车身宽窄变换以及整车高低变换以适应不同的探测环境。讨论了轮式和腿式两种故障情况下的容错策略,推导了相关的容错重构算法,在ADAMS平台中建立了虚拟样机并进行仿真试验,验证了轮式和腿式两种容错重构规划的可行性,并为探测车的控制提供了理论基础。提出了一种机械系统可重构的混联机床,研究了混联机床机械系统的容错重构策略,提出了基于机构类型演化的机械系统重构容错新方法,给出了球铰演化为虎克铰的实施方案。导出了故障和非故障状态下混联机床的位置反解算法,在ADAMS平台中进行了仿真分析和研究,得到了容错重构前后自旋角的变化曲线以及各驱动腿的长度和工作台位移的变化曲线,仿真结果表明,利用混联机床的机械系统可重构性能可以提高混联机床的可靠性和安全性。研究了基于DSP的机械系统重构策略的控制实现方法,针对可重构机械系统中的直流伺服电机的控制,研究了其PID控制实现方法,以混联机床的一条驱动腿的轨迹跟踪为例,进行了PID控制的仿真和实验研究。更多还原

【Abstract】 Nowadays, electro-Mechanical-Products (EMPs) are getting more and more complex, this brings the growing demands on function and performance with simultaneously growing requirements on reliability and safety for EMPs. This paper takes research on technology and methodology for enhancing reliability and safety of mechanical system as the main clue, transformation principle, reconfiguration method and DSP control technology for reconfigurable mechanical system are studied deeply and systemly in this paper.Adjustable mechanism can realize several tasks by changing length of mechanism bars or position of joints, it presents a new idea for fault-tolerant reconfiguration for mechanism. A fault-tolerant reconfigurable spherical five-bar mechanism is studied in this paper. Because it has two DOFs, this spherical five-bar mechanism offers possibility for fault-tolerant. Simulation analysis is conducted for both normal state and fault state, fault-tolerant algorithm for the spherical five-bar mechanism transforming into spherical four-bar mechanism is deduced. Simulation analysis for spherical mechanism after reconfiguration is done, the spherical four-bar mechanism can continue complete the pre-defined task of the spherical five-bar mechanism by changing the length of bars or position of joints.A new wheel-leg type rover is proposed and designed in this paper, this rover can change its structure by reconfiguration of its redundancy joints, and it can move with wheel-mode as well as leg-mode under different road conditions, by changing configuration, the body of the rover can transform in both width direction and height direction in order to adapt different environment. The fault-tolerant strategies for wheel-mode and leg-mode of the rover are discussed, and related reconfiguration algorithms are deduced, virtual prototype is built on ADAMS desktop, and simulation experiments are carried out.A novel hybrid machine tool(HMT) with mechanical system reconfigurable ability is present in this paper, fault-tolerant reconfiguration strategies for HMTs are studied, a novel fault-tolerant reconfiguration approach for mechanical system faults of hybrid machine tools is proposed based on mechanism type transformation, implementation strategy for spherical joints transforming into huke joints is given. Inverse displacement analysis algorithms are deduced for both fault and non-fault status of HMTs, simulation analysis and research are conducted based on ADAMS desktop, self-rotation angle curve as well as joint space trajectory curves for before and after reconfiguration are obtained, simulation results show that the safety and reliability of HMTs can be enhanced utilizing the reconfiguration characteristics of mechanical systemImplementation method for mechanical system reconfiguration based on DSP controller is studied in this paper. Aiming at DC servo motor control of reconfigurable mechanical system, a DSP based PID controller is presented, taking the trajectory tracking control of one driving leg of HMTs as an example, related simulation and experiment researches are conducted.更多还原