Upload pictures and data create dynamically codeigniter - php

Question

I need to upload pictures and data create dynamically html and jQuery I use codeigneter framework and send the the all data to mysql.
This is code controller
public function Addtest() {
$this->load->library('upload');
$u= $this->session->userdata('id_user');
$files = $_FILES;
$cpt = count($_FILES['sliderimg']['name']);
$inputAll= $this->input->post();
$this->load->model('AddData');
for($i=0; $i < count($inputAll['artilce']); $i++) {
$_FILES['sliderimg']['name']= $files['sliderimg']['name'][$i];
$_FILES['sliderimg']['type']= $files['sliderimg']['type'][$i];
// $_FILES['sliderimg']['tmp_name']= $files['sliderimg']['tmp_name'][$i];
$this->upload->initialize($this->set_upload_options());
$this->upload->do_upload();
var_dump($_FILES);
$data= array(
'id_user'=>$u,
'description2'=>$inputAll['description2'][$i],
'description1'=>$inputAll['description1'][$i],
'art'=>$inputAll['artilce'][$i],
$_FILES['sliderimg']['name']= $files['sliderimg']['name'][$i],
$image_name =>$_FILES['sliderimg']['name'][$i],
);
if( $this->AddData->Add_data($data)) {
echo 'false';
} else {
echo 'true';
}
and this the model code
public function Add_data($artt) {
extract($artt);
$data = array(
'Art'=>$art,
'des1'=>$description1,
'desc2'=>$description2,
'picture'=>$image_name,
'id_foreign'=>$id_user,
);
$this->db->insert('table',$data);
}
and the this the error output while I try to upload 2 pictures and data
A PHP Error was encountered
Severity: Notice
Message: Undefined variable: image_name
and this is the set_upload_options() function
private function set_upload_options()
{
$config = array();
$config['upload_path'] = './uploads/';
$config['allowed_types'] = 'gif|jpg|png|jpeg';
$config['max_size'] = '2048000';
$config['max_width'] = '20000';
$config['max_height'] = '17680';
$config['overwrite'] = FALSE;
return $config;
}
and the do_uplaod:
public function do_upload() {
$config['upload_path'] = './uploads/';
$config['allowed_types'] = 'gif|jpg|png|jpeg';
$config['max_size'] = '2048000';
$config['max_width'] = '2024';
$config['max_height'] = '1068';
$this->load->library('upload', $config);
if ( ! $this->upload->do_upload())
{
return "false";
}
else
{
return "true";
}
}