System Design

Explicit Design Requirements

Maximum size of 16" (width) x 16" (depth) x 30" (height) which will allow it to move around the testbed.
Maximum cost of $1000.
Robust design to withstand many uses and any mishaps.
Remain stable on up to 10° sloped due to ship rocking in extreme marine weather.
Able to traverse various types of ship surfaces, including steel and aluminum decking.
Maximum speed of 10 feet per second.
Capable of manipulating the wheels valves, spigot valves and switches in its environment.
Able to rotate the valves ±90° in any orientation.
Able to rotate valves to a specific location withing ±15°.
Capable of large force outputs to push the switches to on/off position.
Battery run-time of at least 10 minutes.
Low maintenence required to extend the lifetime of the robot.

Implicit Design Requirements

The shipbot should be able to read and understand the instructions in the mission file.
It must be able to sense its environment and localize itself.
Must verify the completeness of a task.
Less than one minutes per task.

Coolness Factors

It must have proper communication with the existing control systems on the ship.
Dual camera setup - one fixed on the arm to provide a panoramic view of the surrounding environment, and another mounted on the end effector for visual servoing purposes.
Compact design for small storage and easy integration into the ship.
5 degree of freedom arm grants the ability to manipulate valves in random locations.

Endoscope camera view

Robot travelling under the pipe

Functional Architecture

The robot upon starting aligns itself with the first segment and checks if there is a task at current segment, if not it moves to the next segment and if yes it begins to center itself and identifies the task from the mission file and identifies the workspace. It then proceeds to find whether the task needs to be updated or not - if the answer is no it moves to the next segment and if yes, it locks itself in the position and proceeds to perform the task by taking the data from the cameras to localize itself and position the end effector. It further checks that the actions were performed successfully if not it repeats the cycle once again until successful and checks if this was the last task if yes it exits the path and comes to rest. If this was not the last task it moves on to the next segment which then repeats the performing cycle.

Cyber-Physical Architecture

The cyber physical architecture is divided into several subsystems which will be dependent on each other. These include sensing subsystem, manipulator subsystem and locomotion subsystem.

Sensing subsystem: The sensing subsystem will be vision for the robot. The system is composed of two main vision sensors, one for scanning the environment and one for scanning the manipulator position. We will use OpenCV with our controller for software integration.

Locomotion Subsystem: We will be using 4 mecanum wheels controlled via 50 RPM geared motors with encoder feedback. All the motors will be controlled centrally via motor microcontroller.

Manipulator Subsystem: we will design a manipulator algorithm to control HEBI X-5 and X-8 motors that will give the manipulator 5 DOFs which include Table HEBI, Base HEBI, Elbow HEBI, Wrist 1 HEBI, and Wrist 2 HEBI.

System Description

The robot's system is a highly advanced and reliable solution designed to help manage various controls on ships. This system consists of a mobile base equipped with a 4 DOF manipulator and computer vision capabilities, as well as a battery management system, and a control system that integrates with the Raspberry Pi.

The Mobile Base

The mobile base of the ship control management system plays a crucial role in ensuring that the robot can complete its tasks efficiently and effectively. The base is designed to move in any direction, including diagonals, providing the flexibility needed to navigate the complex environment of a ship. The mecanum wheel design is well-suited for this type of application, as it allows for superior mobility and stability even on uneven surfaces.

To ensure precise control, the mobile base is equipped with geared motors with encoders. The encoders track the base's movement accurately, allowing the system to reach its target location with precision. This precise control is essential for tasks such as turning knobs or flipping switches, which require a high degree of accuracy to complete successfully.

The base is constructed from a combination of acrylic material and aluminum channels, which provides a balance of strength, durability and lightweight. The lightweight construction makes it easy to maintain and repair, ensuring that the system can continue to operate without fail. Additionally, the aluminum channels reinforce the acrylic base, providing the necessary structural strength to withstand the demands of the ship environment.

Mobile Base

Mobile Base With Electronics and Arm Mechanism

The Manipulator

The manipulator of the ship control management system is a key component responsible for completing various tasks such as turning knobs or flipping switches. It is a 5 degree-of-freedom (DOF) system, meaning it has five independent axes of motion, which provides the flexibility needed to complete a wide range of tasks.

The manipulator is constructed using HEBI modules, which are modular, high-performance actuators that are known for their durability, precision, and ease of use. The manipulator has two links, with one motor serving as the base, one as the elbow, and two at the wrist. This design allows for smooth and precise movements, ensuring that the robot can accurately reach its target and complete its tasks.

The end effector of the manipulator is a simple and effective solution for manipulating the environment. It consists of two prongs mounted on a circular base, which provide a secure grip on objects. The design of the manipulator is inspired from the kind of operations the effector is expected to perform over the course of the mission plan.

5 Degree of Freedom Manipulator

Arm Link Stresses and Displacements

The Control System

The control system of the ship control management system is a crucial aspect that enables the robot to perform its tasks. It makes use of a Jetson Nano, a small and low-power single-board computer, as the central processing unit to control the robot’s motion and perform high-level tasks such as obstacle avoidance and path planning. The Jetson Nano communicates with the manipulator and the mobile base to ensure coordinated and smooth movements.

In addition to the Jetson Nano, the control system also incorporates a Realtek depth camera for sensing. The camera provides the robot with the necessary information to understand its environment and complete its tasks effectively. This combination of the Jetson Nano and the depth camera provides the control system with the necessary processing power and sensory input to ensure that the robot can perform its tasks with high accuracy.

The control system also incorporates a battery management system, which is responsible for ensuring that the robot has sufficient power to complete its tasks. The battery management system monitors the robot’s power consumption and ensures that the battery level is maintained at an optimal level to avoid any power-related issues during operation. This helps to ensure that the robot can operate continuously without any interruptions and helps to extend the lifespan of the battery.

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