Load abnormality detection apparatus performing accurate judgment of cause of abnormality

A load abnormality detection apparatus that detects a load abnormality in at least one of a first rotational member and a second rotational member provided in an apparatus including:

• the first rotational member and the second rotational member that act on each other;
• a first motor that drives said first rotational member and is controlled based on a first control element;
• and a second motor that drives said second rotational member and is controlled based on a second control element, said load abnormality detection apparatus comprising:
• an element acquisition part configured to acquire said first control element and said second control element;
• an inclination calculation part configured to calculate an inclination of change in said second control element;
• a first comparison part configured to compare said first control element with a first threshold value and also compare said first control element with a second threshold value larger than said first threshold value;
• a second comparison part configured to determine whether the inclination of change in said second control element is a positive value or zero or a negative value, and compare an absolute value of the inclination of change in said second control element with a seventh threshold value, which is a positive value;
• and an abnormality detection part configured to detect a load abnormality in a load applied to at least one of said first rotational member and said second rotational member based on results of comparison by said first comparison part and said second comparison part and identify a cause of the detected load abnormality.