impact.m

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%%
 % Copyright (c) 2012, Silvio Vallorani <silvio.vallorani@studio.unibo.it>
 %
 % Permission  to  use,  copy,  modify,  and/or distribute this
 % software  for  any  purpose  with  or  without fee is hereby
 % granted,  provided  that the above copyright notice and this
 % permission notice appear in all copies.
 %
 % THE  SOFTWARE  IS  PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS
 % ALL  WARRANTIES  WITH  REGARD TO THIS SOFTWARE INCLUDING ALL
 % IMPLIED  WARRANTIES  OF  MERCHANTABILITY  AND FITNESS. IN NO
 % EVENT  SHALL  THE  AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
 % INDIRECT,   OR   CONSEQUENTIAL   DAMAGES   OR   ANY  DAMAGES
 % WHATSOEVER  RESULTING  FROM  LOSS  OF  USE, DATA OR PROFITS,
 % WHETHER  IN  AN  ACTION  OF  CONTRACT,  NEGLIGENCE  OR OTHER
 % TORTIOUS  ACTION,  ARISING  OUT OF OR IN CONNECTION WITH THE
 % USE OR PERFORMANCE OF THIS SOFTWARE.
 %
 %%
%%
% @file impact.m
%
% Here 256 samples for impactPatterns are generated accordingly to
% 
% Taku Hachisu et al. (2011)
% Pseudo-Haptic Feedback Augmented with Visual and Tactile Vibrations
% 
% Q(t) =  A(v) * e^(-B*t) * sin(2*pi*f*t)     (1)
% 
% where Amplitude is function of velocity but quasi-linearity implies
% we can semplify in
%
% Q(t) =  A * v * e^(-B*t) * sin(2*pi*f*t)
%
% Use this formula as Haptic Pattern Sample Generator needs some other
% manipulations:
%
% PS(t) = abs(A) * v * [ 2*e^(-B*t) * (1 + sin(2*pi*f*t) ]
%
% This approch ensures non negative samples mainteining continuity.
% Samples are also scaled to remain in (1/3) * PMN_LEVELS range (slow).
%
% @author Silvio Vallorani
% @version v0.1
% @date 2012
%
%%

close all; clear all; clc;

% Generic Parameters

PWM_LEVELS = 65000; % number of PWM levels that can be used in HapticLib

t = ( 0 : 0.00035 : 0.1 );  % ensure impact transitory estinguish
                            % in 256 samples

V1 = 1; V2 = 2; V3 = 3; % Three different impact velocity magnitude are 
                        % defined. 
                        % V1 => SLOW
                        % V2 => NORMALW
                        % V3 => FAST
                        %
                        % Samples must be generated using V1.
                        

%% ALUMINUM

A_Aluminum = - 300;              A_Aluminum = abs ( A_Aluminum );
B_Aluminum = 90;
F_Aluminum = 300;

S_Aluminum = 1 + sin( 2 * pi * F_Aluminum * t );
E_Aluminum = 2 * exp( - B_Aluminum * t );

H_Aluminum = A_Aluminum * S_Aluminum .* E_Aluminum;
SCALE_FACTOR = ceil( max( H_Aluminum ) );
H_Aluminum = floor ( H_Aluminum / SCALE_FACTOR * (PWM_LEVELS/3) );
H_Aluminum_V1 = V1 * H_Aluminum;
H_Aluminum_V2 = V2 * H_Aluminum;
H_Aluminum_V3 = V3 * H_Aluminum;

subplot( 3, 3, 7 );
plot( t, H_Aluminum_V1 ), title( 'ALUMINUM @ SLOW' ), axis( [0 t(256) 0 PWM_LEVELS ] )
subplot( 3, 3, 8 );
plot( t, H_Aluminum_V2 ), title( 'ALUMINUM @ NORMAL' ), axis( [0 t(256) 0 PWM_LEVELS ] )
subplot( 3, 3, 9 );
plot( t, H_Aluminum_V3 ), title( 'ALUMINUM @ FAST' ), axis( [0 t(256) 0 PWM_LEVELS ] )

