robot body

Design and Technical Analysis of Underwater Dredging Robot Body

1. Introduction

Underwater dredging robot is an intelligent equipment specifically designed for cleaning silt and sediment at the bottom of water bodies. It is widely used in fields such as port and waterway maintenance, reservoir dredging, river management, and marine engineering. As the core part of the underwater operation system, the design of the robot body is directly related to the efficiency, safety, and reliability of dredging operations. This article will explore in detail the key technical elements such as the structural composition, material selection, power system, and control system of the underwater dredging robot body.

2、 Robot body structure design

1. Main framework structure

The body of underwater dredging robots usually adopts a modular design concept, and the main frame is composed of high-strength alloy materials, with the following characteristics:

(1) Pressure resistant structure: Adopting a cylindrical or rectangular sealed cabin design, it can withstand the huge water pressure caused by underwater working depth. For deepwater operation robots, the cabin usually adopts a segmented pressure resistant structure, with flange connections between each section to ensure overall strength and sealing.

(2) Anti corrosion treatment: The surface of the main frame is coated with a special anti-corrosion coating, such as epoxy resin coating or polyurethane coating, to prevent seawater corrosion. The key connection parts are made of stainless steel or titanium alloy materials.

(3) Modular layout: Place the power system, control system, operating system, etc. in separate compartments for easy maintenance and upgrading. The various functional modules are connected through quick plug interfaces, which improves the maintainability of the system.

2. Buoyancy and counterweight system

Underwater dredging robots require precise buoyancy control systems to maintain operational stability:

(1) Variable buoyancy system: By adjusting the water volume of the ballast tank or using expandable materials to change the buoyancy state of the robot, it can achieve upward, downward, and hovering.

(2) Static buoyancy material: fill the main frame with lightweight and high-strength buoyancy materials, such as synthetic foam or hollow glass bead composites, to provide basic buoyancy.

(3) Weight adjustment: The bottom can be equipped with adjustable weight blocks to balance the robot's posture during operation, especially to prevent tipping during dredging operations.

3、 Power propulsion system

1. Propulsion configuration

Underwater dredging robots typically adopt a multi thruster layout, with common configurations including:

(1) Main thrusters: 2-4 horizontally arranged propeller thrusters that provide forward, backward, and turning power. Powered by a brushless DC motor and equipped with a diffuser to improve propulsion efficiency.

(2) Vertical thrusters: 1-2 vertically arranged thrusters used to control the depth and pitch attitude of the robot. In complex water flow environments, vertical thrusters can help robots maintain stability.

(3) Vector propulsion system: High end dredging robots may use rotatable thrusters to achieve omnidirectional movement and precise positioning.

2. Power source selection

According to the work environment and task requirements, the power sources of underwater dredging robots mainly include the following:

(1) Cable power supply: Obtaining power from surface workboats through umbilical cables, suitable for long-term continuous operation scenarios. Cables simultaneously undertake the functions of power transmission and data transmission.

(2) Battery power supply: using high-energy density lithium batteries or fuel cells, suitable for short-term operations or scenarios that require high mobility. Usually needs to be used in conjunction with an automatic charging dock.

(3) Hybrid power system: Combining the advantages of cable power supply and battery power supply, cable power supply is used during the main operation phase, and switched to battery power supply during maneuvering or emergency situations.

4、 Dredging operation system

1. Design of dredging mechanism

The core operating system of underwater dredging robots usually includes:

(1) Suction system: consisting of a high-pressure water pump, a Venturi tube, and a filtering device, it sucks sludge into the conveying pipeline through negative pressure. The system design needs to consider factors such as particle size, concentration, and transportation distance.

(2) Mechanical disturbance device: devices such as rotating brushes, high-pressure water guns, or robotic arms used to loosen compacted sediment and improve dredging efficiency. Disturbance devices are usually installed at the front or bottom of robots.

(3) Transport system: Transport the inhaled sludge through pipelines to surface treatment equipment or designated discharge locations. Long distance transportation requires an intermediate pressurization device.

2. Homework tool interface

Modern underwater dredging robots often use standardized tool interfaces, which can quickly replace different operating tools:

(1) Hydraulic quick change interface: used to connect different types of dredging heads or robotic arms to achieve multifunctional operations.

(2) Electric tool interface: provides power and control signals for electric dredging tools.

(3) Auxiliary homework system: sensor interfaces such as cameras, sonars, etc., used for monitoring the homework process and quality assessment.

5、 Control system and sensors

1. Core control system

The control system of the underwater dredging robot adopts a layered architecture:

(1) Main controller: usually based on industrial grade embedded systems, running real-time operating systems, responsible for motion control, job coordination, and emergency response.

(2) Distributed subsystem: Each functional module (propulsion, dredging, navigation, etc.) is equipped with an independent microcontroller, which communicates with the main controller through CAN bus or Ethernet.

(3) Fault tolerant design: The critical control system adopts redundant design, and the main and backup controllers can seamlessly switch to ensure job safety.

2. Sensor system

The underwater dredging robot is equipped with multiple sensors to achieve environmental perception and status monitoring:

(1) Navigation and positioning sensors: By combining DVL (Doppler velocimeter), IMU (Inertial Measurement Unit), depth gauge, ultra short baseline positioning system, etc., precise underwater positioning can be achieved.

(2) Environmental perception sensors: Forward looking sonar, side scanning sonar, cameras, etc., used to identify terrain and obstacles in the work area.

(3) Homework monitoring sensors: flow meters, concentration meters, pressure sensors, etc., real-time monitoring of dredging operation parameters to optimize work efficiency.

(4) Status monitoring sensors: temperature, humidity, voltage and current sensors, etc., monitor the operating status of various systems of the robot.

6、 Sealing and protection design

Underwater dredging robots work in harsh environments, and sealing protection is crucial:

(1) Dynamic sealing technology: Moving parts such as propeller shafts and robotic arm joints adopt a multi-stage sealing structure, such as the combination of mechanical seals and magnetic fluid seals.

(2) Static sealing design: The cabin joint surface is sealed with O-ring, combined with sealant and pressure testing to ensure water tightness.

(3) Protective coating: External electronic devices and sensitive components are coated with anti biological adhesion to prevent marine organisms from adhering and affecting performance.

(4) Anti silt design: Key moving parts are equipped with protective covers and flushing systems to prevent silt from entering and causing malfunctions.