www.gusucode.com > control 案例程序 matlab源码代码 > control/QueryModelCharacteristicsExample.m
%% Query Model Characteristics % This example shows how to query model characteristics such as stability, % time domain, and number of inputs and outputs. You can use the techniques of % this example on any type of dynamic system model. %% % Load a saved state-space (<docid:control_ref.f4-390421>) model. load(fullfile(matlabroot,'examples','control','queryexample.mat'),'T') %% % Query whether |T| has stable dynamics. Bstab = isstable(T) %% % The |isstable| command returns 1 (|true|) if all system poles are in the % open left-half plane (for continuous-time models) or inside the open unit % disk (for discrete-time models). Otherwise, |isstable| command returns 0 % (|false|). Here, the result shows that the model is stable. %% % Query whether |T| has time delays. Bdel = hasdelay(T) %% % The returned value, 1, indicates that |T| has a time delay. For a % state-space model, time delay can be stored as input delay, output delay, % internal delay, or a combination. Use |get(T)| to determine which % properties of |T| hold the time delay, and use dot notation to access the % delay values. The |hasInternalDelay| command tells you whether there is % any internal delay. %% % Query whether |T| is proper. Bprop = isproper(T) %% % The returned value indicates that the system has relative degree less % than or equal to 0. This is true of a SISO system when it can be % represented as a transfer function in which the degree of the numerator % does not exceed the degree of the denominator. %% % Query the order of |T|. N = order(T) %% % For a state-space model, |order| returns the number of states, which is 5 % in this case. For a |tf| or |zpk| model, the order is the number of % states required for a state-space realization of the system. %% % Query whether |T| is a discrete-time system. Bdisc = isdt(T) %% % The returned value indicates that |T| is % a discrete-time model. Similarly, use |isct| to query whether |T| is % a continuous-time model. %% % Load a MIMO model and query the input/output dimensions. load(fullfile(matlabroot,'examples','control','queryexample.mat'),'Tmimo') ios = iosize(Tmimo) %% % In the resulting array, the number of outputs is first. Therefore, % |Tmimo| has 4 inputs and 7 outputs.