表单验证run() =总是false

我有这样的代码:

$update['recipe_name'] = $this->input->post('recipename');
    $update['recipe_description'] = $this->input->post('recipedescription');
    $update['recipe_instruction'] = $this->input->post('recipeinstruction');
    $this->form_validation->set_rules($update['recipe_name'], 'Name of '.$update['recipe_name'], 'trim|required');
    $this->form_validation->set_rules($update['recipe_description'], 'Description of '.$update['recipe_name'], 'trim|required');
    $this->form_validation->set_rules($update['recipe_instruction'], 'Instruction of '.$update['recipe_instruction'], 'trim|required');
    for($count=0;$count<$update['total_ingredients'];$count++)
    {
    $ingredient_inputs['id'] = $this->input->post('id'.$count);
    $ingredient_inputs['name'] = $this->input->post('ingredient'.$count);
    $ingredient_inputs['quantity'] = $this->input->post('quantity'.$count);
    $ingredient_inputs['measurement'] = $this->input->post('measurement'.$count);
    $this->form_validation->set_rules($ingredient_inputs['name'],'Name of '.$ingredient_inputs['name'], 'trim|required');
    $this->form_validation->set_rules($ingredient_inputs['quantity'], 'Quantity of '.$ingredient_inputs['name'], 'trim|required|numeric');
    $this->form_validation->set_rules($ingredient_inputs['measurement'], 'Measurement of '.$ingredient_inputs['name'], 'trim|required');
    $update['ingredients'][$ingredient_inputs['id']] = array('componentname'=>$ingredient_inputs['name'],
    'quantity'=>$ingredient_inputs['quantity'],'unit'=>$ingredient_inputs['measurement']);
    }
    if ($this->form_validation->run() == FALSE)
    {
    }

我不知道我的代码出了什么问题，或者set_rules的循环把它搞砸了。它没有显示任何错误，当我运行验证时，它总是false。