In the process of ship navigation, the steering gear, as the core component of the control system, plays a vital role. The steering gear changes the course of the ship by controlling the deflection angle of the rudder blade, so as to realize the accurate control of the ship’s movement. The angle positioning of the steering gear is directly related to the maneuverability and navigation safety of the ship. Therefore, scientific and reasonable positioning of steering gear angle is an important link that can not be ignored in ship design and maintenance.
First, the basic concept of steering gear angle
The rudder angle refers to the angle at which the rudder blade deviates from the centerline (zero position) of the ship, usually expressed in degrees. The range of rudder angle is generally between 35, of which 35 is considered as the maximum effective rudder angle. The rudder angle determines the turning moment of the rudder and the turning performance of the ship. Excessive rudder angle may lead to instability of rudder force, but reduce steering efficiency; If it is too small, it can’t meet the demand of rapid steering.
Second, the importance of steering gear angle positioning
The accurate control of steering gear angle is of great significance to the safe navigation of ships. On the one hand, the deviation of rudder angle will lead to the instability of ship’s course, increase the frequency of course correction and affect navigation efficiency; On the other hand, if there is an error in the steering angle feedback system, it may lead to overload or even damage of the steering gear, which may lead to safety accidents in serious cases. In addition, the precise control of the rudder angle is even more indispensable in complex operations such as ships leaving the dock and sailing in narrow channels.
Third, the way to realize the angle positioning of steering gear
1. Mechanical positioning method
Early ships used mechanical methods to locate the rudder angle, such as calibrating the rudder angle position by dial or pointer. This method is intuitive and simple, but its accuracy is low, and it is easy to cause errors due to mechanical wear.
2. Potentiometer feedback positioning
Potentiometers are widely used in modern
steering gear for angle feedback. The potentiometer is installed on the tiller shaft, which outputs the corresponding voltage signal with the change of rudder angle and feeds it back to the bridge through the control system to realize closed-loop control. This method has the advantages of fast response and high precision, and is commonly used in small and medium-sized ships at present.
3. Photoelectric encoder positioning
The photoelectric encoder is often used to detect the rudder angle of large ships with high precision requirements. Photoelectric encoder can provide higher resolution and stability, reflect the accurate value of rudder angle in real time, and is suitable for ship control system with high degree of automation.
4. Remote monitoring and
automatic calibration
With the improvement of ship automation level, modern steering gear systems are usually equipped with remote monitoring devices, and steering angle information can be transmitted to the bridge or centralized control room through the bus. At the same time, the system has the function of automatic calibration, which regularly detects and corrects the angle deviation to ensure the accuracy of steering angle positioning.
Four, steering gear angle calibration matters needing attention
In order to ensure the accuracy of steering gear angle, the following work should be carried out regularly in daily maintenance:
-Check whether the feedback devices (such as potentiometers and encoders) are loose or worn;
-Check the consistency between mechanical zero position and electrical zero position;
-Compare the error
between the displayed angle of the bridge and the actual rudder angle;
-Re-calibrate and debug if necessary.
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To sum up, the accurate positioning of steering gear angle is an important basis to ensure the safe and efficient navigation of ships. With the development of ship automation and intelligence, the technology of rudder angle detection and control is also improving. Ship management and operators should strengthen the understanding and maintenance of the steering gear system, ensure that the steering gear is always in good working condition, and escort the ship safety.