一、速度控制算法:首先定义速度偏差-50 km/h ≤e (k )≤50km/h ,-20≤ec (i )= e (k )- e (k-1)≤20,阀值e swith =10km/h设计思想:油门控制采用增量式PID 控制算法,刹车控制采用模糊控制算法,最后通过选择规则进行选择控制量输入。
选择规则:e (k )<0 ① e (k )>- e swith and throttlr_1≠0 选择油门控制② 否则:先将油门控制量置0,再选择刹车控制 0<e (k ) 先选择刹车控制,再选择油门控制 e (k )=0 直接跳出选择刹车控制:刹车采用模糊控制算法1.确定模糊语言变量 e 基本论域取[-50,50],ec 基本论域取[-20,20],刹车控制量输出u 基本论域取[-30,30],这里我将这三个变量按照下面的公式进行离散化:)]2(2[ba x ab n y +--=其中,],[b a x ∈,n 为离散度。
E 、ec 和u 均取离散度n=3,离散化后得到三个量的语言值论域分别为:E=EC=U={-3,-2,-1,0,1,2,3}其对应语言值为{ NB,NM,NS,ZO, PS,PM,PB } 2.确定隶属度函数E/EC 和U 取相同的隶属度函数即:E EC U(,5,1)(,3,2,0)(,3,1,1)u (,2,0,2)(,1,1,3)(,0,2,3)(,1,5)g x trig x trig x trig x trig x trig x g x ∧∧--⎧⎪--⎪⎪--⎪=-⎨⎪-⎪⎪⎪⎩说明:边界选择钟形隶属度函数,中间选用三角形隶属度函数,图像略实际EC 和E 输入值若超出论域范围,则取相应的端点值。
3.模糊控制规则由隶属度函数可以得到语言值隶属度(通过图像直接可以看出)如下表: 表1:E/EC 和3.模糊推理由模糊规则表3可以知道输入E 与EC 和输出U 的模糊关系,这里我取两个例子做模糊推理如下:if (E is NB) and (EC is NM) then (U is PB) 那么他的模糊关系子矩阵为:1211U EC E R R R R ⨯⨯=其中,711)0,,0,5.0,1(0⨯==ΛP R E ,即表1中NB 对应行向量,同理可以得到,712)0,,0,5.0,1,0(1⨯==ΛP R EC , 711)0,,0,5.0,1(0⨯==ΛP R U7721000000000005.05.00005.010)0,,0,5.0,1,0()0,,0,5.0,1(⨯⎥⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎢⎣⎡=⨯=⨯ΛM M M M M M ΛΛΛΛΛTEC E R R49121)0,,0,5.0,5.0,0,0,0,0,0,5.0,1,0(⨯=ΛEC E R7491211000000005.05.00005.0100000)0,,0,5.0,1()0,,5.0,1,0(⨯⎥⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎢⎣⎡=⨯=⨯=ΛM ΛM M M M ΛΛΛΛΛTU EC E R R Rif (E is NVB or NB) and (EC is NVB) then (U is PVB)1112U EC E R R R R ⨯⨯= 结果略按此法可得到27个关系子矩阵,对所有子矩阵取并集得到模糊关系矩阵如下:)27,,2,1(21ΛY ΛY Y ==i R R R R i由R 可以得到模拟量输出为:()U E EC R =⨯o4.去模糊化由上面得到的模拟量输出为1×7的模糊向量,每一行的行元素(u (z ij ))对应相应的离散变量z j ,则可通过加权平均法公式解模糊:)21,,2,1()()(210210Λ===∑∑==j i zu z zu u i iji jij从而得到实际刹车控制量的精确值u 。
油门控制:油门控制采用增量式PID 控制,即:)2()1()2()()()1()(-+---++++-=k e k k e k k k e k k k k u k u d d p d i p只需要设置p k 、 i k 、d k 三个参数即可输出油门控制量。
二、程序实现及参数调节 clear all%************************模糊算法 %/*********隶属度向量 *****% P0=[1,0.5,0,0,0,0,0];%*********NB P1=[0,1,0.5,0,0,0,0];%*********NM P2=[0,0.5,1,0.5,0,0,0];%*********NS P3=[0,0,0.5,1,0.5,0,0];%*********ZO P4=[0,0,0,0.5,1,0.5,0];%*********PS P5=[0,0,0,0,0.5,1,0];%*********PM P6=[0,0,0,0,0,0.5,1];%*********PB %***********语言值 *****%NB=-3;NM=-2;NS=-1;ZO=0;PS=1;PM=2;PB=3; %/*********模糊规则表*****% Pg=[PB PB PM PM PS ZO ZO; PB PM PM PS ZO ZO NS; PM PM PS PS ZO NS