$route[rawurlencode("статьи")] = "article/index";

$config['permitted_uri_chars'] = '?A-Za-zА-Яа-я=s&0-9~%.:&_-|@';

class MY_Router extends CI_Router {

    function _parse_routes() {
        $uri = implode('/', $this->uri->segments);

        if (isset($this->routes[$uri])) {
            return $this->_set_request(explode('/', $this->routes[$uri]));
        }

        foreach ($this->routes as $key => $val) {
            $key = rawurlencode(str_replace(':any', '.+', str_replace(':num', '[0-9]+', $key)));

            if (preg_match('#^' . $key . '$#', $uri)) {
                // Do we have a back-reference?
                if (strpos($val, '$') !== FALSE AND strpos($key, '(') !== FALSE) {
                    $val = preg_replace('#^' . $key . '$#', $val, $uri);
                }

                return $this->_set_request(explode('/', $val));
            }
        }
        $this->_set_request($this->uri->segments);
    }

}

class MY_URI extends CI_URI
{
    function _filter_uri($str)
    {
        if ($str != '' AND $this->config->item('permitted_uri_chars') != '')
        {
            if ( ! preg_match("|^[".preg_quote($this->config->item('permitted_uri_chars'))."]+$|i", rawurlencode($str)))
            {
                exit('The URI you submitted has disallowed characters.');
            }
        }

        return $str;
    }
}

setlocale(LC_ALL, 'ru_RU.UTF8');