Добавить изображение с помощью ajax в codeigniter - не сохранять данные

Мне нужна ваша помощь в следующем коде, и я потратил на поиск решений, и ни одно из них не полезно, когда я пытаюсь сохранить, ничего не сохраняет в базе данных, не могли бы вы мне помочь.

Это мой ВЗГЛЯД

    <div class = "modal fade" id = "add_modal_para" tabindex = "-1" role = "dialog" aria-labelledby = "title" aria-hidden = "true">
  <div class = "modal-dialog" role = "document">
    <div class = "modal-content">
      <div class = "modal-header">
        <h5 class = "modal-title" id = "title" style = "font-weight: 700;">Agregar</h5>
        <button type = "button" class = "close" data-dismiss = "modal" aria-label = "Close">
          <span aria-hidden = "true">&times;</span>
        </button>
      </div>

      <div class = "modal-body">
      <form method = "post" id = "form_add_para" enctype = "multipart/form-data">
        <div class = "input-group mb-3">
            <div class = "input-group-prepend">
                <span class = "input-group-text" id = "basic-addon1"><i class = "fas fa-poop"></i></span>
            </div>
                <input type = "text" name = "txt_firtsname_para" id = "txt_firtsname_para" class = "form-control" placeholder = "Nombres" maxlength = "50" aria-label = "Nombres" aria-describedby = "basic-addon1" data-validation-error-msg-container = "#txt_firtsname-error-dialog" data-validation = "required custom length" data-validation-regexp = "^[a-zA-Z\s]+$" data-validation-length = "min3" data-validation-length = "max50">
        </div>
                <div id = "txt_firtsname-error-dialog"></div>

        <div class = "input-group mb-3">
            <div class = "input-group-prepend">
                <label for = "txt_avatar">Imagen</label>
            </div>
                <input type = "file" class = "form-control-file" id = "txt_avatar_para" name = "txt_avatar_para">
        </div>

      </div>
          <div class = "modal-footer">
            <button type = "submit" id = "btn_add_para" class = "btn btn-success"><i class = "fas fa-save"></i> Guardar</button>
            <button type = "button" class = "btn btn-secondary" data-dismiss = "modal"><i class = "fas fa-sign-in-alt"></i> Cerrar</button>
          </div>
      </form>

    </div>
  </div>
</div>

Это мой код AJAX

$('#submit').submit(function(e){
            e.preventDefault(); 
                 $.ajax({
                     url: baseurl+'app/Paramilitar/add_Para',
                     type: "POST",
                     data: new FormData(this),
                     dataType: "JSON",
                     processData:false, 
                     contentType:false,
                     cache:false,
                     async:false,
                     success: function(data){
                        $("#form_add_para")[0].reset();
                        $('#add_modal_para').modal('hide');
                        show_para_table();
                   }
                 });
            });

Это мой КОНТРОЛЛЕР

public function add_Para(){ 
    $config['upload_path']='./assets/uploads/';
        $config['allowed_types']='jpeg|jpg|png';
        $config['encrypt_name'] = TRUE;

        $this->load->library('upload', $config);

        if ($this->upload->do_upload('txt_avatar_para'))
        {
        $data_ima = array('upload_data' => $this->upload->data());

        $data_person = array(
        'id_person_type' => '3',
        'firtsname' => $this->input->post('txt_firtsname_para'),
        'avatar' => $data_ima['upload_data']['file_name'],
        'active' => '1'
        );  

        $data_result= $this->Person_model->Insert_Person($data_person);
        echo json_encode($data_result); 
        }     

Это моя МОДЕЛЬ Пример модели:
публичная функция Insert_Person ($ data_person) { $ data_result = $ this-> db-> insert ('tbl_person', $ data_person); вернуть $ data_result; }