Jean-Yves Fourquet

Using virtual reality and 3D industrial numerical models for immersive interactive checklists

At the different stages of the PLM, companies develop numerous checklist-based procedures involving prototype inspection and testing. Besides, techniques from CAD, 3D imaging, animation and virtual reality now form a mature set of tools for industrial applications. The work presented in this article develops a unique framework for immersive checklist-based project reviews that applies to all steps of the PLM. It combines immersive navigation in the checklist, virtual experiments when needed and multimedia update of the checklist. It provides a generic tool, independent of the considered checklist, relies on the integration of various VR tools and concepts, in a modular way, and uses an original gesture recognition. Feasibility experiments are presented, validating the benefits of the approach.

Coupling manipulation and locomotion tasks for a humanoid robot

This work deals with the use of tools from robotics for generating whole-body movements on anthropomorphic systems. The problem of coordinating the whole-body joints in order to combine manipulation and locomotion tasks is considered. Using inverse kinematics, the main scientific challenge comes from redundancy. We tackle it by considering a main equality task and additional inequality constraints. These secondary constraints are expressed by repulsive and attractive potential functions. Using this type of function, we provide a relaxation on the positioning of the projected center of mass into the support polygon, in order to increase the accessibility of the robot during reaching tasks. These methods were implemented on Matlab and the motion was simulated on the dynamic simulator OpenHRP of the HRP2 humanoid robot.

Generation of human-like motion on anthropomorphic systems using inverse dynamics.

This work deals with the generation of human-like nwhole-body movements on anthropomorphic nsystems. We propose a general framework to ngenerate robot movements from the definition of nordered stack of tasks and a global resolution nscheme that enables to consider different kinds of nconstraints. We compare qualitatively the robot nmovements generated from this software with nsimilar recorded human movements. We start with a ndirect global comparison of body movements. Then nwe analyze the magnitude of the reconstructed nhuman torques and compare with the simulated nrobot torques during the motion.

I-RRT-C: Interactive motion planning with contact

This work deals with interactive motion planning processes intended to assist a human operator when simulating industrial tasks such as assembly, maintenance or disassembly in Virtual Reality. Such applications need motion planning on surfaces. We propose an original interactive path planning algorithm with contact, I-RRT-C, based on a RRT-Connect approach. This algorithm is based on a real-time interactive approach allowing both an automatic motion planner and a human operator to jointly explore the workspace. A parameter balances the authority between the computer and the operator to reduce processing times. We improve the guidance by allowing to sample on the surfaces of obstacles. Our method allows to find a path in cluttered environments or to solve contact operations such as insertion or sliding tasks. Last, we present experimental results showing that our interactive path planner with contact brings a significant improvement over state of the art methods in both free and contact space.

On the collaboration of an automatic path-planner and a human user for path-finding in virtual industrial scenes

This paper describes a global interactive framework enabling an automatic path-planner and a user to collaborate for finding a path in cluttered virtual environments. First, a collaborative architecture including the user and the planner is described. Then, for real time purpose, a motion planner divided into different steps is presented. First, a preliminary workspace discretization is done without time limitations at the beginning of the simulation. Then, using these pre-computed data, a second algorithm finds a collision free path in real time. Once the path is found, an haptic artificial guidance on the path is provided to the user. The user can then influence the planner by not following the path and automatically order a new path research. The performances are measured on tests based on assembly simulation in CAD scenes.

Tuning interaction in motion planning with contact

This work deals with planning processes for the assistance to manipulation in order to simulate industrial tasks such as assembly, maintenance or disassembly in Virtual Reality. This paper presents a novel interactive path planning algorithm with contact based on an BiRRT approach. First, we propose a real-time interactive planner where both a computer and a human operator simultaneously search the workspace therefore largely speeding up the process. An authority sharing parameter can control the autonomy of the computer. Then we present a novel contact-space algorithm able to sample on the surface of obstacles. This method helps finding paths in cluttered environments or solving specific contact tasks such as insertion or sliding operations. We finish by presenting the results of our interactive path planner with contact through three examples showing significant improvement over usual methods in both free and contact space.

H-RRT-C: Haptic motion planning with contact

This paper focuses on interactive motion planning processes intended to assist a human operator when simulating industrial tasks in Virtual Reality. Such applications need motion planning on surfaces. We propose an original haptic path planning algorithm with contact, H-RRT-C, based on a RRT planner and a real-time interactive approach involving a haptic device for computer-operator authority sharing. Force feedback allows the human operator to keep contact consistently and provides the user with the feel of the contact, and the force applied by the operator on the haptic device is used to control the roadmap extension. Our approach has been validated through two experimental examples, and brings significant improvement over state of the art methods in both free and contact space to solve path-planning queries and contact operations such as insertion or sliding in highly constrained environments.

Hierarchic Interactive Path Planning in Virtual Reality

To save time and money while designing new products, industry needs tools to design, test and validate the product using virtual prototypes. These virtual prototypes must enable to test the product at all Product Life-cycle Management (PLM) stages. Many operations in PLM involve human manipulation of product components in cluttered environment (product assembly, disassembly or maintenance). Virtual Reality (VR) enables real operators to perform these tests with virtual prototypes. This work introduces a novel path planning architecture allowing collaboration between a VR user and an automatic path planning system. It is based on an original environment model including semantic, topological and geometric information, and an automatic path planning process split in two phases: coarse (semantic and topological information) and fine (semantic and geometric information) planning. The collaboration between VR user and automatic path planner is made of 3 main aspects. First, the VR user is guided along a pre-computed path through a haptic device whereas he VR user can go away from the proposed path to explore possible better ways. Second the authority of automatic planning system is balanced to let the user free to explore alternatives (geometric layer). Third the intents of VR user are predicted (on topological layer) to be integrated in the re-planning process. Experiments are provided to illustrate the multi-layer representation of the environment, the path planning process, the control sharing and the intent prediction.

A multi-layer approach of interactive path planning for assisted manipulation in virtual reality

This work considers Virtual Reality (VR) applications dealing with objects manipulation (such as industrial product assembly, disassembly or maintenance simulation). For such applications, the operator performing the simulation can be assisted by path planning techniques from the robotics research field. A novel automatic path planner involving geometrical, topological and semantic information of the environment is proposed for the guidance of the user through a haptic device. The interaction allows on one hand, the automatic path planner providing assistance to the human operator, and on the other hand, the human operator to reset the whole planning process suggesting a better suited path. Control sharing techniques are used to improve the assisted manipulation ergonomics by dynamically balancing the automatic path planner authority according to the operator involvement in the task, and by predicting users intent to integrate it as early as possible in the planning process.

A Multi-layer Approach for Interactive Path Planning Control in Virtual Reality Simulation

His work considers path-planning processes for manipulation tasks such as assembly, maintenance or disassembly in a Virtual Reality (VR) context. The approach consists in providing a collaborative system associating a user immersed in VR and an automatic path planning process. It is based on an novel environment model containing semantic, topological and geometric information and an original planning process split in two phases: coarse and fine planning. The automatic planner suggests a path to the user and guides him trough a hap tic device. The user can escape from the proposed solution if he wants to explore a possible better way. In this case, the interactive system detects the users intention and computes in real-time a new path taking the users intent into account. Experiments illustrate the different aspects of the proposed approach: multi-representation of the environment, path planning process, users intent prediction and control sharing.