| Automated Guided Vehicle(AGV)is an automatic transportation vehiclewithout driver. With a certain amount of weight, it can travel between the departureand the destination.AGV is the key equipment of automatic material flow system and flexiblemanufacturing system. Today, AGV is widely used in various fields such asmanufacturing, storages, libraries, ports, airdromes, tobaccos, a medications,dangerous work spaces, foodstuffs, chemical plants and material flow center and soon in developed countries. With the development of economy in China, someenterprises also start to apply AGV now. Especially AGV of low cost and mini-typebecomes more and more popular.There are two kinds of steering systems: typical driving steering system andglobal driving steering system. Typical driving steering system mainly has threeshapes: front-wheel steer and drive, front-wheel steer rear-wheel drive, two wheelsdifferential and so on. Based on reducing cost and miniaturization, this paperdesigns a new kind of driving and steering mechanism. The mechanism uses onlyone dynamotor, along with the electronic magnet clutch to realize driving andsteering functions.AGV is mainly guided by the embedding thread, machine vision, laser and soon. each one has its advantage and disadvantage. This paper adopts a kind ofmagnetic inductive guiding methods, which uses array approaching-switches toinduce metal strips. The features of the navigation method are as follows: lowercost, easily paving paths, easily changing paths, limiting applied sites, lowerguiding precision.Aiming at the model vehicle based on this new kind of driving and steeringsystem, along with magnetic inductive navigation, this paper proposes PID steeringnavigation controller, and then designs intelligent PID controller, and do someexperiment validation. Experiments results show that vehicle navigation control isaccurate and reliable. Do some kinematics analysis and modeling;get thetransferring parameters of the driving steering system through experiments,integrate kinematics model and the transferring function to get the state equation ofthe steering control system. Design the optimal controller. Simulation experimentsshow that the optimal controller has good performance and good anti-disturbanceability.Now introduce the main contents of this paper: 1. Design the experimentmodel vehicle based on driving and steering integration mechanism;2.Demonstrate particularly the driving and steering principle of this kind ofmechanism which incorporates driving and steering together. Then analyzes brieflythe two steering control from the view of kinematics and dynamics. 3. Propose anelectronic magnetic induction navigation method;analyze its advantages,disadvantages and the choice of parameters. Introduce the recognition algorithm oflinear navigation. 4. Design the PID controller and intelligent PID controller of themodel vehicle. 5. Do the kinematics modeling of the model vehicle, get thetransferring parameters of the driving steering mechanism, then design theoptimization controller;6. Write the model vehicle controlling program which hasgood person-mechanism interface, and do some navigation and controlexperiments.1. Design and manufacture the model vehicle which has driving and steeringintegration mechanism;and this set a foundation for the principle research andexperiment validation.This paper tries to adopt a new kind of driving steering integration mechanismto realize the driving and steering of AGV, design and manufacturing the modelvehicle which adopts this mechanism. The model vehicle mainly consists offollowing parts: driving and steering system, the whole mechanism of the modelvehicle, the electronic subsystem, sensor subsystem, computer measure and controlsubsystem and the choice of main technique parameters.2. Demonstrate particularly the driving and steering principle of this kind ofhinge jointing mechanism which incorporates driving and steering together. Thenanalyze its advantages and disadvantages, aiming at the model vehicle that basedon the mechanism, propose two steering control strategies, and then analyze thecharacteristics of the two steering control strategies by using the dynamics andkinematics.3. Demonstrate the navigation principle of the model vehicle, providesautomatic navigation information using electronic magnetic induction method. Itsrecognition sensor is approaching-switch series which takes on arrays. Analyze theadvantages, disadvantages and the parameters choice of the method. Particularlyintroduce the recognition algorithm and the flow of linear navigation.4. Design the steering PID controller and intelligent steering PID controller ofthe model vehicle, and do some experiment. The input information of PIDcontroller contains two parts: the lateral deviation information of the hinge jointpoints and the orientation deviation information of the front part of the modelvehicle. Because the PID controller is single input, we have to fuse the twodeviation. Both experiments results and principle analysis show that the coefficientof deviation is related with the velocity of the vehicle. Based on the influence thatthe parameters to the system dynamic performance, through many experiments wechoose a suit of optimal PID parameters and optimal addition function, experimentshows that the controller can realize navigation. At the same time, we find thatwhen the variances are different, it need different PID controller, so we designintelligent PID controller. According to related adjusting rules and according todifferent variance information, adjust the three parameters and the output of PIDcontroller, experiments show that the controller has good performance.5. Establish the mathematics model of the model vehicle, design the steeringoptimal controller of the model vehicle, and do computer simulation validation.Based on this special kind of driving and steering method, found its kinematicsmodeling, analyze the static and dynamic characteristic of the driving and steeringsystem. Then get the transferring function of the driving system throughexperiments, thus cooperate with kinematics modeling we can get the stateequation of the steering control system. The analysis has been done tocontrollability, observability and stability of system. Analysis results show that thesystem open cycle is not steady. Yet the system is controllable and observable, so itmay become closed loop steady by means of the pole configuration. Because it isthe linear time invariant system ( LTI ),the paper choose the linear quadratic formoptimal controller design scheme in the contemporary control theory by applyingthe modern optimal control theory. By means of analysis to step response diagramand poles diagram of the closed loop system, the matrixes Q and R that representthe weight of control process and control expense are fixed reasonable. And thenobtain the optimal state feedback array K, and finish design of optimal controller ofAGV. Simulation and experimental results show that the designed controller canrealize accurate and stable navigation control and it has the well steady-statecharacteristic and adaptability to the changes of speed. At the same time, it alsovalidates the above mathematical model of the control system. The steering modelof the system is deducted correct.6. Develop the model vehicle controlling application system which has goodMan-machine Interface, and do some navigation and control experiments.Based on Windows 98 operating system, develop the model vehiclecontrolling application system using VC++. The control software consists ofseveral parts as follows: navigation information and disposing part;vehicle controlpart;vehicle state controlling part and users input and display part.The controlling application system accomplishes all of the controllingarithmetic function. Do the linear navigation experiments. The experiment showsthat the software has good performance, the arithmetic is effective, and all the partsare reliable. |
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