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Article
Publication date: 4 January 2021

Yuxue Jin, Jie Geng, Zhiyi He, Chuan Lv and Tingdi Zhao

Virtual maintenance simulation is of great importance to help designers find and avoid design problems. During its simulation phase, besides the high precision…

Abstract

Purpose

Virtual maintenance simulation is of great importance to help designers find and avoid design problems. During its simulation phase, besides the high precision requirement, collision detection must be suitable for all irregular objects in a virtual maintenance environment. Therefore, in this paper, a collision detection approach is proposed based on encapsulation for irregular objects in the virtual maintenance environment.

Design/methodology/approach

First, virtual maintenance simulation characteristics and several commonly used bounding boxes methods are analyzed, which motivates the application of encapsulation theory. Based on these, three different encapsulation methods are oriented to the needs of simulation, including encapsulation of rigid maintenance objects, flexible maintenance objects and maintenance personnel. In addition, to detecting collisions accurately, this paper divides the detection process into two stages. That is, in the first stage, a rough detection is carried out and then a tiny slice space is constructed to generate corresponding capsule groups, which will be redetected in the secondary stage. At last, several case studies are applied to illustrate the performance of the methodology.

Findings

The automatic construction algorithm for bounding boxes can be adapted to all forms of objects. The number of detection primitives are greatly reduced. It introduces the reachable space of the human body in maintainability as the collision search area.

Originality/value

The advantages of virtual maintenance simulation could also be advantageous in the industry with further studies. The paper believes this study is of particular interest to the readers of your journal.

Details

Assembly Automation, vol. 41 no. 1
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 20 June 2019

Tie Zhang and JingDong Hong

Successful sensorless collision detection by a robot depends on the accuracy with which the external force/torque can be estimated. Compared with collaborative robots…

Abstract

Purpose

Successful sensorless collision detection by a robot depends on the accuracy with which the external force/torque can be estimated. Compared with collaborative robots, industrial robots often have larger parameter values of their dynamic models and larger errors in parameter identification. In addition, the friction inside a reducer affects the accuracy of external force estimation. The purpose of this paper is to propose a collision detection method for industrial robots. The proposed method does not require additional equipment, such as sensors, and enables highly sensitive collision detection while guaranteeing a zero false alarm rate.

Design/methodology/approach

The error on the calculated torque for a robot in stable motion is analyzed, and a typical torque error curve is presented. The variational characteristics of the joint torque error during a collision are analyzed, and collisions are classified into two types: hard and soft. A pair of envelope-like lines with an effect similar to that of the true envelope lines is designed. By using these envelope-like lines, some components of the torque calculation error can be eliminated, and the sensitivity of collision detection can be improved.

Findings

The proposed collision detection method based on envelope-like lines can detect hard and soft collisions during the motion of industrial robots. In repeated experiments without collisions, the false alarm rate was 0 per cent, and in repeated experiments with collisions, the rate of successful detection was 100 per cent. Compared with collision detection method based on symmetric thresholds, the proposed method has a smaller detection delay and the same detection sensitivity for different joint rotation directions.

Originality/value

A collision detection method for industrial robots based on envelope-like lines is proposed in this paper. The proposed method does not require additional equipment or complex algorithms, and highly sensitive collision detection can be achieved with zero false alarms. The proposed method is low in cost and highly practical and can be widely used in applications involving industrial robots.

Details

Industrial Robot: the international journal of robotics research and application, vol. 46 no. 4
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 26 August 2014

Liu Jiongzhou, Li Jituo and Lu Guodong

The 3D dynamic clothing simulation is widely used in computer-added garment design. Collision detection and response are the essential component and also the efficiency…

Abstract

Purpose

The 3D dynamic clothing simulation is widely used in computer-added garment design. Collision detection and response are the essential component and also the efficiency bottleneck in the simulation. The purpose of this paper is to propose a high efficient collision detection algorithm for 3D clothing-human dynamic simulation to achieve both real-time and virtually real simulation effects.

Design/methodology/approach

The authors approach utilizes the offline data learning results to simplify the online collision detection complexity. The approach includes two stages. In the off-line stage, model triangles with most similar deformations are first, partitioned into several near-rigid-clusters. Clusters from the clothing model and the human model are matched as pairs according to the fact that they hold the potential to intersect. For each cluster, a hierarchical bounding box tree is then constructed. In the on-line stage, collision detection is checked and treated parallelly inside each cluster pairs. A multiple task allocation strategy is proposed in parallel computation to ensure efficiency.

Findings

Reasonably partitioning the 3D clothing and human model surfaces into several clusters and implementing collision detection on these cluster pairs can efficiently reduce the model primitive amounts that need be detected, consequently both improving the detection efficiency and remaining the simulation virtual effect.

