Ship sailing with smooth steering, symbolizing friction reduction.

Smooth Sailing Ahead: How to Eliminate Steering Gear Friction and Boost Boat Performance

Beau Callahan in Tech & Innovation December 2025 • 4 min read.

"Discover innovative compensation methods for nonlinear friction in DDVC flange-type rotary vane steering gear, ensuring precise and stable vessel control."

For anyone navigating the waters, whether a seasoned sailor or a weekend boater, maintaining precise control over their vessel is paramount. Modern ships rely on advanced steering systems to ensure they can execute maneuvers accurately and maintain stability in varying conditions. One component that’s critical to a vessel’s steering performance is the steering gear, particularly the direct drive volume control flange-type rotary vane steering gear (DDVC-FRVSG).

The DDVC-FRVSG stands out due to its compact structure, effective vibration absorption, and straightforward control, making it a preferred choice for many vessels. However, even with its advanced design, the DDVC-FRVSG faces a significant challenge: nonlinear friction. This friction can compromise the steering gear's ability to meet the accuracy demands of modern vessels, leading to control inaccuracies and reduced stability.

Recent research introduces innovative compensation methods designed to tackle the issue of nonlinear friction in DDVC-FRVSG systems. By understanding the source of this friction and applying advanced control strategies, vessels can achieve smoother, more reliable steering performance.

Understanding Nonlinear Friction: The Enemy of Smooth Steering

Ship sailing with smooth steering, symbolizing friction reduction.

Before diving into the solutions, it's crucial to understand where this pesky friction comes from. In a DDVC-FRVSG system, nonlinearity mainly arises from two factors:

The external load moments applied on the rudder, which include hydrodynamic moment, friction torque, and inertia moment. Friction torque, in particular, stands out as a key nonlinear factor affecting the servo system's dynamic performance.

Clearance and Dry Friction: Minute gaps and dry surfaces within the servo system amplify nonlinearity, leading to operational inefficiencies.
Impact: This nonlinearity can cause frequency response issues, self-excited vibration, and a general decline in the rudder system's efficiency and control quality. It prevents the rudder from rapidly starting and accurately tracking its designated position, undermining the vessel’s maneuverability and course stability.
Friction Points: In DDVC-FRVSG systems, friction commonly occurs in the rudder bearing, between the rudder shaft and body. This friction diminishes the system's dynamic performance and introduces deviations like limit cycles, dead zones, and flat-topped curves.

Researchers have been studying this problem and developing models to better understand and compensate for friction in steering systems. One popular model is the LuGre model, known for its comprehensive description of static and dynamic friction performance. Armed with models like these, scientists are designing methods to counteract friction and improve steering precision.

The Future of Vessel Control: Enhanced Precision and Stability

The research and advancements in friction compensation for DDVC-FRVSG systems highlight an exciting future for vessel control. By continuing to refine these compensation methods, we can expect to see even greater improvements in steering precision, stability, and overall vessel performance. These advancements promise smoother, more efficient navigation for all types of watercraft, ensuring safer and more reliable journeys.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1371/journal.pone.0207018, Alternate LINK

Title: The Compensation For Nonlinear Friction Of Ddvc Flange-Type Rotary Vane Steering Gear

Subject: Multidisciplinary

Journal: PLOS ONE

Publisher: Public Library of Science (PLoS)

Authors: Lihua Liang, Luyang Wang, Jingfu Wang

Published: 2018-11-12

Everything You Need To Know

What is the main challenge faced by DDVC flange-type rotary vane steering gear (DDVC-FRVSG), and what are its consequences?

The primary challenge for the DDVC-FRVSG is nonlinear friction. This friction, arising mainly from external load moments and friction torque, leads to control inaccuracies and reduced stability. Specifically, it causes the rudder to struggle with rapid starts and accurate position tracking. The consequences include frequency response issues, self-excited vibration, a decline in rudder system efficiency, and diminished maneuverability and course stability.

What are the main sources of nonlinear friction in a DDVC-FRVSG system?

Nonlinear friction in a DDVC-FRVSG system primarily stems from two sources: the external load moments applied on the rudder, encompassing hydrodynamic moment, friction torque, and inertia moment, and clearance and dry friction within the servo system. The friction torque is a key nonlinear factor affecting the servo system's dynamic performance. Additional friction occurs in the rudder bearing, between the rudder shaft and body.

How do clearance, dry friction, and friction points impact the performance of the DDVC-FRVSG?

Clearance and dry friction in the servo system amplify nonlinearity, leading to operational inefficiencies. Friction points, like those in the rudder bearing, further diminish the system's dynamic performance. These factors introduce deviations such as limit cycles, dead zones, and flat-topped curves. They collectively undermine the rudder's ability to respond quickly and accurately, compromising the vessel's maneuverability and course stability.

What compensation methods are being developed to address nonlinear friction in DDVC-FRVSG systems?

Researchers are developing innovative compensation methods to counteract nonlinear friction in DDVC-FRVSG systems. These methods are designed to understand the source of this friction and apply advanced control strategies. Models like the LuGre model are used to comprehensively describe static and dynamic friction performance, which assists in designing these compensation methods.

Why is the DDVC-FRVSG chosen for many vessels, and what are the expected future advancements?

The DDVC-FRVSG is favored due to its compact structure, effective vibration absorption, and straightforward control. Future advancements involve refining compensation methods to improve steering precision, stability, and overall vessel performance. These improvements promise smoother, more efficient navigation and safer journeys for all watercraft. By continuing research in friction compensation, further enhancements in vessel control are anticipated.