Trim angle control apparatus and trim angle control method

A trim angle control apparatus configured to control a trim angle of an outboard motor including a prime mover, comprising:

• a detector configured to detect a rotational speed of the prime mover;
• an actuator configured to adjust the trim angle of the outboard motor;
• an operation member configured to be operated by a ship operator to input a change command for changing the trim angle;
• and
• an electronic control unit including a processor and a memory coupled to the processor, wherein
• the memory stores a target value of the trim angle for each rotational speed range of the prime mover, wherein
• the processor is configured to perform:
• controlling the actuator so that the trim angle becomes the target value, wherein
• the target value includes:
• a first target value for each rotational speed range set in advance to be larger in a higher rotational speed range;
• and
• a second target value for each rotational speed range set in accordance with operation by the ship operator, wherein
• the change command includes:
• a trim up command for increasing the trim angle;
• and
• a trim down command for decreasing the trim angle, wherein the processor:
• sets the first target value corresponding to a current rotational speed range including the rotational speed detected by the detector;
• sets a change amount of the trim angle in accordance with the change command when the change command is input through the operation member;
• sets the second target value corresponding to the current rotational speed range by adding the change amount to the first target value corresponding to the current rotational speed range;
• determines whether the second target value corresponding to the current rotational speed range exceeds the first target value corresponding to a rotational speed range immediately higher than the current rotational speed range when the trim up command is input;
• sets the second target value corresponding to the rotational speed range immediately higher than the current rotational speed range to the same value as the second target value corresponding to the current rotational speed range when it is determined that the second target value corresponding to the current rotational speed range exceeds the first target value corresponding to the rotational speed range immediately higher than the current rotational speed range;
• and
• controls the actuator so that the trim angle becomes the second target value.