www.pudn.com > truetime-1.2-compiled.zip > servo_init.m

function servo_init

% PID-control of a DC servo process.
%
% This example shows four ways to implement a periodic controller
% activity in TrueTime. The task implements a standard
% PID-controller to control a DC-servo process (2nd order system). 

% Initialize TrueTime kernel
ttInitKernel(2, 1, 'prioFP'); % nbrOfInputs, nbrOfOutputs, fixed priority

% Task attributes
period = 0.006;
deadline = period;
offset = 0.0; % start of first task job
prio = 1;

% Create task data (local memory)
data.K = 0.96;
data.Ti = 0.12;
data.Td = 0.049;
data.N = 10;
data.h = period;
data.u = 0;
data.Iold = 0;
data.Dold = 0;
data.yold = 0;
data.rChan = 1;
data.yChan = 2;
data.uChan = 1;

% IMPLEMENTATION 1a: using the built-in support for periodic tasks
% 
ttCreatePeriodicTask('pid_task', offset, period, prio, 'pidcode1', data);

% IMPLEMENTATION 1b: calling Simulink block within code function
%
% data2.u = 0; % Only the control signal needs to be stored between
               % segments. Controller states are stored internally by
               % TrueTime.
% ttCreatePeriodicTask('pid_task', offset, period, prio, 'blockcode', data2);

% IMPLEMENTATION 2: sleepUntil and loop back
%
% data.t = 0;
% ttCreateTask('pid_task', deadline, prio, 'pidcode2', data);
% ttCreateJob('pid_task');

% IMPLEMENTATION 3: sampling in timer handler, triggers task job
%
% hdl_data.yChan = 2;
% ttCreateInterruptHandler('timer_handler', prio, 'samplercode', hdl_data);
% ttCreatePeriodicTimer('timer', offset, period, 'timer_handler');
%
% ttCreateMailbox('Samples', 10);
%
% ttCreateTask('pid_task', deadline, prio, 'pidcode3', data);