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The purpose of this paper is to propose an efficient path and trajectory planning method to solve online robotic multipoint assembly.

A path planning algorithm called policy memorized adaptive dynamic programming (PM-ADP) combines with a trajectory planning algorithm called adaptive elite genetic algorithm (AEGA) for online time-optimal path and trajectory planning.

Experimental results and comparative study show that the PM-ADP is more efficient and accurate than traditional algorithms in a smaller assembly task. Under the shortest assembly path, AEGA is used to plan the time-optimal trajectories of the robot and be more efficient than GA.

The proposed method builds a new online and efficient path planning arithmetic to cope with the uncertain and dynamic nature of the multipoint assembly path in the Cartesian space. Moreover, the optimized trajectories of the joints can make the movement of the robot continuously and efficiently.

The proposed method is a combination of time-optimal path planning with trajectory planning. The traveling salesman problem model of assembly path is established to transfer the assembly process into a Markov decision process (MDP). A new dynamic programming (DP) algorithm, termed PM-ADP, which combines the memorized policy and adaptivity, is developed to optimize the shortest assembly path. GA is improved, termed AEGA, which is used for online time-optimal trajectory planning in joints space.

The purpose of this paper is to develop an automatic disassembly navigation approach for human interactions in the virtual environment to achieve accurate and effective virtual assembly path planning (VAPP).

First, to avoid the error-prone human interactions, a constraint-based disassembly method is presented. Second, to automatically provide the next operable part(s), a disassembly navigation mechanism is adopted. Finally, the accurate assembly path planning can be obtained effectively and automatically by inversing the ordered accurate disassembly paths, which are obtained interactively in the virtual environment aided with the disassembly navigation matrix.

The applications present that our approach can effectively avoid the error-prone interactive results and generate accurate and effective VAPP.

There are several works that could be conducted to make our approach more general in the future: to further study the basic disassembly direction deducing rules to make the process of determining disassembly direction totally automatic, to consider the hierarchy of the parts in virtual reality system and to consider the space for assembly/disassembly tools or operators.

The approach has the following characteristics: a new approach to avoid the error-prone human interactions for accurate assembly path planning obtaining, a new constraint deducing method for determining the disassembly semantics automatically or semi-automatically is put forward and a new method for automatically identifying operable parts in VAPP is set forward.

The purpose of this paper is to propose a strategy for the final assembly of helicopter fuselage with weak rigidity parts and mismatched jointing butt ends.

The strategy is based on path planning methods. Compared with traditional path planning methods, the configuration-space and collision detection in the method are different. The obstacles in the configuration-space are weakly rigid and allow continuous contact with the robot. The collision detection is based on interference magnitudes, and the result is divided into no collision, weak collision and strong collision. Only strong collision is unacceptable. Then a compliant jointing path planning algorithm based on RRT is designed, combined with some improvements in search efficiency.

A series of planning results show that the efficiency of this method is higher than original RRT under the same conditions. The effectiveness of the method is verified by a series of simulations and experiments on two sets of systems.

There are few reports on the automation technology of helicopter fuselage assembly. This paper analyzes the problem and provides a solution from the perspective of path planning. This method contains a new configuration-space and collision detection method adapted to this problem and could be intuitive for the jointing of other weakly rigid parts.

Cables are widely used, and they play a key role in complex electromechanical products such as vehicles, ships, aircraft and satellites. Cable design and assembly significantly impact the development cycle and assembly quality, which is be-coming a key element affecting the function of a product. However, there are various kinds of cables, with complex geo-metric configurations and a narrow assembly space, which can easily result in improper or missed assembly, an unreasonable layout or interference. Traditional serial design methods are inefficient and costly, and they cannot predict problems in installation and use. Based on physical modeling, computer-aided cable design and assembly can effectively solve these problems. This paper aims to address virtual assembly (VA) of flexible cables based on physical modeling.

Much research has focused recently on virtual design and assembly-process planning for cables. This paper systematically reviews the research progress and the current state of mechanical models, virtual design, assembly-process planning, collision detection and geometric configuration and proposes areas for further research.

In the first instance, the main research groups and typical systems are investigated, followed by extensive exploration of the major research issues. The latter can be reviewed from five perspectives: the current state of mechanical models, virtual design, assembly-process planning, collision detection and geometric configuration. Finally, the barriers that prevent successful application of VA are also discussed, and the future research directions are summarized.

This paper presents a comprehensive survey of the topics of VA of flexible cables based on physical modeling and investigates some new ideas and recent advances in the area.

The purpose of this paper is to design a reasonable joining path and achieve assembly automation for multiple arc-shaped panels. A fuselage panel is primarily composed of skins, stringers, frames and clips. Both inserted and nested structures are adopted in the panels to improve the strength and hermeticity of the fuselage. Due to the complex structures and relationships, it is a challenge to coordinate the arc-shaped panels in the assembly process.

