Codeigniter未定义属性，可以'；t将模型加载到控制器中

我正在使用CodeIgniter 3，我在这个网站上看到过类似的问题，并尝试了提供的每一种解决方案，但都无济于事。

我正在尝试使用CodeIgniter通过cli创建一个表。但这导致了一个我似乎无法理解的错误，任何帮助都将不胜感激！

型号：

<?php
class App_model extends CI_Model {
  public function __construct(){
    parent::__construct();
    $this->load->database();
  }
  public function create_table(){
    $this->drop();
    $sql='CREATE TABLE app (
      id int(11) NOT NULL AUTO_INCREMENT,
      text text NOT NULL,
      PRIMARY KEY (id)
    );';
    $this->db->query($sql);
  }
  public function drop(){
    $this->db->query('DROP TABLE app');
  }
}
?>

控制器：

<?php
defined('BASEPATH') OR exit('No direct script access allowed');
class App extends CI_Controller {
    public function __contruct(){
      parent::__construct();
      $this->load->model('App_model');
    }
    public function test(){
      $this->App_model->create_table();
    }
}
?>

终端：

asergey91:~/workspace $ php index.php App test
A PHP Error was encountered
Severity:    Notice
Message:     Undefined property: App::$App_model
Filename:    /home/ubuntu/workspace/application/controllers/App.php
Line Number: 10
Backtrace:
        File: /home/ubuntu/workspace/application/controllers/App.php
        Line: 10
        Function: _error_handler
        File: /home/ubuntu/workspace/index.php
        Line: 292
        Function: require_once

Fatal error: Call to a member function create_table() on a non-object in /home/ubuntu/workspace/application/controllers/App.php on line 10
Call Stack:
    0.0003     255192   1. {main}() /home/ubuntu/workspace/index.php:0
    0.0010     317824   2. require_once('/home/ubuntu/workspace/system/core/CodeIgniter.php') /home/ubuntu/workspace/index.php:292
    0.0171    1549776   3. call_user_func_array:{/home/ubuntu/workspace/system/core/CodeIgniter.php:514}() /home/ubuntu/workspace/system/core/CodeIgniter.php:514
    0.0171    1550040   4. App->test() /home/ubuntu/workspace/system/core/CodeIgniter.php:514

A PHP Error was encountered
Severity:    Error
Message:     Call to a member function create_table() on a non-object
Filename:    /home/ubuntu/workspace/application/controllers/App.php
Line Number: 10
Backtrace: