Search results

1 – 10 of over 1000
To view the access options for this content please click here
Article
Publication date: 1 December 2003

Zhao Yang, Cao Xi‐Bin and Sun Zhao‐Wei

In this paper, dynamic behavior of docking mechanism during its acquisition period is analyzed. The results show that the docking mechanism can be modeled as a six‐freedom…

Abstract

In this paper, dynamic behavior of docking mechanism during its acquisition period is analyzed. The results show that the docking mechanism can be modeled as a six‐freedom rigid body with a flexible support during this period, i.e. a typical structure. Because there exists nonlinear characteristics due to spacing, retardation, and friction in transmission elements and elements themselves, the theoretical analysis shows that docking mechanism can be simplified as a linear system and its dynamic characteristics determined through testing‐spectral function recognition method based on the linear vibration theory and corresponding software, after weakening effects of nonlinear factors. In order to determine whether docking mechanism has basic characteristics of a linear structure, some experiments have been carried out. The results show that testing‐spectral function recognition method can be used in dynamic systems.

Details

Aircraft Engineering and Aerospace Technology, vol. 75 no. 6
Type: Research Article
ISSN: 0002-2667

Keywords

To view the access options for this content please click here
Article
Publication date: 23 January 2019

Huang Jianbin, Li Zhi, Huang Longfei, Meng Bo, Han Xu and Pang Yujia

According to the requirements of servicing and deorbiting the failure satellites, especially the tumbling ones on geosynchronous orbit, this paper aims to design a docking

Abstract

Purpose

According to the requirements of servicing and deorbiting the failure satellites, especially the tumbling ones on geosynchronous orbit, this paper aims to design a docking mechanism to capture these tumbling satellites in orbit, to analyze the dynamics of the docking system and to develop a new collision force-limited control method in various docking speeds.

Design/methodology/approach

The mechanism includes a cone-rod mechanism which captures the apogee engine with a full consideration of despinning and damping characteristics and a locking and releasing mechanism which rigidly connects the international standard interface ring (Marman rings, such as 937B, 1194 and 1194A mechanical interface). The docking mechanism was designed under-actuated, aimed to greatly reduce the difficulty of control and ensure the continuity, synchronization and force uniformity under the process of repeatedly capturing, despinning, locking and releasing the tumbling satellite. The dynamic model of docking mechanism was established, and the impact force was analyzed in the docking process. Furthermore, a collision detection and compliance control method is proposed by using the active force-limited Cartesian impedance control and passive damping mechanism design.

Findings

A variety of conditions were set for the docking kinematics and dynamics simulation. The simulation and low-speed docking experiment results showed that the force translation in the docking phase was stable, the mechanism design scheme was reasonable and feasible and the proposed force-limited Cartesian impedance control could detect the collision and keep the external force within the desired value.

Originality/value

The paper presents a universal docking mechanism and force-limited Cartesian impedance control approach to capture the tumbling non-cooperative satellite. The docking mechanism was designed under-actuated to greatly reduce the difficulty of control and ensure the continuity, synchronization and force uniformity. The dynamic model of docking mechanism was established. The impact force was controlled within desired value by using a combination of active force-limited control approach and passive damping mechanism.

To view the access options for this content please click here
Article
Publication date: 21 March 2016

Weidong Zhu, Along Zhang, Biao Mei and Yinglin Ke

A large number of fastener holes have to be drilled with high quality in the circumferential splice region during the assembly of aircraft fuselage. The purpose of this…

Abstract

Purpose

A large number of fastener holes have to be drilled with high quality in the circumferential splice region during the assembly of aircraft fuselage. The purpose of this paper is to design an automatic stepping mechanism for a circumferential splice drilling machine, to meet the requirements of large workspace and high accuracy in drilling at the same time.

Design/methodology/approach

A docking position detection method based on magnetic proximity sensors is proposed for the positioning of the arc-shaped rail with respect to the circumferential rails, which significantly improves the accuracy and reliability of automatic stepping. The slipping phenomenon of the end-effector is analyzed, and the optimized counter weights are used to eliminate the slipping and improve the working stability of the stepping mechanism.

Findings

An automatic stepping mechanism is developed for the circumferential splice drilling machine, which comprises the docking position detection method and the elimination/suppression method of the end-effector’s slipping.

Practical implications

The proposed automatic stepping mechanism has been integrated into the circumferential splice drilling machine for the fuselage assembly in an aircraft company in China.

Originality/value

An automatic stepping scheme for the circumferential splice drilling machine is proposed, which enhances the efficiency in circumferential splice drilling in aircraft fuselage assembly.

Details

Industrial Robot: An International Journal, vol. 43 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

To view the access options for this content please click here
Article
Publication date: 4 July 2016

Pierpaolo Pergola and Vittorio Cipolla

The purpose of this paper is to deal with the study of an innovative unmanned mission to Mars, which is aimed at acquiring a great amount of detailed data related to both…

Abstract

Purpose

The purpose of this paper is to deal with the study of an innovative unmanned mission to Mars, which is aimed at acquiring a great amount of detailed data related to both Mars’ atmosphere and surface.

Design/methodology/approach

The Mars surface exploration is conceived by means of a fleet of drones flying among a set of reference points (acting also as entry capsules and charging stations) on the surface. The three key enabling technologies of the proposed mission are the use of small satellites (used in constellation with a minimum of three), the use of electric propulsion systems for the interplanetary transfer (to reduce the propellant mass fraction) and lightweight, efficient, drones designed to operate in the harsh Mars environment and with its tiny atmosphere.

Findings

The low-thrust Earth-Mars transfer is designed by means of an optimization approach resulting in a duration of slightly more than 27 months with a propellant amount of about 125 kg, which is compatible with the choice of considering a 500 kg-class spacecraft. Four candidate drone configurations have been selected as the result of a sensitivity analysis. Flight endurance, weight and drone size have been considered as the driving design parameters for the selection of the final configuration, which is characterized by six rotors, a total mass of about 6.5 kg and a flight endurance of 28 minutes. In the mission scenario proposed, the drone is assumed to be delivered on the Mars surface by means of a passive entry capsule, which acts also as a docking station and charging base. Such a capsule has been sized both in terms of mass (68 kg) and power (80 W), showing to be compatible with 500 kg-class spacecraft.

Research limitations/implications

As a general conclusion, the study shows the mission concept feasibility.

Practical implications

The concept would return incomparable scientific data and can be also be potentially implemented with a relatively low budget exploiting of the shelf components to the larger extent, small identical spacecraft buses and modular low-cost drones.

Originality/value

The innovative mission architecture proposed in this study aims at providing a complete coverage of the surface and lowest atmospheric layers. The main innovation factor of the proposed mission consists in the adoption of small multi-copter UAVs, also called “drones,” as remote-sensing platforms.

Details

International Journal of Intelligent Unmanned Systems, vol. 4 no. 3
Type: Research Article
ISSN: 2049-6427

Keywords

To view the access options for this content please click here
Article
Publication date: 1 August 2005

Zhao Yang, Tian Hao and Cao Xi‐bin

To provide the basis and rule of theory analysis for the design of transmission parameters of the buffer system of the space docking mechanism.

Abstract

Purpose

To provide the basis and rule of theory analysis for the design of transmission parameters of the buffer system of the space docking mechanism.

Design/methodology/approach

Setting up the dynamic model of the buffer system of the space docking mechanism by adopting virtual work theory, and analyzing the effects of the transmission parameters of the buffer system to the system dynamic characteristics on the basis of the decouple principle.

Findings

The buffer characteristics of the docking mechanism varying with the change of the transmission parameters of the buffer system, and the change of the buffer force characteristics of the translation degree of freedom are more prominent than that of the turning angle degree of freedom; the mechanics characteristics of the buffer system will approximately satisfy the decouple requirement by selecting the appropriate transmission parameters.

Research limitations/implications

Only consider the transmission parameters for the transmission elements in the buffer system dynamic model, without considering the mass and inertia parameters.

Practical implications

Provides valuable method of parameter design to design the transmission system of the space docking mechanism.

Originality/value

Putting forward up the method of approximation to solve the sub‐ diagonalize matrix of the stiff matrix and the damp matrix, and then determining some main transmission ratio of the system. This method is simple, practical for the system design.