Originality/value

The current methods only utilize the dynamic clothing-human status; the authors algorithm furthermore combines the intrinsic correspondence relationship between clothing and human clusters to efficiently shrink the detection query scope to accelerate the detection speed. Moreover, partitioning the model into several independent clusters as detection units is much more profitable for parallel computation than current methods those treat the model entirety as the unit.

Details

International Journal of Clothing Science and Technology, vol. 26 no. 5
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 12 June 2018

Mingming Guo, Hua Zhang, Chuncheng Feng, Manlu Liu and Jianwen Huo

This paper aims to present a method to improve the sensitive and low probabilities of false alarm of a manipulator in a human–robot interaction environment, which can…

Abstract

Purpose

This paper aims to present a method to improve the sensitive and low probabilities of false alarm of a manipulator in a human–robot interaction environment, which can improve the performance of the system owing to non-linear uncertainty in the model of the robot controller.

Design/methodology/approach

A novel collision detection method based on adaptive residual estimation is proposed, promoting the detection accuracy of the collision of the manipulator during operation. First, a general momentum residual estimator is designed to incorporate the non-linear factors of the manipulator (e.g. joint friction, speed and acceleration) into the residual-related uncertainty of the model. Second, model parameters are estimated through gradient correction. The residual filter is used to determine the dynamic threshold, resulting in higher detection accuracy. Finally, the performance of the residual estimation scheme is evaluated by comparing the dynamic threshold with residual in real-time experiments where a single Universal Robot 5 robot end–effector collides with the obstacle.

Findings

Experimental results demonstrate that the collision detection system can improve sensitivity and lead to low probabilities of false alarm of non-linear uncertainty in the model.

Practical implications

The method proposed in this article can be applied to industry and human–robot interaction area.

Originality/value

An adaptive collision detection method is proposed in this paper to address non-linear uncertainties of the model in industrial application.

Details

Industrial Robot: An International Journal, vol. 45 no. 3
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 15 June 2010

In Hwan Sul

The purpose of this paper is to develop a new and simple methodology for fabric collision detection and response.

Abstract

Purpose

The purpose of this paper is to develop a new and simple methodology for fabric collision detection and response.

Design/methodology/approach

A 3D triangle‐to‐triangle collision problem was converted to simple 2D point‐in‐triangle problem using pre‐computed 4×4 transformation matrices. The object space was partitioned using voxels to find easily collision pair triangles. k‐DOP was used to find inter‐pattern collisions.

Findings

Complex 3D collision detection problem is solved by simple matrix operations. Voxel‐based space partitioning and k‐DOP‐based hierarchical methods are successfully applied to garment simulation.

Originality/value

This paper shows that the collision matrix method can cover from triangle‐to‐point to triangle‐to‐triangle collision with mathematical validity and can be simply implemented in garment simulation.

Details

International Journal of Clothing Science and Technology, vol. 22 no. 2/3
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 1 December 2005

Shujun Lu and Jae H. Chung

Aims to make an industrial robot work human‐friendly while coexisting with humans in a same working space, without any modification of the manipulator hardware as well as…

Abstract

Purpose

Aims to make an industrial robot work human‐friendly while coexisting with humans in a same working space, without any modification of the manipulator hardware as well as its motion controller.

Design/methodology/approach

Presents a weighted path planning approach based on collision detection for a robot sharing the same workspace with humans. Using a base and wrist force/torque sensors, a model‐based method is investigated to estimate the collision force and collision position on the manipulator; then a weighted path planning approach is developed to control the human‐robot interaction. Simulation experiments, with collisions between the manipulator and static objects and moving objects, are conducted to validate the efficacy of the method.

Findings

The experimental results illustrate the validity of the developed collision detection and planning scheme and make it possible for industrial robots to work safely around humans. The proposed weighted path planner (WPP) outperforms other three path planners.

Originality/value

Introduces the WPP based on collision detection. The wrist and base force/torque sensors configuration has the friction free benefit, and the developed method does not modify the existing designs of industrial robots. The contact force is well controlled under the human pain tolerance limit, through the modification of the desired path, and does not need torque control which is usually not available to industrial robots.

Details

Industrial Robot: An International Journal, vol. 32 no. 6
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 19 November 2019

Pengcheng Wang, Dengfeng Zhang and Baochun Lu

This paper aims to address the collision problem between robot and the external environment (including human) in an unstructured situation. A new collision detection and…

Abstract

Purpose

This paper aims to address the collision problem between robot and the external environment (including human) in an unstructured situation. A new collision detection and torque optimization control method is proposed.

