How to Obtain Custom Taxonomy ID and Convert to Int?

I’m having trouble obtaining the id of my custom taxonomy term, then converting it into a int to be used in wp_set_object_terms().

Here’s the code I’m using:

function default_cat($post_ID)
{
    $terms = get_the_terms( $post->ID , 'control' );
    if($terms) {
	foreach( $terms as $term ) {
        $cat_ids = array($term->term_id);
        $cat_ids = array_map('intval', $cat_ids );
        }
}

    wp_set_object_terms( $post_ID, $cat_ids, 'category' );
}
add_action('publish_post', 'default_cat');

I keep getting an error about the second argument in array_map() not being an array. What am I doing wrong?