A motion sequence model which achieves arc approximation based on the relative motion of multiple panels is established. The initial position of the panels is obtained by decomposing the computer-aided design model of the panels. Two translation rules, i.e. progressively decreasing translation and limited deformation translation, are applied to determine the moving path of the panels. If a panel is not at its path node, a search algorithm is used to find the nearest path node. Finally, the key algorithms are implemented in an integration system to promote joining automation of multiple panels.

The zigzag path is effective for the joining of multiple panels with complex mating relationships. The automation of the join–separate–rejoin operations is time-saving and safety-assuring. The proposed method is demonstrated in practical engineering and a good efficiency is obtained.

This method has been used in a middle fuselage assembly project. The practical results show that the zigzag path is convenient to be stored and reused, and the synchronous movements of multiple curved panels are precisely realized. Additionally, the posture accuracy of panels is significantly improved, and the operating time is reduced considerably.

This paper gives a solution including path planning and process integration to solve the joining problem of multiple panels. The research will promote the automation of fuselage assembly.

Tool path generation is the key procedure to fabricate multi‐material (MM) assemblies in rapid prototyping (RP) machines. In slicing MM assembly, there will be 2D regions of different materials. The regions need to be filled into 2.5D slabs. In order to complete all regions in a certain slice faster, tool holders should fill the regions simultaneously. In other words, the tool holders will move around in the RP work envelope concurrently. In such case, interference between tool holders may occur. Therefore, collision‐free path plan should be generated. In this paper, a dexel based spatio‐temporal modelling approach is proposed for detecting collision in rapid manufacturing MM assemblies. The approach is based on 2D regions in dexel representation, which needs only simple computation. As a result, tool holders can fill MM regions simultaneously and efficiently.

The purpose of this paper is to develop a modeling and interactive operating method for virtual assembly (VA) to support assembly process generation based on interactive operation.

This paper puts forward an assembly semantic modeling method for interactive assembly and process generation after the analysis on requirements of operation process generation. Based on this semantic model, methods for semantic generation, semantic processing and assembly motion extraction from interactive operation are presented. Partial process generation of auto engine is proposed to verify the approaches in this paper.

The application shows that assembly semantic modeling and operating methods can support process generation based on VA operations.

The approaches presented in this paper improve the efficiency of assembly process, making assembly process intuitive and natural.

The purpose of this paper is to obtain the reasonable dimensioning for each part and a full-dimension model of assembly dimensions.

The relational path graph of assembly dimension, the shortest-path spanning tree of functional dimension and a revised spanning tree are established in this paper.

The proposed method can obtain reasonable dimensioning of parts and establishment of dimension model in an assembly.

The proposed method can easily realise by computer and be more suitable to automatic dimensioning and establishment of dimension model of parts.

Virtual reality (VR) for product assembly has been studied for more than 20 years but its practical application in industry is still very much in its infancy. Haptics is a new and important interaction method for VR and a strong and growing research area, however, it still remains a virtually unknown concept for industrial application.

This paper provides a comprehensive survey of VR and haptics for product assembly, from rigid parts to soft cables.

Some new ideas and research progresses in recent years are especially investigated. First the concepts and classifications of virtual assembly are introduced and the different virtual environment systems for product assembly are discussed. Then the major research groups, typical systems and major research issues are explored in detail, treating rigid parts and soft cables separately. Lastly, the barriers preventing successful application of virtual assembly are discussed and future research directions are also summarized.

The paper provides an overview and analysis of VR and haptics for product assembly, including both rigid parts and soft cables.

The purpose of this paper is to study the effect of the gamification of virtual assembly planning on the user performance, user experience and engagement.

A multi-touch table was used to manipulate virtual parts and gamification features were integrated into the virtual assembly environment. An experiment was conducted in two conditions: a gamified and a non-gamified virtual environment. Subjects had to assemble a virtual pump. The user performance was evaluated in terms of the number of errors, the feasibility of the generated assembly sequence and the user feedback.

The gamification reduced the number of errors and increased the score representing the number of right decisions. The results of the subjective and objective analysis showed that the number of errors decreased with engagement in the gamified assembly. The increase in the overall user experience reduced the number of errors. The subjective evaluation showed a significant difference between the gamified and the non-gamified assembly in terms of the level of engagement, the learning usability and the overall experience.

The effective learning retention after training has not been tested, and longitudinal studies are necessary. The effect of the used gamification elements has been evaluated as a whole; further work could isolate the most beneficial features and add other elements that might be more beneficial for learning.

The research reported in this paper provides valuable insights into the gamification of virtual assembly using a low-cost multi-touch interface. The results are promising for training operators to assemble a product at the design stage.