Cargo handling control device of forklift truck

A cargo handling control device of a forklift truck, the forklift truck including a lift cylinder configured to raise and lower a fork holding a pallet and a tilt cylinder configured to tilt the fork, the cargo handling control device comprising:

• a first detector configured to detect whether a distal portion of the fork inserted into a pallet hole of the pallet is adjacent to an upper wall of the pallet, the first detector being configured to output a detection signal;
• a second detector configured to detect whether the distal portion of the fork inserted into the pallet hole of the pallet is adjacent to a lower wall of the pallet, the second detector being configured to output a detection signal;
• a third detector configured to detect whether a proximal portion of the fork inserted into the pallet hole of the pallet is in contact with the upper wall of the pallet, the third detector being configured to output a detection signal;
• a fork lowering controller configured to control the lift cylinder so that the lift cylinder lowers the fork holding the pallet toward a loading surface;
• a pallet posture determination unit configured to determine a posture of the pallet relative to the fork based on the detection signals from the first detector, the second detector, and the third detector, after the fork lowering controller starts controlling the lift cylinder;
• a pallet placement controller configured to control the lift cylinder and the tilt cylinder so that the fork is placed on the loading surface depending on the posture of the pallet relative to the fork determined by the pallet posture determination unit;
• and
• a fork withdrawal controller configured to control the forklift truck so that the forklift truck pulls the fork out of the pallet after the pallet placement controller completes controlling the lift cylinder and the tilt cylinder, wherein
• the pallet placement controller judges based on the posture of the pallet whether the fork is allowed to be pulled out of the pallet,
• when the pallet placement controller judges that the fork is allowed to be pulled out of the pallet, the pallet placement controller controls the lift cylinder so that the lift cylinder stops lowering the fork, and
• when the pallet placement controller judges that the fork is not allowed to be pulled out of the pallet, the pallet placement controller controls the tilt cylinder so that tilt cylinder tilts the fork along the loading surface.