%% RUBBER

A_Rubber = - 240;                 A_Rubber = abs ( A_Rubber );
B_Rubber = 60;
F_Rubber = 30;

S_Rubber = 1 + sin( 2 * pi * F_Rubber * t );
E_Rubber = 2 * exp( - B_Rubber * t);

H_Rubber = A_Rubber * S_Rubber .* E_Rubber;
H_Rubber = floor ( H_Rubber / SCALE_FACTOR * (PWM_LEVELS/3) );
H_Rubber_V1 = V1 * H_Rubber;
H_Rubber_V2 = V2 * H_Rubber;
H_Rubber_V3 = V3 * H_Rubber;

subplot( 3, 3, 1 );
plot( t, H_Rubber_V1 ), title( 'RUBBER @ SLOW' ), axis( [0 t(256) 0 PWM_LEVELS ] )
subplot( 3, 3, 2 );
plot( t, H_Rubber_V2 ), title( 'RUBBER @ NORMAL' ), axis( [0 t(256) 0 PWM_LEVELS ] )
subplot( 3, 3, 3 );
plot( t, H_Rubber_V3 ), title( 'RUBBER @ FAST' ), axis( [0 t(256) 0 PWM_LEVELS ] )

%% WOOD

A_Wood = - 150;                   A_Wood = abs ( A_Wood );
B_Wood = 80;
F_Wood = 100;

S_Wood = 1 + sin( 2 * pi * F_Wood * t );
E_Wood = 2 * exp( - B_Wood * t );

H_Wood = A_Wood * S_Wood .* E_Wood;
H_Wood = floor ( H_Wood / SCALE_FACTOR * (PWM_LEVELS/3) );
H_Wood_V1 = V1 * H_Wood;
H_Wood_V2 = V2 * H_Wood;
H_Wood_V3 = V3 * H_Wood;

subplot( 3, 3, 4 );
plot( t, H_Wood_V1 ), title( 'WOOD @ SLOW' ), axis( [0 t(256) 0 PWM_LEVELS ] )
subplot( 3, 3, 5 );
plot( t, H_Wood_V2 ), title( 'WOOD @ NORMAL' ), axis( [0 t(256) 0 PWM_LEVELS ] )
subplot( 3, 3, 6 );
plot( t, H_Wood_V3 ), title( 'WOOD @ FAST' ), axis( [0 t(256) 0 PWM_LEVELS ] )

% WRITE RESULTS ON TXT FILE

fileID = fopen('impact.txt', 'w', 'n');
formatPattern = '%5d,\t%5d,\t%5d,\t%5d,\t%5d,\t%5d,\t%5d,\t%5d,\t%5d,\t%5d,\t\t\\\n';

fprintf(fileID, 'const uint8_t rubberImpactPattern[256] = {\t\t\t\t\t\t\t\t\t\t\t\\\n');
fprintf(fileID, formatPattern, H_Rubber_V1(1:255));
fprintf(fileID, '%5d\t\t\t\t\t\t\t\t\t\t};\n\n',0);

fprintf(fileID, 'const uint8_t woodImpactPattern[256] = {\t\t\t\t\t\t\t\t\t\t\t\\\n');
fprintf(fileID, formatPattern, H_Wood_V1(1:255));
fprintf(fileID, '%5d\t\t\t\t\t\t\t\t\t\t};\n\n',0);

fprintf(fileID, 'const uint8_t aluminumImpactPattern[256] = {\t\t\t\t\t\t\t\t\t\t\\\n');
fprintf(fileID, formatPattern, H_Aluminum_V1(1:255));
fprintf(fileID, '%5d\t\t\t\t\t\t\t\t\t\t};\n\n',0);
fclose(fileID);

fprintf('\nText file with Samples generated.\n')

%% PRINT THE MAX
fprintf('\nBiggest Sample values exracted from FAST Patterns\n\n')
fprintf('Biggest Rubber Sample: %5d\n',max(H_Rubber_V3))
fprintf('Biggest Wood Sample: %5d\n',max(H_Wood_V3))
fprintf('Biggest Aluminum Sample: %5d\n',max(H_Aluminum_V3))
fprintf('\n\n')