NS; PM PS PS ZO ZO NS NM; PS PS ZO ZO ZO NS NM; PS ZO ZO ZO NS NM NB; ZO ZO ZO NS NM NM NB];%/*********根据规则表计算模糊关系矩阵*****% R1_=dikaer(xbing(P0,P1),7,P0,7); R1_=reshape(R1_,1,49);R2_=dikaer(xbing(P2,P3),7,P0,7);R2_=reshape(R2_,1,49);R2=dikaer(R2_,49,P5,7);R3_=dikaer(P0,7,P1,7);R3_=reshape(R3_,1,49);R3=dikaer(R2_,49,P6,7);R4_=dikaer(xbing(P1,P2),7,P1,7);R4_=reshape(R4_,1,49);R4=dikaer(R4_,49,P5,7);R5_=dikaer(P3,7,P1,7);R5_=reshape(R5_,1,49);R5=dikaer(R5_,49,P4,7);R6_=dikaer(xbing(P0,P1),7,P2,7);R6_=reshape(R6_,1,49);R6=dikaer(R6_,49,P5,7);R7_=dikaer(xbing(P2,P3),7,P2,7);R7_=reshape(R7_,1,49);R7=dikaer(R7_,49,P4,7);R8_=dikaer(P0,7,P3,7);R8_=reshape(R8_,1,49);R8=dikaer(R8_,49,P5,7);R9_=dikaer(xbing(P1,P2),7,P3,7);R9_=reshape(R9_,1,49);R9=dikaer(R9_,49,P4,7);R10_=dikaer(P3,7,P3,7);R10_=reshape(R10_,1,49);R10=dikaer(R10_,49,P3,7);R11_=dikaer(xbing(P0,P1),7,P4,7); R11_=reshape(R11_,1,49);R11=dikaer(R11_,49,P4,7);P45=xbing(P4,P5);R12_=dikaer(xbing(P2,P3),7,P45,7); R12_=reshape(R12_,1,49);R12=dikaer(R12_,49,P3,7);R13_=dikaer(P0,7,P5,7);R13_=reshape(R13_,1,49);R13=dikaer(R13_,49,P4,7);R14_=dikaer(P1,7,P5,7);R14_=reshape(R14_,1,49);R14=dikaer(R14_,49,P3,7);P01=xbing(P0,P1);R15_=dikaer(xbing(P01,P2),7,P6,7); R15_=reshape(R15_,1,49);R16_=dikaer(P3,7,P6,7);R16_=reshape(R16_,1,49);R16=dikaer(R16_,49,P2,7);R17_=dikaer(P4,7,P0,7);R17_=reshape(R17_,1,49);R17=dikaer(R17_,49,P4,7);R18_=dikaer(xbing(P5,P6),7,P0,7);R18_=reshape(R18_,1,49);R18=dikaer(R18_,49,P3,7);R19_=dikaer(xbing(P4,P5),7,P1,7);R19_=reshape(R19_,1,49);R19=dikaer(R19_,49,P3,7);R20_=dikaer(P6,7,xbing(P1,P2),7);R20_=reshape(R20_,1,49);R20=dikaer(R20_,49,P2,7);P23=xbing(P2,P3);R21_=dikaer(P4,7,xbing(P23,P4),7);R21_=reshape(R21_,1,49);R21=dikaer(R21_,49,P3,7);R22_=dikaer(P5,7,xbing(P23,P4),7);R22_=reshape(R22_,1,49);R22=dikaer(R22_,49,P2,7);R23_=dikaer(P6,7,xbing(P3,P4),7);R23_=reshape(R23_,1,49);R23=dikaer(R23_,49,P1,7);R24_=dikaer(P4,7,P5,7);R24_=reshape(R24_,1,49);R24=dikaer(R24_,49,P2,7);R25_=dikaer(P5,7,P5,7);R25_=reshape(R25_,1,49);R25=dikaer(R25_,49,P1,7);R26_=dikaer(P6,7,xbing(P6,P5),7);R26_=reshape(R26_,1,49);R26=dikaer(R26_,49,P0,7);R27_=dikaer(xbing(P4,P5),7,P6,7);R27_=reshape(R27_,1,49);R27=dikaer(R27_,49,P1,7);m=[R1,R2,R3,R4,R5,R6,R7,R8,R9,R10,R11,R12,R13,R14,R15,R16,R17,R18,R19,R20,R21,R22,R 