整车cruise控制.rar_Cruise Control_cruise_traceujz_整车_整车控制

% cruise_response.m - cruise control response curves % RMM, 17 Sep 04 % % Required files: none aminit; % initialize paths %% %% Cruise controller %% %% This is a simple PI cruise controller using the vehicle dynamics that %% are part of the running example described in chapter 3. The vehicle %% dynamics are defined in the function 'cruisedyn', which needs to be %% in the path. %% % Parameter definitions m1 = 1000; % mass of the car, kg m2 = 2000; % mass of the car, kg m3 = 3000; % mass of the car, kg a = 2; % engine lag coefficient % Numerically compute the gain and time constant for the vehicle dynamics vehspd = 25; % nominal speed, m/s vehthr = 0.135; % throttle to hold speed vehgr = 3; % gear vehpole1 = (cruisedyn(vehspd+0.1, vehthr, 3, 0, m1) - ... cruisedyn(vehspd-0.1, vehthr, 3, 0, m1) ) / 0.2; vehgain1 = (cruisedyn(vehspd, vehthr+0.01, 3, 0, m1) - ... cruisedyn(vehspd, vehthr-0.01, 3, 0, m1) ) / 0.01; vehpole2 = (cruisedyn(vehspd+0.1, vehthr, 3, 0, m2) - ... cruisedyn(vehspd-0.1, vehthr, 3, 0, m2) ) / 0.2; vehgain2 = (cruisedyn(vehspd, vehthr+0.01, 3, 0, m2) - ... cruisedyn(vehspd, vehthr-0.01, 3, 0, m2) ) / 0.01; vehpole3 = (cruisedyn(vehspd+0.1, vehthr, 3, 0, m3) - ... cruisedyn(vehspd-0.1, vehthr, 3, 0, m3) ) / 0.2; vehgain3 = (cruisedyn(vehspd, vehthr+0.01, 3, 0, m3) - ... cruisedyn(vehspd, vehthr-0.01, 3, 0, m3) ) / 0.01; % Dynamics veh1 = tf([vehgain1], [1 -vehpole1]); % vehicle veh2 = tf([vehgain2], [1 -vehpole2]); % vehicle veh3 = tf([vehgain3], [1 -vehpole3]); % vehicle eng = tf(a, [1 a]); % engine dynamics % Controller Ki = 0.02; % integral gain Kp = 1; % proportional gain ctr = tf([Kp Ki], [1 0.01*Ki/Kp]); % control: PI w/ LF pole % Now compute the complete system model (loop transfer function) cruise1 = ctr*eng*veh1; cruise2 = ctr*eng*veh2; cruise3 = ctr*eng*veh3; % Plot step response for two different masses sys1 = feedback(cruise1, 1); [resp1,T] = step(sys1, 20); sys2 = feedback(cruise2, 1); [resp2,T] = step(sys2, T); sys3 = feedback(cruise3, 1); [resp3,T] = step(sys3, T); % Now rescale the plot so that we go from 25 to 30 m/s time = [0; 2.5 + T]; step1 = [25; 25 + 5*resp1]; step2 = [25; 25 + 5*resp2]; step3 = [25; 25 + 5*resp3]; % Plot the results clf; subplot(321); % Plot the main data lines h = plot(time, step1, 'b-', time, step2, 'b-', time, step3, 'b-'); set(h, 'LineWidth', AM_data_linewidth); % Plot the reference lines hold on; h = plot([0; 2.5; 2.5; max(time)], [25; 25; 30; 30], 'k-'); set(h, 'LineWidth', AM_ref_linewidth); % Label the axes axis([0 10 24 33]); xlabel('time (sec)'); ylabel('speed (m/s)'); % And reset all of the parameters so that it looks write for the book set(gca, 'DataAspectRatio', [1 2 1]); set(gca, 'YTick', [20, 25, 30, 35]); set(gca, 'XTick', [0:5:20]); % arcarrow([2.7, 29.8], [3.7, 28.5], 8); % legh = legend(gca, 'm = 1000 kg', 'm = 2000 kg', 'm = 3000 kg', ... % 'Location', [0.32, 0.685, 0.1, 0.05]); % legend(legh, 'boxoff'); % set(legh, 'FontSize', 8); amprint('cruise-response.eps');