How i can translate uppercase to lowercase letters in a rewrite rule in nginx web server?

Yes, you are going to need perl.

If you are using Ubuntu, instead of apt-get install nginx-full, use apt-get install nginx-extras, which will have the embedded perl module.

Then, in your configuration file:

  http {
  ...
    # Include the perl module
    perl_modules perl/lib;
    ...
    # Define this function
    perl_set $uri_lowercase 'sub {
      my $r = shift;
      my $uri = $r->uri;
      $uri = lc($uri);
      return $uri;
    }';
    ...
    server {
    ...
      # As your first location entry, tell nginx to rewrite your uri,
      # if the path contains uppercase characters
      location ~ [A-Z] {
        rewrite ^(.*)$ $scheme://$host$uri_lowercase;
      }
    ...