Design/methodology/approach

Firstly, when the collision appears, a second-order Taylor observer is proposed to estimate the residual value. Secondly, the band-pass filter is used to reduce the high-frequency torque modeling dynamic uncertainty. With the estimate information and the torque value, a variable impedance control approach is then synthesized to guarantee that the collision is avoided or the collision will be terminated with different contact models and positions. However, in terms of adaptive linear force error, the variation of the thickness of the boundary layer is controlled by the new proximity function.

Findings

Finally, the experimental results show the better performance of the proposed control method, realizing the force control during the collision process.

Originality/value

Origin approach and origin experiment.

Details

Industrial Robot: the international journal of robotics research and application, vol. 47 no. 6
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 1 March 1998

G. Stylios and T.R. Wan

This paper presents a new technique for collision detection between fabric and fabric or fabric and body, applied on our physical‐based fabric drape model. The technique…

Abstract

This paper presents a new technique for collision detection between fabric and fabric or fabric and body, applied on our physical‐based fabric drape model. The technique can produce a realistic 3D virtual fashion show based on fabric mechanical properties and has the ability to handle the collision of clothing with an animated synthetic human. The collision technique appeared efficient and reliable when dealing with complex cases of fabric deformation. A full implementation of the drape model, collision detection with an animated human model is also described and discussed.

Details

International Journal of Clothing Science and Technology, vol. 10 no. 1
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 30 June 2021

Oualid Araar, Kheireddine Benjdia and Ivan Vitanov

The widespread use of drones among the general public has led to an alarming increase in accidents, some with lethal consequences. As drone blades are made from rigid…

Abstract

Purpose

The widespread use of drones among the general public has led to an alarming increase in accidents, some with lethal consequences. As drone blades are made from rigid materials and rotate at very high speeds, their impact with a human body can result in fatal injuries. Reliable collision detection combined with near-instantaneous braking of the drone’s rotor(s) can substantially lessen the severity of injuries sustained. The purpose of this paper is to achieve a safety solution which can be easily integrated into new products, or retrofitted into existing systems.

Design/methodology/approach

Through a proof of concept, this paper demonstrates the possibility of detecting a collision with a drone propeller absent any hardware modifications to the drone’s instrumentation. The solution relies on current-sensor readings, ordinarily used for monitoring the battery status of electrically actuated drones. The braking is achieved purely by reconfiguring the motor’s control strategy, without the need for additional hardware, as has been the case in previous works.

Findings

This paper demonstrates the possibility of detecting a collision with a drone propeller absent any hardware modifications to the drone’s instrumentation.

Originality/value

Compared to previous works which require installing additional hardware, the solution is purely software. This makes it very easy to integrate into existing systems or new products, at no additional cost. In experiments conducted on a prototype system, the solution was shown capable of detecting a collision and braking the motor in fewer than 20 ms. This allowed attenuating centimetre-deep cuts made to a piece of meat by an unprotected rotor to mere superficial scratches.

Details

Aircraft Engineering and Aerospace Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 19 March 2020

Wenlei Zhang, Mingxu Ma, Haiyan Li, Jiapeng Yu and Zhenwei Zhang

The purpose of this paper is to discriminate fake interference caused by polygonal approximation so as to achieve accurate assembly sequence planning and assembly simulation.

Abstract

Purpose

The purpose of this paper is to discriminate fake interference caused by polygonal approximation so as to achieve accurate assembly sequence planning and assembly simulation.

Design/methodology/approach

An approximation zone model is proposed to formulate polygonal approximation. Fake interference is discriminated from hard interference by evaluating if polygonal models intersect within corresponding approximation zones. To reduce the computation, the surface-surface, surface-end face and end face-end face intersection test methods have been developed to evaluate the intersection and obtain collision data. An updated collision detection algorithm with this method is presented, which is implemented by a system named AutoAssem.

Findings

This method has been applied to a set of products such as a valve for assembly interference matrix generation, static and dynamic collision detection. The results show that it ensures the accuracy of assembly sequence planning and assembly simulation for polygonal models.

Practical implications

This method facilitates assembly design in the virtual environment with polygonal models. It can also be applied to computer aided design systems to achieve quick and accurate collision detection.

Originality/value

Fake interference between polygonal models may result in serious errors in assembly sequence planning and assembly simulation. Assembly zone model and novel polygon intersection verification methods have been proposed to effectively tackle this problem. Compared to current methods, this method considers valid penetration direction and approximation difference, does not need to process complicated auxiliary data and can be easily integrated with current collision detection methods.

Details

Assembly Automation, vol. 40 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

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