a sensor interface that acquires a photographed image from a sensor that photographs an image of a cargo group;

a gripping unit interface that communicates with a gripping unit configured to grip a piece of cargo of the cargo group; and

a processor that:

recognizes, from the photographed image, each piece of cargo of a same-type cargo group including a same type of cargo,

transmits, in a case of successfully recognizing each piece of cargo of the same-type cargo group, a first control signal to the gripping unit through the gripping unit interface to perform unloading according to a first gripping method corresponding to the same-type cargo group, and

transmits, in a case of failing to recognize each piece of cargo of the same-type cargo group, a second control signal to the gripping unit through the gripping unit interface to perform unloading according to a second gripping method corresponding to a mixed-type cargo group including different types of cargo;

wherein, in a case of failing to recognize each piece of cargo of the same-type cargo group, the processor extracts from the photographed image a cargo group region in which a piece of cargo of an upper tier is captured, determines a gripping position based on the cargo group region, and transmits the second control signal to the gripping unit based on the gripping position;

wherein, in a case of successfully recognizing each piece of cargo of the same-type cargo group, as the first gripping method, the processor extracts a cargo region of each piece of cargo from the photographed image, formulates a gripping plan based on the cargo region, and transmits the first control signal to the gripping unit based on the gripping plan;

wherein, as the second gripping method, the processor extracts a candidate edge facing the gripping unit in a direction from the gripping unit to the cargo from an outer frame of the cargo group region, and determines the gripping position on the candidate edge;

wherein the first gripping method is a method of gripping a plurality of pieces of cargo; and

wherein the second gripping method is a method of gripping one piece of cargo.