An Inverse Kinematics Algorithm With Smooth Task Switching for Redundant Robots

This letter presents an inverse kinematics approach that combines two well-known Jacobian based methods, the task-priority framework and an optimization-based approach, such that tracking and optimization tasks can be executed simultaneously. The novelty of the proposed algorithm lies in the ability to smoothly switch between different tasks...

Filtered Split-Path Nonlinear Integrator: A Hybrid Controller for Transient Performance Improvement

The filtered split-path nonlinear integrator (F-SPANI) is a generic nonlinear controller designed to improve the transient performance of linear (motion) systems in terms of overshoot. The main idea underlying F-SPANI is that the amplitude and phase of an integrator can be tuned using independent filters, resulting in more efficient use of...

Automatic Docking for Underactuated Ships Based on Multi-Objective Nonlinear Model Predictive Control

Autonomous shipping refers to the ability of a ship to independently control its own actions while transporting cargo from one port to another, which places higher requirements on ship motion control methods. When a ship enters a port, it is important to ensure that the ship sails from the fairway area to the assigned position at the berth...

Offshore Loading and Discharge in Heavy Marine Transport

Dry transporting large heavy floating structures has been an important development in the innovative history of Heavy Marine Transport. This is done by carrying these type of cargoes on the deck of Heavy Transport Vessels. Loading and discharge is preformed by submerging the transport vessel, and positioning the cargo above the deck using tugger...

State-of-the-Art Research on Motion Control of Maritime Autonomous Surface Ships

At present, with the development of waterborne transport vehicles, research on ship faces a new round of challenges in terms of intelligence and autonomy. The concept of maritime autonomous surface ships (MASS) has been put forward by the International Maritime Organization in 2017, in which MASS become the new focus of the waterborne...

Long-Stroke Hydraulic Robot Motion Control With Incremental Nonlinear Dynamic Inversion

High precision motion control of hydraulic manipulators is challenging due to the highly nonlinear dynamics and model uncertainties typical for hydraulic actuators. This paper addresses the implementation of a novel sensor-based incremental nonlinear dynamic inversion control technique for a high-precision hydraulic force controller in existence...

Automated Multi-core Scheduling for an Industrial-sized Mechatronic Motion Control Platform

Mechatronic embedded control systems are becoming increasingly sophisticated and computationally demanding. These systems typically consists of multiple controllers, which coordinate the actuators and apply feedback based on data collected by sensors. Often the underlying control strategy is entirely described in a software application, which...

A Guiding Vector-Field algorithm for path-following control of nonholonomic mobile robots

In this paper, we propose an algorithm for path-following control of the nonholonomic mobile robot based on the idea of the guiding vector field (GVF). The desired path may be an arbitrary smooth curve in its implicit form, that is, a level set of a predefined smooth function. Using this function and the robot's kinematic model, we design a...

Mixture of Attractors: A novel movement primitive representation for learning motor skills from demonstrations

In this letter, we introduce Mixture of Attractors, a novel movement primitive representation that allows for learning complex object-relative movements. The movement primitive representation inherently supports multiple coordinate frames, enabling the system to generalize a skill to unseen object positions and orientations. In contrast to...

Heave reduction of the crane tip of a J-class vessel by inducing a roll moment using active ballast systems

To compensate the heaving motion of a payload during deep water offshore installations, hanging from an on-board crane on a monohull vessel, a new concept is being investigated. By actively rolling the vessel using ballasting systems, the coupled heave motion of the crane tip can be reduced significantly. This is investigated by building a...

Guiding vector field algorithm for a moving path following problem

This paper presents a guidance algorithm solving the problem of moving path following, that is, steering a mobile robot to a curvilinear path attached to a moving frame. The nonholonomic robot is described by the unicycle-type model under the influence of some constant exogenous disturbance. The desired path may be an arbitrary smooth curve...

Steering Micro-Robotic Swarm by Dynamic Actuating Fields

We present a general solution for steering microrobotic<br/>swarm by dynamic actuating fields. In our approach, the<br/>motion of micro-robots is controlled by changing the actuating<br/>direction of a field applied to them. The time-series sequence<br/>of actuating field’s directions can be computed automatically.<br/>Given a target position in...

A highly versatile autonomous underwater vehicle with biomechanical propulsion

An autonomous underwater vehicle with a biomechanical propulsion system is a possible answer to the demand for small, silent sensor platforms in many fields. The design of Galatea, a bio-mimetic AUV, involves four aspects: hydrodynamic shape, the propulsion, the motion control systems and payload. The shape of the hull is based on a modified...

Adaptive Iterative Learning Control for High Precision Motion Systems

Iterative learning control (ILC) is a very effective technique to reduce systematic errors that occur in systems that repetitively perform the same motion or operation. However, several characteristics have prevented standard ILC from being widely used for high precision motion systems. Most importantly, the learned feedforward signal depends on...

Stability and Motion Control of Ocean Vehicles