23,R24,R25,R26,R27];R=bingji(m);%*************初始化参量e=0;ec=0;y_1=0;y_2=0;u=0;u_1=0;u_2=0;u_3=0;e_1=0;e_2=0;Eswith=10;throttle_1=0;brake_1=0;x=[0 0 0];ts=0.001;sys=tf(1,[1,2,1],'inputdelay',0.5);dsys=c2d(sys,ts,'zoh');[num,den]=tfdata(dsys,'v');for k=1:1:40000%****************控制系统time(k)=k*ts;if(k<25000)vd(k)=40;elsevd(k)=0;endy(k)=-den(2)*y_1-den(3)*y_2+num(2)*u_1+num(3)*u_2; e=vd(k)-y(k);ec=e-e_1;u_3=u_2;u_2=u_1;u_1=u;y_2=y_1;y_1=y(k);x(1)=e;x(2)=(e-e_1)/ts;x(3)=x(3)+e*ts;%*******************************油门PID控制kp=0.42;Ti=30;Td=0.0018;ki=kp*ts/Ti;kd=kp*Td/ts;dthrottle=kp*x(1)+kd*x(2)+ki*x(3);throttle=u_1+dthrottle;if(throttle>2000)throttle=2000;end%****************************刹车控制%/********压缩输入变量*****%E=lisan(-50,50,3,e);EC=lisan(-20,20,3,ec);%/*********计算实际输入变量隶属度向量*****%E_R(1)=lbell(E,1,4,-3);E_R(2)=trig(E,-3,-2,0);E_R(3)=trig(E,-3,-1,1);E_R(4)=trig(E,-2,0,2);E_R(5)=trig(E,-1,1,3);E_R(6)=trig(E,0,2,3);E_R(7)=rbell(E,1,4,3);EC_R(1)=lbell(EC,1,4,-3);EC_R(2)=trig(EC,-3,-2,0);EC_R(3)=trig(EC,-3,-1,1);EC_R(4)=trig(EC,-2,0,2);EC_R(5)=trig(EC,-1,1,3);EC_R(6)=trig(EC,0,2,3);EC_R(7)=rbell(EC,1,4,3);%/*********模糊推理过程*****%U_R1=dikaer(E_R,7,EC_R,7);U_R1=reshape(U_R1,1,49);U_R2=jdikaer(U_R1,49,R,7);U_R=max(U_R2);u_L=mean(U_R);%/*********去模糊化*****%brake=-flisan(-150,150,3,u_L);e_2=e_1;e_1=e;%/************************选择规则if (e<0)if ((e>-Eswith)||(throttle_1~=0)) if(throttle<=throttle_1)throttle_1=throttle;u=throttle;Q(k)=u;W(k)=0;elsethrottle=0;throttle_1=throttle;u=throttle;Q(k)=u;W(k)=0;endelseif(throttle_1==0)brake_1=brake;u=brake;W(k)=u;Q(k)=0;elsethrottle=0;throttle_1=throttle;u=throttle;Q(k)=u;W(k)=0;endendelseif(e~=0)if(brake_1==0)throttle_1=throttle;u=throttle;Q(k)=u;W(k)=0;elsebrake=0;brake_1=brake;u=brake;endelseu=0;W(k)=0;Q(k)=0;endend%********************»-ͼÊä³öÁ¿¶¨ÒåM(k)=u;%******************************迟滞环节if (time(k)<=0.5)u=0;elseu=M(k-0.5/ts);endend%**********画图figure(1);plot(time,vd,'r',time,y,'k','linewidth',2); xlabel('time(s)');ylabel('vd,y');legend('ÆÚÍû','ʵ¼Ê');figure(2);plot(time,Q,'r','linewidth',2);xlabel('time(s)');ylabel('u');figure(3);plot(time,W,'r','linewidth',2);xlabel('time(s)');ylabel('u');figure(4);plot(time,N,'b');xlabel('time£¨s£©');ylabel('e');程序说明:仿真分加速和加速两个阶段,加速阶段主要应用油门控制,加速阶段主要由刹车控制。