Công nghệ cơ khí thường tạo ra các giả lập mô phỏng hoạt động của các đối tượng, như quy trình chế tạo thực tế theo trình tự tối ưu hóa sự thực hiện, hiệu quả kinh tế và chi phí năng lượng trước khi quyết định lựa chọn một thiết kế cụ thể. | 82 Advances in Haptics virtual object and on the contact points geometry. The contact point detection and the associated normal vector at the interface between a virtual object and a virtual foot model is evaluated by the Newton engine and dynamic proxy objects. The HDR exploits these values to compute its own reaction wrench hr and for selecting which control class to use in order to get the best haptic rendering. Cartesian Compensations Mechanism transparency is crucial when a walker has to use a mechanical device inside a virtual environment. Indeed in the virtual world the user must be able to forget the fact that he is attached and that he is using a real device. Only the simulated physics such as friction between foot and virtual object inside the virtual environment must be reproduced under the user s foot. In order for this to happen it is very important to know the exact behaviour of the mechanism at any time. This is made possible by knowing the dynamics of the device. In a locomotion interface the inertia and weight of platforms and sensors must be compensated for in order to increase the realism of the haptic display to the user. Therefore hc not only includes the variable load ha applied by a walker s foot on the platform and the set of wrenches hr computed from the interaction between walker s feet and its virtual environment but also the effect of the weight hwPF e R6 and inertia hiPF e R6 of the platform and wrench sensors. For impedance control with force feedback an additional hr is added for haptic rendering of virtual contact between the platform and the virtual object. ZpF Fig. 5. Reference frame of the platform The compensation for the mechanism inertia and weight platforms and sensors altogether is computed by dynamic wrenches hiPF and hwPF respectively. Since there are two working frames the inertial frame Gg and the moving frame attached to the end-effector GPF as described in figure 5 and no deformation is permitted to the platform .
