An autopilot controls the steering gear of a vessel to keep it on course. There are two types of control methods. One is called single-loop control and uses torque motors or the like, and the other is called two-loop control which uses solenoid valves or servo-cylinders as actuators. The actuator selection depends on what type of steering gear is used.

PT500: This type is widely applicable to many types of vessels and can be easily adapted to any type of steering gears and actuators.

PT70: This type is suitable to middle size and small vessels which use solenoid valves. It is designed for easy mounting on the consoles of small vessels.

The autopilot system is configured with the following basic components.
1) Control Stand
Control stand consists of the following units, which are also adequate to the panel-mount.
- Auto unit
- Annunciator unit
- Hand steering unit
- Switch units
2) Control Power Supply Box
3) "μ"Transmitters
4) Actuators (Supplied and handled by the steering gear manufacturer)

Autopilot system

- NAVI mode (FU Steering)
This mode enables track control. Interface with INS equipment such as ECDIS is required.

- AUTO mode (FU Steering)
This mode automatically keeps the ship's heading to a preset course. A heading reference signal from a gyrocompass is required.

- HAND mode (FU Steering)
This mode manually controls ship's heading from the steering wheel on the front of control stand. Number of potentiometers mechanized in the steering wheel can be provided in coincidence with the number of steering control chains.

- RC mode (FU Steering)
This mode manually controls the ship's heading, and the control can be done away from the control stand. A dial remote controller or the like is required.

- NFU steering
This mode directly drives the actuators of the steering gear. The rudder is driven when the lever switch is moved to port or starboard, and stops moving when the lever switch is in neutral.

Autopilot system

PB343 Auto-steering Unit (Adaptive auto unit)
PB344 Auto-steering Unit (PID auto unit)
These units are used in AUTO mode. The AUTO mode contains following controls:
- Adaptive control (PB343), and
- PID control (PB344).
Each of the above models are customized to suite each vessel's specifications.

PB345 Auto-steering Unit (PID auto unit : Optional)
This unit is the same as PB344 but is designed for longitudinal mounting.

PB335 Hand-steering Unit
This unit uses hand steering in HAND mode. Steering angle and direction indicators are positioned alongside the wheel.

PT161 Dial Steering Unit (Optional)
The unit is remote controller used in RC mode.

MKR051 Steering Repeater Compass
This unit is a ship's heading repeater for use by the helmsman, and dimming control is available. This unit is suitable for panel-mounting or wall-mounting.

PH614 Annunciator Unit
This unit displays the operating status of the autopilot and issues visible and audible alarms when a failure occurs. Repertoire of display is provided by accordance with the specification requirements of the autopilot.

PH718 Switch Unit (SYSTEM switch)
This unit consists of two switches arranged on a single panel. The first switch selects follow up control chains (FU1 or FU2) or non-follow-up (NFU) control chains to be used, and the second switch is on the non-follow-up (NFU) lever. The NFU lever is functional when NFU control is selected.

RH720 Switch Unit (MODE switch)
This unit is the steering mode selector. This unit is provided in accordance with the specifications of the autopilot.

PH721 Switch Unit
The unit is used when two auto-steering units are employed. There are two types of switches as follows depending on the system.
- ADAP/PID switch
- PID1/PID2 switch

Autopilot system