【正文】 so on merit auto safety control is in the convention brake system foundation advanced version technology,separable mechanical and electronic formula two kinds. On the modern automobile installs the antilock braking system massively,ABS both has the automobile sill to change under the stopping,guaranteed that automobile39。s glide rate,the automatic control function on wheel39。s glide rate control in certain scope,use fully between the tire and the road surface adhesion,reduces the stopping distance effectively,obviously enhances when the car braking controllability and stability,when each kind of traffic accident which has avoided the wheel hugs dies easy to with brake intensity39。rdoes not have time the ground braking force wheel rolling radius。s angular speed. 西安工程大學畢業(yè)設計英文譯文 2 Longitudinal and the lateral adhesion coefficient may express for the wheel slip rate is called critical point of fixity fast the pace according to the control theory is smaller than the SK region is called the stable brake area,wha SK later has custommade unstable moves the is precisely uses between the path and tire39。s level. 2. Conrtol technology used by ABS now The ABS control effect is decided control technology[4]which to a great extent uses in the present uses is mainly the logical threshold value control further enhance ABS the performance,but also proposed some based on the glide tate control technology,like the PID control,the glide modality change the srtucture controls,fuzzycontrol and so kind of control approaches the expectation by the different control rule the spot. PID controls The definition expects glide rate S0 and difference of the actual glide rate S for e=SS0,then the PID control rule may be represented as: 西安工程大學畢業(yè)設計英文譯文 3 Therefore,the ABS controller39。s glide rate to approach hypothesis goal S0 by the quickest way. The glide modality changes the structure control Against holds the dead brake by the automobile basic principle to be possible to know,its brake process39。s glide tate control in coefficient of adhesion peak point SK,then the glide modality changed structure basis system condition,the deviation and the derivative value then,in the different controlled area,by perfect switch39。s size and the mark,the guarantee system in the glide region very small scope,the state point locus(S,*S)along moved the festival curve to slide slippery to the control objective(SK,0). Usually takes the braking moment for controlled variable U,the cut condition is: And Mb,Mb+ represent the braking moment which decided by the governing system to reduce,to increase two different conditions separately. For the cut function,e=SSk is the actual glide rate telative target point devivation. Fuzzy control Regarding take the glide tare as controlled member39。s rate of change EC,the output for the brake line flowing tubing head the belt modification factor the fuzzy controller,uses the control list summary which the fuzzy reasoning algorithm forms is an analysis formula: And Alpha is the modification factor,Alpha the value size has reflected directly to 西安工程大學畢業(yè)設計英文譯文 4 the deviation and the debiation rate of change weighting the adjustment modification factor Alpha,may change the control Alpha is big,indicated that is big to deviation39。When Alpja is small,the control goal reduces the over modulation,but the response process is uses the belt two Alpha values the modification factor exptessions to be able to request on the satisfiability,namely: u =α X E + (1α )EC And,modification factor α1,α2 in (0,1). Logical threshold value control This method establishes some control limit advance to certain controlled variable(threshold)the value,when applies the brake,according to the putation realtime parameter value and the corresponding threshold value39。s state of motion,thus the control adjustment brake pressure,gains enough big brake intensity and the good yawing includes as the ABS controlled variable:Wheel skidding rate S,the wheel rotates the angle adds(reduces)the speed Omega and the rate of and so on three kind of descrimtion wheel movement situation or danamics condition only uses a controlled variable difficulty with to guarantee that ABS has the good performance under each kind of travel condition,therefore,the logical threshold value control method rotates at present the wheel the angle adds(reduce)the speed to take the primary control parameter,but takes wheel39。s velocity,calculates the reference glide rate,has the difference with the actual glide rate. Double parameter control Double parameter control39。s braking force again through the solenoid kind tows the fast sensor monly used Doppler velocity the automobile goes the Doppler radar antenna by certain frequency to the earth launching electromagic wave,simultaneously receives the electromagic wave which unceasingl