Details

Aircraft Engineering and Aerospace Technology, vol. 77 no. 4
Type: Research Article
ISSN: 0002-2667

Keywords

To view the access options for this content please click here
Article
Publication date: 16 May 2016

Changhong Gao, Dacheng Cong, Xiaochu Liu, Zhidong Yang and Han Tao

The purpose of this paper is to propose a hybrid position/force control scheme using force and vision for docking task of a six degrees of freedom (6-dof) hydraulic…

Abstract

Purpose

The purpose of this paper is to propose a hybrid position/force control scheme using force and vision for docking task of a six degrees of freedom (6-dof) hydraulic parallel manipulator (HPM).

Design/methodology/approach

The vision system consisted of a charge-coupled device (CCD) camera, and a laser distance sensor is used to provide globe relative position information. Also, a force plate is used to measure local contact forces. The proposed controller has an inner/outer loop structure. The inner loop takes charge of tracking command pose signals from outer loop as accurate as possible, while the outer loop generates the desired tracking trajectory according to force and vision feedback information to guarantee compliant docking. Several experiments have been performed to validate the performance of the proposed control scheme.

Findings

Experiment results show that the system has good performance of relative position tracking and compliant contact. In whole docking dynamic experiment, the amplitudes of contact forces are well controlled within 300 N, which can meet perfectly the requirement of the amplitude being not more than 1,000 N.

Originality/value

A hybrid position/force control scheme using force and vision is proposed to make a 6-dof HPM dock with a moving target object compliantly.

Details

Industrial Robot: An International Journal, vol. 43 no. 3
Type: Research Article
ISSN: 0143-991X

Keywords

To view the access options for this content please click here
Article
Publication date: 26 June 2007

Carlos Marques, João Cristóvão, Paulo Alvito, Pedro Lima, João Frazão, Isabel Ribeiro and Rodrigo Ventura

To describe a robot designed and built to operate in outdoor environments hostile to the human presence, such as debris resulting from the collapse of built structures…

Abstract

Purpose

To describe a robot designed and built to operate in outdoor environments hostile to the human presence, such as debris resulting from the collapse of built structures, and targeted to the tele‐operated detection of potential survivors using a set of specific sensors whose information is transmitted to a remote human operator.

Design/methodology/approach

RAPOSA's mechanical structure is composed of a main body and a front body, whose locomotion is supported on tracked wheels, allowing motion even when the robot is upside down. The front body has variable tilting capabilities, providing means to overcome edges higher than the robot main body (e.g. when climbing a stair) and is also useful to grab the lower ground when only the main body has ground contact. This front body has one thermal camera and two webcameras installed. Additional sensors include gas, temperature and humidity sensors, web cams, light diodes, microphone and loudspeaker. The robot uses wireless communications, with an option for tethered operation.

Findings

The robot was tested in several scenarios of the Fire Fighters school. In this particular exercise, the robot reduced the inspection time down to 25 percent of the time that specialized firefighters teams would take to finish the exercise. This was due to the fact that the firefighters need to stabilize the environment in order to reduce live threats. In this case, as in many other similar situations, not only the robot provides a faster inspection method, but also a much safer one.

Originality/value

The tether carries both power and communications, with an access point on its end. Docking and undocking the robot to the tether is accomplished remotely by the operator with the help of a camera located inside the robot, and represents the most innovative feature of RAPOSA.

Details

Industrial Robot: An International Journal, vol. 34 no. 4
Type: Research Article
ISSN: 0143-991X

Keywords

To view the access options for this content please click here
Article
Publication date: 15 June 2015

Haitao Yang, Zongwu Xie, Kui Sun, Xiaoyu Zhao, Minghe Jin and Cao Li

The purpose of this paper is to develop a set of ground experiment system to verify the basic functions of space effector and the capturing reliability of space…

Abstract

Purpose

The purpose of this paper is to develop a set of ground experiment system to verify the basic functions of space effector and the capturing reliability of space end-effector for the free-floating target payload in the three-dimensional space. The development of ground experiment system for space end-effector is essential and significant, because it costs too much to launch a space robot or other spacecraft and carry out operation tasks in space. Owing to the negligible gravity in space, which is different from that in the ground environment, ground experiment system for space end-effector should have the capability of verifying the basic functions of space effector and the reliability of space end-effector in capturing the free-floating target payload in space.

