Study On The Simulation Of Anti-lock Braking System Of The All-terrain Mobile Crane

All-terrain mobile crane has the features of mobility, quickness for operationand easy access to load, to adapt to the variational operation situations. Foradapting quickly transfer on the highway and keeping the vehicle's drivability, itmust have the higher braking function, but the conventional braking system usuallycan not meet the requirements. In order to insure the stability, safety and reliabilityof the mobile crane while braking, installing Anti-lock braking system is the mosteffective measure.Anti-lock braking system which is based on the conventional control system isa kind of electrical-mechanical system, which can regulate the wheel's brakingforce automatically, prevent the wheels from locking and balance braking force.The device is significant to steering safety. It can raise the direction stability,shorten the braking distance, reduce the wearing of the tyre, increase the servicelife of the tyre and the average speed of the automobile etc..The domestic research of ABS has been included in the Science andTechnologies Development Program since "the 9th Five-year Plan", many highschools, companies, research branches sign the project to do the research and haveobtained certain results, currently the domestic ABS has developed to the road-teststage, but most of them are for the 2 axes vehicle, such as car and passenger car etc.in fact, the research on ABS for the all-terrain mobile crane has gotten behind inthe foreign advance in the same kind of products.All kinds of data show that the domestic research of ABS for the all-terrainmobile crane is not much, this paper contrasts the research in this field for the car,puts the emphases on the all-terrain mobile crane of 200ts. Combining thecharacteristic of the all-terrain mobile crane, such as long bodywork, high load andABS usually stops working automatically when the vehicle's speed is much loweretc. Then the paper mainly studies the braking condition which all-terrain mobilecrane is on the beeline road.The paper sufficiently thinks of the load transfer of the axes and the breaksituation of the road surface, builds the relevant simple models, including thewhole automobile model, the single wheel model, the tyre model, the brakingsystem model, the road surface model. Combining the main method and strategiesof current ABS research, the controller models of ABS are established. The paperplaces great emphasis on the logic gate value control and fuzzy control. Thecontrollers of ABS are established with the stateflow model and the Fuzzy toolboxof matlab/simulink software. ABS are developed under the corresponding relationwith imports and exports, at the same time, the models are simulated and studiedwith the changes of the road, first speed, load of axes, wheel inertia etc. Accordingto the results of lots of situations of simulations and the analysis of the influence ofthe factors, the paper summarizes a series of control regulations of the system ofABS.Anti-lock braking system which is based on controlling of the logic gate valueadopts the stateflow model and builds the controllers of ABS on the different road.The vehicle is simulated on the same road surface with the different first speed andon the different road with the same first speed. The paper summarizes the influenceof the changes of the first speed, the road surfaces and the logic gate value for ABS.Anti-lock braking system which is based on the fuzzy controlling adopts fuzzy toolbox of the simulink software and builds the fuzzy controller, the controller of theselection of the road surface is build by the stateflow model. The changes of thecontrol rules, proportional parameters are summarized for the influence of thecontrol rules of ABS. The vehicle is simulated on the different road and the breakroad with the same first speed. At the same time the contrast is brought forward bythe simulation with two different controllers.Anti-lock braking system which is based on controlling of the logic gate valueand which is based on the fuzzy controlling can keep the reasonable speed of thewheels in the expected location when the vehicle is braked, so the wheels can getthe big enough inserted force which is from the ground and the vehicle can keepthe better braking efficiency. The whole braking process which is based on thefuzzy controlling is smoother than which is based on controlling the value of thelogic gate, the fuzzy controller owns more adaptability.When the vehicle is braked on the same road with the different speed, we canget the simulation results by the software of matlab. The braking time and thebraking distance will be shortened when the first speed is lower. When the vehicleis braked on the different road with the same speed, the braking time and thebraking distance will be shortened when the friction quotiety of the road is higher.Besides, we should select the different parameter with different speed, the higher ofthe first speed, the bigger of the selected parameter. When the vehicle is braked onthe different road with same speed, we need select the reasonable controller andcontrolling rules. The lower value of logic gate is selected when the vehicle isbraked on the road surface which offers lower friction, then the higher value oflogic gate is selected when the situation is opposite. If the road surface is changedsuddenly when the vehicle is braking, the speed of wheels will fluctuate obviously,then it becomes smoothly and braking force is strengthened.When the braking force is higher or lower, it cann't easily reach the biggestvalue of the force which is offered by the road surface, making the result worse,therefore, the vehicle's braking time, braking distance and slip ratio's fluctuantscope are relevantly increased;so the wheels are locked easily and the brakingdistance is increased;Along with turn the increment of used to move the quantity,slip ratio's fluctuant scope, the time and the distance contain augmentative trend;When the time of the electromagnetism is delayed, the braking time and distanceare increased;The changes of the vehicle load hardly influence the simulationresults. The braking time and distance can be cut down when the vehicle load isincreased, because the ground can offer much more braking force. On the contrast,the braking time and distance will increased when the vehicle load is cut down.