level.m

来自「Matlab学习课件」· M 代码 · 共 127 行

function level
% Level control task

procglbl	% Global definitions

global slevel_next
	% These aren't really global,  but do have to be 'static'
	% Matlab doesn't have a 'static' declaration so this will have to do!

if Slevel == 0
	% Initialization section - occurs once only
	Slevel = 1;	% Make sure this section is not executed again!
	slevel_next = 1;	% First state.
		%The default is -1 which indicates stay in same state
	return;
end

% This task could be run either as timed or continuous. As a timed task it
% saves some computing time if it needn't run all the time
if tstep < Tlevel_next
	return;
end

Tlevel_next = Tlevel_next + Tlevel;	% Time for next run

if slevel_next ~= -1
	% There has been a state change (including self-transition)
	 [i_audit,trans_trail]=audit(3,Slevel,slevel_next,tstep,trans_trail,i_audit);	% Record this transition
	Slevel = slevel_next;
	run_entry = 1;
	slevel_next = -1;	% Default - stay in same state
else
	run_entry = 0;
end

if Slevel == 1	% Monitor
	% Figure out which tank needs service
	% Needing service is determined by the tank with the lowest level
	% Service is needed if the lowest level is less than (high + low)/2

	% No entry section
	% No action section
	% Test/exit section
	imin = 1; hmin = h1;
	if h2 < hmin, imin = 2; hmin = h2; end
	if h3 < hmin, imin = 3; hmin = h3; end
	if hmin < (hhigh + hlow) / 2
		% A tank needs filling
		if imin == 1, slevel_next = 2;	% to Move1
		elseif imin == 2, slevel_next = 4;	% to Move2
		elseif imin == 3, slevel_next = 6;	% to Move3
		end
	end
elseif Slevel == 2	% Move1
	if run_entry
		Xnext_car = xt1;	% Set new carriage position for tank1
	end
	% No action section
	% Test/exit section
	if abs(Xset_car - xt1) < 0.1
		% OK to start puming
		slevel_next = 3;
	end
elseif Slevel == 3	% Pump1 
	if run_entry
		flow_a = pa1set * flowmax;
		flow_b = (1 - pa1set) * flowmax;
	end
	% No action section
	% Test/exit section
	% In this implementation it is easier to eliminate the Wait_Pump
	% state and include that test here
	if h1 >= hhigh
		flow_a = 0;	% Turn pumps off
		flow_b = 0;
		slevel_next = 1;		% to Monitor
	end
elseif Slevel == 4	% Move2
	if run_entry
		Xnext_car = xt2;	% Set new carriage position for tank2
	end
	% No action section
	% Test/exit section
	if abs(Xset_car - xt2) < 0.1
		% OK to start puming
		slevel_next = 5;
	end
elseif Slevel == 5	% Pump2 
	if run_entry
		flow_a = pa2set * flowmax;
		flow_b = (1 - pa2set) * flowmax;
	end
	% No action section
	% Test/exit section
	% In this implementation it is easier to eliminate the Wait_Pump
	% state and include that test here
	if h2 >= hhigh
		flow_a = 0;	% Turn pumps off
		flow_b = 0;
		slevel_next = 1;		% to Monitor
	end
elseif Slevel == 6	% Move3
	if run_entry
		Xnext_car = xt3;	% Set new carriage position for tank3
	end
	% No action section
	% Test/exit section
	if abs(Xset_car - xt3) < 0.1
		% OK to start puming
		slevel_next = 7;
	end
elseif Slevel == 7	% Pump3
	if run_entry
		flow_a = pa3set * flowmax;
		flow_b = (1 - pa3set) * flowmax;
	end
	% No action section
	% Test/exit section
	% In this implementation it is easier to eliminate the Wait_Pump
	% state and include that test here
	if h3 >= hhigh
		flow_a = 0;	% Turn pumps off
		flow_b = 0;
		slevel_next = 1;		% to Monitor
	end
end