Design/methodology/approach

The ground experiment system for space end-effector mainly adopts the hybrid simulation method, which includes the real hardware experiment and software simulation. To emulate the micro-gravity environment, the contact dynamics simulator is applied to emulating the motion state of the free-floating target payload, while the admittance control is used to realize the “soft” capturing of space end-effector to simulate the real situation in space.

Findings

With the gravity compensation, the influence of gravity is almost eliminated and the results meet the requirements of the experiment. In the ground experiment, the admittance control is effective and the actual motion state of space end-effector capturing the target in space can be simulated. The experiment results show that space end-effector can capture the free-floating target payload successfully and hopefully have the ability to capture a free-floating target in space.

Originality/value

The system can verify space end-effector capturing the free-floating target payload in three-dimensional space and imitate the motion of space end-effector capturing the free-floating target in space. The system can also be modified and improved for application in the verification of space robot capturing and docking the target, which is valuable for the ground verification of space applications.

Details

Industrial Robot: An International Journal, vol. 42 no. 4
Type: Research Article
ISSN: 0143-991X

Keywords

To view the access options for this content please click here
Article
Publication date: 14 June 2013

Luis de Leonardo, Matteo Zoppi, Li Xiong, Dimiter Zlatanov and Rezia M. Molfino

The use of thin sheets with 3D geometries is growing in quantity, due to current progress towards life‐cycle design and sustainable production, and growing in geometrical…

Abstract

Purpose

The use of thin sheets with 3D geometries is growing in quantity, due to current progress towards life‐cycle design and sustainable production, and growing in geometrical complexity, due to aesthetic and quality concerns. The growth in manufacturing equipment flexibility has not kept pace with these trends. The purpose of this paper is to propose a new reconfigurable fixture to shorten this gap.

Design/methodology/approach

The design implements a novel concept of fixturing. Without interrupting the machining process, a swarm of adaptable mobile agents periodically reposition and reconfigure to support the thin‐sheet workpiece near the tool‐point. The technology has been developed by adopting a multi‐disciplinary, life‐cycle approach. Modularity and eco‐sustainability paradigms have informed the design.

Findings

The performance of the physical prototype in an industrial scenario is highly satisfactory. Experiments demonstrate the ability of the system to reconfigure while maintaining machining accuracy in scenarios typical for aircraft part production.

Research limitations/implications

Coordination between the machine‐tool numerical control and the fixture control is not complete and its improvement will make the manufacturing process more robust and autonomous.

Practical implications

The system allows reduction of shop‐floor fixturing inventory. Compared to other reconfigurable fixtures, SwarmItFIX is smarter, more flexible, lighter, and offers shorter reconfiguration times, easier set‐up, and better adaptability to a wider range of workpiece shapes.

Originality/value

This is a breakthrough idea, answering the challenges of hyper‐flexible manufacturing and the proliferation of thin‐sheet use. It is of significant value to mass‐customized industry and of special significance for small‐series production.

Details

Industrial Robot: An International Journal, vol. 40 no. 4
Type: Research Article
ISSN: 0143-991X

Keywords

To view the access options for this content please click here
Article
Publication date: 14 October 2020

Xianliang Zhang, Weibing Zhu, Xiande Wu, Ting Song, Yaen Xie and Han Zhao

The purpose of this paper is to propose a pre-defined performance robust control method for pre-assembly configuration establishment of in-space assembly missions, and…

Abstract

Purpose

The purpose of this paper is to propose a pre-defined performance robust control method for pre-assembly configuration establishment of in-space assembly missions, and collision avoidance is considered during the configuration establishment process.

Design/methodology/approach

First, six-degrees-of-freedom error kinematic and dynamic models of relative translational and rotational motion between transportation systems are developed. Second, the prescribed transient-state performance bounds of tracking errors are designed. In addition, based on the backstepping, combining the pre-defined performance control method with a robust control method, a pre-defined performance robust controller is designed.

Findings

By designing prescribed transient-state performance bounds of tracking errors to guarantee that there is no overshoot, collision-avoidance can be achieved. Combining the pre-defined performance control method with a robust control method, robustness to disturbance is guaranteed.

Originality/value

This paper proposed a pre-defined performance robust control method. Simulation results demonstrate that the proposed controller can achieve a pre-assembly configuration establishment with collision avoidance in the existence of external disturbances.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 1
Type: Research Article
ISSN: 1748-8842

Keywords

1 – 10 of over 1000