znalazłem jedną funkcję i dodałem kilka elementów swoich powinno działać

<?php
function transcribe($string,$r=0) {
$string1 = strtr($string,array("Ą" => "A", "ą" => "a",
"ć" => "c", "Ć" => "C", "Ę" => "E", "ę" => "e",
"ł" => "l", "Ł" => "L", "Ń" => "N", "ń" => "n",
"ó" => "o", "Ó" => "O", "ś" => "s", "Ś" => "S",
"ż" => "z", "Ż" => "Z", "Ź" => "Z", "ź" => "z", "," => "", "!" => "","@"=>"",
"#"=>"","$"=>"","%"=>"","^"=>"","&"=>"","*"=>"","("=>"",
")"=>"","-"=>".","_"=>".","+"=>".","="=>".",";"=>"",":"=>"","""=>"",
"}"=>"","{"=>"","["=>"","]"=>"",""=>"","|"=>"","'"=>"","~"=>"",
"`"=>"","<"=>"",">"=>"","?"=>"","/"=>""));
$string = strtr($string1,
"xA1xAAxBAxBFxC0xC1xC2xC3xC5xC7
xC8xC9xCAxCBxCCxCDxCExCFxD0xD1
xD2xD3xD4xD5xD8xD9xDAxDBxDDxE0
xE1xE2xE3xE5xE7xE8xE9xEAxEBxEC
xEDxEExEFxF0xF1xF2xF3xF4xF5xF8
xF9xFAxFBxFDxFF",
"!ao?AAAAAC
EEEEIIIIDN
OOOOOUUUYa
aaaaceeeei
iiidnooooo
uuuyy");
$string2 = strtr($string, array("xC4"=>"Ae", "xC6"=>"AE", "xD6"=>"Oe", "xDC"=>"Ue", "xDE"=>"TH", "xDF"=>"ss", "xE4"=>"ae", "xE6"=>"ae", "xF6"=>"oe", "xFC"=>"ue", "xFE"=>"th"));
if($r){$string2=strtolower($string2);}
return($string2);
}
?>
działa z niemieckimi francuskimi i polskimi z resztą nie wiem bo nie sprawdzałem dodałem też usunięcie znaków specjalnych (w moim przypadku było to konieczne ale można sobie wyrzucić

do tego jakbyco kilka znaków specjalnych do wyrzucenia z tekstu
<?php
"xe1xc1xe0xc0xe2xc2xe4xc4xe3xc3xe5xc5".
"xaaxe7xc7xe9xc9xe8xc8xeaxcaxebxcbxed".
"xcdxecxccxeexcexefxcfxf1xd1xf3xd3xf2".
"xd2xf4xd4xf6xd6xf5xd5x8xd8xbaxf0xfa".
"xdaxf9xd9xfbxdbxfcxdcxfdxddxffxe6xc6xdf",
"aAaAaAaAaAaAacCeEeEeEeEiIiIiIiInNoOoOoOoOoOoOoouUuUuUuUyYyaAs"));
$txt2=strtr($txt,array("?"=>"","*"=>"","$"=>"","_"=>".",","=>".","("=>"",")"=>"",'%'=>"","&"=>"",""=>"","'"=>"","/"=>"", "€"=>"",'"'=>"","i»ż"=>"","™"=>"","`"=>"",""=>"","«"=>"","-"=>".","ˇ"=>"","”"=>"","!"=>"","˛"=>"","ź"=>"","ć"=>"","+"=>"","="=>"","^"=>"",
"‚"=>"","†"=>"","’"=>"",":"=>"",";"=>"","©"=>"","•"=>"","¤"=>"","đ"=>"","„"=>"","›"=>"",""=>"","ť"=>"","®"=>"","‡"=>"","š"=>"",
"¨"=>"",""=>"","ł"=>"","ľ"=>"","¸"=>"","~"=>"","‹"=>"","»"=>"","¦"=>"","˝"=>"","¶"=>"","ź"=>"z","ą"=>"a","°"=>"","§"=>"","¬"=>"",
"ś"=>"s","n"=>""," "=>"","—"=>"","‘"=>"","
"=>"","÷"=>"","ř"=>"r","ž"=>"","ż"=>"z","ę"=>"e","ţ"=>"","|"=>"","´"=>"","˘"=>"","µ"=>"u","–"=>"","“"=>"","…"=>"","‰"=>"",
"±"=>"","·"=>"","<"=>"",">"=>"","["=>".","]"=>".","{"=>".","}"=>".","í"=>"","à"=>"a","é"=>"e"
));
?>