Development of a haptic virtual reality system for assembly planning and evaluation

AbstractVirtual reality systems can be used to simulate, analyze and optimize manufacturing processes including assembly. Haptic technologies enable the user to feel the force feedback from the virtual environment, leading to a more intuitive and natural way to simulate the assembly process during the design phase of new components even before any physical prototype is created. This paper presents the development of a haptic virtual reality platform to perform, plan and evaluate virtual assemblies of components. The system allows real-time manipulation and interaction of virtual components. Physics simulation engines are used to enable physic based behavior and collision detection of virtual objects in the virtual environment. One of the outstanding characteristics of the proposed platform is that the user can modify various simulation parameters during run-time, such as the weight of virtual objects, model representation algorithm and the physics simulation engine being used, which is very important in order to evaluate the influence of each parameter on the performance of virtual assembly tasks

The development of a physics and constraint based haptic virtual assembly system

Purpose – This paper aims to report the development and key features of a novel virtual reality system for assembly planning and evaluation called Haptic Assembly and Manufacturing System (HAMS). The system is intended to be used as a tool for training, design analysis and path planning. Design/methodology/approach – The proposed systemuses the physics-basedmodelling (PBM) to performassemblies in virtual nvironments.Moreover, dynamic assembly constrains have been considered to reduce the degrees of freedom of virtual objects and enhance the virtual assembly performance. Findings – To evaluate the effectiveness and performance of HAMS, the assembly of various mechanical components has been carried out, and the results have shown that it can be effectively used to simulate, evaluate, plan and automatically formalise the assembly of complex models in a more natural and intuitive way. Research limitations/implications – The collision detection performance is the bottleneck in any virtual assembly system. New methods of collision shape representation and collision detection algorithms must be considered. Originality/value – HAMS introduces the use of dynamic assembly constraints to enhance the virtual assembly performance. HAMS also uses features not yet reported by similar systems in the literature. These features include: automatic or manual definition of assembly constraints within the virtual assembly system; the implementation of control panels and widgets to modify simulation parameters during running time to evaluate its influence on simulation performance; assembly data logging such as trajectories, forces and update rates for post-processing, further analysis or its presentation in the form of chronocyclegraphs to graphically analyse the assembly process

Effect of weight perception on human performance in a haptic-enabled virtual assembly platform

Virtual assembly platforms (VAPs) provide a means to interrogate product form, fit and function thereby shortening the design cycle time and improving product manufacturability while reducing assembly cost. VAPs lend themselves to training and can be used as offline programmable interfaces for planning and automation. Haptic devices are increasingly being chosen as the mode of interaction for VAPs over conventional glove-based and 3D-mice, the key benefit being the kinaesthetic feedback users receive while performing virtual assembly tasks in 2D/3D space leading to a virtual world closer to the real world. However, the challenge in recent years is to understand and evaluate the addedvalue of haptics. This paper reports on a haptic enabled VAP with a view to questioning the awareness of the environment and associated assembly tasks. The objective is to evaluate and compare human performance during virtual assembly and real-world assembly, and to identify conditions that may affect the performance of virtual assembly tasks. In particular, the effect of weight perception on virtual assembly tasks is investigated

An evaluation of physics engines and their application in haptic virtual assembly environments

Virtual Reality (VR) applications are employed in engineering situation to simulate real and artificial situations where the user can interact with 3D models in real time. Within these applications the virtual environment must emulate real world physics such that the system behaviour and interaction are as natural as possible and to support realistic manufacturing applications. As a consequence of this focus, several simulation engines have been developed for various digital applications, including VR, to compute the physical response and body dynamics of objects. However, the performance of these physics engines within haptic-enabled VR applications varies considerably. In this study two third party physics engines - Bullet and PhysXtm- are evaluated to establish their appropriateness for haptic virtual assembly applications. With this objective in mind five assembly tasks were created with increasing assembly and geometry complexity. Each of these was carried out using the two different physics engines which had been implemented in a haptic-enabled virtual assembly platform specifically developed for this purpose. Several physics-performance parameters were also defined to aid the comparison. This approach and the subsequent results successfully demonstrated the key strengths, limitations, and weaknesses of the physics engines in haptic virtual assembly environments