DC-3 Steering Gear

DC-III (DC-III S) Series Automatic Steering Systems

I. Product Overview

The DC-III series autopilot is a new-generation autopilot featuring remarkable characteristics such as high stability, full digitalization, comprehensive functionality, and excellent scalability. The computing module employs a high-performance computer and an embedded operating system, and the control algorithm is a fuzzy PID self-tuning algorithm. Under various weather conditions and load scenarios, this autopilot delivers outstanding control performance for ships of different types. It is equipped with two completely independent control systems.
The system offers steering modes including automatic, follow-up, manual (emergency), and dynamic positioning. It can also be optionally equipped with remote control stations on both sides and auxiliary steering stations suitable for steering from the ship’s stern, depending on actual operational needs. The system is capable of controlling both single-propeller and twin-propeller vessels.

II. Main Features

The DC—III series autopilot is designed for vessels equipped with dual steering gear systems and can provide asynchronous following or emergency steering control as required by the operator. It features two completely independent control systems, each with its own set of electrical and control signals. Both systems can simultaneously control two steering gears, and they serve as hot backups for each other, enabling seamless real-time switching—or automatic switching if desired. Should the currently active controller fail, the system will automatically switch over to the backup system in real time without any manual intervention, thereby significantly enhancing safety. The autopilot employs a fuzzy PID algorithm that boasts excellent adaptability, insensitivity to changes in ship handling characteristics, rapid convergence, and strong anti-interference performance. Data processing is handled by a PC104 motherboard equipped with a 500 MHz CPU, which offers substantially higher computing speed and capability compared to other processors, ensuring more timely control responses and making it possible to implement even more complex algorithms. Thanks to the use of a 12.1-inch color LED display, the autopilot provides richer and more intuitive displays of navigation status, simplifying human-machine interaction and improving operability. The product adopts a modular design, facilitating easy installation for users. With an extensive array of hardware and software interfaces, the autopilot exhibits strong scalability, allowing customization of its functions to meet specific user requirements.

DC-ⅢS is suitable for single-actuator vessels.

III. Main Technical Specifications
Applicable operating temperature: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 0 — +55℃
Power supply:
Servo motor—main power supply—380V ~50Hz 250W
Servo control of main power— — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — 220V ~50Hz 80W
Servo-controlled emergency power supply ———— 24VDC 100W (standby)
Heading Display — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — 0–360°, with a resolution of 0.1°
Electro-magnetic compass heading indication error ≤ 0.5°
Magnetic compass heading indication error ≤ 1°
Automatic steering:
Instruction heading indicator — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — 0–360° with a resolution of 1°
Instruction error — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — ≤0.5°
Follow-up steering:
Steering follow-up sensitivity ———————————————————————————— ≤1°
Tracking error ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ≤1° (no greater than 0.5° when the rudder angle is positive)
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Rudder Angle Indicator ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ————......Rudder Angle Indicator ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ————...... ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ————............ ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ———— ————......
Rudder angle indication error ———————————————————————————— ≤1°
Output control object: Solenoid valve for the switch hydraulic steering system (24VDC 2A)

4. Instrument Accessories

(1) DC—III Automatic Steering System

(2) DC—IIIS Automatic Steering System

V. System Connection Diagram

VI. Examples of Major Components and Assemblies